title: Successful Immunosuppressive Treatment of Mixed Connective Tissue Disease Complicated by Microscopic Polyangiitis.
abstract: Mixed connective tissue disease (MCTD) is characterized by a combination of clinical features of systemic lupus erythematosus, systemic sclerosis, and polymyositis with elevated antibodies to U1 small nuclear ribonucleoprotein (U1-RNP). MCTD is often accompanied by interstitial lung disease as pulmonary involvement. On the other hand, microscopic polyangiitis (MPA) is a systemic autoimmune disease characterized by the inflammation of small vessels (arterioles, capillaries, and venules) mainly affecting the lung and kidney. MPA is associated with elevated serum anti-neutrophil cytoplasmic antibody (ANCA). Complication of MPA in patients with MCTD is rare. So far, only nine case reports of MCTD complicated by MPA with serum myeloperoxidase-specific ANCA (MPO-ANCA) are available. Here, we describe a 64-year-old male suffering from MCTD with MPA. The patient developed interstitial pneumonia with alveolar hemorrhage accompanied by myositis, scleroderma, and elevated anti-U1-RNP antibody and MPO-ANCA levels with substantial systemic inflammation. Strong immunosuppressive therapy (corticosteroid, intravenous immunoglobulin, and cyclosporine A) ameliorated the myositis, interstitial lung disease, and inflammation, with the decrease of MPO-ANCA levels, despite that severe lung complications are often associated with poor outcomes. In conclusion, MCTD may be accompanied by MPA with alveolar hemorrhage. Severe lung complications may indicate a poor outcome, and therefore prompt immunosuppressive treatment should be performed in such patients.
authors.affiliation: Department of Gastroenterology and Rheumatology, Fukushima Medical University School of Medicine.
authors.forename: Shuzo
authors.initials: S
authors.lastname: Sato
authors.forename: Makiko
authors.initials: M
authors.lastname: Yashiro
authors.forename: Naoki
authors.initials: N
authors.lastname: Matsuoka
authors.forename: Manabu
authors.initials: M
authors.lastname: Uematsu
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Asano
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Ohira
mesh_terms: D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D018450:Disease Progression; D005269:Femur / Q000000981:diagnostic imaging; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008264:Macrophages / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D055953:Microscopic Polyangiitis / Q000150:complications* / Q000188:drug therapy*; D008875:Middle Aged; D008947:Mixed Connective Tissue Disease / Q000150:complications* / Q000188:drug therapy*; D014057:Tomography, X-Ray Computed
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D007166:Immunosuppressive Agents