P-112 Utilizing surgical sperm retrieval to improve clinical outcomes for men with high sperm chromatin fragmentation in their ejaculates

Study question

In men with elevated sperm chromatin fragmentation (SCF), can surgical sperm retrieval from the proximal area of the male genital tract improve clinical outcomes?

Summary answer

Spermatozoa retrieved from the epididymis or testes demonstrate higher genomic integrity and are associated with enhanced embryo implantation, clinical pregnancy, and delivery rates.

What is known already

Sperm genomic integrity is a key factor in achieving a successful pregnancy. During spermiogenesis, alteration of DNA topology involving nuclease and ligase mechanisms is required for supercoiling and DNA compaction. If a proper DNA repair mechanism fails during this intricate process, spermatozoa with DNA fragmentation should be picked up by the epididymis and phagocytized. When this mechanism fails, along with the presence of superimposed reactive oxygen species in the male genital tract, spermatozoa with DNA fragmentation may reach the ejaculates. We have previously demonstrated that retrieving spermatozoa directly from the epididymis and testes yields gametes with higher conserved genomic integrity.

Study design, size, duration

In a nine-year timespan, we identified over 1,000 men with high SCF in their ejaculates; 144 patients consented to undergo surgical retrieval of spermatozoa. In a preliminary assessment, their clinical outcomes were compared to those from men with normal SCF (n = 539). Of these men, 53 consented to undergo subsequent ICSI cycles with their female partners using surgically retrieved spermatozoa from the epididymis (n = 15) or testes (n = 38). Fertilization and clinical outcomes were compared.

Participants/materials, setting, methods

Ejaculated, epididymal, and testicular specimens were screened by terminal deoxynucleotidyl dUTP nick-end labeling (TUNEL) to assess SCF using a commercially available kit. A total of 500 spermatozoa/sample were screened with a normal threshold of 15%. Surgical samples from the epididymis and testes were cryopreserved in multiple vials for subsequent ICSI cycles.

Main results and the role of chance

In the preliminary assessment, ICSI outcomes utilizing ejaculated spermatozoa were compared between men with normal (n = 539, 9.3±3%) and abnormal (n = 144, 28.2±13%) SCF. Although fertilization did not differ, implantation (24.1% vs. 7.8%) and clinical pregnancy rates (CPR, 35.8% vs. 14.6%) were significantly impaired (P < 0.001) in men with elevated SCF.

SCF assessment on surgically retrieved spermatozoa revealed a decreasing trend from 28.2±13% in the ejaculate to 16.6±9.2% in the epididymis and 10.1±5.7% in the testes.

A total of 53 men underwent 79 subsequent ICSI cycles using surgically retrieved spermatozoa. Compared to their historical cycles using ejaculates (n = 65), ICSI with surgically retrieved sperm substantially improved implantation (18.8% vs. 2.1%; P < 0.001), CPR (36.5% vs. 5.3%; P < 0.0001), and ongoing/delivery rates (33.8% vs. 4.1%; P < 0.0001).

Among these couples, 15 underwent 21 ICSI cycles utilizing epididymal spermatozoa with a mean SCF of 16.6±9%. Implantation (26.5% vs. 3.7%; P < 0.05), CPR (68.4% vs. 4.2%; P < 0.0001), and ongoing/delivery rates (57.1% vs. 4.2%; P < 0.0001) were significantly improved compared to the historical cycles.

The remaining 38 patients underwent ICSI with testicular spermatozoa with an average SCF of 10.1±6%. Implantation (15.0% vs. 2.6%; P < 0.01), CPR (25.5% vs. 6.1%; P < 0.01), and ongoing/delivery rates (23.6% vs. 3.0%; P < 0.05) were higher when compared to historical cycles.

Limitations, reasons for caution

Although surgically retrieved spermatozoa can be used to enhance clinical outcomes in couples with high SCF, epididymal spermatozoa yielded higher pregnancy rates despite the higher level of SCF in these specimens compared to testicular spermatozoa. This can be explained by the corrective action of the ICSI procedure itself.

Wider implications of the findings

Our study demonstrated that sperm DNA integrity progressively increases through the journey of the male genital tract. In couples with a compromised sperm genome, surgically retrieved spermatozoa can be beneficial. Therefore, assessing SCF might be used a routine tool to evaluate the male gamete.

Trial registration number

N/A

Design and internal validation of an obstetric early warning score: secondary analysis of the Intensive Care National Audit and Research Centre Case Mix Programme database

We designed and internally validated an aggregate weighted early warning scoring system specific to the obstetric population that has the potential for use in the ward environment. Direct obstetric admissions from the Intensive Care National Audit and Research Centre's Case Mix Programme Database were randomly allocated to model development (n = 2240) or validation (n = 2200) sets. Physiological variables collected during the first 24 h of critical care admission were analysed. Logistic regression analysis for mortality in the model development set was initially used to create a statistically based early warning score. The statistical score was then modified to create a clinically acceptable early warning score. Important features of this clinical obstetric early warning score are that the variables are weighted according to their statistical importance, a surrogate for the FI O2 /Pa O2 relationship is included, conscious level is assessed using a simplified alert/not alert variable, and the score, trigger thresholds and response are consistent with the new non-obstetric National Early Warning Score system. The statistical and clinical early warning scores were internally validated using the validation set. The area under the receiver operating characteristic curve was 0.995 (95% CI 0.992-0.998) for the statistical score and 0.957 (95% CI 0.923-0.991) for the clinical score. Pre-existing empirically designed early warning scores were also validated in the same way for comparison. The area under the receiver operating characteristic curve was 0.955 (95% CI 0.922-0.988) for Swanton et al.'s Modified Early Obstetric Warning System, 0.937 (95% CI 0.884-0.991) for the obstetric early warning score suggested in the 2003-2005 Report on Confidential Enquiries into Maternal Deaths in the UK, and 0.973 (95% CI 0.957-0.989) for the non-obstetric National Early Warning Score. This highlights that the new clinical obstetric early warning score has an excellent ability to discriminate survivors from non-survivors in this critical care data set. Further work is needed to validate our new clinical early warning score externally in the obstetric ward environment.

