Pre-implantation Testing Research Articles

Genome sequencing of human in vitro fertilisation embryos for pathogenic variation screening

Whole-genome sequencing of preimplantation human embryos to detect and screen for genetic diseases is a technically challenging extension to preconception screening. Combining preconception genetic screening with preimplantation testing of human embryos facilitates the detection of de novo mutations and self-validates transmitted variant detection in both the reproductive couple and the embryo’s samples. Here we describe a trio testing workflow that involves whole-genome sequencing of amplified DNA from biopsied embryo trophectoderm cells and genomic DNA from both parents. Variant prediction software and annotation databases were used to assess variants of unknown significance and previously not described de novo variants in five single-gene preimplantation genetic testing couples and eleven of their embryos. Pathogenic variation, tandem repeat, copy number and structural variations were examined against variant calls for compound heterozygosity and predicted disease status was ascertained. Multiple trio testing showed complete concordance with known variants ascertained by single-nucleotide polymorphism array and uncovered de novo and transmitted pathogenic variants. This pilot study describes a method of whole-genome sequencing and analysis for embryo selection in high-risk couples to prevent early life fatal genetic conditions that adversely affect the quality of life of the individual and families.

The impact of age beyond ploidy: outcome data from 8175 euploid single embryo transfers.

The rate of embryonic aneuploidy increases with increasing female age and is the primary cause of lower pregnancy and live birth rates (LBR) in older reproductive age women. This retrospective cohort study evaluates single euploid embryo transfers to determine whether an age-related decline in reproductive efficiency persists. A total of 8175 non-donor single embryo transfers (SET) after pre-implantation testing for aneuploidy (PGT-A) and cryopreservation were included. These were divided into five groups by patient age: < 35years old (n = 3789 embryos transferred), 35-37 (n = 2200), 38-40 (n = 1624), 41-42 (n = 319), and > 42 (n = 243). Implantation rate (IR), clinical pregnancy rate (CPR), and LBR were calculated for each group as a percentage of embryos transferred and compared. CPR was also analyzed as a percentage of implanted pregnancies, and LBR as a percentage of clinical pregnancies, to determine when age has the greatest impact. These results were then adjusted for confounding variables via a multivariate logistic regression model. Implantation rates negatively correlated with age. After adjusting for confounders, women 38years or older had a significantly lower IR than those under 35 (OR 0.85, 95%CI 0.73-0.99 for 38-40years old; 0.69, 0.53-0.91 for 41-42, and 0.69, 0.51-0.94 for > 42). These differences are also apparent in CPR and LBR. The rates of progression to clinical pregnancy and live birth did not differ significantly by age group. Other factors observed to affect IR independently were anti-Müllerian hormone (AMH), day of embryo transfer, and embryo morphology. While selection of euploid embryos may be effective in overcoming a significant proportion of the age-related decline in reproductive efficiency, a decrease in IR, CPR, and LBR persists even when analyzing only euploid embryo transfers. The observed impact of aging is, therefore, independent of ploidy, as well as of other variables that affect reproductive efficiency. These results indicate that factors other than aneuploidy contribute to reproductive senescence.

Преимплантационное тестирование эмбрионов методом высокопроизводительного секвенирования у супружеских пар с транслокациями в кариотипе

Преимплантационное тестирование эмбрионов методом высокопроизводительного секвенирования у супружеских пар с транслокациями в кариотипе

Utility of Patch Testing and Lymphocyte Transformation Testing in the Evaluation of Metal Allergy in Patients with Orthopedic Implants.

Total joint arthroplasties are increasingly common orthopedic procedures performed throughout the United States. Implant failure after these procedures occurs due to a number of causes such as infection or mechanical problems, with metal hypersensitivity being an area of growing interest. The nature and mechanism of a causative relationship between metal hypersensitivity and implant failure have been unclear as it is not known whether implant failure occurs due to a previous metal allergy or metal allergy results from secondary sensitization via metal exposure in existing failing implants. Overall, there appears to be growing support and evidence for metal-hypersensitive patients having worse outcomes with regard to total hip and knee arthroplasties. However, there are conflicting recommendations (outside of Nuss procedures) for pre-implant testing for metal hypersensitivity as testing has not consistently been shown to change patient outcomes.

