A 43-year-old woman, with a 3-month history of
fatigue, anaemia and swollen lymph nodes, underwent biopsy of a lymph node, which revealed reactive
lymphadenopathy. Due to an increased serum
creatinine concentration and severe
proteinuria, a kidney biopsy was performed, which revealed diffuse, segmental, proliferative,
immune-complex glomerulonephritis with crescents. Electron microscopy showed tubulo-reticular structures within one endothelial cell. These were a typical clinical presentation and compatible histopathological findings for
systemic lupus erythematosus; however, the anti-
myeloperoxidase antineutrophil cytoplasmic antibody (MPO-
ANCA) level was extraordinarily high. In spite of treatment with intravenous
cyclophosphamide and
methylprednisolone pulse
therapy, the patient's kidney function declined. Starting
plasma exchange improved her renal function and removed MPO-ANCAs, which were suspected to play the major role in the pathogenesis of
glomerulonephritis. These findings indicate that in addition to
lupus nephritis, MPO-ANCAs may be involved in the pathogenesis of
glomerulonephritis and that the coincidence of
systemic lupus erythematosus and
ANCA may be responsible for the severe
clinical course in our patient.