Kirshner J, MacDonald D, Thurston G, C. Lin H, J. Murphy A, Zhang W. In-silico discovery of cancer-specific peptide-HLA complexes for targeted therapy

BACKGROUND

Major Histocompatibility Complex (MHC) or Human Leukocyte Antigen (HLA) Class I molecules bind to peptide fragments of proteins degraded inside the cell and display them on the cell surface. We are interested in peptide-HLA complexes involving peptides that are derived from proteins specifically expressed in cancer cells. Such complexes have been shown to provide an effective means of precisely targeting cancer cells by engineered T-cells and antibodies, which would be an improvement over current chemotherapeutic agents that indiscriminately kill proliferating cells. An important concern with the targeting of peptide-HLA complexes is off-target toxicity that could occur due to the presence of complexes similar to the target complex in cells from essential, normal tissues.

RESULTS

We developed a novel computational strategy for identifying potential peptide-HLA cancer targets and evaluating the likelihood of off-target toxicity associated with these targets. Our strategy combines sequence-based and structure-based approaches in a unique way to predict potential off-targets. The focus of our work is on the complexes involving the most frequent HLA class I allele HLA-A*02:01. Using our strategy, we predicted the off-target toxicity observed in past clinical trials. We employed it to perform a first-ever comprehensive exploration of the human peptidome to identify cancer-specific targets utilizing gene expression data from TCGA (The Cancer Genome Atlas) and GTEx (Gene Tissue Expression), and structural data from PDB (Protein Data Bank). We have thus identified a list of 627 peptide-HLA complexes across various TCGA cancer types.

CONCLUSION

Peptide-HLA complexes identified using our novel strategy could enable discovery of cancer-specific targets for engineered T-cells or antibody based therapy with minimal off-target toxicity.

Abstract 1484: Combined treatment with anti-LAG-3 and anti-PD-1 fully human monoclonal antibodies inhibits tumor growth in immunocompetent double-humanized LAG-3/PD-1 mice

Lymphocyte-activation gene 3 (LAG-3) receptor is expressed on activated CD4 and CD8 T cells, γδ T cells, Treg, NK, NKT, B and plasmacytoid dendritic cells. LAG-3 binds to major histocompatibility complex class II (MHC II) and delivers inhibitory signals that regulate T cell proliferation and cytokine production. LAG-3 blockade augments T cell proliferation and activation. Programmed cell death 1 (PD-1) receptor upon binding to its ligands PD-L1 (B7-H1; CD274) and PD-L2 (B7-DC; CD273) also delivers an inhibitory checkpoint signal that is critical for the establishment and maintenance of peripheral T cell tolerance. PD-1 signaling plays a critical role in the tumor microenvironment by allowing tumors to escape immune surveillance.

We tested in vivo activity of anti-mouse PD-1 and anti-mouse LAG-3 antibodies in several preclinical syngeneic tumor models and showed that combination treatment with both antibodies resulted in an additive anti-tumor effect compared to either single antibody treatment. TaqMan analysis in the MC38 tumor model demonstrated CD8+ T cell expansion in both the draining lymph nodes and spleens of mice in the combination treatment group.

Anti-human LAG-3 antibody is a fully human monoclonal antibody developed for cancer immunotherapy. It binds with high affinity to human LAG-3 and blocks LAG-3/MHC II interaction. Fully human monoclonal antibody REGN2810 binds with high affinity to human PD-1 and blocks PD-1 interaction with PD-L1 and PD-L2.

Double humanized LAG-3/PD-1 mice were engineered using VelociGene® technology to replace the extracellular domains of mouse Pdcd1 and Lag3 genes with the corresponding regions of human PD-1 and human LAG-3 genes. To validate humanized protein expression, we examined PD-1 and LAG-3 protein expression on T cells after anti-CD3/anti-CD28 antibody stimulation. We confirmed binding of human LAG-3 and PD-1 to the corresponding mouse ligands by cell adhesion assay for human LAG-3 and mouse MHC II interactions and by SPR-Biacore for human PD-1 and mouse PD-L1 interactions, respectively.

Combination of REGN2810 and anti-hLAG-3 antibodies in MC38.ova tumor model in double humanized LAG-3/PD-1 mice, which allows testing of clinical antibodies that do not cross to mouse receptors, demonstrated improved efficacy, including reduced tumor growth and improved survival, compared to REGN2810 and anti-hLAG-3 monotherapies.

