Performance evaluation of the LumiraDx quantitative microfluidic point-of-care CRP test

C-reactive protein (CRP) is an established acute-phase marker for infection, inflammation and tissue injury, used to guide clinical decision-making in primary and secondary care. This study compared the analytical performance of the quantitative microfluidic point-of-care LumiraDx CRP Test to a laboratory-based reference method (Siemens RCRP Flex assay on the Dimension® Xpand®) and evaluated equivalence of sample matrices (blood versus plasma) in point-of-care settings using samples from patients presenting with symptoms of infection or inflammation. The LumiraDx CRP Test demonstrated close agreement with the lab reference test (range, 5.1 to 245.2 mg/L, r = 0.992, slope = 0.998, intercept = -0.476; n = 205) and notable agreement between fingerstick and venous blood and plasma (r = 0.974-0.983; n = 44). Paired replicate precision had mean coefficients of variation of 6.4 % (plasma), 6.6 % (capillary direct) and 8.1 % (venous blood); overall error rates were 2.9 %. The quantitative LumiraDx CRP Test showed robust analytical performance across sample matrices and close agreement compared to the laboratory reference method when used at the point of care.

Developing an implementation intervention for managing acute vertigo in the emergency department

BACKGROUND

There are evidence-based bedside tests for diagnosing acute vertigo, but no evidence-based strategies to support clinicians in implementing them. The purpose of this study was to design an implementation strategy for treating acute vertigo by examining current facilitators and barriers to using these tests in the ED using the principles of implementation science.

METHODS

A survey was developed using the Theoretical Domains Framework and Consolidated Framework for Implementation Research to examine barriers and facilitators for using HINTS+ (head impulse, nystagmus, test of skew, plus hearing) and Dix-Hallpike tests. The survey was sent to emergency clinicians (ECs) in a teaching hospital in London, UK, between May and September 2022. Semistructured interviews were conducted simultaneously, and data examined using direct content analysis. Implementation strategies were then selected based on the Expert Recommendations for Implementing Change framework.

RESULTS

Fifty-one ECs responded to the survey and six ECs volunteered for interview. Less than half reported using the bedside tests to make a diagnosis. The most common barriers were beliefs about complexity, a lack of supporting materials, memory, lack of skills and negative experiences. The interview data revealed negative beliefs about the necessity, validity, safety and practicality. There were also barriers in the ED environment (eg, lack of space). There was a strong perception that the current approach to managing acute vertigo needed to change and ECs view this as part of their professional role and responsibility. Based on clinician input, the authors selected strategies to improve diagnostic efforts, which included guidelines for training, developing vertigo champions, protocols, memory aids, audit and feedback.

CONCLUSION

This study found several barriers to managing acute vertigo such as memory constraints, and inadequate supporting materials and training, although a robust desire for change. The implementation strategy's initial phase is described, which must now be tested.

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Configurations and outcomes of acute hospital care for frail and older patients with moderate to major trauma: a systematic review

OBJECTIVE

To systematically review research on acute hospital care for frail or older adults experiencing moderate to major trauma.

SETTING

Electronic databases (Medline, Embase, ASSIA, CINAHL Plus, SCOPUS, PsycINFO, EconLit, The Cochrane Library) were searched using index and key words, and reference lists and related articles hand-searched.

INCLUDED ARTICLES

Peer-reviewed articles of any study design, published in English, 1999-2020 inclusive, referring to models of care for frail and/or older people in the acute hospital phase of care following traumatic injury defined as either moderate or major (mean or median Injury Severity Score ≥9). Excluded articles reported no empirical findings, were abstracts or literature reviews, or referred to frailty screening alone.

METHODS

Screening abstracts and full text, and completing data extractions and quality assessments using QualSyst was a blinded parallel process. A narrative synthesis, grouped by intervention type, was undertaken.

OUTCOME MEASURES

Any outcomes reported for patients, staff or care system.

RESULTS

17 603 references were identified and 518 read in full; 22 were included-frailty and major trauma (n=0), frailty and moderate trauma (n=1), older people and major trauma (n=8), moderate or major trauma (n=7) 0r moderate trauma (n=6) . Studies were observational, heterogeneous in intervention and with variable methodological quality.Specific attention given to the care of older and/or frail people with moderate to major trauma in the North American context resulted in improvements to in-hospital processes and clinical outcomes, but highlights a relative paucity of evidence, particularly in relation to the first 48 hours post-injury.

CONCLUSIONS

This systematic review supports the need for, and further research into an intervention to address the care of frail and/or older patients with major trauma, and for the careful definition of age and frailty in relation to moderate or major trauma. INTERNATIONAL PROSPECTIVE REGISTER OF SYSTEMATIC REVIEWS PROSPERO: CRD42016032895.

1497 Methods to diagnose carbon monoxide exposure: A scoping review

Aims, Objectives and Background

Carbon-monoxide (CO) is a colourless, odourless gas produced from incomplete combustion of carbon-containing fuels. Measurement of CO levels to diagnose exposure is difficult due to its short half-life. The effects of exposure to CO range from mild symptoms, such as headache, to neurotoxicity and death.

