ABSTRACT
Objective To detect the serum levels of calpainin (S100A11) using nanomagicbeabs sorting-time resolved fluoroimmuno assay (NMBS-TRFIA) and evaluate its diagnostic value in pancreatic carcinoma.Methods 88 patients with pancreatic carcinoma,50 patients with acute pancreatitis,10 patients with pancreatic cyst and 20 healthy controls were selected as the study subjects.The human peripheral serum blood was sorted with S100A11 antibody coupled nanomagicbeabs,and the concentration of S100A11 was detected by TRFIA method.The area under the receiver operating characteristic (ROC) curve (AUC) was used to determine the cut-off level for diagnosis of pancreatic carcinoma,in order to evaluate the sensitivity and specificity for diagnosis of pancreatic carcinoma.Results S100A11 showed a linear relationship within the range of 6.08～ 500 ng/ml using NMBS-TRFIA method,intraassay CV≤6.35％,inter-assay CV≤7.12％,and the average recovery rate was 104.7％.The serum levels of S100A11 in patients with pancreatic carcinoma,patients with acute pancreatitis and patients with pancreatic cyst were 185.53 ± 161.19,106.06±113.83 and 68.99± 47.83 ng/ml respectively.Compared with the normal control group (37.98±25.14 ng/ml),the differences were statistically significant (t=-8.065,-3.375,-2.266,all P ＜0.01).The serum levels of S100A11 in patients with pancreatic carcinoma was significantly higher than those in patients with acute pancreatitis and patients with pancreatic cyst (all P＜0.05).According to the ROC curve,ROCAUC=0.985 (95％ CI:0.972 ～ 0.997),the best cut-off level for the diagnosis of pancreatic carcinoma was 89.5 ng/ml (sensitivity 81.8 ％,specificity 67.5 ％).Conclusion NMBS-TRFIA can enrich S100A11 in serum and improve the detection sensitivity of serum S100A11,and the method is simple and easy to be popularized.Serum S100A11 has a high sensitivity and specificity in the diagnosis of pancreatic carcinoma,and is a new serum marker for the diagnosis of early pancreatic carcinoma.