Recombinant interleukin-2 stimulates lymphocyte recovery in severe patients with COVID-19

Recombinant interleukin-2 stimulates lymphocyte recovery in severe patients with COVID-19 | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Recombinant interleukin-2 stimulates lymphocyte recovery in severe patients with COVID-19 Meng‘en Zhu, Qian Wang, Shaoqiong Zhou, Bin Wang, Li Ke, Ping He This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-40006/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 18 Jan, 2021 Read the published version in Experimental and Therapeutic Medicine → Version 1 posted You are reading this latest preprint version Abstract Object: A recently developing pneumonia called COVID-19 which caused by SARS-CoV-2 has quickly spread across the world. Lymphopenia and a proinflammatory cytokine storm frequently happened in severe COVID-19 patients. But no specific immunomodulate therapy on COVID-19 had been reported. In this retrospect case control study, we observed the potential therapeutic effect of recombinant human interleukin-2 (rIL-2) on severe COVID-19 patients in a hospital in Wuhan, China. Methods: Fifty nine severe cases with COVID-19 admitted in hospital from January 29, 2020 to February 29, 2020 were included in this study. Twenty patients received a one-week to 10 days subcutaneous injection of the recombinant human interleulin-2 1 million IU per day other than regular treatment were classified as rIL-2 group. Twenty from thirty nine patients with regular treatment without intervention of rIL-2 were matched as the control group. Clinical characteristic such as age, gender, symptoms, signs, laboratory data and comorbidities were paired in these two groups. Changes of lymphocytes counts, IL-6 and C- reactive protein (CRP) before and after rIL-2 treatment and differences between rIL-2 group and non-rIL-2 group were analyzed. Results: There were a clearly visible increasing in lymphocyte counts and a decreasing in CRP level in non rIL-2 group and rIL-2 group. The difference of the change of lymphocyte counts were significant in rIL-2 group and non-rIL-2 group (p0.05). Conclusion: RIL-2 might be a prospective adjuvant therapy for severe COVID-19 patients by increasing lymphocytes number. Immunology Epidemiology Clinical Pharmacology COVID-19 recombinant human interleukin-2 lymphopenia cytokine C-reactive protein Figures Figure 1 Introduction The corona virus disease 2019 (COVID–19), caused by severe acute respiratory syndrome coronavirus–2 (SARS-CoV–2) has spread out in the world, posing a critical threat to global health 1 . In the early stage of COVID–19, patients usually manifested a normal or lowering white blood cell count in peripheral blood, a remarkable decreasing of lymphocytes count and increasing of CRP. In the advanced stage of COVID–19, numerous inflammatory cytokines such as interleukins, tumor necrosis factor and chemokines were released and attacked the immune organs and tissues. That induced inflammatory storm and led to disease progression and multiple organ failure 2 ,3. The degree of lymphopenia and a proinflammatory cytokine storm happened more frequently in severe COVID–19 patients than in mild cases, and are associated with the disease severity 4 Recently, it was reported that CD4+ T cells decreased remarkably in patients in the early recovery stage of COVID–19. It revealed that IL–2, IL–18, IL–4 and TNFSF13 might be beneficial for the recovery of COVID–19 patients 5. However, the role of these cytokines might play in the therapy of COVID–19 had not known yet. Our study applied rIL–2, an immumodulator usually used in treatment of cancer, to the therapy of COVID–19 and investigated the changes of peripheral blood white blood cells count, lymphocytes count, levels of IL–6 and CRP. Moreover, the side effect of rIL–2 was observed simultaneously. That would make a sense of the effect and safety of rIL–2 on the treatment of COVID–19. Methods Study design and participants This is a retrospective single-center case control study included 59 severe cases with COVID–19. The patients were admitted to the West campus of Union Hospital, Tongji Medical College Huazhong University of Science and Technology (Wuhan, China), from January 29, 2020 to February 29, 2020. COVID–19 was diagnosed by meeting the criteria of epidemiology and clinical syndrome, chest computerized tomography (CT) and lymphocyte manifestations and confirmed by real-time reverse transcription- polymerase chain reaction (RT-PCR) detection for routine pharyngeal swab specimens according to the New Coronavirus Pneumonia Prevention and Control Program (6th edition) published by the National Health Commission of China 6 . The final date of follow up was April 15, 2020. Adult severe cases were diagnosed when any of the following criteria was met: (1) Respiratory distress (≧30 breaths/ min); (2) Oxygen saturation≤93% at rest; (3) Arterial partial pressure of oxygen (PaO2)/ fraction of inspired oxygen (FiO2)≤300mmHg (lmmHg = 0.133kPa). Patients who received a one-week to 10 days subcutaneous injection of the recombinant interleulin–2 one million IU per day (rIL–2, Beijing sihuan pharmaceutical factory, production batch number 20190915) treatment during hospitalization were classified as rIL–2 group. Patients who did not receive rIL–2 during hospitalization were classified as non-rIL–2 group. Propensity score-matched cohorts were created based on variables which were expected to be potential confounders associated with exposure to rIL–2, including age, gender, fever, fatigue, cough, comorbidities (hypertension, coronary heart disease, diabetes, and cerebrovascular disease) and in-hospital medications. The rIL–2 group and non-rIL–2 group were paired at 1:1 according to the propensity scores using exact matching with a caliper size of 0.05. We used the following inclusion and exclusion criteria to determine the study population. The inclusion criteria was aged over 18 years severe COVID–19 patients admitted in the hospital. The exclusion criteria included incomplete medical records (e.g., transfer to any other hospital), pregnancy, not survive during hospitalization, not controlled fever, severe hepatic dysfunction and severe renal dysfunction. The study protocols were approved by the ethics committee of Union Hospital, Tongji Medical College Huazhong University of Science and Technology. Data collection Following data were collected including patient demographic information, clinical characteristics, laboratory data, history of comorbidities and therapeutic interventions during the hospitalization. The patient