Background and objective: The plasminogen activating system is a protease/inhibitor system central to extracellular matrix remodeling with a suggested role in periodontal disease pathology. A few studies have reported polymorphisms in the genes of plasminogen activator inhibitors to be associated with periodontal disease severity. Two gene polymorphisms - a BamHI restriction fragment length polymorphism in the urokinase plasminogen activator gene (uPA) and a HindIII restriction fragment length polymorphism in the plasminogen activator inhibitor type 1 gene (PAI-1) - have been associated with conditions having a vascular component, and our objective was to assess the association of these gene polymorphisms with alveolar bone loss in chronic periodontal disease of adults.
Material and methods: Genotype was determined by polymerase chain reaction amplification of whole blood, pertinent histories were obtained by interview, and alveolar bone loss was assessed from current radiographs.
Results: In 77 elderly patients with a normal distribution of alveolar bone loss, we demonstrated a significant association between levels of alveolar bone loss and these polymorphisms in the uPA and PAI-1 genes. Controlling for the contributions of smoking or diabetes to periodontal bone loss, estimated odds ratios for predicting lower levels of alveolar bone loss, associated with a greater degree of periodontal health, were strongest when defined by the concurrent presence of a homozygous urokinase plasminogen activator genotype and the nuclease-sensitive plasminogen activator inhibitor type 1 (HindIII) allele (odds ratio = 2.6; 95% confidence interval: 5.8-1.3).
Conclusion: The urokinase plasminogen activator (BamHI) and plasminogen activator inhibitor type 1 (HindIII) genotypes may serve as useful markers for heritability of bone loss associated with periodontal disease.