Comparative evaluation of Luminex based assays for detection of SARS-CoV-2 antibodies in a transplantation laboratory

BACKGROUND

Detection of SARS-CoV-2 antibodies is essential in establishing the parameters of an individual's immune response to COVID-19, from both natural infection and vaccination. Despite this, there is currently limited clinical guidance or recommendations for serological methods for their measurement. Here, we evaluate and compare four Luminex-based assays for the multiplex detection of IgG SARS-CoV-2 antibodies.

METHODS

The four assays tested were Magnetic Luminex Assay, MULTICOV-AB Assay, Luminex xMAP SARS-CoV-2 Multi-Antigen IgG Assay and LABScreen COVID Plus Assay. Each assay's ability to detect antibodies to SARS-CoV-2 Spike (S), Nucleocapsid (N) and Spike-Receptor Binding Domain (RBD) was evaluated using 50 test samples (25 positive, 25 negative), previously tested by a widely used ELISA technique.

RESULTS

The MULTICOV-AB Assay had the highest clinical performance detecting antibodies to S trimer and RBD in 100% (n = 25) of known positive samples. Both the Magnetic Luminex Assay and LABScreen COVID Plus Assay showed significant diagnostic accuracy with sensitivities of 90% and 88% respectively. The Luminex xMAP SARS-CoV-2 Multi-Antigen IgG Assay demonstrated limited detection of antibodies to the S antigen resulting in a sensitivity of 68%.

CONCLUSION

Luminex-based assays provide a suitable serological method for multiplex detection of SARS-CoV-2 specific antibodies, with each assay able to detect antibodies to a minimum of 3 different SARS-CoV-2 antigens. Assay comparison identified there is moderate performance variability between manufacturers and further inter-assay variation of antibodies detected to different SARS-CoV-2 antigens.

Treatment by biomarker-informed endotype vs guideline care in children with difficult-to-treat asthma

BACKGROUND

Asthma is heterogeneous, contributing to difficulty in disease management.

OBJECTIVE

To develop a biomarker-informed treatment model for difficult-to-treat (DTT) asthma and conduct a pilot feasibility study.

METHODS

School-aged children (n = 21) with DTT asthma were enrolled and completed 3 medical visits (V1-V3). V2 and V3 were completed approximately 3.5 months and 12 months after V1, respectively. At V1, guideline care and adherence interventions were initiated, and blood samples were collected for asthma biomarker assessment. A personalized treatment algorithm was developed based on biomarkers (treatment by endotype) and was implemented at V2. Asthma outcomes were compared from V1 to V2 (guideline-based care) to V2 to V3 (guideline + biomarker-informed care).

RESULTS

Overall retention was 86%. There was an even distribution of participants with allergy, without allergy, and with mixed allergies. The participants received an average of 5.9 interventions (range, 3-9). The allergic phenotype was characterized by increased CDHR3 risk genotype and high transepidermal water loss. High serum interleukin-6 level was most notable in the mixed allergic subgroup. The nonallergic phenotype was characterized by vitamin D deficiency and poor steroid treatment responsiveness. The personalized treatment plans were associated with decreased emergency department visits (median, 1 vs 0; P = .04) and increased asthma control test scores (median, 22.5 vs 23.0; P = .01).

CONCLUSION

The biomarker-based treatment algorithm triggered interventions on top of guideline care in all children with DTT asthma studied, supporting the need for this type of multipronged approach. Our findings identify the minimal biomarker set that is informative, reveal that this treatment-by-endotype intervention is feasible and may be superior to guideline care alone, and provide a strong foundation for a definitive trial.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04179461.

A252 DO GLIM CRITERIA FOR DIAGNOSING MALNUTRITION AGREE WITH SGA IN HOSPITALIZED PATIENTS RECEIVING TPN?

Background

The Global Leadership Initiative on Malnutrition (GLIM) proposed a new two-step model for diagnosing malnutrition in 2019. A combination of two etiologic and three phenotypic criteria are used to assess malnutrition. The Subjective Global Assessment (SGA) is the most well validated assessment tool for diagnosing malnutrition in hospitalized patients. Evaluation of the performance of GLIM criteria in comparison to SGA is necessary before implementing this new diagnostic tool in practice.

Aims

To compare GLIM criteria to SGA in assessing malnutrition severity in hospitalized patients requiring parenteral nutrition (PN).

Methods

This is a retrospective analysis of a prospectively collected database of malnourished hospitalized adult patients requiring PN admitted between March 2020 and March 2021 to an academic hospital in Winnipeg, Canada. 172 cases were evaluated. GLIM malnutrition screening was considered positive if one etiologic (high CRP or low food intake) and one phenotypic (weight loss or low BMI) criteria were identified. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated and expressed with a Wilson 95% confidence interval.

Results

The prevalence of malnutrition using SGA B or C criteria was 82.3% (CI 73.8, 85.5). Using GLIM criteria, the prevalence of malnutrition was 33.7% (27.1, 41.1). The prevalence of severe malnutrition using SGA C was 32.6% (26.0, 40.0) and using GLIM criteria the prevalence was 19.2% (14.0, 25.7). Using any combination of GLIM criteria versus SGA B or C combined, the PPV was 100% (90.4, 100) and the specificity was 100% (89.9, 100); NPV was 30.0% (22.0, 38.5) and the sensitivity was 42.0% (34.1, 50.4). Using any combination of GLIM criteria versus only SGA C patients, PPV decreased to 72.4% (59.8, 82.3) and specificity was 86.2% (78.8, 91.3); NPV increased to 87.7% (80.4, 92.5) and sensitivity was 75.0% (62.3, 84.5). Comparing severely malnourished patients by GLIM criteria to only SGA C patients, PPV was 97% (84.7, 99.5) and specificity was 99.1% (95.3, 100). NPV was 82.7% (75.6, 88.1) and sensitivity was 57.1% (44.1, 69.2).

