{"paper_id":"39258df5-4331-438e-ab09-a69efff8ed6a","body_text":"Therapeutic use of mesenchymal stem cells may be a means of transmitting leishmaniasis in dogs | 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 Case Report Therapeutic use of mesenchymal stem cells may be a means of transmitting leishmaniasis in dogs Vitor Pegorer Bilharinho, Malú Mateus Santos Obata, Joely Ferreira Figueiredo Bittar, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4591915/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The aim of this case report is to record the finding of leishmaniasis-causing parasites in mesenchymal stem cells from dogs from a non-endemic area, which were negative when submitted to the RIFI and ELISA tests, a fact that had not been documented until now. This demonstrates that this widely distributed and lethal zoonosis can escape traditional means of diagnosis and that stem cell therapy has the potential to be a source of transmission of the disease. Although the relative safety of stem cell therapy is presumed, the possible risks associated with its use, especially the risk of parasite transmission, cannot be ignored. It is therefore essential to develop rigorous screening and testing protocols to ensure the safety of stem cell therapy. Leishmaniasis 1 Cellular therapy 2 Zoonosis3 Figures Figure 1 Introduction Leishmaniasis is one of the neglected tropical diseases of greatest medical and veterinary importance and is a public health problem in several countries [ 1 , 2 ]. According to data published by the World Health Organization, 94% of new cases have occurred in seven countries: Brazil, Ethiopia, India, Kenya, Somalia, South Sudan and Sudan. These countries share problems such as frequent epidemics, humans and ani-mals acting as reservoirs and the presence of the transmitting flies [ 3 ]. The disease is transmitted through the bite of sand flies of the genera Phlebotomus and Lutzomyia. It can manifest itself in cutaneous or visceral form, depending on which cell type is infected and if left untreated, the mortality rate in developing countries can reach 100% in 2 years [ 2 , 3 ]. Mesenchymal stem cells (MSCs) are multipotent cells that can be isolated from different tissues such as bone marrow [ 4 ], umbilical cord, adipose tissue [ 5 ], peripheral blood, tooth root and liver [ 6 ]. Stem cell therapy has emerged as a promising approach for treating a wide range of diseases and injuries [ 7 , 8 ]. Stem cells have the ability to differentiate into various types of cells and can be used to replace or repair damaged tissue [ 9 ]. However, the safety of stem cell therapy has been a major concern due to the possible risks associated with its use, including the possibility of introducing parasites into the host [ 10 ]. Stem cells have recently been shown to function as a protective niche for pathogens, such as Mycobacterium tuberculosis [ 11 ]. Studies suggest that these cells protect intracellular pathogens from the action of the immune system and from the action of drugs, as they reside in immunoprivileged sites in the bone marrow and mesenchymal stem cells do not trigger effector functions of cytotoxic T lymphocytes as they do not have major histocompatibility complex (MHC) II and their MHC I molecules are functionally inactive [ 12 , 13 , 14 ]. Leishmania has developed survival mechanisms such as modulating the activities of macrophage phagolysosomes [ 15 ], neutrophils, increasing their lifespan in tis-sues and delaying their apoptosis, thus benefiting the multiplication of Leishmania, and even the mechanism known as the \"trojan horse\" [ 16 ]. In vitro studies have reported the infection of mesenchymal stem cells by different species of Leishmania, which may suggest a mechanism used by Leishmania to evade the immune system, present asymptomatic patients, and reactivate the disease [ 17 ]. Studies have shown that Leishmania parasites are capable of infecting bone mar-row-derived mesenchymal stem cells and altering their differentiation potential, leading to the development of an immunosuppressive microenvironment that supports the parasite's survival [ 18 , 19 ]. Another study reported the presence of Leishmania parasites in umbilical cord derived MSCs, suggesting that the parasites may be present in the stem cell preparation itself [ 20 ]. The main objective of this case report is to document the unprecedented accidental isolation of amastigote forms of Leishmania in mesenchymal stem cell cultures from dogs from a region not endemic for the disease. It is noteworthy that this is the first report of its kind in the world, and its purpose is to raise awareness of the need to establish strict selection and screening criteria for stem cell donors. Materials and Methods Three healthy male dogs of no defined breed, two years old and with an average body mass of 18 ± 2 kg, were received at the Small Animal Experimentation Center of the Universidade Federal de Minas Gerais (UFMG) Veterinary School. The dogs were not client owned; they had been made available by the research institution to be used in another high-level study. The animals underwent a clinical examination and blood samples were taken for a blood count and serology to diagnose Leishmaniasis using the Enzyme Linked Immunosorbent Assay (ELISA) and Indirect Immunofluorescence (RIFI) methods. No changes were observed in the clinical examinations or in the blood count, and the ELISA and RIFI results were negative for all three animals. The following week, the dogs underwent adipose tissue biopsy to isolate and culture mesenchymal stem cells. The right gluteal region was trichotomized and prepared for aseptic surgery. The cephalic vein was catheterized, and the animals were given propofol (Fresofol, Fresenius Kabi, Brazil) 