Soluble HLA-G molecules in follicular fluid: a tool for oocyte selection in IVF?

Currently, different approaches are used to select oocytes for in vitro fertilization (IVF) procedures, but they do not assure a significant association with the pregnancy outcome. Since several studies have proposed the expression of HLA-G antigens in early embryos to be a possible marker of elevated implantation rate, we have investigated the presence of soluble HLA-G molecules in 50 follicular fluids (FFs). The results have shown soluble HLA-G antigens (sHLA-G) in 19/50 (38%) FFs. Furthermore, we have related the presence of sHLA-G molecules in FFs to detection of the soluble antigens in culture supernatants of the corresponding fertilized oocyte, evidencing a significant relationship (p=1.3 x 10(-6); Fisher exact p-test). Specific ELISA and Western blot approaches identified both HLA-G5 and soluble HLA-G1 molecules in FFs while immunocytochemical analysis indicated polymorphonuclear-like and granulosa cells as responsible for production of sHLA-G1 and HLA-G5 molecules. In contrast, only sHLA-G1 antigens were detected in culture supernatants of fertilized oocytes. Overall, these results suggest a role for sHLA-G molecules in the ovulatory process and propose the FFs analysis for sHLA-G molecule presence as a useful tool for oocyte selection in IVF.

Evaluation of clinical efficacy of three different insemination techniques in couple infertility. A randomized study.

AIM: The aim of the study was to compare the clinical results and efficiency of three insemination technique: intraperitoneal insemination (IPI), fallopian sperm perfusion (FSP) and intrauterine insemination (IUI). METHODS: The experimental design was a prospective, randomized trial. A total of 101 homologous insemination cycles were performed in 71 consecutive couples with unexplained or male subfertility. Couples were randomized to receive IPI or FSP or IUI by predefined tables of randomization and each couple was submitted to the same insemination technique. The primary outcome of the study was the achievement of clinical pregnancy. RESULTS: The results of the study underlined firstly that basal couple composition was not statistically different between the three groups. Moreover, no significant difference in clinical pregnancy rate was observed, despite a clearly positive trend for FSP, especially for unexplained infertility. CONCLUSIONS: Our results showed that the three techniques of insemination IUI, FSP and IPI have similar efficacy on the achievement of clinical pregnancy in couples affected by longstanding infertility.

Embryonic soluble HLA-G as a marker of developmental potential in embryos.

BACKGROUND: In human reproduction, embryo implantation is complex and poorly understood. At present, no single markers are used in routine treatment to assay biochemical functions of the human embryo. Soluble human leukocyte antigen-G (sHLA-G) could be considered a possible marker of embryo developmental potential. It is localized primarily on the extravillous trophoblast, making this antigen a potential mediator of immune interaction at the maternal-fetal interface during gestation. METHODS: Soluble-HLA-G levels were evaluated by an enzyme-linked immunosorbent assay (ELISA) employing monoclonal antibody MEM-G9. It was evaluated in 318 media of single embryo cultures. We correlated the presence of sHLA-G with embryo morphology and the pregnancy obtained in that treatment cycle. RESULTS: No correlation was found between embryo morphology and sHLA-G levels. Pregnancy was observed only when the medium of at least one transferred embryo contained sHLA-G. In 26 out of 66 patients, none of the obtained embryos showed any detectable sHLA-G molecules and no pregnancy occurred. CONCLUSIONS: From our results, we propose sHLA-G as a potential marker of embryo development: the sHLA-G ELISA can be a useful biochemical assay in addition to embryo morphology in embryo selection for transfer in IVF treatment if there are other embryos with the same morphology.

Effects of low day 3 luteinizing hormone levels on in vitro fertilization treatment outcome.

In a previous study we demonstrated that women with day 3 luteinizing hormone (LH) values < 3 IU/l subjected to controlled ovarian hyperstimulation without pituitary desensitization responded with a lower number of follicles > 15 mm compared to women with a higher basal LH level. The aim of this study was to determine whether in patients with day 3 LH levels < 3 IU/l a further reduction of serum LH concentration by gonadotropin-releasing hormone (GnRH) analog impairs follicular response to follicle stimulating hormone (FSH) and treatment outcome in in vitro fertilization (IVF) cycles. For this purpose we retrospectively studied 249 consecutive women subjected to standard IVF treatment employing pituitary desensitization with buserelin and follicular stimulation with urinary highly purified FSH. The patients were divided into two groups according to their day 3 LH value. The first group (group A) showed day 3 LH levels < 3 IU/l and the second (group B) had day 3 LH levels > 3 IU/l. Group A and B patients did not show statistically significant differences in the ovarian response to FSH, nor in IVF treatment outcome, showing that in FSH treated GnRH analog suppressed cycles, the ovarian responsiveness and IVF outcome do not differ according to basal LH values. However, the high dosage of FSH we employed in group A and B patients could account, at least in part, for this result. Indeed, comparative evaluations with unsuppressed cycles (our previous study) strongly suggest that a reduced ovarian responsiveness to gonadotropins in patients with day 3 LH values < 3 IU/l should be considered in clinical practice.

