title: Platelet count and interleukin 6 gene polymorphism in healthy subjects.
abstract: BACKGROUND
  Interleukin 6 (IL-6) is thought to play important roles in the development of reactive thrombocytosis caused by inflammation by its stimulatory effect on megakaryocytopoiesis. A G/C polymorphism of the IL-6 gene at position -174 has been found to be associated to different transcription rates. Specifically, subjects with the CC genotype showed lower plasma IL-6 levels compared with GC or GG subjects. Given this difference in transcription rates of IL-6 we speculated on different platelet count according to this IL-6 polymorphism.
  
  
  METHODS
  The G/C polymorphism of the IL-6 gene at position -174, serum IL-6 concentration and platelet count were prospectively analyzed in 59 (25 women) consecutive healthy subjects.
  
  
  RESULTS
  Subjects who were homozygotes for the C allele at position -174 of the IL-6 gene (Sfa NI genotype) showed significantly lower platelet count than carriers of the G allele, despite similar age, sex, body mass index and proportion of smokers (205400 +/- 44088 vs 239818 +/- 60194, p = 0.047). This was in parallel to differences in peripheral white blood cell count (5807 +/- 1671 vs 6867 +/- 1192 x 10(9)/ml, p = 0.01).
  
  
  CONCLUSIONS
  This is the first description, to our knowledge, of a genetical influence on basal platelet counts, which appears to be partially dependent on a polymorphism of the IL-6 gene, even in the absence of inflammation.
authors.affiliation: Unitat de Diabetologia, Endocrinologia i Nutricio, University Hospital of Girona Dr Josep Trueta, Girona, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Fernandez-Real
authors.forename: J
authors.initials: J
authors.lastname: Vendrell
authors.forename: C
authors.initials: C
authors.lastname: Richart
authors.forename: C
authors.initials: C
authors.lastname: Gutierrez
authors.forename: W
authors.initials: W
authors.lastname: Ricart