Membranous nephropathy complicating relapsing polychondritis: A case report

Background: Relapsing polychondritis is a rare systemic disease characterized by recurrent inflammation, and often destruction, of cartilaginous tissues. Renal manifestations are rare. Membranous nephropathy complicating relapsing polychondritis has been reported only once previously, and there is no standardized treatment for membranous nephropathy associated with relapsing polychondritis. Case presentation: A 67-year-old Caucasian man with a history of chronic renal disease presented with 9 months of progressive dyspnea on exertion and 5 months of erythema, pain, and collapse of auricular cartilage. Imaging studies confirmed active inflammation of laryngeal, auricular, and costal cartilage and he was diagnosed with relapsing polychondritis. Patient had longstanding proteinuria and renal biopsy demonstrated membranous nephropathy. Patient initially showed renal and respiratory improvement with etanercept, a tumor necrosis factor alpha inhibitor, treatment. However, subsequent disease and treatment-related complications led to a progressive overall clinical decline and patient died approximately 1 year following relapsing polychondritis diagnosis. Conclusion: Membranous nephropathy may rarely complicate relapsing polychondritis. In our case, both the cartilaginous inflammation and the renal disease improved after treatment with tumor necrosis factor alpha blockade, however complications of existing airway disease led to recurrent hospitalizations and eventually death.