cPRA Increases With DQA, DPA, and DPB Unacceptable Antigens in the Canadian cPRA Calculator

A calculated panel reactive antibody (cPRA) estimates the percentage of donors with unacceptable antigens (UA) for a recipient. cPRA may be underestimated in transplant candidates with UA to DQA, DPA, and DPB if these are not included in the calculation program. To serve the National Canadian Transplant Programs, a cPRA calculator was developed with complete molecular typing for all donors at HLA-A, B, C, DRB1, DRB3/4/5, DQA1, DQB1, DPA1, and DPB1, all resolved to serologic equivalents. The prevalence of UA at DQA, DPA and DPB was evaluated in a sensitized regional population. The impact of adding these additional UA to cPRA was calculated alone and in combination, and compared to the baseline cPRA for UA at A, B, C, DR, DR51/52/53, and DQ. Of 740 sensitized transplant candidates, 18% of total and 32% with cPRA≥95% had DQA UA. Twenty-seven percent of total and 54% with cPRA≥95% had DPB UA. Of 280/740 subjects with these UA, 36/280 (13%) had cPRA increase of >20% when they were included, 7% increased cPRA to ≥80% and 6% to ≥95%. Inclusion of DQA, DPA, and DPB UA in Canadian cPRA calculations improves the accuracy of cPRA where these are relevant in allocation.

In sickness and in health: A cross-sectional analysis of concordance for musculoskeletal pain in 13,507 couples

Background

Musculoskeletal pain conditions are common and create substantial burden for the individual and society. While research has shown concordance between couples for risk of some diseases, e.g. heart disease or diabetes, little information is available on such effects for musculoskeletal pain conditions. Our aims were to investigate the presence of concordance between couples for consultations about pain, and to examine theoretical influences on such concordance.

Methods

This was a 1‐year cross‐sectional study of musculoskeletal pain consultations in a UK primary care database. In total 27,014 patients (13,507 couples) aged between 30 and 74 years were included. The main outcome measure was the presence of a musculoskeletal morbidity read code indicating a consultation for musculoskeletal conditions (any, back, neck, knee, shoulder, foot, osteoarthritis). Logistic regression was used to test associations with odds ratios (OR) and 95% confidence intervals (95% CI).

Results

Patients whose partner had a musculoskeletal pain consultation were also more likely to consult for a musculoskeletal condition (OR 1.22, 95% CI 1.12–1.32). This association was found to be strongest for shoulder disorders (OR 1.91, 95% CI 1.06–3.47). No significant associations were found for other pain conditions.

Conclusion

Results show that partner concordance is present for consultations for some musculoskeletal conditions but not others. Possible explanations for concordance include the shared health behaviours between couples leading to potential heightened awareness of symptoms. Given the high prevalence of musculoskeletal pain within populations, it may be worth considering further the mechanisms that explain partner concordance.

Controlling the reproducibility of Coulomb blockade phenomena for gold nanoparticles on an organic monolayer/silicon system

Two types of highly ordered organic layers were prepared on silicon modified with an amine termination for binding gold nanoparticles (AuNPs). These two grafted organic monolayers (GOMs), consisting of alkyl chains with seven or 11 carbon atoms, were grafted on oxide-free Si(111) surfaces as tunnel barriers between the silicon electrode and the AuNPs. Three kinds of colloidal AuNPs were prepared by reducing HAuCl4 with three different reactants: citrate (Turkevich synthesis, diameter ∼16 nm), ascorbic acid (diameter ∼9 nm), or NaBH4 (Natan synthesis, diameter ∼7 nm). Scanning tunnel spectroscopy (STS) was performed in a UHV STM at 40 K, and Coulomb blockade behaviour was observed. The reproducibility of the Coulomb behavior was analysed as a function of several chemical and physical parameters: size, crystallinity of the AuNPs, influence of surrounding surfactant molecules, and quality of the GOM/Si interface (degree of oxidation after the full processing). Samples were characterized with scanning tunneling microscope, STS, atomic force microscope, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy (XPS), and high resolution transmission electronic microscope. We show that the reproducibility in observing Coulomb behavior can be as high as ∼80% with the Natan synthesis of AuNPs and GOMs with short alkyl chains.

