Potent SARS-CoV2-specific T-cell response in asymptomatic hemodialysis patients with hidden COVID-19 infection history.

BACKGROUND: COVID-19-related immune responses in patients with end-stage renal disease (ESRD) are characterized in detail by the humoral response, but their cellular immunity has not been clarified. Here, we evaluated virus-specific T cells in parallel with serology-related tests. METHODS: In this study, 104 ESRD patients at the hemodialysis ward of Imam Reza hospital at Tabriz (Iran) were enrolled. After blood sampling, SARS-CoV2-specific humoral and cellular immune responses were evaluated by SARS-CoV2-specific IgM/IgG ELISA and peptide/MHCI-Tetramers flow cytometry, respectively. RESULTS: Our results showed that 14 (13.5%) and 45 (43.3%) patients had specific SARS-CoV2 IgM and IgG in their sera, respectively. Immunophenotyping for SARS-CoV2-specific CD8+ T lymphocytes revealed that 68 (65.4%) patients had these types of cells. Among SARS-CoV2-specific CD8+ T lymphocytes positive subjects, 13 and 43 individuals had positive results for specific SARS-CoV2 IgM and IgG existence, respectively. Also, there was a relationship between specific SARS-CoV2 IgM (p = 0.031) and IgG (p < 0.0001) existence and having SARS-CoV2-specific TCD8+ lymphocytes in the studied population. CONCLUSION: Despite not having clinical symptoms, a high rate of SARS-CoV2-specific T-cell response in asymptomatic ESRD patients may reveal a high burden of asymptomatic COVID-19 infection in these patients.

Prevalence of SARS-CoV-2 Specific Antibodies in Asymptomatic Hemodialysis Patients.

BACKGROUND: Since the outbreak of the new coronavirus pandemic, the importance of carrying out an infection check to prevent acquisition and transmission among end-stage renal disease patients (ESRD) under maintenance hemodialysis (MHD) has become a major concern in the health care system. Applying serology screening tests could enlighten the view with regards to disease prevalence in dialysis wards. METHODS: We subjected 328 end-stage renal disease patients to maintenance hemodialysis. After dividing patients into suspicious and non-suspicious groups for COVID-19 infection based on their clinical manifestation, they were investigated for SARS-CoV-2 specific IgM and IgG screening against nucleoprotein (NP), spike protein (SP), and receptor-binding domain (RBD), utilizing our recently developed ELISA tests. RESULTS: We found that approximately 10.1% of asymptomatically tested cases were antibody positive. Although IgG positivity showed a higher prevalence than IgM across all three virus antigen subunits, there were no significant differences among mentioned immunoglobulins of the studied groups. The most prevalent antibody was from the IgG subtype against virus nucleoprotein (NP), while the lowest prevalence was attributed to receptor-binding domain (RBD) IgM. CONCLUSION: High seropositive rate among asymptomatic end-stage renal disease patients, as a sample of high-risk population, reflected the importance of considering SARS-CoV-2 specific antibody screening for disease containment.

Current status of COVID-19 among hemodialysis patients in the East Azerbaijan Province of Iran.

INTRODUCTION: Management of vulnerable patients during the COVID-19 pandemic requires careful precautions. Hemodialysis patients constitute a large group of at-risk patients that not only suffer from a compromised immune system but also are at a higher risk due to frequent admission to healthcare units. Therefore, a better understanding on the pathogenesis and possible risk factors of COVID-19 in hemodialysis patients is of high importance. METHODS: A total of 670 maintained hemodialysis patients from all dialysis units of the East Azerbaijan Province of Iran, including 44 COVID-19 patients were included in the present study. Possible associations between the backgrounds of patients and the incidence of COVID-19 were assessed. Also, hemodialysis patients with COVID-19 were compared to 211 nonhemodialysis COVID-19 patients. FINDINGS: Chronic glomerulonephritis patients and those with blood group A demonstrated a higher incidence of COVID-19. On the other hand, patients with blood group AB+ and those with hypertension etiology of kidney failure demonstrated a lower incidence of COVID-19. Hemodialysis patients with COVID-19 had higher counts of polymorphonuclears (PMNs) in their peripheral blood compared to other COVID-19 patients. DISCUSSION: A better comprehension on the risk factors associated with COVID-19 in hemodialysis patients can improve our understanding on the pathogenesis of COVID-19 in different situations and help the enhancement of current therapeutics for COVID-19 in hemodialysis patients.