## 4 Discussion
### Relationship between Profile of Proinflammatory Mediators and Disease Activity  
In this research, we analyzed the correlation between the assessed serum proinflammatory mediators (E- and P-selectin, CCL2, IL-1\(\alpha\), IL-12p70, TNF-\(\alpha\)) and disease activity to identify the utility of these biomarkers in monitoring the course of [PERSON]'s disease and ulcerative colitis. Statistical analyses revealed a significant moderate correlation between the serum level of CCL2 and TNF-\(\alpha\) with disease activity, but only in patients with ulcerative colitis, while no such relationship was noted in the group of patients with CD. The relationship between the Mayo score and CCL2 serum level in the UC group may be related to the dominance of the Th2 phenotype observed during ulcerative colitis. Not only is CCL2 engaged in the differentiation of naive T cells into Th2 cells, but it also stimulates these cells to release Th2-related proinflammatory cytokines such as IL-4 [9]. The obtained results can be compared to the study conducted by [PERSON] et al. [23], in which the researchers analyzed the changes in CCL2 expression in the serum and intestinal tissue collected from patients with UC during anti-inflammatory biological treatment (with infliximab). In the group of patients responding to the implemented treatment, the expression of CCL2 decreased significantly after 14 weeks of therapy in both the serum and intestinal tissue, whereas no such difference was noted in the group of non-responders. The results of our study and [PERSON] et al. 's study may indicate the use of serum CCL2 profiling in monitoring the activity of ulcerative colitis, as well as in assessing the effectiveness of the implemented biological treatment. The role of TNF-\(\alpha\) in the pathogenesis of both CD and UC is well established. Due to its crucial role in the inflammatory process, numerous studies have shown an increased expression of TNF-\(\alpha\) in biopsies collected from patients with CD and UC [24]. Therefore, one of the aims of our study was to identify the utility of TNF-\(\alpha\) in assessing the disease activity. The obtained results presented a significant correlation between TNF-\(\alpha\) serum profile and Mayo score in the group of UC patients; however, the level of that cytokine did not correlate with disease activity in the CD group. This observation may indicate that the TNF-\(\alpha\) serum profile reflects the activity of the disease better in ulcerative colitis than in [PERSON]'s disease. Regarding the common use of anti-TNF-\(\alpha\) biological treatment during IBD, the measurements of TNF-\(\alpha\) might be beneficial in not only monitoring the disease activity but also the response to treatment at the same time. However, this hypothesis needs to be tested. Interrelationship between Analyzed Proinflammatory Mediators in Patients with Crohn's Disease and Ulcerative Colitis  
During inflammation, cytokines and chemokines present a unique network of interactions, where the local microenvironment affects the actions of not only immune cells but also inflammatory mediators. Therefore, in order to identify new mechanisms engaged in the initiation and development of the inflammatory process during [PERSON]'s disease and ulcerative colitis, we evaluated the relationship between the analyzed proinflammatory mediators, being E- and P-selectin, CCL2, IL-18, IL-12p70, and TNF-\(\alpha\). Significant correlations were noted, but only in the UC group in the case of E-selectin and IL-12p70; P-selectin and IL-1\(\alpha\); and TNF-\(\alpha\) with E-selectin, CCL2, and IL-1\(\alpha\). Considering the fact that P-selectin level did not correlate with platelet count in UC patients, the most likely explanation of the observed correlation between P-selectin and IL-1\(\alpha\) is the interactions of P-selectin with leukocytes.