Successful treatment of new-onset diabetes mellitus and IgA nephropathy after COVID-19 vaccination: a case report.

De novo glomerular injuries or relapse of nephropathy following COVID-19 vaccine has been reported. Here we present the first case of successful treatment of new-onset diabetes mellitus and biopsy-proven IgA nephropathy after COVID-19 vaccination. A 56-year-old man with no known medical history of renal dysfunction or diabetes mellitus developed both within 3 months after receiving a third dose of inactivated COVID-19 vaccine (Vero cells). His symptoms were characterized by brown urine, severe dry mouth, and excessive thirst. Randomly acquired blood glucose levels exceeded 33.3 mmol/L. A kidney biopsy showed IgA nephropathy. He was started on insulin for glycemic control. After glucocorticoid and cyclophosphamide treatment, oral tablets of repaglinide, combined with acarbose, controlled blood glucose and stabilized kidney function. This case is unique because the kidneys and pancreas were simultaneously affected by the vaccine. Successful treatment of the disease proved that cyclophosphamide combined with glucocorticoids were effective and that blood glucose was successfully controlled. This treatment option could be useful in similar cases in the future.