Robust anti-tumor efficacy of REGN2810 and anti-hLAG-3 combination in preclinical setting supports their clinical development as a combination cancer immunotherapy.

Citation Format: Elena Burova, Omaira Allbritton, Chandrika Taduriyasas, Venus Lai, William Poueymirou, Nicholas Papadopoulos, Douglas MacDonald, William Olson, Markus Mohrs, Ella Ioffe, Gavin Thurston. Combined treatment with anti-LAG-3 and anti-PD-1 fully human monoclonal antibodies inhibits tumor growth in immunocompetent double-humanized LAG-3/PD-1 mice. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1484.

Metallic hemiarthroplasty for the treatment of end-stage hallux rigidus

Aims

To examine the mid-term outcome and cost utility of the BioPro metallic hemiarthroplasty for the treatment of hallux rigidius.

Patients and Methods

We reviewed 97 consecutive BioPro metallic hemiarthroplasties performed in 80 patients for end-stage hallux rigidus, with a minimum follow-up of five years. There were 19 men and 61 women; their mean age was 55 years (22 to 74). No patient was lost to follow-up.

Results

A total of 12 patients (15 first metatarso-phalangeal joints (MTPJs)) required a revision; one for infection, two for osteolysis and 12 for pain. The all cause rate of survival at five years was 85.6% (95% confidence interval (CI) 83.5 to 87.9). Younger age was a significant predictor of revision (odds ratio 1.09, 95% CI 1.02 to 1.17, p = 0.014) on excluding infection and adjusting for confounding variables (Cox regression). Significant improvements were demonstrated at five years in the Manchester Oxford Foot Questionnaire (13.9, 95% CI 10.5 to 17.2) and in the physical component of the Short Form-12 score (6.5, 95% CI 4.1 to 8.9). The overall rate of satisfaction was 75%. The cost per quality adjusted life year at five years, accounting for a 14% rate of revision was between £4431 and £6361 depending on the complexity and morbidity of the patient.

Conclusion

The BioPro hemiarthroplasty offers good short to mid-term functional outcome and is a cost effective intervention. The relatively high revision rate is associated with younger age and perhaps the use of this implant should be limited to older patients. Cite this article: Bone Joint J 2016;98-B:945–51.

A typological characterization of Canadian beef cattle farms based on a producer survey

The diverse nature of beef production was captured by establishing a farm typology based on an extensive survey of 1005 Canadian farms in 2011. The survey provided information on the type of operation, cattle numbers, feed storage and management, manure management, land use, producer demographics and attitudes to risk, and technology adoption. Principal component analysis and cluster analysis were used to understand the relationships among variables and to statistically identify farm types. A total of 41 diagnostic variables from 133 survey questions were used to define 16 principal components explaining 68% of the variation. Cluster analysis yielded eight major clusters as distinct farm types. The largest number of farms (37%) was grouped as small-scale, part-time cow–calf operations. Mixed operations (crop–beef) were next most frequent (22%), followed by large cow–calf backgrounding (18%) and diversified cow–calf operations that included crop–beef mixed operations as well as off-farm activities (11%). Cow–calf operations that finished calves comprised 8% of the total farms surveyed. Extensive cow–calf backgrounding operations, large backgrounding/finishing operations, and large finishing operations represented the remaining 3% of the farms. The typology not only provides a strategy by which the Canadian beef cattle industry can be characterized, but also improves understanding of the diversity of farm management practices to help develop policies and beneficial management practices.

Resistance to Anti-VEGF Therapy Mediated by Autocrine IL6/STAT3 Signaling and Overcome by IL6 Blockade

Anti-VEGF therapies benefit several cancer types, but drug resistance that limits therapeutic response can emerge. We generated cell lines from anti-VEGF-resistant tumor xenografts to investigate the mechanisms by which resistance develops. Of all tumor cells tested, only A431 (A431-V) epidermoid carcinoma cells developed partial resistance to the VEGF inhibitor aflibercept. Compared with the parental tumors, A431-V tumors secreted greater amounts of IL6 and exhibited higher levels of phospho-STAT3. Notably, combined blockade of IL6 receptor (IL6R) and VEGF resulted in enhanced activity against A431-V tumors. Similarly, inhibition of IL6R enhanced the antitumor effects of aflibercept in DU145 prostate tumor cells that displays high endogenous IL6R activity. In addition, post hoc stratification of data obtained from a clinical trial investigating aflibercept efficacy in ovarian cancer showed poorer survival in patients with high levels of circulating IL6. These results suggest that the activation of the IL6/STAT3 pathway in tumor cells may provide a survival advantage during anti-VEGF treatment, suggesting its utility as a source of response biomarkers and as a therapeutic target to heighten efficacious results. Cancer Res; 76(8); 2327-39. ©2016 AACR.

