Enzyme-linked immunospot assay responses to early secretory antigenic target 6, culture filtrate protein 10, and purified protein derivative among children with tuberculosis: implications for diagnosis and monitoring of therapy

Clin Infect Dis. 2005 May 1;40(9):1301-8. doi: 10.1086/429245. Epub 2005 Mar 23.


Background: The ability to detect tuberculosis-specific lymphocytes by enzyme-linked immunospot (ELISPOT) assay may have important implications for the diagnosis and monitoring of tuberculosis in children, for which routine methods lack sensitivity. We conducted a study to determine the presence and time course of ELISPOT responses in children with tuberculosis.

Methods: Blood samples were obtained from children with a clinical diagnosis of tuberculosis, and interferon-gamma ELISPOT assays were performed using purified protein derivative (PPD), early secretory antigenic target 6 (ESAT-6), and culture filtrate protein 10 (CFP10) as stimulants. A subset of children were retested after 1, 3, and 6 months of therapy.

Results: Detectable responses to ESAT-6 or CFP10 were found in 49 of 70 children with clinical tuberculosis but were more frequently found in those with culture-proven disease (P = .05). The number of subjects with responses to PPD increased after 1 month of therapy (P = .0004) and decreased at 3 and 6 months.

Conclusion: Tuberculosis-specific ELISPOT testing is a promising tool that should be evaluated as a potential diagnostic test for childhood tuberculosis. We caution against the use of an early decrease in response as a marker of successful antituberculous chemotherapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Bacterial / immunology*
  • Antitubercular Agents / therapeutic use*
  • Bacterial Proteins / immunology*
  • Child
  • Child, Preschool
  • Drug Administration Schedule
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Sensitivity and Specificity
  • Tuberculin / immunology*
  • Tuberculosis / diagnosis*
  • Tuberculosis / drug therapy*


  • Antigens, Bacterial
  • Antitubercular Agents
  • Bacterial Proteins
  • CFP-10 protein, Mycobacterium tuberculosis
  • ESAT-6 protein, Mycobacterium tuberculosis
  • Tuberculin