A case of COVID-19 reinfection in a hemodialysis patient: the role of antibody in SARS-CoV-2 infection.

Hemodialysis patients are vulnerable to severe and lethal COVID-19, and their protective immunity against COVID-19 is not yet fully understood. Therefore, we report a case of COVID-19 reinfection in a hemodialysis patient 81 days after the first episode and discuss the role of antibodies in SARS-CoV-2 infection. A hemodialysis patient developed asymptomatic COVID-19 due to an outbreak in a hospital on October 29th, 2020. As he was hospitalized and did not develop any symptoms, he was discharged on November 9th. On January 18th, he presented with symptomatic COVID-19 due to close household contact. Then, he developed respiratory failure and was transferred to National Center for Global Health and Medicine if he would need intensive care. He recovered with oxygen inhalation, favipiravir, and steroid treatment, and was discharged on February 12th. To evaluate anti-SARS-CoV-2 antibodies during two hospital stays, we measured immunoglobulin (Ig) G specific for S1 subunit of Spike (S) protein of SARS-CoV-2 (IgG-S1) , IgG specific for the full-length S protein (anti-Spike IgG) and neutralizing antibodies. No seroconversion occurred 5 days after initial infection, the seroconversion of IgG-S1 was observed 10 days after the second infection. Similar to IgG-S1 antibody titer results, anti-Spike IgG and neutralizing antibodies increased from 12 days after the second infection. In conclusion, we experienced a case of COVID-19 reinfection in a hemodialysis patient 81 days after the first episode and showed the kinetics and role of antibodies in SARS-CoV-2 infection. Further studies are needed to understand SARS-CoV-2 reinfection risk in hemodialysis patients and its clinical significance.