Immune responses of patients on maintenance hemodialysis after infection by SARS-CoV-2: a prospective observational cohort study.

BACKGROUND: Immune dysregulation in patients with acute COVID-19 under chronic hemodialysis (CHD) is fully not elucidated. The changes of mononuclear counts and mediators before and after HD and associations with final outcome were studied. METHOD: In this prospective study, hospitalized patients with moderate-to-severe COVID-19 under CHD and matched comparators under HD were analyzed for their absolute counts of lymphoid cells and circulating inflammatory mediators. Blood samples were collected before start and at the end of the first HD session; dialysate samples were also collected. RESULT: Fifty-nine patients with acute COVID-19 under CHD and 20 uninfected comparators under CHD were enrolled. Circulating concentrations of tumor necrosis factor-alpha (TNFα), interleukin (IL)-10, interferon-γ and platelet-derived growth factor-A were increased in patients. Concentrations of mediators did not differ before and after HD. Significant decreases of CD4-lymphocytes and CD19-lymphocytes were found in patients. The decrease of the expression of HLA-DR on CD14-monocytes was associated with unfavorable outcome (defined as WHO-CPS 6 or more by day 28); increased counts of CD19-lymphocytes were associated with better outcomes. CONCLUSION: Patients under CHD develop an inflammatory reaction to SARS-CoV-2 characterized by increase of inflammatory mediators, decrease of circulating T-lymphocytes and decrease of the expression of HLA-DR on CD14-monocytes.

Clinical presentation and outcomes of chronic dialysis patients with COVID-19: A single center experience from Greece.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is still a menacing pandemic, especially in vulnerable patients. Morbidity and mortality from COVID-19 in maintenance hemodialysis (MHD) patients are considered worse than those in the general population, but vary across continents and countries in Europe. AIM: To describe the clinical course and outcomes of hospitalized MHD patients with COVID-19 in a retrospective observational single center study in Greece. METHODS: We correlated clinical, laboratory, and radiological data with the clinical outcomes of MHD patients hospitalized with COVID-19 during the pandemic. The diagnosis was confirmed by real-time polymerase chain reaction. Outcome was determined as survivors vs non-survivors and "progressors" (those requiring oxygen supplementation because of COVID-19 pneumonia worsening) vs "non-progressors". RESULTS: We studied 32 patients (17 males), with a median age of 75.5 (IQR: 58.5-82) years old. Of those, 12 were diagnosed upon screening and 20 with related symptoms. According to the World Health Organization (WHO) score, the severity on admission was mild disease in 16, moderate in 13, and severe in 3 cases. Chest computed tomography (CT) showed 1-10% infiltrates in 24 patients. Thirteen "progressors" were recorded among included patients. The case fatality rate was 5/32 (15.6%). Three deaths occurred among "progressors" and two in "non-progressors", irrespective of co-morbidities and gender. Predictors of mortality on admission included frailty index, chest CT findings, WHO severity score, and thereafter the increasing values of serum LDH and D-dimers and decreasing serum albumin. Predictors of becoming a "progressor" included increasing number of neutrophils and neutrophils/lymphocytes ratio. CONCLUSION: Patients on MHD seem to be at higher risk of COVID-19 mortality, distinct from the general population. Certain laboratory parameters on admission and during follow-up may be helpful in risk stratification and management of patients.