Autoantibodies against the endothelial receptor of protein C are associated with acute myocardial infarction in young women.
BACKGROUND
Acute myocardial infarction (AMI) is rare among young women. The search for unknown risk factors is warranted. Endothelial protein C receptor (EPCR) is largely present at the endothelial surface of large arteries. No studies about association of anti-EPCR autoantibodies (anti-EPCR) with AMI are available.


METHODS
Plasma IgA, IgM and IgG anti-EPCR levels were measured by enzyme-linked immunosorbent assay in 165 women younger than 45 years who survived a first AMI and 165 healthy women, matched by age and geographical origin.


RESULTS
Using the 90th percentile of IgA anti-EPCR in the control group, IgA anti-EPCR were independently associated with AMI after adjustment for cardiovascular risk factors (OR 5.1; 95% CI 1.7-15.6; P = 0.004). The risk apparently conferred by IgA anti-EPCR increased dose-dependently (P for trend =0.0002). IgM anti-EPCR were less consistently associated with AMI: a significant increase in the risk was found when women above the 90th percentile were compared with those in the lowest quartile (OR 3.6; 95% CI 1.2-11.5; P = 0.03). IgG anti-EPCR were similar in patients and controls. A total of 145 patients underwent coronary arteriography. IgA or IgM anti-EPCR were not different among patients with different degrees of atherosclerotic lesion (anova, P = 0.77 and 0.24, respectively).


CONCLUSIONS
High levels of IgA and, to a lesser extent, IgM anti-EPCR, are associated with AMI in young women.
Haematology Department and the Division of Cardiovascular Pathophysiology, Laboratory of Thrombosis and Haemostasis, Clínica Universitaria/School of Medicine, Applied Medical Research Centre, Pamplona, Spain. rmontes@unav.es
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Montes
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Alonso
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Mannucci
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Hermida
D000328:Adult; D001323:Autoantibodies / Q000737:chemistry*; D001779:Blood Coagulation Factors / Q000276:immunology*; D016022:Case-Control Studies; D023921:Coronary Stenosis / Q000473:pathology; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000737:chemistry; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000276:immunology*; D016017:Odds Ratio; D011956:Receptors, Cell Surface / Q000276:immunology*; D012307:Risk Factors
D001323:Autoantibodies; D001779:Blood Coagulation Factors; D000939:Epitopes; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011956:Receptors, Cell Surface; C091963:activated protein C receptor