Management of Latent Tuberculosis Infection Based on T-SPOT.TB Assay in Patients with Hematological Malignancies

Patients with latent tuberculosis infection (LTBI) receiving chemotherapy for hematological malignancy (HM) are at high risk of developing active tuberculosis (TB) infection. The aim of this study is to show real-life data and results of the T-SPOT test and preventive isoniazid (INH) therapy in pre-chemotherapy LTBI screening in the HM patient group.

This retrospective study includes 209 HM patients who had T-SPOT test between 2016 and 2021 in Sultan 2. Abdulhamid Han Training and Research Hospital in Istanbul, Turkey.

The prevalence of LTBI was 26.8% in 209 patients (n=56). Preventive INH therapy was initiated in 82.1% (n=46) of 56 patients with LTBI. 23.9% (n=11) of the 46 patients who received preventive INH therapy were unable to complete the treatment. Nine patients died due to malignancy; one was lost to follow-up, and only one had to stop INH treatment due to elevated liver enzymes. Elevated liver enzymes occurred in 4 (8.7%) patients using INH, while gastrointestinal symptoms occurred in 3 (6.5%) patients. Active TB infection emerged in none of the T-SPOT positive or indeterminate individuals but in one HIV(+) patient in the T-SPOT negative group. The active TB infection incidence rate was 217 cases/100.000hab/year (95% CI, 29-748).

INH treatment was generally well tolerated, and very few serious drug-related side effects were observed. Although LTBI cannot be demonstrated in patients with HIV(+) HM who are scheduled for chemotherapy, these patients should be closely monitored for the development of active TB infection.