Serodiagnosis of Mycobacterium avium-complex pulmonary disease using an enzyme immunoassay kit

Am J Respir Crit Care Med. 2008 Apr 1;177(7):793-7. doi: 10.1164/rccm.200705-771OC. Epub 2007 Dec 13.


Rationale: The diagnosis of Mycobacterium avium-complex pulmonary disease (MAC-PD) and/or its discrimination from pulmonary tuberculosis (TB) is sometimes complicated and time consuming.

Objectives: We investigated in a six-institution multicenter study whether a serologic test based on an enzyme immunoassay (EIA) kit was useful for diagnosing MAC-PD and for distinguishing it from other lung diseases.

Methods: An EIA kit detecting serum IgA antibody to glycopeptidolipid core antigen specific for MAC was developed. Antibody levels were measured in sera from 70 patients with MAC-PD, 18 with MAC contamination, 37 with pulmonary TB, 45 with other lung diseases, and 76 healthy subjects.

Measurements and main results: Significantly higher serum IgA antibody levels were detected in patients with MAC-PD than in the other groups (P < 0.0001). Setting the cutoff point at 0.7 U/ml resulted in a sensitivity and specificity of the kit for diagnosing MAC-PD of 84.3 and 100%, respectively. Significantly higher antibody levels were also found in patients with nodular-bronchiectatic disease compared with fibrocavitary disease in MAC-PD (P < 0.05). There was a positive correlation between the extent of disease on chest computed tomography scans and the levels of antibody (r = 0.43, P < 0.05) in patients with MAC-PD.

Conclusions: The EIA kit is useful for the rapid diagnosis of MAC-PD and for differentiating MAC-PD from pulmonary TB and, if validated by studies in other populations, could find wide application in clinical practice.

Publication types

  • Comparative Study
  • Evaluation Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Case-Control Studies
  • Diagnosis, Differential
  • Female
  • Humans
  • Immunoenzyme Techniques*
  • Lung Diseases / diagnosis*
  • Lung Diseases / microbiology
  • Male
  • Middle Aged
  • Mycobacterium avium-intracellulare Infection / diagnosis*
  • ROC Curve
  • Reagent Kits, Diagnostic
  • Sensitivity and Specificity
  • Tuberculosis, Pulmonary / diagnosis


  • Reagent Kits, Diagnostic