Evaluation of serum sialic acid detection kit using enzymic method and investigate the clinical diagnosis value of sialic acid

Abstract

Objective To evaluate the performance of serum sialic acid detection kit using enzymic method and investigate the clinical diagnosis value of sialic acid. Methods one hundred and fifty healthy adults were enrolled in this case control study to establish serum SA reference interval.The analytical performance (accuracy, precision, linearity)of serum sialic acid detection kit using enzymic method was assessed.Two hundred and forty patients were classified into different malignant tumor groups according to their pathological types.Serum SA level of each tumor group was compared with that of normal control group.In tumor groups with statistical difference, benign disease groups were further collected.Receiver operating characteristic (ROC) curve and area under curve (AUC) were used to evaluate the diagnostic value of SA compared with other tumor markers.t test, one-way ANOVA,Mann-Whitney U test were used as statistical methods. Results The reference interval of SA was 479 to 715 mg/L.The detection result of 2 level controls was 584 and 1 482 mg/L respectively, which were both within the acceptable limits.The within-lot and between-lot variations of three level samples were both below 5%.There was a good linear correlation(Y=0.995X-0.177, R2=0.999) between theoretical value and actual detection result in range of 0-1 052 mg/L.The serum level of SA was(757±177), (514±86) and (597±60) mg/L in gastric cancer group, benign disease control group and normal control group respectively, which had statistically significant difference(F=55.2, P 0.05).The AUC of SA was 0.804,0.724,0.755 in gastric cancer group, colorectal cancer group and lung cancer group respectively, which was higher than that of CEA and CA72-4. In gastric cancer group, the sensitivity of SA was higher than that of CEA (59.5%,24.3%).The AUC of SA was 0.791,0.687,0.790 in gastric cancer, colorectal cancer and lung cancer patients with normal CEA serum level respectively. Conclusions Experimental results show that serum sialic acid detection kit using enzymic method has good performance in the precision and linearity.Sialic acid has some value in the diagnosis of gastric cancer and colorectal cancer and could be a good supplement of CEA in screening of cancer.（Chin J Lab Med,2014,37:189-193） Key words: N-acetylneuraminic acid; Clinical enzyme tests; Tumor markers, biological; Evaluation studies