Mycobacterial infections in adult recipients of allogeneic hematopoietic stem cell transplantation: A cohort study in a high endemic area

Background: Mycobacterial infections are important and potentially life-threatening complications after organ transplantations. Notably, for the recipients of allogeneic hematopoietic stem cell transplantation (HSCT), there are a few supporting results to explore post-transplant mycobacterial infections. Taiwan is a high endemic area of the infection. We aim to investigate the incidence, risk factors, and survival of post-transplant mycobacterial infections, including mycobacterium tuberculosis (MTB) and non-tuberculous mycobacterium (NTM). Methods: We included 422 adult patients undergoing allogeneic HSCT at an Asian tertiary medical center between January 2003 and December 2014. A total 26 subjects developed post-transplant mycobacterial infections. Risk factors, clinical features, and survival for post-transplant mycobacterial infections were collected and analyzed. Results: Post-transplant mycobacterial infections occurred in 26 (6.2%) of 422 HSCT patients. Two-year cumulative incidences in MTB and NTM were 1.4% and 5.4%. In the multivariate analysis, being age >45 years (adjusted HR 2.21, 95% CI 1.01–4.83) and extensive chronic graft-versus-host disease (cGVHD) (adjusted HR 4.95, 95% CI 2.14–11.46) were identified as independent risk factors of infections. There was a trend as a risk factors in relapsed patients (P = 0.088). For patients with cGVHD, there was a significant difference of post-transplant survival between mycobacterial infections and none (P = 0.036). Pneumonia contributed most to mortality (n = 11, 42.3%). Conclusion: Mycobacterial infections are worth to note in a high endemic area. Once a high-risk group is identified, much effort is required to target new approaches for prevention, early detection and treatment of infections. Keywords: Hematopoietic stem cell transplantation, Mycobacterial infections, Mycobacterium tuberculosis, Non-tuberculous mycobacterium, Graft-versus-host disease