Anti-Glomerular Basement Membrane Disease in a Critically Ill Patient: A Diagnostic and Therapeutic Challenge in Occidente de Mexico

Introduction: Anti-glomerular basement membrane (anti-GBM) disease is a rare but severe cause of rapidly progressive glomerulonephritis (GN). Its diagnosis can be particularly challenging in critically ill patients, where multiple organ failures and infectious processes coexist, masking the primary origin of renal injury (AKI) Case Description: A previously healthy 22-year-old male was admitted to the hospital with diagnosis of necrotizing acute pancreatitis associated with acute respiratory distress syndrome (ARDS), and anuria. Rapidly required mechanical ventilation and urgent hemodialysis and Acinetobacter baumannii nosocomial pneumonia, Burkholderia cepacia catheter-associated bloodstream infection, and candidemia, without echocardiographic evidence of endocarditis. Due to vascular access infection, peritoneal dialysis (DP). Initial immunological included ANAs 1:160, anti-dsDNA, ANCA, negatives. Renal biopsy (BR), revealing diffuse crescentic glomerulonephritis with fibrinoid necrosis and linear IgG deposits along the glomerular basement membrane, Anti-GBM antibodies were positive by ELISA. Once sepsis was controlled Immunosuppressive therapy with rituximab. Discussion: Anti-GBM disease accounts for less than 1% of all GN, yet early diagnosis is critical to prevent irreversible renal damage. In this case, diagnosis was delayed due to overlapping sepsis, ARDS, and multiorgan failure, complicating the identification of the primary cause of AKI. This case highlights the importance of maintaining a high index of suspicion for rare autoimmune causes of glomerulonephritis, such as anti-GBM disease, particularly in critically ill patients with unexplained persistent renal failure. Early recognition and prompt initiation of immunosuppressive therapy, once infectious complications are controlled, are essential to improve outcomes.