Background and study aim: Ulcerative colitis (UC) is a major type of inflammatory bowel disease (IBD). It is characterized by chronic inflammation of the large bowel occurring in genetically susceptible individuals exposed to environmental factors and typically, has a relapsing–remitting pattern. Neopterin serves as a marker of cellular immune system activation. This study aims to evaluate serum neopterin concentration as being a new biomarker for U.C. disease activity evaluation and to correlate it with some of the other markers of disease activity.
Patients  and methods: This study included 80 subjects, twenty apparently healthy volunteers as a control group (Group I) that included (13 male and 7 female, mean age ± SD 36.0 ± 12.6 y) and sixty patients with UC disease as a patient group (Group II) that included (46 male and14 female, Mean age ± SD 35.5 ± 9.6 y) Group II was subdevided into 20 patients recently diagnosed as active U.C. disease, 20 patients clinically in relapse and 20 patients clinically in remission. Colonoscope and calculation of Simple Ulcerative Colitis Clinical Activity Index Score (SCCAIS) was done for patients with U.C. Laboratory investigations as complete blood count (CBC), erythrocytic sedimentation rate (ESR), Complete liver and kidney function tests, Prothrombin time (PT), partial thromboplastin (PTT), International Normalizing Ratio (INR) and determination of serum neopterin level were done for all subjects.
Results: Serum neopterin level for the U.C. patients was (Mean ± SD= 18.6 ± 5.79, range= 6 – 40) which is highly significant than the control subjects with ( Mean ± SD = 5.9 ± 2.4, Range = 2.7 – 9.8). Serum neopterin concentration was positively correlated with SCCAIS ( r = 0.77 and P-value <0.001) that indicates a high significant relation between serum neopterin level and clinical active U.C. than in those whose disease was in clinical remission. Serum neopterin concentration was positivelycorrelated with ESR, TLC, platelet count and PT (r= 0.71, P-value <0.001), (r= 0.41, P-value <0.001), (r= 0.34, P-value <0.01) (r= 0.28, P-value <0.05) respectively, whereas negatively correlated with Hb. (r= -0.56, P-value = <0.001) and albumin (r= -0.35, P-value <0.01). There was statistically a high significant relation between serum neopterin level and endoscopic disease distribution (P-value <0.001) as serum neopterin level increases with the increasing of the U.C. disease extent.
Conclusions and Recommendations: Serum neopterin concentration can be used as a new biomarker for U.C. activity that could reliably distinguish between clinically active and inactive U.C., as well as, it can be a helpful tool in predicting the stage of the disease activity. Moreover, the degree of elevation in serum neopterin concentration may be in part related to location and extent of disease.