demographic information (age and gender) and clinical characteristics (fever, cough and fatigue) were collected from electronic medical system. Laboratory data (blood cell count, IL- 6, CRP, hepatic function and renal function) were collected from laboratory information system. Comorbidities (hypertension, coronary heart disease, diabetes and cerebrovascular diseases) were extracted from medical history. The in-hospital medications and interventions were collected from doctor’s advice. Personal health identifying information ( e.g., name and ID) was anonymized and each participant was given a study ID using an electronic coding system before data extraction to preserve patient privacy. Data were carefully reviewed and confirmed by experienced physicians and were double-checked to guarantee the accuracy of the data extraction procedures. Statistical analysis Continuous variables were expressed as median and interquartile range (IQR), and categorical variables were expressed as number and percentage (%). Statistical differences between two groups were analyzed using the Mann-Whitney test or χ2 test. A two-side α less than 0.05 was considered statistically different. Data were analyzed in SPSS Statistics (version 23.0, IBM, Armonk, NY, USA). Results Participants From January 29, 2020 to to February 29, 2020, 72 adult patients were hospitalized. After excluding five death cases, three were transferred to other hospitals, two with not controlled fever, one with severe hepatic dysfunction and two with severe renal dysfunction, a total of 59 patients were included in this study. There were 20 patients accepted rIL–2 treatment. Twenty patients were chosen and paired with the rIL–2 group from the 39 patients of non-rIL–2 group (Figure 1). The clinical data of patient demographic information and history of comorbidities were collected on admission. Symptoms, signs and laboratory data were collected before and after rIL–2 treatment in rIL–2 group and at the same time point in non-rIL–2 group. The in-hospital medications and interventions were obtained during the hospitalization. The length of hospital stay were collected at the time of patients discharged from hospital. Baseline Characteristics of the participants and between groups As shown in Table 1, the median age of all patients was 56 years ( 48, 64), ranging from 23 years to 88 years, among whom 54.24% were male. Comorbidities such as hypertension (28.81%), diabetes (15.25%), coronary heart disease (6.78%) and cerebrovascular disease (10.17%) were common. The symptoms before rIL–2 intervention of fatigue (49.15%) and cough (77.97%) were observed in most patients. There were 69.49% patients with fever on admission. After treatment no patient included in the study had fever. All patients’ white blood cell counted in a median of 5.90(4.2，7.2)×109/L, neutrophil in a median of 3.98（2.8，5.1）×109/L and lymphocyte in a median of 0.980（0.8，1.4）×109/L. High serum IL–6 level with a median of 6.420 (1.5，16.2) pg/mL and high CRP with a median of 27.220 (4.7，48.2) mg/L were demonstrated. During hospitalization, 53 (89.83%) patients accepted antiviral drugs therapy, 44 (74.58%) patients accepted antibiotics drugs therapy, 5 (10.17%) patients accepted systemic corticosteroids therapy and 56 (94.92%) patients accepted traditional Chinese medicine therapy. The above clinical characteristics in both groups before and after matching did not have significant difference. Comparison of laboratory results in rIL–2 group patients before and after rIL–2 treatment An obvious rising of lymphocyte count was detected after rIL–2 plus regular treatment, which was 1.935 (1.6, 3.0)×109/L compared to 1.110 (0.9, 1.4)×109/L before rIL–2 treatment in rIL–2 group ( p <0.01). The CRP showed a significant decreasing after rIL–2 plus regular treatment, which lowered from 21.740 (0.5, 65.1) mg/L to 3.965 (1.5, 5.7) mg/L ( p 0.05). The neutrophils count was 3.075 (2.2, 4.3)×109/L in rIL–2 group after rIL–2 treatment, that was similar with 3.830 (2.8, 4.9)×109/L before rIL–2 treatment ( p >0.05). The IL–6 were 7.765 (1.6, 21.7) pg/mL before rIL–2 treatment. After rIL- 2 treatment, the IL–6 decreased to 3.730 (1.5, 7.7) pg/mL. But the decreasing did not get significant difference ( p >0.05). There were no obvious difference in hemoglobin (Hb) levels, platelet (PLT) count, alanine aminotransferase (ALT) levels, aspartate aminotransferase (AST) levels, blood urea nitrogen (BUN) levels and serum creatinine (Scr) levels before and after rIL–2 treatment (130.5 [123.0, 148.8] g/L vs 128.0 [120.3, 138.8] g/L, 165.5 [132.5, 243.0] ×109/L vs 215.5 [117.8, 254.5] ×109/L, 43.0 [30.0, 59.5] U/L vs 52.0 [24.8, 67.8] U/L, 29.5 [21.0, 36.8] U/L vs 28.0 [19.0, 31.0] U/L, 4.845 [3.5, 7.4] mmol/L vs 4.305 [3.6, 5.1] mmol/L, 69.500 [58.7, 78.7] μmol/L vs 65.550 [54.3, 73.8]μmol/L, repectively. All p >0.05) (Table 2). Comparison of laboratory results in non-rIL–2 group patients before and after rIL–2 treatment There were a clearly visible increasing in lymphocyte count from 0.875 (0.7, 1.3)×109/L to 1.275 (1.0, 1.6)×109/L (p<0.01) and a decreasing in CRP level from 29.930 (7.6, 47.8) mg/L to 4.585 (2.8, 12.1) mg/L ( p 0.05), neutrophils count (3.755 [2.5, 6.2]×109/L, 3.925 [2.8, 5.8]×109/L, p >0.05) and serum IL–6 levels (6.070 [1.5, 15.9] pg/mL, 2.445 [1.5, 8.0] pg/mL, p >0.05). In addition, regular treatment had no effect on Hb levels, PLT count, ALT levels, AST levels, BUN levels and Scr levels (123.500 [110.8, 139.8]g/L vs 131.000 [102.0, 137.8]g/L, 195.500 [156.5, 270.5]×109/L vs 217.000 [177.8, 342.8]×109/L, 25.500 [20.3, 52.3] U/L vs 31.500 [20.0, 49.8]U/L, 34.000 [24.5, 44.5] U/L vs 25.500 [18.3, 33.8]U/L, 4.480 [3.2, 5.5] mmol/L vs 4.405 [3.3, 5.9] mmol/L, 61.150 [52.0, 74.8] μmol/L vs 60.600 [53.8, 68.5]μmol/L, repectively. All p >0.05) (Table 2). Comparison of laboratory results in rIL–2 group and non-rIL–2 group patients after rIL–2 treatment Compared to non-IL–2 group, rIL–2 group had a significant higher level of lymphocytes, which was 1.935 (1.6, 3.0)×109/L in rIL–2 group vs 1.275 (1.0, 1.6)×109/L in non-rIL–2 group ( p 0.05). There were no difference in WBC count, neutrophils count and IL–6 levels between the two groups (6.935 [5.2, 8.3]×109/L vs 6.075 [4.6, 7.7]×109/L, p >0.05; 3.075 [2.2,4.3]×109/L vs 3.925 [2.8, 5.8]×109/L, p >0.05; 3.730 [1.5, 7.7] pg/mL vs 2.445 [1.5, 8.0] pg/mL, p >0.05, respectively). The length of hospital stay between the two groups made no difference (34.00 [20.09，47.91] days vs 32.70 [17.07，48.33] days, p >0.05) (Table 2). Drug associated adverse effects of rIL–2 treatment