Characteristics of Changes in Serum IL-6 and IL-10 Levels in Patients with COVID-19 and Their Relationship with Disease Progression: A Possible Hypothesis

Pulmonary impairment in COVID-19 remains significant therapeutic difficulties. Severe respiratory distress syndrome can lead to lung tissue damage and even irreversible pulmonary fibrosis. Cytokines play important role in regulating cell growth, differentiation, and modulating the effects of the immune response. IL-6 is capable of responding rapidly to organism injury, mediating the acute phase response in the liver, stimulating the production of C-reactive protein and fibrinogen, as well as stimulating the proliferation, differentiation and enhancing the function of cells involved in the immune response, and playing an important role in the body's immune response against infection. Interleukin-10(Il-10) is a classical cytokine synthesis inhibitor, which plays a variety of immunosuppressive functions. It acts as an anti-inflammatory agent by inhibiting the activation, migration and adhesion of inflammatory cells, while strongly inhibiting the synthesis of interleukin-1 (IL-1), IL-6, IL-8 and tumor necrosis factor-α (TNF-α) at the transcriptional level. We hypothesized that an excessive IL-6 to IL-10 burden or disproportion disid of the two cytokines could contribute to the deterioration in COVID-19. Otherwise, maintaining the appropriate level of IL-10 later in the course of the disease was beneficial for the recovery of pulmonary function. In addition, we present a study in which serum samples from COVID-19 patients treated with Mesenchymal stem cells (MSCs) were measured by serum levels of c-reactive protein (CRP), Interleukin-6(IL-6) and interleukin-10(Il-10),so that we can observe the activation of cytokines at different stages of COVID-19. If the hypothesis is correct(Based on the hypothesis), new targeted therapeutic ideas could reduce the occurrence of excessive inflammatory responses to COVID-19 and thus potentially restore lung function and quality of life in cured patients.