Does dual oocyte retrieval with continuous FSH administration increase the number of mature oocytes in low responders? An open-label randomized controlled trial

STUDY QUESTION

Is there an increase in the total number of metaphase II (MII) oocytes between a conventional ovarian stimulation (OS) and a double uninterrupted stimulation?

SUMMARY ANSWER

There is no increase in the total number of MII oocytes when comparing one conventional OS to a continuous stimulation with double oocyte aspiration.

WHAT IS KNOWN ALREADY

Based on the concept of multiple follicular waves, the combination of two stimulations in the same ovarian cycle has gained interest in patients with a low ovarian reserve. This so-called dual stimulation approach is usually characterized by a discontinuation of FSH administration for ∼5 days and appears to have a favourable impact on the number of retrieved oocytes without affecting the embryo quality or ploidy status. The outcomes of dual uninterrupted OS have not yet been studied.

STUDY DESIGN, SIZE, DURATION

This was an open-label randomized controlled trial (RCT) with superiority design, performed in a single tertiary centre. Subjects were randomized with a 1:1 allocation into two groups between October 2019 and September 2021. All patients underwent a conventional stimulation with recombinant FSH. When two or more follicles of 17 mm were present, the final inclusion criterion was assessed; randomization occurred only in the presence of ≤9 follicles of ≥11 mm. In Group A, ovulation was triggered with hCG, and oocyte retrieval (OR) was performed 34-36 h later, followed by a fresh single or double embryo transfer (SET or DET) on Day 3/5. In Group B, ovulation was triggered with GnRH agonist, followed by another OS, without discontinuation of the FSH administration. In the presence of one or more follicles of ≥17 mm, the second stimulation was completed with hCG. A freeze-all strategy (Day 3/5) was applied for both retrievals, followed by transfer of one or two embryos in an artificially prepared frozen-thawed cycle. In the absence of one or more follicles of ≥17 mm after 13 additional days of stimulation, the second cycle was cancelled. All ORs were executed by a senior fertility specialist who was blinded for the first treatment, and all follicles >10 mm were aspirated, according to routine clinical practice. The primary outcome was the total number of MII oocytes. Patients were followed up until all embryos were transferred, or until live birth was achieved. Other secondary outcomes included the number of cumulus-oocyte complexes (COCs), the number of good quality embryos (Day 3/5), the ongoing pregnancy rate, and gonadotropin consumption.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients between 25 and 40 years old, with an anti-Müllerian hormone level of ≤1.5 ng/ml, antral follicle count of ≤6, or ≤5 oocytes after a previous stimulation, were included. At the start, 70 patients were eligible for participation in the trial, of whom 48 patients fulfilled the final inclusion criterium and were randomized. After drop-out of two patients, 23 patients were randomized to a single round of OS (Group A), and 23 patients were randomized to two uninterrupted rounds of OS (Group B).

MAIN RESULTS AND THE ROLE OF CHANCE

Baseline characteristics were similar between both groups. The cumulative number of COCs and MII oocytes after completion of the second OR was similar in Group A and Group B [5.3 ± 2.7 versus 5.3 ± 3.0 (P = 0.95); 4.1 ± 2.4 versus 4.3 ± 2.7 (P = 0.77)]. Likewise, a comparable number of excellent and good quality embryos was available on Day 3 (3.0 ± 2.0 versus 2.7 ± 2.0; P = 0.63). In Group B, the cancellation rate due to insufficient response to the second round of stimulation was 39.1% (9/23). When focusing on the first stimulation in both groups, there were no significant differences regarding basal FSH, gonadotropin consumption, and the number of preovulatory follicles. After the first OR, the mean number of COC and MII oocytes was significantly higher in Group A (who had hCG triggering), compared to Group B (who had GnRH agonist triggering) [5.3 ± 2.7 versus 3.3 ± 2.2; difference 95% CI (0.54 to 3.45), P = 0.004 and 4.1 ± 2.4 versus 3.0 ± 2.2; difference 95% CI (-0.15 to 2.6), P = 0.05, respectively]. Likewise, the number of excellent and good quality embryos on Day 3 was significantly higher (3.0 ± 2.0 versus 1.9 ± 1.7; P = 0.02) in Group A.

LIMITATIONS, REASONS FOR CAUTION

This study was powered to demonstrate superiority for the number of MII oocytes after dual stimulation. Investigating the impact of dual stimulation on pregnancy rates would have required a larger sample size. Furthermore, the heterogeneity in embryo vitrification and transfer policies precluded a correct comparison of embryologic outcomes between both groups.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first RCT investigating the role of continuous stimulation with double aspiration in low responders. Our results show no statistically significant differences in the cumulative number of MII oocytes between one conventional stimulation with fresh ET and two consecutive stimulations with a freeze-only approach. Furthermore, the observed suboptimal oocyte yield after agonist ovulation triggering in low responders in the dual uninterrupted OS group is a reason for concern and further scrutiny, given that previous RCTs have shown similar outcomes in normal and high responders after hCG and GnRH agonist triggers.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported in part by a research grant from Organon. H.T. received honoraria for lectures and presentations from Abbott, Cooper Surgical, Gedeon-Richter, Cook, Goodlife, and Ferring. L.B. received fees for lectures from Merck & Organon and support for attending ESHRE 2023. M.D.V. reports fees for lectures from Ferring, Merck, Organon, IBSA, Gedeon Richter, and Cooper Surgical and support for attending ASRM 2023. S.M. received honoraria for lectures and presentations from Abbott, Cooper Surgical, Gedeon-Richter, IBSA, and Merck. C.B. was on the Advisory board and received consulting fees from Theramex and received honoraria for lectures and presentations from Abbott, Ferring, Gedeon-Richter, IBSA, and Merck.

TRIAL REGISTRATION NUMBER

NCT03846544.

TRIAL REGISTRATION DATE

19 February 2019.

DATE OF FIRST PATIENT’S ENROLMENT

28 October 2019.

Enzymatic tissue processing after testicular biopsy in non-obstructive azoospermia enhances sperm retrieval

STUDY QUESTION

What is the added value of enzymatic processing of testicular biopsies on testicular sperm retrieval (SR) rates for patients with non-obstructive azoospermia (NOA)?

SUMMARY ANSWER

In addition to mechanical mincing, enzymatic digestion increased SR rates in testicular biopsies of NOA patients.

WHAT IS KNOWN ALREADY

Many studies focus on the surgical approach to optimize recovery of testicular sperm in NOA, and in spite of that, controversy still exists about whether the type of surgery makes any difference as long as multiple biopsies are taken. Few studies, however, focus on the role of the IVF laboratory and the benefit of additional lab procedures, e.g. enzymatic digestion, in order to optimize SR rates.

STUDY DESIGN SIZE DURATION

This retrospective single-center cohort study included all patients who underwent their first testicular sperm extraction (TESE) by open multiple-biopsy method between January 2004 and July 2022. Only patients with a normal karyotype, absence of Y-q deletions and a diagnosis of NOA based on histology were included. The primary outcome was SR rate after mincing and/or enzymes. The secondary outcome was cumulative live birth (CLB) after ICSI with fresh TESE and subsequent ICSI cycles with frozen TESE.

PARTICIPANTS/MATERIALS SETTING METHODS

Multiple biopsies were obtained from the testis, unilaterally or bilaterally, on the day of oocyte retrieval. Upon mechanical mincing, biopsies were investigated for 30 min; when no or insufficient numbers of spermatozoa were observed, enzymatic treatment was performed using Collagenase type IV. Multivariable regression analysis was performed to predict CLB per TESE by adjusting for the following confounding factors: male FSH level, female age, and requirement of enzymatic digestion to find sperm.

