Forced expiratory volume in 1 s (FEV1), force vital capacity (FVC), FEV1/ FVC, total lung capacity, DLCO, and DLCOc (i.e., hemoglobinâ€corrected DLCO) were significantly lower, while residual volume and sputum ILâ€6 levels were significantly higher in the patient group than in the control group. PFT parameters were more compromised in the patient subgroup with a history of ACS and older than 12 years compared with the subgroup without a history of ACS and the subgroup under 12 years of age. PFTs revealed significant negative correlations with age, number of ACS events, and sputum ILâ€6 levels
Pulmonary function was observed to worsen with disease progression, and it worsened with older age and repeated occurrence of ACS. Induced sputum ILâ€6 levels reflected the degree of lung inflammation in affected patients and were associated with more impairment in various PFT parameters.