Unexpected Relapse: Insights Into Granulomatosis With Polyangiitis.

Granulomatosis with polyangiitis (GPA) is a rare vasculitis that can pose a significant mortality risk given its multiorgan involvement and is the most common of the three anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides. Cardinal pathological features include necrotizing granulomas of the respiratory tract, small and medium vessel vasculitis, and glomerulonephritis. Early treatment is imperative to reduce permanent organ damage such as end-stage kidney disease. We describe the first case of GPA relapse 38 years after the initial pulmonary presentation. The patient previously had isolated lung involvement with preserved renal function, but presented with an acute kidney injury, uremia, and several constitutional symptoms. The patient was treated with corticosteroids and intermittent hemodialysis and initiated on immunosuppressants; the clinical course is highlighted by eventual renal recovery. Our purpose is to highlight the importance of treating patients to complete immunological recovery, particularly in GPA vasculitis, to prevent unnecessary relapse and further loss of renal function.