Evaluation of the effectiveness of biological agents in the treatment of inflammatory bowel diseases

Objective: The aim of the study; The aim of this study is to evaluate the effectiveness of biological treatments in achieving remission in inflammatory bowel diseases, their response differences, their superiority over each other, and the factors that may affect unresponsiveness. Materials and Methods: In our study, the files of 1130 patients who were followed up with the diagnosis of UC or CD in the inflammatory bowel diseases outpatient clinic of Gaziantep University Faculty of Medicine between 2012 and 2022 were retrospectively reviewed. 105 patients who received at least one biological agent and met the inclusion criteria were included in the study. Demographic characteristics of the patients, types of involvement, disease severity, extraintestinal complications, fistula status, immunomodulatory drug use were examined. The clinical and laboratory responses at 3,12,24,36,48 and 60th months after treatment were recorded, and the responses of biological treatments were compared with each other. Results: 42.8% of the patients are followed in remission with the first Anti-TNF and the mean follow-up period is 38.4 months. Primary and secondary clinical response rates were 87.8% vs 73.2% in Adalimumab, 90.3% and 73.1% in Infliximab, 83.3% and 58.3% in certolizumab, respectively. The highest primary response rate in the use of multiple biological agents was observed in Adalimumab (92.3%), followed by Infliximab (78.3%), Vedolizumab (75%) and Sertolizumab (57.14%), respectively. Infliximab had the highest rate of fistula closure and clinical response in anti-TNF naive fistulizing Crohn's patients, statistically significantly higher than Adalimumab and Sertolizumab (p:0.0431). Although the rate of patients who received azathioprine combination therapy among the patients who responded to the first Anti-TNF at the 52nd week was found to be higher than those who received anti-TNF monotherapy, this rate was not statistically significant (p: 0.763, p: 0.786). Unresponsiveness to the first Anti-TNF was found to be statistically higher in females (p:0.041). A significant correlation was found between first Anti-TNF 52nd week unresponsiveness and increased baseline CRP, PLT and N/L ratio (p:0.044, p:0.013, p:0.036, respectively). A statistically significant correlation was found between the use of multiple biological agents and the initial CRP elevation (p:0.025). Conclusion: Biological agents are effective agents in providing permanent remission and histological recovery of the diseases in moderate-severe UC and CD patients. Knowing the demographic data of patients, presence of fistula and laboratory parameters can be effective in choosing the right Anti-TNF and predicting unresponsiveness. Keywords: Inflammatory bowel diseases, TNF-alpha inhibitors, biologic agent