Periodontitis increases chemiluminescence of the peripheral neutrophils independently of priming by the preparation method

OBJECTIVE: The aim was to investigate whether increased Fc gamma-receptor ( Fc gamma R)-induced chemiluminescence (CL) from peripheral neutrophils in p eriodontitis could be due to increased sensitivity to non-specific priming by the cell preparation. DESIGN: Two methods of preparation were used: (I) cells purified by density centrifugation and lysis of erythrocytes; and (2) cells in a leukocyte sus pension obtained by lysis of erythrocytes alone. METHODS: Neutrophils from 17 subjects with periodontitis and pair-matched h ealthy controls were studied by CL and flow cytometry (CD16, CD15 and CD11b ), RESULTS: Higher CL was found in the purified neutrophils, indicating higher non-specific priming by the Percoll density centrifugation. Priming with T NF alpha and lipopolysaccharide abolished this difference. The net effect o f specific priming was significantly lower in the purified neutrophils, ind icating a depletion of the priming sensitivity by the density centrifugatio n, Both preparations reduced CD15 in relation to whole blood, while there w as no difference between the two methods in any of the membrane markers. Th us, in both preparations, lysis alone changed the membranes to the same ext ent. Both methods gave nearly the same relative CL increase in the periodon titis patients as in the controls. CONCLUSION: There was no difference between the neutrophils from patients a nd controls in sensitivity to non-specific priming by the preparation metho d, The higher Fc gamma R-induced CL in patients with periodontitis is not r elated to such a non-specific priming by density centrifugation.