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 (p<0.01). Though CRP decreased more in rIL-2 group, it did not show a significant difference between the two groups (p>0.05).Conclusion: RIL-2 might be a prospective adjuvant therapy for severe COVID-19 patients by increasing lymphocytes number.