P-033 A third of men with normospermia attending for initial fertility assessment could have DNA damage

Study question

What is the incidence of sperm DNA damage in men with normal semen analyses attending for initial fertility investigation?

Summary answer

Half of men (54%) attending for infertilty investigation had a normal semen analysis of which a third (32%) of these had abnormal sperm DNA.

What is known already

Conventional semen analysis assesses sperm concentration, motility, and morphology but with a high degree of biological variability. Around 25% of men are given a diagnosis of unexplained infertility by normal semen analysis. The World Health Organisation (WHO) stated in 2021 that ‘clinically there is a growing awareness that chromosomal anomalies and gene mutations underlie a diverse spectrum of male infertility,’ so now recommends that sperm DNA is determined as an extended analysis. Sperm DNA damage occurs more often in infertile men and DNA damage is associated with recurrent pregnancy loss and decreased live birth rates following fertility treatment.

Study design, size, duration

A prospective cohort study of men attending a secondary fertility clinic were offered a standard semen analysis plus sperm DNA fragmentation using SpermComet technology. UK IRAS ethical approval was obtained. Men attending were given a patient information leaflet at their first appointment. The study duration was 6 months. In total, 142 men were recruited out of a possible maximum of 409 attendees.

Participants/materials, setting, methods

Participants included men who had been referred as a couple to a secondary level infertility clinic for an initial assessment. Information leaflets were either posted to them prior to their first appointment or given to them at the initial nurse-led consultation. Those who subsequently contacted our research team re-attended for a sperm analysis and an aliquot was cryopreserved and sent in weekly batches to Examen (Northern Ireland) for SpermComet DNA fragmentation assessment.

Main results and the role of chance

Between May and November 2021, there were 409 attendees of whom 142 consented to the study.

Sperm DNA quality for the participants was assessed and reported as average, low and high DNA damage as a percentage compared with clinical thresholds used by Examen from their sperm bank of 63 fertile sperm donors who had recently achieved clinical pregnancies.

Of the 142 recruited, 77 men (54%) attending for initial investigations had normospermia assessed against the WHO criteria, so were initially classified as unexplained. Of these, 25 (32%) had abnormal sperm DNA values. The average comet score was 39.7% +/-1.3, low comet score was 37.8% +/- 4.4 and high comet score was 17.0% +/-2.0. These values were all significantly outside ( p < 0.001) of the fertile parameters from 63 fertile donors used by Examen (fertile range: average <26%%, low >74% and high <4%).

Our results suggest that up to a third of men reported to have normospermia will have DNA damaged sperm. This is important to consider before labelling a couple as 'unexplained'. Knowing the male's sperm DNA fragmentation assessment would allow for further discussion and exploration of lifestyle and dietary advice.

Limitations, reasons for caution

During the study period, not all attendees agreed to participate as it required an additional hospital visit. In this single site study, men have not yet been followed up for future fertility outcome such as natural conception and need or success of assisted conception.

Wider implications of the findings

Sperm DNA damage was found in a third of men who would previously have been classified as fertile and offered no further investigations or treatment to improve their sperm quality. Thus, this tool could be a useful adjunct to semen analysis to guide these couples’ future treatment pathways.

Trial registration number

not applicable

Henipavirus microsphere immuno-assays for detection of antibodies against Hendra virus

Hendra and Nipah viruses (HeV and NiV) are closely related zoonotic pathogens of the Paramyxoviridae family. Both viruses belong to the Henipavirus genus and cause fatal disease in animals and humans, though only HeV is endemic in Australia. In general and due to the acute nature of the disease, agent detection by PCR and virus isolation are the primary tools for diagnostic investigations. Assays for the detection of antibodies against HeV are fit more readily for the purpose of surveillance testing in disease epidemiology and to meet certification requirements in the international movement of horses. The first generation indirect ELISA has been affected by non-specific reactions which must be resolved using virus neutralisation serology conducted at laboratory bio-safety level 4 containment (PC4). Recent developments have enabled improvements in the available serology assays. The production of an expressed recombinant truncated HeV G protein has been utilised in ELISA and in Luminex-based multiplexed microsphere assays. In the latter format, two Luminex assays have been developed for use in henipavirus serology: a binding assay (designed for antibody detection and differentiation) and a blocking assay (designed as a surrogate for virus neutralisation). Equine and canine field sera were used to evaluate the two Luminex assays relative to ELISA and virus neutralisation serology. Results showed that Luminex assays can be effective as rapid, sensitive and specific tests for the detection of HeV antibody in horse and dog sera. The tests do not require PC4 containment and are appropriate for high throughput applications as might be required for disease investigations and other epidemiological surveillance. Also, the results show that the Luminex assays detect effectively HeV vaccine-induced antibodies.

