Mycobacterium Avium-Intracellulare Infection

The purpose of this study is to find out if the Mycobacterium bovis Bacillus Calmette Guerin (BCG) vaccine can be used safely to treat Mycobacterium avium complex (MAC) lung disease. Researchers will compare responses from patients with MAC lung disease after receiving an injection of BCG or placebo (a look-alike substance that contains no drug) Participants in the study: * Receive a BCG or placebo injection at UVA study center on Day 0 * Come to UVA study center on Day 60 * Come to UVA study center at the end of the study * Answer surveys and questionnaires about how you are doing * Have blood drawn 3 times, on injection day, day 60, and at end of study * Give the study team personal and demographic information * Discuss any new symptoms with the study team * Provide monthly sputum samples per usual care

The incidence and prevalence of nontuberculous mycobacteria (NTM) infections have gradually increased over the years worldwide (1-3). In China, Mycobacterium avium complex (MAC) was the most prevalent NTM specie (4), while challenged by long treatment duration, frequent drug-induced adverse events, lack of treatment alternatives, poor treatment outcome and high recurrence rate (5, 6). In order to maximize the efficacy of the few available drugs and prevent the development of drug resistance, ensuring adequate plasma drug concentrations are of importance. Despite the role of pathogen susceptibility, determined by minimum inhibitory concentration (MIC), is non-negligible, the evidences regarding its association with treatment outcome are limited, especially for rifamycin and ethambutol. The difficulties in explaining the clinical values of MIC might partially be attributed to the lack of in vivo drug exposure data, which cannot be accurately predicted by the dose administered because of between-patient pharmacokinetic variability (7). Therapeutic drug monitoring (TDM) is a strategy to guide and personalize treatment by measuring plasma drug concentrations and pathogen susceptibility, which might have the potential to improve treatment response to MAC lung disease. In this observational study, the hypothesis is that the drug exposure and/or MIC of antimycobacterial drugs are correlated to the treatment response of MAC lung disease, which is assessed from the perspective of treatment outcome, mycobacterial culture negative conversion, lung function, radiological presentation and self-reported quality of life. Consenting adult patients with culture-positive MAC lung disease will be recruited in study hospital. Respiratory samples (sputum and/or bronchoalveolar lavage fluid) will be collected regularly for mycobacterial culture on the basis of BACTEC MGIT 960 system and MIC will be determined using a commercial broth microdilution plate. Drug concentrations will be measured at 1 and/or 6 months after treatment initiation using liquid chromatography tandem mass spectrometry (LC-MS/MS). The final treatment outcome is recorded at the end of MAC treatment and defined according to an NTM-NET consensus statement (8).