Real-life evaluation of clinical outcomes in patients undergoing treatment for non-tuberculous mycobacteria lung disease: A ten-year cohort study

Outcome recognition is a crucial step in the management of non-tuberculous mycobacteria lung disease (NTM-LD). In order to explore NTM-LD outcomes in a real-life setting, an observational, retrospective study enrolling consecutive adults who received treatment for NTM-LD in Milan, Italy, from 2007 to 2017 was conducted. Among 170 patients (68.2% females; median age: 68 years), NTM-LD was mainly due to M. avium complex (MAC) (71.2%), M. kansasii (9.4%) and M. xenopi (7.1%). Along a median follow-up of 31 months, adverse events occurred in 37.6% of the patients. Treatment outcomes of the entire study population included an unsuccessful outcome in 35.3% of the patients, including treatment halted in 13.5%, recurrence in 11.2%, re-infection in 5.3%, treatment failure in 4.1% and relapse in 1.2%. The main reason for treatment halted was drug intolerance. No differences were detected between patients with MAC-LD vs. those with other NTM-LD in terms of unsuccessful outcome in general (35.5% vs. 34.7%). A significantly higher prevalence of patients who underwent treatment halted was found in patients with NTM-LD other than MAC in comparison to patients with MAC-LD (22.4% vs. 9.9%, p = 0.030). One third of adults undergoing treatment for a NTM-LD experiences an unsuccessful outcome with adverse events and treatment discontinuation being major challenges in patients' management.