55. EFFICACY OF NUCLEAR TRANSFER TO PREVENT THE INHERITED MITOCHONDRIAL PATHOLOGY

Introduction Mitochondrial pathology is characterized by maternal inheritance. Women may be hidden mutation carriers, but in some cases the risk for descendants may reach up to 100%. Due to the uneven distribution of mitochondria during cell division, the practice of preimplantation testing of embryos has significant limitations, and prenatal diagnosis may be unacceptable. The first baby after nuclear transfer procedures was born in 2016 (J. Zhang et al., 2017). Material and methods The study included a married couple with a confirmed hidden woman's carriage of Leigh syndrome mutation (37 years old). The couple had a history of birth of a girl with Leigh syndrome. For ethical reasons, prenatal diagnosis and donation of oocytes were not considered for further childbirth. The patient's mutation carrier status has been confirmed in independent laboratories (mtDNA 9176 T>C, Heteroplasmy ∼ 40%). The child was diagnosed with confirmed Leigh syndrome (Homoplasmy 99.4%). The couple had 2 controlled ovarian stimulations followed by nuclear transfer procedures. Embryo biopsy was performed on Days 5-6 of development. Preimplantation genetic embryo testing PGT-A (NGS: Veriseq, Illumina) and heteroplasmy testing of pathological mutation (NGS, coverage of >1000x) were performed. Rresults During the first stimulation, 3 blastocysts (euploid female embryo and two aneuploid embryos) were obtained. After consultation with the patients, it was decided not to use the female embryo for the embryo transfer. During the second stimulation, 6 blastocysts, incl. 3 aneuploid and 3 euploid (males) were obtained. Heteroplasmy of euploid embryos for pathological mutations: 0.51 ± 0.02%, 2.96 ± 0.05 and 3.32 ± 0.06%. The embryos obtained during ART from a patient with a mtDNA mutation carrier status were characterized by a low level of heteroplasmy of mtDNA mutation and had a low risk of mitochondrial pathology development. The patient is preparing for embryo transfer. Conclusions Nuclear transfer procedures showed high efficiency in describes case. But it is still experimental and highly controversial procedure. Further investigations and long term follow up of children is required.

Results of preimplantation genetic testing for aneuploidies as a basis for parental karyotypes correction

Introduction Chromosomal abnormalities are the most common genetic cause of infertility. An information about karyotypes of patients undergoing in vitro fertilization (IVF) is not always known. Therefore, IVF patients can be potential carriers of structural chromosomal rearrangements. We report three cases, in which results of preimplantation genetic testing for aneuploidies (PGT-A) allowed us to suspect the presence of parental reciprocal translocations. In each case, the parental reciprocal translocation was confirmed. Material & Methods PGT-A was performed by microarray comparative genomic hybridization (aCGH) (24sure, Illumina) or by next generation sequencing (NGS) (VeriSeq, Illumina). Indications for preimplantation testing were advanced maternal age (case 1 and 2) and paternal pericentric inversion of chromosome 10 (case 3). Parental karyotypes were not known before PGT-A in cases 1 and 2. In case 3 patients’ karyotypes was known before PGT-A and were 46,XX and 46,XY,inv(10)(p11.2;q22). The trophectoderm biopsy was performed at 5-6 day of embryo development. Analysis of parental karyotypes after obtaining PGT results was performed by standard cytogenetic study or by fluorescence in situ hybridization (FISH) on peripheral blood lymphocyte culture. The choice of method of parental karyotypes analysis was determined by size of the embryo chromosomal imbalance. Results PGT-A results showed a nonrandom pattern of segmental loses and gains in each case (table 1). These facts were the basis for parental karyotypes analysis. It was confirmed, that in each case one of the couple was the carrier of reciprocal translocation. In case 1 a paternal reciprocal translocation between chromosomes 11 and 22 was found – 46,XY,t(11;22)(q23.3;q13). In case 2 a maternal reciprocal translocation between chromosomes 10 and 12 was found – ish t(10;12)(D10S2290-, D12S158+; D10S2290+, D12S158-). In case 3 a maternal reciprocal translocation between chromosomes 2 and 12 was found - ish t(2;12)(D2S2147-,D12S399+; D2S2147+, D12S399-). Table 1 Case № Number of embryos Number of embryos with nonrandom pattern of segmental abnormalities Chromosomes involved in nonrandom segmental abnormalities Case 1 5 3 Chromosomes 11 and 22 Case 2 4 4 Chromosomes 10 and 12 Case 3 4 3 Chromosomes 2 and 12 Conclusions It is very importantto draw attention to pattern of segmental chromosomal abnormalities of embryos. 24-chromosome aneuploidy testing is not only an actual method for detection of embryo chromosomal imbalance, but in some cases also can help to correct parental karyotypes.

