title: A case of microscopic polyangiitis following mycoplasma infection in a patient with MPO-ANCA positive pulmonary fibrosis.
abstract: BACKGROUND
  Microscopic polyangiitis is a vasculitic disease that may result in a pulmonary renal syndrome. Anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis is strongly associated with infection.
  
  
  METHODS
  We describe a case of microscopic polyangiitis that developed in a patient with MPO-ANCA positive pulmonary fibrosis following infection with mycoplasma. A renal biopsy was undertaken following the detection of microscopic hematuria during follow-up but no abnormal findings were evident. The MPO-ANCA titer increased following infection with mycoplasma pneumonia and a second renal biopsy demonstrated crescentic glomerulonephritis. The degree of pulmonary fibrosis was unaffected.
  
  
  CONCLUSIONS
  The present case suggests that the mycoplasma infection triggered the elevation of MPO-ANCA titer and provoked glomerulonephritis in a patient with MPO-ANCA positive IPF. This case indicates the importance of testing for MPO-ANCA at the time of initial diagnosis, performing urinalysis and examining the urine sediment during follow-up and being alert to the potential onset of vasculitis in cases of pulmonary fibrosis.
authors.affiliation: Department of Respiratory Medicine, Cellular Transplantation Biology, Kanazawa University Hospital, Ishikawa, Japan. murakami@med3.m.kanazawa-u.ac.jp
authors.forename: Hazuki
authors.initials: H
authors.lastname: Takato
authors.forename: Masahide
authors.initials: M
authors.lastname: Yasui
authors.forename: Yuko
authors.initials: Y
authors.lastname: Waseda
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Sakai
authors.forename: Takashi
authors.initials: T
authors.lastname: Wada
authors.forename: Masaki
authors.initials: M
authors.lastname: Fujimura
mesh_terms: D000890:Anti-Infective Agents / Q000627:therapeutic use; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology*; D005260:Female; D005921:Glomerulonephritis / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology / Q000473:pathology; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D055953:Microscopic Polyangiitis / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology* / Q000276:immunology; D008875:Middle Aged; D009175:Mycoplasma Infections / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology; D011658:Pulmonary Fibrosis / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000276:immunology; D011859:Radiography; D016896:Treatment Outcome
chemical_list: D000890:Anti-Infective Agents; D019268:Antibodies, Antineutrophil Cytoplasmic; D007166:Immunosuppressive Agents