Introduction
The pathogenesis of ulcerative colitis (UC) involves complex immune responses, including Th1, Th2, and Th17 pathways, and is characterized by substantial heterogeneity. Cytokine profiling may contribute to understanding individual disease mechanisms and guiding personalized therapeutic strategies; however, its clinical application remains limited due to technical complexity. This study aimed to investigate whether endocytoscopic and histopathological findings correlate with mucosal cytokine expression levels and could serve as surrogate markers.
Aims & Methods
Thirty-five patients with UC receiving treatment at our institution were enrolled. Endocytoscopy (ultra-magnifying endoscopy) was performed in all patients, and the findings were classified according to the Endocytoscopic Classification system (EC classification: EC-A, EC-B, EC-C, EC-D). Mucosal biopsies were obtained from the most inflamed areas identified during endocytoscopy. Histological evaluation included the Matts histological grade and assessments of neutrophil, eosinophil, and lymphocyte infiltration; goblet cell depletion; crypt distortion; and epithelial damage, each graded on a four-point scale (absent, mild, moderate, severe). mRNA expression levels of cytokines (IFN-γ, TGF-β1, TNF-α, IL-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13, IL-17, and IL-23) were quantified using RT-PCR. Statistical analyses were performed to assess correlations between endocytoscopic/histopathological findings and cytokine expression levels.
Results
The median age of participants was 44 years (IQR: 35–57), with 24 males and 11 females. Disease types included pancolitis (n = 16), left-sided colitis (n = 14), and proctitis (n = 5). The median Mayo score was 1 (IQR: 0–5). EC classification scores showed significant positive correlations with the expression levels of IL-1β, IL-6, IL-8, IL-13, IL-17, and IL-23 (Spearman’s rank correlation, p < 0.05; r = 0.555, 0.526, 0.584, 0.441, 0.422, and 0.449, respectively). Similarly, Matts histological grades were significantly correlated with the expression of IFN-γ, IL-1β, IL-6, IL-8, IL-13, IL-17, and IL-23 (p < 0.05; r = 0.493, 0.756, 0.692, 0.730, 0.656, 0.623, and 0.448, respectively). Histopathological features—including neutrophil and lymphocyte infiltration, goblet cell depletion, epithelial damage, and crypt distortion—were significantly associated with the expression of IFN-γ, IL-1β, IL-6, IL-8, IL-13, IL-17, and IL-23. Additionally, eosinophil infiltration was positively correlated with the expression levels of IL-1β, IL-5, and IL-13.
Conclusion
This study demonstrates that endocytoscopic and histopathological indicators of inflammation are associated with mucosal expression levels of several cytokines—particularly inflammatory and Th17-related cytokines—in patients with ulcerative colitis (UC). These findings suggest that such evaluations may serve as surrogate markers, potentially improving disease assessment and informing therapeutic decision-making.