Evaluation of the effect of delayed blastulation on genetic status and pregnancy outcome of the vitrified-warmed elective single embryo transfer (eSET)

Introduction Preimplantation testing for aneuploidy (PGT-A) identifies chromosomally normal embryos with the aim to increase IVF success rate. Trophectoderm biopsy is usually performed on day 5 when the embryos are expanded. A proportion of slower growing embryos that have not reached the expanded blastocyst stage on day 5, or slower developing day 5 morulae are frequently found to have developed to blastocyst stage and expanded by the time of day 6, enable trophectoderm biopsy for chromosome analysis. Blastocyst biopsy with PGT-A increased IVF implantation and delivery. It is not known if prolonging culture of euploid embryos impacts their implantation potential. Material & Methods This is a retrospective analysis of 1,071 IVF patients whom underwent a vitrified-thawed ICSI cycle with PGT-A during January 2016 to July 2017. The rates of full chromosome aneuploidy and segmental (> 10 MB) aneuploidy in trophectoderm biopsies were assessed by Next-generation sequencing-based assay (NGS). No results samples were excluded from the analysis. Aneuploidy rates and pregnancy outcome were compared. Statistical analysis was performed by ANOVA and Chi-square to assess the differences. A total of 5,611 embryos were examined. All embryos were laser hatched at cleavage stage and cultured to day 5/6. 4,222 were biopsied on day 5 and 1,389 were biopsied on day 6. Embryonic ploidy status was examined by analyzing respective trophectoderm cells by NGS (VeriSeq, Illumina). IVF outcome in terms of implantation rates and miscarriage rates were compared between 255 day-5 embryos and 60 day-6 embryos transfers in 315 cycles. Results An average number embryo biopsied per cycle was 6. Day 5 biopsies accounted for 75.2%. The overall aneuploidy rate ranges from 35% ( 42). Aneuploidy rates were higher in day 6 in all individual maternal age group ( 42 yrs 64% vs. 78%, p=0.29. Day 5 biopsy embryos had higher implantation rate (65% vs. 47%, p=0.19) and lower miscarriage rate (1% vs. 7%, p=0.05), than day 6 blastocyst. Delayed blastocyst embryos had an increased in aneuploidy risk, however, the euploid were able to fully developed and successfully implanted achieving a 47% implantation in all combined age group. Conclusions A better understanding on the relationship between embryo delayed development stage and endometrial synchronicity may aid to a higher success rate for cycles achieved only transferrable euploid delayed blastocyst.

Extracochlear Stimulation of Electrically Evoked Auditory Brainstem Responses (eABRs) Remains the Preferred Pre-implant Auditory Nerve Function Test in an Assessor-blinded Comparison.

