Evaluation of bronchial mucosa involvement in sarcoidosis patients using ¹⁸F-FDG PET-CT]

To explore the value of ¹⁸F-FDG PET-CT in evaluating bronchial mucosa involvement in patients with saroidosis.A retrospective analysis was conducted among 6 sarcoidosis patients with and 14 patients without bronchial mucosa involvement to collect the data including the standard uptake value (SUVMax/Mean) of ¹⁸F-FDG, serum angiotensin converting enzyme (sACE), and proportion of lymphocytes and CD4⁺/CD8 ⁺ T lymphocyte ratio in bronchoalveolar lavage fluid (BALF).The lung focal SUV(Max/Mean) was higher in patients with bronchial mucosa involvement than those without (7.04 ± 5.83/5.00 ± 4.69 vs 5.68 ± 3.66/3.82 ± 2.39), but such differences were not statistically significant (P=0.565/0.495). The SUV(Max/Mean) of the hilum of the lung and the mediastina lymph nodes were significantly higher in patients with bronchial mucosa involvement (13.28 ± 5.57/10.48 ± 4.43 vs 6.20 ± 1.77/4.52 ± 1.43, P=0.0003/0.0002; 13.84 ± 4.35/9.69 ± 2.74 vs 7.16 ± 2.52/5.28 ± 1.77, P=0.0004/0.0004). The level of sACE and CD4⁺/CD8 ⁺ T lymphocyte ratio in BALF were also significantly higher in patients with bronchial mucosa involvement (60.58 ± 16.3 vs 49.16 ± 13.3 IU/L, P=0.045; 7.30 ± 5.0 vs 2.90 ± 3.1, P=0.026). The proportion of lymphocytes in BALF was comparable between the patients with and without bronchial mucosa involvement (44.10 ± 10.3% vs 35.30 ± 12.5%, P=0.148).For patients with saroidosis, ¹⁸F-FDG PET-CT is useful in evaluating bronchial mucosa involvement, which is one of the key features of active sarcoidosis.