Low levels of IgM antibodies against phosphorylcholine—A potential risk marker for ischemic stroke in men

BackgroundNatural antibodies specific for phosphorylcholine (anti-PC) have been implicated as protective factors in atherosclerosis. We herein determined the relationship between IgM anti-PC and incidence of cardiovascular disease (CVD).MethodsWe studied 349 incident cases (200 men) of first events of CVD (coronary heart disease (CHD; n = 203 or ischemic stroke; n = 146) and 693 age- and sex-matched controls identified through 12 years of follow-up (1991–2003) of subjects from the cardiovascular cohort within the Malmö Diet and Cancer Study. Relative risks (RR) of CVD with 95% confidence intervals (CI) of incident CVD with adjustments for age, smoking, total cholesterol and blood pressure were determined. Anti-PC-levels were measured using ELISA (Athera CVDefine™).ResultsAs determined using Athera CVDefine™, significant associations were attained with values of anti-PC below 17 U/ml (corresponding to the lowest 9th percentile), which remained after taking confounders into account (RR: 1.79, 95% CI: 1.09–2.94, p = 0.021). If men were studied separately, significance was evident at values below 17 U/ml (RR: 2.01, 95% CI: 1.11–3.67, p = 0.022), which was not the case among women. Furthermore, values below 17 U/ml were also associated with ischemic stroke (RR = 3.67, 95% CI: 1.34–10.1, p = 0.01), but not with CHD.ConclusionLow IgM anti-PC could be a novel risk marker for development of ischemic stroke in men. Further studies are needed to establish gender and subgroup differences.