Lung function decline in non-tuberculous mycobacterial pulmonary disease according to disease severity

B A C K G R O U N D : The severity of non-tuberculous my-cobacterial pulmonary disease (NTM-PD) can be classified based on an assessment of the patient's body mass index, age, presence of cavity, erythrocyte sediment rate and sex (BACES). In this study, changes in lung function according to disease severity were analysed.M E T H O D S : Patients with NTM-PD who underwent at least two lung function tests between 1 January 2011 and 31 December 2021, were classified according to their BACES score into mild (0-1), moderate (2-3) and severe (4-5) groups, and changes in lung function were assessed using BACES scores.R E S U LT S : A total of 354 patients were divided into three groups: mild (n = 108), moderate (n = 216) andsevere (n = 30). As disease severity increased, the decrease in forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO) was greater: respectively 26.4 mL/year, 31.3 mL/year and 35.7 mL/year in case of FEV1(P for trend = 0.002); 18.9 mL/year, 25.5 mL/year and 48.9 mL/year in case of FVC (P for trend = 0.002); and 0.7%/year, 1.3%/year and 2.5%/year for DLCO (P for trend = 0.023) in the mild, moderate and severe groups.C O N C L U S I O N : The decrease in lung function in NTM-PD was correlated with disease severity.