[Nontuberculous mycobacterial infections in patients with hematologic diseases]

Nontuberculous mycobacterial (NTM) infections are increasingly detected in immunocompromised patients with hematological disorders. Immunocompromised conditions caused by chemotherapy, hematopoietic stem cell transplantation (HSCT), and immunosuppressive therapies are associated with increased susceptibility to NTM infections. A recent nationwide cohort study in pediatric and adolescent/young adult patients has identified three distinct clinical patterns: (1) pulmonary disease caused by rapidly growing mycobacteria (RGM) in post-HSCT patients with pulmonary graft-versus-host disease, (2) RGM bloodstream infections in patients with acute lymphoblastic leukemia, and (3) slow-growing mycobacterial infections, mainly Mycobacterium avium complex, in patients with inborn errors of immunity. Diagnosis relies on microbiological culture and molecular techniques, while treatment requires prolonged multidrug regimens tailored to the causative species. In addition, structural lung damage, prolonged neutropenia, and chronic graft-versus-host disease are considered major risk factors for disease progression and dissemination. Early recognition and prompt initiation of appropriate antimicrobial therapy are essential to improve clinical outcomes. Furthermore, increasing awareness of NTM infections among hematologists may facilitate earlier diagnosis, appropriate screening, and multidisciplinary management strategies. This review summarizes the epidemiology, pathogenesis, clinical manifestations, diagnosis, and management of NTM infections in patients with hematological diseases.