Conclusions

Using SGA as the gold standard for diagnosing malnutrition in hospitalized patients requiring PN, GLIM criteria had a very high PPV but unacceptably low NPV in diagnosing malnutrition. The NPV improved when GLIM criteria was compared only to severely malnourished patients by SGA. Importantly, in comparing severely malnourished patients by GLIM and SGA criteria, the sensitivity was also unacceptably low. Based on these results, GLIM criteria are most useful in confirming the diagnosis of malnutrition or severe malnutrition; a negative result should not reassure clinicians that severe malnutrition is absent. Further studies evaluating GLIM criteria are needed before it replaces SGA as a decision making tool.

Funding Agencies

None

Non-invasive monitoring and reintroduction biology of the brush-tailed rock-wallaby (

Thirty-nine endangered brush-tailed rock-wallabies (Petrogale penicillata) were reintroduced to Grampians National Park, western Victoria, between 2008 and 2012. Subsequent high mortality, low breeding, and no recruitment were linked to fox predation and physical disturbance during monitoring. From 2014 to 2017, the colony was left undisturbed and monitored only by remote camera. Five adult animals were identified across this period (1 ♂ and 3 ♀s – all tagged; and one untagged female), and an average of 0.7 pouch young were birthed per tagged female per year. In 2019, camera-monitoring and non-invasive genetic monitoring (faecal) were used to identify colony members, genetic diversity, and breeding. Camera monitoring in 2019 identified the same five individuals, whereas genetic monitoring using 12 microsatellites identified eight individuals (two male and six female genotypes). Genetic diversity within the colony was moderate (expected heterozygosity (He) = 0.655, observed heterozygosity (Ho) = 0.854). Leaving the colony undisturbed after 2013 correlated with improved adult survival, increased breeding, and successful recruitment of young to the population. Recommendations for the Grampians colony include continuation of regular camera- and scat monitoring to improve our understanding of the reintroduction biology of P. penicillata and other marsupials in open, unfenced landscapes.

Duloxetine in OsteoArthritis (DOA) study: effects of duloxetine on pain and function in end-stage hip and knee OA – a pragmatic enriched randomized controlled trial

Background

Some osteoarthritis (OA) patients experience inadequate pain relief from analgesics like acetaminophen and nonsteroidal anti-inflammatory drugs. This could be the result of experienced non-nociceptive centralized pain. Placebo-controlled randomized trials (RCT) have proven the effectiveness of duloxetine for OA and several chronic pain conditions where central sensitization (CS) is one of the key underlying pain mechanisms.

Objectives

Assess the efficacy of an 8-week duloxetine treatment compared to usual care in end-stage knee and hip OA patients with a level of centralized pain.

Design

Pragmatic, enriched, open-label RCT.

Methods

Patients were randomized to duloxetine or to care-as-usual. Primary outcome was pain in the index joint, measured with the pain domain of the Knee injury and Osteoarthritis Outcome Score (KOOS) or the Hip disability and Osteoarthritis Outcome Score (HOOS). The intention-to-treat principle was used, with mixed-model repeated measures to analyze the effect.

Results

One hundred eleven patients were randomized. Nearly 44% felt much to very much better after duloxetine usage compared to 0% in the care-as-usual group (p < 0.001). The duloxetine group scored 11.3 points (95%CI: 5.8, 16.8) better on the pain domain of the KOOS/HOOS (p < 0.001). Knee patients improved significantly more than hip patients (18.7 [95%CI: 11.3, 26.1] versus 6.0 [95%CI: − 2.6, 14.5] points better).

Conclusions

Adding duloxetine treatment seems to be beneficial for end-stage knee OA patients with neuropathic-like symptoms (at risk of CS). End stage Hip OA patients seem to be nonresponsive to duloxetine.

Trial registration

Dutch Trial Registry with number NTR 4744 (15/08/2014) and in the EudraCT database with number 2013–004313-41.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05034-0.

Parker Solar Probe Enters the Magnetically Dominated Solar Corona

The high temperatures and strong magnetic fields of the solar corona form streams of solar wind that expand through the Solar System into interstellar space. At 09:33 UT on 28 April 2021 Parker Solar Probe entered the magnetized atmosphere of the Sun 13 million km above the photosphere, crossing below the Alfvén critical surface for five hours into plasma in casual contact with the Sun with an Alfvén Mach number of 0.79 and magnetic pressure dominating both ion and electron pressure. The spectrum of turbulence below the Alfvén critical surface is reported. Magnetic mapping suggests the region was a steady flow emerging on rapidly expanding coronal magnetic field lines lying above a pseudostreamer. The sub-Alfvénic nature of the flow may be due to suppressed magnetic reconnection at the base of the pseudostreamer, as evidenced by unusually low densities in this region and the magnetic mapping.

