Investigating Association Level of CXCL12 with its SDF-1α 3'A Genetic Variant and CXCL10 with its 1443 Promoter Polymorphism in Type-1 Diabetes

Background: Type-1 Diabetes Mellitus (T1DM) is an autoimmune and heterogeneous disorder. In the present study, we aimed to examine whether there exists an association between serum CXCL10 (IP-10) level and its promoter polymorphism at position-1443 along with CXCL12 and its known SDF-1 3' A genetic variant as an angiogenesis chemokine in T1DM patients.

Methods: Blood specimens were collected from 209 unrelated T1DM patients and 189 healthy subjects. The DNA samples were extracted from the subjects and analyzed for CXCL10 and CXCL12 polymorphisms using PCR-RLFP. The serum concentrations of CXCL10 and CXCL12 were also analyzed with ELISA.

Results: Following expert opinion and data analysis, we found significant differences between A/A, A/G, and G/G genotypes with A and G alleles of polymorphisms at position +801 (SDF-1α3'A) in CXCL12. No association was reported between CXCL10/-1443 promoter polymorphism and T1DM. In our assessment of promoter polymorphism, both T1DM patients and controls had GG genotypes in CXCL10/-1443. When patients were compared with controls, both serum CXCL10 and CXCL12 levels were found to be increased in type 1 diabetes with complications. Levels were not increased in patients without complications.

Conclusion: Both CXCL10 and CXCL12 play fundamental roles in T1DM pathogenesis. Only the CXCL12 3'A (SDF-1α3'A) polymorphism is possibly necessary for the pathogenesis of T1DM, while the CXCL10-1443 promoter polymorphism is not.