From January 2020 to January 2025, Crohn's disease (CD) patients and gender- and age-matched normal controls were collected from the Department of Gastroenterology, the Second Affiliated Hospital of Wenzhou Medical University. The aim of this research is to explore the associations of microribonucleic acids (miRNAs) gene polymorphisms with the risk and clinicopathological characteristics of CD, and to analyze the effects of miRNAs gene variantions on the clinical response of ustekinumab (UST) treatment in CD patients at week 8.

From January 2020 to January 2025, a total of 312 CD patients and 527 gender- and age-matched normal controls were collected from the Department of Gastroenterology, the Second Affiliated Hospital of Wenzhou Medical University.The genotypes of miRNAs were determined by multiplex polymerase chain reaction-ligase detection reaction technique. Unconditional logistic regression was employed to analyze the distribution of miRNAs gene polymorphisms between CD group and normal control group, as well as their influences on the clinicopathological characteristics of CD patients. Unconditional logistic regression model was used to explore the effect of miRNAs gene variation on the clinical response of CD patients in the treatment of UST at week 8.

Inclusion Criteria:

• diagnosed CD based on comprehensive clinical, colonoscopy, histopathological, laboratory, and radiographic examination results

Exclusion Criteria:

• rheumatoid arthritis, systemic lupus erythematosus, intestinal tuberculosis, ischemic enteritis, radiation enteritis, tumors, etc.

There was no statistically significant difference in the gender ratio, average age, and proportion of smokers between CD group and normal control group. All study subjects are from the Zhejiang Han population who are not related by blood.