EX-VIVO STUDIES OF POLYMORPHONUCLEAR NEUTROPHILS FROM PATIENTS WITH EARLY-ONSET PERIODONTITIS .3. CR3 AND LFA-1 EXPRESSION BY PERIPHERAL-BLOOD AND GINGIVAL CREVICULAR POLYMORPHONUCLEAR NEUTROPHILS

In this study, we assessed the LFA-1 (CD18/CD11a) and CR3 (CD18/CD11b) expression on peripheral polymorphonuclear leukocytes (PB-PMN) and cr evicular fluid polymorphonuclear leukocytes (CF-PMN), by subjects with a healthy periodontium (n=7), gingivitis (n=8), early-onset periodont itis (n=17) and adult periodontitis (n=8). Using flow cytometry analys is, the %s of CD18, CD11a and CD11b positive cells and the absolute nu mbers of fluorescent molecules were determined. No significant differe nce could be found among the 4 groups, for these 2 kinds of parameters , in PB-PMN or CF-PMN. However, a great difference could be noted betw een the results obtained from PB-PMN and those obtained from CF-PMN. T he %s of positive CF-PMN were significantly lower than those of PB-PMN for the 3 sub-units (p<0.001). The levels of CD18 and CD11b expressed by CF-PMN were higher than those expressed by PB-PMN and the differen ce was significant for CD11b (p<0.001). On the contrary, the level of CD11a expressed on CF-PMN was significantly lower than that expressed by PB-PMN (p<0.001). Hence, our current results show that early-onset periodontitis PMN can be quite normal and this fact is not surprising insofar as, in our study, these cells were perfectly functional and al l the subjects were in good health. We concluded that the analysis of the leukocyte adhesion receptors expression on PB-PMN does not appear useful for helping to establish a differential diagnosis between the d ifferent forms of periodontitis. However, the pattern of expression st udy on CF-PMN may permit a better comprehension of the local phenomena which are implicated in the defence of the periodontal tissues agains t oral micro-organisms.