3mg/kg, intra-venous (IV) for intubation and anesthetic maintenance. As an analgesic and anti-inflammatory, meloxicam (Maxicam, Ouro Fino, Brazil) 0.2mg/kg, intramuscular (IM) was administered immediately after induction of anesthesia. The adipose tissue samples were taken surgically from the subcutaneous gluteal region just above the greater trochanter. Approximately 1cm3 of adipose tissue was taken from each animal, totaling 3cm3 of final sample. Immediately after collection, the adipose tissue samples were sent to the Stem Cell Center of the UFMG Veterinary School for isolation and cultivation of Mesenchymal Stem Cells (MSCs) according to the established protocol described below [ 9 ]. The adipose tissue samples were washed with 0.15 molar phosphate-buffered saline (PBS) and subjected to a digestion protocol using a 0.1% mass/volume (M/V) collagenase B solution (Roche Applied Science, Ger-many). After processing, the stromal fraction was cultured in T75 bottles kept in an oven at 37 Cº and 5% CO2 with DMEM (Gibco, USA), enriched with gentamicin (60 µg/L), penicillin 100 UI/mL, streptomycin 100 µg/mL, amphotericin 25 µg/mL (PSA, Sigma-Aldrich, USA) and 10% fetal bovine serum (Sorali, Brazil). The culture medium was changed every 4 days and when cell confluence reached 80–90%, the cells were repotted into other T75 bottles. In the fourth passage, the cells were subjected to phenotypic characterization by flow cytometry to assess the expression of CD90, CD29, CD45 and CD34. Low expression of hematopoietic cell markers CD45 (1.54%) and CD34 (0.88%) and high expression of stem cell markers CD90 (60.94%) and CD29 (77.08%) were observed. For morphological assessment, the cells were plated at a density of 1x104 cells/cm2 in six-well plates (Techno Plastic Products in Trasadingen, Ge-many) containing sterile coverslips (Coverslips, Sarstedt, USA). After seven days of culture at 37o C and 5% CO2, the coverslips containing the MSC were fixed with 70% alcohol, stained with hematoxylin and eosin, and evaluated under light microscopy. Results Unexpectedly, amastigote forms of Leishmania were observed inside the cells (Fig. 1). All the cells were discarded, and the three dogs were retested by RIFI and ELIZA and this time two animals were positive in both tests, and one was negative. The animals were also positive in the parasitological examination of the bone marrow. The two positive dogs were euthanized with an anesthetic overdose (Thiopental sodium 100 mg/Kg IV) followed by the application of potassium chloride (Potassium chloride solution 19.1% 20 ml IV). Discussion This is the first documented report worldwide of the accidental isolation of Leish-mania in dog mesenchymal stem cell (MSC) cultures. This unprecedented finding highlights the urgent need to establish rigorous standards in the selection of MSC donors. Once inoculated into the host, Leishmania invades any cell of the mononuclear phago-cytic system [ 21 ]. However, other cells have already been reported to be susceptible to Leishmania, such as amniotic epithelial cells, fibroblasts [ 22 ], hepatocytes [ 23 ] and mesenchymal stem cells derived from adipose tissue [ 17 ]. The findings of this report highlight the limitations of laboratory tests for detecting leishmaniasis in dogs, especially recent infections. The use of serological tests such as indirect immunofluorescence (IFI) and enzyme-linked immunosorbent assay (ELI-SA) was not effective in detecting Leishmania in the animals in this report. Although these tests are recommended by the Ministério da Agricultura, Pecuária e Abastecimento - MAPA (the Brazilian regulatory body) as screening tests, they were probably carried out at a time when the animals had not yet seroconverted. It is expected that during canine visceral leishmaniasis (CVL), symptomatic dogs and those with high parasitism are associated with an increase in immunoglobulins IgG, IgG2, IgM, IgA and IgE, while asymptomatic dogs and those with low parasitism are associated with an increase in IgG1 [ 24 ]. The chronic course of the disease, the delay in seroconversion, cross-reactions in the tests are all known mechanisms that hinder diagnosis and can result in the disease being detected several weeks after infection [ 24 , 25 ]. The parasitological method is highly specific and the identification of just one amastigote form is enough to determine the test as positive. The serological diagnostic methods of enzyme-linked immunosorbent assay and indirect immunofluorescence reaction are recommended by the MAPA, but they can cross-react and do not differentiate between current and past infections. Even so, the dogs in the study were able to evade these diagnostic methods at the time of the first test. Currently, PCR-based techniques are the main diagnostic approach due to their high sensitivity, as well as allowing the assessment of the parasite load and the identification of the Leishmania species [ 26 ]. As an alternative to improve the chances of identifying a dog infected with Leishmania, the MAPA highlights the use of Polymerase Chain Reaction (PCR) tests. PCR is a molecular technique capable of detecting Leishmania DNA in blood or tissue samples, providing higher specificity and confirming the infection. Additionally, the culture of Leishmania from tissue samples, such as bone marrow or skin, can also be performed to validate the presence of the infection. Biopsies of affected tissues, such as the skin, can be taken to confirm the presence of the parasite. However, there are indications that for more effective screening there are tests that can detect parasite infection earlier, such as ELISAp (ELISA with promastigote-coated plates) and especially Western blotting [ 25 ]. One of the main challenges of stem cell therapy is