Influence of acute phase proteins on erythrocyte aggregation. Weng, Xiaoduan, Guy Cloutier, Raymond Beaulieu, and Ghislaine O. Roederer. Laboratory of Biomedical Engineering, Clinical Research Institute of Montreal, 110 Avenue des Pins Ouest, Montr[acute]eal, Qu[acute]ebec, Canada, H2W 1R7, Division of Oncology and Hematology, H[circumflex]otel-Dieu of Montreal Hospital, Qu[acute]ebec, Canada, Laboratory of Hyperlipidemia and Atherosclerosis, Clinical Research Institute of Montreal, Qu[acute]ebec, Canada
APStracts 3:0215H, 1996.
With the exception of fibrinogen, immunoglobulins, and albumin, little information is available on the effect of acute phase proteins on erythrocyte aggregation. The objective of this study was to investigate the effect of haptoglobin (Hp), C-reactive protein (CRP), ceruloplasmin (Cp), [alpha]1-acid glycoprotein ([alpha]1-AGP), and [alpha]1-antitrypsin ([alpha]1-AT) on the aggregation kinetics and shear resistance of red blood cell aggregates. Using a scattered laser light analysis system, the effect of adding sequentially these proteins in blood samples of 20 healthy individuals was investigated at a constant hematocrit (0.40) and temperature (37 degrees C). The original plasma concentration of all these proteins was measured on the control samples and kept unchanged while increasing the concentration of the protein tested. No effect on erythrocyte aggregation was observed for [alpha]1-AGP, [alpha]1-AT, and Cp at mean plasma concentrations of 2.85 g/l, 3.97 g/l, and 2.43 g/l, respectively. The effect of varying the plasma concentration of Hp (2.78, 3.89 and 4.99 g/l), CRP (0.116, 0.285 and 0.438 g/l), and Cp (2.73, 4.40, 6.06, 7.72 and 9.39 g/l) was specifically investigated. The addition of different concentrations of Hp showed a significant progressive increase of the aggregation kinetics compared to controls. An elevation of the shear resistance of the aggregates was found for CRP at the concentration of 0.438 g/l. By increasing the concentration of Cp over the physiological levels found in human, the aggregation kinetics and the adhesive forces between red cells were significantly increased. In Discussion, the molecular mass of the acute-phase proteins, their configuration, and the presence of specific receptors on the red blood cell membrane are postulated as possible factors influencing the aggregation kinetics and the adhesive forces between red cells.

Received 12 February 1996; accepted in final form 6 May 1996.
APS Manuscript Number H1036-6.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 June 96