Mannose-binding lectin gene polymorphism in relation to periodontal infection

Area of Science:

• Immunogenetics
• Periodontology
• Microbiology

Background:

• Mannose-binding lectin (MBL) is crucial for innate immunity.
• MBL deficiency often results from mutations in the MBL2 gene.
• MBL plays a role in the host's response to periodontal pathogens.

Purpose of the Study:

• To investigate MBL2 gene polymorphisms.
• To assess the relationship between MBL2 variants and salivary markers of periodontal inflammation and tissue destruction.
• To examine the association with periodontitis-associated bacteria: Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis.

Main Methods:

• Genotyping of MBL2 by pyrosequencing in 222 subjects (40-60 years old, ≥20 teeth).
• Subjects categorized into generalized periodontitis (80), localized periodontitis (65), and periodontitis-free (77) groups.
• Salivary analysis for A. actinomycetemcomitans, P. gingivalis, IL-1β, MMP-8, and TIMP-1 levels.

Main Results:

• MBL2 genotypes: A/A (69.4%), A/O (26.6%), O/O (4%).
• In A. actinomycetemcomitans-positive subjects with MBL2 variants (A/O or O/O), elevated IL-1β and decreased TIMP-1 were observed.
• These subjects also showed a higher MMP-8/TIMP-1 ratio and increased pocket teeth compared to those without A. actinomycetemcomitans.

Conclusions:

• MBL2 variants may predispose individuals to more severe periodontal inflammation and destruction.
• The presence of A. actinomycetemcomitans exacerbates periodontal disease in individuals with variant MBL2.
• This highlights the interplay between genetic predisposition and bacterial infection in periodontitis pathogenesis.