Aim: To investigate the correlation between rs2910164, rs11 614913, rs113054794, and rs188519172 polymorphisms and response to anti-TNF treatment in patients with Crohn's disease (CD).

Methods: One hundred seven patients with CD based on standard clinical, endoscopic, radiological, and pathological criteria were included in the study. They all received infliximab or adalimumab intravenously or subcutaneously at standard induction doses as per international guidelines. Clinical and biochemical response was assessed using the Harvey-Bradshaw index and CRP levels respectively. Endoscopic response was evaluated by ileocolonoscopy at week 12-20 of therapy. The changes in endoscopic appearance compared to baseline were classified into four categories, and patients were classified as responders and non-responders. Whole peripheral blood was extracted and genotyping was performed by PCR.

Results: One hundred and seven patients were included in the study. Seventy two (67.3%) patients were classified as complete responders, 22 (20.5%) as partial while 13 (12.1%) were primary non-responders. No correlation was detected between response to anti-TNF agents and patients' characteristics such as gender, age and disease duration while clinical and biochemical indexes used were associated with endoscopic response. Concerning prevalence of rs2910164, rs11614913, and rs188519172 polymorphisms of miR-146, miR-196a and miR-224 respectively no statistically important difference was found between complete, partial, and non-responders to anti-TNF treatment. Actually CC genotype of rs2910164 was not detected in any patient. Regarding rs113054794 of miR-221, normal CC genotype was the only one detected in all studied patients, suggesting this polymorphism is highly rare in the studied population.

Conclusion: No correlation is detected between studied polymorphisms and patients' response to anti-TNF treatment. Polymorphism rs113054794 is not detected in our population.