Measurement of immunoglobulin G against Mycobacterial antigen A60 in patients with cystic fibrosis and lung infection due to Mycobacterium abscessus

Clin Infect Dis. 2005 Jan 1;40(1):58-66. doi: 10.1086/426442. Epub 2004 Dec 8.


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.

Conclusion: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / therapeutic use
  • Antigens, Bacterial / analysis*
  • Child
  • Cystic Fibrosis / immunology
  • Cystic Fibrosis / microbiology*
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Immunoglobulin G / analysis*
  • Kinetics
  • Lung Diseases / diagnosis
  • Lung Diseases / drug therapy
  • Lung Diseases / immunology
  • Lung Diseases / microbiology*
  • Mycobacterium / chemistry*
  • Mycobacterium / classification
  • Mycobacterium / immunology
  • Mycobacterium Infections / diagnosis
  • Mycobacterium Infections / drug therapy
  • Mycobacterium Infections / immunology
  • Mycobacterium Infections / microbiology*
  • Sensitivity and Specificity


  • Anti-Bacterial Agents
  • Antigens, Bacterial
  • Immunoglobulin G