Katrin van der Ven

Gonadal Function and Fertility in Survivors After Hodgkin Lymphoma Treatment Within the German Hodgkin Study Group HD13 to HD15 Trials

PURPOSE To optimize fertility advice in patients with Hodgkin lymphoma (HL) before therapy and during survivorship, information on the impact of chemotherapy is needed. Therefore, we analyzed gonadal functions in survivors of HL. PATIENTS AND METHODS Women younger than age 40 and men younger than 50 years at diagnosis in ongoing remission at least 1 year after therapy within the German Hodgkin Study Group HD13 to HD15 trials for early- and advanced-stage HL were included. Hormone parameters, menstrual cycle, symptoms of hypogonadism, and offspring were evaluated. RESULTS A total of 1,323 (55%) of 2,412 contacted female and male survivors were evaluable for the current analysis (mean follow-up, 46 and 48 months, respectively). Follicle-stimulating hormone, anti-Müllerian hormone, and inhibin B levels correlated significantly with therapy intensity (P < .001). Low birth rates were observed in survivors after advanced-stage treatment within the observation time (women, 6.5%; men, 3.3%). Regular menstrual cycle was reported by more than 90% of female survivors of early-stage HL (recovery time mostly ≤ 12 months). After six to eight cycles of bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone, menstrual activity was strongly related to age (< v ≥ 30 years: 82% v 45%, respectively; P < .001; prolonged recovery time). Thirty-four percent of women age ≥ 30 years suffered severe menopausal symptoms (three- to four-fold more frequently than expected). In contrast, male survivors had mean levels of testosterone within the normal range and reported no increased symptoms of hypogonadism. CONCLUSION The present analysis in a large group of survivors of HL provides well-grounded information on gonadal toxicity of currently used treatment regimens and allows risk-adapted fertility preservation and comprehensive support during therapy and follow-up.

Population genetic studies of HLA-G: allele frequencies and linkage disequilibrium with HLA-A

HLA-G is a class I gene that is expressed in the extravillous cytotrophoblast. Although the function of this gene is still unknown, its expression at the maternal-fetal interface suggests that HLA-G may play a key role in the induction of tolerance during pregnancy. Preliminary to our studies of the effects of HLA-G polymorphisms on pregnancy outcome, we have defined HLA-G alleles in the Hutterites. We report here the presence of nine HLA-G alleles that differ with respect to nucleotide sequences, including four groups of alleles that differ with respect to amino acid sequences, and striking linkage disequilibrium between HLA-G and HLA-A alleles. The levels and sites of polymorphism in HLA-G suggest that this gene had a unique evolutionary history and may perform nonclassical functions at the maternal-fetal interface.

Effect of mono-(2-ethylhexyl) phthalate on steroid production of human granulosa cells.

The phthalate ester mono-(2-ethylhexyl) phthalate (MEHP) is the active metabolite of di-(2-ethylhexyl) phthalate, a high-production-volume chemical used as a plasticizer and solvent in numerous consumer products. MEHP has been demonstrated to be a reproductive toxicant in rodents decreasing estradiol and progesterone production in preovulatory granulosa cells. In the present study, we examined the effect of MEHP on steroid production of human granulosa-lutein (GL) cells. Human GL cells collected from women undergoing in vitro fertilization were cultured in medium containing FSH, hCG and 8-Br-cAMP, respectively, together with various concentrations of MEHP (0-500 micromol L(-1)). After incubation for 48 h estradiol and progesterone were assayed in the spent culture medium. Furthermore, aromatase activity and mRNA levels of GL cells were determined. Basal as well as FSH-, hCG- and 8-Br-cAMP-stimulated estradiol production of GL cells was suppressed by MEHP in a dose-dependent manner (IC(50)=105 micromol L(-1), 138 micromol L(-1), 49 micromol L(-1) and 78 micromol L(-1)). Furthermore aromatase activity and mRNA levels were reduced in GL cells cultured with MEHP. In contrast, MEHP did not alter the production of progesterone up to a concentration of 167 micromol L(-1). The present data indicate that MEHP is a specific inhibitor of estradiol production in human GL cells with a post-cAMP site of action. The inhibition of estradiol production obviously results from a reduction of aromatase activity on the transcript level. As the in vitro effective doses of MEHP are within the range of real environmental exposure levels an inhibitory effect on estrogen production in vivo seems to be possible.