Secondary flow in bifurcations - Important effects of curvature, bifurcation angle and stents

Coronary bifurcations have complex flow patterns including secondary flow zones and helical flow, which directly affect pathophysiological mechanisms such as the development of atherosclerosis. The objective of this study was to generate insights into the effects of curvature, bifurcation angle and the presence of stents on flow patterns and resulting haemodynamics in coronary left main bifurcations. The blood flow and associated metrics were modelled in both idealised and patient-specific bifurcations with varying curvature and bifurcation angles with and without stents, resulting in a total of 128 geometries considered. The results showed that larger curvature of bifurcating vessels has a significant influence on secondary flow, especially with distance to the bifurcation region, causing a skew, spin and asymmetry of Dean vortices, an increase in helical flow intensity with symmetry loss, and a decrease in adversely low time-average wall shear stress (TAWSS). Generally, asymmetric flow patterns coincided with adversely low TAWSS regions. In identical stented geometries, the presence of the stents induced local recirculation immediately adjacent to the stent struts, thus generating adversely low TAWSS in these areas, with some effect on the overall secondary flow. Overall, the effect of stents outweighed the effect of curvature and BA. This new knowledge contributes to a better understanding of the joint effects of curvature, bifurcation angle, and stents on flow patterns and haemodynamics in coronary bifurcations.

Shift work amongst older UK workers and job exit

BACKGROUND

Night/shift work may be increasing but there are few data about the prevalence amongst older workers. With governments encouraging people to work to older ages, it is important to know how feasible night/shift work is for them and whether there are any adverse health consequences.

AIMS

Amongst current older workers (aged 50-64 years), to explore the prevalence of night/shift working and evaluate its health impacts and sustainability over 4 years of follow-up.

METHODS

Data from the Health and Employment After Fifty cohort were used to describe the demographic, job and health characteristics of men and women undertaking night/shift work. Longitudinal data were used to examine the number and nature of exits annually thereafter.

RESULTS

Amongst the 5409 working at baseline, 32% reported night/shift work in sectors which differed by sex. Night/shift workers were more likely to be: current smokers; doing physically demanding work; struggling to cope at work; dissatisfied with their hours; depressed; sleeping poorly; rating their health poorly. Women whose job involves night work were more likely to exit the workforce over 4 years.

CONCLUSIONS

Almost one in three contemporary UK older workers report night/shift work. We found some evidence of adverse impacts on health, sleep and well-being and higher rates of job exit amongst women. More research is needed but night/shift work may be challenging to sustain for older workers and could have health consequences.

Recovery Courses of Patients Who Return to Work by 3, 6 or 12 Months After Total Knee Arthroplasty

Purpose This study compared the preoperative levels and postoperative recovery courses of physical and mental impairments, activity limitations and participation restrictions of working-age patients who return to work (RTW) by 3, 6 or 12 months after total knee arthroplasty (TKA). Methods A prospective survey study including TKA patients (aged < 65) (n = 146) who returned to work (RdTW) in the first postoperative year. Three groups were compared: those who returned by 3 (n = 35), 6 (n = 40) or 12 (n = 29) months. Surveys were completed preoperatively and at 6 weeks and 3, 6 and 12 months postoperatively. Outcomes represented domains of the International Classification of Functioning, i.e. physical impairments (pain, stiffness, vitality), mental impairments (mental health and depressive symptoms), activity limitations (physical functioning) and participation restrictions (social and work functioning). Results Preoperative knee-specific pain and physical functioning levels were better among patients who RdTW by 3 months, compared to those who returned by 12 months. Patients who RdTW by 3 months experienced significantly better recovery from physical impairments than those who returned by 6 months (on general pain) or 12 months (on general and knee-specific pain and on stiffness). Patients returning by 3 months experienced significantly better recovery from activity limitations (on knee-specific physical functioning). Conclusions To optimize return to work outcome after TKA surgery, the focus should lie on physical impairments (general and knee-specific pain, stiffness) and activity limitations (knee-specific physical functioning) during recovery.

Accelerometer Measured Sedentary and Physical Activity Behaviors of Working Patients after Total Knee Arthroplasty, and their Compensation Between Occupational and Leisure Time

Purpose Objective measurements of sedentary and physical activity (PA) behavior are scarce among working-age patients who undergo total knee arthroplasty (TKA). Aim was to assess sedentary and PA behaviors using accelerometers and to identify compensation effects between occupational and leisure time of sedentary and PA behavior. Methods One year post-TKA, 51 patients wore an ActiGraph(GT3x) accelerometer for 7 days. Sedentary time, prolonged sedentary bouts (≥ 30 min) and PA (light-intensity and moderate-to-vigorous PA) were examined. Compliance with the guideline of > 150 min moderate-to-vigorous PA per week was calculated. Compensation effects were analyzed using multilevel models, splitting effects into routine and within-day compensation, stratifying by physical and non-physical jobs. The routine compensation effects are the ones of interest, representing habitual compensation during a week. Results Participants spent 60% of time in sedentary bouts and 17% in prolonged sedentary bouts, with 37% of PA spent in light-intensity and 3% in moderate-to-vigorous activity. About 70% of patients met the PA guideline. Routine compensation effects were found for workers in physical jobs, who compensated for their occupational light-intensity PA with less light-intensity PA during leisure time. Workers in non-physical jobs did not compensate for their occupational prolonged sedentary bouts, as these continued during leisure time. Conclusion This study showed that working TKA patients are highly sedentary 1 year after surgery, but most met the PA guideline. Especially those with non-physical jobs do not compensate for their occupational prolonged sedentary bouts. This stresses the need to stimulate PA among TKA patients not complying with the guidelines and those with non-physical jobs.

