Expression and significance of KL-6 mucin in the bile and serum in differential diagnosis of benign and malignant obstructive jaundice

Objective To investigate the clinical value of KL-6 mucin in differential diagnosis of benign and malignant obstructive jaundice. Methods A total of 41 patients with malignant tumors and 15 with benign lesions were recruited in the study. KL-6 mucin levels of bile and serum were measured using enzyme-linked immunosorbent assay （ELISA）. The serum alpha-fetoprotein （AFP）, carcinoembryonic anti-gen （CEA） and carbohydrate antigen （CA） 19-9 levels were also measured using radioimmunoassay （RIA）. All data were analyzed by Mann-Whitney U test and Receiver Operating Characteristics （ROC） curves. Results CEA, CA19-9, and KL-6 mucin in serum and KL-6 mucin in bile in patients with malig-nant tumors were significantly higher than those in patients with benign lesions （P 〈 0. 001 ）. There were no significant differences in serum AFP between the two groups. An receiver operating characteristic （ROC） curves analysis revealed that the detection of KL-6 mucin in bile was reasonably accurate in differentiating malignant obstructive jaundice from benign （area under curve [ AUC] 0. 954）. While the AUC of the ROC curves for serum AFP, CEA, CA19-9, KL-6 mucin and KL-6 in bile and 0.954 were 0.657, 0.753, 0. 894, 0. 846 and 0. 954 respectively. Using the ideal threshold as the cut-off point, the sensitivity and spe-cificity of KL-6 mucin for differential diagnosis of benign and malignant obstructive jaundice was 90. 24% and 93.33%. Conclusion As a tumor marker, KL-6 mucin in bile is valuable in differential diagnosis of benign and malignant obstructive jaundice. Key words: Jaundice, Obstructive;  Bile ;  KL-6 mucin;  Differential diagnosis