After regular treatment such as antiviral drugs, antibiotics, corticosteroids and traditional Chinese medicine, all participants were in normal temperature. In rIL–2 treatment group, 4 (20%) cases of fever associated with rIL–2 were reported with the temperature lowered than 38.5℃ for less than 4 days. The patients complained muscle soreness accompanied with fever. No patients with new fever onset was reported in non-rIL–2 group. The difference was significant (p0.05) (Table 2). Discussion Recent studies have shown that lymphopenia was one of the typical laboratory abnormalities of COVID–19 4–8. Lymphopenia was observed in 44.4% (12/27) of mild patients and 84.6% (11/13) of severe patients at the onset of COVID–19. The absolute counts of lymphocytes in the peripheral blood of the severe patients was significantly decreased at the time point of disease onset and became even greater on 4–6 days later. From 7 to 15 days after disease onset, the lymphocyte counts gradually increased in the severe patients, and reached a comparable level to that of the mild patients at 16 days after disease onset. Sustained decreases in CD3+ , CD8+ and CD4+ T cell counts were also observed in the severe patients 4 . CD4+ T cells decreased remarkably in patients in the early recovery stage of COVID–19. T and B cell clones were highly expanded during the recovery stage in COVID–19 patients 5. Increasing data from cohort studies and clinical trials had shown that higher CD4+ T-cell counts were associated with reductions in morbidity and mortality from both AIDS and serious non-AIDS conditions, including cardiovascular disease 9 . All these observations revealed that it might be a prospective therapy for COVID–19 to increase lymphocytes number especially CD4+ T cells. In previous studies and clinical trials rIL–2 has proven an effective means to enhance the efficacy of antitumor immunotherapy 10 . Several studies demonstrated that rIL–2 showed an immunomodulator effect in virus infections. An in vivo study in the immunocompetent BALB/c mouse reported repeated application of rhIL–2 significantly enhanced the antiviral effect of the low initial number of lymphocytes in several tissues in prophylaxis and also in therapy 11 . In a prospective cohort study in patients with HIV, CD4+ T-cell counts were observed be increased after rIL–2 treatment 12. Low-dose recombinant human IL–2 selectively modulated CD4(+) T cell subsets in patients with systemic lupus erythematosus and markedly reduced the activity of disease 13. In this study, we observed that rIL–2 could increase lymphocytes number in peripheral blood. CRP level showed a remarkable decrease after rIL–2 treatment compared with rIL–2 treatment before, but the difference between rIL–2 group and non rIL–2 group did not reach a significant point ( p >0.05). Also the clinical outcome of the length of hospital stay was observed unaffected by rIL-2. Recently it was reported that T cells produced IL–2 promoted survival, proliferation, and differentiation and antibodies production of B cells in COVID–19 patients. Consequently, B cells produce numerous SARS-COV–2- specific antibodies to clear viruses 5 ,14. Additional supplying of rIL–2 to COVID–19 patients stimulated lymphocyes recovery might have potential therapeutic effect including: First, the rising of lymphocytes might be associated with the changes of T cell subsets especially the rising of CD4+ T cells. Second, rIL–2 might mimick the effect of native IL- 2 and stimulate survival, proliferation, and differentiation and antibodies production of B cells, which accelerated the clearance of virus. Third, rIL–2 might relieve inflammation storm by decreasing the levels of cytokines. The precise mechanisms still required more data to be elucidated. The rIL–2 was tolerated in the severe COVID–19 patients. Only four adverse events were reported in rIL–2 group. The adverse reactions were fever (lower than 38.5℃) and muscle soreness. All adverse events reported were mild, transient and totally relieved after stopping rIL–2 treatment. Additionally, no abnormal changes in laboratory measurements were clinically significant or considered to be related to rIL–2. For the dose of rIL–2 used in this study was ultra-low (≤1 million IU /day), the adverse reaction of venous thromboembolism detected by ultrasound had not been obtained. There are some limitations in the present study. It was a retrospective single-center case control study. The hospital was assigned by government to accept mostly severe and critical COVID–19 patients. Only severe COVID–19 patients were included in this study. These might cause some selective bias. The results of this study are limited by the small size of the cohort and the short duration of rIL–2 treatment. Also the effect of different dosage of rIL–2 impacted on different stage of COVID–19 had not been observed. In conclusion, rIL–2 might be used as a prospective therapy in severe COVID–19 patients for it might potentially improve the recovery of disease by increasing lymphocytes number. Declarations The participators/patients reported in our paper consented to participate and/or publish. We thank all participators/patients involved in the study. Author contribution PH and MEZ designed study, performed statistical analysis and wrote manuscript. MEZ, QW，BW，SQZ and LK collected data. All authors have approved the final version of this paper. Acknowledgments We acknowledge all health-care workers from Beijing, Hainan and Anhui medical teams involved in the diagnosis and treatment of patients in the Union Hospital, Tongji Medical College Huazhong University of Science and Technology. Sources of funding None. Disclosures None. References WHO. Situation Report-68. Shimabukuro-Vornhagen, et al. Cytokine release syndrome. J Immunother Cancer 6 , 56, doi:10.1186/s40425-018-0343-910.1186/s40425-018-0343-9 [pii] (2018). Huang, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 395 , 497-506, doi:S0140-6736(20)30183-5 [pii]10.1016/S0140-6736(20)30183-5 (2020). Liu, et al. Longitudinal characteristics of lymphocyte responses and cytokine profiles in the peripheral blood of SARS-CoV-2 infected patients. EBioMedicine 55 , 102763, doi:S2352- 3964(20)30138-9 [pii]10.1016/j.ebiom.2020.102763 (2020). Wen, et al. Immune cell profiling of COVID-19 patients in the recovery stage by single- cell sequencing. Cell Discov 6 , 31, doi:10.1038/s41421-020-0168-9 168 [pii] (2020). Wang, et al. Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus-Infected Pneumonia in Wuhan, China. JAMA, doi:10.1001/jama.2020.1585 2761044 [pii] (2020). Chen, et al. