Interleukin-1 gene polymorphism and periodontal status - A case-control study

Objectives: This case-control study examined polymorphisms at the interleuk in-1 gene in relation to periodontal status, subgingival bacteria and syste mic antibodies to periodontal microbiota. Methods: 132 periodontitis patients were age- and gender-matched with 73 pe riodontally intact controls. Full-mouth clinical assessments of the periodo ntal tissues were performed. Subgingival plaque samples (2440 in total) wer e analyzed by genomic DNA probes, and serum IgG antibodies to periodontal m icrobiota were assessed by an immunoassay. Polymorphisms in the IL-1A gene at position +4845 and the IL-1B gene at position +3953 were studied by PCR. A composite positive genotype was defined as at least one rare (#2) allele present at each locus. Results: No skewed distribution of the composite genotype was observed betw een cases and controls (45.2% vs 41.7%). In cases, both the composite genot ype and the number of #2 alleles were positively correlated with the severi ty of attachment loss, No relationship between genotype and subgingival mic robial profiles was observed. Genotype positive patients revealed both over all loner serum antibody levels and specific titers against selected bacter ia. Conclusions: The composite genotype failed to distinguish between periodont itis patients and controls but correlated in patients with the severity of the disease and the antibody responses to periodontal microbiota.