title: High-sensitive and rapid detection of Mycobacterium tuberculosis infection by IFN-gamma release assay among HIV-infected individuals in BCG-vaccinated area.
abstract: BACKGROUND
  An accurate test for Mycobacterium tuberculosis infection is urgently needed in immunosuppressed populations. The aim of this study was to investigate the diagnostic power of enzyme-linked immunospot (ELISPOT)-based IFN-gamma release assay in detecting active and latent tuberculosis in HIV-infected population in bacillus Calmette-Guerin (BCG)-vaccinated area. A total of 100 HIV-infected individuals including 32 active tuberculosis patients were recruited. An ELISPOT-based IFN-gamma release assay, T-SPOT.TB, was used to evaluate the M. tuberculosis ESAT-6 and CFP-10 specific IFN-gamma response. Tuberculin skin test (TST) was performed for all recruited subjects.
  
  
  RESULTS
  The subjects were divided into group HIV+ATB (HIV-infected individuals with active tuberculosis, n = 32), group HIV+LTB (HIV-infected individuals with positive results of T-SPOT.TB assay, n = 46) and group HIV only (HIV-infected individuals with negative results of T-SPOT.TB assay and without evidence of tuberculosis infection, n = 22). In group HIV+ATB and HIV+LTB, T-SPOT.TB positive rate in subjects with TST <5 mm were 50% (16/32) and 41.3% (19/46), respectively. Individuals in group HIV+ATB and HIV+LTB with CD4+ T cells <500/microl, T-SPOT.TB showed a higher sensitivity than TST (64.5% vs. 22.6% and 62.2% vs. 29.7%, respectively, both P < 0.0001). In addition, the sensitivity of T-SPOT.TB assay in group HIV+ATB increased to >85% in patients with TB treatment for less than 1 month and CD4+ T cells > or = 200/microl, while for patients treated for more than 3 months and CD4+ T cells <200/microl, the sensitivity was decreased to only 33.3%. Furthermore, the results could be generated by T-SPOT.TB assay within 24 hours, which was more rapid than TST with 48-72 hours.
  
  
  CONCLUSIONS
  ELISPOT-based IFN-gamma release assay is more sensitive and rapid for the diagnosis of TB infection in Chinese HIV-infected individuals with history of BCG vaccination, and could be an effective tool for guiding preventive treatment with isoniazid in latently infected people and for TB control in China.
authors.affiliation: Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai 200040, PR China. jiangweimin2004@163.com
authors.forename: Weimin
authors.initials: W
authors.lastname: Jiang
authors.forename: Lingyun
authors.initials: L
authors.lastname: Shao
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
authors.forename: Chengyan
authors.initials: C
authors.lastname: Meng
authors.forename: Yunya
authors.initials: Y
authors.lastname: Xu
authors.forename: Lingli
authors.initials: L
authors.lastname: Huang
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Xinhua
authors.initials: X
authors.lastname: Weng
authors.forename: Wenhong
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D001500:BCG Vaccine / Q000008:administration & dosage; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D002681:China; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006678:HIV / Q000276:immunology* / Q000472:pathogenicity; D015658:HIV Infections / Q000150:complications / Q000276:immunology* / Q000382:microbiology; D006801:Humans; D016867:Immunocompromised Host / Q000276:immunology*; D007371:Interferon-gamma / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology* / Q000472:pathogenicity; D011237:Predictive Value of Tests; D012882:Skin Tests; D014376:Tuberculosis / Q000150:complications / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D014611:Vaccination; D014774:Virulence
chemical_list: D001500:BCG Vaccine; D007371:Interferon-gamma