Abstract
OBJECTIVE: The Interleukin-1 receptor antagonist (IL1-Ra) is initiated to terminate the acute pro-inflammatory event and prevent chronic inflammation from damaging healthy cells. We aim to draw the attention of IL1-Ra (VNTR) gene polymorphism and determine whether IL1-Ra confer susceptibility to type 1 diabetes mellitus (T1DM) and evaluate the genotype and allele distribution of IL1-Ra gene in a Saudi population.
PATIENTS AND METHODS: Case control study included (100) T1DM Saudi children, plus 102 healthy unrelated individuals as control group. They were evaluated for variable number of tandem repeat (VNTR) of IL1-Ra gene polymorphism. Polymerase chain reaction amplification of VNTR of 86bp in intron 2 of IL1-Ra was performed.
RESULTS: A1A1 and A1A2 genotypes with alleles A1 and A2 frequency were the most common both in cases and controls (healthy population); prevalence (28%, 56% & 57.8%, 39.2% respectively) and (58%, 38% and 77.5%, 22.5% respectively). In addition IL1-Ra gene polymorphism had higher risk significantly different between diabetic children and controls. (A1/A2) genotype had higher frequency statistically significant in DM patients than controls [56% vs. 39.2%, p < 0.02] and had twice time risk [OR = 1.97, 95% CI = 1.1-3.4, p < 0.02]. With further stratification, there was strong association between diabetic patients carriage IL1-Ra (A2) allele and controls [38% vs. 22.5%, p = 0.001] which had higher risk [OR = 2.11, 95% CI = 1.4-3.2, p = 0.001] for susceptibility of diabetes.
CONCLUSIONS: This study emphasizes a positive association between IL1-Ra (VNTR) polymorphism and DM among Saudi children. This may suggest that (A2) allele may play important role in disease susceptibility.