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet 395 , 507-513, doi:S0140-6736(20)30211-7 [pii] 10.1016/S0140-6736(20)30211-7 (2020). Chen, et al. Clinical and immunological features of severe and moderate coronavirus disease 2019. J Clin Invest 130 , 2620-2629, doi:10.1172/JCI137244 137244 [pii] (2020). Pett, L., Kelleher, A. D. & Emery, S. Role of interleukin-2 in patients with HIV infection. Drugs 70 , 1115-1130, doi:10.2165/10898620-000000000-00000 3 [pii] (2010). Mahmoudpour, H. et al. Safety of low-dose subcutaneous recombinant interleukin-2: systematic review and meta-analysis of randomized controlled trials. Sci Rep 9 , 7145, doi:10.1038/s41598-019-43530-x 10.1038/s41598-019-43530-x [pii] (2019). Reddehase, J., Mutter, W. & Koszinowski, U. H. In vivo application of recombinant interleukin 2 in the immunotherapy of established cytomegalovirus infection. J Exp Med 165 , 650-656, doi:10.1084/jem.165.3.650 (1987). Crespo, et al. Efficacy of recombinant interleukin-2 (rIL-2) in patients with advanced HIV- 1 infection and blunted immune response to HAART. Enferm Infecc Microbiol Clin 26 , 27- 31, doi:S0213-005X(08)72648-X [pii] 10.1157/13114392 (2008). He, et al. Low-dose interleukin-2 treatment selectively modulates CD4(+) T cell subsets in patients with systemic lupus erythematosus. Nat Med 22 , 991-993, doi:10.1038/nm.4148 nm.4148 [pii] (2016). Zhou, et al. Aberrant epigenetic and genetic marks are seen in myelodysplastic leukocytes and reveal Dock4 as a candidate pathogenic gene on chromosome 7q. J Biol Chem 286 , 25211-25223, doi:10.1074/jbc.M111.235028 M111.235028 [pii] (2011). Tables Due to technical limitations, Tables 1-2 are provided in the Supplementary Files section. Supplementary Files Tables.docx Cite Share Download PDF Status: Published Journal Publication published 18 Jan, 2021 Read the published version in Experimental and Therapeutic Medicine → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-40006","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":761237,"identity":"91fd4c90-654d-407c-88dd-1582b1f637df","order_by":0,"name":"Meng‘en Zhu","email":"","orcid":"","institution":"Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Meng‘en","middleName":"","lastName":"Zhu","suffix":""},{"id":761238,"identity":"06812cc2-1e26-4c05-8d35-f8dea2cc403c","order_by":1,"name":"Qian Wang","email":"","orcid":"","institution":"Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Qian","middleName":"","lastName":"Wang","suffix":""},{"id":761239,"identity":"cc1f883b-8c04-4da9-9494-961f028a1b6c","order_by":2,"name":"Shaoqiong Zhou","email":"","orcid":"","institution":"Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Shaoqiong","middleName":"","lastName":"Zhou","suffix":""},{"id":761240,"identity":"c16c986b-a273-40d4-a85e-f680c2488a4d","order_by":3,"name":"Bin Wang","email":"","orcid":"","institution":"Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Bin","middleName":"","lastName":"Wang","suffix":""},{"id":761241,"identity":"c65c42f9-8e3d-42ef-80e7-7dbc27bd41c7","order_by":4,"name":"Li Ke","email":"","orcid":"","institution":"Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Li","middleName":"","lastName":"Ke","suffix":""},{"id":761236,"identity":"21bdec68-1cc1-4eba-b767-f75e5179b07c","order_by":5,"name":"Ping He","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0UlEQVRIiWNgGAWjYDACZjCySYDw2IjXkpYApojTAtF1mAQt5uy8h18XVJzPMzh//gDDh7LDDPyzG/BrsWzmS7OeceZ2scGNZAbGGecOM0jcOYBfi8FhHjNj3rbbiRtuMDMw87YdZjCQSCBGy79ziRvOH2Zg/kukFuPHvA0HEjccSGZgZiRGi2Uzjxkzz7HkxJk3kg0O9pxL55G4QUCLOf8Z4888NXaJfecPPnzwo8xajn8GIYcB40ICxjkAxDz41UO0MH8gqGoUjIJRMApGNgAAKKlB91ChgaIAAAAASUVORK5CYII=","orcid":"","institution":"Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Ping","middleName":"","lastName":"He","suffix":""}],"badges":[],"createdAt":"2020-07-03 00:52:41","currentVersionCode":1,"declarations":{"humanSubjects":true,"vertebrateSubjects":false,"conflictsOfInterestStatement":true,"humanSubjectEthicalGuidelines":true,"humanSubjectConsent":true,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false,"coiExplicitlySet":false},"doi":"10.21203/rs.3.rs-40006/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-40006/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.3892/etm.2021.9658","type":"published","date":"2021-01-18T19:00:49+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":1510771,"identity":"70214250-0b40-438c-93a3-428a0ab4d6f9","added_by":"auto","created_at":"2020-07-07 19:26:39","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":121919,"visible":true,"origin":"","legend":"Patient flowchart\n","description":"","filename":"Figure.jpg","url":"https://assets-eu.researchsquare.com/files/rs-40006/v1/Figure.jpg"},{"id":13549283,"identity":"c82c5a04-a287-422b-bb56-3babcdd3e003","added_by":"auto","created_at":"2021-09-17 02:20:32","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":389557,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-40006/v1/c9ca9d69-6493-4108-b65a-3fd3c5039c26.pdf"},{"id":1510773,"identity":"31eb10d7-7561-411e-99af-c9605683ece0","added_by":"auto","created_at":"2020-07-07 19:26:39","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":30727,"visible":true,"origin":"","legend":"","description":"","filename":"Tables.docx","url":"https://assets-eu.researchsquare.com/files/rs-40006/v1/Tables.docx"}],"financialInterests":"","formattedTitle":"\u003cp\u003eRecombinant interleukin-2 stimulates lymphocyte recovery in severe patients with COVID-19\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe corona virus disease 2019 (COVID–19), caused by severe acute respiratory syndrome coronavirus–2 (SARS-CoV–2) has spread out in the world, posing a critical threat to global health\u003ca href=\"#_bookmark0\"\u003e1\u003c/a\u003e. In the early stage of COVID–19, patients usually manifested a normal or lowering white blood cell count in peripheral blood, a remarkable decreasing of lymphocytes count and increasing of CRP. In the advanced stage of COVID–19, numerous inflammatory cytokines such as interleukins, tumor necrosis factor and chemokines were released and attacked the immune organs and tissues. That induced inflammatory storm and led to disease progression and multiple organ failure\u003ca href=\"#_bookmark1\"\u003e2\u003c/a\u003e\u003ca href=\"#_bookmark2\"\u003e,3. \u003c/a\u003eThe degree of lymphopenia and a proinflammatory cytokine storm happened more frequently in severe COVID–19 patients than in mild cases, and are associated with the disease severity\u003ca href=\"#_bookmark3\"\u003e4\u003c/a\u003e\u003c/p\u003e\n\n\u003cp\u003eRecently, it was reported that CD4+ T cells decreased remarkably in patients in the early recovery stage of COVID–19. It revealed that IL–2, IL–18, IL–4 and TNFSF13 might be beneficial for the recovery of COVID–19 patients\u003ca href=\"#_bookmark4\"\u003e5. \u003c/a\u003eHowever, the role of these cytokines might play in the therapy of COVID–19 had not known yet.