ANCA-Associated Crescent Glomerulonephritis Related To Systemic Sclerosis: A Case Report

Resumo

Systemic sclerosis is the collagenosis with the highest mortality rate, since multiorgan damage may occur, besides the characteristic skin involvement. The annual incidence is estimated to range from 8 to 56 cases per million inhabitants, with a predominance in women. Renal involvement occurs in approximately 50% of cases through various possible pathogenic mechanisms. We present the case of a 42‑year‑old woman undergoing immunosuppressive treatment for pulmonary involvement of systemic sclerosis with cyclophosphamide, who developed acute renal injury requiring dialysis. High titers of antineutrophil cytoplasmic antibodies (ANCA), with antibodies against myeloperoxidase, associated with a glomerular crescent histological pattern and a pauci‑immune pattern in immunofluorescence, indicated renal involvement by ANCA vasculitis in the context of high‑intensity immunosuppressive therapy for systemic sclerosis. After controlling infection and hemorrhagic complications related to the renal biopsy, pulse therapy with methylprednisolone and rituximab was initiated, leading to improved renal function and the discontinuation of dialysis therapy. The overlap between ANCA vasculitis and systemic sclerosis is challenging to recognize due to the rarity of this severe form of autoimmunity and the need to rule out other possible diagnoses in this context, such as scleroderma renal crisis. Special attention should be given to the response to the chosen immunosuppressive regimen, given the possibility of disease activation despite ongoing therapy.