MO875SEROCONVERSION RATE AND PERSISTANCE OF IGG RESPONSE TO SARS-COV2 IN HEMODIALYSIS PATIENTS. A CASE SERIES STUDY

Abstract

Abstract Background and Aims Higher incidence and worse outcome of coronavirus disease (COVID-19) are observed in dialysis patients, mainly due to weak immune response. However, little is known about seroconversion ability and duration of antibody response after COVID-19 in this group. The aim of this study was to estimate the seroconversion rate and the persistence of IgG response to SARS-CoV2 in dialysis patients. Method Four (4) dialysis patients previously infected with SARS-CoV2 were included in this study. Initially, all patients were tested for the presence of IgG antibodies 21-35 days after the onset of their symptoms. The cut-off value for positivity was a ratio of ≥ 1.4. Those patients with at least two consecutive positive samples were defined as seropositives. Seropositives were then having their antibodies tested monthly for a maximum period of six months or until the first negative result. Duration of antibody persistence was defined as the time between the day IgG were last detected and the day of onset of infection. Results All four patients were seropositives after the initial test (seroconversion rate = 100%) with a mean IgG ratio of 6.44 (±1.28). Median follow up period was 128 (range 96-193) days. Median duration of antibody persistence was 153 (range 103-193) days. By the sixth month, IgG had turned negative in two of four patients (rate = 50%). Conclusion In our study, dialysis patients showed a remarkable seroconversion rate after infection with SARS-CoV2. However, a rapid decline of IgG antibodies was observed in half of them.