The benefit of artificial oocyte activation is dependent on the fertilization rate in a previous treatment cycle

Following intracytoplasmic sperm injection (ICSI), some patients present low or zero fertilization rates. Artificial oocyte activation has been proposed as a suitable means to overcome this problem. This study applied artificial oocyte activation in patient cohorts with a history of no fertilization (0%, group 1), fertilization between 1 and 29% (group 2) or fertilization between 30 and 50% (group 3) in initial ICSI cycles. In the following treatment cycles, oocytes were activated after ICSI using calcium ionophore. Fertilization, pregnancy and take-home baby rates were compared with the previous cycle without activation. In group 1, fertilization rate was 41.6%, embryos for transfer were available in 82.1% of cycles, giving a clinical pregnancy rate of 18.8% and take-home baby rate of 12.8%. In group 2, despite a lower transfer rate (87.9% versus 100%, P<0.05), there were higher fertilization and clinical pregnancy rates (44.4% versus 19.3% and 31.4% versus 12.8%, respectively, P<0.05) and take-home baby rate was 24.1% versus 12.8%. In group 3, fertilization rates differed (56.1% versus 36.8%; P<0.001) but all other parameters were similar. Artificial oocyte activation has great potential especially in patients showing compromised fertilization rates below 30% after standard ICSI. Following intracytoplasmic sperm injection (ICSI), some patients present very low or even zero fertilization rates after ICSI. Artificial oocyte activation has been proposed as a suitable means to overcome this problem. We applied artificial oocyte activation in patients which presented a history either no fertilization, fertilization between 0 and 30% or fertilization between 30 and 50% in initial ICSI cycles. In the following treatment cycles, oocytes were activated after ICSI using a calcium ionophore. Fertilization, pregnancy and take-home baby rates were compared to the previous cycle without activation. For the groups with previously 0% or 1-29% fertilization, we noted higher fertilization rates and clinical pregnancy rates per embryo transfer. For the group with moderate fertilization, only fertilization rates differed but all other parameters were not significantly different. From these data we conclude that artificial oocyte activation has a great potential especially in patients which show a compromised fertilization rate below 30% in a standard ICSI cycle.

Biomarkers of human oocyte developmental competence expressed in cumulus cells before ICSI: a preliminary study

PurposeTo identify reliable genomic biomarkers expressed in cumulus cells that accurately and non-invasively predict the oocyte developmental competence and reinforce the already used morphological criteria.MethodsEight consenting patients were selected for ovarian stimulation and ICSI procedures. Cumulus-oocyte complexes were transvaginally punctured and individually selected based on both good morphological criteria and high zona pellucida birefringence. Following ICSI, two 3-day embryos per patient were transferred. Pregnancy outcome was recorded and proven implantation was thereafter confirmed. Differential gene expression was assessed using two microarray platforms. Further real-time PCR validation, Ingenuity pathways analysis and intra-patient analysis were performed on 17 selected candidates.ResultsSeven genes were differentially (p ≤ 0.05) associated to successful pregnancy and implantation. These biomarkers could be used to predict the oocyte developmental competence.ConclusionsThese genomic markers are a powerful reinforcement of morphological approaches of oocyte selection. Their large-scale validation could increase pregnancy outcome and single embryo transfer efficiency.

Effective method for in-vitro culture of cryopreserved human ovarian tissue.

It is widely accepted that it is possible to successfully cryopreserve human ovarian tissue by direct plunging into liquid nitrogen using permeable cryoprotectants only, without disaccharides. This study aimed to search for and test a new method for in-vitro culture of vitrified tissue. Ovarian biopsies were obtained during operative laparoscopy. Pieces of ovarian tissue were vitrified and warmed. After warming, tissue pieces were randomly distributed into three groups for further culture: in 2 ml of culture medium which was regularly renewed (group 1), in 30 ml of culture medium without agitation (group 2) and in 30 ml of culture medium with agitation (group 3). During the 2-week and 6-week culture, the growth of follicles within the vitrified-warmed ovarian tissue pieces was investigated. After 2 weeks of culture, mean numbers of non-degenerated follicles per mm(2) of tissue were 1.5, 1.7 and 4.5 for groups 1, 2 and 3 respectively (groups 1 and 2 versus group 3, P < 0.05). Agitation during culture of ovarian tissue is beneficial, and can be used as a prognostic tool for future warming and autotransplantation of ovarian tissue.