\u003c/p\u003e\n\u003cp\u003eOur study applied rIL–2, an immumodulator usually used in treatment of cancer, to the therapy of COVID–19 and investigated the changes of peripheral blood white blood cells count, lymphocytes count, levels of IL–6 and CRP. Moreover, the side effect of rIL–2 was observed simultaneously. That would make a sense of the effect and safety of rIL–2 on the treatment of COVID–19.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cem\u003eStudy design and participants\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThis is a retrospective single-center case control study included 59 severe cases with COVID–19. The patients were admitted to the West campus of Union Hospital, Tongji Medical College Huazhong University of Science and Technology (Wuhan, China), from January 29, 2020 to February 29, 2020. COVID–19 was diagnosed by meeting the criteria of epidemiology and clinical syndrome, chest computerized tomography (CT) and lymphocyte manifestations and confirmed by real-time reverse transcription- polymerase chain reaction (RT-PCR) detection for routine pharyngeal swab specimens according to the New Coronavirus Pneumonia Prevention and Control Program (6th edition) published by the National Health Commission of China\u003ca href=\"#_bookmark5\"\u003e6\u003c/a\u003e. The final date of follow up was April 15, 2020. Adult severe cases were diagnosed when any of the following criteria was met: (1) Respiratory distress (≧30 breaths/ min); (2) Oxygen saturation≤93% at rest; (3) Arterial partial pressure of oxygen (PaO2)/ fraction of inspired oxygen (FiO2)≤300mmHg (lmmHg = 0.133kPa). Patients who received a one-week to 10 days subcutaneous injection of the recombinant interleulin–2 one million IU per day (rIL–2, Beijing sihuan pharmaceutical factory, production batch number 20190915) treatment during hospitalization were classified as rIL–2 group. Patients who did not receive rIL–2 during hospitalization were classified as non-rIL–2 group. Propensity score-matched cohorts were created based on variables which were expected to be potential confounders associated with exposure to rIL–2, including age, gender, fever, fatigue, cough, comorbidities (hypertension, coronary heart disease, diabetes, and cerebrovascular disease) and in-hospital medications. The rIL–2 group and non-rIL–2 group were paired at 1:1 according to the propensity scores using exact matching with a caliper size of 0.05.\u003c/p\u003e\n\u003cp\u003eWe used the following inclusion and exclusion criteria to determine the study population. The inclusion criteria was aged over 18 years severe COVID–19 patients admitted in the hospital. The exclusion criteria included incomplete medical records (e.g., transfer to any other hospital), pregnancy, not survive during hospitalization, not controlled fever, severe hepatic dysfunction and severe renal dysfunction. The study protocols were approved by the ethics committee of Union Hospital, Tongji Medical College Huazhong University of Science and Technology.\u003c/p\u003e\n\u003ch3 data-xsweet-outline-level=\"3\"\u003eData collection\u003c/h3\u003e\n\u003cp\u003eFollowing data were collected including patient demographic information, clinical characteristics, laboratory data, history of comorbidities and therapeutic interventions during the hospitalization. The patient demographic information (age and gender) and clinical characteristics (fever, cough and fatigue) were collected from electronic medical system. Laboratory data (blood cell count, IL- 6, CRP, hepatic function and renal function) were collected from laboratory information system. Comorbidities (hypertension, coronary heart disease, diabetes and cerebrovascular diseases) were extracted from medical history. The in-hospital medications and interventions were collected from doctor’s advice. Personal health identifying information (\u003cem\u003ee.g.,\u003c/em\u003e name and ID) was anonymized and each participant was given a study ID using an electronic coding system before data extraction to preserve patient privacy. Data were carefully reviewed and confirmed by experienced physicians and were double-checked to guarantee the accuracy of the data extraction procedures.\u003c/p\u003e\n\u003ch3 data-xsweet-outline-level=\"3\"\u003eStatistical analysis\u003c/h3\u003e\n\u003cp\u003eContinuous variables were expressed as median and interquartile range (IQR), and categorical variables were expressed as number and percentage (%). Statistical differences between two groups were analyzed using the Mann-Whitney test or χ2 test. A two-side α less than 0.05 was considered statistically different. Data were analyzed in SPSS Statistics (version 23.0, IBM, Armonk, NY, USA).\u003c/p\u003e"},{"header":"Results","content":"\u003ch3\u003eParticipants\u003c/h3\u003e\n\u003cp\u003eFrom January 29, 2020 to to February 29, 2020, 72 adult patients were hospitalized. After excluding five death cases, three were transferred to other hospitals, two with not controlled fever, one with severe hepatic dysfunction and two with severe renal dysfunction, a total of 59 patients were included in this study. There were 20 patients accepted rIL–2 treatment. Twenty patients were chosen and paired with the rIL–2 group from the 39 patients of non-rIL–2 group (Figure 1). The clinical data of patient demographic information and history of comorbidities were collected on admission. Symptoms, signs and laboratory data were collected before and after rIL–2 treatment in rIL–2 group and at the same time point in non-rIL–2 group. The in-hospital medications and interventions were obtained during the hospitalization. The length of hospital stay were collected at the time of patients discharged from hospital.