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.