Effects of histamine and diamine oxidase activities on pregnancy: a critical review

BACKGROUND Histamine has been assumed to contribute to embryo-uterine interactions due to its vasoactive, differentiation and growth-promoting properties. However, its exact functions in pregnancy are unclear. The histamine-degrading enzyme diamine oxidase (DAO) is produced in high amounts by the placenta and has been supposed to act as a metabolic barrier to prevent excessive entry of bioactive histamine from the placenta into the maternal or fetal circulation. METHODS The literature available on PubMed published in English between 1910 and 2008 has been searched using the isolated and combined key words histamine, diamine oxidase, pregnancy, placenta, endometrium, miscarriage, implantation, pre-eclampsia, intrauterine growth retardation, diabetes and embryonic histamine-releasing factor (EHRF). RESULTS High expression of the histamine-producing enzyme histidine decarboxylase in the placenta, histamine receptors at the feto-maternal interface and the existence of an EHRF suggest a physiological role of histamine during gestation. The balance between histamine and DAO seems to be crucial for an uncomplicated course of pregnancy. Reduced DAO activities have been found in multiple heterogeneous complications of pregnancy such as diabetes, threatened and missed abortion and trophoblastic disorders. Whether women with histamine intolerance suffer from more complicated pregnancies and higher abortion rates due to impaired DAO activities and if low DAO levels or genetic modifications in the DAO gene might therefore represent a prognostic factor for a higher risk of abortion, has not been investigated yet. CONCLUSIONS Low activities of the histamine-degrading enzyme DAO might indicate high-risk pregnancies, although high intra- and interindividual variations limit its value as a screening tool.

Gamete competence assessment by polarizing optics in assisted reproduction

BACKGROUND The purpose of this study was first to give an overview of the historical development of polarization microscopy, second to describe the various applications of this technique in assisted reproduction techniques (ART) and third to discuss the potential benefit of polarization microscopy as a predictor for IVF success. METHODS The history of polarization microscopy was undertaken by performing a backward search in the scientific literature using Google and internet sites of several Societies for Microscopy and Cell Biology. Studies of polarization microscopy in ART were identified by using a systematic literature search in PubMed and Scopus. RESULTS A total of 62 articles were identified by the direct search and further relevant articles were found by screening the cited literature in these articles. The topics relevant for assisted reproduction were spindle and zona imaging in combination with IVF success, meiotic cell cycle progression, pharmaceutical studies and cryopreservation. A separate topic was the use of sperm birefringence in ART. CONCLUSIONS The majority of studies are observational studies and were not performed in a randomized manner and there is no direct comparison of techniques using other gamete selection markers. Despite this, most studies show that polarization microscopy may help us to further increase our knowledge on gametes and meiosis. Whether certain applications such as spindle or zona imaging may lead to an increase in IVF success is unclear at present. Publications on the use of polarization microscopy on sperm are still very limited.

HLA‐G Polymorphisms: Ethnic Differences and Implications for Potential Molecule Function

PROBLEM: Human leukocyte antigen (HLA)‐G is uniquely expressed on extravillous cytotrophoblasts of the placenta and is postulated to be a mediator of maternal immune tolerance. Although it was originally considered to be nonpolymorphic, variations of the HLA‐G DNA sequence have been reported, and a limited number of HLA‐G alleles been defined.

Ethnic differences in the association of factor V Leiden mutation and the C677T methylenetetrahydrofolate reductase gene polymorphism with preeclampsia

OBJECTIVE This case-control study evaluates the association of the factor V Leiden mutation with preeclampsia and potential synergistic effects of the MTHFR-677T and factor V Leiden mutations with regard to disease risk in two different ethnic populations. STUDY DESIGN 198 women and their 143 newborns from Germany/Croatia and Indonesia with normal pregnancy or preeclampsia participated in the study. The factor V Leiden mutation was determined by direct sequencing and the MTHFR genotype by a PCR-based RFLP method. RESULTS The factor V Leiden mutation is rare in Indonesians. In Germans/Croatians, the frequency of the mutation was significantly increased in mothers with preeclampsia compared to controls. No disease association was found for combined factor V Leiden/MTHFR-677T genotypes on the maternal and fetal level. CONCLUSIONS Our results underline the need for a clear distinction of ethnicity in association studies of functional gene polymorphisms. They further support the concept of preeclampsia as a complex disease with variable contributions of disease genes in different ethnic groups.