Mycobacterial infections in adult patients with hematological malignancy

We retrospectively analyzed the clinical and microbiological characteristics of adult patients with hematological malignancy and nontuberculous mycobacteria (NTM) infections from 2001 to 2010. During the study period, 50 patients with hematological malignancy and tuberculosis (TB) were also evaluated. Among 2,846 patients with hematological malignancy, 34 (1.2%) patients had NTM infections. Mycobacterium avium-intracellulare complex (13 patients, 38%) was the most commonly isolated species, followed by M. abscessus (21%), M. fortuitum (18%), and M. kansasii (18%). Twenty-six patients had pulmonary NTM infection and eight patients had disseminated disease. Neutropenia was more frequently encountered among patients with disseminated NTM disease (p = 0.007) at diagnosis than among patients with pulmonary disease only. Twenty-five (74%) patients received adequate initial antibiotic treatment. Five of the 34 patients died within 30 days after diagnosis. Cox regression multivariate analysis showed that chronic kidney disease (p = 0.017) and neutropenia at diagnosis (p = 0.032) were independent prognostic factors of NTM infection in patients with hematological malignancy. Patients with NTM infection had higher absolute neutrophil counts at diagnosis (p = 0.003) and a higher 30-day mortality rate (15% vs. 2%, p = 0.025) than TB patients. Hematological patients with chronic kidney disease and febrile neutropenia who developed NTM infection had significant worse prognosis than patients with TB infection.