MAIN RESULTS AND THE ROLE OF CHANCE

We included 118 patients, of whom 72 (61.0%) had successful SR eventually. Spermatozoa were retrieved after mechanical mincing for 28 patients (23.7%; 28/118) or after additional enzymatic digestion for another 44 patients (37.2%; 44/118). Thus, of the 90 patients requiring enzymatic digestion, sperm were retrieved for 44 (48.9%). Male characteristics were not different between patients with SR after mincing or enzymatic digestion, in regard to mean age (34.5 vs 34.5 years), testis volume (10.2 vs 10.6 ml), FSH (17.8 vs 16.9 IU/l), cryptorchidism (21.4 vs 34.1%), varicocele (3.6 vs 4.6%), or histological diagnosis (Sertoli-cell only 53.6 vs 47.7%, maturation arrest 21.4 vs 38.6%, sclerosis/atrophy 25.0 vs 13.6%).Of the 72 patients with sperm available for ICSI, 23/72 (31.9%) achieved a live birth (LB) after the injection with fresh testicular sperm (and fresh or frozen embryo transfers). Of the remaining 49 patients without LB, 34 (69.4%) had supernumerary testicular sperm frozen. Of these 34 patients, 19 (55.9%) continued ICSI with frozen testicular sperm, and 9/19 (47.4%) had achieved an LB after ICSI with frozen testicular sperm. Thus, the total CLB was 32/118 (27.1%) per TESE or 32/72 (44.4%) per TESE with sperm retrieved.Of the female characteristics (couples with sperm available), only female age (30.3 vs 32.7 years; P = 0.042) was significantly lower in the group with a LB, compared to those without.The CLB with testicular sperm obtained after enzymatic digestion was 31.8% (14/44), while the CLB with sperm obtained after mincing alone was 64.3% (18/28). Multivariable logistic regression analysis showed that when enzymatic digestion was required, it was associated with a significant decrease in CLB per TESE (OR: 0.23 (0.08-0.7); P = 0.01).

LIMITATIONS REASONS FOR CAUTION

Limitations of the study are related to the retrospective design. However, the selection of only patients with NOA, and specific characteristics (normal karyotype and absence Y-q deletion) and having their first TESE, strengthens our findings.

WIDER IMPLICATIONS OF THE FINDINGS

Enzymatic processing increases the SR rate from testicular biopsies of NOA patients compared to mechanical mincing only, demonstrating the importance of an appropriate laboratory protocol. However, NOA patients should be counseled that when sperm have been found after enzymatic digestion, their chances to father a genetically own child may be lower compared to those not requiring enzymatic digestion.

STUDY FUNDING/COMPETING INTERESTS

None reported.

TRIAL REGISTRATION NUMBER

N/A.

A global perspective on bacterial diversity in the terrestrial deep subsurface

While recent efforts to catalogue Earth's microbial diversity have focused upon surface and marine habitats, 12-20 % of Earth's biomass is suggested to exist in the terrestrial deep subsurface, compared to ~1.8 % in the deep subseafloor. Metagenomic studies of the terrestrial deep subsurface have yielded a trove of divergent and functionally important microbiomes from a range of localities. However, a wider perspective of microbial diversity and its relationship to environmental conditions within the terrestrial deep subsurface is still required. Our meta-analysis reveals that terrestrial deep subsurface microbiota are dominated by Betaproteobacteria, Gammaproteobacteria and Firmicutes, probably as a function of the diverse metabolic strategies of these taxa. Evidence was also found for a common small consortium of prevalent Betaproteobacteria and Gammaproteobacteria operational taxonomic units across the localities. This implies a core terrestrial deep subsurface community, irrespective of aquifer lithology, depth and other variables, that may play an important role in colonizing and sustaining microbial habitats in the deep terrestrial subsurface. An in silico contamination-aware approach to analysing this dataset underscores the importance of downstream methods for assuring that robust conclusions can be reached from deep subsurface-derived sequencing data. Understanding the global panorama of microbial diversity and ecological dynamics in the deep terrestrial subsurface provides a first step towards understanding the role of microbes in global subsurface element and nutrient cycling.

P-253 Shorter duration of compaction during human in-vitro preimplantation embryo development is associated with a higher clinical pregnancy rate

Study question

Is the duration of compaction, KID- (Known Implantation Data) and iDAScore (Intelligent Data Analysis for embryo evaluation) associated to clinical pregnancy rate?

Summary answer

Duration of compaction, KID- or iDAScore can be used to select the best embryo for transfer to increase clinical pregnancy rate.

What is known already

The development of human preimplantation embryos follows a programmed timeline in which a series of critical events occur. Compaction is a typical event at 3 to 4 days post fertilisation that is characterised by flattening of the blastomeres and the formation of tight junctions between the blastomeres. It is considered the first morphological event in the differentiation process of the embryo. Time-lapse technology introduced continuous monitoring of the embryo throughout development in the IVF laboratory. Evaluation of the developmental events combined with calculating KID- and iDAScore can optimise the selection of the most competent embryos for transfer and/or cryopreservation.

Study design, size, duration

This single-centre retrospective observational study included 158 IVF/ICSI cycles with fresh single embryo transfer (SET) was performed between December 2018 and November 2021. Embryos were cultured during 5 days in cleavage/blastocyst medium (Coopersurgical) in the EmbryoScope + (Vitrolife). Transferred embryos were evaluated for start of compaction, time to full compaction and duration of compaction. Embryo quality was calculated using KID- and iDAScore. These parameters were compared between the clinically pregnant and non-pregnant group (primary outcome).

Participants/materials, setting, methods

Only IVF/ICSI cycles with ejaculated sperm and fresh SET on day 5 were included. MNC, IVM and PGT cycles were excluded. Time zero was the start of injection or insemination. Pregnancy was confirmed by hCG and clinical pregnancy was defined by gestational sac visualisation at ultrasound.

GraphPad Prism and R-studio were used for statistical analysis. For prediction of clinical pregnancy, univariate logistic regression was used. Other significant differences were determined using t-test.

Main results and the role of chance

Out of 158 fresh ET, 101 (63.9%) had a positive hCG, of which 88 (55.6%) achieved clinical pregnancy. All 158 transferred blastocysts were annotated to calculate KID- and iDAScore.

There was no statistical difference in age between the two groups (34.7 years vs 35.0 years; p = 0.69).

Start of compaction was heterogeneous (between 50.9 and 98.3 hours post injection/insemination; mean=76.5±7.7), as well as the blastomere number at its initiation (between 4 and 16 blastomeres; mean=11.8±2.1).

Univariate logistic regression showed that each individual parameter, i.e. duration of compaction (p = 0.02), KID-score (p = 0.001) and iDAScore (p = 0.0006) was different between the clinically pregnant and non-pregnant group.

The total duration of compaction was significantly shorter in the clinical pregnant group (mean=8.6±3.4 hours vs 10.2±4.7 hours; p = 0.01; t-test). In the pregnant group the KIDscore (mean=7.7±1.4 vs 6.7±2.3; p = 0.0007) and iDAScore (mean=8.9±0.7 vs 8.3±1.3; p = 0.0002) were significantly higher.

During partial compaction, cells were rather excluded (93%) than extruded from the process; 17 embryos underwent this process, 10 of which resulted in a clinical pregnancy.

Limitations, reasons for caution

As this is a retrospective study, the influence of uncontrolled variables cannot be excluded. In the future, different models will be applied that can combine duration of compaction, KID- and iDAScore in a larger study.

Wider implications of the findings

Our analysis confirms previous findings that KID- and iDAScore are good predictors of clinical pregnancy.

We also show that duration of compaction can be used as a potential predictor for pregnancy, especially in IVF clinics that have no access to KID- or iDAScore.

Trial registration number

not applicable

O-177 Towards 3D Reconstructions of Human Preimplantation Embryo Development

Study question

Can we use focal stacks collected through Hoffman modulation contrast (HMC) microscopy to generate 3D reconstructions of preimplantation embryos?

