Incidence and Immunologic Analysis of Coronavirus Disease (COVID-19) in Hemodialysis Patients: A Single-Center Experience

Objectives: COVID-19 is a great threat to the modern world and significant threat to immunocompromised patients, including patients with chronic renal failure. We evaluated COVID-19 incidence among our hemodialysis patients and investigated the most probable immune mechanisms against COVID-19. Materials and Methods: Baskent University has 21 dialysis centers across Turkey, with 2420 patients on hemodialysis and 30 on peritoneal dialysis. Among these, we retrospectively evaluated 602 patients (257 female/345 male) with chronic renal failure receiving hemodialysis as renal replacement therapy; 7 patients (1.1%) were infected with SARS-CoV-2. We retrospectively collected patient demographic characteristics, clinical data, and immunological factors affecting the clinical course of the disease. We divided patients into groups and included 2 control groups ( individuals with normal renal functions): group I included COVID-19-positive patients with normal renal function, group II included COVID-19-positive hemodialysis patients, group III included COVID-19-negative hemodialysis patients, and group IV included COVID-19-negative patients with normal renal function. Lymphocyte subsets in peripheral blood and typing of human leukocyte antigens were analyzed in all groups, with killer cell immunoglobulin-like receptor genes analyzed only in COVID-19-positive patients and healthy controls. Results: No deaths occurred among the 7 COVID-19-positive hemodialysis patients. Group I patients were significantly older than patients in groups II and III ( P = .039, P = .030, respectively) but not significantly different from group IV (P = .060). Absolute counts of natural killer cells in healthy controls were higher than in other groups (but not significantly). Activated T cells were significantly increased in both COVID-19-positive groups versus COVID-19-negative groups. Groups showed significant differences in C and DQ loci with respect to distribution of alleles in both HLA classes. Conclusions: Although immunocompromised patients are at greater risk for COVID-19, we found lower COVID-19 incidence in our hemodialysis patients, which should be further investigated in in vitro and molecular studies.