An experimental evaluation of a concept to improve conventional aortic prostheses

Conventionally used textile prosthesis for traditional open surgical repair (OSR) of aortic aneurysms have a lower compliance than the native aortic tissue. Graft placements lead to an acute drop in compliance which effects cardiovascular risk and the development of graft related complications. A custom-made spring casing was applied to a Dacron graft segment under physiological pressure conditions within a five-element biventricular mock circulation loop, to investigate experimentally a concept to improve the compliance of a conventional aortic prosthesis by changing the transverse graft cross-section. Two different prosthesis locations, proximal and distal of compliant silicone tubing were used to study uniaxial graft compression with an elastic device. To characterise the devices' performance by means of pulse pressure (PP), diastolic pressure (P_dia) and pulse wave velocity(PWV), fluid pressures and flow were recorded. In a proximal graft setting (ascending aorta repair) elastic uniaxial compression with a custom-made spring casing (2 cm width) could significantly reduce PP by 10-14% (p < .001) and slowed PWV from 6.7 to 5.2 m/s (22%, p = .002). Applied to a graft in a distal position, the spring casing demonstrated less impact on PP (2-10%), but significantly reduced PWV in this mock aorta segment from 13.7 to 5.5 m/s (60%, p = .004). In conclusion, a newly conceptualised spring casing applied to the external wall of synthetic aortic grafts can reduce PP and slow PWV. By restoring elastic aortic recoil in stiff textile aortic prostheses, the presented concept is a potential solution to improve long-term aortic prosthesis related complications.

AB1078 USE OF MYOSITIS SPECIFIC AUTOANTIBODIES TEST ACROSS A LARGE NHS HOSPITAL TRUST

Background:

The immunology laboratory at Barts Health supports a large clinical myopathy service, providing blood tests for myositis-specific autoantibodies (MSA) by a commercial line immunoblot panel for Jo1, PL7, PL12, SRP, Mi2, Ku, PM-Scl and Scl-70.

As Idiopathic Inflammatory Myositis (IIM) disease subtype definitions have evolved from the 1975 Bohan & Peter criteria, the discovery of new antibodies has proven useful in the hands of neuromuscular clinicians whose patients have a high pre-test probability of disease. Ready availability of the test has led to increased demand from:

Objectives:

Determine the frequency of MSA requests from different departments.

To investigate the possibility of rejecting requests for MSAs at the laboratory in the absence of an elevated creatine kinase (CK), a hallmark of muscle damage associated with myositis (1).

Methods:

MSA were measured by a commercial line blot (Bluediver) which included Jo-1, PL-7, PL-12, Mi-2, Ku, SRP-54 and PM-Scl-100. Demographics and results for all MSA requested between September 2017 and November 2019 were pulled from laboratory records, together with CK results (if performed). CK was interpreted as low, normal or elevated according to reference ranges of 25-200 U/L (female) or 40-320 U/L (male).

Results:

597 tests were performed between 2017 and 2019. In total 59/597 (10%) were positive for the audited antibodies (Table 1). General Practitioner (GP) requests accounted for 41/597 (6.9%) tests, internal 464/597 (78%) and external 82/597 (14%). External requests were the most frequently positive at 10/82 (12%), internal requests 46/464 (10%), and GP requests only 3/41 (7%) of the time. Of all internal requesting sources, Respiratory accounted for the largest number at 108/597 (18%), followed by neurology with 85/597 (14%) (Figure 1). GPs constituted the 4thlargest source of requests.

Table 1.Positive on polymyositis screen% positivityAll tests597Total599.9%Jo-140.7%PL-720.3%PL-1250.8%SRP-54101.7%Mi-240.7%Ku30.5%PM-Scl 100254.2%Scl-7071.2%Figure 1.

MSAs had an associated CK result in 75% of internal and 12% of GP requests. A cohort of 17 patients had positive MSAs (3 x SRP, 1 x PL-7, 1 x Jo-1, 2 x Mi-2, 1 x Ku, 8 x PM-Scl100 and 1 x Scl-70) with normal CK.

Of the 41 GP requests, MSA had been requested by the lab on the basis of ANA pattern for 33 (80%) of them, 3 of which were positive (2 x Scl-70, 1 x SRP-54).

Conclusion:

Demand for MSA from the Respiratory department (screening for ILD) currently exceeds demand from Neurology and from Rheumatology. In the GP cohort, 33 requests (80% of GPs, 5% of all requests) were generated by the laboratory.

A cohort of patients with normal CK results had a positive MSA, implying CK alone cannot be used to limit test access. Interestingly, 10 positive results had no CK requested implying they were not being investigated for myositis.

Further work is needed to determine the specificity and sensitivity of these antibodies for patients with clinically defined myositis, and the appropriateness of allowing the test to be applied in the absence of any clinical evidence of IIM.

The findings of this audit need to be further extended to look at other myositis including other anti-synthetases, HMGCoAR, MDA5, TIF-1γ, NPX-2.

References:

[1]Dalakas MC, Hohlfeld R (2003) Polymyositis and dermatomyositis. Lancet 362:971–982

Disclosure of Interests:

None declared

AB1131 STATISTICAL PROCESS CONTROL AND PROCESS MAPPING QUANTIFY THE EFFECTS OF HISTORICAL CHANGES TO THE CONNECTIVE TISSUE DISEASE TESTING ALGORITHM AND IDENTIFY AREAS FOR FUTURE IMPROVEMENT IN A LARGE DIAGNOSTIC IMMUNOLOGY SERVICE

Background:

Pathology test turnaround times (TATs) are a limiting factor in patient flow through rheumatology services. Quality improvement (QI) methodologies such as Lean use tools including statistical process control (SPC) and process mapping to study the performance of the whole of a clinical pipeline, expose unnecessary complexity (non-value-adding activity), and streamline processes and staff roles.

Objectives:

Understand effects of changes made to CTD testing algorithm over last 12 years by measuring some of the effects on TATs. Model current processes and suggest changes to workflow to improve TAT.

