In the multivariate analysis, three SNPs (i.e., interleukin 6 (IL6) rs2069840, C-X-C motif chemokine ligand 8 (CXCL8) rs4073, tumor necrosis factor (TNF) rs1800610) and two TNF CpG sites (i.e., c.-350C, c.-344C) were associated with pain group membership.
Of the 10 SNPs evaluated in LTA and PTGS2 genes, 3 were associated with pain severity (rs5277; rs1799964), social function (rs5277) and mental health (rs5275).
Controlling for these nongenetic covariates, we found that patients with CC genotypes for PTGS2 exon10+837T>C (rs5275) were at lower risk for severe pain (OR, 0.33; 95% CI, 0.11-0.97) and an additive model for TNFalpha -308GA (rs1800629; OR, 1.67; 95% CI, 1.08-2.58) and NFKBIA Ex6+50C>T (rs8904) was predictive of severe pain (OR, 0.64; 95% CI, 0.43-0.93).