Analysis of clinical characteristics of different types of lung function impaiement in TDL patients

The clinical characteristics associated with pulmonary function decline in patients with Tuberculosis-destroyed lung (TDL) remain uncertain. We categorize them based on the pattern of pulmonary function impairment, distinguishing between restrictive spirometric pattern (RSP) and obstructive spirometric pattern (OSP). We aim to compare the severity of these patterns with the clinical characteristics of TDL patients and analyze their correlation.

We conducted a retrospective analysis on the clinical data of TDL patients who underwent consecutive pulmonary function tests (PFT) from November 2002 to February 2023. We used the lower limit formula for normal values based on the 2012 Global Lung Function Initiative. We compared the clinical characteristics of RSP patients with those of OSP patients. The characteristics of RSP patients were analyzed using the tertiles of forced vital capacity percentage predicted (FVC% pred) decline based on PFT measurements, and the characteristics of OSP patients were analyzed using the tertiles of forced expiratory volume in 1 s percentage predicted (FEV₁% pred) decline.

Among the RSP patients, those in the Tertile1 group (with lower FVC% pred) were more likely to have a higher of body mass index (BMI), spinal deformities, and C-reactive protein (CRP) compared to the other two groups (P for trend < 0.001, 0.027, and 0.013, respectively). Among OSP patients, those in the Tertile1 group (with lower FEV₁% pred) showed an increasing trend in cough symptoms and contralateral lung infection compared to the Tertile 2-3 group (P for trend 0.036 and 0.009, respectively).

For TDL patients, we observed that Patients with high BMI, a higher proportion of spinal scoliosis, and abnormal elevation of CRP levels were more likely to have reduced FVC. Patients with decreased FEV₁% pred have more frequent cough symptoms and a higher proportion of lung infections on the affected side.