title: ["Catastrophic systemic lupus erythematosus" with Rosai-Dorfman sinus histiocytosis. Successful treatment with anti-CD20/rutuximab].
abstract: METHODS
  A 59-year old woman was admitted with a four-month history of polyarthritis, myalgias and photosensitivity insufficiently responsive to methotrexate, corticosteroids and azathioprin. On physical examination she presented with symmetric ankle edema, polyserositis, petechial bleeding and swelling of cervical, axillary and inguinal lymph nodes.
  
  
  METHODS
  Laboratory analysis revealed a trilinear cytopenia without signs of hemolysis. Acute phase proteins were elevated. Furthermore antinuclear antibodies, anti-phospholipid IgM antibodies, hypocomplementemia, a spurious IgGkappa paraprotein were noted. CT scans confirmed lymphadenopathy and revealed a pleural and pericardial effusion. Bone marrow biopsy showed marked hypercellularity and polyclonal plasmocytosis. Based on these findings systemic lupus erythematosus was initially suspected. However when abdominal MRI showed a retroperitoneal mass, an extensive histological workup, which also included lymph nodes and spleen, revealed numerous plasma cells and histiocytes in dilated sinuses, diagnostic of Rosai-Dorfman sinus histiocytosis.
  
  
  METHODS
  High dose corticosteroids, intravenous gamma-globulin and repeated courses of cyclophosphamide failed to improve the pancytopenia, as did splenectomy. The patient was given the anti-CD20 monoclonal antibody Rituximab and all signs and symptoms improved dramatically. 18 months after the last treatment, the patient is in complete clinical and hematological remission.
  
  
  CONCLUSIONS
  Sinus histiocytosis of Rosai/Dorfman can be associated with or mimic severe SLE. Rituximab, an anti-CD20 monoclonal antibody, may improve the antibody-mediated pathogenetic mechanism underlying both entities.
authors.affiliation: Medizinische Klinik, Abteilung, Rheumatologie und Klinische Immunologie, Universitätsklinikum Freiburg. petschner@mm61.ukl.uni-freiburg.de
authors.forename: F
authors.initials: F
authors.lastname: Petschner
authors.forename: U A
authors.initials: UA
authors.lastname: Walker
authors.forename: A
authors.initials: A
authors.lastname: Schmitt-Gräff
authors.forename: M
authors.initials: M
authors.lastname: Uhl
authors.forename: H H
authors.initials: HH
authors.lastname: Peter
mesh_terms: D000209:Acute-Phase Proteins / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D003937:Diagnosis, Differential; D005260:Female; D006644:Histiocytes / Q000473:pathology; D015618:Histiocytosis, Sinus / Q000150:complications* / Q000175:diagnosis / Q000276:immunology / Q000628:therapy; D006801:Humans; D007150:Immunohistochemistry; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000175:diagnosis* / Q000276:immunology / Q000628:therapy; D008198:Lymph Nodes / Q000473:pathology; D008875:Middle Aged; D000069283:Rituximab; D013997:Time Factors; D014057:Tomography, X-Ray Computed
chemical_list: D000209:Acute-Phase Proteins; D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000970:Antineoplastic Agents; D000069283:Rituximab