Non-classic sHLA class I in human oocyte culture medium.

Soluble human leukocyte antigen (sHLA) class I molecules have been described in all human fluids. These molecules play a significant role in immune function. sHLA has been shown to produce tolerance and to induce apoptosis in cytotoxic alloreactive T cells. They are also present in the supernatant of many cultured cells. Similarly, non-classic HLA class I antigens in soluble form are present in human fluids. Among these, HLA-G is the most important because of its location in fetal tissue that suggests maternal immunological tolerance of the fetal semiallograft. In our present study we show that using two monoclonal antibodies, w6/32 and TP25.99, in the enzyme-linked immunosorbent assay allows the detection of non-classic sHLA class I molecules in the medium from human embryo cultures. The sample were collected from oocytes cultures. Oocyte donors were 11 women attending the in vitro fertilization program. The results showed a significant association (chi2 = 9.66, p = 0.002) between sHLA antigens and the oocyte cleavage rate measured 48 h after fertilization.

The ovary is not a major source of placental protein 14 (glycodelin).

Placental protein 14 (PP14) is the major glycoprotein synthesized by late secretory endometrium and gestational decidua. The control mechanisms of PP14 production are uncertain but might include progesterone or an ovarian factor. It has been suggested that PP14 might be produced by the ovary itself. The aim of the present study was to evaluate if the ovary is a major source of PP14. We measured PP14 and also insulin-like growth factor binding protein-1 (IGFBP-1), another protein produced in large amounts by the secretory endometrium though not specific to that tissue. The samples included sera from the ovarian vein in one subject, sera of three women affected with Rokitansky syndrome (absent uterus) and follicular fluid samples collected during oocyte recovery in 46 in-vitro fertilization patients. PP14 was undetectable in the sample collected from the ovarian vein at the mid-luteal phase and was absent or at very low concentrations in most of the follicular fluid samples. Furthermore, the predominantly uterine origin was confirmed by the inability to detect any PP14 in sera throughout the menstrual cycle from patients with congenital absence of the uterus (Rokitansky syndrome). In conclusion this study shows that the ovary is not a major source of PP14.

A sperm survival test and in-vitro fertilization outcome in the presence of male factor infertility.

Several tests based on semen variables have been proposed to predict the fertilization rate in the presence of male factor infertility, but their significance remains unclear. We investigated the utility of a screening test based on sperm survival (SST) to predict the outcome of in-vitro fertilization (IVF) cycles in the presence of male factor infertility. The SST was considered normal when the percentage of motile spermatozoa 24 h after oocyte insemination was > or =50%. The sperm survival test yielded abnormal results in <90% of cycles which were unsuccessful. The sensitivity of the SST was 87% and specificity 65% with a positive predictive value of 90% in the male factor group. We believe that the SST may be a useful predictor of the IVF cycle outcome and we propose its introduction into the routine preliminary evaluation of semen samples in cases of male factor infertility.

Two functional assays of sperm responsiveness to progesterone and their predictive values in in-vitro fertilization.

We have recently reported, in a small cohort of subjects, that acrosome reaction (AR) and intracellular free calcium ([Ca2+]i) increase in response to progesterone were significantly correlated with in-vitro fertilization (IVF) rate. In the present study we extended these results to 90 subjects undergoing IVF. We confirm that both parameters were highly significantly correlated with the fertilization rate (P < 0.001). In particular, significantly lower responses to progesterone were detected in subjects with a fertilization rate < 50%, further enlightening the functional significance of sperm responsiveness to progesterone with respect to the process of fertilization. Moreover, we report here that both tests are highly discriminant of fertilization success, with positive predictive values > 90% for [Ca2+]i values which increase by > 1.2-fold and AR inducibility > 7% (cut-off values). Conversely, AR following challenge with the calcium ionophore A23187 was less significantly correlated with the percentage fertilization rate (P < 0.05), and showed lower predictive values than response to progesterone. All these tests ([Ca2+]i increase in response to progesterone, AR in response to progesterone and to A23187) appear highly sensitive and moderately specific. The positive predictive value may rise to > 95% when the combination of two tests ([Ca2+]i and inducibility of AR in response to progesterone) is considered. No correlation with fertilization rate has been found for spontaneous AR or basal [Ca2+]i. In conclusion, we propose that assessment of human sperm responsiveness to progesterone may be clinically useful in predicting fertilizing ability in vitro.

