Szérum és endoszkópos markerek diagnosztikus és prognosztikus szerepe gyulladásos bélbetegségekben
The most important goals of the recent therapies of inflammatory bowel disease are to induce and maintain clinical remission and mucosal healing. However, symptoms are frequently inconsistent with endoscopic findings. Serum infliximab and antibody-to-infliximab levels are objective parameters that may have a great role in the therapeutic decision making during maintenance biological therapy. The aims of this thesis were to evaluate the correlation between clinical and endoscopic disease activities of ulcerative colitis defined by activity scores in 100 consecutive patients, to assess the correlation between serum infliximab and antibody-to-infliximab levels, the response to infliximab therapy, and to determine the accuracy of serum drug concentration measurement in the prediction of the long-term clinical response in 48 patients suffer from inflammatory bowel disease. Significant correlation was shown between the clinical activity and mucosal healing (p=0.0012 and p<0.001). In this part of the thesis, we evaluated serum infliximab levels, and found that single measurement of antibody-to-infliximab titers was insufficient for predicting therapeutic response due to transient expression of antibody-to-infliximab, however, using the three points' measurements, significant difference was detected between the adequate and inadequate responder group (5.0% vs. 35.7%; p=0.016). Sensitivity and specificity for predicting the therapeutic response were 85.0% and 71.4% based on the cut-off value of trough level 2.0 mg/ml. Our results showed good correlation between the clinical, endoscopic, and histological activities of UC focusing on the importance of evaluating the endoscopic activity of patients. Simultaneous measurement of serum infliximab level prior to administration of regular infliximab infusion and antibody-to-infliximab titers significantly increase the diagnostic accuracy for the therapeutic decision making in patients with indeterminate response to the therapy.