IgG antiphospholipid antibodies linked to heart attack
CHICAGO — The presence of IgG antiphospholipid antibodies is strongly and independently associated with myocardial infarction, according to data presented by Elisabet Svenungsson, MD, of Karolinska University Hospital, in Stockholm.
“These antibodies are associated with thrombosis in all types of vessels, in arterial circulation, the small vessels and also the venous vessels,” Svenungsson said, addressing attendees at the ACR/ARHP 2018 Annual Meeting. “Deep venous thrombosis is probably the most studied complication of these antibodies, but also stroke and, in our study, myocardial infarction. The novelty for our study is that we have turned the perspective around to look at the impact of these antibodies on the general population.”
To analyze the role of antiphospholipid autoantibodies in patients with myocardial infarction (MI), Svenungsson and colleagues examined 805 participants aged younger than 75 years who were evaluated 6 to 10 weeks following a first-time MI. These patients were matched to 805 control individuals from the general population, who had not experienced MI, based on age, sex and area.
The researchers used paired statistical analysis to find associations between antiphospholipid antibody positivity — including anti-cardiolipin, anti-2glycoprotein-I (anti-2-GPI), IgG, IgM and IgA — and MI. The researchers also tested patients with antibody-positive MI and six previously-diagnosed individuals with antiphospholipid syndrome on a peptide ELISA for reactivity to specific domains of the 2GPI protein.
According to Svenungsson, 10.9% of patients who experienced MI were positive for IgG anti-cardiolipin, compared to 0.9% among the control group. In addition, 10.4% of patients with MI were positive for anti-2GPI, compared to 0.9% of controls. The researchers also noted that many of the participants with MI demonstrated high IgG titers. IgG positivity for anti-CL and anti-2-GPI was also highly correlated; combining these antibodies to constitute antiphospholipid-autoantibody IgG positivity, this status remained associated with MI after adjusting for traditional cardiovascular risk factors. These factors included smoking, hypertension, diabetes and BMI.
“If these results are confirmed, it could change the handling of myocardial infarction patients,” Svenungsson said. “If 10% of patients with myocardial infarction are positive for the antibodies, then I think we should screen for this.” – by Jason Laday
Svenungsson E. “Abstract 855. Presented at ACR/ARHP Annual Meeting, Oct. 20-24, 2018; Chicago.
Disclosure: Svenungsson reports no relevant financial disclosures.