Whole-exome sequencing improves mutation detection in a diagnostic epidermolysis bullosa laboratory

BACKGROUND

Subtypes of inherited epidermolysis bullosa (EB) vary significantly in their clinical presentation and prognosis. Establishing an accurate diagnosis is important for genetic counselling and patient management. Current approaches in EB diagnostics involve skin biopsy for immunohistochemistry and transmission electron microscopy, and Sanger sequencing of candidate genes. Although informative in most cases, this approach can be expensive and laborious and may fail to identify pathogenic mutations in ~15% of cases.

OBJECTIVES

Next-generation DNA sequencing (NGS) technologies offer a fast and efficient complementary diagnostic strategy, but the value of NGS in EB diagnostics has yet to be explored. The aim of this study was to undertake whole-exome sequencing (WES) in nine cases of EB in which established diagnostic methods failed to make a genetic diagnosis.

METHODS

Whole-exome capture was performed using genomic DNA from each case of EB, followed by massively parallel sequencing. Resulting reads were mapped to the human genome reference hg19. Potentially pathogenic mutations were subsequently confirmed by Sanger sequencing.

RESULTS

Analysis of WES data disclosed biallelic pathogenic mutations in each case, with all mutations occurring in known EB genes (LAMB3, PLEC, FERMT1 and COL7A1). This study demonstrates that NGS can improve diagnostic sensitivity in EB compared with current laboratory practice.

CONCLUSIONS

With appropriate diagnostic platforms and bioinformatics support, WES is likely to increase mutation detection in cases of EB and improve EB diagnostic services, although skin biopsy remains an important diagnostic investigation in current clinical practice.

The AURORA initiative for metastatic breast cancer

Metastatic breast cancer is one of the leading causes of cancer-related mortality among women in the Western world. To date most research efforts have focused on the molecular analysis of the primary tumour to dissect the genotypes of the disease. However, accumulating evidence supports a molecular evolution of breast cancer during its life cycle, with metastatic lesions acquiring new molecular aberrations. Recognising this critical gap of knowledge, the Breast International Group is launching AURORA, a large, multinational, collaborative metastatic breast cancer molecular screening programme. Approximately 1300 patients with metastatic breast cancer who have received no more than one line of systemic treatment for advanced disease will, after giving informed consent, donate archived primary tumour tissue, as well as will donate tissue collected prospectively from the biopsy of metastatic lesions and blood. Both tumour tissue types, together with a blood sample, will then be subjected to next generation sequencing for a panel of cancer-related genes. The patients will be treated at the discretion of their treating physicians per standard local practice, and they will be followed for clinical outcome for 10 years. Alternatively, depending on the molecular profiles found, patients will be directed to innovative clinical trials assessing molecularly targeted agents. Samples of outlier patients considered as 'exceptional responders' or as 'rapid progressors' based on the clinical follow-up will be subjected to deeper molecular characterisation in order to identify new prognostic and predictive biomarkers. AURORA, through its innovative design, will shed light onto some of the unknown areas of metastatic breast cancer, helping to improve the clinical outcome of breast cancer patients.