Summary answer

A machine learning system was designed to generate 3D meshes that approximate the structures of embryos captured on HMC microscopes up to the 8-cell stage. 

What is known already

The 3D arrangement of cells in preimplantation human embryos is a topic of clinical interest, with significant associations between the cell arrangement and blastulation potential from as early as the 4-cell stage. In basic research, the use of confocal microscopy for generating 3D reconstructions is commonplace. However, the use of confocal microscopy in the IVF clinic is often infeasible due to cost and concerns for embryos’ wellbeing. The assessment of 3D cell arrangement in clinical settings can thus prove difficult and time-consuming as many embryologists rely on focal stacks captured through the HMC microscopes widely integrated into incubators. 

Study design, size, duration

The study was a retrospective analysis of 581 Embryoscope focal stacks of embryos from 4 clinics collected between 2018 and 2020. The number of planes in each stack ranged from 7-11 and cell outlines were annotated along with the depths at which they were most in-focus. A deep learning system was designed to generate 3D reconstructions of the embryos. Two clinics’ data were used for training (N = 551) and the others’ for evaluation (N = 30).

Participants/materials, setting, methods

The deep learning system consisted of three stages: a super-resolution module, a cell segmentation module and a depth regression module. The super-resolution stage was used to predict missing planes in focal stacks that did not contain 11 focal planes; the segmentation module identified individual cells; the depth regression module identified the focal plane at which each cell was most “in-focus”. Meshes were then generated under the assumption that blastomeres’ dimensions are similar along each axis.

Main results and the role of chance

The superresolution module was evaluated by calculating the structural similarity index (SSIM; an image similarity measure ranging from 0-1) between predicted and true planes when tasked with predicting missing frames in focal stacks with up to 4 planes artificially removed (by uniform random sampling). The module achieved an SSIM of 0.80. The predictions were also evaluated by 2 embryologists, a clinician and a developmental biologist on a scale of 1-5 (1=very unrealistic; 3=usable; 5=very realistic), achieving a mean score of 4.11.

The segmentation module was evaluated on the proportion of cells it managed to identify (91%) as well as the mean overlap between predicted cell segmentations and the ground truth (intersection-over-union of 0.86). The depth module was evaluated on the mean deviation of predictions from the true most “in-focus” plane (0.73 planes).

3D reconstructions generated by the system were evaluated with reference to the original focal stacks by 2 embryologists on a 1-5 scale similar to before, with a mean score of 3.72. The most common issues with the reconstructions identified by the embryologists were missing cells/fragments, incorrect cell shape due to obstruction by the well’s edge and imprecise depth predictions (with the “true” depth being between focal planes).

Limitations, reasons for caution

As previously mentioned, some reconstructions had inaccuracies. These would likely be ameliorated through modifications to the system modules and more training data. Moreover, the system was not trained or evaluated on morulae/blastocysts. Finally, each focal stack was analysed independently - future work may examine enforcing temporal consistency within timelapses. 

Wider implications of the findings

This work serves as a first step towards unlocking data captured in IVF clinics for research into cell arrangement in preimplantation embryos. Combined with cell tracking, the system may be useful for research into cell fate. Moreover, the work may find clinical relevance in enabling easier assessment of cell arrangement.

Trial registration number

N/A

P-780 Ten years electronic witnessing in the IVF laboratory

Study question

What did we learn after 10 years of electronic witnessing?

Summary answer

Only when applied correctly, electronic witnessing can prevent sample mix-up.

What is known already

In the early days of IVF, manual double witnessing was used to reduce the misidentification of gametes for insemination. However, risk for human errors due to fatigue, automatism, distraction or work load make this a mistake-prone approach. Hence, there is increasing interest in using electronic witnessing systems for patient and sample identification. Although not always mandatory, such systems have been implemented in many fertility laboratories to avoid identification errors. A mismatch is generated when non-matching samples are simultaneously present in a single workstation. Yet, when the system is incorrectly used, corrective intervention by an administrator (administrator assign) may be required.

Study design, size, duration

This evaluation investigates the mismatch (MM) rate and administrator assigns (AA) over a 10-year period (March 2011- December 2021) with the use of RI Witness (RIW) (CooperSurgical). Radio frequency identification tags (RFID) were used for patient and sample identification. Conventional IVF and ICSI cycles, and frozen embryo cycles (FET) were included since 10 years, IUI cycles since 8 years.

Participants/materials, setting, methods

The total number of tags and witness points (WP) were recorded. Witness points represent all the actions in RIW that have been performed during the entire process. MM and AA were collected and stratified by procedure (sperm preparation, oocyte retrieval, IVF/ICSI, (embryo)biopsy, vitrification/warming, embryo transfer, medium changeover and IUI). Critical MM (such as mis-labeling or non-matching samples within one work area) and critical AA (such as non-RIW-identified samples and unconfirmed WP) were selected.

Main results and the role of chance

A total of 109,655 cycles were included: 53,023 IVF/ICSI, 36,347 FET, and 20,285 IUI cycles. The 724,096 used tags, led to a total of 849,650 WP. The overall MM rate per WP was 0.25% (2,132/849,650), 1.9% per cycle, of which 144 critical mismatches occurred in the different procedures: sperm preparation: 66, oocyte retrieval: 5, IVF/ICSI: 33, (embryo)biopsy: 1, vitrification/warming: 26, embryo transfer: 8, medium changeover: 3 and IUI: 2. The mean critical MM rate per WP per year was 0.017% ± 0.007% and 0.13 ± 0.05% per cycle. The overall AA rate per WP was 0.11% (940/849,650), 0.86% per cycle, including 320 critical assigns: sperm preparation: 83, oocyte retrieval: 34, IVF/ICSI: 173, (embryo)biopsy: 3, vitrification/warming: 6, embryo transfer: 0, medium changeover: 21. Critical AA rate per year was on average 0.041%/WP ± 0.01% and 0.30 ± 0.07% per cycle. All MM and AA rates remained stable during this 10-year period, except for sperm preparation, where the removal of a single witness point led to a huge increase in AA. RIW should still be used in combination with the manual labelling of bottom and lid of dishes and tubes to guarantee correct assignment in case of RFID malfunction or AA.

Limitations, reasons for caution

The procedures and method of integration of RIW may vary from one laboratory to another and result in differences in the potential risks. RIW cannot (yet) identify individual embryos, making double manual witnessing indispensable at certain critical steps, where potential errors are not recorded.

Wider implications of the findings

Using an electronic witnessing is considered to be the ultimate tool to safeguard correct identification of gametes and embryos. But this is only possible when used correctly and requires proper training and attention of the staff. It may also induce new risks, i.e. blind witnessing of samples by the operator.

Trial registration number

not applicable

P-281 A multi-centre evaluation of a novel 4-cell embryo classification system based on intercellular contact points

Study question

Is there any prognostic value to classifying 4-cell embryos according to intercellular contact points (ICPs)?

Summary answer

A significant association was found between the new blastomere arrangement classifications and blastulation, as well as blastocyst quality. No significant association was found for pregnancy.

What is known already

Current literature states that the geometric arrangement of blastomeres in 4-cell embryos is usually classified as either “tetrahedral” or “non-tetrahedral/planar”. Though tetrahedral embryos have been associated with greater developmental capacity, their prevalence has varied between studies. At ESHRE 2021, Hickman et al. proposed a more fine-grained classification system; each class was associated with a 4-digit code, where the Nth digit in said code gave the number of cells with N-1 ICPs. This gave rise to 6 classes: tetrahedral (0004), pseudotetrahedral (0022), planar (0040), closed-Y (0121), open-Y (0301) and linear (0220). In our study, we evaluate this new system.