Electrically evoked auditory brainstem responses (eABRs) can be recorded before cochlear implant (CI) surgery to verify auditory nerve function, and is particularly helpful in to assess the function of the auditory nerve in cases of auditory nerve hypoplasia. This is the first study to compare three preimplant eABRs recording techniques: 1) standard extracochlear, 2) novel intracochlear, and 3) conventional intracochlear with the CI. A within-participants design was used where eABRs were sequentially measured during CI surgery using three methods with stimulation from: 1) an extracochlear electrode placed at the round window niche, 2) two different electrodes on a recently developed Intracochlear Test Array (ITA), and 3) two different electrodes on a CI electrode array. New adults implantees (n = 16) were recruited through the Manchester Auditory Implant Centre and eABR measurements were made in theater at the time of CI surgery. All participants met the clinical criteria for cochlear implantation. Only participants with radiologically normal auditory nerves were recruited to the study. All participants were surgically listed for either a MED-EL Synchrony implant or a Cochlear Nucleus Profile implant, per standard practice in the implant centre. Primary outcome measures were: 1) charge (μC) required to elicit a threshold response, and 2) latencies (ms) in the threshold waveforms. Secondary outcome measures were: 1) morphologies of responses at suprathreshold stimulation levels and 2) wave V growth patterns. eABRs were successfully measured from 15 participants. In terms of primary outcome measures, the charge required to elicit a response using the extracochlear electrode (median = 0.075 μC) was approximately six times larger than all other electrodes and the latency of wave V was approximately 0.5 ms longer when using the extracochlear electrode (mean = 5.1 ms). In terms of secondary outcomes, there were some minor quantitative differences in responses between extracochlear and intracochlear stimulation; in particular, ITA responses were highly variable in quality. The ITA responses were rated poor quality in 33% of recordings and in two instances did not allow for data collection. When not disrupted by open circuits, the median ITA response contained one more waveform than the median extracochlear response. In this first study comparing intracochlear and extracochlear stimulation, the results show that both can be used to produce an eABR that is representative of the one elicited by the CI. In the majority of cases, extracochlear stimulation was the preferred approach for preimplant auditory nerve function testing because of consistency, recordings that could be analyzed, and because extracochlear placement of the electrode does not require a cochleostomy to insert an electrode.

Results in Adult Cochlear Implant Recipients With Varied Asymmetric Hearing: A Prospective Longitudinal Study of Speech Recognition, Localization, and Participant Report.

Asymmetric hearing with severe to profound hearing loss (SPHL) in one ear and better hearing in the other requires increased listening effort and is detrimental for understanding speech in noise and sound localization. Although a cochlear implant (CI) is the only treatment that can restore hearing to an ear with SPHL, current candidacy criteria often disallows this option for patients with asymmetric hearing. The present study aimed to evaluate longitudinal performance outcomes in a relatively large group of adults with asymmetric hearing who received a CI in the poor ear. Forty-seven adults with postlingual hearing loss participated. Test materials included objective and subjective measures meant to elucidate communication challenges encountered by those with asymmetric hearing. Test intervals included preimplant and 6 and 12 months postimplant. Preimplant testing was completed in participants' everyday listening condition: bilateral hearing aids (HAs) n = 9, better ear HA n = 29, and no HA n = 9; postimplant, each ear was tested separately and in the bimodal condition. Group mean longitudinal results in the bimodal condition postimplant compared with the preimplant everyday listening condition indicated significantly improved sentence scores at soft levels and in noise, improved localization, and higher ratings of communication function by 6 months postimplant. Group mean, 6-month postimplant results were significantly better in the bimodal condition compared with either ear alone. Audibility and speech recognition for the poor ear alone improved significantly with a CI compared with preimplant. Most participants had clinically meaningful benefit on most measures. Contributory factors reported for traditional CI candidates also impacted results for this population. In general, older participants had poorer bimodal speech recognition in noise and localization abilities than younger participants. Participants with early SPHL onset had better bimodal localization than those with later SPHL onset, and participants with longer SPHL duration had poorer CI alone speech understanding in noise but not in quiet. Better ear pure-tone average (PTA) correlated with all speech recognition measures in the bimodal condition. To understand the impact of better ear hearing on bimodal performance, participants were grouped by better ear PTA: group 1 PTA ≤40 dB HL (n = 19), group 2 PTA = 41 to 55 dB HL (n = 14), and group 3 PTA = 56 to 70 dB HL (n = 14). All groups showed bimodal benefit on speech recognition measures in quiet and in noise; however, only group 3 obtained benefit when noise was toward the CI ear. All groups showed improved localization and ratings of perceived communication. Receiving a CI for the poor ear was an effective treatment for this population. Improved audibility and speech recognition were evident by 6 months postimplant. Improvements in sound localization and self-reports of communication benefit were significant and not related to better ear hearing. Participants with more hearing in the better ear (group 1) showed less bimodal benefit but greater bimodal performance for speech recognition than groups 2 and 3. Test batteries for this population should include quality of life measures, sound localization, and adaptive speech recognition measures with spatially separated noise to capture the hearing loss deficits and treatment benefits reported by this patient population.

