Possible intrinsic association of anti-neutrophil cytoplasmic antibody-associated vasculitis coexisting with multiple myeloma.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a life-threatening condition that causes renal failure. Multiple myeloma (MM) is a malignant proliferation of monoclonal plasma cells in the blood that can also cause renal failure. The two diseases have high morbidity and mortality rates in the elderly, with a poor prognosis. A 64-year-old female presented to Xinqiao Hospital (Chonqing, China) with fatigue and a poor appetite that had been apparent for 6 weeks. Laboratory tests revealed a serum creatinine level of 10.31 mg/dl, a cytoplasmic ANCA titer of 1:10, a positive result for myeloperoxidase and a serum globulin level of 3.96 g/dl. A renal biopsy revealed crescent glomerulonephritis, combined with the rapid progression of renal function. Based on these observations (ANCA titer, crescent glomerulonephritis and rapid progression of renal function) a diagnosis of AAV was established. MM was confirmed by serum immunofixation electrophoresis combined with bone marrow aspiration. The present study discusses what is, to the best of our knowledge, the first case of AAV coexisting with MM in order to highlight it as a clinical concern.