Lipopolysaccharide-induced monocyte procoagulant activity, fibrinopeptide A, and PAI-I levels in persons with high or low levels of HDL-lipoprotein.

We have examined basal and stimulated monocyte procoagulant activity (PCA) in 10 persons with high HDL (1.62-2.47 mmol/L) and 10 persons with low HDL (0.43-1.29 mmol/L). Heparinized whole blood was incubated at 37 degrees C for 2 hours with 100 ng/ml of E. Coli lipopolysaccharide (LPS). Monocytes were isolated by density gradient centrifugation (purity > 70%), and PCA measured with a chromogenic peptide substrate assay. LPS-induced PCA was significantly higher in the high HDL group (p = 0.02), whereas basal levels were similar. Furthermore, the levels of total HDL, HDL2, as well as apo-A1 were all significantly correlated with LPS-induced monocyte PCA (p < 0.01, p < 0.01, and p = 0.03), whereas VLDL was inversely correlated (p = 0.02). PAI-I activity was significantly lower in the high HDL group (p < 0.01). LPS recovery in plasma after incubation, by LAL test, was significantly higher in the high HDL group (p = 0.02) and correlated to HDL2 (p = 0.04), and inversely correlated with triglycerides (p = 0.04). There was no significant difference between the two groups in plasma fibrinopeptide A (FPA) levels after LPS incubation.