Study design, size, duration

This study was a retrospective analysis of 844 4-cell embryos across 3 clinics in 3 countries. Focal stacks of the embryos were captured on Embryoscope/MIRI time-lapse incubators between 2018 and 2020. Embryos were annotated by their respective clinics using the original “tetrahedral/planar” system. Additionally, data on blastulation, blastocyst grade (Gardner scale) and biochemical pregnancy rates were obtained for each embryo.

Participants/materials, setting, methods

The embryos were annotated according to the new system by a panel of three researchers without knowledge of the clinics’ or each other’s classifications. Afterwards, the panelists assembled for discussion and a unanimous consensus was reached for each embryo. The cell arrangement classes were analysed with respect to blastulation rates, blastocyst grade and pregnancy rates using chi-squared tests. The distribution of classes across the clinics was also analysed, as well as agreement among the panelists.

Main results and the role of chance

Under the new system, tetrahedral and pseudotetrahedral embryos saw significantly higher rates of blastulation (P = 0.017) and good-quality blastocysts (p = 0.043; here, “good-quality” means that the grade contains no ‘C’s or numbers less than 3) compared to other arrangements. No association was found with respect to biochemical pregnancy (p = 0.77).

There was significant variation between the clinic-provided classifications (p < 0.001) with tetrahedral-to-planar ratios ranging from 1 to 9. Under the new system, there was no significant difference between the proportions of each arrangement (p = 0.66). The arrangements in order of decreasing prevalence across all the data were tetrahedral (63.7%), pseudotetrahedral (25.8%), planar (8.0%), closed-Y (2.2%) and linear (0.3%). No open-Y embryos were observed. Upon comparison with the clinic-provided tetrahedral/planar classifications, there were clear differences in the treatment of pseudotetrahedral embryos - some clinics predominantly classified them as “tetrahedral” while others as “planar”.

Prior to any discussions, the panelists’ annotations unanimously agreed on the classifications of 63% of the embryos; with 33% of the embryos having 2 different classifications and 4% of embryos causing total disagreement. The majority of disagreements regarded pseudotetrahedral embryos being confused for either tetrahedral or planar embryos.

Limitations, reasons for caution

It can be at times difficult to visualise the 3D structure of embryos from focal stacks. As a result, some annotations may be erroneous, though the use of a panel-based approach helped to mitigate this. Moreover, further studies will need to take place to validate the findings in this work.

Wider implications of the findings

The findings demonstrate the prognostic utility of Hickman et al.’s ICP-based classification system. Moreover, the findings suggest that much of the variability seen in the prevalence of tetrahedral embryos under the tetrahedral/planar system came from the mislabelling of pseudotetrahedral embryos which comprised 25.8% of the study population.

Trial registration number

N/A

P–259 Blastocyst quality is associated with both the start and the duration of compaction after ICSI

Study question

Is the start and the total duration of compaction related to embryo quality?

Summary answer

The timing of the start, the end and the total duration of compaction are associated with blastocyst quality grade in the IVF laboratory.

What is known already

Preimplantation embryo development follows a programmed timeline during which a series of critical events take place. One event typically occurring on day 3/4 post fertilisation is the formation of adherence junctions between blastomeres in a process called compaction. It is considered the first morphological event in the differentiation process of the mammalian embryo. Evaluation of developmental events are used to optimize the selection of the most competent embryos for transfer and/or cryopreservation in the IVF laboratory. It has already been shown that the time of full compaction is indicative for high-quality blastocysts with a higher implantation rate.

Study design, size, duration

A single-centre retrospective observational study including 74 ICSI cycles performed in 2020. Injected oocytes were cultured in blastocyst medium (Origio) in the EmbryoScope + (Vitrolife) for 5/6 days. Embryos that reached the blastocyst stage were evaluated for the start of compaction, the time to reach full compaction and the total duration of compaction. These parameters were compared between good- and poor-quality blastocysts; the primary outcome parameter of the study was embryo quality.

Participants/materials, setting, methods

Only ICSI cycles with ejaculated fresh/frozen-thawed sperm and monitored in time-lapse incubator were included. All MNC, IVM and PGT cycles were excluded. Time zero was the start of ICSI. Good-quality embryos were full and expanded blastocysts with good-quality inner cell mass and trophectoderm (AA, AB, BA and BB according to Gardner and Schoolcraft (1999)). GraphPad Prism was used for statistical analysis. After testing for normality and homogeneity, unpaired t-test or Mann-Whitney test determined significant differences.

Main results and the role of chance

In this study, of the 528 included 2PN oocytes, 229 (43.4%) reached the blastocyst stage and 299 (56.6%) were arrested. Among the former, 131 (57.2%) blastocysts were classified in the good-quality group and 98 (42.8%) blastocysts in the poor-quality group. In general, human embryos compacted slowly while dividing further and the blastomeres moved during the compaction process. The start of compaction was heterogeneous (between 50.9 and 102.7 hours post ICSI; mean=80.0 hours), as well as the cell number at the initiation (between 4 and 18 blastomeres; mean=12 blastomeres). The time analysis showed that the embryos in the good-quality group started to compact significantly earlier than those in the poor-quality group (mean=78.6 vs 82.2 hours; R²=0.06; p < 0.01). We confirmed that blastocysts in the good-quality group reached full compaction earlier than those in the poor-quality group (mean=86.8 vs 93.8 hours; R²=0.17; p < 0.01). Furthermore, the total duration of compaction was significantly lower in the good-quality than in the poor-quality group (median=7.4 vs 10.7 hours; p < 0.01).

Limitations, reasons for caution

As this is a retrospective study, the influence of uncontrolled variables cannot be excluded. The absence of the pregnancy outcome and live birth rate is a shortcoming and will be subject of a larger patient-to-patient study.

Wider implications of the findings: These results indicate that an earlier start and a shorter duration of compaction are associated with better blastocyst quality. These morphological events can be valuable additional parameters in selecting the embryo of better quality when using a time-lapse incubator.

Trial registration number

Not applicable

Plant-based sterols and stanols in health & disease: "Consequences of human development in a plant-based environment?"

Dietary plant sterols and stanols as present in our diet and in functional foods are well-known for their inhibitory effects on intestinal cholesterol absorption, which translates into lower low-density lipoprotein cholesterol concentrations. However, emerging evidence suggests that plant sterols and stanols have numerous additional health effects, which are largely unnoticed in the current scientific literature. Therefore, in this review we pose the intriguing question "What would have occurred if plant sterols and stanols had been discovered and embraced by disciplines such as immunology, hepatology, pulmonology or gastroenterology before being positioned as cholesterol-lowering molecules?" What would then have been the main benefits and fields of application of plant sterols and stanols today? We here discuss potential effects ranging from its presence and function intrauterine and in breast milk towards a potential role in the development of non-alcoholic steatohepatitis (NASH), cardiovascular disease (CVD), inflammatory bowel diseases (IBD) and allergic asthma. Interestingly, effects clearly depend on the route of entrance as observed in intestinal-failure associated liver disease (IFALD) during parenteral nutrition regimens. It is only until recently that effects beyond lowering of cholesterol concentrations are being explored systematically. Thus, there is a clear need to understand the full health effects of plant sterols and stanols.

Case series on acute HCV in HIV-negative men in regular clinical practice: a call for action

BACKGROUND

The evidence that HIV treatment as prevention (TasP) and HIV pre-exposure prophylaxis (PrEP) reduces the risk of HIV transmission is overwhelming. But as PrEP and TasP can lead to increased sexual mixing between HIV positive and negative men who have sex with men (MSM), sexually transmitted infections such as acute hepatitis C (HCV), which were thought to be limited to HIV-infected MSM, could become more frequent in HIV uninfected MSM as well. The objective of this study was to describe a series of cases of sexually transmitted HCV infections in HIV-uninfected MSM in the Netherlands and Belgium.