In this scoping review we aimed to establish the existing methods used in clinical practice and research to determine CO exposure and map the diagnostic cut-off values used.

Method and design

We undertook a scoping review to establish methods used in clinical practice and research to measure CO exposure and to determine diagnostic thresholds in each. EMBASE, Medline and CINAHL databases were searched for published articles in English from 2002 onwards using keywords ‘carbon monoxide’, ‘poisoning’ and ‘diagnosis’. Two reviewers independently screened published abstracts for inclusion, with a third arbiter where there was lack of agreement between reviewers. Full text papers were then reviewed, and data extracted on methods used to measure CO level, diagnostic cut-off values, and whether CO exposure was from a known or unknown source.

Results and Conclusion

A total of 85 papers were identified meeting the inclusion and exclusion criteria. The most common methods identified for diagnosing CO exposure were measurement of carboxyhaemoglobin (COHb) in whole blood (50.5%) and CO-oximeter spectrophotometrics (20%). Diagnostic values were poorly reported and varied in non-smokers and smokers. Exhaled CO levels using breath analysers (8.2%) and ambient CO measurement (11.7%) were also documented. Diagnostic threshold values varied between 2–5% in non-smokers and 10–15% in smokers. Several methods are used in clinical practice and research to diagnose CO exposure. There is variation in the cut-off values used to make this diagnosis which is challenging for clinicians and makes comparison of research findings difficult.

1397 ’I don’t have time’: strategies for increasing research engagement in emergency department clinicians

Aims, Objectives and Background

Clinicians who engage in generating research knowledge are more likely to implement findings in practice leading to better patient outcomes. Having an emergency department (ED) culture that gives significance to research is an important factor in supporting clinicians to develop the skill and ability to participate and perform research.

In 2018 the ED at St George’s Hospital, London introduced an embedded research group with a dedicated leadership position, bringing together research delivery staff and clinical academics to increase the research culture in the department. This study aimed to investigate the impact of this model on research engagement amongst the ED clinical multi-disciplinary team.

Method and Design

A case study design approach was used involving:

A registry of the research-related initiatives undertaken in the department

Analysing the metrics of engagement in research activities by clinical staff, including number of publications and academic training uptake

Data were collected between April 2018 and March 2022.

Results and Conclusion

Registry data show 41 distinct initiatives established in the time period led or delivered by the research group. These included face-to-face teaching, publication writing support, a research internship program and small grant funding. Research outputs (publications or conference abstracts) showed a 23-fold increase from two in 2018 to 47 in 2021.

The project to develop a research culture in ED has had a positive effect on both type and number of research-related activities across all clinical staff groups. This case study illustrates how research activities delivered close to clinical practice under visible, focused clinical research leadership can increase research engagement. Challenges of a clinically complex context were overcome by embedding a multidisciplinary clinical research unit, linking research delivery with clinical academic development. This model could be replicated in other settings.

Cross-sectional study of carbon monoxide alarm use in patients attending the emergency department: a multicentre survey protocol

INTRODUCTION

The most common place for unintentional, non-fire-related carbon monoxide (CO) exposure to occur is in the home, but this is preventable if CO producing sources are properly maintained and CO alarms/detectors are in use. It is estimated that less than half of all homes have a CO alarm, but there is variation across countries, housing types and different demographic and socioeconomic groups. The purpose of this study is to provide up-to-date data on the use of CO alarms by surveying attendees to emergency departments using an online anonymous questionnaire.

METHODS AND ANALYSIS

A multicentre prospective, cross-sectional survey of 4000 patients or carers in three emergency departments will be used. A questionnaire comprising of a maximum of 14 items will be administered following completion of an informed consent process. Data collected include participant demographics, household information and CO alarm use. Statistical analyses will comprise descriptive techniques to present respondents' use of CO alarms and examine associations between alarm use and participant characteristics. The proportion of homes with CO alarms installed will be calculated for all subjects and for selected subgroups.

ETHICS AND DISSEMINATION

The study obtained ethical approval from the Westminster Research Ethics Committee (REC number 1/PR/1657). Informed consent will be obtained prior to the participant undergoing any activities that are specifically for the purposes of the study. Findings will be published in scientific journals, presented to national and international conferences and disseminated to CO safety groups.

TRIAL REGISTRATION NUMBER

ISRCTN registry 12562718.

Cytomegalovirus infection is a risk factor for venous thromboembolism in ANCA-associated vasculitis

BACKGROUND

Venous thromboembolism (VTE) is a common complication in patients with anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV) and confers significant morbidity and mortality. Both acute and past cytomegalovirus (CMV) infection have been identified as risk factors for VTE in immunocompetent and immunosuppressed individuals. Here, we examine whether past exposure to CMV is a risk factor for VTE amongst patients with AAV.

METHODS

We retrospectively analysed outcomes of patients with a new diagnosis of AAV from a UK cohort. All confirmed cases of VTE where CMV IgG serology was available were recorded. Retrospective collection of the same data for patients at a North American centre was used as a validation cohort.

