title: Association of Epstein-Barr virus antibody titers with a human IL-10 promoter polymorphism in Japanese women.
abstract: BACKGROUND
  Multiple sclerosis (MS) risk, over 10-fold higher in Western than in Asian countries, is associated with elevated IgG antibody titers against Epstein-Barr viral capcid antigen (anti-EBVCA IgG titers). Given the 84% homology of the open reading frame BCRF1 of Epstein-Barr virus (EBV) to human interleukin 10 (hIL-10) and the remarkable Caucasian-vs.-Asian population differences in hIL-10 gene promoter polymorphisms, this strong association of MS risk with anti-EB-VCA IgG titers may be explained by the genetic variations in the hIL-10 gene.
  
  
  METHODS
  We evaluated anti-EB-VCA IgG titers in association with a single nucleotide polymorphism (SNP) in the promoter of hIL-10 at position -819 (hIL-10 T-819C) in a cross-sectional survey of 241 Japanese. Anti-EB-VCA IgG titer and its elevation (> or = 1:160) were evaluated, stratified by sex and hIL-10 T-819C genotype.
  
  
  RESULTS
  The cytosine-allele frequencies at hIL-10 T-819C were 32.9% in women and 30.9% in men. These are consistent with the published reports of Japanese and Chinese, but substantially lower than those of Caucasians (> 70%). In women, the proportion with elevated anti-EB-VCA IgG titers (> or = 1:160) increased appreciably from 53.7% in the T/T genotype group to 66.7% in the T/C group and to 83.3% in the C/C group (P-trend = 0.037). The titers did not differ by the hIL-10 T-819C genotype in men.
  
  
  CONCLUSIONS
  Anti-EB-VCA IgG titers may increase with the number of cytosine alleles at hIL-10 T-819C in women. This observed gender specific association in Japanese warrants further investigation, especially in Western populations with high MS risk.
authors.affiliation: Department of Public Health Sciences, School of Public Health, University of Alberta, Edmonton, AB, Canada. yyasui@ualberta.ca
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yasui
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hamajima
authors.forename: Tsuneya
authors.initials: T
authors.lastname: Nakamura
authors.forename: Noha Sharaf
authors.initials: NS
authors.lastname: El-Din
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tajima
authors.forename: John D
authors.initials: JD
authors.lastname: Potter