In-vivo studies on ovarian insulin-like growth factor I concentrations in human preovulatory follicles and human ovarian circulation.

In some recent hypotheses, the ovary has been indicated as a source of insulin-like growth factor (IGF)-I, with synthesis regulated from local steroidal and non-steroidal substances. We measured IGF-I concentrations in both serum and follicular fluid of women undergoing in-vitro fertilization (IVF) and embryo transfer, in both induced and spontaneous cycles. It was found that serum and follicular IGF-I concentrations were correlated with follicular morphology, oocyte maturity, steroid concentrations and clinical characteristics of IVF cycles. In addition, we measured IGF-I concentrations in both peripheral and ovarian circulation to gain further detailed information on the contribution of the ovary to IGF-I production. The results of our study support the hypothesis that follicular IGF-I is probably derived by diffusion from peripheral circulation and that local production appears unlikely.

Intracellular calcium increase and acrosome reaction in response to progesterone in human spermatozoa are correlated with in-vitro fertilization.

In this study we have investigated responsiveness to progesterone in spermatozoa from a group of unselected male partners of couples undergoing in-vitro fertilization (IVF). We evaluated progesterone-stimulated intracellular Ca2+ ([Ca2+]i) and percentage increase in acrosome reaction in the same sperm sample used for oocyte inseminations. [Ca2+]i was measured with a fluorimetric method, while the acrosome reaction was assessed using a fluorescent probe (fluorescein isothiocyanate-labelled peanut lectin). The average percentage [Ca2+]i as well as the rate of increase in the frequency of acrosome reaction following progesterone challenge were significantly lower (P < 0.005) in the group of patients with a fertilization rate < 50%. In addition, significant correlations between the fertilization rate and the progesterone-stimulated [Ca2+]i and acrosome reaction increases (r = 0.78 and r = 0.79 respectively) were observed. Furthermore, in cases of fertilization failure, no increase of [Ca2+]i or acrosome reaction was observed in response to progesterone with the exception of one case. Our results indicate that [Ca2+]i and acrosome reaction increases in response to progesterone can be of value in the prediction of sperm fertilizing ability. As the two parameters were significantly correlated to each other (r = 0.86), the two assays have similar IVF predictive value and might be used interchangeably as a diagnostic tool in the assignment of male patients to the different kinds of assisted fertilization techniques.

Estrone 3-glucuronide chemiluminescence immunoassay (LIA) and 17beta estradiol radioimmunoassay (RIA) in the monitoring of superovulation for in vitro fertilization (IVF): correlation with follicular parameters and oocyte maturity.

Many works in the literature of the last years had reported that urinary approach to superovulation study is a suitable method to evaluate ovarian response to pharmacological stimulation. Before applying urinary determination of hormonal levels with a chemiluminescence immuno assay (LIA) method in early morning urine (EMU) samples, we had studied the correlation of RIA-LIA procedures with reference to follicular volumes at hCG day and to recovered oocyte maturity; in fact follicular growth and oocyte morphological features are the main parameters to evaluate a successful induced cycle. In our department the IVF cycles are daily monitored with RIA seric E2 and LIA E1-3G determination, besides ultrasound examination of follicular growth. We have studied E2 and E1-3G levels on the hCG administration day and their correlation with follicular areas and volumes; moreover, we have evaluated hormonal values on oocyte pick-up day with reference to recovered oocyte number and maturity. We have assumed as good timing for oocyte pick-up when more than 50% of recovered oocytes were of good quality (maturity score 4). We have observed that the highest pre ovulatory E1-3G value is consistent with the best timing for oocyte pick-up; it's possible to obtain a conversion coefficient follicular volumes and urinary E1-3G excretion. We have not found significant differences between plasmatic and urinary estrogenic parameters. It is important to remember the advantages connected by a not isotopic and not invasive method. The absence of discomfort for the patients may be a decisive factor to choose the monitoring method and LIA procedure may represent a valid alternative to RIA.