Serum amyloid A protein in very low density--and high density lipoproteins during the course of acute myocardial infarction.

In a preceding paper we reported on the detection and characterization of human serum amyloid A protein (SAA) in very low density lipoproteins (VLDL) and high density lipoproteins (HDL) of patients after acute myocardial infarction. Here we describe the time course of the occurrence of SAA in VLDL and HDL in the postinfarction period. SAA reached its maximum in VLDL and HDL approximately 53 h after the acute event. At the peak of the acute-phase response, SAA comprised as much as 38% of the total apoproteins of VLDL and HDL. SAA appeared at the same points in time and with nearly the same concentrations in VLDL and HDL. We conclude that SAA is not exchanged in plasma between lipoproteins of different densities and that this protein is secreted on its own by hepatocytes and not as a part of an already constituted lipoprotein particle.