ensuring its safety. Although stem cells have shown remarkable therapeutic potential in pre-clinical studies, their use in humans remains largely experimental. Concerns about the safety of stem cell therapy include the risk of tumorigenesis, immunogenicity, and the possibility of transmission of infectious diseases, including parasites. These risks are particularly relevant in the context of allogeneic stem cell transplantation, in which stem cells from a donor are used to treat a patient [ 27 ]. Stem cell therapy is gaining popularity as a possible treatment for various conditions in dogs, including osteoarthritis, autoimmune diseases, and spinal cord injuries [ 8 , 10 , 28 , 29 ]. The use of autologous mesenchymal stem cells (MSCs) has been shown to be safe and effective in reducing pain and inflammation, improving mobility and quality of life, and promoting tissue repair in dogs [ 28 ]. However, stem cell therapy is not without its risks. One potential risk is the development of tumors or other adverse effects resulting from the uncontrolled growth or differentiation of transplanted cells [ 29 ]. Another risk is the possible transmission of infectious diseases, including viruses and bacteria, using contaminated stem cell preparations [ 17 ]. The application of amphotericin cannot be considered a limitation of the study because even though the drug has a known anti-leishmanial effect, the dose used is considered lethal to only 50% of the Leishmania. spp parasites [ 30 ], so it was not able to eliminate all the parasites of the species in the samples. Despite the risks, the use of stem cells in veterinary medicine has intensified and in some places is even available to the public. Examples include the Animal Medical Center in New York City, USA, which offers stem cell therapy for a variety of diseases in dogs and cats, including osteoarthritis, intervertebral disc disease and chronic kid-ney disease; the Veterinary Specialty Hospital of the Carolinas in North Carolina, USA and the Veterinary Regenerative Medicine Center in Ontario, Canada. This study has limitations such as the lack of identification of the species of Leishmania that was isolated along with the mesenchymal stem cells, as well as the absence of more comprehensive details about the parasite. In retrospect, it is crucial to point out that this incident occurred unexpectedly during a previous study. At the time, we were so frustrated that all the material was discarded. It was only many years later that we realized the importance of what we had, when it was no longer possible to carry out additional tests to identify more in-depth details about the parasite. Conclusion The finding of amastigote forms of Leishmania in these dogs again raises questions about the presumed safety of stem cell therapy. Therefore, there is an urgent need to develop standardized protocols for the characterization and quality control of stem cells used in clinical practice, as well as to establish clear guidelines for conducting clinical studies that evaluate the safety and efficacy of stem cell therapy. These efforts will be key to ensuring that stem cell therapy can be used safely and effectively to improve the lives of patients with various diseases and injuries. Declarations Funding: No external funding received. Conflict of interest/Competing interests: The authors declare that they have no conflict of interest, are scholars of stem cell therapy and are in favor of its clinical use if it is judicious and within what the legislation allows. Ethics approval and consent to participate: The findings of this work were observed during the conduct of the study: CAMARA, B.O.S.; OCARINO, N.M.; BERTASSOLI, B.M.; MALM, C.; ARAÚJO, F.R.; REIS, A.M.S.; JORGE, E.C.; ALVES, E.G.L.; SERAKIDES, R. Differentiation of canine adipose mesenchymal stem cells into insulin-producing cells: comparison of different culture medium compositions. DOMESTIC ANIMAL ENDOCRINOLOGY, v. 74, p. 106572, 2021. All experimental protocols were approved by the licensing/ ethics committee of the following brasilian institutions Fundação de Amparo à Pesquisa de Minas Gerais (Fapemig), Conselho Nacional de Desenvolvimento Científico e Tecnológico, and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. The study was also screened by Núcleo de Células Tronco e Terapia Celular Animal (NCT-TCA) da Escola de Veterinária da Universidade Federal de Minas Gerais, Universidade de Uberaba (UNIUBE) and Laboratório de Biologia Oral e do Desenvolvimento, Departamento de Morfologia do Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais. The methods were carried out in accordance with the relevant guidelines and regulations and can be verified in the study mentioned above. The dogs were not client owned; they had been made available by the research institution to be used in another high-level study. Consent for publication: All authors have read and agreed to the published version of the manuscript. Data Availability Statement: Data sharing not applicable to this article as no datasets were generated or analyzed during the current study. However, it is important to note that the aim of this article is to register an undocumented accidental finding which occurred while conducting another work was being conducted. The findings of this work were observed during the conduct of the study: CAMARA, B.O.S.; OCARINO, N.M.; BERTASSOLI, B.M.; MALM, C. ; ARAÚJO, F.R. ; REIS, A.M.S. ; JORGE, E.C. ; ALVES, E.G.L. ; SERAKIDES, R. . Differentiation of canine adipose mesenchymal stem cells into insulin-producing cells: comparison of different culture medium compositions. DOMESTIC ANIMAL ENDOCRINOLOGY, v. 74, p. 106572, 2021. Available at https://www.sciencedirect.com/science/article/abs/pii/S0739724020301399?via%3Dihub