HLA-B27 transgenic rats are susceptible to accelerated alveolar bone loss

HLA-B27 transgenic rats exhibit generalized, severe inflammatory reactions and spontaneously develop arthritis and chronic gastrointestinal inflammation, as well as inflammatory lesions in other tissues. Our hypothesis was that HLA-B27 rats would also be susceptible to inflammatory periodontal disease, and therefore alveolar bone loss. The purpose of this investigation was to compare the naturally occurring alveolar bone loss in HLA-B27 and wild type rats.

Age- and sex-matched HLA-B27 transgenic (TG) and wild type Fischer 344 (WT) female retired breeders, and their age-matched male WT breeding mates, were examined for alveolar bone loss (ABL). Thirty-eight animals were used: twelve, 20, and 6 animals were 6, 8, and 12 months old, respectively. ABL was measured as the exposed root surface area (mm2) in the defleshed maxilla and mandible.

The coefficient of variation for replicate ABL measurements was 4.4%. For the 6- and 8-month age groups, ABL was significantly greater in TG rats compared to WT rats. The observed difference in ABL between TG and WT animals did not reach statistical significance for the 12-month age group. Within each of the two animal groups (TG and WT), ABL was significantly different between age groups. The ABL rate of TG female rats was 42% to 250% greater than that of WT female rats, depending on the age range examined.

HLA-B27 rats are susceptible to accelerated alveolar bone loss and could serve as an animal model of alveolar bone loss pathogenesis.