Low levels of immunoglobulin-M (IgM) autoantibodies against lipid phosphorylcholine (PC) add prognostic information in acute coronary syndromes (ACS).

The IgM autoantibodies can be easily measured by immunoassay and can be correlated with other known biomarkers in cases of atherosclerosis and other inflammatory diseases.

A team of scientists from the Karolinska Institutet (Stockholm, Sweden), collected and analyzed blood samples from 1,185 patients within 24 hours of admission between September 1995 and March 2001. Serum IgM anti-PC titers were measured by an enzyme-linked immunosorbent assay (ELISA) using a prototype of the Athera CVDefine kit. The assay is based on PCs covalently linked to bovine serum albumin coated onto 96-well microtiter plates. The detection limit was 0.5 U/L and coefficients of variation were less than 7%.

The results of the analysis showed that patients with low levels of anti-PC in connection with ACS and refractory, unstable angina run a greater risk of complications and premature death. The risk of death was more than double in coronary patients with low levels of anti-PC, who also had a significantly higher risk of additional heart attacks or other complications. The results also demonstrated for the first time that low anti-PC titers in ACS are associated with a considerably increased risk of a new acute cardiovascular event during several years, as well as increased mortality risk within, at least, the first 18 months after the primary ACS event. Low anti-PC titers may therefore represent a novel paradigm for reporting reduced atheroprotection in coronary vascular disease (CVD). The Athera CVDefine ELISA kit used in the study is a product of Athera Biotechnologies AB (Stockholm, Sweden).

Johan Frostegård, PhD, lead author and a professor at the Karolinska Institutet said, "The immunological treatment of cardiovascular diseases is clearly a Swedish specialty. Other Swedish researchers maintain that it's apolipoprotein B, an important constituent of LDL, that we should be vaccinating against, but the two aren't mutually exclusive and a combination is conceivable and something that we're now also testing." His team has spent many years developing immunological treatments for atherosclerotic plaque based on exploiting anti-PC to target phosphorylcholine. The study was published online on February 3, 2012, in the International Journal of Cardiology.

Related Links:
Karolinska Institutet
Athera Biotechnologies AB