Objective  To investigate changes in plasma concentrations of interleukin-17A (IL-17A), interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) in patients with inflammatory bowel disease (IBD) and their clinical significance.

Methods A total of 75 patients with active IBD who visited the Department of Gastroenterology of the First Affiliated Hospital of Soochow University and the Department of Gastroenterology of Suzhou Hospital Affiliated to Nanjing Medical University between November 2022 and May 2024 were enrolled, including 24 patients with active ulcerative colitis (UC) and 51 patients with active Crohn’s disease (CD). In addition, 30 healthy volunteers were included as a healthy control group (HC group). Plasma concentrations of IL-17A, IFN-γ, and TNF-α were measured in each group using ELISA, and relevant statistical analyses were performed.

Results Compared with the HC group, plasma concentrations of IL-17A, IFN-γ, and TNF-α were all increased in patients with IBD (all P ＜ 0.05). In patients with active CD, plasma concentrations of IL-17A and TNF-α, and in patients with active UC, plasma concentration of TNF-α, were correlated with the severity of the disease. In CD patients, plasma IL-17A and TNF-α concentrations were positively correlated with the Crohn’s Disease Activity Index (CDAI) score (r_s = 0.413 and 0.319, respectively, both P ＜ 0.05). In UC patients, plasma IL-17A and TNF-α concentrations were positively correlated with the modified Mayo score (r_s = 0.707 and 0.621, respectively, both P ＜ 0.01).

Conclusion Plasma concentrations of IL-17A, IFN-γ, and TNF-α were all increased in patients with IBD compared with the HC group, and were correlated with CDAI scores and modified Mayo scores.