Patrick-Patel R, MacDonald D, Breusch SJ. Total hip replacement: increasing femoral offset improves functional outcome

INTRODUCTION

The aim of this study was to assess the independent effect of radiographic measures of implant position, relative to pre-operative anatomical assessment, on the functional outcome of total hip arthroplasty according to change in the Oxford hip score (OHS) 1 year post surgery.

METHODS

A prospective cohort study was preformed to assess whether improvement in functional outcome (change in OHS at 1 year) and the relationship with femoral offset and length, and acetabular offset and height. After a power calculation 359 patients were recruited to the study and radiographic measures were performed by blinded observers. Regression analysis was used to assess the independent effect of the four radiographic measurements after adjusting for confounding variables.

RESULTS

There was a significant (p < 0.001) decrease in acetabular offset [5.3 mm, 95 % confidence interval (CI) 4.4-6.2] and increase in femoral offset (6.1 mm, 95 % CI 5.4-6.8). Hence there was no significant change in overall offset. Femoral offset was the only radiographic measure to be achieved statistical significance (r = 0.198, 95 % CI 0.063-0.333, p = 0.004) in relation to clinical outcome, with increasing offset being associated with a greater improvement in the OHS. On combining femoral and acetabular offset increasing offset was associated with a greater improvement in the OHS (r = 0.10, 95 % CI 0.01-0.19, p = 0.04).

CONCLUSION

This study supports the long-held biomechanical theory of medialisation of the acetabular component with compensatory increased femoral offset results in improved functional outcome.

Greenhouse gas emissions of Canadian beef production in 1981 as compared with 2011

The present study compared the greenhouse gas (GHG) emissions, and breeding herd and land requirements of Canadian beef production in 1981 and 2011. In the analysis, temporal and regional differences in feed types, feeding systems, cattle categories, average daily gains and carcass weights were considered. Emissions were estimated using life-cycle assessment (cradle to farm gate), based primarily on Holos, a Canadian whole-farm emissions model. In 2011, beef production in Canada required only 71% of the breeding herd (i.e. cows, bulls, calves and replacement heifers) and 76% of the land needed to produce the same amount of liveweight for slaughter as in 1981. Compared with 1981, in 2011 the same amount of slaughter weight was produced, with a 14% decline in CH4 emissions, 15% decline in N2O emissions and a 12% decline in CO2 emissions from fossil fuel use. Enteric CH4 production accounted for 73% of total GHG emissions in both years. The estimated intensity of GHG emissions per kilogram of liveweight that left the farm was 14.0 kg CO2 equivalents for 1981 and 12.0 kg CO2 equivalents for 2011, a decline of 14%. A significant reduction in GHG intensity over the past three decades occurred as a result of increased average daily gain and slaughter weight, improved reproductive efficiency, reduced time to slaughter, increased crop yields and a shift towards high-grain diets that enabled cattle to be marketed at an earlier age. Future studies are necessary to examine the impact of beef production on other sustainability metrics, including water use, air quality, biodiversity and provision of ecosystems services.

Abstract A131: Rapid constitutive internalization and degradation of prolactin receptor (PRLR) is associated with potent cell killing by PRLR antibody drug conjugates (ADC)

