Abstract Background The clinical course of pulmonary Mycobacterium intracellulare disease varies considerably among patients, and factors contributing to disease progression remain unclear. We hypothesized that specific genetic clusters of M. intracellulare, as identified by variable-number tandem-repeat (VNTR) analysis, may be related to disease progression and health-related quality of life (QOL). Methods We analyzed 25 patients diagnosed with pulmonary M. intracellulare disease at 10 institutions between January 2015 and April 2017. Disease status was classified as either stable or slowly progressive based on serial CT findings. VNTR genotyping was performed, and associations among cluster patterns, disease progression, and SF-36v2 QOL scores were evaluated. Results Of the 25 patients, 17 had stable disease and 8 had slowly progressive disease. The median age was 71 years, and the mean BMI was 16.3 kg/m². The physical component summary of the SF-36v2 was significantly lower in the progressive group, although mental health scores did not differ between groups. VNTR analysis revealed possible unique cluster formations that appeared to be associated with the progressive type. Conclusion This study explored the existence of unique VNTR-defined genetic clusters related to the progression of pulmonary M. intracellulare disease. The findings suggest that certain clusters may be associated with disease progression, highlighting the need for larger-scale studies to clarify these genetic and clinical relationships. This abstract is funded by: None
Fujita et al. (Fri,) studied this question.