Genetic diversity of bluetongue viruses in Australasia

The authors have characterised the genetic diversity of the bluetongue virus (BTV) RNA segments 3 and 10 from Indonesia, Malaysia and Australia. Analysis of RNA segment 3, which codes for the core protein VP3, showed conserved sequences in the previously defined Australasian topotype, but which further divided into four distinct clades or genotypes. Certain genotypes appeared to be geographically restricted while others were distributed widely throughout South-East Asia. Ongoing surveillance programmes in Australia have identified the movement of Indonesian genotypes into northern Australia and possible reassortment among them. Similarly, analysis of RNA segment 10, which codes for the non-structural protein NS3/3A, showed they were also conserved and grouped into five clades or genotypes, three Asian and two North American/South African.

Genetic diversity of bluetongue viruses in south east Asia

Bluetongue viruses (BTV) were isolated from sentinel cattle in Malaysia and at two sites in Indonesia. We identified eight serotypes some of which appeared to have a wide distribution throughout this region, while others were only isolated in Malaysia or Australia. Nearly half of the 24 known BTV serotypes have now been identified in Asia. Further, we investigated the genetic diversity of their RNA segments 3 and 10. Using partial nucleotide sequences of the RNA segment 3 (540 bp) which codes for the conserved core protein (VP3), the BTV isolates were found to be unique to the previously defined Australasian topotype and could be further subdivided into four distinct clades or genotypes. Certain of these genotypes appeared to be geographically restricted while others were distributed widely throughout the region. Similarly, the complete nucleotide sequences of the RNA segment 10 (822 bp), coding for the non-structural protein (NS3/3A), were also conserved and grouped into the five genotypes; the BTV isolates could be grouped into three Asian genotypes and two Nth American/Sth African genotypes.

Potential exposure to Australian bat lyssavirus, Queensland, 1996-1999

Two human deaths caused by Australian bat lyssavirus (ABL) infection have been reported since 1996. Information was obtained from 205 persons (mostly adults from south Brisbane and the South Coast of Queensland), who reported potential ABL exposure to the Brisbane Southside Public Health Unit from November 1,1996, to January 31, 1999. Volunteer animal handlers accounted for 39% of potential exposures, their family members for 12%, professional animal handlers for 14%, community members who intentionally handled bats for 31%, and community members with contacts initiated by bats for 4%. The prevalence of Lyssavirus detected by fluorescent antibody test in 366 sick, injured, or orphaned bats from the area was 6%. Sequelae of exposure, including the requirement for expensive postexposure prophylaxis, may be reduced by educating bat handlers and the public of the risks involved in handling Australian bats.

Characterisation of a novel lyssavirus isolated from Pteropid bats in Australia

A novel lyssavirus isolated from Pteropid bats in Australia (Australian Bat Lyssavirus, ABLV) has been characterised using gene sequence analyses, electron microscopy and a panel of monoclonal antibodies. Electron microscopic examination of Pteropid bat and mouse brain material as well as virus isolated from tissue culture medium, showed the presence of bullet-shaped rhabdovirus particles and structures characteristic of lyssavirus. Analysis using nucleocapsid (N) specific monoclonal antibodies, showed a strong relationship between this new lyssavirus and serotype 1 rabies. The nucleotide sequence of the prototype strain of ABLV was determined from the initiator methionine codon for the nucleocapsid protein (N protein) to the amino terminus of the polymerase gene (L protein), a distance of 5344 nucleotides. Comparisons of the deduced N, phosphoprotein (P), matrix protein (M), and glycoprotein (G) proteins showed that ABLV was more closely related to serotype 1 classic rabies viruses than to other members of the Lyssavirus genus. The percent relatedness of the ABLV proteins when compared to the cognate proteins of PV (Pasteur vaccine strain) rabies was 92, 75, 87 and 75% for the N, P, M and G proteins, respectively. Phylogenetic studies of N protein sequences showed clearly that ABLV is an unrecognised member of the Lyssavirus genus and represents a new genotype, genotype 7.

