Value of serological marker detection in hierarchical management of Crohn′s disease

Abstract

Objective To explore the values of serological markers in the phenotype diagnosis of Crohn′s disease (CD). Methods From January 2015 to December 2016, 100 patients diagnosed as CD were enrolled. The levels of human anti-Saccharomyces cerevisiae antibody (ASCA) IgG, ASCA IgA, anti-mannobioside carbohydrate antibody (AMCA), anti-chitobioside carbohydrate antibody (ACCA), antibody against outer membrane porin C of Escherichia coli (anti-OmpC), antibody against pseudomonas fluorescens (anti-I2), flagella protein antibody, perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) and antibodies to proteinase-3 (anti-PR3) were detected by indirect enzyme-linked immunosorbent assay (ELISA). Binary Logistic regression analysis was used to analyze the correlation between the serological markers and the phenotype of CD. The diagnosis values were evaluated by receiver operating characteristic (ROC) curve. Results The level of anti-I2 was significantly correlated with the narrow type of patients with CD (odd ratios (OR)=34.304, P=0.011); ACCA and flagella protein antibody were significantly correlated with the penetrating type of patients with CD (OR=1.024, P=0.027; OR=2.702, P=0.021). ASCA IgA and AMCA were significantly correlated with the lesion involved gastric, duodenum and small intestine in CD patients (OR=1.146, P=0.044; OR=1.035, P=0.013). In the diagnosis of narrow type CD, the diagnostic accuracy of anti-I2 was the highest (area under curve (AUC)=0.631, P=0.043), and according to this result, its best cutoff value was 0.650, and then the sensitivity increased to 28.6% (8/28). In the diagnosis of penetrating type CD, the diagnostic accuracy of flagella protein antibody was the highest (AUC=0.725, P<0.01). Anti-OmpC (AUC=0.677, P=0.006) and ACCA (AUC=0.644, P=0.025) also had higher diagnostic accuracy. According to these results, the best cutoff values of flagella protein antibody, anti-OmpC and ACCA were 0.395, 0.225 and 59.500, respectively, and then their sensitivity improved after correcting the cutoff values. The AUC of any one item positive in the combination of flagella protein antibody, anti-OmpC and ACCA in the diagnosis of penetrating type CD was 0.761 (P<0.01), which was significantly higher than the diagnostic accuracy of single antibody detection. In the diagnosis of the lesions involved gastric, duodenum and small intestine, the diagnostic accuracy of AMCA was the highest, and its AUC was 0.817 (P<0.01). ASCA IgA (AUC=0.772, P=0.001) and ACCA (AUC=0.752, P=0.001) also had higher diagnostic accuracy. The AUC of any one item positive of ASCA IgA and AMCA in the diagnosis of CD lesions involved gastric, duodenum and small intestine was 0.905 (P<0.01), which was significantly higher than the diagnostic accuracy of single antibody detection. The best cutoff values of ASCA IgA, AMCA and ACCA were 21.500, 55.000 and 29.500, respectively. And their sensitivity improved after correcting the cutoff values. The sensitivity of any one item positive in the three items also improved. Conclusion The detection of serological markers has great clinical values in the hierarchical management of phenotypes in Chinese CD population. Key words: Crohn disease; Enzyme-linked immunosorbent assay; Serological markers; CD phenotype