Methods:

High-level flow diagrams of the current testing algorithm, and low-level process maps of analyser and staff processes were drawn.

Activity and TATs (working days between report and booking date) for ANA, ENA, DNA and CCP tests were plotted as XmR control charts.

Results:

Finding 1: Largest referral laboratory does not currently operate a separate DNA monitoring workstream, resulting in unnecessary ANA and ENA testing (figure 1).

Figure 1.

Current testing strategy (left) and suggested improvement (right)

Finding 2:Samples are handed off between 3 different lab benches, each of which may be staffed by a different staff member on a different day, and results processing involves handoff to a further 2 different staff members.

Finding 3:ANA demand is close to capacity, ENA demand exceeds current capacity (table 1).

Table 1.

Demand for ANA, ENA and DNA tests, compared to capacity

TestMedian Demand(tests/ day)Approx. Capacity(tests/ day)NotesANA74100Close to 80% recommended by the ILGsENA3836*Less capacity than demand!!DNA34100Plenty

Finding 4:Stopping screening DNA requests on ANA result increased the number of DNA tests performed by about 10 samples per day (30%), but decreased turnaround time by a similar proportion (3.3 to 2.3 days, figure 2). It also reduced turnaround times of ANA and ENA tests.

Figure 2.

Control chart of average TAT of dsDNA antibodies by request date

Conclusion:

Typically for a QI project, the initially simple CTD testing pipeline has accumulated many changes made without consideration of whole system performance, and is now a struggle to run.

Improvement ideas to be explored from this work include:

Disclosure of Interests:

None declared

Altered natural killer cell responses linked to allergen sensitization in patients with atopic dermatitis

Atopic dermatitis (AD) is a common chronic inflammatory disease associated with skin barrier dysfunction. AD often precedes the development of atopic co-morbidities, including food allergy, asthma and allergic rhinitis. The contributions of natural killer (NK) cells to pathogenesis of AD and progression to allergic disease are unclear. Peripheral blood mononuclear cells (PBMCs) were isolated from blood samples collected from n=82 children participating in the Mechanisms of Progression of Atopic Dermatitis to Asthma (MPAACH) study, a cohort of toddlers with AD. The children underwent skin prick testing to 11 aeroallergens and 6 foods, and wheezing was defined as one or more episodes of wheezing in the past 12 months. We used flow cytometry to evaluate the phenotype of NK cells in patient PBMC from MPAACH subjects. Our analyses revealed that CD56brightNK cells derived from sensitized children expressed significantly less NKG2D (73.8 ± 3.0 % versus 82.3 ± 2.7 %, respectively, p=0.020) and more TIM-3 (440 ± 462 versus 353 ± 391 median fluorescence intensity, respectively, p=0.085) compared to non-sensitized children. Increased expression of TIM-3 on CD56neg NK cells was also associated with wheezing (47.5 ± 0.51 % versus 19.2 ± 0.40 %, p=0.020). Collectively, these observations suggest that changes within the NK-cell repertoire may promote progressive development of AD and atopic co-morbidities in early life.

The VEGF-A exon 8 splicing-sensitive fluorescent reporter mouse is a novel tool to assess the effects of splicing regulatory compounds in vivo

Vascular endothelial growth factor (VEGF)-A is differentially spliced to give two functionally different isoform families; pro-angiogenic, pro-permeability VEGF-A_xxx and anti-angiogenic, anti-permeability VEGF-A_xxxb. VEGF-A splicing is dysregulated in several pathologies, including cancer, diabetes, and peripheral arterial disease. The bichromatic VEGF-A splicing-sensitive fluorescent reporter harboured in a transgenic mouse is a novel approach to investigate the splicing patterns of VEGF-A in vivo. We generated a transgenic mouse harbouring a splicing-sensitive fluorescent reporter designed to mimic VEGF-A terminal exon splicing (VEGF8ab) by insertion into the ROSA26 genomic locus. dsRED expression denotes proximal splice site selection (VEGF-A_xxx) and eGFP expression denotes distal splice site selection (VEGF-A_xxxb). We investigated the tissue-specific expression patterns in the eye, skeletal muscle, cardiac muscle, kidney, and pancreas, and determined whether the splicing pattern could be manipulated in the same manner as endogenous VEGF-A by treatment with the SRPK1 inhibitor SPHINX 31. We confirmed expression of both dsRED and eGFP in the eye, skeletal muscle, cardiac muscle, kidney, and pancreas, with the highest expression of both fluorescent proteins observed in the exocrine pancreas. The ratio of dsRED and eGFP matched that of endogenous VEGF-A_xxx and VEGF-A_xxxb. Treatment of the VEGF8ab mice with SPHINX 31 increased the mRNA and protein eGFP/dsRED ratio in the exocrine pancreas, mimicking endogenous VEGF-A splicing. The VEGF-A exon 8 splicing-sensitive fluorescent reporter mouse is a novel tool to assess splicing regulation in the individual cell-types and tissues, which provides a useful screening process for potentially therapeutic splicing regulatory compounds in vivo.