\u003c/p\u003e\n\u003ch3 data-xsweet-outline-level=\"3\"\u003eBaseline Characteristics of the participants and between groups\u003c/h3\u003e\n\u003cp\u003eAs shown in Table 1, the median age of all patients was 56 years ( 48, 64), ranging from 23 years to 88 years, among whom 54.24% were male. Comorbidities such as hypertension (28.81%), diabetes (15.25%), coronary heart disease (6.78%) and cerebrovascular disease (10.17%) were common. The symptoms before rIL–2 intervention of fatigue (49.15%) and cough (77.97%) were observed in most patients. There were 69.49% patients with fever on admission. After treatment no patient included in the study had fever. All patients’ white blood cell counted in a median of 5.90(4.2，7.2)×109/L, neutrophil in a median of 3.98（2.8，5.1）×109/L and lymphocyte in a median of 0.980（0.8，1.4）×109/L. High serum IL–6 level with a median of 6.420 (1.5，16.2) pg/mL and high CRP with a median of 27.220 (4.7，48.2) mg/L were demonstrated. During hospitalization, 53 (89.83%) patients accepted antiviral drugs therapy, 44 (74.58%) patients accepted antibiotics drugs therapy, 5 (10.17%) patients accepted systemic corticosteroids therapy and 56 (94.92%) patients accepted traditional Chinese medicine therapy. The above clinical characteristics in both groups before and after matching did not have significant difference.\u003c/p\u003e\n\u003ch3 data-xsweet-outline-level=\"3\"\u003eComparison of laboratory results in rIL–2 group patients before and after rIL–2 treatment\u003c/h3\u003e\n\n\u003cp\u003eAn obvious rising of lymphocyte count was detected after rIL–2 plus regular treatment, which was 1.935 (1.6, 3.0)×109/L compared to 1.110 (0.9, 1.4)×109/L before rIL–2 treatment in rIL–2 group (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.01). The CRP showed a significant decreasing after rIL–2 plus regular treatment, which lowered from 21.740 (0.5, 65.1) mg/L to 3.965 (1.5, 5.7) mg/L (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.05). The WBC count were 6.215 (5.4, 7.2)×109/L and 6.935 (5.2, 8.3)×109/L before and after rIL–2 treatment in rIL–2 group, respectively. The difference was not significant (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05). The neutrophils count was 3.075 (2.2, 4.3)×109/L in rIL–2 group after rIL–2 treatment, that was similar with 3.830 (2.8, 4.9)×109/L before rIL–2 treatment (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05). The IL–6 were 7.765 (1.6, 21.7) pg/mL before rIL–2 treatment. After rIL- 2 treatment, the IL–6 decreased to 3.730 (1.5, 7.7) pg/mL. But the decreasing did not get significant difference (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05). There were no obvious difference in hemoglobin (Hb) levels, platelet (PLT) count, alanine aminotransferase (ALT) levels, aspartate aminotransferase (AST) levels, blood urea nitrogen (BUN) levels and serum creatinine (Scr) levels before and after rIL–2 treatment (130.5 [123.0, 148.8] g/L \u003cem\u003evs \u003c/em\u003e128.0 [120.3, 138.8] g/L, 165.5 [132.5, 243.0] ×109/L \u003cem\u003evs \u003c/em\u003e215.5 [117.8, 254.5] ×109/L, 43.0 [30.0, 59.5] U/L \u003cem\u003evs \u003c/em\u003e52.0 [24.8, 67.8] U/L, 29.5 [21.0, 36.8] U/L \u003cem\u003evs \u003c/em\u003e28.0 [19.0, 31.0] U/L, 4.845 [3.5, 7.4] mmol/L \u003cem\u003evs \u003c/em\u003e4.305 [3.6, 5.1] mmol/L, 69.500 [58.7, 78.7] μmol/L \u003cem\u003evs \u003c/em\u003e65.550 [54.3, 73.8]μmol/L, repectively. All \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05) (Table 2).\u003c/p\u003e\n\u003ch3 data-xsweet-outline-level=\"3\"\u003eComparison of laboratory results in non-rIL–2 group patients before and after rIL–2 treatment\u003c/h3\u003e\n\u003cp\u003eThere were a clearly visible increasing in lymphocyte count from 0.875 (0.7, 1.3)×109/L to 1.275 (1.0, 1.6)×109/L (p\u0026lt;0.01) and a decreasing in CRP level from 29.930 (7.6, 47.8) mg/L to 4.585 (2.8, 12.1) mg/L (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.05) in non rIL–2 group with regular treatment. No obvious effect was demonstrated on change in WBC count (5.070 [4.0, 7.3]×109/L \u003cem\u003evs \u003c/em\u003e6.075 [4.6, 7.7]×109/L, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05), neutrophils count (3.755 [2.5, 6.2]×109/L, 3.925 [2.8, 5.8]×109/L, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05) and serum IL–6 levels (6.070 [1.5, 15.9] pg/mL, 2.445 [1.5, 8.0] pg/mL, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05). In addition, regular treatment had no effect on Hb levels, PLT count, ALT levels, AST levels, BUN levels and Scr levels (123.500 [110.8, 139.8]g/L \u003cem\u003evs \u003c/em\u003e131.000 [102.0, 137.8]g/L, 195.500 [156.5, 270.5]×109/L \u003cem\u003evs \u003c/em\u003e217.000 [177.8, 342.8]×109/L, 25.500 [20.3, 52.3] U/L \u003cem\u003evs \u003c/em\u003e31.500 [20.0, 49.8]U/L, 34.000 [24.5, 44.5] U/L \u003cem\u003evs \u003c/em\u003e25.500 [18.3, 33.8]U/L, 4.480 [3.2, 5.5] mmol/L \u003cem\u003evs \u003c/em\u003e4.405 [3.3, 5.9] mmol/L, 61.150 [52.0, 74.8] μmol/L \u003cem\u003evs \u003c/em\u003e60.600 [53.8, 68.5]μmol/L, repectively. All \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05) (Table 2).\u003c/p\u003e\n\u003ch3 data-xsweet-outline-level=\"3\"\u003eComparison of laboratory results in rIL–2 group and non-rIL–2 group patients after rIL–2 treatment\u003c/h3\u003e\n\u003cp\u003eCompared to non-IL–2 group, rIL–2 group had a significant higher level of lymphocytes, which was 1.935 (1.6, 3.0)×109/L in rIL–2 group vs 1.275 (1.0, 1.6)×109/L in non-rIL–2 group (\u003cem\u003ep\u003c/em\u003e\u0026lt;0.01). The level of CRP did not show a significant difference between the two groups (3.965 [1.5, 5.7] mg/L in rIL–2 group vs 4.585 [2.8, 12.1] mg/L in non-rIL–2 group, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05). There were no difference in WBC count, neutrophils count and IL–6 levels between the two groups (6.935 [5.2, 8.3]×109/L \u003cem\u003evs \u003c/em\u003e6.075 [4.6, 7.7]×109/L, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05; 3.075 [2.2,4.3]×109/L \u003cem\u003evs \u003c/em\u003e3.925 [2.8, 5.8]×109/L, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05; 3.730 [1.5, 7.7] pg/mL \u003cem\u003evs \u003c/em\u003e2.445 [1.5, 8.0] pg/mL, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05, respectively). The length of hospital stay between the two groups made no difference (34.00 [20.09，47.91] days \u003cem\u003evs \u003c/em\u003e32.70 [17.07，48.33] days, \u003cem\u003ep\u003c/em\u003e\u0026gt;0.05) (Table 2).\u003c/p\u003e\n\u003ch3 data-xsweet-outline-level=\"3\"\u003eDrug associated adverse effects of rIL–2 treatment\u003c/h3\u003e\n\u003cp\u003eAfter regular treatment such as antiviral drugs, antibiotics, corticosteroids and traditional Chinese medicine, all participants were in normal temperature. In rIL–2 treatment group, 4 (20%) cases of fever associated with rIL–2 were reported with the temperature lowered than 38.5℃ for less than 4 days. The patients complained muscle soreness accompanied with fever. No patients with new fever onset was reported in non-rIL–2 group. The difference was significant (p\u0026lt;0.05). However, rIL–2 treatments did not make obvious change in Hb, PLT count, ALT, AST, BUN and Scr levels (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05) (Table 2).