Ado-trastuzumab-emtansine or T-DM1, an antibody drug conjugate (ADC) targeting the well-characterized breast cancer oncogene HER2, has shown benefit for breast cancer patients. However, treatment is not indicated for patients whose tumors express low or intermediate levels of HER2. Thus, additional targets for ADC are needed in breast cancer. The lineage-restricted marker prolactin receptor (PRLR) is also expressed in a subset of breast cancers. Unexpectedly, we found that, unlike HER2, low levels of cell-surface PRLR are sufficient to mediate efficient ADC killing of breast ductal carcinoma cells, including T47D. To understand what properties of PRLR vs HER2 allow for efficient cell killing, we compared intracellular trafficking of these two receptors. We found that approximately 90% of a PRLR antibody was internalized by T47D cells within 1h after treatment, and the internalized PRLR Ab co-localized with the lysosomal marker, Lysotracker Red. In contrast, trastuzumab was restricted to the plasma membrane and did not co-localize with Lysotracker Red. Overnight incubation of T47D cells with PRLR Ab, but not trastuzumab, resulted in accumulation in a late lysosomal compartment, as detected using the pH-sensitive marker, pHrodo. Inhibiting protein synthesis with cycloheximide resulted in almost complete degradation of PRLR after 2h, whereas HER2 was degraded only slightly after 4h. The rapid turnover of PRLR was not significantly affected by adding exogenous ligand (prolactin), or by PRLR antibodies, or by proteasome inhibitors, but was blocked by lysosomal inhibitors including bafilomycin A1, and monensin. The signals for this constitutive PRLR internalization and degradation appear to be contained within its cytoplasmic domain, since substitution of the PRLR extracellular domain by that of HER2 still resulted in degradation rates similar to those of full length PRLR. Moreover, simultaneous substitution of two dileucine lysosomal sorting signals contained in the PRLR cytoplasmic domain (e.g. 283LL and 292LL) to alanine significantly diminished constitutive PRLR turnover. In accordance with these data, PRLR ADC, but not T-DM1, induced cell cycle arrest (proportional to PRLR ADC-induced cell killing) in T47D cells, which was completely abolished by lysosomal inhibitors. Taken together, these data indicate that rapid constitutive ligand-independent turnover of PRLR, but not Her2, can deliver high amounts of ADC to lysosomes, resulting in efficient tumor cell killing.

Citation Format: Julian Andreev, NIthya Thambi, Frank Delfino, Joel Martin, Marcus P. Kelly, Jessica R. Kirshner, Douglas MacDonald, Nicholas Popadopoulos, Willian Olson, Gavin Thurston. Rapid constitutive internalization and degradation of prolactin receptor (PRLR) is associated with potent cell killing by PRLR antibody drug conjugates (ADC). [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A131.

An open-label expanded-access trial of bendamustine in patients with rituximab-refractory indolent non-Hodgkin lymphoma or previously untreated chronic lymphocytic leukemia: BEND-ACT

BACKGROUND

Bendamustine is a bifunctional alkylating agent with unique properties that distinguish it from other agents in its class. Bendamustine is used as monotherapy or in combination with other agents to treat patients with non-Hodgkin lymphoma (nhl) and chronic lymphocytic leukemia (cll).

METHODS

The prospective interventional open-label bend-act trial evaluated bendamustine in patients with rituximab-refractory indolent nhl (inhl) and previously untreated cll. Study objectives were to assess the safety and tolerability of bendamustine monotherapy and to provide patients with access to bendamustine before Health Canada approval. The study aimed to enrol up to 100 patients. All patients with inhl received an intravenous dose of bendamustine 120 mg/m(2) over 60 minutes on days 1 and 2 for up to eight 21- or 28-day treatment cycles. All patients with cll received an intravenous dose of bendamustine 100 mg/m(2) over 30 minutes on days 1 and 2 for up to six 28-day treatment cycles.

RESULTS

Of 90 patients treated on study (16 with cll and 74 with inhl), 35 completed the study (4 with cll and 31 with inhl). The most common treatment-emergent adverse events (teaes) were nausea (70%), fatigue (57%), vomiting (40%), and diarrhea (33%)-mostly grades 1 and 2. Ondansetron was the most common supportive medication used in the patients (63.5% of those with inhl and 68.8% of those with cll). Neutropenia (32%), anemia (23%), and thrombocytopenia (21%) were the most frequent hematologic teaes, with neutropenia being the most common grade 3 or 4 teae leading to dose modification. Dose delays occurred in 28 patients (31.3%) because of grade 3 or 4 teaes, with a higher incidence of dose delays being observed in inhl patients on the 21-day treatment cycle than in those on the 28-day treatment cycle (50.0% vs. 24.1%). During the study, 33 patients (36.7%) experienced at least 1 serious adverse event, and 4 deaths were reported (all in patients with inhl).

CONCLUSIONS

The type and frequency of the teaes reported accorded with observations in earlier clinical trials and post-marketing experiences, thus confirming the acceptable and manageable safety profile of bendamustine.

Abstract 1088: Exploration of the human peptidome for cancer-specific peptide-MHC targets

Introduction

MHC class-I molecules display peptide fragments of intracellular proteins on the cell surface. Peptide-MHC (pMHC) complexes containing peptide fragments derived from antigenic proteins lead to a T-cell mediated immune response. We are interested in cancer-specific pMHC complexes that are targetable by therapeutic molecules, e.g., bispecific antibodies. A significant concern is off-target toxicity of the therapeutic molecules due to pMHC complexes similar to the target complex in essential, normal tissues. Thus we performed a comprehensive exploration of the 9-mer human intracellular peptidome to computationally identify potential breast cancer-specific pMHC class I targets and evaluate the likelihood of cross-reactivity.