Short communication: Mycolicibacterium smegmatis, basonym Mycobacterium smegmatis, causing pyogranulomatous mastitis and its cross-reactivity in bovine (para)tuberculosis testing

Different mycobacterial species are encountered in bovine medicine. The fastidiously growing mycobacteria (Mycobacterium bovis as the cause of bovine tuberculosis, and Mycobacterium avium ssp. paratuberculosis, MAP, as the cause of paratuberculosis) are well known and targeted in eradication/control or monitoring programs in different countries, whereas the rapidly growing species is only rarely identified from bovine disease. The latter have occasionally been reported as the cause of bovine clinical mastitis, but recent reports are scarce. In this study, Mycolicibacterium smegmatis (basonym Mycobacterium smegmatis) was identified as cause of granulomatous, relapsing clinical mastitis in 2 cows from one Belgian dairy herd. Milk, blood, and fecal samples were collected, as well as tissue samples after the cows were culled. Serological analysis conducted on milk and serum samples resulted in positive reactions for MAP, but negative for Mycobacterium bovis. Production of IFN-γ showed sensitization with mycobacteria or similar organisms, other than M. bovis, in one cow. Detection of MAP by bacteriological culture and IS900-based quantitative PCR on milk and feces remained negative. In conclusion, this paper describes M. smegmatis as a cause of bovine clinical mastitis in Belgium and suggests cross-reactivity of the intramammary M. smegmatis infection with routinely used serological tests for MAP.

The rationale of opportunistic bilateral salpingectomies (OBS) during benign gynaecological and obstetric surgery: a consensus text of the Flemish Society of Obstetrics and Gynaecology (VVOG)

Ovarian cancer (OC), is a disease difficult to diagnose in an early stage implicating a poor prognosis. The 5-year overall survival in Belgium has not changed in the last 18 years and remains 44 %. There is no effective screening method (secondary prevention) to detect ovarian cancer at an early stage. Primary prevention of ovarian cancer came in the picture through the paradigm shift that the fallopian tube is often the origin of ovarian cancer and not the ovary itself. Opportunistic bilateral salpingectomy (OBS) during benign gynaecological and obstetric surgery might have the potential to reduce the risk of ovarian cancer by as much as 65 %. Bilateral risk-reducing salpingectomy during a benign procedure is feasible, safe, appears to have no impact on the ovarian function and seems to be cost effective. The key question is whether we should wait for a RCT or implement OBS directly in our daily practice. Guidelines regarding OBS within our societies are therefore urgently needed. Our recommendation is to inform all women without a child wish, undergoing a benign gynaecological or obstetrical surgical procedure about the pro's and the con's of OBS and advise a bilateral salpingectomy. Furthermore, there is an urgent need for a prospective registry of OBS. The present article is the consensus text of the Flemish Society of Obstetrics and Gynaecology (VVOG) regarding OBS.

The effect of mastitis management input and implementation of mastitis management on udder health, milk quality, and antimicrobial consumption in dairy herds

The main objective of this study was to evaluate evolutions in herd-level antimicrobial consumption (AMC) and in udder health and milk quality parameters between herds that received mastitis management input on a regular basis (actively advised by the first author; referred to as intervention herds) and herds that did not (referred to as control herds). Strikingly, herds in the intervention group had a significantly higher prevalence of new intramammary infections compared with those in the control group. No significant differences were observed in the percentage of chronically infected cows, the bulk milk somatic cell count, and the bacterial and coliform count between the intervention and control herds, nor did the herd-level AMC differ between them. Furthermore, the level of mastitis management applied in each herd was assessed and scored [mastitis management score (MMS); higher is better], as was the level of implementation of different recommended mastitis management practices over time, expressed as the mastitis management implementation score (MMIS; higher is better). A large variation was observed in MMS and MMIS in the intervention herds (median = 16 and range = 12 to 22; median = 13 and range = -5 to 31, respectively) and the control herds (median = 16 and range = 9 to 22; median = 9 and range = -13 to 22, respectively). Also, intervention herds in which the herd veterinarian attended each herd visit executed by the first author had a higher MMS and MMIS (median = 20 and 24, respectively) compared with herds in which the veterinarian sometimes (median = 16 and 17, respectively) or never (median = 16.5 and 7.5, respectively) attended the herd visits. Further, the association between MMS or MMIS on one hand and udder health, milk quality, and the herd-level AMC over time on the other was studied using the data of both groups of herds. Better mastitis management was associated with a reduction in the consumption of antimicrobials that are critically important for human health over time and with lower bacterial counts and bulk milk somatic cell count. Better mastitis management can be helpful in obtaining better milk quality and more responsible use of critically important antimicrobials on dairy farms.

Leaders promote attendance in sport and exercise sessions by fostering social identity

Sport and exercise participation exert a positive effect on numerous aspects of individuals' health. Although sport and exercise leaders have generally been observed to play a key role in shaping group members' behavior, our understanding of their impact on group members' attendance in sport and exercise sessions is limited. To address this, and building on promising findings in other domains, we examined the associations between perceptions of sport and exercise leaders' engagement in social identity leadership, group identification, and attendance. A sample of 583 participants from sports teams (n = 307) and exercise groups (n = 276) completed questionnaires measuring identity leadership, group identification, and attendance. Analyses demonstrated that perceptions of leader engagement in social identity leadership were positively associated with members' group identification, and that this in turn was positively associated with their attendance in either a sports group or an exercise group. Moreover, there was a significant indirect effect for perceptions of leader engagement in identity leadership on group members' attendance through their greater identification with these groups. Findings highlight the importance of considering the impact sport and exercise leaders have on group members' attendance and suggest that leaders who represent, advance, create, and embed a shared sense of identity (ie, a shared sense of "us") among attendees can promote participation in sport and exercise.

Computer-assisted surgery compared to fluoroscopy in curettage of atypical cartilaginous tumors / chondrosarcoma grade 1 in the long bones

Introduction

Fluoroscopy is currently the standard imaging modality for curettage of atypical cartilaginous tumors/chondrosarcoma grade 1 (ACT/CS1). Computer-assisted surgery (CAS) is a possible alternative, offering higher resolution imaging and continuous three-dimensional feedback without ionizing radiation use. CAS hypothetically makes curettage more accurate, thereby decreasing residue or recurrence rate. This study aims to compare CAS and fluoroscopy in curettage of ACT/CS1.

