Koenig KF Kalbermatter SA Menter T Mayr M Kiss D 2014 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. application/pdf https://sonar.ch/global/documents/92827 eng info:eu-repo/semantics/altIdentifier/doi/10.1159/000358557 info:eu-repo/semantics/altIdentifier/pmid/24575116 info:eu-repo/semantics/openAccess Case reports in nephrology and urology. - 2014 Lupus nephritis MPO-ANCA Plasma exchange Rapidly progressive lupus nephritis with extremely high levels of antineutrophil cytoplasmic antibodies. http://purl.org/coar/resource_type/c_6501