Methods

Our method has four steps: 1. We first identified amino acid sequences of all intracellular proteins and 9-mers from a human protein database (UniprotKB). 2. Next, we use a computational program to predict binding affinities and half-lives of all possible combinations of 9-mers and 13 HLA-A and HLA-B alleles encompassing major HLA supertypes; combinations passing affinity and half-life criteria are classified as potential complexes. 3. For each potential pMHC complex, we identify potential similar complexes; two complexes are considered similar if they have the same HLA allele and 5 or more identical amino acids at identical positions. 4. We classify a complex as a potential target if combined mRNA expression of the complex, and similar complexes is higher in breast cancer tissues (TCGA data) compared to normal essential tissues (GTEx data) in at least 5% of the cancer samples.

Results

We extracted all intracellular protein sequences available in the UniprotKB, from which all 9-mer peptides were derived. Hundreds of thousands of potential pMHC complexes using binding predictions for 13 HLA A and B alleles were identified. For each potential MHC binding peptide, similar amino acid sequences were identified. Combined mRNA expression analysis resulted in the discovery of potential targets, which we further prioritized on the basis of likelihood of off-target effects and breast cancer expression levels of the peptide's gene(s) of origin. While we identified several thousand potential breast cancer specific targets, the number of targets with low likelihood of cross-reactivity is incredibly small.

Conclusions

We have developed a method to identify potential cancer-specific pMHC complexes and to predict potential off-targets of the drugs targeting them, which is essential to the development of safe drugs. Using this method, we examined the landscape of potential breast cancer specific targets derived from the human peptidome. Our examination showed that finding targets with low likelihood of cross-reactivity may be extremely difficult. Nonetheless, our method could help in prioritizing pMHC targets based on the evaluation of the potential cross-reactivity risk.

Citation Format: Ankur Dhanik, Wen Zhang, Jessica Kirshner, Douglas MacDonald, Susan Croll, Calvin Lin, Gavin Thurston, Andrew Murphy. Exploration of the human peptidome for cancer-specific peptide-MHC targets. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1088. doi:10.1158/1538-7445.AM2015-1088

Abstract 1378: Evasive resistance to VEGF blockade mediated by autocrine IL-6/STAT3 signaling in xenograft models of human cancer

Blockade of the VEGF pathway and subsequent inhibition of tumor angiogenesis has been shown to prolong the survival of patients with certain types of solid tumors. However, the extent and duration of the survival benefit is often limited by emergence of resistance. To date, mechanisms of resistance and relevant biomarkers have not been clearly defined. To study mechanisms of anti-VEGF resistance, we used the VEGF inhibitor ziv-aflibercept (also known as VEGF Trap) and derived a resistant tumor line from sensitive A431 human squamous cell carcinomas. A431 tumor cells were implanted subcutaneously into the flank of CB17 SCID mice. When tumors reached approximately 100 -150 mm3, animals were continuously (up to 7 weeks) treated with ziv-aflibercept. Initially, A431 tumors were very responsive to ziv-aflibercept, but resistant outgrowth was observed at 6-7 weeks post treatment start. Outgrowing tumors were harvested, in vivo passaged in the presence of ziv-aflibercept and cell lines were isolated from these resistant tumor variants (A431-V) as well as from in vivo passaged control treated tumors (A431-P). Inherent resistance of A431-V tumors to ziv-aflibercept was confirmed. Using several screening approaches, such as PathScan RTK Signaling Antibody Array, isotope-labeled mass spectrometry and ELISA based assays, the IL-6/STAT3 pathway was identified as one of the most up-regulated signaling pathways in the resistant A431-V model compared to sensitive A431-P cells. IL-6-dependent STAT3 activation was confirmed using the IL-6 receptor blocking antibody sarilumab, which dramatically reduced the constitutive phosphorylation of STAT3 in A431-V cells and tumors. To determine if IL-6 plays a role in anti-VEGF resistance, we assessed the effects of ziv-aflibercept alone or in combination with sarilumab in established subcutaneous A431-V tumors. A431-V tumor resistance to VEGF blockade was abrogated by inhibition of IL-6 signaling; compared to control-treated tumors, combination treatment resulted in 91% tumor growth inhibition 14 days post treatment start, while single agent ziv-aflibercept treatment resulted in 57% tumor growth inhibition. These findings were corroborated in Du145 human prostate tumors with high levels of endogenous IL-6/STAT3 signaling. Combined VEGF and IL-6 blockade showed enhanced anti-tumor activity in DU145 tumor bearing mice compared to single agents. Thus, blockade of the IL-6/STAT3 pathway warrants further investigation in overcoming resistance to anti-VEGF therapy. These data underscore that advanced knowledge of predictive biomarkers as well as resistance mechanisms is crucial for successful patient and treatment selection.