Patients and methods

A single center retrospective cohort study was performed. CAS and fluoroscopy were used in parallel. Included were patients who had curettage for ACT/CS1in the long bones, with a minimum follow-up of 24 months. Tumor volume was determined on pre-operative MRI scans. Outcome comprised local recurrence rates, residue rates, complications and procedure time.

Results

Seventy-seven patients were included, 17 in the CAS cohort, 60 in the fluoroscopy cohort. Tumor volume was significantly larger in the CAS cohort (p = 0.04). There were no recurrences in either group. Residual tumor (2/17 vs. 7/60), complications did not differ significantly: fracture rate (3/17 vs. 6/60); nor did surgical time (1.26h vs. 1.34h).

Discussion

CAS curettage showed good oncologic results. Outcome was comparable to fluoroscopy, while not using ionizing radiation. There was no significant difference in surgical time. Residue rates can likely be decreased with specific software functions and surgical tools.

Colour change in a structural ornament is related to individual quality, parasites and mating patterns in the blue tit

Carry-over effects refer to processes that occur in one season and influence fitness in the following. In birds, two costly activities, namely reproduction and moult, are restricted to a small time window, and sometimes overlap. Thus, colour in newly moulted feathers is likely to be affected by the costs of reproduction. Using models of bird vision we investigated male colour change in a free-living population of blue tits (Cyanistes caeruleus) in three sampling occasions: spring 1, winter and spring 2. We related crown, tail, breast and cheek feather colouration after the moult (winter) to the intensity of infections by blood parasites during reproduction (spring 1). In the following spring (spring 2), we explored mating patterns with respect to changes in feather colour (springs 1 vs. 2). Males that were less intensely infected by the malaria parasite Plasmodium while breeding showed purer white cheek feathers in winter, which may indicate higher feather quality. Increased brightness in the white cheek was associated with better body condition during reproduction. In the following season, males with brighter cheeks paired with females that had noticeably brighter cheek patches compared to the male's previous mate. These results suggest that the conditions experienced during reproduction are likely to affect moult and thus feather colouration, at least in the white patch. High quality individuals may allocate resources efficiently during reproduction increasing future reproductive success through variation in mating patterns. Carry-over effects from reproduction might extend not only to the non-breeding phase, but also to the following breeding season.

Isolation of single cells for protein therapeutics using microwell selection and Surface Plasmon Resonance imaging

Here the feasibility is demonstrated that by combining Surface Plasmon Resonance Imaging (SPRi) and self-sorting microwell technology product secretion of individual cells can be monitored. Additionally isolation of the selected cells can be performed by punching the cells from the microwells using coordinates of the positions of microwells obtained with SPRi. Cells of interest can be retrieved sterile from the microwell array for further cultivation.

Diversity in warning coloration is easily recognized by avian predators

Warning coloration is a widespread strategy to alert predators about prey unprofitability. The success of this strategy partly depends on predators being able to learn and recognize certain signals as indicators of toxicity, and theory predicts that this is easier if signals converge on similar colours. However, the diversity in warning signal form is astonishing, contradicting predictions. Here, we quantified ladybird signal diversity with respect to avian vision, measuring how unique and discernible each signal is from one another. In addition, we measured signal conspicuousness against a series of backgrounds, namely an average green, average brown, and where we collected each species, to determine whether signals are more contrasting against the ladybirds' local substrates than compared to average ones. This allowed us to establish whether there are local adaptations in conspicuousness that promote signal diversity. We found that while ladybird signals are unique and recognizable, specialist species are more contrasting against the background they are most commonly found on. However, overall our study suggests that warning signals have evolved to be effective against a wide range of natural backgrounds, partly explaining the success of this strategy in nature.

Evaluation of accuracy and precision of CT-guidance in Radiofrequency Ablation for osteoid osteoma in 86 patients

Background and purpose

Osteoid osteoma is a benign skeletal tumour that accounts for 2–3% of all bone tumours. The male-to-female ratio is around 4:1 and it predominates in children and young adults. The most common symptom is pain, frequently at night-time. Historically the main form of treatment has been surgical excision. With the development of Radiofrequency Ablation (RFA) there is a percutaneus alternative. Success rates of RFA are lower but the main advantage is the minimal invasive character of the therapy and the low complication rate. As a result of the minimal invasiveness the hospitalization- and rehabilitation periods are relatively short. However, in current literature no values for accuracy and precision are known for the CT-guided positioning.

Methods

Accuracy and precision of the needle position are determined for 86 procedures. Furthermore the population is divided into groups based on tumour diameter, location and procedure outcome.

Results

The clinical success rate was 81.4%. In 79% of procedures complete ablation was achieved. Accuracy was 2.84 mm on average, precision was 2.94 mm. Accuracy was significantly lower in more profound lesions. Accuracy in tibia and fibula was significantly higher compared to the femur. No significant difference was found between different tumour diameters.

Interpretation

The accuracy and precision found are considered good. Needle position is of major importance for procedure outcomes. The question however rises how the results of this therapy will turn out in treatment of larger tumours.

Evolving sepsis definitions and their impact on Acute Medical Units

BACKGROUND

There are currently several different definitions for sepsis. This study looked at what proportion of acute medical admissions were identified by the different definitions, what correlation they have, and how many patients would require a review with results in 1 hour.

