SARS-CoV-2 and dialysis: humoral response, clinical and laboratory impacts before vaccination.

Background: Patients with kidney disease on Hemodialysis (HD) are susceptible to Coronavirus Disease (COVID-19) due to multiple risk factors.

Aim: This study aims to report the prevalence of antibodies against SARS-CoV-2 among patients on hemodialysis before vaccination in Brazil and to compare with clinical, demographic, and laboratory data.

Methods: Blood samples from 398 Chronic Kidney Disease (CKD) patients treated in three different private institutions in Rio de Janeiro State, Brazil were submitted to the total anti-SARS-CoV-2 testing. Kidney, liver, and hematological markers were also determined. Respiratory samples were tested by real-time PCR for SARS-CoV-2 RNA and positive samples were subjected to high-throughput sequencing on the MinION device.

Results: Overall, anti-SARS-CoV-2 prevalence was 54.5 % (217/398) and two individuals had SARS-CoV-2 RNA with variant B.1.1. High anti-SARS-CoV-2 seroprevalence was found in male gender and those with hospital admission in the last 3-months before the inclusion in the study. Lower red blood cell count was observed in the anti-SARS-CoV-2 seropositive group. High levels of anti-SARS-CoV-2 were found in those who reported symptoms, had low levels of eosinophils and low hematocrit, and who practiced physical activity.

Conclusion: High prevalence of anti-SARS-CoV-2 was found in CKD patients before the universal immunization in Brazil suggesting that dialysis patients were highly exposed to SARS-CoV-2.