OBJECTIVE: To investigate further the association between human leukocyte antigen G (HLA-G) expression in human embryos and other factors known to influence IVF pregnancy outcome. SETTING: A university-based tertiary referral center (The Toronto Hospital). INTERVENTIONS: Nontransferred embryos at the two- to four-cell stage were obtained from patients undergoing IVF and were cultured in Ham's F-10 medium supplemented with 10% human sera or cocultured with ovarian cancer cells in the same medium. Embryos that reached blastocyst stage (n = 148) were analyzed by reverse transcriptase-polymerase chain reaction for HLA-G and beta 2 microglobulin (beta 2m) expression. Statistical analysis was performed to identify possible factors associated with variability of expression. RESULTS: Approximately 40% of studied blastocysts had detectable expression of both HLA-G and beta 2m messenger RNA. In 46% of blastocysts, beta 2m alone was observed. Interestingly, sibling embryos from patients that became pregnant were significantly more likely to express HLA-G than embryos from patients that did not conceive as a result of their IVF cycles. No association was found between HLA-G expression and culture conditions, patients age, or infertility diagnosis. CONCLUSION: The population of embryos obtained through IVF is heterogeneous in expression of HLA-G and beta 2m, which may reflect overall health of the embryos. Blastocysts showing positive HLA-G expression may have increased viability and implantation potential, although the underlying mechanisms remain to be elucidated.
OBJECTIVE: To investigate further the association between human leukocyte antigen G (HLA-G) expression in human embryos and other factors known to influence IVF pregnancy outcome. SETTING: A university-based tertiary referral center (The Toronto Hospital). INTERVENTIONS: Nontransferred embryos at the two- to four-cell stage were obtained from patients undergoing IVF and were cultured in Ham's F-10 medium supplemented with 10% human sera or cocultured with ovarian cancer cells in the same medium. Embryos that reached blastocyst stage (n = 148) were analyzed by reverse transcriptase-polymerase chain reaction for HLA-G and beta 2 microglobulin (beta 2m) expression. Statistical analysis was performed to identify possible factors associated with variability of expression. RESULTS: Approximately 40% of studied blastocysts had detectable expression of both HLA-G and beta 2m messenger RNA. In 46% of blastocysts, beta 2m alone was observed. Interestingly, sibling embryos from patients that became pregnant were significantly more likely to express HLA-G than embryos from patients that did not conceive as a result of their IVF cycles. No association was found between HLA-G expression and culture conditions, patients age, or infertility diagnosis. CONCLUSION: The population of embryos obtained through IVF is heterogeneous in expression of HLA-G and beta 2m, which may reflect overall health of the embryos. Blastocysts showing positive HLA-G expression may have increased viability and implantation potential, although the underlying mechanisms remain to be elucidated.
Authors: Roberta Rizzo; Martine Vercammen; Hilde van de Velde; Peter A Horn; Vera Rebmann Journal: Cell Mol Life Sci Date: 2010-11-16 Impact factor: 9.261