RESULTS

VTE was common with 12% of patients from the study cohort (total 259 patients) developing an event during the median follow-up period of 8.5 years of which 60% occurred within the first 12 months following diagnosis. Sixteen percent of CMV seropositive patients developed a VTE compared with 5% of patients who were seronegative (p = 0.007) and CMV seropositivity remained an independent predictor of VTE in multivariable analysis (HR 2.96 [1.094-8.011] p = 0.033). CMV seropositivity at diagnosis was confirmed as a significant risk factor for VTE in the American validation cohort (p = 0.032).

CONCLUSIONS

VTE is common in patients with AAV, especially within the first year of diagnosis. Past infection with CMV is an independent risk factor associated with VTE in AAV.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Azithromycin versus standard care in patients with mild-to-moderate COVID-19 (ATOMIC2): an open-label, randomised trial

BACKGROUND

The antibacterial, anti-inflammatory, and antiviral properties of azithromycin suggest therapeutic potential against COVID-19. Randomised data in mild-to-moderate disease are not available. We assessed whether azithromycin is effective in reducing hospital admission in patients with mild-to-moderate COVID-19.

METHODS

This prospective, open-label, randomised superiority trial was done at 19 hospitals in the UK. We enrolled adults aged at least 18 years presenting to hospitals with clinically diagnosed, highly probable or confirmed COVID-19 infection, with fewer than 14 days of symptoms, who were considered suitable for initial ambulatory management. Patients were randomly assigned (1:1) to azithromycin (500 mg once daily orally for 14 days) plus standard care or to standard care alone. The primary outcome was death or hospital admission from any cause over the 28 days from randomisation. The primary and safety outcomes were assessed according to the intention-to-treat principle. This trial is registered at ClinicalTrials.gov (NCT04381962) and recruitment is closed.

FINDINGS

298 participants were enrolled from June 3, 2020, to Jan 29, 2021. Three participants withdrew consent and requested removal of all data, and three further participants withdrew consent after randomisation, thus, the primary outcome was assessed in 292 participants (145 in the azithromycin group and 147 in the standard care group). The mean age of the participants was 45·9 years (SD 14·9). 15 (10%) participants in the azithromycin group and 17 (12%) in the standard care group were admitted to hospital or died during the study (adjusted OR 0·91 [95% CI 0·43-1·92], p=0·80). No serious adverse events were reported.

INTERPRETATION

In patients with mild-to-moderate COVID-19 managed without hospital admission, adding azithromycin to standard care treatment did not reduce the risk of subsequent hospital admission or death. Our findings do not support the use of azithromycin in patients with mild-to-moderate COVID-19.

FUNDING

National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford and Pfizer.

Antibody responses after first and second Covid-19 vaccination in patients with chronic lymphocytic leukaemia

B-cell chronic lymphocytic leukaemia (CLL) is associated with immunosuppression and patients are at increased clinical risk following SARS-CoV-2 infection. Covid-19 vaccines offer the potential for protection against severe infection but relatively little is known regarding the profile of the antibody response following first or second vaccination. We studied spike-specific antibody responses following first and/or second Covid-19 vaccination in 299 patients with CLL compared with healthy donors. 286 patients underwent extended interval (10-12 week) vaccination. 154 patients received the BNT162b2 mRNA vaccine and 145 patients received ChAdOx1. Blood samples were taken either by venepuncture or as dried blood spots on filter paper. Spike-specific antibody responses were detectable in 34% of patients with CLL after one vaccine (n = 267) compared to 94% in healthy donors with antibody titres 104-fold lower in the patient group. Antibody responses increased to 75% after second vaccine (n = 55), compared to 100% in healthy donors, although titres remained lower. Multivariate analysis showed that current treatment with BTK inhibitors or IgA deficiency were independently associated with failure to generate an antibody response after the second vaccine. This work supports the need for optimisation of vaccination strategy in patients with CLL including the potential utility of booster vaccines.

Effect of tranexamic acid on intracranial haemorrhage and infarction in patients with traumatic brain injury: a pre-planned substudy in a sample of CRASH-3 trial patients

BACKGROUND

Early tranexamic acid (TXA) treatment reduces head injury deaths after traumatic brain injury (TBI). We used brain scans that were acquired as part of the routine clinical practice during the CRASH-3 trial (before unblinding) to examine the mechanism of action of TXA in TBI. Specifically, we explored the potential effects of TXA on intracranial haemorrhage and infarction.

METHODS

This is a prospective substudy nested within the CRASH-3 trial, a randomised placebo-controlled trial of TXA (loading dose 1 g over 10 min, then 1 g infusion over 8 hours) in patients with isolated head injury. CRASH-3 trial patients were recruited between July 2012 and January 2019. Participants in the current substudy were a subset of trial patients enrolled at 10 hospitals in the UK and 4 in Malaysia, who had at least one CT head scan performed as part of the routine clinical practice within 28 days of randomisation. The primary outcome was the volume of intraparenchymal haemorrhage (ie, contusion) measured on a CT scan done after randomisation. Secondary outcomes were progressive intracranial haemorrhage (post-randomisation CT shows >25% of volume seen on pre-randomisation CT), new intracranial haemorrhage (any haemorrhage seen on post-randomisation CT but not on pre-randomisation CT), cerebral infarction (any infarction seen on any type of brain scan done post-randomisation, excluding infarction seen pre-randomisation) and intracranial haemorrhage volume (intraparenchymal + intraventricular + subdural + epidural) in those who underwent neurosurgical haemorrhage evacuation. We planned to conduct sensitivity analyses excluding patients who were severely injured at baseline. Dichotomous outcomes were analysed using relative risks (RR) or hazard ratios (HR), and continuous outcomes using a linear mixed model.

