Case Report: Anti-glomerular basement membrane disease during pregnancy with favorable renal outcome, sequential biopsies, and dual anti-α1/α3(IV) and anti-LM521 antibodies.

Anti-glomerular basement membrane (anti-GBM) disease during pregnancy is rare and often life-threatening. We report a G4P1 woman who developed atypical anti-GBM disease at 13 weeks of gestation. Serial kidney biopsies demonstrated a reduction in active necrotizing lesions from 64.3% to 30.8% following early intensive immunosuppression and pregnancy termination. Western blot identified circulating autoantibodies against type IV collagen α1/α3 chains and laminin-521 (LM-521)-a novel finding in anti-GBM disease during pregnancy. Multidisciplinary management, including plasma exchange, high-dose methylprednisolone, hemodialysis, pregnancy termination, and obinutuzumab for serologic recurrence, enabled discontinuation of dialysis and partial renal recovery with stable kidney function. This case provides histological evidence, through sequential kidney biopsies, that early intensive immunotherapy combined with pregnancy termination can halt active necrotizing lesions and facilitate tissue repair. It also examines the potential association between specific autoantibody subtypes (anti-α1/α3 chains and LM521) and disease phenotypes, offering new insights into anti-GBM disease during pregnancy.