New-onset minimal change disease following the Moderna COVID-19 vaccine.

We report the case of nephrotic syndrome after COVID-19 vaccination. The patient was a man in his 30s with no comorbidities other than atopic dermatitis. Over the course of 2 weeks after the first COVID-19 vaccination, systemic oedema gradually appeared. He was referred to the nephrology department for investigation of the systemic oedema. On admission, he presented with pitting oedema in his lower extremities. Initial examinations revealed massive urinary protein and decreased serum albumin, at 13.9 g/g Cr and 1.5 g/dL, respectively. Renal biopsy was performed, and minimal change disease was diagnosed. Prednisolone 60 mg/day was promptly started on the 5th day of hospitalisation, and complete remission was achieved on the 12th day. Prednisolone was once tapered off in 1.5 years successfully though minimal change disease was relapsed in 1 month after the steroid withdrawal.