Genetic Polymorphism of IL-1A, IL-1B and TNFA Predicting the Presence of Periodontopathogenic Bacteria.

Background/

Objectives

Periodontitis is a chronic inflammatory disease characterized by complex interactions between periodontal pathogens and the host immune response. Pro-inflammatory cytokines, particularly interleukins, may influence bacterial colonization and disease expression, but their association with specific periodontal pathogens remains unclear. This study investigated the associations between single-nucleotide polymorphisms in IL-1A, IL-1B, and TNFA and the presence of key periodontopathogenic bacteria in patients from Croatia.

Methods

A cross-sectional study included 63 participants. Genotypes were determined, and subgingival plaque samples were analyzed for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola using real-time PCR. Multivariable logistic regression models assessed associations between cytokine gene polymorphisms and periodontopathogenic bacteria presence, adjusting for age, gender, smoking status, and the presence of systemic diseases.

Results

Among participants (median age 57.0 years, IQR 43.5-67.0; 58.7% female), P. intermedia (87.3%), T. forsythia (85.7%), and T. denticola (69.8%) were the most prevalent pathogens. The IL-1A CC genotype significantly increased the odds of P. gingivalis (OR = 5.54; p = 0.009) and T. denticola (OR = 3.77; p = 0.041) presence. The IL-1B CC genotype was independently associated with T. forsythia (OR = 8.48; p = 0.026). No significant associations were observed for TNFA polymorphism. Model performance ranged from moderate to good (AUC up to 0.89).

Conclusions

Genetic variants in IL-1A and IL-1B may influence periodontal bacterial colonization, while demographic and lifestyle factors showed limited impact. Further studies in larger cohorts are warranted.