Low rate of COVID-19 pneumonia in kidney transplant recipients-A battle between infection and immune response?

Background With COVID-19 pandemic, concerns about kidney transplant recipients are rising. However, the incidence, clinical course, outcome, and predictive factors of disease severity are obscured. Methods We describe clinical and laboratory manifestations, radiologic findings, clinical course, and finally outcome of kidney transplant recipients with COVID-19 pneumonia. Results Of 2493 kidney transplant recipients under follow-up in our clinic, 19 cases (4 cases diagnosed based on radiologic findings) were admitted. The mean age of patients was 47.6 +/- 12.4 years, and the mean time from transplantation was 115.6 +/- 70.3 months. Lymphopenia and eosinopenia were 84.2% and 78.9%, respectively. Nine patients did not survive the hospital course. History of acute rejection during the past 12 months, diabetes, higher N/L ratio, lower platelet count, elevated N/L x CRP, higher levels of LDH, positive D-dimer, higher troponin, and prolonged PT were associated with mortality. Among patients with positive COVID-19 test, history of acute rejection, low platelet count, and positive D-dimer were associated with poor outcome. Treatment with cyclosporine was associated with better clinical outcome. Conclusions Low rate of admission in transplant recipients specially in the very first years of transplantation might be due to protective effects of immunosuppressive agents against cytokine storm or modification of immunity function. We suggest evaluation of T-cell number, function, and cytokine profile as a guide to manage COVID-19 mainly in patients with higher risk of mortality.