Clinical significance of Autotaxin in primary biliary cholangitis and primary Sjogren′s syndrome / 中华风湿病学杂志

ABSTRACT

Objective:Primary biliary cholangitis (PBC) and Primary Sj?gren′s syndrome (pSS) are autoimmune epithelial inflammatory diseases that share many common clinical symptoms. The aim of this study was to investigate the differences and diagnostic value of Autotaxin (ATX) in PBC and SS.Methods:The clinical data of 237 cases diagnosed with PBC, PBC secondary to SS, pSS and healthy individuals(HC) between September 2020 and September 2021 were retrospectively analyzed. The levels of ATX in each group were measured by enzyme-linked immunosorbent assay (ELISA), and the corresponding sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under the curve ( AUC), etc were analyzed. Normally distributed data were expressed as mean ±SD and non-normally distributed as median (IQR). The differences and correlations between ATX and the biochemical tests in each group were assessed by applying the Mann-Whitney U test, Spearman correlation analysis, etc. P<0.05 was considered statistically significant difference. Results:The results showed that ATX was positive in 33.9%, 33.3% and 53.3% for PBC, PBC secondary SS, and pSS, respectively, with the specificities of 93.1%, 100% and 93.2%, respectively. The highest accuracy was achieved in pSS and the sensitivity and specificity were 86.5% and 93.2%, which were higher than those in PBC group(56.8%, 93.1%), respectively. Compared with HC [32.6(21.8, 60.5)ng/ml], ATX levels in PBC[59.3(48.6, 86.3)ng/ml, U=1 750.50, P<0.001], PBC-SS [73.6 (53.3,102.4)ng/ml; U=199.00, P<0.001], and pSS [152.6 (97.4,192.1)ng/ml, U=264.00, P<0.001] were elevated with significant difference ( P<0.05). ATX levels showed a decreasing trend from the pSS group to the HC group. ATX in PBC group[AUC(95% CI)= 0.73(0.651,0.812), P<0.001], PBC secondary SS group [AUC(95% CI)=0.82(0.730, 0.912), P<0.001], and pSS group [AUC(95% CI)=0.94(0.898, 0.984), P<0.001] had prediction accuracy. ATX was associated with total protein ( r=-0.31, P=0.041) level and glutaminase (r=-0.26, P=0.024) level. Conclusion:ATX has diagnostic value in both PBC and SS, and with higher sensitivity and specificity for the latter.