Abstract 1172: Targeting c-Met and VEGFR2 in the stromal compartment of prostate cancer bone metastasis

Advanced-stage prostate cancer patients commonly develop bone metastasis, accounting for significant morbidity and mortality. Metastatic prostate cancer cells characteristically induce osteoblastic reactions, for which no targeted therapies are currently available. Recent clinical and experimental data showed that dual inhibition of c-Met and VEGF receptor (VEGFR)-2 kinase activity reduced prostate cancer growth in bone with indications for suppressing osteoblastic activities, while the specific functions of c-Met and VEGFR2 in osteoblasts remain unclear. In our in vitro studies using three types of osteoblasts (MC3T3-E1 subclone 4, hFOB1.19 and murine calvarial osteoblasts), hepatocyte growth factor (HGF, a ligand for c-Met) and VEGFA increased expression of receptor activator of nuclear factor κB ligand (RANKL) and macrophage colony stimulating factor (M-CSF), two essential factors for osteoclastogenesis. In addition, siRNA-mediated knockdown of c-Met or VEGFR2 in osteoblasts suppressed HGF- or VEGFA-dependent gene expression, respectively. We demonstrate that insulin growth factor (IGF) increased RANKL and M-CSF expression in osteoblasts via c-Met transactivation. Furthermore, the conditioned media from IGF-, HGF-, or VEGFA-treated osteoblasts promoted in vitro osteoclastogenesis that was suppressed by inhibition of c-Met and VEGFR2 in osteoblasts. Subsequently, we examined whether cabozantinib, a dual kinase inhibitor of c-Met and VEGFR2 currently in clinical trials for metastatic prostate cancer, could suppress prostate cancer bone metastasis via inhibition of osteoblasts. To examine the effects of cabozantinib specifically in osteoblasts, cabozantinib-resistant PC-3 prostate cancer cells were generated and implanted in the tibiae of male nude mice. Cabozantinib (60mg/kg) or control diluent was administered via daily oral gavage for 3 weeks. In agreement with our in vitro data, cabozantinib suppressed tumor growth in bone (determined by in vivo bioluminescence) and tumor-induced osteolysis (determined by X-ray). Tumor cells were isolated and in vitro cultured to demonstrate that cabozantinib resistance was maintained during 3-week in vivo growth. Osteoblasts and osteoclasts numbers were reduced in the bones of cabozantinib-treated mice, and these histological changes were accompanied by significantly lower levels of RANKL and M-CSF levels in bone. Collectively, inhibition of c-Met and VEGFR2 in osteoblasts reduces RANKL and M-CSF expression, associated with decreased osteoclastogenesis and tumor-induced osteolysis. Therefore, we conclude that c-Met and VEGFR2 are promising therapeutic targets in the stromal compartment of prostate cancer bone metastasis, suggesting hat the effects of cabozantinib on skeletal-related events of prostate cancer are, at least in part, mediated by suppression of osteoblast function.

Citation Format: Changki Lee, Preston Campbell, Young Mi Whang, Jamey D. Young, Florent Elefteriou, Serk In Park. Targeting c-Met and VEGFR2 in the stromal compartment of prostate cancer bone metastasis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1172. doi:10.1158/1538-7445.AM2014-1172

Abstract 5326: COSMIC: Enhancing the world's knowledge of somatic mutations in human cancer

COSMIC, the Catalogue Of Somatic Mutations In Cancer (http://cancer.sanger.ac.uk) is the world's largest and most comprehensive online resource for exploring the impact of somatic mutations in human cancer. Now running for over 10 years, the 67th release (Oct 2013) describes 1592109 mutations in 947213 tumour samples across 25606 genes. This information is curated manually from the scientific literature, and automatically from genome resequencing consortium data portals. Full curation of the scientific literature provides in-depth understanding of the impact that each gene has in human cancer, and this has been achieved for 127 point-mutated cancer genes, and 185 fusion gene pairs. Curated genes are selected from the Cancer Gene Census (http://cancer.sanger.ac.uk/census), a listing of all genes with substantial evidence implicating them in cancer promotion, currently numbering 513 and updated frequently.

