[A case of progressive systemic sclerosis with crescentic glomerulonephritis associated with myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) and anti-glomerular basement membrane antibody (anti-GBM Ab)].

A 42-year-old female with progressive systemic sclerosis (PSS) developed rapidly progressive renal insufficiency. Renal pathology revealed crescentic glomerulonephritis (CrGN) without mucoid intimal proliferation of the interlobular arteries and fibrinoid necrosis of the afferent arterioles. Immunofluorescent micrography showed linear deposition of IgG along the glomerular capillary wall. Not only anti-glomerular basement membrane antibody (anti-GBM Ab), but also myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) were simultaneously detected by an enzymelinked immunosorbent assay (ELISA). She did not develop pulmonary hemorrhage. These findings were compatible with ANCA-related vasculitis and anti-GBM Ab nephritis. Laboratory findings showed rapid elevation of serum creatinine level (over 6.0mg/dl), a high titer of MPO-ANCA (660.7 ELISA unit/ml) and anti-GBM Ab (409 units). Therefore, she was started on methylprednisolone pulse therapy and temporary hemodialysis. After immunosuppressive therapy, both antibodies titers had fallen to within the normal range. However, end-stage renal failure did not improve and maintenance hemodialysis was introduced. Recently, six patients of PSS with MPO-ANCA were first reported in Japan. These autoantibodies detected in this case strongly suggested that there may be associations between anti-GBM Ab nephritis and ANCA-related vasculitis and PSS.