Determinants of Improvement in Cardiopulmonary Exercise Testing After Left Ventricular Assist Device Implantation

Although improvement in cardiac output and hemodynamic parameters is routinely demonstrated in patients implanted with continuous-flow left ventricular assist devices (CF-LVADs), improvement in exercise capacity is inconsistently seen. Our purpose was to determine whether native cardiac factors, LVAD factors, or comorbid factors were associated with lack of improvement. Review of all patients undergoing preimplant cardiopulmonary exercise testing (CPET) and CPET on LVAD therapy at one institution was performed between 2007 and 2014 (n = 49). Comprehensive assessment of echocardiographic parameters, right heart catheterization data, medications, and comorbid illness was undertaken. There was no mean improvement in peak oxygen consumption (VO2; 11.8-12.4 ml/kg/min; p = 0.26), although exercise time (5.1 [46% predicted] to 5.8 min [56% predicted]; p = 0.02) and nadir of the ratio of minute ventilation to carbon dioxide production slope (VE/VCO2; 39-36; p = 0.001) improved. Factors most strongly associated with improvement in VO2 were Heartmate II pulsatility index (PI; R = 0.48; p = 0.001), power (R = -0.40; p = 0.009), pump flow (R = -0.40; p = 0.008), and pump speed (R = -0.32; p = 0.04). Peak heart rate (HR) was also associated with improvement in VO2 (R = 0.41; p = 0.004). Left ventricular ejection fraction (LVEF; R = 0.004; p = 0.77), right ventricular (RV) function (R = 0.22; p = 0.28), and aortic valve opening (R = 0.20; p = 0.57) were not associated with improvement in VO2. Our data suggest that less reliance on LVAD support was modestly associated with improvement in exercise capacity. Further studies should seek to determine the optimal level of device support prospectively in relation to exercise capacity.

Reproductive Medicine Involving Mitochondrial DNA Modification: Evolution, Legality, and Ethics

Human oocytes have an abundance of mitochondria that have their own genome. Mitochondrial functions are exerted through evolutionarily-developed interactions between the nucleus and mitochondria. Since 1996, fertility clinics have practiced various types of germline mitochondrial DNA (mtDNA) modification that alter the composition of mtDNA copies in oocytes or zygotes using micromanipulation. Experimental reproductive medicine has primarily intended to treat intractable infertility and has been used to prevent the maternal transmission of a pathogenic mtDNA mutation to offspring. In some cases, it has helped parents have a healthy genetically-related child; in others, it has resulted in miscarriages, aneuploid fetuses, or developmental disorders in the offspring. Adverse events have raised ethical controversy, leading to restrictive or prohibitive policies in the USA and China. Conversely, the UK recently became the first nation to explicitly permit two types of germline mtDNA modification (termed mitochondrial donation) for the sole purpose of preventing serious mitochondrial disease in offspring. The aim of this review is three-fold: first, to reshape the medical concept and evolution of germline mtDNA modification, while revisiting 14 clinical cases. Second, to analyse the legality of mtDNA modification, focussing on 16 Western countries. Finally, to consider the ethical aspects, including permissible cases, reproductive options, use of preimplantation and prenatal testing, and the humane follow-up of resultant children. The clinical use of germline mtDNA modification will likely become legal, at least for use in preventative medicine, in some countries. However, the potential clinical, ethical, and evolutionary implications mean that caution is required when considering its wider application.