RESULTS

1767 patients were included in this substudy. One-third of the patients had a baseline GCS (Glasgow Coma Score) of 3 (n=579) and 24% had unilateral or bilateral unreactive pupils. 46% of patients were scanned pre-randomisation and post-randomisation (n=812/1767), 19% were scanned only pre-randomisation (n=341/1767) and 35% were scanned only post-randomisation (n=614/1767). In all patients, there was no evidence that TXA prevents intraparenchymal haemorrhage expansion (estimate=1.09, 95% CI 0.81 to 1.45) or intracranial haemorrhage expansion in patients who underwent neurosurgical haemorrhage evacuation (n=363) (estimate=0.79, 95% CI 0.57 to 1.11). In patients scanned pre-randomisation and post-randomisation (n=812), there was no evidence that TXA reduces progressive haemorrhage (adjusted RR=0.91, 95% CI 0.74 to 1.13) and new haemorrhage (adjusted RR=0.85, 95% CI 0.72 to 1.01). When patients with unreactive pupils at baseline were excluded, there was evidence that TXA prevents new haemorrhage (adjusted RR=0.80, 95% CI 0.66 to 0.98). In patients scanned post-randomisation (n=1431), there was no evidence of an increase in infarction with TXA (adjusted HR=1.28, 95% CI 0.93 to 1.76). A larger proportion of patients without (vs with) a post-randomisation scan died from head injury (38% vs 19%: RR=1.97, 95% CI 1.66 to 2.34, p<0.0001).

CONCLUSION

TXA may prevent new haemorrhage in patients with reactive pupils at baseline. This is consistent with the results of the CRASH-3 trial which found that TXA reduced head injury death in patients with at least one reactive pupil at baseline. However, the large number of patients without post-randomisation scans and the possibility that the availability of scan data depends on whether a patient received TXA, challenges the validity of inferences made using routinely collected scan data. This study highlights the limitations of using routinely collected scan data to examine the effects of TBI treatments.

TRIAL REGISTRATION NUMBER

ISRCTN15088122.

Pharmacokinetics of intramuscular tranexamic acid in bleeding trauma patients: a clinical trial

BACKGROUND

Intravenous tranexamic acid (TXA) reduces bleeding deaths after injury and childbirth. It is most effective when given early. In many countries, pre-hospital care is provided by people who cannot give i.v. injections. We examined the pharmacokinetics of intramuscular TXA in bleeding trauma patients.

METHODS

We conducted an open-label pharmacokinetic study in two UK hospitals. Thirty bleeding trauma patients received a loading dose of TXA 1 g i.v., as per guidelines. The second TXA dose was given as two 5 ml (0·5 g each) i.m. injections. We collected blood at intervals and monitored injection sites. We measured TXA concentrations using liquid chromatography coupled to mass spectrometry. We assessed the concentration time course using non-linear mixed-effect models with age, sex, ethnicity, body weight, type of injury, signs of shock, and glomerular filtration rate as possible covariates.

RESULTS

Intramuscular TXA was well tolerated with only mild injection site reactions. A two-compartment open model with first-order absorption and elimination best described the data. For a 70-kg patient, aged 44 yr without signs of shock, the population estimates were 1.94 h^-1 for i.m. absorption constant, 0.77 for i.m. bioavailability, 7.1 L h^-1 for elimination clearance, 11.7 L h^-1 for inter-compartmental clearance, 16.1 L volume of central compartment, and 9.4 L volume of the peripheral compartment. The time to reach therapeutic concentrations (5 or 10 mg L^-1) after a single intramuscular TXA 1 g injection are 4 or 11 min, with the time above these concentrations being 10 or 5.6 h, respectively.

CONCLUSIONS

In bleeding trauma patients, intramuscular TXA is well tolerated and rapidly absorbed.

CLINICAL TRIAL REGISTRATION

2019-000898-23 (EudraCT); NCT03875937 (ClinicalTrials.gov).

Cytomegalovirus seropositivity is independently associated with cardiovascular disease in non-dialysis dependent chronic kidney disease

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of early death in patients with chronic kidney disease (CKD). Previous work has described an association between Cytomegalovirus (CMV) seropositivity and CVD amongst patients with dialysis dependent end stage renal disease. Whether CMV seropositivity is associated with CVD in non-dialysis dependent CKD has not been established.

AIM

Investigate whether past CMV infection is associated with prevalent CVD in patients with non-dialysis dependent CKD.

DESIGN

A retrospective observational study using the Renal Impairment in Secondary Care cohort, a study evaluating bio-clinical determinants of outcomes in patients with progressive CKD.

METHODS

We assayed cryopreserved serum samples collected at inception for anti-CMV IgG antibodies from 764 patients with stages 2 to 5 CKD (pre-dialysis) and investigated its relationship with prevalent CVD.

