Serum Interleukin-33 level in Saudi children with inflammatory bowel disease.

Interleukin-33 (IL-33) is a cytokine that belongs to the interleukin-1 family and has been shown to be associated with mucosal inflammation. The aim of this study was to determine the serum level of IL-33 in children with ulcerative colitis (UC) and Crohn's disease (CD) and to correlate the level with the disease progression. In this cross sectional prospective study, we enrolled 50 children with IBD from KAUH, Jeddah, Saudi Arabia and 34 healthy control subjects between June 2012 and December 2012. Serum IL-33 was assessed by ELISA and CRP by immunonephelometric assay. Results from our study showed 32 CD and 18 UC patients included. The median age was 13.5 years for CD patients, 11.9 years for UC patients and 11.2 years for controls. Females constituted 53%, 66.7% and 59% of CD, UC and control subjects respectively. The median serum IL-33 in UC patients of 55.5 pg/mL was significantly higher than the median IL-33 level of 41 pg/mL in the healthy control (P=0.04) but no significant difference was found between the median IL-33 level in the sera of CD and the control group (P=0.7). A higher median IL-33 level was also found in active disease (P=0.03). In our cohort, the serum level of IL-33 was positively correlated with hs-CRP (r=0.48, P < 0.001). To conclude, our results support that serum IL-33 level is increased in children with UC as compared with control. Serum level is correlated with the disease activity; therefore it could be used as a potential biomarker for monitoring the severity of the disease in children with UC.

Replication of GWAS Coding SNPs Implicates MMEL1 as a Potential Susceptibility Locus among Saudi Arabian Celiac Disease Patients.

Celiac disease (CD), a gluten intolerance disorder, was implicated to have 57 genetic susceptibility loci for Europeans but not for culturally and geographically distinct ethnic populations like Saudi Arabian CD patients. Therefore, we genotyped Saudi CD patients and healthy controls for three polymorphisms, that is, Phe196Ser in IRAK1, Trp262Arg in SH2B3, and Met518Thr in MMEL1 genes. Single locus analysis identified that carriers of the 518 Thr/Thr (MMEL1) genotype conferred a 1.6-fold increased disease risk compared to the noncarriers (OR = 2.6; 95% CI: 1.22-5.54; P < 0.01). This significance persisted even under allelic (OR = 1.55; 95% CI: 1.05-2.28; P = 0.02) and additive (OR = 0.35; 95% CI: 0.17-0.71; P = 0.03) genetic models. However, frequencies for Trp262Arg (SH2B3) and Phe196Ser (IRAK1) polymorphisms were not significantly different between patients and controls. The overall best MDR model included Met518Thr and Trp262Arg polymorphisms, with a maximal testing accuracy of 64.1% and a maximal cross-validation consistency of 10 out of 10 (P = 0.0156). Allelic distribution of the 518 Thr/Thr polymorphism in MMEL1 primarily suggests its independent and synergistic contribution towards CD susceptibility among Saudi patients. Lack of significant association of IRAK and SH2B3 gene polymorphisms in Saudi patients but their association in European groups suggests the genetic heterogeneity of CD.