Citation Format: Alexander P. Adler, Alexandra Eichten, Li Zhang, Jia Su, Ella Ioffe, George D. Yancopoulus, Douglas MacDonald, Christopher Daly, Xunbao Duan, Gavin Thurston. Evasive resistance to VEGF blockade mediated by autocrine IL-6/STAT3 signaling in xenograft models of human cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1378. doi:10.1158/1538-7445.AM2015-1378

Beef cattle husbandry practices across Ecoregions of Canada in 2011

Sheppard, S. C., Bittman, S., Donohoe, G., Flaten, D., Wittenberg, K. M., Small, J. A., Berthiaume, R., McAllister, T. A., Beauchemin, K. A., McKinnon, J., Amiro, B. D., MacDonald, D., Mattos, F. and Ominski, K. H. 2015. Beef cattle husbandry practices across Ecoregions of Canada in 2011. Can. J. Anim. Sci. 95: 305–321. Beef production in Canada is diverse in many dimensions with numbers of cattle per operation ranging over 10 000-fold, pasture usage from nil to 100%, and types of operations from solely cow–calf to exclusively feedlot finishing. This study summarizes management information obtained from a survey conducted in 2012 (about 2011) on 1009 beef operations in Canada. Many of the results clearly differentiate the practices in the Prairies from those in Ontario and Quebec. Compared to eastern Canada, the Prairies had earlier and shorter calving seasons, higher weaning weights, utilized more winter grazing with a variety of strategies, grew and fed more barley than corn, used more seasonal feeding areas and feedlots (and hence fewer barns), and more commonly spread manure in the fall. Many of the management practices used by cow–calf operations would have low environmental impact, including extensive use of grazing even in winter, low fertilizer inputs and feeding perennial forages with a high content of legumes. Some practices such as not covering forages or manure storage structures were common and could be changed to improve forage quality and reduce manure emissions. Most forage was harvested 3–7 d after full bloom. Earlier harvest has the potential to improve forage quality, which could reduce dependence on arable crops. Finishing operations used more housing, fed more arable-land crops and less perennial forages, and practiced little grazing. Rationale regarding the adoption of many of the management strategies was reported by the producers. For example, winter grazing was adopted primarily to reduce costs and labour, but for some it was also linked to a late calving season. Preferred sources of technical information included their own experience, farm print media, producer organisations and demonstrations at field days. The survey also identified several areas in which the industry may realize improved sustainability.

Mega prosthetic distal femoral arthroplasty for non-tumour indications: does the indication affect the functional outcome and survivorship?

PURPOSE

To report the functional outcome, implant survival, and patient mortality after mega prosthetic distal femoral arthroplasty according to the surgical indication.

METHODS

A prospective database was compiled for 45 consecutive patients undergoing distal femoral arthroplasty, of which 26 had fractures of the distal femur (group 1) and 19 underwent revision of a total knee arthroplasty (group 2). There were 17 males and 28 females with a median age of 74.5 years. Short form (SF)-12 scores were recorded pre-operatively (before the fracture or revision) and 1 year post-operatively, at which point a Toronto Extremity Salvage Score (TESS) was also obtained. Length of hospital stay and return to place of domicile was obtained from the hospital database. Mortality status was obtained from the General Register Office for Scotland. No patient was lost to follow-up.

RESULTS

The 1-year physical (52.4) and mental (63.4) components of the SF-12 score and the TESS (70.5 %) did not significantly differ between the groups (n.s.). The fracture group, however, had a longer length of stay (8 vs. 19 days, p = 0.001) and were also less likely to return to their original domicile (odds ratio 9.5, p = 0.02). The overall implant survival rate was 85 % at 5 years, which was worse for the fracture group (80 vs. 90 %, n.s.). The 5-year mortality rate for the revision group was 17 %, whereas the fracture group demonstrated a greater mortality rate of 43 % (n.s.).

