Genetic variants of TNF-α and PTPN22 and their association with Hashimoto's thyroiditis in patients with chronic spontaneous urticaria from the Colombian Caribbean.

OBJECTIVE

To evaluate the association of TNF-α promoter polymorphisms (rs361525, rs1800629) and the PTPN22 rs2476601 variant with the coexistence of CSU and HT in an admixed Caribbean Colombian population.

METHODS

A retrospective case-control study was conducted in 86 patients with confirmed CSU (45 with CSU-alone and 41 with CSU+HT). Single-nucleotide polymorphism (SNP) genotyping was performed using TaqMan® assays. Hardy-Weinberg equilibrium (HWE), genotype, and allele frequencies were analyzed using chi-square tests and logistic regression models.

RESULTS

The PTPN22 G allele showed a protective association in the CSU+HT group (OR: 0.02, 95% CI: 0.00-0.49; p = 0.015). While TNF-α SNPs conformed to HWE, PTPN22 deviated in the CSU+HT group due to the complete absence of AG heterozygotes. No significant associations were found between TNF-α polymorphisms and HT, though the TNF-α rs361525 G allele exhibited a near-significant trend (p = 0.061). The GG genotype was predominant across all evaluated SNPs.

CONCLUSION

In this admixed Caribbean Colombian study, we observed a hypothesis-generating association between the PTPN22 rs2476601 G allele and lower odds of concomitant HT in CSU patients. Larger, adequately powered studies incorporating rigorous ancestry adjustment are required to confirm this finding.