To investigate the clinical significance of procalcitonin (PCT) for patients with obstruction and early infection of biliary tract.

From August 2015 to July 2016, a total of 63 patients with obstruction of biliary tract were treated surgically in Huaxi Hospital of Sichuan University. According to bile culture and symptoms after operation, 63 cases were divided into non-infection group (24 cases) and infection group (39 cases). The count of white blood cell (WBC), neutrophil ratio (NE%), PCT level of patients in the two groups were compared, respectively. The diagnostic value of PCT, WBC and NE% for infection of biliary tract were analyzed, including the area under ROC curve, sensitivity, specificity and Yoden index, while the changes of PCT, WBC and NE% of patients in infection group before and after operation were analyzed, respectively.

PCT, WBC and NE% of patients in infection group were significantly higher than those in non-infection group [(1.35 ± 0.15) ng/ml, (9.48 ± 1.17) × 10⁹/L, (79.24 ± 7.83) vs. (0.16 ± 0.04) ng/ml, (8.14 ± 0.87) × 10⁹/L, (67.93 ± 6.09)], with significant differences (t = 37.936, 4.841, 6.035; all P < 0.001). The area under ROC curve of PCT, WBC and NE% of patients in infection group were 0.904, 0.568 and 0.519, respectively. The sensitivity, specificity and Yoden index of PCT were significantly higher than those of WBC and NE%. The levels of PCT, WBC and NE% of patients in infection group 3 days after operation were significantly lower than those before operation [(2.63 ± 0.21) ng/ml, (10.27 ± 1.35) × 10⁹/L, (79.96 ± 7.23) vs. (0.86 ± 0.09) ng/ml, (8.23 ± 0.97) × 10⁹/L, (71.11 ± 6.36)], with significant differences (t = 39.049, 6.442, 4.933; all P < 0.001).

PCT has high diagnostic value for early bile duct infection of patients with obstruction, with significant sensitivity and specificity.