Antibody responses and protective immunity to recombinant vaccinia virus-expressed bluetongue virus antigens

The role of individual viral proteins in the immune response to bluetongue virus (BTV) is not clearly understood. To investigate the contributions of the outer capsid proteins, VP2 and VP5, and possible interactions between them, these proteins were expressed from recombinant vaccinia viruses either as individual proteins or together in double recombinants, or with the core protein VP7 in a triple recombinant. Comparison of the immunogenicity of the vaccinia expressed proteins with BTV expressed proteins was carried out by inoculation of rabbits and sheep. Each of the recombinants was capable of stimulating an anti-BTV antibody response, although there was a wide range in the level of response between animals and species. Vaccinia-expressed VP2 was poorly immunogenic, particularly in rabbits. VP5, on the whole, stimulated higher ELISA titers in rabbits and sheep and in some animals in both species was able to stimulate virus neutralizing antibodies. When the protective efficacy of VP2 and VP5 was tested in sheep, vaccinia-expressed VP2, VP5 and VP2 + VP5 were protective, with the most consistent protection being in groups immunized with both proteins.

Australian bat lyssavirus infection in three fruit bats from north Queensland

We report the case findings of Australian bat lyssavirus infection in two black flying foxes (Pteropus alecto) and one little red flying fox (Pteropus scapulatus) from north Queensland between January 1995 and August 1996. Although the P. alecto case in January 1995 is the first recognised case of Australian bat lyssavirus infection in Australia, this was a retrospective diagnosis made after identification of the index case at Ballina in May 1996. Eight persons had exposure to the three bats. Serum antibodies to classical rabies virus were measured in six of these persons; the only one seropositive was a veterinarian who had previously been vaccinated against rabies. Six persons received rabies vaccine following exposure. None of the in-contact humans developed signs of lyssavirus infection. For people exposed to Australian bat lyssavirus-positive bats who have not been scratched or bitten or had mucosal contamination by these bats, we suggest a post-exposure regime of five inoculations of the human diploid cell inactivated rabies vaccine.

Angiotensin-converting enzyme gene deletion polymorphism. A new risk factor for lacunar stroke but not carotid atheroma

BACKGROUND AND PURPOSE

A deletion (D)/insertion (I) polymorphism in the angiotensin-converting enzyme gene has been associated with myocardial infarction. Its relations to both stroke and atheroma remain uncertain. We examined its role as a risk factor in patients with cerebrovascular disease and its relation to carotid atheroma.

METHODS

One hundred one patients with symptomatic carotid artery territory cerebral ischemia were compared with 137 age-matched control subjects. In the patient group, carotid atheroma was assessed by measurement of degree of carotid stenosis and intima-media thickness with high-resolution duplex ultrasound. The D/I polymorphism was examined using the polymerase chain reaction.

RESULTS

D:I allele frequency was 0.59:0.41 in case subjects and 0.48:0.52 in control subjects (P = .01). The DD genotype was more common in patients with cerebrovascular disease compared with control subjects (36/101 versus 30/137, P = .02). The DD genotype conferred a relative risk of any type of cerebrovascular disease of 1.98 (95% confidence interval [CI], 1.11 to 3.51; P = .02). However, this was largely due to a strong association in the 18 patients with lacunar stroke, in whom the D:I ratio was 0.75:0.25 (P = .0097 versus control subjects). The odds ratio for lacunar stroke associated with the DD genotype was 5.6 (95% CI, 2.0 to 15.7) and was still significant at 4.40 (95% CI, 1.45 to 12.6; P < .009) after controlling for other risk factors. There was no significant association between angiotensin-converting enzyme genotype and cerebrovascular disease due to large-vessel stenosis. There was no association between genotype and age, sex, smoking history, diabetes, or cholesterol level.

CONCLUSIONS

The deletion polymorphism in the angiotensin-converting enzyme gene is a new independent risk factor for lacunar stroke but is not a risk factor for stroke associated with carotid stenosis.

Polymorphisms in the gene encoding angiotensin 1-converting enzyme and relationship to its post-translational product in cerebral infarction

There is increasing evidence to suggest that the gene encoding angiotensin 1-converting enzyme (ACE) plays a significant part in cardiac disease risk. It is not clear if this risk is due to atherosclerotic factors in general or whether its influence is local to cardiac tissue. Previous studies have suggested that there is a genetic control of plasma ACE levels in normal subjects. We sought to see if such a relationship also existed amongst computer tomography (CT) proven cerebral infarction. Twenty-eight patients with stroke and 19 control subjects were grouped according to their ACE genotype and their plasma ACE levels were assessed. Although there is a trend for plasma levels to be associated with the variant ACE alleles there was a wide overlap. However, when compared with their respective alleles in control subjects there was no difference. We conclude that any future evaluation of stroke risk from the ACE gene will need to determine both plasma ACE level and genotype.

