Phenotyping of chronic obstructive pulmonary disease using the modified Bhalla scoring system for high-resolution computed tomography.

Background: Identifying different phenotypes of chronic obstructive pulmonary disease (COPD) is important for both therapeutic options and clinical outcome of the disease.

Objective: To characterize the phenotypes of COPD according to high-resolution computed tomography (HRCT) findings; and to correlate HRCT scores obtained using the modified Bhalla scoring system with clinical and physiological indicators of systemic inflammation.

Methods: The present study included 80 consecutive patients with stable COPD. HRCT scans were evaluated by two independent radiologists according to the modified Bhalla scoring system.

Results: Fifty-four patients exhibited morphological changes on HRCT examination while 26 had no pathological findings. Patients with HRCT findings had lower spirometric measurements and higher levels of inflammation, and reported more exacerbations in the previous year compared with patients with no findings on HRCT. Patients with morphological changes were classified into one of three groups according to their HRCT phenotype(s): emphysema (E) only, E + bronchiectasis (B)⁄peribronchial thickening (PBT) or B⁄PBT only. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1⁄FVC ratio, C-reactive protein (CRP) levels and the number of exacerbations among the groups were significantly different. Pairwise comparisons between the E only and E+B⁄PBT groups showed significantly lower FVC, FEV1 and FEV1⁄FVC values, and higher CRP levels and number of exacerbations compared with the B⁄PBT group. No significant differences were found between the E+B⁄PBT and the B⁄PBT groups. An inverse correlation was found between the total HRCT score and FVC, FEV1 and FEV1⁄FVC; the correlation was positive with CRP level, erythrocyte sedimentation rate and number of exacerbations.

Conclusion: The present study exposed the intimate relationship between phenotype(s) characterized by HRCT and scoring for morphological abnormalities; and clinical and functional parameters and inflammatory markers. The inclusion of HRCT among routine examinations for COPD may provide significant benefits both in the management and prognosis of COPD patients.