METHODS

Through the Dutch Acute HCV in HIV Study (a Dutch-Belgian prospective multicentre study on the treatment of acute HCV infection, NCT02600325) and the Be-PrEP-ared study (a PrEP project in Antwerp, EudraCT2015-000054-37) several acute HCV infections were detected in HIV-negative men.

RESULTS

A newly acquired HCV infection was diagnosed in ten HIV-negative MSM. HCV was diagnosed at a sexually transmitted infection (STI) clinic (n = 2), by their general practitioner (n = 2), by their HIV physician (n = 1) or at a PrEP clinic (n = 5). Ten patients reported unprotected anal intercourse and four had a concomitant STI at the time of HCV diagnosis. Six patients reported using drugs during sex.

CONCLUSIONS

Our observation calls for a larger nationwide epidemiological study on the prevalence, incidence and risk factors of HCV infection in HIV-uninfected MSM. In the changing landscape of TasP and PrEP, reliable and up-to-date epidemiological data on HCV among HIV-uninfected MSM are needed and will help in developing evidence-based testing policies.

Abdominal subcutaneous and visceral adipocyte size, lipolysis and inflammation relate to insulin resistance in male obese humans

Obesity is associated with a disturbed adipose tissue (AT) function characterized by adipocyte hypertrophy, an impaired lipolysis and pro-inflammatory phenotype, which contributes to insulin resistance (IR). We investigated whether AT phenotype in different AT depots of obese individuals with and without type 2 diabetes mellitus (T2DM) is associated with whole-body IR. Subcutaneous (SC) and visceral (V) AT biopsies from 18 lean, 17 obese and 8 obese T2DM men were collected. AT phenotype was characterized by ex vivo measurement of basal and stimulated lipolysis (mature adipocytes), adipocyte size distribution (AT tissue sections) and AT immune cells (flow cytometry). In VAT, mean adipocyte size, CD45⁺ leukocytes and M1 macrophages were significantly increased in both obese groups compared to lean individuals. In SCAT, despite adipocyte hypertrophy, no significant differences in immune cell populations between groups were found. In SCAT, multiple linear regression analysis showed that none of the AT phenotype markers independently contributed to HOMA-IR while in VAT, mean adipocyte size was significantly related to HOMA-IR. In conclusion, beside adipocyte hypertrophy in VAT, M1 macrophage- or B-cell-mediated inflammation, may contribute to IR, while inflammation in hypertrophic SCAT does not seem to play a major role in IR.

Impact of childhood trauma on course of panic disorder: contribution of clinical and personality characteristics

OBJECTIVE

To investigate the impact of childhood trauma on the clinical course of panic disorder and possible contributing factors.

METHOD

Longitudinal data of 539 participants with a current panic disorder were collected from the Netherlands Study of Depression and Anxiety (NESDA). Childhood trauma was assessed with a structured interview and clinical course after 2 years with a DSM-IV-based diagnostic interview and the Life Chart Interview.

RESULTS

At baseline, 54.5% reported childhood trauma, but this was not predictive of persistence of panic disorder. Emotional neglect and psychological abuse were associated with higher occurrence of anxiety disorders other than panic disorder (social phobia) and with higher chronicity of general anxiety symptoms (anxiety attacks or episodes and avoidance). Baseline clinical features (duration and severity of anxiety and depressive symptoms) and personality traits (neuroticism and extraversion) accounted for roughly 30-60% of the total effect of childhood trauma on chronicity of anxiety symptoms and on occurrence of other anxiety disorders.

CONCLUSION

After two years, childhood trauma is associated with chronicity of anxiety symptoms and occurrence of social phobia, rather than persistence of panic disorder. These relationships are partially accounted for by duration and severity of anxiety and depressive symptoms, and neuroticism and extraversion.

SolCos model-based individual reminiscence for older adults with mild to moderate dementia in nursing homes: a randomized controlled intervention study

WHAT IS KNOWN ON THE SUBJECT?: To stimulate reminiscence of older adults with dementia performed individually or through group sessions is a well-known practice in nursing homes resulting in effects on behaviour and well-being as an alternative for medication. Robust scientific proof of the effectiveness of individual reminiscence therapy performed in nursing homes is sparse. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: We have provided individual standardized reminiscence therapy to residents with dementia. The therapy was developed and tested in a previous study and performed in this study by trained nursing home volunteers. In comparison with a control group who received usual care, residents who received the reminiscence therapy showed significant less depressive symptoms. Moreover, residents were, in general, attentive, open and collaborative during the sessions and volunteers experienced the sessions as useful and pleasant. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Individual reminiscence therapy can be learned and used by nursing home volunteers to improve care in nursing homes.

ABSTRACT

Aim To investigate the effect of a standardized individualized intervention based on the SolCos transformational reminiscence model on depressive symptoms (primary outcome), cognition and behaviour (secondary outcomes) for older people with mild to moderate dementia, performed by trained nursing home volunteers as facilitators. Background Because of limited pharmacological treatment options for older adults with dementia relevant physical, sensory, psychological or social interventions offer alternative opportunities. Method Randomized controlled trial (ISRCTN74355073) was set up in two nursing homes with 29 and 31 residents in the intervention and the control groups respectively. Eighteen nursing home volunteers were trained to perform the reminiscence therapy. Various assessment scales were measured pre- and post-sessions. Results Linear regression analysis showed an impact on depressive symptoms. However, no impact was identified on cognition and behaviour. Facilitators experienced the sessions as useful and pleasant, and study participants were, in general, attentive, open and collaborative. Discussion Study results showed that organizing standardized individual reminiscence therapy with nursing home volunteers was feasible and study participants' attention and participation were overall good. Further study initiatives to explore the potential of individual reminiscence therapy within a person-centred framework are recommended in order to improve care in nursing homes.

Direct comparison of conventional radiography and cone-beam CT in small bone and joint trauma

OBJECTIVE

To compare the diagnostic value of cone-beam computed tomography (CBCT) and conventional radiography (CR) after acute small bone or joint trauma.

MATERIALS AND METHODS

Between March 2013 and January 2014, 231 patients with recent small bone or joint trauma underwent CR and subsequent CBCT. CR and CBCT examinations were independently assessed by two readers, blinded to the result of the other modality. The total number of fractures as well as the number of complex fractures were compared, and inter- and intraobserver agreement for CBCT was calculated. In addition, radiation doses and evaluation times for both modalities were noted and statistically compared.

RESULTS

Fracture detection on CBCT increased by 35% and 37% for reader 1 and reader 2, respectively, and identification of complex fractures increased by 236% and 185%. Interobserver agreement for CBCT was almost perfect, as was intraobserver agreement for reader 1. The intraobserver agreement for reader 2 was substantial. Radiation doses and evaluation time were significantly higher for CBCT.

CONCLUSION

CBCT detects significantly more small bone and joint fractures, in particular complex fractures, than CR. In the majority of cases, the clinical implication of the additionally detected fractures is limited, but in some patients (e.g., fracture-dislocations), the management is significantly influenced by these findings. As the radiation dose for CBCT substantially exceeds that of CR, we suggest adhering to CR as the first-line examination after small bone and joint trauma and keeping CBCT for patients with clinical-radiographic discordance or suspected complex fractures in need of further (preoperative) assessment.

Quality assessment of colonoscopy in Flanders: a voluntary survey among Flemish gastroenterologist

Colonoscopy is an important endoscopic examination for the diagnosis and treatment of pathological conditions of the colon, like polyps and colorectal cancer. However, several factors determine the quality of colonoscopy and thus the quality of polyp and colorectal cancer detection. The Flemish Society of Gastroenterology (VVGE) performed a voluntary on-line registry among its members to identify quality of colonoscopy in Flanders, Belgium. 64 gastroenterologists voluntarily registered 4276 consecutive colonoscopies performed during a 3 month study period. Colonoscopy quality indicators were prospectively collected and analysed. Results showed a low voluntary participation rate (17%), acceptable overall adenoma detection rate of 20,5% and colorectal cancer interval rate of 5,4%. Complications were low (perforation 0,1% and major bleeding 1,5%). The current study showed that in Flanders, Belgium on-line registration of colonoscopy quality indicators is feasible and that quality of colonoscopy in daily practice meets the expectations of (inter)national guidelines. However, further improvement of the registry and an open debate on the quality control of colonoscopy in Flanders is warranted (Belgian Registry B30020096548).

