Serum immunoinflammation-related protein complexes discriminate between inflammatory bowel disease and colorectal cancer

Purpose Inflammatory bowel disease (IBD) is an important risk factor for colon cancer. Novel serum immunoinflammation-related protein complexes (IIRPCs) have shown associations with early cancer detection. Herein, we investigated the potential of serum IIRPCs for discriminating between IBD and colorectal cancer (CRC) patients. Methods Serum protein complexes of 65 healthy controls, 57 CRC, 69 (ulcerative colitis) UC, and 67 (Crohn's disease) CD patients were isolated by native-PAGE. The gray values of serum IIRPCs bands in the gel were quantified using Quantity One software. The receiver-operating characteristic (ROC) curves were constructed to assess the discriminating ability by calculating the area under the ROC curve. Results The serum IIRPCs levels in IBD and CRC patients were significantly elevated compared to healthy controls. ROC analysis indicated certain diagnostic ability of serum IIRPCs in differentiating IBD from CRC. Specifically, a3 complex discriminated UC from CRC, with an AUC value of 0.722, sensitivity of 69.4% and specificity of 63.8%. Similarly, b4 complex discriminated UC from CRC, with an AUC value of 0.709, sensitivity of 70.4%, and specificity of 60.0%. In addition, the a3 complex also discriminated CD from CRC, with an AUC value of 0.785, sensitivity of 73.1%, and specificity of 74.1%, while the b4 complex showed a tendency to discriminate CD from CRC, with an AUC value of 0.663, sensitivity of 67.9% and specificity of 50.0%. Thus, an equation based on multiple IIRPCs was built to further improve the discriminating power. Conclusions Serum IIRPCs can be used to discriminate IBD from CRC and may also be associated with early screening of colitis-associated cancer.