Performance of the tuberculin skin test and interferon-gamma release assay for detection of tuberculosis infection in immunocompromised patients in a BCG-vaccinated population
Interferon-gamma release assay (IGRA) may improve diagnostic accuracy for latent tuberculosis infection (LTBI). This study compared the performance of the tuberculin skin test (TST) with that of IGRA for the diagnosis of LTBI in immunocompromised patients in an intermediate TB burden country where BCG vaccination is mandatory.
Methods: We conducted a retrospective observational study of patients given the TST and an IGRA, the QuantiFERON-TB Gold In-Tube (QFT-IT), at Severance Hospital, a tertiary hospital in South Korea, from December 2006 to May 2009.
Results: Of 211 patients who underwent TST and QFT-IT testing, 117 (55%) were classified as immunocompromised.
Significantly fewer immunocompromised than immunocompetent patients had positive TST results (10.3% vs. 27.7%, p 0.001), whereas the percentage of positive QFT-IT results was comparable for both groups (21.4% vs.
25.5%). However, indeterminate QFT-IT results were more frequent in immunocompromised than immunocompetent patients (21.4% vs.
9.6%, p 0.021). Agreement between the TST and QFT-IT was fair for the immunocompromised group (kappa = 0.38), but moderate agreement was observed for the immunocompetent group (kappa = 0.57).
Indeterminate QFT-IT results were associated with anaemia, lymphocytopenia, hypoproteinemia, and hypoalbuminemia.
Conclusion: In immunocompromised patients, the QFT-IT may be more sensitive than the TST for detection of LTBI, but it resulted in a considerable proportion of indeterminate results. Therefore, both tests may maximise the efficacy of screening for LTBI in immunocompromised patients.
Author: Eun Young KimJu Eun LimJi Ye JungJi Young SonKyung Jong LeeYoe Wun YoonByung Hoon ParkJin Wook MoonMoo Suk ParkYoung Sam KimSe Kyu KimJoon ChangYoung Ae Kang
Credits/Source: BMC Infectious Diseases 2009, 9:207
Published on: 2009-12-16
Copyright by the authors listed above - made available via BioMedCentral (Open Access). Please
make sure to read our disclaimer prior to contacting 7thSpace Interactive. To contact our editors, visit our online helpdesk. If you wish submit your own press release, click here.
Social Bookmarking
RETWEET This! | Digg this! | Post to del.icio.us | Post to Furl | Add to Netscape | Add to Yahoo! | Rojo
|
|
