Title : Risk factors for mycobacterium avium complex infections in patients with chronic obstructive pulmonary disease
Abstract:
Purpose: With the increase incidences in non-tuberculous mycobacterial pulmonary disease(NTM-PD),comorbid lung disease and especially structural lung disease, such as chronic obstructive pulmonary disease(COPD),has been reported to influence its clinical features. However, the impact of COPD)on NTM-PD morbidity nad mortality ,and also impact of COPD phenotypes (airway predominance or emphysema predominance ) to the clinical features is not clear. The prevalence of Mycobacterium Avium Complex Pulmonary Disease(MAC-PD) significantly increased in the last years. The aim of our study was to evaluate the impact of low attenuation volume and emphysema prevalence on Computed Tomography(CT) on risk of development and clinical characteristics of MAC-PD.
Methods: We retrospectively reviewed 503 patients with COPD at the university teaching hospital between January 2020 and December 2025.We investigated the development rates and mortality risk of MAC-PD in COPD patients depending on phenotype of disease. CT-detected emphysema was defined as low attenuation area (LAA< -950 HU).Emphysema severity was assessed according to the Goddard scoring system.
Results: 321 of 503 patients(63.8%)had emphysema predominant phenotype of COPD on CT, and 182 (36.2%) had airway predominant phenotype of the disease.MAC-PD has been diagnosed in 122(24.3%) COPD patients and commonly was associated with emphysema phenotype of COPD(101 cases of 122 total).There was no significant difference in mean age, and the proportion of patients with Mycobacterium Intracellulare ,systemic and inhaled corticosteroid treatment ,and MAC-PD associated CT findings between patients with-and without emphysema ,excluding cavities which were higher prevalence in emphysema group(OR 3.44[0.87-7.22];p<0.001). MAC-PD patients with emphysema had more male gender(90.01% vs 26.9%;p<0.001) and significantly patients were current smokers and had history of smoking more than >25 pack-years(91.08% vs 30.76%;p<0.001).The severity of COPD assessing by exacerbation rate requiring hospitalization per one year was higher in MAC-PD with emphysema (OR 2.58[0.88-5.34];p<0.002).The average Goddard score of patients with emphysema was 6.1+_2.84(OR 10.22[2.45-18.31];p<0.0001).And Goddard score more than >50% was with an increased risk of development of MAC-PD (OR 5.24[2.12-8.38];p<0.001).Sixty one patients died during follow –up ,57 (56.4%) in emphysema group and 4(19%) and mortality rate was significantly higher in MAC_PD emphysema group(p<0.001).Higher Goddard score (>50%(p<0.02),cavities (p=0.015),low BMI <18.5kg/m2(p=0.003),low FEV1(p=0.02),and low DLCO (p=0.024) were associated with an increased mortality rate in patients. In contrast, higher blood eosinophilia and asthma comorbidity were associated with lower MAC-PD incidence in COPD patients(P,0.001). Co existing autoimmune diseases also significantly decreased the MAC_PD incidences in COPD (p<0.001) despite immune-supression therapy in such patients. Our results have been shown that type Th2 inflammation in COPD patients might be protective for COPD patients from MAC-PD.
Conclusions: There were several risk factors which may be associated an increased risk for development of MAC-PD in COPD patients and most important of these was higher low attenuation area on CT which was associated with more severe MAC-PD disease course and frequent disease exacerbations and mortality rate. Mortality risk was associated with emphysema severity, cavities ,lower nutrition status of patients, and low lung functions.Th2 type of inflammation might be protective for COPD patients from MAC-PD and is associated with significantly lower mortality risk.
