Low serum level of 1,25(OH)2 D is associated with chronic periodontitis.

BACKGROUND AND OBJECTIVES: Vitamin D has been studied primarily for its involvement in calcium and phosphate absorption and bone metabolism. The active form of vitamin D-1,25(OH)2 D-has also been investigated for its immune modulatory properties. We explored associations between serum levels of 25(OH)D and 1,25(OH)2 D and periodontal health. SUBJECTS AND METHODS: This case-control study included 55 subjects with chronic periodontitis (cases) and 30 periodontally healthy subjects (controls). Their serum levels of 25(OH)D, 1,25(OH)2 D, ultrasensitive C-reactive protein and high-density lipoprotein cholesterol were determined. Associations between vitamin D and periodontal health status were studied using logistic regression analysis. RESULTS: A statistically significant association was found between serum 1,25(OH)2 D level and periodontal health status; in that subjects with a low 1,25(OH)2 D were more likely to belong to the periodontitis group (OR = 0.97, 95% CI = 0.95-1.00). There was practically no association between 25(OH)D level and periodontal health status. CONCLUSION: In this case-control study low serum 1,25(OH)2 D level appeared to be associated with periodontitis, which was in line with the previously reported associations between serum 1,25(OH)2 D levels and other inflammatory diseases. Whether this association is causal in nature, remains to be confirmed in future studies.

Serum sCD14, polymorphism of CD14(-260) and periodontal infection.

BACKGROUND AND AIMS: CD14 is a co-receptor involved in the recognition of Gram-negative and positive bacteria. Infections are known to influence serum sCD14 levels, and CD14 gene promoter polymorphism (CD14 C-260T) has been reported to be associated with many infectious diseases. Our aim was to investigate whether serum sCD14 concentration is associated with periodontal infection and the CD14(-260) genotype. SUBJECTS AND METHODS: The periodontal status of 56 subjects with chronic periodontitis and 28 controls was clinically examined. Serum sCD14 concentration was analyzed using ELISA and CD14(-260) genotype using polymerase chain reaction (PCR). RESULTS: The mean concentration of sCD14 in serum was significantly higher in subjects with periodontitis than in control subjects (4.9 microg ml(-1)vs 3.8 microg ml(-1), P < 0.001). Serum sCD14 concentration associated significantly with the extent of advanced periodontal disease. In a regression analysis including both subject groups, the CD14(-260) genotype was a significant determinant for serum sCD14 concentration. After stratification by periodontal health status (periodontitis vs controls), the influence of the CD14(-260) genotype on serum sCD14 concentration was seen only in the control group. CONCLUSIONS: Periodontal infection is associated with the serum concentration of sCD14. Moderate to severe periodontal infection overshadows the influence of the genotype on serum sCD14 concentration.

Basement membrane carbohydrate as a target for bacterial adhesion: binding of type I fimbriae of Salmonella enterica and Escherichia coli to laminin.

Adherence of type-1-fimbriate Salmonella enterica and Escherichia coli to immobilized proteins of the extracellular matrix and reconstituted basement membranes was studied. The type-1-fimbriate strain SH401 of S. enterica serovar Enteritidis showed good adherence to laminin, whereas the adherence to fibronectin, type I, type III, type IV or type V collagens was poor. Only minimal adherence to the matrix proteins was seen with a non-fimbriate strain of S. enterica serovar Typhimurium. A specific and mannoside-inhibitable adhesion to laminin was exhibited by the recombinant E. coli strain HB101(pISF101) possessing fim genes of Typhimurium. Adherence to laminin of strain SH401 was inhibited by Fab fragments against purified SH401 fimbriae, and a specific binding to laminin, of the purified fimbriae, was demonstrated using fimbriae-coated fluorescent microparticles. Periodate treatment of laminin abolished the bacterial adhesion as well as the fimbrial binding. Specific adhesion to immobilized laminin was also shown by the type-1-fimbriate E. coli strain 2131 and the recombinant strain E. coli HB101(pPKL4) expressing the cloned type-1-fimbriae genes of E. coli. Adhesion to laminin of strain HB101(pPKL4) was inhibited by mannoside, and no adherence was seen with the fimH mutant E. coli HB101(pPKL5/pPKL53) lacking the fimbrial lectin subunit. The type-1 fimbriate strains also adhered to reconstituted basement membranes from mouse sarcoma cells and human placenta. Adhesion of strains HB101(pISF101) and HB101(pPKL4) to both basement membrane preparations was inhibited by mannoside. We conclude that type-1 fimbriae of S. enterica and E. coli bind to oligomannoside chains of the laminin network in basement membranes.

Penetration of fimbriate enteric bacteria through basement membranes: a hypothesis.

A mechanism for penetration of basement membranes by Escherichia coli is presented. The mechanism is based on the ability of the S fimbriae of meningitis-associated E. coli to bind to vascular endothelium and choroid plexuses in brain and to basement membranes. On the other hand, the S and the type 1 fimbriae of E. coli immobilize plasminogen and tissue-type plasminogen activator; this process generates proteolytic plasmin activity on the surface of fimbriate cells. Our hypothesis is that bacterium-bound plasma activity, directed to basement membranes through fimbrial binding, promotes bacterial penetration through basement membranes.