Antibodies to platelet-activating factor are associated with borderline hypertension, early atherosclerosis and the metabolic syndrome

Objective. Platelet-activating factor (PAF) is a phospholipid inflammatory mediator which is synthesized by a variety of cells, including monocytes an d endothelial cells, and PAF can be retained in activated endothelial cell membranes. Furthermore, PAF-like lipids are produced in other phospholipid membranes as in oxidized LDL. Atherosclerosis is a chronic inflammation in the artery wall, but little is known about the role of immune reactions in the early stages of development of cardiovascular disease. In the present s tudy we investigated if there are antibodies to PAF (aPAF) that may play a role in borderline hypertension and early atherosclerosis. Design. Seventy-three men with borderline hypertension (BHT) and 73 age-mat ched normotensive (NT) men (diastolic blood pressure 85-94 and <80 mmHg, re spectively) were recruited from a population screening programme. Antibody levels were determined by use of ELISA. Carotid intima-media (IM)- thicknes s and atherosclerosis was determined by B-mode ultrasonography. Results. BHT men had 49.3% higher aPAF levels of IgG class than NT controls (P = 0.0007). Antibodies to the biologically inactive lysoPAF did not diff er between BHT and NT group, aPAF levels were associated with LM-thickness in the left (P = 0.02) and right (P = 0.009) carotid artery. Furthermore, a PAF levels were enhanced in individuals with the metabolic syndrome (n = 44 ) as compared to those without (n = 102; P = 0.009), and also significantly associated with insulin levels (P = 0.02) and insulin resistance (P = 0.02 ). Conclusions. aPAF antibodies may reflect early vascular changes and thus se rve as novel markers for disease, and they may also be pathogenic, by elici ting an inflammatory reaction in the vascular wall.