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eRecent studies have shown that lymphopenia was one of the typical laboratory abnormalities of COVID–19\u003ca href=\"#_bookmark3\"\u003e4–8. \u003c/a\u003eLymphopenia was observed in 44.4% (12/27) of mild patients and 84.6% (11/13) of severe patients at the onset of COVID–19. The absolute counts of lymphocytes in the peripheral blood of the severe patients was significantly decreased at the time point of disease onset and became even greater on 4–6 days later. From 7 to 15 days after disease onset, the lymphocyte counts gradually increased in the severe patients, and reached a comparable level to that of the mild patients at 16 days after disease onset. Sustained decreases in CD3+ , CD8+ and CD4+ T cell counts were also observed in the severe patients\u003ca href=\"#_bookmark3\"\u003e4\u003c/a\u003e. CD4+ T cells decreased remarkably in patients in the early recovery stage of COVID–19. T and B cell clones were highly expanded during the recovery stage in COVID–19 patients\u003ca href=\"#_bookmark4\"\u003e5. \u003c/a\u003eIncreasing data from cohort studies and clinical trials had shown that higher CD4+ T-cell counts were associated with reductions in morbidity and mortality from both AIDS and serious non-AIDS conditions, including cardiovascular disease\u003ca href=\"#_bookmark6\"\u003e9\u003c/a\u003e. All these observations revealed that it might be a prospective therapy for COVID–19 to increase lymphocytes number especially CD4+ T cells.\u003c/p\u003e\n\u003cp\u003eIn previous studies and clinical trials rIL–2 has proven an effective means to enhance the efficacy of antitumor immunotherapy\u003ca href=\"#_bookmark7\"\u003e10\u003c/a\u003e. Several studies demonstrated that rIL–2 showed an immunomodulator effect in virus infections. An \u003cem\u003ein vivo \u003c/em\u003estudy in the immunocompetent BALB/c mouse reported repeated application of rhIL–2 significantly enhanced the antiviral effect of the low initial number of lymphocytes in several tissues in prophylaxis and also in therapy\u003ca href=\"#_bookmark8\"\u003e11\u003c/a\u003e. In a prospective cohort study in patients with HIV, CD4+ T-cell counts were observed be increased after rIL–2 treatment\u003ca href=\"#_bookmark9\"\u003e12. \u003c/a\u003eLow-dose recombinant human IL–2 selectively modulated CD4(+) T cell subsets in patients with systemic lupus erythematosus and markedly reduced the activity of disease\u003ca href=\"#_bookmark10\"\u003e13.\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003eIn this study, we observed that rIL–2 could increase lymphocytes number in peripheral blood. CRP level showed a remarkable decrease after rIL–2 treatment compared with rIL–2 treatment before, but the difference between rIL–2 group and non rIL–2 group did not reach a significant point (\u003cem\u003ep\u003c/em\u003e\u0026gt;0.05). Also the clinical outcome of the length of hospital stay was observed unaffected by rIL-2. Recently it was reported that T cells produced IL–2 promoted survival, proliferation, and differentiation and antibodies production of B cells in COVID–19 patients. Consequently, B cells produce numerous SARS-COV–2- specific antibodies to clear viruses \u003ca href=\"#_bookmark4\"\u003e5\u003c/a\u003e\u003ca href=\"#_bookmark11\"\u003e,14. \u003c/a\u003eAdditional supplying of rIL–2 to COVID–19 patients stimulated lymphocyes recovery might have potential therapeutic effect including: First, the rising of lymphocytes might be associated with the changes of T cell subsets especially the rising of CD4+ T cells. Second, rIL–2 might mimick the effect of native IL- 2 and stimulate survival, proliferation, and differentiation and antibodies production of B cells, which accelerated the clearance of virus. Third, rIL–2 might relieve inflammation storm by decreasing the levels of cytokines. The precise mechanisms still required more data to be elucidated. The rIL–2 was tolerated in the severe COVID–19 patients. Only four adverse events were reported in rIL–2 group. The adverse reactions were fever (lower than 38.5℃) and muscle soreness. All adverse events reported were mild, transient and totally relieved after stopping rIL–2 treatment.\u003c/p\u003e\n\n\u003cp\u003eAdditionally, no abnormal changes in laboratory measurements were clinically significant or considered to be related to rIL–2. For the dose of rIL–2 used in this study was ultra-low (≤1 million IU /day), the adverse reaction of venous thromboembolism detected by ultrasound had not been obtained.\u003c/p\u003e\n\u003cp\u003eThere are some limitations in the present study. It was a retrospective single-center case control study. The hospital was assigned by government to accept mostly severe and critical COVID–19 patients. Only severe COVID–19 patients were included in this study. These might cause some selective bias. The results of this study are limited by the small size of the cohort and the short duration of rIL–2 treatment. Also the effect of different dosage of rIL–2 impacted on different stage of COVID–19 had not been observed.\u003c/p\u003e\n\u003cp\u003eIn conclusion, rIL–2 might be used as a prospective therapy in severe COVID–19 patients for it might potentially improve the recovery of disease by increasing lymphocytes number.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eThe participators/patients reported in our paper consented to participate and/or publish. We thank all participators/patients involved in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePH and MEZ designed study, performed statistical analysis and wrote manuscript. MEZ, QW，BW，SQZ and LK collected data. All authors have approved the final version of this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe acknowledge all health-care workers from Beijing, Hainan and Anhui medical teams involved in the diagnosis and treatment of patients in the Union Hospital, Tongji Medical College Huazhong University of Science and Technology.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSources of funding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDisclosures \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eWHO. Situation Report-68.\u003c/li\u003e\n\u003cli\u003eShimabukuro-Vornhagen, et al. Cytokine release syndrome. J Immunother Cancer \u003cstrong\u003e6\u003c/strong\u003e, 56, doi:10.1186/s40425-018-0343-910.1186/s40425-018-0343-9 [pii] (2018).