Investigations into the cellular contribution to host tissue proteases and inhibitors in gingival crevicular fluid.

Gingival crevicular fluid (GCF) was collected from chronic periodontitis patients using plastic micropipettes and coverslip smears stained with antibodies for leukocyte markers and Toluidine Blue for mast cells. The smears consisted of 70-80% granulocytes, 10-20% monocytes/macrophages, 5% mast cells and 5% T lymphocytes; no B lymphocytes were found. Proteases and inhibitors in GCF cells were investigated by enzyme cytochemistry using 2-methoxy-4-naphthylamine-linked peptide substrates and simultaneous coupling to Fast Blue B and immunocytochemistry using biotinylated secondary antibodies and an alkaline phosphatase/new fuchsin detecting system. Elastase was detected in granulocytes, cathepsin B in macrophages, dipeptidyl peptidases II and IV in a small proportion of macrophages, dipeptidyl peptidase IV in a few T lymphocytes, tryptase in mast cells and alpha-1-proteinase inhibitor and alpha-2-macroglobulin in some macrophages. GCF was also collected on filter paper strips and eluted into buffer for biochemical enzyme assays. Lysis of cells by addition of detergent to the elution buffer increased activities to 140-240% of control values. Removal of cells by centrifugation reduced measured activities to 1-30% of original figures; this effect was less if samples were pre-treated with detergent. Proteases from inflammatory cells therefore appear to make up most of the measured enzyme activity in GCF, and this association may explain recent correlations with periodontal disease progression.