Serum level of soluble endoglin in active and inactive Crohn's disease

Endoglin is a transmembrane glycoprotein associated with endothelial dysfunction. Elevated serum levels of its soluble form (sENG) have been reported in conditions such as atherosclerosis and systemic inflammation. However, to the best of our knowledge, sENG level has not yet been evaluated in patients with Crohn's disease (CD). This study assessed serum sENG concentration and its association with clinical characteristics and various laboratory parameters in patients with active and inactive CD. A total of 48 patients with CD were enrolled in the study, 17 patients with inactive disease (Crohn's Disease Activity Index (CDAI) <150 points; median age: 34 years) and 31 patients with active disease (CDAI ≥150 points; median age: 36 years). Complete blood count, C-reactive protein (CRP), albumin, creatinine, ferritin, liver function tests, and sENG were measured. In our study, the serum level of sENG was significantly higher in patients with active CD compared to those with inactive disease (median, IQR, 0.63 (0.38-0.89) ng/ml vs 0.27 (0.2-0.48) ng/ml, p=0.004). No significant differences in sENG level was observed based on age at diagnosis, disease location, disease behavior, or current treatment. A significant negative correlation was found between sENG level and hemoglobin (r= -0,323, p=0.025), hematocrit (r= -0.286, p=0.049), and albumin concentrations (r= -0.386, p=0.011), while a positive correlation was observed with platelet count (r=0.302, p=0.037), CRP (r=0.316, p=0.028) and CDAI. A serum sENG concentration of 0.29 ng/ml was identified as the optimal predictive cutoff value for disease flare, with an area under the curve (AUC) of 0.748, sensitivity of 83.9%, and specificity of 64.7%. We found that serum level of sENG was significantly higher in patients with active CD and we conclude that SENG may serve as a potential marker of disease activity. However, further studies are needed to confirm this association.