The mutations discovered in the re-sequencing of over 8000 tumour genomes are now present in COSMIC (viewable in isolation from the genic curations, http://cancer.sanger.ac.uk/wgs). In addition, the Sanger has now fully exome sequenced 1015 common cancer cell lines, identifying 1146874 coding mutations annotated for functional significance, and this is available exclusively in COSMIC at (http://cancer.sanger.ac.uk/cell_lines). While COSMIC has focused on point mutations and gene fusions, many other mutation mechanisms cause oncogenesis and these are now being integrated. The 67th COSMIC release includes copy number mutations integrated into the database and major web page views. To allow easy graphical examination of this data, copy number information was reduced to ‘gain’ and ‘loss’ annotations for inclusion in histograms and tables, with much more precise detail available with a further click. Copy number data is available in detail for every gene in COSMIC, and also for every tissue. Exploring cancer via COSMIC’s Cancer Browser (http://cancer.sanger.ac.uk/cosmic/browse/tissue), results not just in a plot of the most mutated genes, but now also a circular genome plot summarizing the copy number gains and losses across all the samples from that tumour type, all explorable in more detail via clicks on the pictures.

As the genomic data increases in COSMIC, it is becoming more important to qualitatively annotate the information, indicating which is more important or significant to oncogenesis. We are now building systems to better highlight known or putative functional mutations, improving the signal-to-noise ratio of cancer genome resequencing.

Citation Format: C Boutselakis, S A. Forbes, P Gunasekaran, M Jia, D Beare, N Bindal, C Y. Kok, K Leung, D Minjie, R Shepherd, S Bamford, S Ward, C Cole, J W. Teague, M Stratton, P Campbell, U McDermott. COSMIC: Enhancing the world's knowledge of somatic mutations in human cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5326. doi:10.1158/1538-7445.AM2014-5326

Using genetic profiles of African forest elephants to infer population structure, movements, and habitat use in a conservation and development landscape in Gabon

Conservation of wide-ranging species, such as the African forest elephant (Loxodonta cyclotis), depends on fully protected areas and multiple-use areas (MUA) that provide habitat connectivity. In the Gamba Complex of Protected Areas in Gabon, which includes 2 national parks separated by a MUA containing energy and forestry concessions, we studied forest elephants to evaluate the importance of the MUA to wide-ranging species. We extracted DNA from elephant dung samples and used genetic information to identify over 500 individuals in the MUA and the parks. We then examined patterns of nuclear microsatellites and mitochondrial control-region sequences to infer population structure, movement patterns, and habitat use by age and sex. Population structure was weak but significant, and differentiation was more pronounced during the wet season. Within the MUA, males were more strongly associated with open habitats, such as wetlands and savannas, than females during the dry season. Many of the movements detected within and between seasons involved the wetlands and bordering lagoons. Our results suggest that the MUA provides year-round habitat for some elephants and additional habitat for others whose primary range is in the parks. With the continuing loss of roadless wilderness areas in Central Africa, well-managed MUAs will likely be important to the conservation of wide-ranging species.

Control of bone remodeling by the peripheral sympathetic nervous system

The skeleton is no longer seen as a static, isolated, and mostly structural organ. Over the last two decades, a more complete picture of the multiple functions of the skeleton has emerged, and its interactions with a growing number of apparently unrelated organs have become evident. The skeleton not only reacts to mechanical loading and inflammatory, hormonal, and mineral challenges, but also acts of its own accord by secreting factors controlling the function of other tissues, including the kidney and possibly the pancreas and gonads. It is thus becoming widely recognized that it is by nature an endocrine organ, in addition to a structural organ and site of mineral storage and hematopoiesis. Consequently and by definition, bone homeostasis must be tightly regulated and integrated with the biology of other organs to maintain whole body homeostasis, and data uncovering the involvement of the central nervous system (CNS) in the control of bone remodeling support this concept. The sympathetic nervous system (SNS) represents one of the main links between the CNS and the skeleton, based on a number of anatomic, pharmacologic, and genetic studies focused on β-adrenergic receptor (βAR) signaling in bone cells. The goal of this report was to review the data supporting the role of the SNS and βAR signaling in the regulation of skeletal homeostasis.

