title: Soluble HLA-G is absent from human embryo cultures: a reassessment of sHLA-G detection methods.
abstract: In recent years, the number of patients receiving in vitro fertilization (IVF) has been increasing, though the rate of successful implantations has remained at 10-20%. A major goal of this procedure is to afford the ability to select embryos with the most potential for implantation and development. Previous studies claimed to have detected soluble HLA-G (sHLA-G) protein in culture supernatant from 2 to 3-day embryos using ELISA methods, and concluded that sHLA-G protein levels were associated with successful implantation. This result, if substantiated could provide an important tool for IVF. In this study, we have re-examined these experiments by attempting to detect sHLA-G in the medium from 2 to 3-day embryos (84 samples) and 4 to 6-day embryos (25 samples) in which a part of blastocyst has started to differentiate into trophoblasts. Using a highly specific and sensitive ELISA, no sHLA-G protein was detectable in any sample, despite the fact that 27 of the 109 samples were from successfully implanted embryos. These results indicate that 2-6-day embryos do not secrete sHLA-G detectable by ELISA, and therefore that sHLA-G in culture medium is not a useful for successful implantation at this stage of development.
authors.affiliation: Department of Legal Medicine, Nara Medical University, 840, Shijocho, Kashihara, Nara 634-8521, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Sageshima
authors.forename: Takanori
authors.initials: T
authors.lastname: Shobu
authors.forename: Keiko
authors.initials: K
authors.lastname: Awai
authors.forename: Hiratsugu
authors.initials: H
authors.lastname: Hashimoto
authors.forename: Masanori
authors.initials: M
authors.lastname: Yamashita
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Takeda
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Odawara
authors.forename: Mari
authors.initials: M
authors.lastname: Nakanishi
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Hatake
authors.forename: Akiko
authors.initials: A
authors.lastname: Ishitani
mesh_terms: D003470:Culture Media / Q000032:analysis; D046149:Embryo Culture Techniques; D010064:Embryo Implantation; D004622:Embryo, Mammalian / Q000276:immunology*; D047108:Embryonic Development; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005307:Fertilization in Vitro; D006680:HLA Antigens / Q000032:analysis* / Q000302:isolation & purification; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000032:analysis* / Q000302:isolation & purification; D006801:Humans; D011247:Pregnancy; D012680:Sensitivity and Specificity
chemical_list: D003470:Culture Media; D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I