title: Measurement of immunoglobulin G against Mycobacterial antigen A60 in patients with cystic fibrosis and lung infection due to Mycobacterium abscessus.
abstract: BACKGROUND
  The diagnosis and prognosis of lung infections due to the emerging nontuberculous mycobacterium (NTM) Mycobacterium abscessus are difficult to establish in children with cystic fibrosis.
  
  
  METHODS
  We evaluated the usefulness of an enzyme-linked immunosorbent assay for detecting serum IgG antibodies against the ubiquitous mycobacterial antigen A60.
  
  
  RESULTS
  A total of 186 patients with cystic fibrosis (mean age+/-SD, 12.0+/-5.0 years) were studied, including 15 M. abscessus-positive patients who fulfilled American Thoracic Society (ATS) criteria for NTM infection (M. abscessus-infected patients), 7 M. abscessus-positive patients who did not fulfill ATS criteria, 20 patients positive for various other NTM who did not fulfill ATS criteria, and 144 NTM-negative control patients; mean IgG titers (+/-SD) for these 4 groups were 718+/-342 U, 193+/-113 U, 129+/-49 U, and 121+/-53 U, respectively (M. abscessus-infected patients vs. each of the other groups, P<.005). The A60 IgG test was both sensitive (approximately 87%) and specific (approximately 95%) if adapted cutoff values were used (150 U and 250 U for patients aged <or=10 years and patients aged >10 years, respectively) and correlated well with results of acid-fast bacilli smears.
  
  
  CONCLUSIONS
  Measurement of anti-A60 IgG may be useful for both the diagnosis and assessment of activity of M. abscessus lung infection in persons with cystic fibrosis.
authors.affiliation: Laboratoire de Microbiologie, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Ferroni
authors.forename: Isabelle
authors.initials: I
authors.lastname: Sermet-Gaudelus
authors.forename: Muriel
authors.initials: M
authors.lastname: Le Bourgeois
authors.forename: Catherine
authors.initials: C
authors.lastname: Pierre-Audigier
authors.forename: Catherine
authors.initials: C
authors.lastname: Offredo
authors.forename: Martin
authors.initials: M
authors.lastname: Rottman
authors.forename: Didier
authors.initials: D
authors.lastname: Guillemot
authors.forename: Claire
authors.initials: C
authors.lastname: Bernède
authors.forename: Véronique
authors.initials: V
authors.lastname: Vincent
authors.forename: Patrick
authors.initials: P
authors.lastname: Berche
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Gaillard
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000942:Antigens, Bacterial / Q000032:analysis*; D002648:Child; D003550:Cystic Fibrosis / Q000276:immunology / Q000382:microbiology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D007700:Kinetics; D008171:Lung Diseases / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology / Q000382:microbiology*; D009161:Mycobacterium / Q000737:chemistry* / Q000145:classification / Q000276:immunology; D009164:Mycobacterium Infections / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology / Q000382:microbiology*; D012680:Sensitivity and Specificity
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D007074:Immunoglobulin G