title: Low levels of IgM antibodies against phosphorylcholine-A potential risk marker for ischemic stroke in men.
abstract: BACKGROUND
  Natural 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).
  
  
  METHODS
  We 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).
  
  
  RESULTS
  As determined using Athera CVDefine, significant associations were attained with values of anti-PC below 17U/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 17U/ml (RR: 2.01, 95% CI: 1.11-3.67, p=0.022), which was not the case among women. Furthermore, values below 17U/ml were also associated with ischemic stroke (RR=3.67, 95% CI: 1.34-10.1, p=0.01), but not with CHD.
  
  
  CONCLUSIONS
  Low 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.
authors.affiliation: Department of Medicine, Karolinska University Hospital Huddinge, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Beatrice G
authors.initials: BG
authors.lastname: Sjöberg
authors.forename: Jun
authors.initials: J
authors.lastname: Su
authors.forename: Ingrid
authors.initials: I
authors.lastname: Dahlbom
authors.forename: Hans
authors.initials: H
authors.lastname: Grönlund
authors.forename: Max
authors.initials: M
authors.lastname: Wikström
authors.forename: Bo
authors.initials: B
authors.lastname: Hedblad
authors.forename: Göran
authors.initials: G
authors.lastname: Berglund
authors.forename: Ulf
authors.initials: U
authors.lastname: de Faire
authors.forename: Johan
authors.initials: J
authors.lastname: Frostegård
mesh_terms: D000368:Aged; D050197:Atherosclerosis / Q000097:blood* / Q000175:diagnosis*; D002545:Brain Ischemia / Q000097:blood* / Q000175:diagnosis*; D002318:Cardiovascular Diseases / Q000097:blood / Q000175:diagnosis; D002784:Cholesterol / Q000378:metabolism; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010767:Phosphorylcholine / Q000737:chemistry*; D012306:Risk; D012307:Risk Factors; D012737:Sex Factors; D020521:Stroke / Q000097:blood* / Q000175:diagnosis*
chemical_list: D007075:Immunoglobulin M; D010767:Phosphorylcholine; D002784:Cholesterol