High prevalence of latent tuberculosis in hematopoietic stem cell transplant recipients: A First Report.

TB is an increasing health problem, and patients undergoing HSCT are more prone to develop tuberculosis. The aim of our study was to evaluate prevalence of latent tuberculosis in HSCT recipients. In this study, 84 patients (2 months to 18 years) who were candidates for HSCT at the referral hospital of Tehran Children's Medical Center were enrolled. The TST and the QFT-GIT test were performed in all 84 patients, simultaneously. LTBI was considered when one of the tests was positive. Overall, the prevalence of LTBI in HSCT recipients in our study was 12% (10 cases). TST induration ≥5 mm was seen in only three patients (3.5%). Eight patients (9.5%) had a positive result for IGRA test, and 11 of them (13%) had indeterminate QFT-GIT result. The agreement between the TST results (induration size ≥5 mm) and the QFT-GIT results was poor (kappa = 0.14). In conclusion, there was a high rate of discordance between TST and IGRA results with many more positive QFT-GIT tests. However, more studies are needed in this population to determine whether this discordance reflects true infection.