title: Seasonal distribution of antiphospholipid antibodies.
abstract: OBJECTIVE
  The purpose of this study was to determine if there was a seasonal variation in antiphospholipid antibody (aPL) titers and whether this variation differed between stroke cases and control subjects.
  
  
  METHODS
  IgG and IgM anticardiolipin and antiphosphatidyl serine antibody titers were obtained on serum samples from 884 stroke patients and 1024 control subjects over a 7-year period. Temporal distributions by month of blood draw were evaluated.
  
  
  RESULTS
  Marked seasonal differences in the proportion of positive titers were found for control subjects, but no seasonal variability among patients was noted. In control subjects, positive titers occurred less frequently in the summer months, mirroring the seasonal trends seen in respiratory track infections and rheumatic fever.
  
  
  CONCLUSIONS
  Our data suggest some aPL antibodies arise from different origins in patients and control subjects. The seasonality observed in the apparently normal population may be related to antibodies of infectious origin and is consistent with the reported lack of association with thrombosis of infection-related antibodies.
authors.affiliation: Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA.
authors.forename: T H
authors.initials: TH
authors.lastname: Luong
authors.forename: J H
authors.initials: JH
authors.lastname: Rand
authors.forename: X X
authors.initials: XX
authors.lastname: Wu
authors.forename: J H
authors.initials: JH
authors.lastname: Godbold
authors.forename: M
authors.initials: M
authors.lastname: Gascon-Lema
authors.forename: S
authors.initials: S
authors.lastname: Tuhrim
mesh_terms: D017677:Age Distribution; D000368:Aged; D017153:Antibodies, Anticardiolipin / Q000097:blood; D017152:Antibodies, Antiphospholipid / Q000097:blood*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010718:Phosphatidylserines / Q000276:immunology; D044469:Racial Groups; D012307:Risk Factors; D012621:Seasons; D012698:Serologic Tests; D017678:Sex Distribution; D020521:Stroke / Q000097:blood / Q000453:epidemiology* / Q000276:immunology*
chemical_list: D017153:Antibodies, Anticardiolipin; D017152:Antibodies, Antiphospholipid; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D010718:Phosphatidylserines