European multidisciplinary consensus statement on the use and monitoring of metal-on-metal bearings for total hip replacement and hip resurfacing

INTRODUCTION

There is an ongoing debate about the optimal use of metal-on-metal (MoM) bearings in total hip replacement, since there are uncertainties about local and systemic adverse effects due to wear and corrosion of these bearings. Despite various national recommendations, efforts to achieve international harmonization of specific evidence-based recommendations for best practice are still lacking.

HYPOTHESIS

An international consensus study group should be able to develop recommendations on the use and monitoring of MoM bearings, preferably at the European level, through a multidisciplinary approach, by integrating the perspectives of various stakeholders.

MATERIALS AND METHODS

Twenty-one experts representing three stakeholder groups and eight countries participated in this European consensus study, which consisted of a consensus meeting, subsequent structured discussion, and consensus voting.

RESULTS

The current statement defines first of all benefits, local and systemic risks, as well as uncertain issues related to MoM bearings. Safety assessment after implantation of MoM comprises all patients. A closer follow-up is recommended for large head MoM (≥36mm) and resurfacing. In these implants basic follow-up should consist of x-rays and metal ion measurement of cobalt in whole blood, performed with GF-AAS or ICP-MS. Clinical and/or radiographic abnormality as well as elevated ion levels needs additional imaging (ultrasound, CT-scan and/or MARS-MRI). Cobalt values less than 2 μg/L are probably devoid of clinical concern, the threshold value for clinical concern is expected to be within the range of 2-7 μg/L.

DISCUSSION

This is the first multinational, interdisciplinary, and multiprofessional approach for developing a recommendation for the use and monitoring of MoM bearings in total hip replacement. The current recommendations are in partial agreement with previous statements regarding the extent of follow-up and imaging techniques. They however differ from previous communications regarding measurement of metal ions and especially the investigated medium, technique, and eventual threshold levels.

LEVEL OF EVIDENCE

Level V, expert opinion/agreement conference.

Randomized controlled trial of high-dose intradermal versus standard-dose intramuscular influenza vaccine in organ transplant recipients

The immunogenicity of standard intramuscular (IM) influenza vaccine is suboptimal in transplant recipients. Also, recent studies suggest that alloantibody may be upregulated due to vaccination. We evaluated a novel high-dose intradermal (ID) vaccine strategy. In conjunction, we assessed alloimmunity. Transplant recipients were randomized to receive IM or high-dose ID vaccine. Strain-specific serology and HLA alloantibody production was determined pre- and postimmunization. In 212 evaluable patients (105 IM, 107 ID), seroprotection to H1N1, H3N2 and B strains was 70.5%, 63.8% and 52.4% in the IM group, and 71.0%, 70.1%, 63.6% in the ID group (p=ns). Seroconversion to ≥1 antigen was 46.7% and 51.4% in the IM and ID groups respectively (p=0.49). Response was more likely in those≥6 months posttransplant (53.2% vs. 19.2%; p=0.001). Use of mycophenolate mofetil was inversely associated with vaccine response in a dose-dependent manner (p<0.001). Certain organ subgroups had higher response rates for influenza B in the ID vaccine group. Differences in anti-HLA antibody production were detected in only 3/212(1.4%) patients with no clinical consequences. High-dose intradermal vaccine is an alternative to standard vaccine and has potential enhanced immunogenicity in certain subgroups. In this large cohort, we also show that seasonal influenza does not result in significant alloantibody production.

Precision diagnostics in transplantation: from bench to bedside

The Canadian and American Societies of Transplantation held a symposium on February 22, 2012 in Quebec City focused on discovery, validation and translation of new diagnostic tools into clinical transplantation. The symposium focused on antibody testing, transplantation pathology, molecular diagnostics and laboratory support for the incompatible patient. There is an unmet need for more precise diagnostic approaches in transplantation. Significant potential for increasing the diagnostic precision in transplantation was recognized through the integration of conventional histopathology, molecular technologies and sensitive antibody testing into one enhanced diagnostic system.