CONCLUSION

The functional outcome, revision rate, and mortality of patients undergoing distal femoral arthroplasty for non-tumour reasons are not influenced by indication, but patients undergoing surgery for fractures of the distal femur have a longer length of stay and are less likely to return home. Distal femoral arthroplasty should be considered as a management option for non-tumour salvage procedures of the distal femur.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Islet autoantibody status in a multi-ethnic UK clinic cohort of children presenting with diabetes

OBJECTIVE

We prospectively determined islet autoantibody status in children presenting with diabetes to a single UK region in relation to ethnicity.

DESIGN

316 (68.0% non-white) children presenting with diabetes between 2006 and 2013 were tested centrally for islet cell autoantibodies (ICA) and glutamic acid decarboxylase autoantibodies (GAD-65) at diagnosis, and if negative for both, tested for insulin autoantibodies (IAA). The assay used to measure GAD-65 autoantibodies changed from an in-house to a standardised ELISA method during the study.

RESULTS

Even with use of the standardised ELISA method, 25.8% of children assigned a diagnosis of type 1 diabetes still tested negative for all three autoantibodies. 30% of children assigned a diagnosis of type 2 diabetes were autoantibody positive, and these had the highest glycated haemoglobin (HbA1c) levels at 12 months follow-up compared with other groups (p value for analysis of variance <0.001), although the sample size was small. Autoantibody positivity was similar between non-white and white children regardless of assay used (60.0% (n=129) vs 56.4% (n=57), χ(2)=0.9, p=0.35), as was mean GAD-65 autoantibody levels, but fewer non-white children had two or more autoantibodies detectable (13% (n=28) vs 27.7% (n=28), χ(2)=12.1, p=0.001).

CONCLUSIONS

Islet autoantibody positivity was associated with a more severe phenotype, as demonstrated by poorer glycaemic control, regardless of assigned diabetes subtype. Positivity did not differ by ethnic group.

The minimal clinically important difference in the Oxford knee score and Short Form 12 score after total knee arthroplasty

PURPOSE

The aim of this study was to identify the minimal clinically important difference (MCID) in the Oxford knee score (OKS) and Short Form (SF-) 12 score after total knee arthroplasty (TKA).

METHODS

Prospective pre-operative and 1 year post-operative OKS and SF-12 scores for 505 patients undergoing a primary TKA for osteoarthritis were collected during a one-year period. Patient satisfaction with their (1) patient relief and (2) functional outcome was used as the anchor questions. Their response to each question was recorded using a 5-point Likert scale: excellent, very well, well, fair, and poor. Simple linear regression was used to calculate the MCID for improvement in the OKS and physical component of the SF-12 score according to the level of patient satisfaction with their pain relief and function.

RESULTS

The OKS improved by 15.5 (95 % CI 14.7-16.4) points and the SF-12 physical component score improved by 10.1 (95 % CI 9.1-11.2) points for the study cohort. The level of patient satisfaction with their pain relief and function correlated with the improvement in the OKS (r = 0.56; p < 0.001, and r = 0.56; p < 0.001) and the physical component of the SF-12 score (r = 0.51; p < 0.001, and r = 0.60; p < 0.001), respectively. The MCID for the OKS was 5.0 (95 % CI 4.4-5.5) and 4.3 (95 % CI 3.8-4.8) points and for the physical component of the SF-12, it was 4.5 (95 % CI 3.9-5.2) and 4.8 (95 % CI 4.2-5.4) points for pain relief and function, respectively.

CONCLUSION

The MCID identified for the OKS and SF-12 physical component score after TKA is the best available estimate and can be used to power studies and ensure that a statistical difference is also recognised by a patient.

Total knee replacement in patients with concomitant back pain results in a worse functional outcome and a lower rate of satisfaction

This study assessed the effect of concomitant back pain on the Oxford knee score (OKS), Short-Form (SF)-12 and patient satisfaction after total knee replacement (TKR). It involved a prospectively compiled database of demographics and outcome scores for 2392 patients undergoing primary TKR, of whom 829 patients (35%) reported back pain. Compared with those patients without back pain, those with back pain were more likely to be female (odds ratio (OR) 1.5 (95% confidence interval (CI) 1.3 to 1.8)), have a greater level of comorbidity, a worse pre-operative OKS (2.3 points (95% CI 1.7 to 3.0)) and worse SF-12 physical (2.0 points (95% CI 1.4 to 2.6)) and mental (3.3 points (95% CI 2.3 to 4.3)) components.