METHODS

Data on 212 admissions was collected, on time of admission and review, and number of patients with sepsis by each diagnostic criteria calculated.

RESULTS

The NICE criteria identified 69% of admissions as requiring review within one hour, compared to 6% with qSOFA and 18% with previous sepsis definitions. The mean time to review was 1hr 18min, and only 50% of patients meeting the NICE criteria were reviewed within one hour.

CONCLUSIONS

The proposed NICE guidance will be challenging to implement with current resources.

[Clinical pathway evaluation for left colectomy in abdominal surgery]

At the end of 2008, a left colectomy clinical pathway was implemented at Clinique Saint-Joseph (CHC) in Liège (Belgium). A sample of 213 patients with benign or malignant pathology requiring laparoscopic left colon resection was included in this clinical pathway during the years 2009 to 2015. We focused on the compliance with the protocol, on the complication rate and the incidence of re-hospitalization within 30 days after surgery. In comparison with a historical control group, we observed that the compliance was excellent (superior to 80 %) from 2009 to 2015. The re-hospitalization did not differ though the complication rate decreased. Although the hospital stay was not our primary objective, it decreased significantly from 8 to 4 days (average). This analysis leads to the conclusion that the introduction of a clinical pathway, when it is well prepared and brings together all the implicated persons with the same goal, is directly beneficial to the patient and the quality of its management.

Survivors of childhood leukaemia treated with haematopoietic stem cell transplantation and total body irradiation should undergo screening for diabetes by oral glucose tolerance tests

AIMS

Childhood cancer survivors treated with haematopoietic stem cell transplantation (HSCT) and total body irradiation are at an increased risk of developing diabetes early in life due to insulin resistance and β-cell dysfunction, but the optimal screening method is unknown. The National Institute for Health and Care Excellence guidelines for community diabetes screening recommend using fasting glucose ≥ 7 mmol/l and/or HbA1c ≥ 48 mmol/mol (6.5%) for diagnosis and, fasting glucose 5.5-6.9 mmol/l or HbA1c 42-47 mmol/mol (6-6.5%) to indicate high risk. This study aimed to evaluate the sensitivities of fasting glucose and HbA1c in the diagnosis of diabetes and impaired glucose tolerance in childhood HSCT survivors.

METHOD

The patients were 35 (male = 19) HSCT survivors from a single UK centre under follow-up from 2006 to 2013. Patients had a median age (range) of 19.2 (13.1-26.2) years and had been treated for acute lymphoblastic (n = 31) or myeloid (n = 4) leukaemia when aged 7.8 (2.4-16.7) years. The outcome measures were oral glucose tolerance test (OGTT), fasting glucose and HbA1c .

RESULTS

OGTT identified 6 patients with diabetes (120-min glucose ≥ 11.1 mmol/l), 12 with impaired glucose tolerance (120-min glucose 7.8-11.0 mmol/l) and 2 with impaired fasting glucose (≥ 7 mmol/l). Fasting glucose ≥ 7 mmol/l or HbA1c ≥ 48 mmol/mol identified two of the six patients with diabetes diagnosed on OGTT. Fasting glucose ≥ 5.5 mmol/l and HbA1c ≥ 42 mmol/mol identified three and two patients, respectively, with diabetes. Only 1 of 12 patients with impaired glucose tolerance had a fasting glucose ≥ 5.5 mmol/l and none had HbA1c ≥ 42 mmol/mol (≥ 6%).

CONCLUSIONS

The fasting glucose and HbA1c cut-offs used in UK population screening only identified one-third of HSCT survivors with diabetes and do not identify those at risk. Diabetes screening in HSCT survivors requires standard OGTTs.

Duloxetine in OsteoArthritis (DOA) study: study protocol of a pragmatic open-label randomised controlled trial assessing the effect of preoperative pain treatment on postoperative outcome after total hip or knee arthroplasty

INTRODUCTION

Residual pain is a major factor in patient dissatisfaction following total hip arthroplasty or total knee arthroplasty (THA/TKA). The proportion of patients with unfavourable long-term residual pain is high, ranging from 7% to 34%. There are studies indicating that a preoperative degree of central sensitisation (CS) is associated with poorer postoperative outcomes and residual pain. It is thus hypothesised that preoperative treatment of CS could enhance postoperative outcomes. Duloxetine has been shown to be effective for several chronic pain syndromes, including knee osteoarthritis (OA), in which CS is most likely one of the underlying pain mechanisms. This study aims to evaluate the postoperative effects of preoperative screening and targeted duloxetine treatment of CS on residual pain compared with care-as-usual.

METHODS AND ANALYSIS

This multicentre, pragmatic, prospective, open-label, randomised controlled trial includes patients with idiopathic hip/knee OA who are on a waiting list for primary THA/TKA. Patients at risk for CS will be randomly allocated to the preoperative duloxetine treatment programme group or the care-as-usual control group. The primary end point is the degree of postoperative pain 6 months after THA/TKA. Secondary end points at multiple time points up to 12 months postoperatively are: pain, neuropathic pain-like symptoms, (pain) sensitisation, pain catastrophising, joint-associated problems, physical activity, health-related quality of life, depressive and anxiety symptoms, and perceived improvement. Data will be analysed on an intention-to-treat basis.

ETHICS AND DISSEMINATION

The study is approved by the local Medical Ethics Committee (METc 2014/087) and will be conducted according to the principles of the Declaration of Helsinki (64th, 2013) and the Good Clinical Practice standard (GCP), and in compliance with the Medical Research Involving Human Subjects Act (WMO).

TRIAL REGISTRATION NUMBER

2013-004313-41; Pre-results.