An anti-platelet activating factor antibody and its effects on platelet aggregation.

Production of antibodies against platelet activating factor (PAF) has been difficult, probably because of the low antigenicity of PAF, a low-molecular-weight phospholipid. We therefore used colloidal gold as a hapten carrier to produce anti-PAF polyclonal and monoclonal antibodies. Both antibodies reacted with PAF, lyso PAF, and L-alpha-lysophosphatidyl choline palmitoyl (lyso PCP), but they did not react phosphorylcholine chloride (PCC). Their affinities were higher for PAF than for lyso PAF and lyso PCP. When the antibodies were tested on PAF-induced platelet aggregation, they suppressed aggregation in a dose-dependent manner.