Genetic polymorphism in the tumour necrosis factor alpha gene (G-308A) is associated with persistent apical periodontitis in Brazilians

Aim: To investigate if there was an association between genetic polymorphisms in tumour necrosis factor (TNF)-alpha and its receptors TNFRSF1A and TNFRSF1B with persistent apical periodontitis (PAP) in Brazilian subjects. Methodology: Patients who had pulpal necrosis and apical periodontitis at the time of treatment, with at least 1-year of follow-up after non-surgical root canal treatment were recalled. Three hundred and seventy eight subjects were included, 150 subjects with signs/symptoms of PAP and 228 subjects with root canal-treated teeth exhibiting healthy perirradicular tissues (healed). Genomic DNA was extracted from saliva and used for TNF-alpha (rs1800629), TNFRSF1A (rs1800693) and TNFRSF1B (rs1061622) genotyping by real-time PCR. Genotypes and alleles frequencies were evaluated by c2 or Fisher's exact tests and odds ratios were implemented (alpha = 5%). Results: The genetic polymorphism in TNF-alpha (rs1800629) was associated as a protective factor for the development of PAP (p < .05), once subjects who presented at least one allele A (AA+AG X GG), had a higher chance to lesion repair (p < .05). The polymorphisms rs1800693 and rs1061622 in TNF receptors (TNFRSF1A and TNFRSF1B, respectively) were not associated with the development of PAP (p > .05). Conclusions: The observed results demonstrate that polymorphism in TNF-alpha but not in its receptors is associated with PAP.

Automated summary

The study found that genetic polymorphisms in TNF-α are associated with persistent apical periodontitis (PAP), while polymorphisms in its receptors (TNFRSF1A and TNFRSF1B) are not associated with PAP.