AUTHOR=Wang Yukai , Xie Xuezhen , Zheng Shaoyu , Du Guangzhou , Chen Shaoqi , Zhang Weijin , Zhuang Jinghua , Lin Jianqun , Hu Shijian , Zheng Kedi , Mikish Angelina , Xu Zhuangyong , Zhang Guohong , Gargani Luna , Bruni Cosimo , Hoffmann-Vold Anna-Maria , Matucci-Cerinic Marco , Furst Daniel E. 

TITLE=Serum B-cell activating factor and lung ultrasound B-lines in connective tissue disease related interstitial lung disease

JOURNAL=Frontiers in Medicine

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.1066111

DOI=10.3389/fmed.2022.1066111

ISSN=2296-858X

ABSTRACT=<sec><title>Objective</title><p>To investigate the role of serum B-cell activating factor (BAFF) and lung ultrasound (LUS) B-lines in connective tissue disease related interstitial lung disease (CTD-ILD), and their association with different ILD patterns on high resolution computed tomography (HRCT) of chest.</p></sec><sec><title>Methods</title><p>We measured the levels of BAFF and KL-6 by ELISA in the sera of 63 CTD-ILD patients [26 with fibrotic ILD (F-ILD), 37 with non-fibrotic ILD (NF-ILD)], 30 CTD patients without ILD, and 26 healthy controls. All patients underwent chest HRCT and LUS examination.</p></sec><sec><title>Results</title><p>Serum BAFF levels were significantly higher in CTD patients compared to healthy subjects (617.6 ± 288.1 pg/ml vs. 269.0 ± 60.4 pg/ml, <italic>p</italic> &lt; 0.01). BAFF concentrations were significantly different between ILD group and non-ILD group (698.3 ± 627.4 pg/ml vs. 448.3 ± 188.6 pg/ml, <italic>p</italic> &lt; 0.01). In patients with ILD, BAFF concentrations were significantly correlated with B-lines number (<italic>r</italic> = 0.37, 95% CI 0.13–0.56, <italic>p</italic> &lt; 0.01), KL-6 level (<italic>r</italic> = 0.26, 95% CI 0.01–0.48, <italic>p</italic> &lt; 0.05), and Warrick score (<italic>r</italic> = 0.33, 95% CI 0.09–0.53, <italic>p</italic> &lt; 0.01), although all correlations were only low to moderate. B-lines number correlated with Warrick score (<italic>r</italic> = 0.65, 95% CI 0.48–0.78, <italic>p</italic> &lt; 0.01), and KL-6 levels (<italic>r</italic> = 0.43, 95% CI 0.21–0.61, <italic>p</italic> &lt; 0.01). Patients with F-ILD had higher serum BAFF concentrations (957.5 ± 811.0 pg/ml vs. 516.1 ± 357.5 pg/ml, <italic>p</italic> &lt; 0.05), KL-6 levels (750.7 ± 759.0 U/ml vs. 432.5 ± 277.5 U/ml, <italic>p</italic> &lt; 0.05), B-lines numbers (174.1 ± 82 vs. 52.3 ± 57.5, <italic>p</italic> &lt; 0.01), and Warrick score (19.9 ± 4.6 vs. 13.6 ± 3.4, <italic>p</italic> &lt; 0.01) vs. NF-ILD patients. The best cut-off values to separate F-ILD from NF-ILD using ROC curves were 408 pg/ml for BAFF (AUC = 0.73, <italic>p</italic> &lt; 0.01), 367 U/ml for KL-6 (AUC = 0.72, <italic>p</italic> &lt; 0.05), 122 for B-lines number (AUC = 0.89, <italic>p</italic> &lt; 0.01), and 14 for Warrick score (AUC = 0.87, <italic>p</italic> &lt; 0.01) respectively.</p></sec><sec><title>Conclusion</title><p>Serum BAFF levels and LUS B-lines number could be useful supportive biomarkers for detecting and evaluating the severity and/or subsets of CTD-ILD. If corroborated, combining imaging, serological, and sonographic biomarkers might be beneficial and comprehensive in management of CTD-ILD.</p></sec>