New-onset and relapse of nephrotic syndrome following COVID-19 vaccination: a questionnaire survey in Japan.

Background: Recent clinical reports indicate a correlation between new-onset and relapse of nephrotic syndrome (NS) following coronavirus 2019 (COVID-19) vaccination in patients with glomerular diseases. However, there are no reports of a nationwide survey on NS following COVID-19 vaccination in Japan. Methods: We conducted a web-based survey of council members of the Japanese Society of Nephrology (581 members, 382 facilities) to elucidate the relationship between COVID-19 vaccination and new-onset and relapse of NS. Results: Following COVID-19 vaccination, 27 patients (male: 15, 55.6%) with new-onset (n = 6) and relapse (n = 21) of NS were reported. Of them, 12 (44.4%) patients were diagnosed with minimal change disease at the occurrence of NS. Five patients developed a slight increase in serum creatinine levels; however, none progressed to severe renal dysfunction. Conclusion: Our findings clarify the clinical features of new-onset and relapse of NS following COVID-19 vaccination. Although there was no obvious progression to severe renal dysfunction, clinicians and pathologists should be aware that NS is a potential adverse effect of the vaccines. [ABSTRACT FROM AUTHOR]