RESULTS

Median estimated glomerular filtration was 24 ml/min/1.73 m2 (IQR 19-32). Sixty-eight percent of patients were CMV seropositive. CMV seropositivity was associated with older age, non-Caucasian ethnicity, diabetes and higher social deprivation index score. On univariable analysis, CMV seropositivity correlated with higher systolic blood pressure (P = 0.044), prevalent CVD (P < 0.001), ischaemic heart disease (P < 0.001) and cerebrovascular disease (P = 0.022). On multivariable analysis, CMV seropositive patients nearly twice as likely to have CVD compared to seronegative patients [Odds Ratio (OR) = 1.998, CI 1.231-3.242, P = 0.005].

CONCLUSIONS

In patients with non-dialysis CKD, CMV seropositivity is independently associated with a higher prevalence of CVD.

Diagnostic accuracy of the Troponin-only Manchester Acute Coronary Syndromes (T-MACS) decision aid with a point-of-care cardiac troponin assay

OBJECTIVE

Point-of-care (POC) cardiac troponin (cTn) assays have a rapid turnaround time but are generally less sensitive than laboratory-based assays. Previous research found that the Abbott i-Stat cardiac troponin I (cTnI) assay has good diagnostic accuracy when used with the Troponin-only Manchester Acute Coronary Syndromes (T-MACS) decision aid and serial sampling over 3 hours. Accuracy of other assays may differ. We therefore evaluated the diagnostic accuracy of a different POC cTnI assay with serial sampling over 3 hours, both with T-MACS and when used alone.

METHODS

In a prospective diagnostic accuracy study at eight EDs in England (July 2015-October 2017), we collected clinical data from consenting adults with suspected ACS at the time of assessment in the ED. Blood samples were drawn on arrival and 3 hours later for POC cTnI (Cardio 3 Triage, Alere). The target condition was an adjudicated diagnosis of acute myocardial infarction (AMI), based on reference standard serial laboratory-based cTn testing. We calculated test characteristics for POC cTnI using the limit of detection (LoD, 0.01 µg/L) and the T-MACS decision aid.

RESULTS

Of 347 participants, 59 (14.9%) had AMI. With serial POC cTnI testing over 3 hours, POC cTnI at the LoD cut-off ruled out AMI in 193 (55.6%) patients with 98.1% sensitivity (95% CI 89.9% to 100.0%) and 99.5% negative predictive value (NPV, 95% CI 96.5% to 99.9%). T-MACS ruled out AMI in 117 (33.7%) patients with 98.1% sensitivity (95% CI 89.9% to 100%) and 99.2% NPV (95% CI 94.3% to 99.9%). T-MACS ruled in AMI with 97.9% specificity (95% CI 95.8% to 99.5%) and 83.7% positive predictive value (95% CI 70.6% to 91.7%).

CONCLUSIONS

With serial sampling over 3 hours, the Alere Cardio 3 Triage cTnI assay has relatively high NPV for AMI using either the LoD cut-off alone or the T-MACS decision aid. However, wide CIs around the measures of diagnostic accuracy mean that further prospective testing of this strategy is required before clinical implementation.

TRIAL REGISTRATION NUMBER

UKCRN 18000.

The application of a haemorrhage assessment tool in evaluating control of bleeding in a pilot trauma haemorrhage trial

OBJECTIVES

To determine whether it was feasible to use a haemorrhage assessment tool (HAT) within a trauma trial and whether the data obtained could differentiate patients who had achieved haemostasis.

BACKGROUND

Major haemorrhage is one of the leading causes of death worldwide, affecting 40% of trauma patients. Clinical trials evaluating haemostatic interventions often use transfusion outcomes as a primary endpoint. Transfusion is highly dependent on local practice, limiting its reliability as a robust, transferable endpoint.

METHODS

A five-point HAT questionnaire was applied to participants enrolled into the EFIT-1 trial. This RCT evaluated the feasibility of administering a 6 g fibrinogen concentrate to patients with severe trauma haemorrhage.

RESULTS

Of participants, 98% completed a HAT; 75% participants had 'achieved haemostasis' at the time of tool completion, as determined by clinical acumen alone. HAT scores were able to differentiate which participants required transfusion after 3 h. Of participants, 56% were transfused red blood cells when they scored 0-2, compared to 17% with HAT scores between 3 and 5.

CONCLUSION

This study has confirmed the feasibility of using a HAT during the emergency care of patients suffering trauma haemorrhage, and future studies should be conducted to determine its value as an endpoint in haemostasis studies.

Diagnostic Accuracy of a High-Sensitivity Cardiac Troponin Assay with a Single Serum Test in the Emergency Department

OBJECTIVES

We sought to evaluate diagnostic accuracy of a high-sensitivity cardiac troponin I (hs-cTnI) assay for acute coronary syndromes (ACS) in the emergency department (ED). The assay has high precision at low concentrations and can detect cTnI in 96.8% of healthy individuals.

METHODS

In successive prospective multicenter studies (“testing” and “validation”), we included ED patients with suspected ACS. We drew blood for hs-cTnI [Singulex Clarity® cTnI; 99th percentile, 8.67 ng/L; limit of detection (LoD), 0.08 ng/L] on arrival. Patients also underwent hs-cTnT (Roche Elecsys) testing over ≥3 h. The primary outcome was an adjudicated diagnosis of ACS, defined as acute myocardial infarction (AMI; prevalent or incident), death, or revascularization within 30 days.