Materials availability: Not applicable Code availability: Not applicable Author contribution: All authors contributed equally to all parts of the project. Author Contributions: All authors contributed equally to all parts of the project. All authors have read and agreed to the published version of the manuscript. Acknowledgements. The authors would like to thank the University of Uberaba and the Stem Cell and Animal Cell Therapy Center, NCT-TCA, Department of Clinic and Surgery, Veterinary School, Federal University of Minas Gerais, for providing the physical structure and resources to carry out the study. References Alvar, J.; Vélez, I. D.; Bern, C.; Herrero, M.; Desjeux, P.; Cano, J.; Jannin, J.; den Boer, M.; WHO Leishmaniasis Control Team. Leishmaniasis worldwide and global estimates of its incidence . PloS One 2012, 7 (5), e35671. https://doi.org/10.1371/journal.pone.0035671 . Steverding, D. The history of leishmaniasis . Parasites & Vectors 2017, 10 (1), 82. https://doi.org/10.1186/s13071-017-2028-5 .. WHO: WORLD HEALTH ORGANIZATION; Global leishmaniasis surveillance, 2022: assessing trends over the past 10 years. Available at: https://www.who.int/publications/i/item/who-wer9840-471-487 . Alves, E. G.; Serakides, R.; Boeloni, J. N.; Rosado, I. R.; Ocarino, N. M.; Oliveira, H. 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Effect of adipose-derived mesenchymal stem and regenerative cells on lameness in dogs with chronic osteoarthritis of the coxofemoral joints: a randomized, double-blinded, multicenter, controlled trial . Veterinary Therapeutics: Research in Applied Veterinary Medicine 2007, 8 (4), 272–284. Rinaldi, F.; Perlingeiro, R. C. Stem cells for skeletal muscle regeneration: therapeutic potential and roadblocks . Translational Research: The Journal of Laboratory and Clinical Medicine 2014, 163 (4), 409–417. https://doi.org/10.1016/j.trsl.2013.11.006 . Soltani, S.; et al. Evaluation of Antileishmanial Activity Employing Conventional and Solid Lipid Nanoparticles of Amphotericin B on Leishmania major In Vitro and In Vivo. Infectious Disorders - Drug Targets [s.d.], 20 (6), 822–827. https://dx.doi.org/10.2174/1871526519666191015170627 Additional Declarations No competing interests reported. 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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-4591915\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":true,\"archivedVersions\":[],\"articleType\":\"Case Report\",\"associatedPublications\":[],\"authors\":[{\"id\":330046994,\"identity\":\"938da6f1-4584-4477-97b8-b6d85945eaec\",\"order_by\":0,\"name\":\"Vitor Pegorer Bilharinho\",\"email\":\"data:image/png;base64,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\",\"orcid\":\"\",\"institution\":\"Universidade de Uberaba – UNIUBE\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Vitor\",\"middleName\":\"Pegorer\",\"lastName\":\"Bilharinho\",\"suffix\":\"\"},{\"id\":330046995,\"identity\":\"17199643-0345-4d1e-9157-965fb5446d51\",\"order_by\":1,\"name\":\"Malú Mateus Santos Obata\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Universidade de Uberaba – UNIUBE\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Malú\",\"middleName\":\"Mateus Santos\",\"lastName\":\"Obata\",\"suffix\":\"\"},{\"id\":330046996,\"identity\":\"6817e138-b5af-471f-a194-26f05d1bd403\",\"order_by\":2,\"name\":\"Joely Ferreira Figueiredo Bittar\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Universidade de Uberaba – UNIUBE\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Joely\",\"middleName\":\"Ferreira Figueiredo\",\"lastName\":\"Bittar\",\"suffix\":\"\"},{\"id\":330046997,\"identity\":\"38053e42-0450-4837-ba88-3a5140a44a28\",\"order_by\":3,\"name\":\"Isabel Rodrigues Rosado\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Universidade de Uberaba – UNIUBE\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Isabel\",\"middleName\":\"Rodrigues\",\"lastName\":\"Rosado\",\"suffix\":\"\"},{\"id\":330046998,\"identity\":\"5be0c4d6-b7d8-4145-b9d5-1d458b8e74a0\",\"order_by\":4,\"name\":\"Rogéria Serakides\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"NCT-TCA, Escola de veterinária da Universidade Federal de Minas Gerais\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Rogéria\",\"middleName\":\"\",\"lastName\":\"Serakides\",\"suffix\":\"\"},{\"id\":330046999,\"identity\":\"287ecf0b-ce52-4fff-a926-43c97dcc6ed4\",\"order_by\":5,\"name\":\"Endrigo Gabellini Leonel Alves\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Universidade de Uberaba – UNIUBE\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Endrigo\",\"middleName\":\"Gabellini Leonel\",\"lastName\":\"Alves\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2024-06-17 05:30:36\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-4591915/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-4591915/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":60930518,\"identity\":\"f356e459-fba8-45dc-b06a-92138210e5ef\",\"added_by\":\"auto\",\"created_at\":\"2024-07-23 16:59:57\",\"extension\":\"jpeg\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":178302,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003ePhotomicrograph of adipose-derived mesenchymal stem cells from dogs infected with Leishmania spp. Note the cells' cytoplasm filled with amastigotes. Images \\\"A and B\\\" Hematoxylin-Eosin (H\\u0026amp;E) staining, 40x 60x objective.