Background

Treatment of nontuberculous mycobacterial (NTM) infections is often associated with toxicity which may result in treatment adjustments potentially affecting outcome.

Objectives

We describe treatment deviations, the reasons behind and the outcome of patients treated for NTM pulmonary disease (PD) at a tertiary center.

Methods

Retrospective, observational cohort of adults with NTM-PD, according to ATS/IDSA diagnostic criteria, who presented to the Pulmonology Department of UZ Leuven from Jan 2016 through Dec 2021. Consensus treatment outcome definitions by NTMnet were applied. Descriptive statistics of data collected through medical chart review; data censored at June 1, 2022.

Results

41/63 patients with NTM-PD (60% female, median age 63 years; 54% with nodular bronchiectactic, 7% fibrocavitary and 34% mixed disease) were started on antibiotic therapy. Most common isolates were MAC (n=23) and M. abscessus complex (n=9).

Adverse events (AE) ? most common ototoxicity, gastro-intestinal intolerance - required treatment adjustments in 23/41 (56%): 11, 4 and 8 patients before 3, 6 and 12 months respectively. AE resulted in temporary treatment interruptions in 11/41 (27%) and early termination in 2 patients. Treatment was completed in 19/41 (46%), and is ongoing for 2. Less than 1/4 (10/41) achieved clinical and microbiological cure, 29% microbiological cure, 15% failed therapy and 7% were lost to follow-up.

Conculsion

Treating NTM infections is challenging. Less than 50% of patients in our study completed initial guideline based therapy. AE often led to treatment changes, potentially jeopardizing outcomes. New regimens are urgently needed to improve tolerability and efficacy.