One year post-operatively, those with back pain had significantly worse outcome scores than those without with a mean difference in the OKS of 5 points (95% CI 3.8 to 5.4), in the SF-12 physical component of 6 points (95% CI 5.4 to 7.1) and in the mental component of 4 points (95% CI 3.1 to 4.9). Patients with back pain were less likely to be satisfied (OR 0.62, 95% CI 0.5 to 0.78).

After adjusting for confounding variables, concomitant back pain was an independent predictor of a worse post-operative OKS, and of dissatisfaction. Clinicians should be aware that patients suffering concomitant back pain pre-operatively are at an increased risk of being dissatisfied post-operatively.

Cite this article: Bone Joint J 2013;95-B:1632–9.

Diabetes does not influence the early outcome of total knee replacement: a prospective study assessing the Oxford knee score, short form 12, and patient satisfaction

BACKGROUND

There is conflicting evidence as to whether diabetes mellitus influences the functional outcome and patient satisfaction after a total knee replacement (TKR). The aim of this study was to assess the effect of diabetes upon the Oxford knee score (OKS), short form (SF)-12, and patient satisfaction after TKR.

METHODS

Prospective pre- and post-operative (one year) OKS and SF-12 scores for 2389 patients undergoing primary TKR were compiled, of which 275 (12%) patients suffered with diabetes. Patient satisfaction was assessed at one year.

RESULTS

Patients with diabetes were more likely to have a greater level of comorbidity (p<0.001), and a worse pre-operative OKS and SF-12 score (p<0.02), compared to those patients without diabetes. Diabetes was not a significant (p>0.41) independent predictor of post-operative OKS or the SF-12 physical score on multivariable analysis. Although, factors more prevalent within the diabetic cohort (heart disease, vascular disease, liver disease, anaemia, depression, back pain, worse pre-operative OKS and SF-12 score) were found to be independent predictors of post-operative OKS and SF-12 physical score. Interestingly, diabetes was associated with a significantly greater improvement in mental wellbeing (SF-12 mental component), which was confirmed on multivariable analysis. Patient satisfaction was not influenced by a concomitant diagnosis of diabetes (p=0.57).

CONCLUSION

The outcome of TKR as assessed by the OKS, SF-12, and overall patient satisfaction rates are not influenced by diabetes per se, although factors more prevalent within this population result in a worse post-operative outcome.

LEVEL OF EVIDENCE

prospective cohort study, level III.

A review of cricket Fielding requirements

Cricket is played in three formats at elite level: Test, One Day and Twenty20. Fielding is an important component of cricket, as all players are obliged to field. However, there is a paucity of literature on fielding compared with that on batting and bowling. We review the available literature in terms of technical, mental, physiological and physical factors important to fielding, to identify knowledge gaps and better understand the performance requirements of fielding in cricket.

A review of cricket Fielding requirements

Cricket is played in three formats at elite level: Test, One Day and Twenty20. Fielding is an important component of cricket, as all players are obliged to field. However, there is a paucity of literature on fielding compared with that on batting and bowling. We review the available literature in terms of technical, mental, physiological and physical factors important to fielding, to identify knowledge gaps and better understand the performance requirements of fielding in cricket.

Primary total knee replacement in patients with mental disability improves their mental health and knee function: a prospective study

We assessed the effect of mental disability on the outcome of total knee replacement (TKR) and investigated whether mental health improves post-operatively. Outcome data were prospectively recorded over a three-year period for 962 patients undergoing primary TKR for osteoarthritis. Pre-operative and one year Short-Form (SF)-12 scores and Oxford knee scores (OKS) were obtained. The mental component of the SF-12 was stratified into four groups according to level of mental disability (none ≥ 50, mild 40 to 49, moderate 30 to 39, severe < 30). Patients with any degree of mental disability had a significantly greater subjective physical disability according to the SF-12 (p = 0.06) and OKS (p < 0.001). The improvement in the disease-specific score (OKS) was not affected by a patient's mental health (p = 0.33). In contrast, patients with mental disability had less of an improvement in their global physical health (SF-12) (p < 0.001). However, patients with any degree of mental disability had a significant improvement in their mental health post-operatively (p < 0.001). Despite a similar improvement in their disease-specific scores and improvement in their mental health, patients with mental disability were significantly more likely to be dissatisfied with their TKR at one year (p = 0.001). Patients with poor mental health do benefit from improvements in their mental health and knee function after TKR, but also have a higher rate of dissatisfaction.