Isolation and characterization of monoclonal antibodies against the adenovirus core proteins

Monoclonal antibodies have been prepared that recognize adenovirus core proteins V, VII, and mu in ELISA and Western blot assays. Antibodies produced by all of 87 positive hybridoma colonies obtained from a mouse injected with the precursor to protein VII, pVII, produced antibodies that also reacted with purified protein VII in an ELISA assay and all tested recognized denatured protein VII immobilized on nitrocellulose. Such failure to recover antibodies that specifically recognized only protein pVII suggests that epitopes common to the 174 amino acid protein VII and its 197 amino acid precursor were more effective antigenic determinants than the N-terminal 23 amino acid segment unique to pVII. All antibodies raised against protein mu cross-reacted with protein VII in both assays, but only a small fraction of the anti-protein VII or pVII antibodies recognized protein mu. Such cross-reactivity is discussed in relation to an unusual, arginine-rich sequence present in both protein VII and protein mu.

The grid-cell-culture technique: the direct examination of virus-infected cells and progeny viruses

We describe a method for the structural analysis and identification of viruses, without purification or concentration steps which could alter virus morphology. Virus-infected cells grown on carbon-Parlodion-coated electron microscope grids release large numbers of progeny viruses which adsorb to the surface of the grid and are revealed by negative staining. The technique is rapid, sensitive and can be used at three levels. Negative staining of whole cell preparations revealed both extracellular and intracellular viruses or nucleocapsids beneath the plasma membrane; non-ionic detergent extraction of cells infected with certain viruses reveals cytoskeleton-associated, virus-specific structures normally only observed after thin sectioning; cultures prepared by either procedure are suitable for colloidal gold immunological studies. Extracellular and cytoskeletal-associated viruses were heavily and specifically labelled with gold. The results indicate that the technique may be used to rapidly identify unknown viruses on the basis of size, topography, morphology and mode of maturation from the infected cell, as well as the presence of characteristic intracellular cytoskeletal-associated structures. The technique also has potential use in the sero-grouping and sero-typing of viruses with specific monoclonal antibodies.

Worldwide early detection of cervical cancer

Data available to the World Health Organization on frequency of cancers of the cervix in developing countries are incomplete and fragmentary. There are many indications that cancers of the cervix represent problems of a public health dimension in these countries. With a few exceptions, screening efforts are low-volume institution-based cytology services reaching limited segments of the female population. On the other hand, the recognized risk factors for cancer of the cervix are widely prevalent in developing countries. Cultural and educational constraints often bar women from seeking medical attention. Diagnostic and treatment facilities, particularly radiotherapy, and all levels of trained staff have been insufficient to permit screening programs for cancers of the cervix. Development of future programs must ensure their integration into existing health infrastructures.

Rubella arthritis in adults. Isolation of virus, cytology and other aspects of the synovial reaction

Rubella virus was isolated from three consecutive samples of synovial fluid after 1 to 4 days of arthritis in adults with typical naturally acquired rubella. In the two samples suitably prepared, cells in the synovial fluid were mononuclear, with numerous monocytes and macrophages. Detailed studies in one case revealed a close similarity in all respects to the illness caused by Ross River virus, another member of the Togaviridae. Cells in the synovial exudate of this patient showed intense phagocytosis. A fine nodular cytoplasmic distribution of virus antigen was detected by immunofluorescence in 45% of the cells. There was no depletion of the complement components C'3 and C'4 in serum or synovial fluid, and no evidence of excessive immune complexes in the circulation or of immune-complex uptake by cells in the synovial exudate or intima. Synovial intima from the suprapatellar region merely showed slight hyperplasia without cellular infiltration, indicating that the lodgement of virus and the inflammatory cellular reaction to it can be confined to limited regions of the synovial lining, at least in the early stages.

A new method for estimation of fetal weight in late pregnancy by ultrasonic scanning

The biparietal diameter and are of the fetal skull, and the area of the fetal thorax, were measured by ultrasonic scanning in 68 patients in the seven days prior to delivery. These parameters and various expressions based on the skull and thoracic areas were related to birth weight. It was concluded that the skull and thoracic areas multiple (STAM) index was a more efficient predictor of birth weight than the biparietal diameter.

Through-knee amputation

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