The Dilemma of Vasculitis: A Rare Overlap of ANCA-Associated Vasculitis and Behçet-like Features with IgA Nephropathy

Abstract

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is an uncommon autoimmune small-vessel condition that may coexist with other immune-mediated disorders, resulting in intricate clinical manifestations. We present a 39-year-old female with poorly managed diabetes mellitus for 16 years, who had non-healing ulcers on feet, anterior chest discomfort, and recurrent oral ulcers. Laboratory investigations indicated increased ESR and CRP levels, urine routine showed proteinuria and glucosuria,c-ANCAby Immunofluorescence positive (PR3-ANCA 153 U/mL),HLA-B51 and pathergy positivity. Renal biopsy confirmed IgA nephropathy, sternal biopsy revealed non-granulomatous small-vessel vasculitis, and CT thorax showed cavitary pulmonary nodules. A diagnosis of overlapping vasculitis, with ANCA-associated vasculitis and Behçet-like characteristics with IgA nephropathy was established. The patient received intravenous pulse methylprednisolone, followed by oral corticosteroids, azathioprine, and colchicineresulting in ulcer healing, normalization of inflammatory markers, and radiographic resolution with stable renal function at six months. Timely diagnosis and personalized immunosuppressive treatment resulted in a positive outcome in this uncommon overlap vasculitis manifestation.