Human leukocyte antigens are associated with salivary level of active MMP-8

Objectives: This case control study examined the associations of HLA antigens and periodontitis with the salivary level of active MMP-8 (aMMP-8). Materials and Methods: A total of 202 subjects, registered as Swiss bone marrow donors, participated in the study. HLA-A, -B, and -C types were determined by serology or PCR. Saliva samples were collected from subjects, followed by a periodontal examination. The salivary level of aMMP-8 was determined with immunofluorometric assay. Results: The mean salivary level of aMMP-8 was directly comparable to the grade of periodontitis and increased from healthy to mild/moderate to severe (125.0 +/- 132.1, 200.6 +/- 170.2, 290.1 +/- 202.3 ng/ml; p < 0.001 between each group, respectively). The only association between the HLA types and the salivary level of aMMP-8 was observed in subjects with HLA-A11. Subjects with healthy periodontium and HLA-A11 had a lower level of aMMP-8 (49.2 +/- 32.5 ng/ml) compared with subjects without HLA-A11 (123.6 +/- 119.2; p = 0.048). Among subjects with periodontitis, a higher level of aMMP-8 (394.2 +/- 255.6 ng/ml) was observed in subjects with HLA-A11 compared with subjects without HLA-A11 (201.1 +/- 146.1 ng/ml; p < 0.002). This finding was statistically significant also after adjusting for sex, age, smoking, tooth brushing and the number of medications (p < 0.05). Conclusions: HLA-A11 is associated with the salivary level of aMMP-8 which contributes to the subject's immune and inflammatory response in periodontium.