Progression and mortality of Mycobacterium abscessus complex pulmonary disease

Despite the rising importance of Mycobacterium abscessus pulmonary disease, robust analyses of its prognosis and predictors remain limited. We aimed to determine the progression rate, treatment outcomes, mortality rate, and prognostic factors in patients with M. abscessus pulmonary disease.

Adult patients diagnosed with M. abscessus pulmonary disease at a referral center in South Korea between January 1, 2011 and December 31, 2023 were included. Clinical characteristics, laboratory findings, and radiographic features were collected. Progression, treatment outcomes, all-cause mortality, and their predictors were analyzed. We evaluated the prognostic value of the BACES score in predicting clinical outcomes.

421 patients diagnosed with M. abscessus pulmonary disease (M. abscessus subspecies abscessus [n = 248] and M. abscessus subspecies massiliense [n = 173]) were included. Over a median follow-up of 4.4 years, 203 (48.2%) patients experienced progression. Among the 135 patients treated with guideline-based therapy, 72 (53.3%) achieved microbiological cure. The 5- and 10-year overall survival rates were 88.8% and 70.8%, respectively. The BACES scores were associated with progression and mortality in treated patients. Clarithromycin resistance, including inducible resistance, was a major predictor of failure to achieve microbiological cure (adjusted odds ratio, 0.09; 95% confidence interval (CI), 0.036-0.205) and of increased mortality in treated patients (adjusted hazard ratio, 3.089; 95% CI, 1.129-9.997).

Approximately half of patients with M. abscessus pulmonary disease experienced progression, and over half of the treated patients achieved microbiological cure. The BACES score and clarithromycin resistance could serve as reliable predictors of progression and mortality.