Beswick J, et al. - Researchers planned this study to determine the incidence and risk factors for Nontuberculous mycobacteria (NTM) infection after allogeneic hematopoietic stem cell transplant (HCT). They identified an association of severe chronic graft versus host disease (cGVHD) and CMV (cytomegalovirus) viremia with increased risk, permitting risk stratification.

Methods

• Researchers performed a retrospective cohort study; the study included all patients who underwent allogeneic HCT from 2001 to 2013 at their institution.
• Identification of patients developing significant NTM infection (NTM disease) was performed.
• They used multivariable modeling to identify risk factors for NTM disease, and constructed a risk score model to identify high-risk patients.

Results

• Of 1,097 allogeneic HCT patients, NTM was isolated from 45 (4.1%), and NTM disease was observed in 30 (2.7%) (28 (93.3%) exclusively pulmonary, 2 (6.7%) pulmonary plus another site).
• Competing risk analysis indicated NTM infection incidence of 2.8% at 5 years (95%CI, 1.9-4.0%).
• In this study, the median (range) time to diagnosis was 343 (19-1,967) days.
• Fine-Gray proportional hazards modeling indicated that only global severity of chronic graft versus host disease (cGVHD) (HR=1.99, 95%CI [1.12-3.53], p=0.019,) and CMV viremia (HR=5.77, 95%CI [1.71-19.45], p=0.004,) were markedly associated with NTM disease.
• Using these variables, researchers calculated a risk score (one point for CMV viremia or moderate cGVHD, 2 points for severe cGVHD).
• The score classified patients into following groups: low risk (0-1 points, n=820 (77.3%), three-year NTM risk 1.2%), intermediate risk (2 points, n=161 (15.4%), three-year NTM risk 7.1%), and high risk (3 points, n=56 (5.4%), three-year NTM risk 14.3%).