Serum total sialic acid in differential diagnostics of jaundice caused by malignant and nonmalignant diseases: a ROC curve analysis.

The purpose of this study was to evaluate the usefulness of serum total sialic acid (SA) for discrimination of malignant and nonmalignant jaundice. Serum SA concentration and its ratio with total protein (SA/TP) were determined in 55 patients with jaundice: 25 malignant and 30 nonmalignant. SA was estimated by enzymatic method. Serum total SA and the ratio SA/TP were significantly higher in malignant than in nonmalignant jaundice. Diagnostic sensitivity of SA and the ratio of SA/TP in both types of jaundice reached the value of 95.8%. The specificity, positive and negative predictive values, and efficiency of SA and SA/TP were higher in malignant than in nonmalignant jaundice. Areas under ROC curves for SA and the ratio of SA/TP in malignant jaundice were higher than in nonmalignant, but there were not statistically significant differences. SA levels and the ratio of SA/TP do not have the ability to discriminate between these types of jaundice.