Genetic polymorphism of interleukin-1 receptor antagonist in Type 1 diabetic children

Background Interleukin-1 receptor antagonist (IL1RN) variable number tandem repeats (VNTRs) are not fully understood in Type 1 diabetes mellitus (T1DM). It may affect IL1RN level and modify the disease risk. We aimed to study IL1RN VNTR polymorphism in Egyptian children with T1DM to clarify its potential role as a risk factor for T1DM and its effect on plasma IL1RN level. Methods A case-controlled study including 200 children (120 T1DM and 80 controls) was carried on. All children were subjected to genotyping of IL1RN VNTR. Plasma IL1RN was estimated by ELISA. Results The A1A2 and LS genotypes and A2 allele were significantly higher among cases compared to controls with increased T1DM risk (OR = 5.35, 2.56 and 3.13, respectively). The S allele was significantly elevated in cases compared to controls with 2.09-fold increased risk of having T1DM. The median plasma IL1RN significantly decreased in cases compared to controls. Within cases, IL1RN was significantly decreased in LS versus LL genotype. Conclusions There is a strong relationship between IL1RN VNTR and T1DM in Egyptian children. A1A1 genotype, LL genotype, A1 allele, and L allele were protective. A1A2 and LS genotypes, short (S), and A2 alleles were risk factors. IL1RN was decreased in T1DM, especially in LS genotype. Impact The relationship between IL1RN gene polymorphism and risk for T1DM among Egyptian children. Plasma IL1RN protein level in T1DM. Low IL1RN protein level in T1DM patients could be therapeutic targets for IL1RN medications in the future.