Evaluation of preimplantation genetic testing for chromosomal structural rearrangement by a commonly used next generation sequencing workflow

ObjectivesTo evaluate the applicability of a commonly used next generation sequencing workflow in detecting unbalanced meiotic segregation products for reciprocal translocation and inversion carriers. Study designAll preimplantation genetic testing treatment cycles performed for reciprocal translocation or inversion carriers from 2012 to April 2017 were included. Three hundreds and forty-two archived whole genome amplified DNA, which had previously analyzed by array comparative genomic hybridization (aCGH), were retrospectively analyzed by next generation sequencing (NGS). Concordance on overall diagnosis and segmental aneuploidies related to the translocation/inversion breakpoints between aCGH and NGS were determined. ResultsRetrospective analysis of 287 blastomere biopsies and 55 trophectoderm (TE) biopsies showed that the concordance rate on the overall diagnosis between aCGH and NGS on abnormal samples was 100% (266/266), irrespective to the type of biopsy. The concordance rates of normal biopsies were 98.4% (61/62) on blastomere and 78.6% (11/14) on TE biopsies. NGS detected a de novo segmental aneuploidy on one blastomere biopsy and three possible low level mosaic aneuploidies on 3 TE biopsies, which were previously concluded as euploid by aCGH. Using the karyotype of reciprocal translocation/inversion carriers, size of anticipated segmental aneuploidies could be calculated and be used to predict the applicability of NGS before proceeding to treatment. ConclusionThis is the first report to evaluate the applicability of a commercial NGS-based workflow for preimplantation testing for reciprocal translocations/inversions. Our study demonstrated that NGS can diagnose unbalanced translocation/inversion products with the same efficiency as aCGH. The applicability of NGS, with respect to individual karyotype, can be predicted before proceeding to treatment.

Patch Testing for the Evaluation of Metal Hypersensitivity in the Nuss Procedure.

The Nuss procedure has become the predominant reason for the use of metal implants by pediatric general and thoracic surgeons. Current guidelines recommend preimplant testing for all patients undergoing the Nuss procedure, which differs from the guidelines for all other orthopedic procedures. This review was done to further evaluate this discrepancy.

Does the number of trophectoderm cells analyzed by targeted next generation sequencing correlate with the incidence of aneuploid, mosaic or indeterminate results

Trophectoderm cells extruded from the expanding blastocyst provide meaningful genetic information regarding reproductive competence. The number of cells removed at biopsy may be a function of the number of cells present in a dividing blastocyst, and a surrogate marker for embryo quality. We hypothesized that the number of trophectoderm cells identified in a biopsy sample could predict blastocyst quality and that the number of biopsied cells could be a marker of test performance. This study sought to evaluate whether the number of cells obtained at biopsy is correlated with the preimplantation testing (PGT) result.

Transferring embryos with genetic anomalies detected in preimplantation testing: an Ethics Committee Opinion

Patient requests for transfer of embryos with genetic anomalies linked to serious health-affecting disorders detected in preimplantation testing are rare but do exist. This Opinion sets out the possible rationales for a provider's decision to assist or decline to assist in such transfers. The Committee concludes in most clinical cases it is ethically permissible to assist or decline to assist in transferring such embryos. In circumstances in which a child is highly likely to be born with a life-threatening condition that causes severe and early debility with no possibility of reasonable function, provider transfer of such embryos is ethically problematic and highly discouraged.

Metal Hypersensitivity Reactions to Orthopedic Implants.

