Interferon-γ release assays do not identify more children with active tuberculosis than the tuberculin skin test

Abstract

Data are lacking on the performance of interferon-c release assays (IGRAs) in children. Although IGRAs are recommended for screening for latent tuberculosis infection (LTBI), many clinicians wish to employ them as a diagnostic test for active tuberculosis (TB). The objective of the present study was to compare the performance of the two commercially available IGRAs and the tuberculin skin test (TST) side-by-side in children with active TB and LTBI.In a prospective study, 209 children were investigated for active (n591) or latent TB (n5118). TST, QuantiFERON-TB Gold In-tube (QFG-IT; Cellestis, Carnegie, Australia) and T-SPOT.TB (Oxford Immunotec, Abingdon, UK) assays were simultaneously used.For culture-confirmed active TB, the sensitivity of the TST was 83%, compared with 80% for QFG-IT and 58% for T-SPOT.TB. IGRAs did not perform significantly better than TST, although QFG-IT was significantly better than T-SPOT.TB. The agreement between QFG-IT and T-SPOT.TB in culture-confirmed TB was poor at 66.7%. In LTBI, the agreement between QFG-IT and T-SPOT.TB was very good (92%) with moderate agreement between TST and T-SPOT.TB (75%) and QFG-IT and TST (77%).A negative interferon-c release assay should not dissuade paediatricians from diagnosing and treating presumed active tuberculosis. If used for diagnosis of latent tuberculosis infection, interferon-c release assays could significantly reduce the numbers of children receiving chemoprophylaxis. Very good concordance between both tests was found.

Interferon-γ release assays for the diagnosis of latentMycobacterium tuberculosisinfection: a systematic review and meta-analysis

“…In nine of these, TST positivity was significantly associated with BCG vaccination as an independent predictor in multivariate analysis [47,50,55,62,67,71,72,74,77] with odd ratios ranging between 3.8 (95% CI 1.0-13.9) [50] [35] GOLETTI [36] JAFARI [37] JAFARI [38] KAMPMANN [39] KANG [40] LEE [41] MARKOVA [42] WANG [43] DETJEN [26] DHEDA [34] GOLETTI [36] KAMPMANN [39] KANG [40] MARKOVA [42] odds for test positivity with M. tuberculosis exposure gradients, or using chest radiography lesions as a surrogate of prior exposure, the IGRAs associated better with exposure than the TST, irrespective of the setting's disease burden. Furthermore, there was generally a poor agreement between IGRAs and TST results (for k statistics, see table 3).…”

“…Association of IGRAs and the TST with MTB exposure and BCG vaccination 34 studies [27,39,45,] from a total of 18 different countries fulfilled the inclusion criteria for this section of the review. Four studies were from intermediate-burden countries (South Korea [55], Lithuania [59], Iran [63] and Turkey [72]) and three studies were from high-burden countries (India [56], South Africa [61] and Vietnam [65]).…”

“…Four studies were from intermediate-burden countries (South Korea [55], Lithuania [59], Iran [63] and Turkey [72]) and three studies were from high-burden countries (India [56], South Africa [61] and Vietnam [65]). Seven studies were based solely on paediatric cohorts [39,51,54,59,73,75] and three studies [47,57,61] included children in the study population.…”

“…NPV in patients with active tuberculosis 18 articles satisfied our inclusion criteria for evaluating the NPV; 13 assessed the NPV among confirmed tuberculosis cases [22,26,[34][35][36][37][38][39][40][41][42][43][44] and six assessed the prospective outcome in IGRA-negative individuals after an average of 2 yrs [19-22, 45, 46]. Among the studies in which the NPV was evaluated in patients with confirmed tuberculosis (387 tuberculosis cases with a valid T-SPOT1.TB result and 304 with valid QFT-G-IT result), the NPV varied greatly, irrespective of the IGRA used.…”

Diagnostic Value of T SPOT TB in Infant to 5-Year Old Children with Primary Forms of Tuberculosis

“…6, it can be seen that the children, who were in contact with tuberculous adults, have pronounced reactions to both the TST and the T SPOT TB, which once again shows that the close contact with a tuberculous patient affects the immunological reactivity of the body and results in more frequently in a disease [8][9][10]12].…”