title: Antisynthetase syndrome: An under-recognized cause of interstitial lung disease.
abstract: BACKGROUND
  Antisynthetase syndrome (AS) is an uncommon and under-recognised connective tissue disease characterized by the presence of antibodies to anti-aminoacyl t-RNA synthetase along with features of interstitial lung disease (ILD), myositis and arthritis. The aim of the current study is to describe our experience with management of AS.
  
  
  METHODS
  This was a 2-year (2013-2014) retrospective analysis of patients diagnosed with anti-Jo-1-related AS. The presence of anti-Jo-1 antibody was tested by the immunoblot assay. All patients underwent high-resolution computed tomography of the chest, transthoracic echocardiography and evaluation for inflammatory myositis. Transbronchial lung biopsies and muscle biopsies were obtained when clinically indicated.
  
  
  RESULTS
  Nine patients (mean age: 43.8 years) were diagnosed with anti-Jo-1-related AS. The median duration of symptoms before diagnosis of AS was 6 months. All patients were negative for antinuclear antibodies by indirect immunofluorescence. The prevalence of ILD, myositis and arthritis at presentation was 100%, 77.8% and 55.6%, respectively. The most common ILD pattern was non-specific interstitial pneumonia (n = 6) followed by organizing pneumonia (n = 2) and usual interstitial pneumonia (n = 1). ILD was the sole manifestation in two patients and was subclinical in two patients. Six patients had pleuropericardial effusions, three patients had pulmonary artery hypertension and two patients had venous thromboembolism. Eight of the nine patients improved after treatment with steroids and other immunosuppressants.
  
  
  CONCLUSIONS
  Antisynthetase syndrome is an important and a treatable cause of ILD. Strong clinical suspicion is needed to achieve an early diagnosis.
authors.affiliation: Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, Haryana and Punjab, India.
authors.forename: Venkata Nagarjuna
authors.initials: VN
authors.lastname: Maturu
authors.affiliation: Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, Haryana and Punjab, India.
authors.forename: Arjun
authors.initials: A
authors.lastname: Lakshman
authors.affiliation: Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, Haryana and Punjab, India.
authors.forename: Amanjit
authors.initials: A
authors.lastname: Bal
authors.affiliation: Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, Haryana and Punjab, India.
authors.forename: Varun
authors.initials: V
authors.lastname: Dhir
authors.affiliation: Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, Haryana and Punjab, India.
authors.forename: Aman
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Department of Radiodiagnosis, Postgraduate Institute of Medical Education and Research, Chandigarh, Haryana and Punjab, India.
authors.forename: Mandeep
authors.initials: M
authors.lastname: Garg
authors.affiliation: Department of Immunopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, Haryana and Punjab, India.
authors.forename: Biman
authors.initials: B
authors.lastname: Saikia
authors.affiliation: Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, Haryana and Punjab, India.
authors.forename: Ritesh
authors.initials: R
authors.lastname: Agarwal
keywords: Antisynthetase syndrome; anti-Jo-1 antibody; diffuse parenchymal lung disease; inflammatory myositis; interstitial lung disease; non-specific interstitial pneumonia