Relapsing polychondritis with glomerulonephritis. Improvement with prednisone and cyclophosphamide.

A 32-year-old man presented with relapsing polychondritis (RP) and microhematuria. A renal biopsy specimen disclosed focal segmental glomerulonephritis with occasional crescents. Immunofluorescent and electron micrographic studies suggested immune complex--mediated glomerular injury. Initially, life-threatening upper airway obstruction responded to high-dose corticosteroid therapy. Subsequently, progressive renal insufficiency and proteinuria caused by increasingly active glomerulonephritis were treated by adding cyclophosphamide, with sustained improvement. This case supports the concept that RP is an immunologically mediated disease and suggests that a regimen of prednisone and cyclophosphamide warrants consideration for use in cases of RP with glomerulonephritis.