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"floatimage114.jpeg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-4591915/v1/f35486e61aea229db3c68fec.jpeg\"},{\"id\":62918651,\"identity\":\"0ea76050-f8f3-40fa-afac-44dc68c0d3d1\",\"added_by\":\"auto\",\"created_at\":\"2024-08-21 04:59:34\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":475590,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-4591915/v1/f2422cdf-8400-48df-931c-ffc43018c698.pdf\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"Therapeutic use of mesenchymal stem cells may be a means of transmitting leishmaniasis in dogs\",\"fulltext\":[{\"header\":\"Introduction\",\"content\":\"\\u003cp\\u003eLeishmaniasis is one of the neglected tropical diseases of greatest medical and veterinary importance and is a public health problem in several countries [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e]. According to data published by the World Health Organization, 94% of new cases have occurred in seven countries: Brazil, Ethiopia, India, Kenya, Somalia, South Sudan and Sudan. These countries share problems such as frequent epidemics, humans and ani-mals acting as reservoirs and the presence of the transmitting flies [\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eThe disease is transmitted through the bite of sand flies of the genera Phlebotomus and Lutzomyia. It can manifest itself in cutaneous or visceral form, depending on which cell type is infected and if left untreated, the mortality rate in developing countries can reach 100% in 2 years [\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eMesenchymal stem cells (MSCs) are multipotent cells that can be isolated from different tissues such as bone marrow [\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e], umbilical cord, adipose tissue [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e], peripheral blood, tooth root and liver [\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e]. Stem cell therapy has emerged as a promising approach for treating a wide range of diseases and injuries [\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e]. Stem cells have the ability to differentiate into various types of cells and can be used to replace or repair damaged tissue [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e]. However, the safety of stem cell therapy has been a major concern due to the possible risks associated with its use, including the possibility of introducing parasites into the host [\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eStem cells have recently been shown to function as a protective niche for pathogens, such as Mycobacterium tuberculosis [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e]. Studies suggest that these cells protect intracellular pathogens from the action of the immune system and from the action of drugs, as they reside in immunoprivileged sites in the bone marrow and mesenchymal stem cells do not trigger effector functions of cytotoxic T lymphocytes as they do not have major histocompatibility complex (MHC) II and their MHC I molecules are functionally inactive [\\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eLeishmania has developed survival mechanisms such as modulating the activities of macrophage phagolysosomes [\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e], neutrophils, increasing their lifespan in tis-sues and delaying their apoptosis, thus benefiting the multiplication of Leishmania, and even the mechanism known as the \\\"trojan horse\\\" [\\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e]. In vitro studies have reported the infection of mesenchymal stem cells by different species of Leishmania, which may suggest a mechanism used by Leishmania to evade the immune system, present asymptomatic patients, and reactivate the disease [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eStudies have shown that Leishmania parasites are capable of infecting bone mar-row-derived mesenchymal stem cells and altering their differentiation potential, leading to the development of an immunosuppressive microenvironment that supports the parasite's survival [\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e]. Another study reported the presence of Leishmania parasites in umbilical cord derived MSCs, suggesting that the parasites may be present in the stem cell preparation itself [\\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eThe main objective of this case report is to document the unprecedented accidental isolation of amastigote forms of Leishmania in mesenchymal stem cell cultures from dogs from a region not endemic for the disease. It is noteworthy that this is the first report of its kind in the world, and its purpose is to raise awareness of the need to establish strict selection and screening criteria for stem cell donors.\\u003c/p\\u003e\"},{\"header\":\"Materials and Methods\",\"content\":\" \\u003cp\\u003eThree healthy male dogs of no defined breed, two years old and with an average body mass of 18\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2 kg, were received at the Small Animal Experimentation Center of the Universidade Federal de Minas Gerais (UFMG) Veterinary School. The dogs were not client owned; they had been made available by the research institution to be used in another high-level study. The animals underwent a clinical examination and blood samples were taken for a blood count and serology to diagnose Leishmaniasis using the Enzyme Linked Immunosorbent Assay (ELISA) and Indirect Immunofluorescence (RIFI) methods. No changes were observed in the clinical examinations or in the blood count, and the ELISA and RIFI results were negative for all three animals. The following week, the dogs underwent adipose tissue biopsy to isolate and culture mesenchymal stem cells. The right gluteal region was trichotomized and prepared for aseptic surgery. The cephalic vein was catheterized, and the animals were given propofol (Fresofol, Fresenius Kabi, Brazil) 3mg/kg, intra-venous (IV) for intubation and anesthetic maintenance. As an analgesic and anti-inflammatory, meloxicam (Maxicam, Ouro Fino, Brazil) 0.2mg/kg, intramuscular (IM) was administered immediately after induction of anesthesia.