title: Analysis of HLA-G polymorphisms in couples with implantation failure.
abstract: OBJECTIVE
  HLA-G expression is related as an immune modulator of fetal-maternal tolerance, and its levels was correlated with pregnancy outcome. In a case-control study, we investigate the association between the genetic variability of the HLA-G gene and serum levels of soluble HLA-G in cases of embryo implantation failure.
  
  
  METHODS
  Forty couples with at least two unsuccessful fresh embryo transfers (implantation failure; IF) and 83 fertile couples with at least two successful pregnancies was genotyped by sequencing-based typing. HLA-G alleles were defined by nucleotide sequence variations at exon 2, 3, and 4, and the quantification of soluble HLA-G (sHLA-G) was performed by ELISA.
  
  
  RESULTS
  There was a significant difference between the HLA-G allelic distributions between IF couples and the control couples. The HLA-G*01:03:01 allele was increased in the IF couples. There were no significant differences in the serum levels of sHLA-G in the IF and control groups.
  
  
  CONCLUSIONS
  The results suggest that the distribution of HLA-G products may play a significant role in the modulation of maternal-fetal immune response.
authors.affiliation: Laboratory of Immunogenetics and Histocompatibility, Genetics Department, Universidade Federal do Paraná, Curitiba, Brazil.
authors.forename: Fabiola da Silva
authors.initials: Fda S
authors.lastname: Nardi
authors.forename: Renata
authors.initials: R
authors.lastname: Slowik
authors.forename: Pryscilla Fanini
authors.initials: PF
authors.lastname: Wowk
authors.forename: José Samuel
authors.initials: JS
authors.lastname: da Silva
authors.forename: Geórgia Fernanda
authors.initials: GF
authors.lastname: Gelmini
authors.forename: Tatiana Ferreira
authors.initials: TF
authors.lastname: Michelon
authors.forename: Jorge
authors.initials: J
authors.lastname: Neumann
authors.forename: Maria da Graça
authors.initials: Mda G
authors.lastname: Bicalho
mesh_terms: D000026:Abortion, Habitual / Q000235:genetics; D000022:Abortion, Spontaneous / Q000235:genetics; D000328:Adult; D000483:Alleles; D016022:Case-Control Studies; D010064:Embryo Implantation / Q000235:genetics* / Q000276:immunology; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D059951:HLA-G Antigens / Q000097:blood* / Q000235:genetics*; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy
chemical_list: D059951:HLA-G Antigens