Clinical Presentation, Risk Factors and Outcome of Non-Tuberculous Mycobacteria Infection in Hematopoietic Stem-Cell Transplantation: A Multinational Case-Control Study

Abstract Background The clinical and microbiological features of infection due to non-tuberculous mycobacteria (NTM) after hematopoietic stem-cell transplantation (HSCT) remain poorly understood. Methods We performed a retrospective, multinational case-control study that included HSCT recipients (≥12 years) diagnosed with NTM disease between January 2008 and December 2018. Controls were HSCT recipients with no evidence of NTM disease, matched (1:2 ratio) by participating center and post-transplant survival. Logistic regression on matched pairs was used to investigate risk factors for NTM disease. Results We included 25 cases of NTM disease. The most common HSCT type was allogeneic from unrelated donor (72.0%) after myeloablative conditioning (76.0%). Predominant hematological conditions were acute myelogenous leukemia (28.0%) and myelodysplastic syndrome (24.0%). Most patients (88.0%) had previously received immunosuppressive therapy. The most common species identified were Mycobacterium avium complex (64.0%) and rapidly growing mycobacteria (20.0%). Most patients (68.0%) had pulmonary disease. All but one received antimycobacterial therapy for a median of 267.5 days. Macrolides (83.3%), rifamycins (58.3%) and ethambutol (62.5%) were the most commonly used drugs. Four patients (16.7%) developed adverse events requiring therapy discontinuation. All-cause and attributable mortality rates were 28.0% and 4.0%, respectively. One patient experienced relapse after 464 days. Diagnosis of a non-NTM infection (adjusted odds ratio [aOR]: 3.11; 95% confidence interval [95% CI]: 1.25–7.78) and corticosteroid therapy (aOR: 2.88; 95% CI: 1.16–7.17), both within the previous 90 days, were associated with NTM disease. Conclusions NTM disease is a serious complication among heavily immunocompromised HSCT recipients associated with prior non-NTM infection and corticosteroid therapy.