\\u003c/p\\u003e \\u003cp\\u003eThe adipose tissue samples were taken surgically from the subcutaneous gluteal region just above the greater trochanter. Approximately 1cm3 of adipose tissue was taken from each animal, totaling 3cm3 of final sample. Immediately after collection, the adipose tissue samples were sent to the Stem Cell Center of the UFMG Veterinary School for isolation and cultivation of Mesenchymal Stem Cells (MSCs) according to the established protocol described below [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e]. The adipose tissue samples were washed with 0.15 molar phosphate-buffered saline (PBS) and subjected to a digestion protocol using a 0.1% mass/volume (M/V) collagenase B solution (Roche Applied Science, Ger-many). After processing, the stromal fraction was cultured in T75 bottles kept in an oven at 37 C\\u0026ordm; and 5% CO2 with DMEM (Gibco, USA), enriched with gentamicin (60 \\u0026micro;g/L), penicillin 100 UI/mL, streptomycin 100 \\u0026micro;g/mL, amphotericin 25 \\u0026micro;g/mL (PSA, Sigma-Aldrich, USA) and 10% fetal bovine serum (Sorali, Brazil). The culture medium was changed every 4 days and when cell confluence reached 80\\u0026ndash;90%, the cells were repotted into other T75 bottles. In the fourth passage, the cells were subjected to phenotypic characterization by flow cytometry to assess the expression of CD90, CD29, CD45 and CD34. Low expression of hematopoietic cell markers CD45 (1.54%) and CD34 (0.88%) and high expression of stem cell markers CD90 (60.94%) and CD29 (77.08%) were observed. For morphological assessment, the cells were plated at a density of 1x104 cells/cm2 in six-well plates (Techno Plastic Products in Trasadingen, Ge-many) containing sterile coverslips (Coverslips, Sarstedt, USA). After seven days of culture at 37o C and 5% CO2, the coverslips containing the MSC were fixed with 70% alcohol, stained with hematoxylin and eosin, and evaluated under light microscopy.\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"Results\",\"content\":\" \\u003cp\\u003eUnexpectedly, amastigote forms of Leishmania were observed inside the cells (Fig.\\u0026nbsp;1). All the cells were discarded, and the three dogs were retested by RIFI and ELIZA and this time two animals were positive in both tests, and one was negative. The animals were also positive in the parasitological examination of the bone marrow. The two positive dogs were euthanized with an anesthetic overdose (Thiopental sodium 100 mg/Kg IV) followed by the application of potassium chloride (Potassium chloride solution 19.1% 20 ml IV).\\u003c/p\\u003e \"},{\"header\":\"Discussion\",\"content\":\" \\u003cp\\u003eThis is the first documented report worldwide of the accidental isolation of Leish-mania in dog mesenchymal stem cell (MSC) cultures. This unprecedented finding highlights the urgent need to establish rigorous standards in the selection of MSC donors. Once inoculated into the host, Leishmania invades any cell of the mononuclear phago-cytic system [\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e]. However, other cells have already been reported to be susceptible to Leishmania, such as amniotic epithelial cells, fibroblasts [\\u003cspan citationid=\\\"CR22\\\" class=\\\"CitationRef\\\"\\u003e22\\u003c/span\\u003e], hepatocytes [\\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e23\\u003c/span\\u003e] and mesenchymal stem cells derived from adipose tissue [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eThe findings of this report highlight the limitations of laboratory tests for detecting leishmaniasis in dogs, especially recent infections. The use of serological tests such as indirect immunofluorescence (IFI) and enzyme-linked immunosorbent assay (ELI-SA) was not effective in detecting Leishmania in the animals in this report. Although these tests are recommended by the Minist\\u0026eacute;rio da Agricultura, Pecu\\u0026aacute;ria e Abastecimento - MAPA (the Brazilian regulatory body) as screening tests, they were probably carried out at a time when the animals had not yet seroconverted. It is expected that during canine visceral leishmaniasis (CVL), symptomatic dogs and those with high parasitism are associated with an increase in immunoglobulins IgG, IgG2, IgM, IgA and IgE, while asymptomatic dogs and those with low parasitism are associated with an increase in IgG1 [\\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e]. The chronic course of the disease, the delay in seroconversion, cross-reactions in the tests are all known mechanisms that hinder diagnosis and can result in the disease being detected several weeks after infection [\\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eThe parasitological method is highly specific and the identification of just one amastigote form is enough to determine the test as positive. The serological diagnostic methods of enzyme-linked immunosorbent assay and indirect immunofluorescence reaction are recommended by the MAPA, but they can cross-react and do not differentiate between current and past infections. Even so, the dogs in the study were able to evade these diagnostic methods at the time of the first test. Currently, PCR-based techniques are the main diagnostic approach due to their high sensitivity, as well as allowing the assessment of the parasite load and the identification of the Leishmania species [\\u003cspan citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e26\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eAs an alternative to improve the chances of identifying a dog infected with Leishmania, the MAPA highlights the use of Polymerase Chain Reaction (PCR) tests. PCR is a