Relationship between CT activity score with lung function and the serum angiotensin converting enzyme in pulmonary sarcoidosis on chest HRCT

Abstract

To address the reliability of CT activity score (CTAS) and investigate the relationships between CTAS, lung function changes after treatment and the serum angiotensin-converting enzyme (SACE) levels.Fifty-seven sarcoidosis patients underwent chest high-resolution CT (HRCT) and spirometry, as well as SACE examination, were retrospectively analyzed. Follow-up spirometry in each patient was obtained about 6 months after the initial spirometry. The correlations between CTAS and pulmonary function changes were evaluated by Spearman correlation analysis. According to SACE status, patients were divided into normal and high level 2 subgroups. Comparisons of pulmonary function parameters, HRCT abnormalities extent scores between SACE normal and high 2 subgroups were performed with the Mann-Whitney U test or Independent samples t test.CTAS demonstrated significant correlations with lung function changes (Δ%VC: ρ= 0.543, P < .001; ΔFEV1.0/FVC:ρ = 0.417, P = .001; Δ%TLC: ρ = 0.309, P = .019). In addition, worse initial lung function, larger changes of lung function, and higher extent scores of HRCT were observed in SACE high-level subgroup.The findings of this study suggest that CTAS of initial HRCT is a promising index for disease activity in pulmonary sarcoidosis to some degree. Prospective studies with large cohort designed to address further verification are warranted before wide clinical practice.

Figure 1

A, HRCT obtained at the level of right lower bronchus displayed bilateral diffuse ground-glass opacities in a 41-year-old male patient. Note the right hilar lymphadenopathy. The SACE level was 60.1 U/mL. B, HRCT showed micronodules with a perivascular distribution and thickening of bronchovascular bundles accompanied with right pleural effusion in a 43-year female patient. The SACE value was 68.1 U/mL. C, HRCT demonstrated consolidation in subpleural region, multiple micronodules clustered interlobar fissures and centrilobular interstitium of right lower lobe in a 50-year-old female patient, enlarged right hilar lymph nodes were also seen, the SACE level was 28.3 U/mL. D, HRCT depicted right bronchovascular bundles distortion in a 48-year male patient, a usual finding of pulmonary fibrosis. Note the bilateral irregular thickening of the pleura (pseudoplaque) and multiple miliary nodules. The SACE value was 33.7 U/mL. HRCT = high-resolution CT, SACE = serum angiotensin converting enzyme.