Total hip and knee replacement surgery using metal alloy devices is common. Type IV allergic reactions to these implants occur, though infrequently. While uncommon, peri-implant metal allergic reactions may cause significant morbidity for the affected individual—including aseptic loosening, pseudotumor formation and frank device failure. It is challenging to predict who will have these reactions, even in those with established pre-implant metal allergy. At this time, the scientific literature clearly supports few conclusions. Despite this, we believe several conclusions can be made: routine pre-implant testing in asymptomatic individuals is not indicated; listen to patient’s concerns about metal allergy if the concern arises; patch testing is probably the best pre- and post-implant screening test; post-implantation testing is controversial and even positive LTT or patch test does not definitively diagnose morbidity from a metal allergy; and complete recovery following revision placement of an immunologically inert device is diagnostic. More research is needed to scientifically approach this issue.

Prosthetic and Device Surgery Considerations

Biomedical implants have a broad array of therapeutic uses, most commonly in orthopedic procedures, such as dynamic hip and knee replacements. There are also wide-ranging applications in cardiology, gynecology, and other specialties. Use of metal components will likely expand with further medical innovations. Hypersensitivity reactions to these devices are well documented but uncommon. Patch testing is currently the best evaluation for metal hypersensitivity reactions (MHR). Preimplant testing for asymptomatic individuals is not necessary. Patients with a history of skin rashes dermatitis after metal contact would likely benefit from preimplant testing. Those individuals with postoperative complications such as aseptic loosening; chronic pain; or new, unexplained local or regional dermatitis may benefit from evaluation for MHR. Metal allergy testing is never indicated in emergent or life-threatening situations. Whether prior to or after implant placement, collaborative efforts between the allergist and surgeon should determine the clinical plan. A positive test for metal allergy should not define treatment. When a metal allergy is revealed prior to implant, every effort should be taken to avoid the allergen(s). Often, titanium or oxidized zirconium alloys are the most appropriate choice for those allergic to stainless steel components. Clinical decision making after implantation is challenging. If the implant is asymptomatic, no action should be taken. Symptomatic patients following implant are more challenging. The surgeon and patient need to determine whether replacement with a non-allergenic alternative is feasible, necessary, and safe. Prospective trials in this field are still necessary to develop a more evolved and evidence-based approach to treatment of patients with MHR.

353 - Improvement in Cardiopulmonary Exercise Testing after LVAD Implant is Associated with Native Cardiac Function

