DEPRESSED PLASMA PLATELET-ACTIVATING-FACTOR ACETYLHYDROLASE IN PATIENTS PRESENTING WITH ACUTE MYOCARDIAL-INFARCTION

Cell membrane phospholipids, including platelet-activating factor (PAF ), participate in the pathogenesis of acute myocardial infarction (AMI ). The plasma level of PAF acetylhydrolase (AH) was determined in 18 p atients at presentation with AMI before thrombolysis, and the administ ration of adjunctive therapy, and compared with 13 healthy controls. P lasma levels of PAF-AH were significantly lower in the AMI patients (2 3.15 +/- 1.75 nmol/min/ml) than in the controls (30.43 +/- 2.13 nmol/m in/ml; p = 0.027). Considering normal plasma levels of PAF and lyso-PA F, and lack of evidence that anti-PAF antibodies are really beneficial in myocardial ischemia-reperfusion, it is reasonable to speculate tha t an inability of systemic PAF to 'turn on' PAF-AH enzymatic activity could contribute substantially to the observed events. Decreased PAF-A H activity in AMI patients may represent not a consequence, but rather , a risk factor for the development of acute coronary syndromes.