RESULTS

The testing and validation studies included 665 and 2470 patients, respectively, of which 94 (14.1%) and 565 (22.9%) had ACS. At a 1.5-ng/L cutoff, hs-cTnI had good sensitivity for AMI in both studies (98.7% and 98.1%, respectively) and would have “ruled out” 40.1% and 48.9% patients. However, sensitivity was lower for ACS (95.7% and 90.6%, respectively). At a 0.8-ng/L cutoff, sensitivity for ACS was higher (97.5% and 97.9%, ruling out 28.6% patients in each cohort). The hs-cTnT assay had similar performance at the LoD (24.6% ruled out; 97.2% sensitivity for ACS).

CONCLUSIONS

The hs-cTnI assay could immediately rule out AMI in 40% of patients and ACS in &gt;25%, with similar accuracy to hs-cTnT at the LoD. Because of its high precision at low concentrations, this hs-cTnI assay has favorable characteristics for this clinical application.

Diagnostic accuracy of the T-MACS decision aid with a contemporary point-of-care troponin assay

Objectives

The rapid turnaround time of point-of-care (POC) cardiac troponin (cTn) assays is highly attractive for crowded emergency departments (EDs). We evaluated the diagnostic accuracy of the Troponin-only Manchester Acute Coronary Syndromes (T-MACS) decision aid with a POC cTn assay.

Methods

In a prospective diagnostic accuracy study at eight EDs, we included patients with suspected acute coronary syndromes (ACS). Blood drawn on arrival and 3 hours later was analysed for POC cTnI (i-Stat, Abbott Point of Care). The primary outcome was a diagnosis of ACS, which included both an adjudicated diagnosis of acute myocardial infarction (AMI) based on serial laboratory cTn testing and major adverse cardiac events (death, AMI or coronary revascularisation) within 30 days.

Results

Of 716 patients included, 105 (14.7%) had ACS. Using serial POC cTnI concentrations over 3 hours could have ‘ruled out’ ACS in 198 (31.2%) patients with a sensitivity of 99.0% (95% CI 94.4% to 100.0%) and negative predictive value 99.5% (95% CI 96.5% to 99.9%). No AMIs were missed. T-MACS ‘ruled in’ ACS for 65 (10.4%) patients with a positive predictive value of 91.2% (95% CI 82.1% to 95.9%) and specificity 98.9% (97.6% to 99.6%).

Conclusion

With a POC cTnI assay, T-MACS could ‘rule out’ ACS for approximately one-third of patients within 3 hours while ‘ruling in’ ACS for another 10%. The rapid turnaround time and portability of the POC assay make this an attractive pathway for use in crowded EDs or urgent care centres. Future work should also evaluate use in the prehospital environment.

Optimising antiplatelet utilisation in the acute care setting: a novel threshold for medical intervention in suspected acute coronary syndromes

OBJECTIVES

To construct a model to optimise and personalise recommendations for antiplatelet prescription for patients with suspected acute coronary syndrome (ACS). Acknowledging that emergency physicians work with diagnostic uncertainty, we sought to identify the point at which the probability of ACS is sufficiently high that the benefits of antiplatelet treatment outweigh the risks. Second, we evaluated the projected clinical impact of this approach by using a clinical prediction model (Troponin-only Manchester Acute Coronary Syndromes (T-MACS)) to calculate the probability of ACS.

METHODS

We conducted three systematic reviews, quantifying the effects of ticagrelor, clopidogrel or aspirin-alone treatment strategies for ACS (November 2017). We extracted data for (a) clinical outcomes and (b) weighted patient preferences (utilities) for each outcome. We then constructed utilitarian models, simulating the probability of clinical outcomes with different treatment strategies. This identified the threshold probability of ACS at which each treatment strategy became superior.We validated this approach in a prospective diagnostic study including patients with suspected ACS that was conducted at two large UK teaching hospitals (St George's Hospital London recruited October 2015 to June 2017 and Manchester Royal Infirmary: February 2015 to August 2017). We calculated the probability of ACS using T-MACS. The diagnosis of ACS was adjudicated based on serial high-sensitivity troponin testing and 30-day follow-up.

RESULTS

We constructed three models using data from six studies. Prescribing ticagrelor had greatest overall benefit when the probability of ACS exceeded 8.0%. Below that threshold, aspirin alone yielded greater benefit. The validation study included 660 patients, of which 87 (13.2%) had ACS. Prescription of combined antiplatelet strategy to patients with >8% probability of ACS had greater utility than aspirin alone.

CONCLUSION

Treatment with ticagrelor appears to yield greater net benefit for patients when the probability of ACS >8%. The clinical and cost-effectiveness of this 'precision medicine' approach warrants further study.

