Validity of interferon-γ-release assays for the diagnosis of latent tuberculosis in haemodialysis patients

Abstract

Haemodialysis patients are at higher risk of developing active tuberculosis (TB) infection. However, tuberculin skin tests (TST) have limitations and the diagnostic usefulness of interferon-γ-release assays (IGRAs) remains unclear in immunocompromised hosts including haemodialysis patients. Haemodialysis patients were enrolled from a dialysis centre in Korea, an intermediate TB-burden country with a high bacille Calmette-Guérin (BCG) vaccination rate. The QuantiFERON-Gold TB In tube test (QFT) and the T-SPOT TB test (TSPOT) were performed, along with the TST. We stratified patients to low- and high-risk groups, according to the risk factors for latent TB. Association between each of the three diagnostic tests and the risk of latent TB was analysed. One hundred and sixty-seven patients were enrolled. The positive rates for the TST, the QFT and TSPOT were 23.5, 45.9 and 60.4%, respectively. Previous BCG vaccination increased the TST-positive rate in the low-risk group (OR 4.438), whereas it affected neither QFT nor TSPOT. The positive QFT rates were 41.2 and 62.5% in the low- and high-risk groups, respectively. The QFT was associated with the high-risk group (OR 2.578), whereas the TST was not. The positive TSPOT rates were 58.9 and 65.7% in the low- and high-risk groups, respectively. The frequency of indeterminate results was higher for the QFT (12.6%) compared with the TSPOT (4.8%). In conclusion, the IGRAs can be useful for the diagnosis of latent TB infection in haemodialysis patients.

Feasibility of the interferon-gamma enzyme-linked immunospot assay in chronic renal failure patients and immunocompetent subjects: a head-to-head comparison

“…24,25,38 Our study showed no significant difference between the ITR result frequency among study groups (CRF vs. IC), and that 5.4% of CRF patients had an ITR result with T-SPOT.TB test, which is consistent with previous reports. Pre-determined risk factors, such as longer duration of renal replacement therapy, total lymphocyte number were not affecting T-SPOT.TB test yielding as ITR in our study.…”

“…Passalent's, Chung's and Soysal's studies have shown that T-SPOT.TB assay detected LTBI more frequent than TST. [24][25][26] Conversely, TST positivity rates were more frequent than the T-SPOT.TB positivity in both groups in our study. Since BCG coverage was high (87%) in our study population, BCGvaccination may have caused false-positive TST results, whereas not influenced the T-SPOT.TB results.…”

“…10 ELISA-based IGRAs were found to be more sensitive than TST for diagnosing LTBI. 25,31 However, diagnostic performance of IGRAs was better in low TB endemic settings rather than Turkey. 10,32 Data regarding the performance of T-SPOT.TB test in high-risk groups as CRF patients is limited.…”

Interferon- release assays for the diagnosis of latent Mycobacterium tuberculosis infection: 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).…”

“…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.…”