Validation and translation of the Dutch tinnitus functional index

OBJECTIVES

Several questionnaires are used to survey how tinnitus affects quality of life, making comparisons across studies difficult. The questionnaires also are used to measure treatment outcome but were not designed for this purpose. To address these issues, a new questionnaire has been suggested, the tinnitus functional index (TFI), which is highly responsive to treatment-related change. The current study aim was to translate and validate the TFI for a Dutch-speaking population. Factor analysis was performed to characterize the TFI profile in a large tinnitus population.

METHODS

The questionnaire was translated using a translation-back translation procedure, and 263 patients in the ENT department of Antwerp University Hospital with tinnitus-related complaints completed it. Factor structure was assessed using exploratory analysis with oblique rotation and compared with the original questionnaire. Internal consistency was measured using Cronbach's alpha coefficient. Spearman correlations with the percentage of time aware of the tinnitus and the visual analogue scales (VAS) for maximum tinnitus loudness and mean tinnitus loudness were calculated to investigate convergent validity.

RESULTS

The original eight-factor structure could be confirmed in the Dutch version of the TFI. Internal consistency (a=0.96) and convergent validity showed good results. Statistically significant correlations were found with the VAS for maximum loudness (r=0.59; p<0.001), VAS for mean loudness (r=0.66; p<0.001), and percentage of time aware of tinnitus (r=0.58; p<0.001).

CONCLUSIONS

The Dutch version of the TFI is suitable for measuring in clinical and research settings how tinnitus affects daily life, with psychometric properties in line with the original version.

Prevalence of residual excessive sleepiness during effective oral appliance therapy for sleep-disordered breathing

BACKGROUND

Oral appliance therapy with a mandibular advancement device (OAm) can yield to complete therapeutic response (apnea-hypopnea index [AHI]<5 events/h), though some patients show little or no improvement in daytime sleepiness. The prevalence of residual excessive sleepiness (RES) despite effective treatment with OAm therapy is unknown. We aimed to determine the prevalence of RES in patients treated with a titratable custom-made duobloc OAm.

METHODS

A prevalence study was performed, collecting data from 185 patients with an established diagnosis of sleep-disordered breathing (SDB) under OAm therapy with a titratable custom-made duobloc device (baseline data were male:female ratio, 129:56; age, 48±9 years; body mass index [BMI], 27±4 kg/m2; Epworth Sleepiness Scale [ESS] score, 10±5; and AHI, 19±12 events/h). A full-night polysomnography was performed at baseline and after 3 months of OAm therapy. Daytime sleepiness was assessed using the ESS with RES defined as an ESS score of 11 or higher out of 24, despite complete therapeutic response.

RESULTS

Out of 185 patients, 84 patients (45%) showed a complete therapeutic response with an AHI of <5 events per hour after 3 months of OAm therapy. Despite this normalization of AHI, 27 out of these 84 patients (32%) showed RES and had a significantly higher baseline ESS (15±4 vs. 9±4; P<.001) and were younger (43±9 vs. 47±9; P=.028) compared to patients without RES.

CONCLUSION

RES under OAm therapy showed a prevalence of up to 32% in SDB patients effectively treated with respect to AHI. Patients with RES were younger and had higher baseline daytime sleepiness.

Work engagement supports nurse workforce stability and quality of care: nursing team-level analysis in psychiatric hospitals

Research in healthcare settings reveals important links between work environment factors, burnout and organizational outcomes. Recently, research focuses on work engagement, the opposite (positive) pole from burnout. The current study investigated the relationship of nurse practice environment aspects and work engagement (vigour, dedication and absorption) to job outcomes and nurse-reported quality of care variables within teams using a multilevel design in psychiatric inpatient settings. Validated survey instruments were used in a cross-sectional design. Team-level analyses were performed with staff members (n = 357) from 32 clinical units in two psychiatric hospitals in Belgium. Favourable nurse practice environment aspects were associated with work engagement dimensions, and in turn work engagement was associated with job satisfaction, intention to stay in the profession and favourable nurse-reported quality of care variables. The strongest multivariate models suggested that dedication predicted positive job outcomes whereas nurse management predicted perceptions of quality of care. In addition, reports of quality of care by the interdisciplinary team were predicted by dedication, absorption, nurse-physician relations and nurse management. The study findings suggest that differences in vigour, dedication and absorption across teams associated with practice environment characteristics impact nurse job satisfaction, intention to stay and perceptions of quality of care.

Using conventional HIV tests on oral fluid

There is need for more evaluations of non-invasive tests in order to broaden the reach of testing programs and to perform large scale epidemiological studies. In this study, three different human immunodeficiency virus (HIV) enzyme linked immunosorbent assays (ELISAs) and one line immunoassay were evaluated to detect HIV antibodies in oral fluid samples. Specimens were collected, after informed consent was obtained, with the Oracol (MMD, Worcester, England) device. A total IgG quantitation test was performed to demonstrate the quality of the sample. Assessment of a modified protocol of the Vironostika HIV Ag/Ab, Enzygnost Anti-HIV 1/2 Plus Genscreen HIV-1/2 Version 2 and a line immune confirmatory assay the INNO-LIA HIV I/II score was done, using oral fluid specimens of 325 HIV positive and negative individuals. For the ELISAs, the addition of an extra internal oral fluid control was evaluated as well as different cut-offs, time between sampling and testing and the effect of drinking water just before sampling. Finally, the confirmatory test and some testing algorithms and combination of tests were discussed. The results obtained from the oral fluid specimens were compared with the gold standard on paired serum specimens. Firstly, there was no significant difference observed between the use of the kit controls and the oral fluid controls. New protocols and calculation of cut-offs were defined for two of the three ELISAs. High sensitivities and specificities were obtained with all three ELISAs without any statistical difference between the three tests. Secondly, no statistically significant difference was observed when samples were stored for different time periods between sampling and testing, meaning that a period of seven days at room temperature before testing is still acceptable. Thirdly, drinking water before sample collection did not interfere with the testing, although lower optical densities were observed. None of the positive samples were missed. In addition, the line immunoassay INNO-LIA HIV I/II score test is a promising test for confirmation of reactive oral fluid specimen, but more samples need to be validated in order to adapt the interpretation rules specifically for oral fluid specimens. Different choices/algorithms adapted for the purpose of testing can be proposed. In conclusion, it can be said that the commercial ELISAs with adapted protocol and cut-off values are suitable tools for making HIV test performance accessible to people. With this non-invasive sampling method, more eligible individuals can and will be selected for further HIV test on blood.

Prospective observational study of treatment pattern, effectiveness and safety of zoledronic acid therapy beyond 24 months in patients with multiple myeloma or bone metastases from solid tumors

PURPOSE

To study the treatment patterns, effectiveness and safety of zoledronic acid (ZOL) beyond 2 years of therapy, given the paucity of data on long-term treatment in daily clinical practice.

METHODS

Patients with multiple myeloma (MM) or solid tumor bone metastases (STM) and at least 24 months of regular q3-4w ZOL therapy were followed prospectively for an additional 18 months beyond the 24 months required for study entry. End-points included ZOL exposure, incidence of skeletal related events (SRE), and safety.

