Inhibition of polymorphonuclear leucocyte phagocytosis by Porphyromonas gingivalis culture products in patients with adult periodontitis.

Porphyromonas gingivalis culture products and a purified trypsin-like protease (TLPase) from the organism were tested for their effects on the phagocytosis of P. gingivalis by polymorphonuclear leucocytes (PMN) from 16 patients with adult periodontitis and 16 healthy subjects in a case-control study. Both the culture products (p < 0.0001) and the TLPase (p < 0.0001) significantly inhibited PMN phagocytosis by both case and control samples. Culture products were significantly more inhibitory in both cases (p < 0.0019) and controls (p < 0.0198) than that TLPase. The case PMNs were significantly more susceptible to inhibition by culture products than the control PMNs (p < 0.0238). The data suggest that patients with adult periodontitis have PMNs that are more susceptible than normal to the inhibitory effects of P. gingivalis and might be at greater risk than healthy subjects to infection by this pathogen.