Early fibrinogen concentrate therapy for major haemorrhage in trauma (E-FIT 1): results from a UK multi-centre, randomised, double blind, placebo-controlled pilot trial

Background

There is increasing interest in the timely administration of concentrated sources of fibrinogen to patients with major traumatic bleeding. Following evaluation of early cryoprecipitate in the CRYOSTAT 1 trial, we explored the use of fibrinogen concentrate, which may have advantages of more rapid administration in acute haemorrhage. The aims of this pragmatic study were to assess the feasibility of fibrinogen concentrate administration within 45 minutes of hospital admission and to quantify efficacy in maintaining fibrinogen levels ≥ 2 g/L during active haemorrhage.

Methods

We conducted a blinded, randomised, placebo-controlled trial at five UK major trauma centres with adult trauma patients with active bleeding who required activation of the major haemorrhage protocol. Participants were randomised to standard major haemorrhage therapy plus 6 g of fibrinogen concentrate or placebo.

Results

Twenty-seven of 39 participants (69%; 95% CI, 52–83%) across both arms received the study intervention within 45 minutes of admission. There was some evidence of a difference in the proportion of participants with fibrinogen levels ≥ 2 g/L between arms (p = 0.10). Fibrinogen levels in the fibrinogen concentrate (FgC) arm rose by a mean of 0.9 g/L (SD, 0.5) compared with a reduction of 0.2 g/L (SD, 0.5) in the placebo arm and were significantly higher in the FgC arm (p < 0.0001) at 2 hours. Fibrinogen levels were not different at day 7. Transfusion use and thromboembolic events were similar between arms. All-cause mortality at 28 days was 35.5% (95% CI, 23.8–50.8%) overall, with no difference between arms.

Conclusions

In this trial, early delivery of fibrinogen concentrate within 45 minutes of admission was not feasible. Although evidence points to a key role for fibrinogen in the treatment of major bleeding, researchers need to recognise the challenges of timely delivery in the emergency setting. Future studies must explore barriers to rapid fibrinogen therapy, focusing on methods to reduce time to randomisation, using ‘off-the-shelf’ fibrinogen therapies (such as extended shelf-life cryoprecipitate held in the emergency department or fibrinogen concentrates with very rapid reconstitution times) and limiting the need for coagulation test-based transfusion triggers.

Trial registration

ISRCTN67540073. Registered on 5 August 2015.

Alloreactive T cells develop in the very early period following human stem cell transplantation and are characterised by a range of novel features

Allogeneic stem cell transplantation can cure some patients with hematopoietic malignancy but relies on development of a donor T cell alloreactive immune response which develops very early but is difficult to study due to intense lymphopenia. We characterised the phenotype and functional profile of T cells at day 14 in patients undergoing transplantation. T cells were present at very low number but displayed intense proliferation with strong cytokine production. Oligoclonal expansions at day 14 came to represent a substantial fraction of the established T cell pool and were recruited into tissues affected by graft-versus-host disease. Transcriptional analysis uncovered a range of potential targets for immune manipulation including OX40L, TWEAK and CD70. These findings reveal that recognition of alloantigen rapidly drives naïve T cells towards a unique phenotype characterised by intense functional activation. Moreover they demonstrate that early clonal T cell responses are recruited to sites of subsequent tissue damage and provide a range of novel targets for potential therapeutic immunomodulation.

Fourteen days of etoricoxib 60 mg improves pain, hyperalgesia and physical function in individuals with knee osteoarthritis: a randomized controlled trial

OBJECTIVE

Mounting evidence points to the heterogeneity of osteoarthritis (OA) pain, increasing the need for more comprehensive assessment of the efficacy of standard interventions. This study investigated whether 14 days of the selective Cox-2 inhibitor etoricoxib (60 mg/day) would modify self-report of pain intensity and quality, and physical measures of hyperalgesia and function in individuals with knee OA.

DESIGN

This double-blind placebo-controlled trial included 80 community-recruited volunteers with painful knee OA (≥3/10 VAS), randomly allocated to Active or Placebo groups. Self-report measures of pain, stiffness, function Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and pain quality (PainDETECT, Pain Quality Assessment Scale [PQAS]) and physical measures of locomotion and local (knee) and widespread (elbow) hyperalgesia were assessed at Days 0, 4 and 14. Repeated Measures ANOVA analysed group differences.

RESULTS

Significant group × time interaction effects were found for all measures of pain (all p < 0.001), with WOMAC pain sub-score improving by 30.7% by Day 14 and index knee mechanical hyperalgesia improving by 32.6%, whilst Placebo group values worsened. Both self-report and physical tests of function improved (p < 0.001-p = 0.006): WOMAC-function by 28.4%, sit-to-stand and walk time by 13%, pain during locomotion tasks by 12.4-32.6%. Pain quality also significantly improved for the Active and declined for the Placebo group (p < 0.001): PainDETECT score reduced by 23.6% and PQAS paroxsysmal and surface sub-scores by 36.9% and 29.4%. There were also significant improvements in local cold hyperalgesia and widespread mechanical hyperalgesia (10-13.8%).

CONCLUSION

Just 14 days of etoricoxib significantly improves pain intensity and quality, function and local and widespread hyperalgesia, measured by both self-report and physical tests.

Cytomegalovirus infection is associated with an increase in systolic blood pressure in older individuals

BACKGROUND

Cytomegalovirus (CMV) is a chronic infection that is widely distributed in the population. CMV infects a range of tissues, including endothelium, and viral replication is suppressed by the host immune system. Infection is associated with increased risk of mortality from vascular disease in older people, but the mechanisms behind this have not been determined.

