菱田 英里華

Immunoglobulin A nephropathy (IgAN) is characterized by diverse clinicopathological phenotypes. Herein we present a follow-up study of previously reported identical twin sisters with IgAN. The older sister exhibited more severe kidney histopathology and proteinuria and a lower birthweight than did her younger sister, and only the older sister experienced two childbirths. These raised concerns regarding her kidney outcomes. However, with timely multidisciplinary treatments, the older sister's kidney function remained preserved after 20 years of IgAN history. Our findings indicate the significant contribution of environmental/epigenetic factors to IgAN progression and the need for tailored medical care corresponding to life events.

A 79-year-old male patient with type 2 diabetic nephropathy and hypertension was admitted to our hospital because of acute kidney injury with significantly elevated serum creatinine (8.12 mg/dL) and urinary β2-microglobulin (β2MG, 31,748 μg/L) levels. α-Glucosidase inhibitor (α-GI) miglitol, started two weeks prior to presentation, was discontinued because drug-induced acute interstitial nephritis (AIN) was suspected. Renal biopsy revealed AIN and diabetic nephropathy. The drug-induced lymphocyte stimulation test for miglitol was also positive. After the discontinuation of miglitol, the urinary β2MG levels decreased to the normal range. This case raises the possibility that α-GI miglitol can worsen the renal function in patients with underlying renal dysfunction.

We herein report a case of acute kidney injury (AKI) presenting as acute interstitial nephritis (AIN) after the first dose of the BNT162b2 mRNA vaccine against coronavirus disease 2019 (COVID-19). A 69-year-old man with a history of diabetes and hypertension presented with AKI 4 days after receiving the vaccine. Despite the administration of methylprednisolone pulse treatment, his renal function worsened, which prompted us to initiate temporal hemodialysis. His renal function subsequently improved, and a renal biopsy confirmed AIN and glomerular capillary IgA deposition without apparent crescents. The clinical history and histological findings suggest a relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and AIN as a rare side effect.