Fasting serum IL-6 levels were associated with variants in the ABO gene that determines blood group. ABO blood group has been found to be associated with a number of biomarkers such as von Willebrand factor levels, Factor VIII levels, thrombomodulin, TNF-α and ICAM-1 [52], [53], and in our case IL-6. The mechanism by which the A and B alleles affect these biomarkers is uncertain. In Caucasians with and without type 1 diabetes, a variant rs579459 near the ABO blood group gene accounted for 19% of the variance in E-selectin levels [52]; in our GWAS, this same variant was associated with IL-6 levels (p = 1.7E-07; Table S2).