RESULTS

In all, 298 evaluable patients were enrolled. The mean continuation rate of ZOL was 90.6%. Exposure to ZOL decreased with time in all patients, but was lower (50.0% vs. 67.6%; p<0.001) and with higher discontinuation rates (incidence rate ratio [IRR]=1.95; p=0.002) in MM compared to the STM group. ZOL suppressed the rate of SREs similarly during the study as compared to before inclusion (0.12 vs. 0.13 events per person-year; p=0.7). At 18 months, 84.5% remained SRE-free. In STM patients, persistent ZOL therapy was associated with lower SRE risk (hazard ratio [HR]=0.42; p=0.01), but not in MM. Renal deterioration occurred in 3.7% and osteonecrosis of the jaw (ONJ) developed in 6.0%, with dental trauma increasing ONJ risk (HR=4.67; p=0.002).

CONCLUSIONS

Beyond 2 years of therapy, treatment patterns of ZOL were heterogeneous and SRE rates were low. The safety profile of ZOL was acceptable, and interrupting ZOL in patients with solid tumors was associated with a higher risk of SREs.

Treatment of obstructive sleep apnea using a custom-made titratable duobloc oral appliance: a prospective clinical study

PURPOSE

This prospective clinical study investigates the efficacy of a specific custom-made titratable mandibular advancement device (MAD) for the treatment of obstructive sleep apnea (OSA). This MAD has attachments in the frontal teeth area that allow for progressive titration of the mandible.

METHODS

Sixty-one adult OSA patients were included (age, 46.7 ± 9.0 years; male/female ratio, 45/16; apnea-hypopnea index (AHI), 23.2 ± 15.4 events/h sleep; body mass index, 27.9 ± 4.1 kg/m²). After an adaptation period, titration started based on a protocol of symptomatic benefit or upon reaching the physiological limits of protrusion. As a primary outcome, treatment response was defined as an objective reduction in AHI following MAD treatment of ≥50 % compared to baseline, and treatment success as a reduction in AHI with MAD to less than 5 and 10 events/h sleep. Compliance failure was defined as an inability to continue treatment.

RESULTS

A statistically significant decrease was observed in AHI, from 23.4 ± 15.7 at baseline to 8.9 ± 8.6 events/h with MAD (p < 0.01). Treatment response was achieved in 42 out of 61 patients (68.8 %), whereas 42.6 % met criteria of AHI < 5 and 63.9 % achieved an AHI < 10 events/h sleep, respectively. Four patients (6.6 %) were considered as "compliance failures."

CONCLUSIONS

The present study has evaluated the efficacy of a specific custom-made titratable MAD in terms of sleep apnea reduction.

Abstract P3-13-01: Prospective study of treatment pattern, effectiveness, and safety of zoledronic acid (ZOL) therapy beyond 24 months: subgroup analysis of patients (pts) with metastatic bone disease (MBD) from breast cancer (BC)

Background: Trial data documenting ZOL treatment in pts with MBD from BC is currently limited to approximately 2 years of therapy.

Materials and Methods: The prospective multicenter LOTUZ trial studied pts with multiple myeloma or MBD from a solid tumor (n = 298), and with at least 24 months of regular q3-4w ZOL therapy. Follow-up was 18 months and ZOL could be continued, interrupted or stopped at the discretion of the treating physician. End-points included ZOL exposure (% of expected per-label cumulative dose) and persistence (no treatment interruptions &gt; 45 days), incidence of skeletal related events (SRE), and safety. Here we present the results for the subgroup of BC pts.

Results: A total of 157 women (median age 62y; range 38 — 87y) were included in this analysis (204 person-years follow-up). The mean continuation rate of ZOL at any visit was 92.1% (95% CI 90.3 — 93.9), even though only 37.0% of pts who completed follow-up (n = 108) received uninterrupted per-label ZOL therapy. On average, exposure to ZOL decreased with 2.23% per 3 months on study (95% CI 0.93 — 3.54; p = 0.001). ZOL infusions were extended beyond 15 minutes in 36.1% (95% CI 33.7 — 38.6), and the treatment interval exceeded 4 weeks in 28.4% of pts (95% CI 19.6 — 38.6). Overall, ZOL continued to suppress the rate of SREs similarly during the 18 months study period (0.127 per person-year) as compared to the 18 months before inclusion (0.135 per person-year; p = 0.8). Radiation to bone occurred most frequently (46.2%) out of a total of 26 observed SREs. At 18 months, 83.3% (95% CI 75.6 — 88.8) of pts were SRE free. Both higher exposure to ZOL (HR 0.76 per 20% increase; 95% CI 0.62 — 0.93; p = 0.009) and persistent ZOL therapy (HR 0.26; 95% CI 0.11 — 0.60; p = 0.002) were associated with significantly lower SRE risk, compared to pts receiving lower dosed or interrupted therapy. Renal deterioration occurred in 6 pts (event rate 0.03 per person-year; 95% CI 0.01 — 0.07), with a numerically higher risk when ZOL dose was not adjusted for renal function (HR 3.54; 95% CI 0.65 — 19.4; p = 0.14), as observed in 11.5% of pts. Symptomatic hypocalcemia was not reported, even though adherence to supplemental calcium and vitamin D was only 15.9%. Acute phase reactions were infrequent (9.5%) and ONJ developed in 7 pts (4.5%). Invasive dental procedures or trauma numerically increased ONJ risk (HR 2.87; p = 0.3), with a risk of ONJ of 11.1% (95% CI 0.2 — 48.2%) after any of these events.

Conclusion: The continuation rate of ZOL beyond two years of therapy is high and ZOL demonstrated continued effectiveness in maintaining low SRE rates. Nevertheless, ZOL treatment patterns were heterogeneous and deviating from per-label ZOL therapy resulted in a higher SRE risk. The long-term safety profile of ZOL was favorable, but adequate prevention strategies for ONJ remain important.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-13-01.

Impact of type D personality on adherence to oral appliance therapy for sleep-disordered breathing

PURPOSE

Type D personality, defined as a combination of social inhibition and negative affectivity, has been associated with poor medication adherence and lower adherence to continuous positive airway pressure in patients with sleep-disordered breathing. Up to this date, the association of patient's personality with adherence with a mandibular advancement device (MAD) has not been studied. The purposes of this study were to examine the association between type D personality and poor adherence to MAD treatment and to examine the impact of type D personality on perceived side effects during this treatment.

METHODS

Eighty-two patients out of 113 patients with a known baseline type D scale who have started MAD treatment between June 2006 and December 2009 were included. Information about side effects and adherence were collected via a postal questionnaire. Thirty-three patients were using a monobloc MAD and 49 patients were using a duobloc MAD.

RESULTS

Forty-five percent of type D patients discontinued MAD treatment, whereas only 15 % of non-type D patients reported treatment discontinuation. The odds ratio for treatment discontinuation was 6.03 (95 % confidence interval 1.22-29.81; p = 0.027) for type D personality, adjusted for age, gender, MAD type (monobloc or duobloc), and decrease in apnea severity. In continuing MAD users, no significant difference in perceived side effects was reported between the personality types.

CONCLUSION

This is the first study to examine the relationship between type D personality and adherence to MAD treatment. Type D patients reported a significantly higher discontinuation rate when compared to patients without type D personality.

Voluntary outreach counselling and testing for HIV and STI among men who have sex with men in Antwerp

BACKGROUND

High risk settings for transmission of HIV and sexually transmitted infections (STI) offer an opportunity for screening of difficult to reach risk groups.

METHODS

Free, anonymous counselling and testing for HIV, syphilis, Chlamydia and hepatitis B/C were offered to visitors in two selected gay venues in Antwerp, by a multidisciplinary team. Participants completed an anonymous questionnaire. The STI-test results were communicated by cell phone using standardised text messages.

RESULTS

In total, 137 MSM were tested. Facilitators of risky sexual behaviour (alcohol and drug use) were reported by 34 and 21%, respectively. Four men (3%) were newly diagnosed with HIV; 25 men (18%) had an active, transmittable STI. Infected MSM were significantly less often registered with a fixed general practitioner (GP).