Characterization of low-molecular-weight glutenin genes in Aegilops tauschii

This paper reports the characterization of the low-molecular-weight (LMW) glutenin gene family of Aegilops tauschii (syn. Triticum tauschii), the D-genome donor of hexaploid wheat. By analysis of bacterial artificial chromosome (BAC) clones positive for hybridization with an LMW glutenin probe, seven unique LMW glutenin genes were identified. These genes were sequenced, including their untranslated 3' and 5' flanking regions. The deduced amino acid sequences of the genes revealed four putative active genes and three pseudogenes. All these genes had a very high level of similarity to LMW glutenins characterized in hexaploid wheat. The predicted molecular weights of the mature proteins were between 32.2 kDa and 39.6 kDa, and the predicted isoelectric points of the proteins were between 7.53 and 8.06. All the deduced proteins were of the LMW-m type. The organization of the seven LMW glutenin genes appears to be interspersed over at least several hundred kilo base pairs, as indicated by the presence of only one gene or pseudogene per BAC clone. Southern blot analysis of genomic DNA of Ae. tauschii and the BAC clones containing the seven LMW glutenin genes indicated that the BAC clones contained all LMW glutenin-hybridizing bands present in the genome. Two-dimensional gel electrophoresis of an LMW glutenin extract from Ae. tauschii was conducted and showed the presence of at least 11 distinct proteins. Further analysis indicated that some of the observed proteins were modified gliadins. These results suggest that the actual number of typical LMW glutenins may in fact be much lower than previously thought, with a number of modified gliadins also being present in the polymeric fraction.

Prenatal ultrasound diagnosis of abdominal aortic aneurysm with fibrotic occlusion in aortic branch vessels

In a 35-year-old multiparous patient, an ultrasound scan performed at 32 weeks' gestational age for size less than dates revealed an appropriately grown fetus with a two-vessel umbilical cord. Also noted were dilated, tortuous abdominal and pelvic vessels. A scan at 33.5 weeks confirmed the two-vessel cord and noted a widely dilated abdominal aorta and a left foot 2 cm shorter than the right. Delivery at 36 weeks was followed by a neonatal course complicated by thromboses, renovascular hypertension, and a newly patent ductus with pulmonary hypertension. Successful ligation was followed by acute pulmonary hypertension, cardiac dysfunction and death. Autopsy findings included aneurysmal dilation of the abdominal aorta without evidence of arterial wall pathology.

Tissue mast cells in breast cancer

The total number of mast cells and the number of such cells observed within and at the periphery of invasive breast cancers from 424 patients enrolled in protocol 4 of the National Surgical Adjuvant Breast Project were correlated with 38 other pathologic and 6 clinical features. High total mast cell counts as well as those within and at the periphery of the cancers were found to be significantly (p less than or equal to .05) associated with a patient age less than 50 years and the degree of tumor lymphoid cell reaction. The latter has also been found to be related to young age and other pathologic characteristics related to mast cell content. This suggests that the mast cells may simply represent another cell type of this reactive change. No differences in 10 year disease-free survival were detected in patients without mast cells and those exhibiting varying numbers of such cells. This information indicates that identifiable mast cells do not represent a prognostic pathologic discriminant in patients with breast cancer. However, this does not unequivocally exclude a role of mast cell secretory products, since only intact and not degranulated or disrupted forms of these cells can be counted.

Objective pathological diagnosis of coal worker's pneumoconiosis

Pertinent pathological features of lungs obtained at autopsies from 99 coal miners were compared with those observed in the lungs of 268 male town dwellers of comparable age who were not occupationally related to the coal mining or other industries at risk for development of pneumoconiosis. The degree of anthracotic pigment deposition and severity of type of pigmented lesion with its accompanying reticulum fiber formation and fibrosis were significantly greater in lungs of miners. There was a high degree of overlap in degree of pigment deposition, particularly those quantitated as grades 1 and 2 and in lesions regarded as types 1 and 2. The greatest divergence was observed for prevalence of nodular pulmonary lesions (type 4). There was also a considerable divergence in the type 3 alteration characterized by nonnodular aggregates of carbon-laden macrophages accompanied by minimal reactive fibrosis. It appears that an objective pathological diagnosis of coal workers' pneumoconiosis (CWP) can be rendered only by the demonstration of type 4 lesions. Approximately 25% of coal miners exhibited unequivocal features of CWP. No significant differences concerning incidence or types of emphysema or frequency of chronic cor pulmonale were encountered between the two populations.