molecular technique capable of detecting Leishmania DNA in blood or tissue samples, providing higher specificity and confirming the infection. Additionally, the culture of Leishmania from tissue samples, such as bone marrow or skin, can also be performed to validate the presence of the infection. Biopsies of affected tissues, such as the skin, can be taken to confirm the presence of the parasite. However, there are indications that for more effective screening there are tests that can detect parasite infection earlier, such as ELISAp (ELISA with promastigote-coated plates) and especially Western blotting [\\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eOne of the main challenges of stem cell therapy is ensuring its safety. Although stem cells have shown remarkable therapeutic potential in pre-clinical studies, their use in humans remains largely experimental. Concerns about the safety of stem cell therapy include the risk of tumorigenesis, immunogenicity, and the possibility of transmission of infectious diseases, including parasites. These risks are particularly relevant in the context of allogeneic stem cell transplantation, in which stem cells from a donor are used to treat a patient [\\u003cspan citationid=\\\"CR27\\\" class=\\\"CitationRef\\\"\\u003e27\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eStem cell therapy is gaining popularity as a possible treatment for various conditions in dogs, including osteoarthritis, autoimmune diseases, and spinal cord injuries [\\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e28\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR29\\\" class=\\\"CitationRef\\\"\\u003e29\\u003c/span\\u003e]. The use of autologous mesenchymal stem cells (MSCs) has been shown to be safe and effective in reducing pain and inflammation, improving mobility and quality of life, and promoting tissue repair in dogs [\\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e28\\u003c/span\\u003e]. However, stem cell therapy is not without its risks. One potential risk is the development of tumors or other adverse effects resulting from the uncontrolled growth or differentiation of transplanted cells [\\u003cspan citationid=\\\"CR29\\\" class=\\\"CitationRef\\\"\\u003e29\\u003c/span\\u003e]. Another risk is the possible transmission of infectious diseases, including viruses and bacteria, using contaminated stem cell preparations [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eThe application of amphotericin cannot be considered a limitation of the study because even though the drug has a known anti-leishmanial effect, the dose used is considered lethal to only 50% of the Leishmania. spp parasites [\\u003cspan citationid=\\\"CR30\\\" class=\\\"CitationRef\\\"\\u003e30\\u003c/span\\u003e], so it was not able to eliminate all the parasites of the species in the samples.\\u003c/p\\u003e \\u003cp\\u003eDespite the risks, the use of stem cells in veterinary medicine has intensified and in some places is even available to the public. Examples include the Animal Medical Center in New York City, USA, which offers stem cell therapy for a variety of diseases in dogs and cats, including osteoarthritis, intervertebral disc disease and chronic kid-ney disease; the Veterinary Specialty Hospital of the Carolinas in North Carolina, USA and the Veterinary Regenerative Medicine Center in Ontario, Canada.\\u003c/p\\u003e \\u003cp\\u003eThis study has limitations such as the lack of identification of the species of Leishmania that was isolated along with the mesenchymal stem cells, as well as the absence of more comprehensive details about the parasite. In retrospect, it is crucial to point out that this incident occurred unexpectedly during a previous study. At the time, we were so frustrated that all the material was discarded. It was only many years later that we realized the importance of what we had, when it was no longer possible to carry out additional tests to identify more in-depth details about the parasite.\\u003c/p\\u003e \"},{\"header\":\"Conclusion\",\"content\":\" \\u003cp\\u003eThe finding of amastigote forms of Leishmania in these dogs again raises questions about the presumed safety of stem cell therapy. Therefore, there is an urgent need to develop standardized protocols for the characterization and quality control of stem cells used in clinical practice, as well as to establish clear guidelines for conducting clinical studies that evaluate the safety and efficacy of stem cell therapy. These efforts will be key to ensuring that stem cell therapy can be used safely and effectively to improve the lives of patients with various diseases and injuries.\\u003c/p\\u003e \\u003c/div\\u003e \"},{\"header\":\"Declarations\",\"content\":\"\\u003cul\\u003e\\n \\u003cli\\u003eFunding: No external funding received.\\u003c/li\\u003e\\n \\u003cli\\u003eConflict\\u0026nbsp;of\\u0026nbsp;interest/Competing\\u0026nbsp;interests:\\u0026nbsp;The authors declare that they have no conflict of interest, are scholars of stem cell therapy and are in favor of its clinical use if it is judicious and within what the legislation allows.\\u003c/li\\u003e\\n \\u003cli\\u003eEthics approval and consent to participate: The findings of this work were observed during the conduct of the study: CAMARA, B.O.S.; OCARINO, N.M.; BERTASSOLI, B.M.; MALM, C.; ARA\\u0026Uacute;JO, F.R.; REIS, A.M.S.; JORGE, E.C.; ALVES, E.G.L.; SERAKIDES, R. Differentiation of canine adipose mesenchymal stem cells into insulin-producing cells: comparison of different culture medium compositions. DOMESTIC ANIMAL ENDOCRINOLOGY, v. 74, p. 106572, 2021.