MULTIPARAMETER FLOW CYTOMETRIC ANALYSIS OF POLYMORPHONUCLEAR LEUKOCYTES IN WHOLE-BLOOD FROM PATIENTS WITH ADULT RAPIDLY PROGRESSIVE PERIODONTITIS REVEALS LOW EXPRESSION OF THE ADHESION MOLECULE L-SELECTIN (CD62L)

Numerous studies of polymorphonuclear leucocyte (PMN) function in pati ents with adult periodontitis, including rapidly progressive periodont itis, have yielded conflicting findings, perhaps because most of the a ssays were performed on PMNs that had been separated from whole blood by a variety of procedures. To avoid the problems associated with in v itro analysis of isolated cells, PMN function and antigen expression i n live whole unmanipulated blood of eight patients with rapidly progre ssive periodontitis were compared with those of age-, race-, and sex-m atched controls. Using multiparameter flow cytometry, a) L-selectin (C D62L) expression, b) cell size, and c) respiratory burst activity were measured in PMNs in whole blood immediately ex vivo and during incuba tion with Porphyromonas gingivalis and Staphylococcus aureus, By compa rison with PMNs from the control group, PMNs from the patient group ex pressed significantly lower levels of CD62L and had an increased size before stimulation. PMNs from both groups produced respiratory bursts similar to those of the two bacteria, but in both groups the responses to S. aureus were significantly greater than those to P. gingivalis, The significantly reduced expression of the adhesion molecule CD62L on PMNs in the patient group may lead to reduced tethering of neutrophil s at sites of inflammation and may partly explain the susceptibility o f these individuals to recurrent and severe periodontal infections. (C ) 1998 Wiley-Liss, Inc.