Multicentric, prospective observational data show sperm capacitation predicts male fertility, and cohort comparison reveals a high prevalence of impaired capacitation in men questioning their fertility

RESEARCH QUESTIONS

Can a previously defined relationship between sperm capacitation and the probability of a man generating pregnancy within three cycles, prospectively predict male fertility in diverse clinical settings? A second study asked, what is the prevalence of impaired sperm fertilizing ability in men questioning their fertility (MQF), and does this relate to traditional semen analysis metrics?

DESIGN

In the multicentric, prospective observational study, data (n = 128; six clinics) were analysed to test a published relationship between the percentage of fertilization-competent, capacitated spermatozoa (Cap-Score) and probability of generating pregnancy (PGP) within three cycles of intrauterine insemination. Logistic regression of total pregnancy outcomes (n = 252) assessed fit. In the cohort comparison, Cap-Scores of MQF (n = 2155; 22 clinics) were compared with those of 76 fertile men.

RESULTS

New outcomes (n = 128) were rank-ordered by Cap-Score and divided into quintiles (25-26 per group); chi-squared testing revealed no difference between predicted and observed pregnancies (P = 0.809). Total outcomes (n = 252; 128 new + 124 previous) were pooled and the model recalculated, yielding an improved fit (P < 0.001). Applying the Akaike information criterion found that the optimal model used Cap-Score alone. Cap-Scores were performed on 2155 men (with semen analysis data available for 1948). To compare fertilizing ability, men were binned by PGP (≤19%, 20-29%, 30-39%, 40-49%, 50-59%, ≥60%). Distributions of PGP and the corresponding Cap-Scores were significantly lower in MQF versus fertile men (P < 0.001). Notably, 64% of MQF with normal volume, concentration and motility (757/1183) had PGP of 39% or less (Cap-Scores ≤31), versus 25% of fertile men.

CONCLUSIONS

Sperm capacitation prospectively predicted male fertility. Impaired capacitation affects many MQF with normal semen analysis results, informing diagnosis versus idiopathic infertility.

The dual trigger study: Rationale and study design of a prospective double-blind randomized clinical trial comparing pregnancy rates after co-administration of low dose hCG at the time of GnRH agonist trigger or 35 h later for the prevention of OHSS

Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication of controlled ovarian stimulation. The use of gonadotropin releasing hormone (GnRH) agonist for the trigger of oocyte maturation is effective in the prevention of OHSS although it may result in a lower pregnancy rate. The use of adjuvant low dose human chorionic gonadotropin (hCG) at the time of trigger or at the time of oocyte retrieval may improve pregnancy rates. The goal of this dual trigger study is to evaluate the safety and efficacy of the use of low dose hCG administered at the time of GnRH agonist trigger or 35 h later as well as the potential impact on pregnancy rates. The population will consist of 82 women undergoing IVF treatment who are at risk of developing OHSS. This study will be a single center prospective randomized double-blind placebo controlled trial. The randomization schedule will be administered by the Investigational Drug Services of the University. After controlled ovarian stimulation, induction of oocyte maturation will be achieved using a GnRH agonist and patients will be randomized to receive either low dose hCG 1000 IU at the time of trigger and placebo at oocyte retrieval (Study group) or placebo at the time of trigger and hCG 1500 IU at the time of oocyte retrieval (Control group). The main outcomes will be live birth rates and incidence of OHSS. Two ancillary studies will include a quality of life survey and serum assessment of independent corpus luteum function.

Reactivation of maternal SNORD116 cluster via SETDB1 knockdown in Prader-Willi syndrome iPSCs

Prader-Willi syndrome (PWS), a disorder of genomic imprinting, is characterized by neonatal hypotonia, hypogonadism, small hands and feet, hyperphagia and obesity in adulthood. PWS results from the loss of paternal copies of the cluster of SNORD116 C/D box snoRNAs and their host transcript, 116HG, on human chromosome 15q11-q13. We have investigated the mechanism of repression of the maternal SNORD116 cluster and 116HG. Here, we report that the zinc-finger protein ZNF274, in association with the histone H3 lysine 9 (H3K9) methyltransferase SETDB1, is part of a complex that binds to the silent maternal but not the active paternal alleles. Knockdown of SETDB1 in PWS-specific induced pluripotent cells (iPSCs) causes a decrease in the accumulation of H3K9 trimethylation (H3K9me3) at 116HG and corresponding accumulation of the active chromatin mark histone H3 lysine 4 dimethylation (H3K4me2). We also show that upon knockdown of SETDB1 in PWS-specific iPSCs, expression of maternally silenced 116HG RNA is partially restored. SETDB1 knockdown in PWS iPSCs also disrupts DNA methylation at the PWS-IC where a decrease in 5-methylcytosine is observed in association with a concomitant increase in 5-hydroxymethylcytosine. This observation suggests that the ZNF274/SETDB1 complex bound to the SNORD116 cluster may protect the PWS-IC from DNA demethylation during early development. Our findings reveal novel epigenetic mechanisms that function to repress the maternal 15q11-q13 region.

Treatment of endometriosis: a hormonal approach

Endometriosis continues to plague women of reproductive age. It is a chronic disease leading to a decreased quality of life, infertility, and increased societal costs. The gold standard for diagnosis remains visualization and or biopsy of lesions at the time of intraoperative diagnosis, i.e. laparoscopy or laparotomy. The severity of pain does not correlate with the stage of endometriosis, which complicates the treatment process. Hormonal therapies have long been used as a treatment for endometriosis. Therapy is targeted at symptom relief as a cure is lacking. While some regimes use hormonal therapy exclusively, others combine such with surgical excision of lesions. Although hormonal modalities are successful in alleviating or suppressing symptoms, they fail to treat the infertility associated with endometriosis. Therefore, those, desiring to achieve pregnancy should be excluded from hormonal treatment in the short term. Future studies are needed to understand the pathophysiology and allow design of specific, targeted treatment.

Low-dose remifentanil infusion does not impair natural killer cell function in healthy volunteers

BACKGROUND

Mu opioid agonists suppress natural killer (NK) cell activity in animal models. Studies in human volunteers, however, have yielded conflicting results, with morphine suppressing and fentanyl increasing NK cell activity. This study evaluated the effect of a constant 8-h infusion of remifentanil on NK cell number and function in human volunteers.

METHODS

After IRB approval and informed consent was obtained, 10 healthy volunteers underwent an 11 pm to 7 am infusion of saline, and at least 1 week later an infusion of 0.02-0.04 microg x kg(-1) min(-1) remifentanil. Blood was collected at 7 am for measurement of NK cell cytotoxicity using a (51)Cr release assay and measurement of NK cell number using fluorescent flow cytometry.

RESULTS

Median and range of the total NK cell cytotoxicity (KU ml(-1)) was 745.0 (498.3-1483.6) on the control morning and 818.6 (238.5-1454.5) on the morning following the remifentanil infusion. Neither the number of NK cells ml(-1) (2.5 x 10(5) (1.4 x 10(5)-4.2 x 10(5)) vs 2.7 x 10(5) (1.1 x 10(5)-4.4 x 10(5))) nor the cytotoxicity per 1000 NK cells (KU 1000 NK cells(-1)) (3.0 (1.8-5.2) vs 2.9 (0.9-6.7)) changed between the control and remifentanil conditions.

CONCLUSIONS

An 8-h infusion of remifentanil did not affect NK cell activity in normal volunteers. This result differs from previous findings of morphine-induced NK cell activity suppression and fentanyl-induced NK cell activity enhancement in normal volunteers.