STRONG IMPLICATION OF TNF-α AND IL8 GENES POLYMORPHISMS WITH AUTOIMMUNE THYROID DISEASES IN TUNISIAN POPULATION

Area of Science:

• Immunogenetics
• Endocrinology
• Molecular Biology

Background:

• Autoimmune thyroiditis (AITD), including Graves' disease (GD) and Hashimoto's thyroiditis (HT), are complex, genetically influenced conditions.
• Interleukin-8 (IL-8) and Tumor Necrosis Factor-alpha (TNF-α) are key inflammatory cytokines implicated in the pathogenesis of AITD.

Purpose of the Study:

• To investigate the association between genetic variations in IL-8 and TNF-α genes and the susceptibility to GD and HT in a Tunisian population.
• To analyze the correlation between specific gene polymorphisms, their protein expression levels, and the clinical manifestation of AITD.

Main Methods:

• Genotyping of TNF-α-238 G/A and IL-8+781C>T polymorphisms was performed using PCR-RFLP in 319 healthy controls, 230 HT patients, and 75 GD patients.
• Plasma levels of IL-1β and TNF-α were quantified to assess protein expression.

Main Results:

• The IL-8-781 T/T genotype and T allele were significantly more frequent in HT and GD patients compared to controls.
• The TNFA-238 G/A genotype and A allele were more prevalent in patients with hypertension (a common comorbidity) than in controls.
• No significant differences in plasma IL-8 and TNF-α levels were observed between AITD patients and healthy controls.

Conclusions:

• The IL-8-781C/T and TNFA-238 G/A polymorphisms are strongly associated with susceptibility to HT and GD in the Tunisian population.
• These genetic variations may represent important risk factors for developing autoimmune thyroid diseases in this specific ethnic group.