New Registry Data on MAC Pulmonary Disease Outcomes

This episode, "New Registry Data on MAC Pulmonary Disease Outcomes," features Dr. Losier examining new registry data on real-world MAC epidemiology and outcomes.

Dr. Losier reviews a prospective, multi-center registry study designed to characterize real-world epidemiology, clinical phenotype, and outcomes of NTM pulmonary disease. Investigators enrolled patients meeting the 2020 ATS/ERS/IDSA diagnostic criteria and prospectively collected demographic data, underlying lung disease history, CT chest imaging phenotypes, infecting NTM species, and treatment regimens. They tracked culture conversion and mortality, then used descriptive analyses and multivariable regression to identify predictors of treatment outcomes.

Dr. Losier explains that MAC was by far the most predominant cause of NTM pulmonary disease, a finding consistent across geographic regions and patient subgroups. The typical patient was an older woman, generally between 65 and 70 years old. CT phenotyping showed bronchiectasis was a common underlying condition, with nodular bronchiectatic disease the most frequent radiographic pattern. Fibrocavitary disease, though less common, was consistently linked to worse outcomes. Culture conversion with current guideline-based therapy succeeded in only 40% to 60% of patients across participating centers. Patients who remained culture positive after six months represented a substantial refractory population with higher morbidity and mortality; five-year all-cause mortality reached 30% to 42% among symptomatically treated patients.

Dr. Losier's key takeaway is that NTM pulmonary disease should not be treated as an incidental microbiologic finding. The data reveal substantial disease burden across regions, with particularly concerning outcomes in patients with advanced radiographic disease. She argues clinicians should comprehensively characterize each patient at diagnosis, accounting for infecting species, CT phenotype, symptom burden, comorbidities, and underlying lung disease to gauge risk of progression. Rather than treating every positive culture the same way, she recommends identifying higher-risk patients early so clinicians can intervene before disease becomes fibrocavitary or refractory, given the clear links to morbidity and mortality.

Our next episode, "ENCORE Trial Explores Earlier Amikacin Therapy for MAC," examines whether starting inhaled amikacin liposome therapy earlier can change the course of newly diagnosed disease.