Plasma α2-HS glycoprotein concentrations in patients with acute myocardial infarction quantified by a modified ELISA

Background: Human alpha(2)-HS glycoprotein (alpha(2)-HSG) is synthesized and secreted by the liver into circulation. Plasma concentrations of alpha(2)-HSG decrease significantly following infection, inflammation and malignancy. Since increased plasma concentrations of C-reactive protein are observed in patients with acute myocardial infarction (AMI), we hypothesized that plasma concentrations of alpha(2)-HSG would decrease during the initial phase of AMI and begin to increase in the recovery phase. Methods: Twenty patients diagnosed with AMI were recruited for the study. A sensitive and specific ELISA was developed to assay alpha(2)-HSG concentrations in plasma. Results: In AMI patients, plasma alpha(2)-HSG concentrations were decreased (281.3 +/- 25.8 mg/I, ranging from 132 to 489 mg/l on admission) compared to healthy individuals (312.3 +/- 9.9 mg/l, ranging from 210 to 450 mg/l) (P= 0.142). Interestingly, 40% of AMI patients demonstrated alpha(2)-HSG concentrations below 200 mg/l compared to none in the healthy control group. During the recovery period, alpha(2)-HSG concentrations begin to increase, with a mean +/- SEM of 290.1 +/- 22.1 mg/l. Regression analysis comparing plasma alpha(2)-HSG concentrations on admission to concentrations on discharge showed a significant positive correlation in matched-pair patient samples (P<0.01, r=0.45). Conclusions: We conclude that, in contrast to C-reactive protein, α(2)-HSG functions as a negative acute phase protein in AMI patients. Plasma α(2)-HSG concentrations start to decrease within a few hours after the onset of AMI and return to near normal concentrations during the recovery period (5-7 days after AMI). (C) 2002 Elsevier Science B.V. All rights reserved.