Latent tuberculosis infection in transplant candidates: a systematic review and meta-analysis on TST and IGRA

Introduction: The diagnostic accuracy of interferon-gamma release assays (IGRAs) and the tuberculin skin test (TST) for latent tuberculosis infection (LTBI) in transplant candidates is uncertain. Methods: Pubmed, Embase and Cochrane library were searched to identify relevant studies. Quality of included studies was assessed with RevMan5 software (via GUADAS2 checklist). Accuracy measures of IGRAs and TST assays (sensitivity, specificity and others) were pooled with random effects model. Data were analyzed by STATA and Meta-DiSc. Results: Twenty-eight studies were selected for full review, and 16 were included in the final analysis. The pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) for TST were 46% [95% confidence interval (CI) 38–54%], 86% (95% CI 75–93%), 46.3% (95% CI 40–52), 88.7% (95% CI 87–89), 3.3 (95% CI 1.6–6.4), 0.63 (95% CI 0.52–0.77) and 5 (95% CI 2–12), respectively. For QFT-G, the pooled sensitivity, specificity, PPV, NPV, PLR, NLR, and DOR were 58% (95% CI 41–73%), 89% (95% CI 77–95%), 72.7% (95% CI 68–76), 80.6% (95% CI 78–82), 5.3 (95% CI 2.0–14.0), 0.47 (95% CI 0.30–0.75) and 11 (95% CI 3–46), respectively. Likewise, for T-SPOT.TB, the pooled sensitivity, specificity, PPV, NPV, PLR, NLR, and DOR were 55% (95% CI 40–70%), 92% (95% CI 87–95%), 60.4% (95% CI 47–72), 90.2% (95% CI 86–92), 6.7 (95% CI 4.0–11.1), 0.52 (95% CI 0.31–0.85) and 16 (95% CI 7–37), respectively. Conclusions: IGRAs were more sensitive and specific than the TST with regard to the diagnosis of LTBI in the transplant candidates. They have added value and can be complementary to TST.