The influence of plasma and serum on the chemotactic response to plaque

The chemotactic response of human PMNL cells to: 1) normal plasma or serum, 2) heat inactivated plasma or serum, 3) autologous plaque mixed with saline, 4) autologous plaque mixed with a complement source (plasma or serum), and 5) autologous plaque mixed with heat inactivated plasma or serum was examined using the Boyden chamber technique. The results indicated serum to be more chemotactic than plasma but that the chemotactic properties of both were heat labile. The addition of autologous plasma to plaque enhanced the chemotactic response in some subjects and inhibited the response in others. Similarly, heat inactivated plasma mixed with autologous plaque suspension strongly inhibited the chemotactic response in 30 % of the subjects tested. The mechanism of this inhibition is unknown but cross matching experiments between individuals indicated that this effect was transferable by plasma.