(1425) Goodpasture Syndrome Presenting as Gastrointestinal Hemorrhage

Introduction: Goodpasture’s Syndrome (GS) is a rare small vessel vasculitis where circulating antibodies target the glomerular basement membrane and alveolar basement membranes, causing rapidly progressive glomerulonephritis with or without alveolar hemorrhage. Younger patients typically present with pulmonary hemorrhage while older adults have predominantly isolated glomerulonephritis. Gastrointenstinal hemorrhage is very rarely reported in GS. We present the case of a 77-year-old female presenting with lower GI bleed, found to have biopsy proven GS.

Description: A 77-year-old female presented with bloody diarrhea and diffuse abdominal pain for one day, alongside decreased urine output for a few days. She had flu-like symptoms three weeks prior. Vital signs were stable, and the physical exam revealed mild lower abdominal tenderness. Laboratory results showed normotic anemia (Hgb 8.1 g/dL), severe kidney impairment (BUN 192 mg/dL, creatinine 22.1 mg/dL, eGFR 1.4 mL/min/1.73 m²), hyperkalemia (K 7.0 mmol/L) and high anion gap metabolic acidosis. Urinalysis showed large amounts of protein and blood, with high protein-creatinine ratio (7.060 g). The patient was admitted to the ICU, where she was treated for acute renal failure and hyperkalemia. Further evaluation revealed low compliment levels. Anti-GBM antibodies were elevated with positive p-ANCA/MPO. Renal ultrasound and CT of the abdomen were unremarkable. A kidney biopsy revealed diffuse crescentic glomerulonephritis with linear IgG, kappa, and lambda staining along glomerular capillary loops, consistent with GS. ICU management included hemodialysis, plasmapheresis, high dose glucocorticoids, and rituximab. The GI hemorrhage resolved with treatment of GS. Therefore it was felt to be a vasculitis bleed. The patient was ultimately discharged home in stable condition.

Discussion: GS is rare, with approximately two cases per million per year. GS presenting with gastrointestinal hemorrhage is even rarer, being limited to a few case reports. The pathophysiology is thought to be small vessel vasculitis in the gut, although this has never been proven. In our case, the GI bleed resolved with treatment of GS, suggesting a common pathophysiology. More research is needed.