Impacts of circulating cytokine levels and gene polymorphism predisposition on type 1 diabetes mellitus.

ABSTRACT

PURPOSE: A wide range of cytokines has been demonstrated to be involved in the etiology of type 1 diabetes mellitus (T1DM). Gene polymorphisms may potentially contribute to a hereditary predisposition toward circulating cytokine levels as (high, intermediate, or low) since they can affect cytokine production or function. The aim of this study was to investigate the roles of cytokine levels and the association of single-nucleotide polymorphisms (SNPs) within cytokine genes with T1DM in Saudi children. METHODS: Totals of 91 well-characterized T1DM patients and 91 T1DM-free control subjects were enrolled in this study. RESULTS: The levels of 3 circulating cytokines (transforming growth factor [TGF]-ß1, interleukin [IL]-10, and IL-6) and 6 SNPs in 3 cytokine genes (TGF-ß1 [rs1800470 and rs1800471], IL-10 [rs1800896, rs1800871, and rs1800872], and IL-6 [rs1800795]) that contribute to genetic susceptibility were measured by enzyme-linked immunosorbent assay and polymerase chain reaction with sequence-specific primers. Our fn dings show that TGF-ß1 serum levels were signifcantly lower in the children with T1DM than in the control participants. The TGF-ß1 genotypes with a high-production phenotype were signifcantly less frequent and those with a lowproduction phenotype were signifcantly more frequent in the children with T1DM compared to the control participants. respectively. Furthermore, the IL-6 genotype frequency with low level of IL-6 production were signifcantly increased in the T1DM group compared to the control group. Moreover, our data demonstrated no appreciable diferences in circulating serum level or genotype and phenotype of IL- 10 between the patients and controls. CONCLUSION: This kind of measurement, which considers the prediction of T1DM, may be useful in assessing the severity of T1DM and susceptibility to T1DM among Saudi children.