SOME FACTORS INFLUENCING HAEMAGGLUTINATION OF PENICILLIN-SENSITIZED ERYTHROCYTES

Abstract

Haemagglutination of penicillin-sensitized red cells by certain human sera is followed in a variable period of time by dispersal of the agglutinates. This is accompanied by loss of haemagglutinin activity from the supernatant fluid. Certain substances including albumin, sodium salicylate and glycerol tend to inhibit the haemagglutination reaction. The effect of the latter two substances suggests the possibility of a hydrogen bonding mechanism between the surface-adsorbed penicillin and antibody. Loss of activity from positive sera is a function of cell concentration, time of reaction and temperature. Both penicillin and the product of penicillin-penicillinase reaction inhibit the haemagglutinin activity of positive sera. Evidence is presented which suggests that the prosthetic group involved in penicillin-penicillinase combination differs from that in penicillin-antibody union. In addition, penicillin adsorbed to the red cell surface appears to be protected from the inactivating effect of penicillinase. Whether haemagglutinin for antibiotic-sensitized cells is of immune or nonimmune origin is, as yet, unestablished. It is possible to produce haemagglutinin in rabbits by injection of sensitized red cells and, after adsorption, such sera will agglutinate only antibiotic-sensitized cells. However, of seven sera causing haemagglutination of chloramphenicol-sensitized cells, six were from patients with no past history of chlor-amphenicol therapy. It is possible that this type of antibody may play a part in certain cases of unexplained haemolytic anaemia.