In vitro immune modulation of polymorphonuclear leukocyte adhesiveness by sodium fluoride.

Abstract

We investigated the influence of sodium fluoride on polymorphonuclear leukocyte (PMN) adhesiveness in a healthy subject with low serum levels of fluoride. The PMN were separated from venous blood, and the percentages of adhered and unadhered cells were determined in vitro in plastic culture plates. The cells were cultured with five different fluoride concentrations ranging from 6.25 10(-2) microM to 4.0 microM in the presence and absence of autologous serum. PMN adhesiveness in both the presence and in the absence of autologous serum was 98.5%; the addition of fluoride had no effect on the results in the absence of serum. However, in the presence of autologous serum, PMN adhesiveness decreased significantly with the addition of fluoride (P < 0.05) from 0.5 microM. The decrease was smaller (1.1%) at a concentration of 0.125 microM, and larger at 12 times this concentration of fluoride (52.7%). We conclude that sodium fluoride reduces PMN adhesiveness in a dose-dependent manner. The effect is not direct, but should be modulated by a seric factor.