Granulomatosis With Polyangiitis Presenting With Kidney Failure: A Case Report.

Granulomatosis with polyangiitis (GPA) is a rare and serious disease associated with antineutrophil cytoplasmic antibody (ANCA) antibodies. It can involve the kidneys and respiratory tract and may present as a pulmonary-renal syndrome. This report presents the case of a 57-year-old man admitted to the nephrology department with acute renal failure and systemic symptoms, including low-grade fever, malaise, and abdominal pain. During hospitalization, laboratory tests revealed rapidly progressive renal failure, elevated inflammatory markers, and oliguria. A subsequent kidney biopsy confirmed pauci-immune necrotizing glomerulonephritis, and serology was positive for PR3-ANCA, supporting the initial diagnosis of GPA. Immunosuppressive therapy was initiated and later adjusted due to complications. Despite these challenges, the patient's clinical status improved, and he was discharged in stable condition.