Introduction: Although improved cardiac output and hemodynamic parameters is routinely demonstrated in patients implanted with continuous-flow left ventricular assist devices (CF-LVADs), improvement in exercise capacity is inconsistently seen. Our purpose was to determine whether native cardiac factors, LVAD factors, or comorbid factors were associated with lack of improvement. Methods: Review of all patients undergoing pre-implant cardiopulmonary exercise testing (CPET) as well as CPET on LVAD therapy at one institution was performed between 2007 and 2014 (n = 49). Comprehensive assessment of echocardiographic parameters, right heart catheterization data, medications, and comorbid illness was undertaken. Results: There was no mean improvement in peak oxygen consumption (VO2) (11.8 to 12.4 ml/kg/min, P = .26), though exercise time (5.1 [46% predicted] to 5.8 mins [56% predicted]) and nadir of the ratio of minute ventilation to carbon dioxide production (VE/VCO2) (39 to 36) improved (P = .02 and P = .001, respectively). Factors most significantly associated with improvement in VO2 were HM2 pulsatility index (PI) (R2 = 0.44, P = .003), power (inversely) (R2 = 0.16, P = .009), pump flow (inversely) (R2 = 0.16, P = .008), and RPM (inversely) (R2 = 0.10, P = .04). Neither left ventricular ejection fraction (LVEF) (R2 = 0.003, P = .74) nor change in left ventricular end diastolic diameter (LVEDD) (R2 = 0.003, P = .70) were associated with improvement in VO2. Furthermore, changes in VO2 were not associated with right heart catheterization data, including cardiac output, nor comorbid illnesses. Conclusions: Our data suggest that better native heart function and less reliance on LVAD support were associated with improvement in exercise capacity. Further studies should seek to determine the optimal level of device support prospectively in relation to exercise capacityTabled 1Characteristics on pre- and post-implant testingEXERCISE DATAPre-LVADLVAD-therapyP-valuePeak VO2 (ml/min/BSA)11.8 ± 2.912.4 ± 3.0.26VO2 % predicted43 ± 9.648 ± 13.02Exercise Time (min)5.1 ± 1.45.8 ± 1.9.02METS3.6 ± 1.03.7 ± 1.1.30HR rest (bpm)78 ± 1380 ± 10.31HR peak (bpm)107 ± 17110 ± 21.35HR recovery (bpm)5.1 ± 5.69.0 ± 11.2.03SBP rest (mmHg)101 ± 1697 ± 11.87SBP peak (mmHg)105 ± 1998 ± 12.09RER1.12 ± 0.141.13 ± 0.11.72VE/VCO239.2 ± 6.536.0 ± 6.3.001ECHO DATALVEF (%)21 ± 1024 ± 10.095LVEDD (mm)71.6 ± 10.861.0 ± 12.2<.001LVAD DATAFlow (liter/min)N/A5.1 ± 0.8Power (W)N/A6.1 ± 1.3PIN/A5.1 ± 0.9Analysis of changes in peak VO2 with continuous covariatesDEMOGRAPHIC DATACharacteristic at Time of CPETStrength of association (R2)P-valueBody mass index (kg/m2)28 ± 40.08(-).05Implant IntentionDT (67%), BTT (33%)0.13.01Ischemic vs. Nonischemic41% ischemic0.01.47EXERCISE DATABP peak on Rx (mmHg)98.4<0.001.96Peak HR on Rx (bpm)1120.17.004ECHO DATALVEF on Rx (%)21 ± 100.003.74Aortic valve opening47%0.009.54LVAD DATALVAD RPM (HM2 only)9480 ± 5600.10(-).04LVAD flow (HM2 only)5.1 ± 0.80.16(-).008LVAD power (HM2 only)6.1 ± 1.30.16(-).009PI (HM2 only)5.1 ± 0.90.20.003 Open table in a new tab

Genetic counseling and testing for Huntington's disease: A historical review.

This manuscript describes the ways in which genetic counseling has evolved since John Pearson and Sheldon Reed first promoted "a genetic education" in the 1950s as a voluntary, non-directive clinical tool for permitting individual decision making. It reviews how the emergence of Huntington's disease (HD) registries and patient support organizations, genetic testing, and the discovery of a disease-causing CAG repeat expansion changed the contours of genetic counseling for families with HD. It also reviews the guidelines, outcomes, ethical and laboratory challenges, and uptake of predictive, prenatal, and preimplantation testing, and it casts a vision for how clinicians can better make use of genetic counseling to reach a broader pool of families that may be affected by HD and to ensure that genetic counseling is associated with the best levels of care. © 2016 Wiley Periodicals, Inc.

Should metal alloy discs be used for patch testing in suspected metal implant intolerance reaction?

Intolerance reactions to metal implants may be caused by metal allergy. However, prior to implantation, patch testing should not be done in a prophylactic-prophetic approach. Pre-implant patch testing should only be performed to verify or exclude metal allergy in patients with a reported respective history. In the case of implant-in particular arthroplasty-related complications like, for example, pain, effusion, skin changes, reduced range of motion, or loosening, orthopedic-surgical differential diagnostics should be performed first. Allergological workup of suspected metal implant allergy should be done with the DKG baseline series which contains nickel-, cobalt- and chromium-preparations. Various studies assessing the usefulness of metal alloy discs for patch testing proved that this approach does not give reliable information about metal allergy. Positive patch test reactions to the discs cannot be assigned to a specific metal within the disc alloy components. Furthermore, availability of such metal discs might be an invitation to uncritical testing. Accordingly, due to lack of benefit in comparison to patch testing with standardized metal salt preparations, we do not recommend patch testing with metal alloy discs.