INCREASED ADHESION OF PERIPHERAL-BLOOD NEUTROPHILS FROM PATIENTS WITHLOCALIZED JUVENILE PERIODONTITIS

Adhesion of peripheral blood neutrophils from 5 patients with localize d juvenile periodontitis (LJP) and age- and gender-matched healthy con trols was measured using a semi-automated 96-well microtiter plate ass ay method. Both unstimulated and formyl-methionyl-leucyl-phenylalanine (FMLP, 10-1000 nM)-stimulated neutrophils from LJP patients showed in general higher adhesion than did their controls. After 15-60 min incu bation with 100 and 1000 nM FMLP the numbers of adherent cells were si gnificantly (p<0.05), 2.1-2.6-fold higher in LJP patients than in cont rols. Neutrophils from these LJP patients showed also enhanced respira tory burst activity in response to unopsonized zymosan stimulation. To test whether a decrease in intracellular diacylglycerol (DAG) kinase activity could account for the increased neutrophil adhesion of LJP pa tients normal neutrophils were treated with R59949 (10 mu M), a DAG-ki nase inhibitor. Both unstimulated and FMLP-stimulated normal neutrophi ls showed significantly (p<0.05) enhanced adhesion after R59949-treatm ent. Taken together, our data indicate that neutrophils from the 5 LJP patients investigated here exhibit 2 parallel hyperactivities, namely increased adhesion and enhanced production of reactive oxygen species . Furthermore, our present and previous (Hurttia et al., J Periodont R es 1997; 32: 401-407) results suggest that the observed neutrophil fun ctional abnormalities in some LJP patients may be associated with decr eased cellular DAG-kinase activity. It is proposed that the hyperadher ent and -active neutrophils may promote the development of LJP by caus ing tissue damage in the periodontium.