Faculty Bibliography

Rationale Improved therapeutic options are needed for patients with treatment-refractory nontuberculous mycobacterial lung disease caused by Mycobacterium avium complex (MAC). Objectives To evaluate the efficacy and safety of daily amikacin liposome inhalation suspension (ALIS) added to standard guideline-based therapy (GBT) in patients with refractory MAC lung disease. Methods Adults with amikacin-susceptible MAC lung disease and MAC-positive sputum cultures despite ≥6 months of stable GBT were randomly assigned (2:1) to receive ALIS with GBT (ALIS+GBT) or GBT alone. Once-daily ALIS was supplied in single-use vials delivering 590 mg amikacin to the nebulizer. The primary endpoint was culture conversion, defined as 3 consecutive monthly MAC-negative sputum cultures by month 6. Measurements and Main Results Enrolled patients (ALIS+GBT, n=224; GBT-alone, n=112) were a mean 64.7 years old and 69.3% female. Most had underlying bronchiectasis (62.5%), chronic obstructive pulmonary disease (14.3%), or both (11.9%). Culture conversion was achieved by 65 of 224 patients (29.0%) with ALIS+GBT and 10 of 112 (8.9%) with GBT alone (OR, 4.22; 95% CI [2.08, 8.57]; P<0.001). Patients in the ALIS+GBT arm vs GBT alone were more likely to achieve conversion (hazard ratio, 3.90; 95% CI, [2.00, 7.60]). Respiratory adverse events (primarily dysphonia, cough, and dyspnea) were reported in 87.4% of patients receiving ALIS+GBT and 50.0% receiving GBT alone; serious treatment-emergent adverse events occurred in 20.2% and 17.9% of patients, respectively. Conclusions Addition of ALIS to GBT for treatment-refractory MAC lung disease achieved significantly greater culture conversion by month 6 than GBT alone, with comparable rates of serious adverse events. Clinical trial registration available at www.clinicaltrials.gov, ID NCT02344004.

Background: Aspiration is associated with non-tuberculous mycobacterial (NTM) pulmonary disease and airway dysbiosis is associated with increased inflammation. We examined whether NTM disease was associated with a distinct airway microbiota and immune profile.Methods: 297 oral wash and induced sputum samples were collected from 106 participants with respiratory symptoms and imaging abnormalities compatible with NTM. Lower airway samples were obtained in 20 participants undergoing bronchoscopy. 16S rRNA gene and a nested mycobacteriome sequencing approaches characterised microbiota composition. Inflammatory profiles of lower airway samples were also examined.Results: The prevalence of NTM+ cultures was 58%. Few changes were noted in microbiota characteristic or composition in oral wash and sputum samples among groups. Among NTM+ samples, 27% of the lower airway samples were enriched with Mycobacterium A mycobacteriome approach identified Mycobacterium in a greater percentage of samples, including some non-pathogenic strains. In NTM+ lower airway samples, taxa identified as oral commensals were associated with increased inflammatory biomarkers.Conclusions: The 16S rRNA gene sequencing approach is not sensitive in identifying NTM among airway samples which are culture positive. However, associations between lower airway inflammation and microbiota signatures suggest a potential role for these microbes in the inflammatory process in NTM disease.

PURPOSE OF REVIEW/OBJECTIVE:To highlight recent original research and specialty society guidelines regarding the diagnosis and treatment of nontuberculous mycobacterial (NTM) pulmonary disease. RECENT FINDINGS/RESULTS:The prevalence of NTM pulmonary disease has risen in recent years. The prevalence of individual NTM species varies geographically, although Mycobacterium avium complex (MAC) and Mycobacterium abscessus complex (MABC) remain among the most commonly encountered in many regions. Diagnosis and treatment of NTM pulmonary disease can be complex but guideline-based recommendations have been published. However, adherence to guideline recommendations is poor. Drug susceptibility testing plays a role with important caveats for treatment. Alternative therapies are being explored with older antimycobacterial drugs like clofazimine, which has demonstrated efficacy and tolerability for treatment-refractory NTM infections, and a novel formulation of amikacin for inhalation which may be better tolerated than parenteral administration. Several studies have shown that patients will have recurrences as high as 48%, and that these are not solely relapses but many cases are reinfections with a new organism. United States and European research registries of patients with non-cystic fibrosis bronchiectasis are expected to provide needed data on clinical characteristics of patients at risk for NTM pulmonary disease. SUMMARY/CONCLUSIONS:The evidence base for optimal management of NTM pulmonary disease is expanding but notable gaps in the literature remain.

Antibiotic therapy against non-tuberculous mycobacteria (NTM) is prolonged and can be associated with toxicity. We sought to evaluate whether chest physical therapy (PT) was associated with clinical improvement in patients with NTM not receiving anti-mycobacterial pharmacotherapy. A retrospective review of 77 subjects that were followed from June 2006 to September 2014 was performed. Baseline time point was defined as the first positive sputum culture for NTM; symptoms, pulmonary function, and radiology reports were studied. Subjects were followed for up to 24 months and results analyzed at specified time points. Half of the subjects received chest PT at baseline. Cough improved at 12 (p = 0.001) and 24 months (p = 0.003) in the overall cohort when compared with baseline, despite lack of NTM antibiotic treatment. Cough decreased at 6 (p = 0.01), 9 (p = 0.02), 12 (p = 0.02) and 24 months (p = 0.002) in subjects that received chest PT. Sputum production also improved at 24 months in the overall cohort (p = 0.01). There was an increase in the percent change of total lung capacity in subjects that received chest PT (p = 0.005). Select patients with NTM may have clinical improvement with chest PT, without being subjected to prolonged antibiotic therapy. Future studies are warranted to prospectively evaluate outcomes in the setting of non-pharmacologic treatment and aid with the decision of antibiotic initiation.