\\u0026nbsp;All experimental protocols were approved by the licensing/ ethics committee of the following brasilian institutions\\u0026nbsp;Funda\\u0026ccedil;\\u0026atilde;o de Amparo \\u0026agrave; Pesquisa de Minas Gerais (Fapemig), Conselho Nacional de Desenvolvimento Cient\\u0026iacute;fico e Tecnol\\u0026oacute;gico, and Coordena\\u0026ccedil;\\u0026atilde;o de Aperfei\\u0026ccedil;oamento de Pessoal de N\\u0026iacute;vel Superior. The study was also screened by N\\u0026uacute;cleo de C\\u0026eacute;lulas Tronco e Terapia Celular Animal (NCT-TCA) da Escola de Veterin\\u0026aacute;ria da Universidade Federal de Minas Gerais, Universidade de Uberaba (UNIUBE) and Laborat\\u0026oacute;rio de Biologia Oral e do Desenvolvimento, Departamento de Morfologia do Instituto de Ci\\u0026ecirc;ncias Biol\\u0026oacute;gicas da Universidade Federal de Minas Gerais.\\u0026nbsp;The methods were carried out in accordance with the relevant guidelines and regulations and can be verified in the study mentioned above.\\u003c/li\\u003e\\n \\u003cli\\u003eThe dogs were not client owned; they had been made available by the research institution to be used in another high-level study.\\u003c/li\\u003e\\n \\u003cli\\u003eConsent\\u0026nbsp;for\\u0026nbsp;publication: All authors have read and agreed to the published version of the manuscript.\\u003c/li\\u003e\\n \\u003cli\\u003eData Availability Statement: Data sharing not applicable to this article as no datasets were generated or analyzed during the current study. However, it is important to note that the aim of this article is to register an undocumented accidental finding which occurred while conducting another work was being conducted. The findings of this work were observed during the conduct of the study: CAMARA, B.O.S.; OCARINO, N.M.; BERTASSOLI, B.M.; MALM, C. ; ARA\\u0026Uacute;JO, F.R. ; REIS, A.M.S. ; JORGE, E.C. ; ALVES, E.G.L. ; SERAKIDES, R. . Differentiation of canine adipose mesenchymal stem cells into insulin-producing cells: comparison of different culture medium compositions. DOMESTIC ANIMAL ENDOCRINOLOGY, v. 74, p. 106572, 2021. Available at https://www.sciencedirect.com/science/article/abs/pii/S0739724020301399?via%3Dihub\\u003c/li\\u003e\\n \\u003cli\\u003eMaterials availability: Not applicable\\u003c/li\\u003e\\n \\u003cli\\u003eCode availability: Not applicable\\u003c/li\\u003e\\n \\u003cli\\u003eAuthor contribution: All authors contributed equally to all parts of the project.\\u003c/li\\u003e\\n \\u003cli\\u003eAuthor Contributions: All authors contributed equally to all parts of the project. All authors have read and agreed to the published version of the manuscript.\\u003c/li\\u003e\\n \\u003cli\\u003e\\u003cstrong\\u003eAcknowledgements.\\u0026nbsp;\\u003c/strong\\u003eThe authors would like to thank the University of Uberaba and the Stem Cell and Animal Cell Therapy Center, NCT-TCA, Department of Clinic and Surgery, Veterinary School, Federal University of Minas Gerais, for providing the physical structure and resources to carry out the study.\\u003c/li\\u003e\\n\\u003c/ul\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\u003cli\\u003e\\u003cspan\\u003eAlvar, J.; V\\u0026eacute;lez, I. D.; Bern, C.; Herrero, M.; Desjeux, P.; Cano, J.; Jannin, J.; den Boer, M.; WHO Leishmaniasis Control Team. \\u003cem\\u003eLeishmaniasis worldwide and global estimates of its incidence\\u003c/em\\u003e. 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Infectious Disorders - Drug Targets\\u003c/em\\u003e [s.d.], \\u003cem\\u003e20\\u003c/em\\u003e(6), 822\\u0026ndash;827. \\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003ehttps://dx.doi.org/10.2174/1871526519666191015170627\\u003c/span\\u003e\\u003cspan address=\\\"10.2174/1871526519666191015170627\\\" targettype=\\\"DOI\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e\\u003c/span\\u003e\\u003c/li\\u003e\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":true,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"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\":\"Leishmaniasis 1, Cellular therapy 2, Zoonosis3\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-4591915/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-4591915/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003eThe aim of this case report is to record the finding of leishmaniasis-causing parasites in mesenchymal stem cells from dogs from a non-endemic area, which were negative when submitted to the RIFI and ELISA tests, a fact that had not been documented until now. This demonstrates that this widely distributed and lethal zoonosis can escape traditional means of diagnosis and that stem cell therapy has the potential to be a source of transmission of the disease. Although the relative safety of stem cell therapy is presumed, the possible risks associated with its use, especially the risk of parasite transmission, cannot be ignored. It is therefore essential to develop rigorous screening and testing protocols to ensure the safety of stem cell therapy.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Therapeutic use of mesenchymal stem cells may be a means of transmitting leishmaniasis in dogs\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2024-07-23 16:59:52\",\"doi\":\"10.21203/rs.3.rs-4591915/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"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\":\"3a4b2fea-4028-4015-ba5f-30685f5fae47\",\"owner\":[],\"postedDate\":\"July 23rd, 2024\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"posted\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2024-08-31T10:36:21+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2024-07-23 16:59:52\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-4591915\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-4591915\",\"identity\":\"rs-4591915\",\"version\":[\"v1\"]},\"buildId\":\"qtupq5eGEP_6zYnWcrvyt\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}