Effect of levamisole on leukocyte adherence inhibition.

The leukocyte adherence inhibition test can serve as an in vitro model to investigate the cellular cooperation between T cells, monocytes and polymorphonuclear cells (PMN) but also the mechanism of cell adherence. Therefore, the effect of levamisole on the production of PMN activating factors by mononuclear cells and on cell adherence was studied with leukocytes from polyarthritic patients. Levamisole at concentrations ranging from 10(-9) M to 10(-4) M did not seem to affect the production of activating factors. These results differentiate levamisole from anti-inflammatory drugs which are potent inhibitors. On the other hand, levamisole increased markedly the adherence of leucocytes, mainly mononuclear cells, obtained from polyarthritic patients, or normal cells preincubated in a polyarthritic serum. This could be related to a direct effect of levamisole on the leukocyte membrane.