CONCLUSIONS

Outreach testing in gay venues is a suitable method to detect MSM at risk for HIV/STI. Although the outreach approach is very labour intensive, it shows a high yield of new STI-diagnoses that are not detected in the regular health system.

Grading and characterization of soft tissue tumors on magnetic resonance imaging: the value of an expert second opinion report

Objective

To retrospectively compare the accuracy of the initial MRI (magnetic resonance imaging) report of referring radiologists and the second opinion report.

Material and methods

MRI of 155 patients presenting with a soft tissue tumor (STT) in a single large community center were referred for inclusion in the Belgian Soft Tissue Neoplasm Registry (BSTNR). The initial report and the second opinion report were made independently. Histopathology (gold standard) was obtained in 90 patients (group 1). In 65 patients, the diagnosis was made by the combination of clinical findings and/or follow-up (group 2). In group 1, the concordance in grading and tissue-specific (TS) diagnosis between the referring center (RC) and expert center (EC) was reviewed.

Results

In group 1, MR grading yields a sensitivity of 100% and a specificity of 89% in the EC. The sensitivity was 88% and the specificity 81% in the RC. The accuracy was significantly higher in the EC (92%) compared to the RC (83%) (p = 0.039). The TS diagnosis was correct in 50% versus 38.5% of malignant tumors and in 71.8% versus 51.6% of benign tumors in the EC and RC respectively.

Conclusion

A second opinion report increases the accuracy in the diagnosis of STT on MRI.

Main Messages

• A second opinion MRI report increases the overall accuracy in the diagnosis of soft tissue tumors.

• There is a good overall agreement in MR grading between the referring and expert institution.

• In the expert center, there were fewer false-negative and false-positive diagnoses.

• MRI performs better in the tissue-specific diagnosis of benign versus malignant STT.

Compliance and immunogenicity of two hepatitis B vaccination schedules in sex workers in Belgium

OBJECTIVES

To compare the coverage for the third dose and the compliance to two hepatitis B vaccination schedules: 0,1,4 versus 0,1,6 months, in commercial sex workers (CSW) in Belgium; to compare the immunogenicity of the actually administered schedules.

METHODS

In seven health centres in Belgium, hepatitis B vaccination was offered free of charge to CSW. In a randomised, prospective study a commercialised hepatitis B vaccine (Engerix-B 20mcgr) was offered according to one of both schedules. After complete vaccination, bleeding was performed to assess immunogenicity.

RESULTS

Between June 2003 and September 2004, 615 non-immune CSW were enrolled, of whom 52% in the 0,1,4 month schedule (n=322). Coverage of the third dose was 57% overall, 59% (0,1,4) and 54% (0,1,6), respectively. Age, the health centre and drug use significantly influenced the compliance and the coverage of dose 3, whereas the planned vaccination did not. When comparing the immunogenicity results as a function of the actually administered vaccination schedule, immune responses did not significantly differ between CSW receiving the third dose 4-6 months and those receiving it at least 6 months after the first dose. In total, 19 persons (8%) were not protected after a full vaccination course (anti-HBs <10IU/L). Two health centres measured markedly lower anti-HBs levels.

CONCLUSIONS

In this highly mobile at-risk population, a 0,1,4 month schedule is more easy to offer and confers equal protection within a shorter period of time. We therefore propose this 0,1,4 month schedule to vaccinate CSW in the future.

Can we predict uranium bioavailability based on soil parameters? Part 1: effect of soil parameters on soil solution uranium concentration

Present study aims to quantify the influence of soil parameters on soil solution uranium concentration for (238)U spiked soils. Eighteen soils collected under pasture were selected such that they covered a wide range for those parameters hypothesised as being potentially important in determining U sorption. Maximum soil solution uranium concentrations were observed at alkaline pH, high inorganic carbon content and low cation exchange capacity, organic matter content, clay content, amorphous Fe and phosphate levels. Except for the significant correlation between the solid-liquid distribution coefficients (K(d), L kg(-1)) and the organic matter content (R(2)=0.70) and amorphous Fe content (R(2)=0.63), there was no single soil parameter significantly explaining the soil solution uranium concentration (which varied 100-fold). Above pH=6, log(K(d)) was linearly related with pH [log(K(d))=-1.18 pH+10.8, R(2)=0.65]. Multiple linear regression analysis did result in improved predictions of the soil solution uranium concentration but the model was complex.

Can we predict uranium bioavailability based on soil parameters? Part 2: soil solution uranium concentration is not a good bioavailability index

The present study aimed to quantify the influence of soil parameters on uranium uptake by ryegrass. Ryegrass was established on eighteen distinct soils, spiked with (238)U. Uranium soil-to-plant transfer factors (TF) ranged from 0.0003 to 0.0340kgkg(-1). There was no significant relation between the U soil-to-plant transfer (or total U uptake or flux) and the uranium concentration in the soil solution or any other soil factor measured, nor with the U recovered following selective soil extractions. Multiple linear regression analysis resulted in a significant though complex model explaining up to 99% of variation in TF. The influence of uranium speciation on uranium uptake observed was featured: UO(2)(+2), uranyl carbonate complexes and UO(2)PO(4)(-) seem the U species being preferentially taken up by the roots and transferred to the shoots. Improved correlations were obtained when relating the uranium TF with the summed soil solution concentrations of mentioned uranium species.

Male sex workers in Antwerp, Belgium: a descriptive study

The objective of this study was to describe the prevalence of sexually transmitted infections (STI), sociodemographic and behavioural characteristics in a population of male sex workers (MSW) in Antwerp, Belgium. Between September 1999 and March 2004, 129 MSW were reached by Gh@pro, an outreach programme providing preventive health care, free STI check-up and hepatitis B vaccination, to sex workers (SW). Sera were collected from 121 men, urine samples from 115 men and a questionnaire was filled in by 43 MSW. In 45.5% of MSW one or more STI were diagnosed (including hepatitis B), 76% on laboratory testing at first screening, 9% through symptomatology at first visit. The prevalence of HIV was 10.8%, hepatitis B virus (HBV) infection 28.9%, syphilis 12.5%, gonorrhoea 1.7% and Chlamydia trachomatis 9.7%. More than 50% of non-immune MSW completed their three-dose hepatitis B vaccination course. Prevalence of STI is concordant with published data on MSW; this population clearly requests and deserves particular attention and approach. There is an important difference in sociodemographic and behavioural characteristics between MSW working in the red light district and those working on the street. Health promotion should be tailored to the different subpopulations and outreach appears to be a successful tool.

Parity-induced changes in global gene expression in the human mammary gland

The protective effect of an early first full-term pregnancy in relation to breast cancer risk is well established, but the molecular and cell-specific changes in the human mammary gland involved remain unclear. To identify the molecular changes associated with pregnancy-induced differentiation, we analysed the global gene expression profiles of normal mammary tissues from both a parous and a nulliparous woman, using serial analysis of gene expression. This approach allowed us to identify sets of genes, known and unknown, that are differentially expressed in parous versus age-matched nulliparous mammary gland tissues. The normal mammary gland of a multiparous woman is characterized by several known differentiation markers such as casein kappa, casein beta, keratin 14, CCAAT/enhancer binding protein beta and delta and adipsin. Candidate genes involved in cytoarchitectural remodelling and growth inhibition with a potential role in pregnancy-induced protection against breast cancer were also observed. Several genes that are highly expressed in the nulliparous mammary gland and that are lost after pregnancy, encode for growth promoting, cytoskeletal and extracellular matrix proteins. One of these genes, the small breast epithelial mucin, is almost completely downregulated upon a first full-term pregnancy but is known to be expressed in more than 90% of invasive ductal carcinomas.