Relapsing polychondritis with p-ANCA associated vasculitis: Which triggers the other?

Relapsing polychondritis(RP) is a rare autoimmune disease with chronic inflammatory/destructive lesions of the cartilaginous tissues. In one third of the cases it is associated with other autoimmune disorders, mostly with anti-neutrophil cytoplasmic antibody(ANCA) associated vasculitis(AAV). We report three cases of RP with p-ANCA positive AAV. In the first patient RP developed 1.5 years after the onset of AAV. In the others the signs of RP were present before the onset of severe crescent glomerulonephritis. Patients responded well on steroid and cyclophosphamide. In dialysis dependent cases plasmapheresis was also used successfully. During the 2 and 1.5 years of follow up, they were symptom-free, and had stable glomerular filtration rate. The first patient died after four years of follow-up due to the complications of sudden unset pancytopenia,which raises the possibility of associated hemophagocytic syndrome. In the setting of RP or AAV physicians should always be aware of the possibility of sudden or insidious appearance of the other disease.