Genetic variation of IL-12B (+1188 region) is associated with its decreased circulating levels and susceptibility to Type 2 diabetes

Background: Type 2 diabetes mellitus is one of the most common types of endocrine disease and the immune system plays a predominant role in its pathogenesis. Aims: The present study aimed to examine known gene polymorphisms within IL-12B (+1188) region and its circulating serum levels in Type 2 diabetic patients from the southeastern region of Iran and compare them with unrelated controls. Materials & methods: In this clinical study, peripheral blood was collected from 114 Type 2 diabetic patients and 100 healthy controls. Serum levels of IL-12B were measured by ELISA. Genomic DNA was extracted from peripheral blood samples and polymorphisms at the +1188 position of the IL-12B gene were assessed using PCR restriction fragment-length polymorphism. Results: Our findings demonstrated that the AA genotype and the A allele of IL-12B were increased significantly in Type 2 diabetic patients when compared with controls. Our results also showed that the circulating levels of IL-12B were significantly decreased in Type 2 diabetic patients when compared with controls. Conclusion: According to the findings of the current study, we concluded that IL-12B and its +1188 polymorphism may play a prominent role in the pathogenesis of Type 2 diabetes. Further replicative investigations using a larger sample size are essential to identify additional IL-12B genetic variants associated with a risk of Type 2 diabetes.