Extracapillary glomerulonephritis with anti-myeloperoxidase antibodies

BACKGROUND: Side-effects, including autoimmune disorders, are frequent with D-penicillamine therapy. Proteinuria is observed in 10% of the patients, o ften secondary to extramembranous glomerulopathy. Necrotizing extracapillar y glomerulonephritis is however exceptional. CASE REPORTS: Two patients with systemic sclerodermia were treated with D-p enicillamine for 7 and 14 years. Both developed necrotizing extracapillary glomerulonephritis with anti-myeloperoxidase antibodies (anti-MPO), associa ted with hemorrhagic alveolitis in one case. Partial regression of the rena l failure was obtained after withdrawal of D-penicillamine and combination treatment with prednisone and cyclophosphamide. DISCUSSION: Extracapillary glomerulonephritis or a lung-kidney syndrome are frequently associated with anti-MPO antineutrophil cytoplasm antibodies (A NCA). In systemic sclerodermia, the presence of anti-MPO appears to define a group of patients at risk of pauci-immune extracapillary glomerulonephrit is or a lung-kidney syndrome. In addition, the presence of ANCA in patients with renal failure would suggest extracapillary glomerulonephritis rather than sclerodermic microangiopathy. Development of extracapillary glomerulon ephritis with anti-MPO in patients who are taking D-penicillamine suggests that inductor mechanisms other than D-penicillamine are involved in the pat hogenesis of these glomerulopathies.