Risk and impact of tuberculosis in patients with chronic myeloid leukemia: A nationwide population-based study in Taiwan

The relationship between chronicmyeloid leukemia (CML) and tuberculosis (TB) has not been determined.We conducted a national survey including 1,082 CML patients identified fromthe Taiwan National Health Insurance database covering a period between 1998 and 2011; thematched non-exposed cohort included 10,820 subjects without CML that werematched for age, sex and comorbidities. The impact of TB was measured by the overall mortality, and the risk factors were identified by a multivariate Cox proportional hazards model. We found the risk of TB was higher in the CML cohort, with an adjusted hazard ratio (aHR) of 3.76 (p50.001) for both pulmonary (aHR 3.23, p < 0.001) and extrapulmonary (aHR 9.77, p50.001) TB. Specific risk factors were: aged ≥60 (aHR 3.24, p50.022), beingmale (aHR 13.49, p50.012), receiving stem cell transplantation (aHR 10.50, p50.001) and interferon-a therapy (aHR 3.34, p50.011). CML patients with TB had a higher mortality rate than those without (aHR 2.04, p50.043).We conclude that the incidence of TB is significantly higher in CML patients of male sex, aged≥60, having received either stem cell transplantation or interferon-a treatment. Careful screening strategies for TB should be considered for CML patients with high risk of the infection.