Serum IgG responses to the cell envelope proteins (CEPs) from Capnocytophaga sputigena, Capnocytophaga ochracea, and Capnocytophaga gingivalis were examined in periodontally healthy and periodontitis subjects, both with and without type 1 diabetes (n = 60). Serum IgG responses to CEPs were determined by immunoblotting with biotin-goat anti-human IgG and an alkaline phosphatase-streptavidin system. Reactivity was analyzed by transmission densitometry, digitization, and computer manipulation. The patients with diabetes showed significantly (p < 0.01) fewer responses to 14 CEPs (from 81 to 10 kDa) from C. sputigena, 5 CEPs (from 90 to 17 kDa) from C. gingivalis, and the 27-kDa CEP from C. ochracea than in the non-diabetic group. The periodontitis patients showed significantly (p < 0.01) fewer responses to the 25-and 11-kDa CEPs from C. sputigena, the 125- and 17-kDa CEPs from C. gingivalis, and the 42-kDa CEP from C. ochracea than in the periodontally healthy group. HLA-DR4, HLA-DR53, and HLA-DQw3 were associated with periodontitis, while only HLA-DR4 was associated with diabetes (p < 0.02). Significant (p < 0.01) correlations were found between HLA-DR2 and IgG reactivity patterns associated with non-diabetics, and between HLA-DR4 and IgG reactivity patterns associated with diabetic and periodontitis subjects. These results indicate that both type 1 diabetics and periodontitis subjects have a depressed IgG antibody profile to Capnocytophaga, which may account for an increased susceptibility to periodontitis infection. Periodontitis in type 1 diabetes may be related more to the HLA-D type and altered immune function than to the diabetes itself.
ASJC Scopus subject areas