Evolution of Haptoglobin Concentration in Serum during the Early Phase of Acute Myocardial Infarction

Abstract

is a haemoglobin-binding acute phase protein with three genetic types: Hp 1-1, Hp 2-1, Hp 2-2. We investigated 45 patients during the first 48 hours of acute myocardial infarction, and studied determinant factors and clinical correlates. Upon hospital admission, serum haptoglobin concentration was increased (1.95 ± 0.94 g/1, mean ± SD, P < 0.001) versus the reference population (0.97 ± 0.46 g/l, n = 107), independent of haptoglobin type: 1.84 ± 0.64 g/1 (Hp 1-1, n = 11) (P < 0.01), 1.98 ± 0.79 g/l (Hp 2-1, n = 25) (P < 0.001), 1.98 ± 1.58 g/l (Hp 2-2, n = 9) (P < 0.001). Moreover, during the first hours of hospitalization, a temporal lowering of haptoglobin was observed suggesting acute haemolysis, independent of the haptoglobin type. Minimal serum haptoglobin was reached 9.6 ± 5.8 hours after admission. The amplitude of the haptoglobin decrease correlated with initial serum haptoglobin (r = 0.78) and was more pronounced (P < 0.05) in men (0.53 ± 0.57 g/1) than in women (0.18 ± 0.17 g/1). Decrease of serum haptoglobin did not correlate with infarct size (based on creatine kinase-MB release). Out of the other acute phase proteins measured upon admission, only C-reactive protein was significantly increased (P < 0.05). During the next 36 hours, haptoglobin increased as a result of the acute phase response to myocardial injury. Our findings suggest that acute myocardial infarction is also preceded by an acute phase response, characterized by an initial high haptoglobin and followed by a temporal haptoglobin decrease due to haemolysis.

Haptoglobin Genotype Determines Myocardial Infarct Size in Diabetic Mice

“…Hemoglobin is a potent oxidant that is released from red cells because of hemolysis in the setting of IR and MI (21). We have proposed that the anti-oxidant and antiinflammatory functions of Hp may be attributed to its interaction with Hb.…”

Intraplaque Hemorrhage

“…We found that there was no increase in IL-10 in Hp 2 mice after one hour of reperfusion in this model but there was a 3-4 fold significant increase in IL-10 in the serum of the Hp 1 mice at one hour after the onset of reperfusion. While we have no direct proof that this process is mediated via Hp-Hb and CD163, hemolysis is known to occur rapidly after ischemia-reperfusion as demonstrated by an acute fall in Hp concentrations [76]. [19] Kumamoto, M., Nakashima, Y. and Sueishi, K. …”

Immunochemical property of human haptoglobin phenotypes: Determination of plasma haptoglobin using type-matched standards

“…We have recently described simple procedures, in which each Hp phenotype can be isolated using a monoclonal antibody (mAb) affinity column [11,12]. Limited studies [13][14][15] have indicated that the plasma concentration of Hp 1-1 is differentially higher than that of 2-1 and 2-2, but other reports are varied and inconsistent [16][17][18][19]. In the present study, we hypothesized that the inconsistency of reported Hp values could be due to the differences in surface antigenic structures among Hp 1-1, 2-1, and 2-2.…”