Soluble HLA-G is absent from human embryo cultures: a reassessment of sHLA-G detection methods.
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.
Sageshima
Noriko
N
Department of Legal Medicine, Nara Medical University, 840, Shijocho, Kashihara, Nara 634-8521, Japan.
Shobu
Takanori
T
Awai
Keiko
K
Hashimoto
Hiratsugu
H
Yamashita
Masanori
M
Takeda
Nobuyoshi
N
Odawara
Yasushi
Y
Nakanishi
Mari
M
Hatake
Katsuhiko
K
Ishitani
Akiko
A
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
D003470:Culture Media; D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I