\u003c/li\u003e\n\u003cli\u003eHuang, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet \u003cstrong\u003e395\u003c/strong\u003e, 497-506, doi:S0140-6736(20)30183-5 [pii]10.1016/S0140-6736(20)30183-5 (2020).\u003c/li\u003e\n\u003cli\u003eLiu, et al. Longitudinal characteristics of lymphocyte responses and cytokine profiles in the peripheral blood of SARS-CoV-2 infected patients. EBioMedicine \u003cstrong\u003e55\u003c/strong\u003e, 102763, doi:S2352- 3964(20)30138-9 [pii]10.1016/j.ebiom.2020.102763 (2020).\u003c/li\u003e\n\u003cli\u003eWen, et al. Immune cell profiling of COVID-19 patients in the recovery stage by single- cell sequencing. Cell Discov \u003cstrong\u003e6\u003c/strong\u003e, 31, doi:10.1038/s41421-020-0168-9 168 [pii] (2020).\u003c/li\u003e\n\u003cli\u003eWang, et al. Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus-Infected Pneumonia in Wuhan, China. JAMA, doi:10.1001/jama.2020.1585 2761044 [pii] (2020).\u003c/li\u003e\n\u003cli\u003eChen, et al. Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet \u003cstrong\u003e395\u003c/strong\u003e, 507-513, doi:S0140-6736(20)30211-7 [pii] 10.1016/S0140-6736(20)30211-7 (2020).\u003c/li\u003e\n\u003cli\u003eChen, et al. Clinical and immunological features of severe and moderate coronavirus disease 2019. J Clin Invest \u003cstrong\u003e130\u003c/strong\u003e, 2620-2629, doi:10.1172/JCI137244 137244 [pii] (2020).\u003c/li\u003e\n\u003cli\u003ePett, L., Kelleher, A. D. \u0026amp; Emery, S. Role of interleukin-2 in patients with HIV infection. Drugs \u003cstrong\u003e70\u003c/strong\u003e, 1115-1130, doi:10.2165/10898620-000000000-00000 3 [pii] (2010).\u003c/li\u003e\n\u003cli\u003eMahmoudpour, H. et al. Safety of low-dose subcutaneous recombinant interleukin-2: systematic review and meta-analysis of randomized controlled trials. Sci Rep \u003cstrong\u003e9\u003c/strong\u003e, 7145, doi:10.1038/s41598-019-43530-x 10.1038/s41598-019-43530-x [pii] (2019).\u003c/li\u003e\n\u003cli\u003eReddehase, J., Mutter, W. \u0026amp; Koszinowski, U. H. In vivo application of recombinant interleukin 2 in the immunotherapy of established cytomegalovirus infection. J Exp Med \u003cstrong\u003e165\u003c/strong\u003e, 650-656, doi:10.1084/jem.165.3.650 (1987).\u003c/li\u003e\n\u003cli\u003eCrespo, et al. Efficacy of recombinant interleukin-2 (rIL-2) in patients with advanced HIV- 1 infection and blunted immune response to HAART. Enferm Infecc Microbiol Clin \u003cstrong\u003e26\u003c/strong\u003e, 27- 31, doi:S0213-005X(08)72648-X [pii] 10.1157/13114392 (2008).\u003c/li\u003e\n\u003cli\u003eHe, et al. Low-dose interleukin-2 treatment selectively modulates CD4(+) T cell subsets in patients with systemic lupus erythematosus. Nat Med \u003cstrong\u003e22\u003c/strong\u003e, 991-993, doi:10.1038/nm.4148 nm.4148 [pii] (2016).\u003c/li\u003e\n\u003cli\u003eZhou, et al. Aberrant epigenetic and genetic marks are seen in myelodysplastic leukocytes and reveal Dock4 as a candidate pathogenic gene on chromosome 7q. J Biol Chem \u003cstrong\u003e286\u003c/strong\u003e, 25211-25223, doi:10.1074/jbc.M111.235028 M111.235028 [pii] (2011).\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eDue to technical limitations, Tables 1-2 are provided in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":" COVID-19, recombinant human interleukin-2, lymphopenia, cytokine, C-reactive protein ","lastPublishedDoi":"10.21203/rs.3.rs-40006/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-40006/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObject: \u003c/strong\u003eA recently developing pneumonia called COVID-19 which caused by SARS-CoV-2 has quickly spread across the world. Lymphopenia and a proinflammatory cytokine storm frequently happened in severe COVID-19 patients. But no specific immunomodulate therapy on COVID-19 had been reported. In this retrospect case control study, we observed the potential therapeutic effect of recombinant human interleukin-2 (rIL-2) on severe COVID-19 patients in a hospital in Wuhan, China. \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e Fifty nine severe cases with COVID-19 admitted in hospital from January 29, 2020 to February 29, 2020 were included in this study. Twenty patients received a one-week to 10 days subcutaneous injection of the recombinant human interleulin-2 1 million IU per day other than regular treatment were classified as rIL-2 group. Twenty from thirty nine patients with regular treatment without intervention of rIL-2 were matched as the control group. Clinical characteristic such as age, gender, symptoms, signs, laboratory data and comorbidities were paired in these two groups. Changes of lymphocytes counts, IL-6 and C- reactive protein (CRP) before and after rIL-2 treatment and differences between rIL-2 group and non-rIL-2 group were analyzed.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e There were a clearly visible increasing in lymphocyte counts and a decreasing in CRP level in non rIL-2 group and rIL-2 group. The difference of the change of lymphocyte counts were significant in rIL-2 group and non-rIL-2 group (p\u0026lt;0.01). Though CRP decreased more in rIL-2 group, it did not show a significant difference between the two groups (p\u0026gt;0.05).\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e RIL-2 might be a prospective adjuvant therapy for severe COVID-19 patients by increasing lymphocytes number. \u003c/p\u003e","manuscriptTitle":"Recombinant interleukin-2 stimulates lymphocyte recovery in severe patients with COVID-19","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2020-07-07 19:26:38","doi":"10.21203/rs.3.rs-40006/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"389268bb-046e-4056-a312-cfc7f172b463","owner":[],"postedDate":"July 7th, 2020","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":140705,"name":"Immunology"},{"id":140706,"name":"Epidemiology"},{"id":140707,"name":"Clinical Pharmacology"}],"tags":[],"updatedAt":"2021-07-22T19:00:49+00:00","versionOfRecord":{"articleIdentity":"rs-40006","link":"https://doi.org/10.3892/etm.2021.9658","journal":{"identity":"experimental-and-therapeutic-medicine","isVorOnly":true,"title":"Experimental and Therapeutic Medicine"},"publishedOn":"2021-01-18 19:00:49","publishedOnDateReadable":"January 18th, 2021"},"versionCreatedAt":"2020-07-07 19:26:38","video":"","vorDoi":"10.3892/etm.2021.9658","vorDoiUrl":"https://doi.org/10.3892/etm.2021.9658","workflowStages":[]},"version":"v1","identity":"rs-40006","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-40006","identity":"rs-40006","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}