AIM

We investigated the association between CMV infection and cardiovascular phenotype in a cohort of healthy elderly donors.

DESIGN

CMV serostatus and cardiovascular parameters were determined in the Lothian Birth cohort, which comprises 1091 individuals aged 70 years in whom many environmental, biochemical and radiological correlates of vascular function have been determined.

METHODS

CMV serostatus was determined by enzyme-linked immunosorbant assay and correlated with a range of biochemical and phenotypic measures.

RESULTS

Sixty-five percent of participants were CMV seropositive, which indicates chronic infection. The mean sitting systolic blood pressure (SBP) was 149.2 mmHg in CMV seropositive individuals compared with 146.2 mmHg in CMV seronegative subjects (SD 18.7 vs. 19.7; P < 0.017). This association between CMV infection and SBP was not attenuated after adjustment for a wide range of biological and socio-economic factors.

CONCLUSIONS

These data show that CMV infection is associated with an increase in SBP in individuals at age 70 years. The magnitude is comparable to environmental variables such as obesity, diabetes or high salt intake. This is the first evidence to show that a chronic infection may be an important determinant of blood pressure and could have significant implications for the future management of hypertension.

Greatly reduced risk of EBV reactivation in rituximab-experienced recipients of alemtuzumab-conditioned allogeneic HSCT

EBV-associated post-transplant lymphoproliferative disease (PTLD) remains an important complication of allogeneic haematopoietic stem cell transplantation (allo-HSCT). We retrospectively analysed the incidence and risk factors for EBV reactivation in 186 adult patients undergoing consecutive allo-HSCT with alemtuzumab T-cell depletion at a single centre. The cumulative incidence of EBV reactivation was 48% (confidence interval (CI) 41-55%) by 1 year, with an incidence of high-level EBV reactivation of 18% (CI 13-24%); 8 patients were concurrently diagnosed with PTLD. Amongst patients with high-level reactivation 31/38 (82%) developed this within only 2 weeks of first EBV qPCR positivity. In univariate analysis age⩾50 years was associated with significantly increased risk of EBV reactivation (hazard ratio (HR) 1.54, CI 1.02-2.31; P=0.039). Furthermore, a diagnosis of non-Hodgkin lymphoma (NHL) was associated with greatly reduced risk of reactivation (HR 0.10, CI 0.03-0.33; P=0.0001) and this was confirmed in multivariate testing. Importantly, rituximab therapy within 6 months prior to allo-HSCT was also highly predictive for lack of EBV reactivation (HR 0.18, CI 0.07-0.48; P=0.001) although confounding with NHL was apparent. Our data emphasise the risk of PTLD associated with alemtuzumab. Furthermore, we report the clinically important observation that rituximab, administered in the peri-transplant period, may provide effective prophylaxis for PTLD.

Cytomegalovirus-Associated CD4(+) CD28(null) Cells in NKG2D-Dependent Glomerular Endothelial Injury and Kidney Allograft Dysfunction

Emerging data suggest that expansion of a circulating population of atypical, cytotoxic CD4(+) T cells lacking costimulatory CD28 (CD4(+) CD28(null) cells) is associated with latent cytomegalovirus (CMV) infection. The purpose of the current study was to increase the understanding of the relevance of these cells in 100 unselected kidney transplant recipients followed prospectively for a median of 54 months. Multicolor flow cytometry of peripheral blood mononuclear cells before transplantation and serially posttransplantation was undertaken. CD4(+) CD28(null) cells were found predominantly in CMV-seropositive patients and expanded in the posttransplantation period. These cells were predominantly effector-memory phenotype and expressed markers of endothelial homing (CX3CR1) and cytotoxicity (NKG2D and perforin). Isolated CD4(+) CD27(-) CD28(null) cells proliferated in response to peripheral blood mononuclear cells previously exposed to CMV-derived (but not HLA-derived) antigens and following such priming incubation with glomerular endothelium resulted in signs of endothelial damage and apoptosis (release of fractalkine and von Willebrand factor; increased caspase 3 expression). This effect was mitigated by NKG2D-blocking antibody. Increased CD4(+) CD28(null) cell frequencies were associated with delayed graft function and lower estimated glomerular filtration rate at end follow-up. This study suggests an important role for this atypical cytotoxic CD4(+) CD28(null) cell subset in kidney transplantation and points to strategies that may minimize the impact on clinical outcomes.

Primary care management of early stage chronic lymphocytic leukaemia is safe and effective

BACKGROUND

Chronic lymphocytic leukaemia (CLL) is the commonest leukaemia in western society. Most patients are detected incidentally at an early stage and require 'watch and wait' follow-up. In the UK, management of Stage A0 CLL varies with some centres advising regular outpatient haematology follow-up, whereas others recommend management within primary care. The safety and effectiveness of these two management options are currently unknown.

METHODS

An observational retrospective cohort study in outpatient Haematology clinics at Queen Elizabeth Hospital Birmingham (QEH) and Birmingham Heartlands Hospital (BHH) and primary care practices in West Midlands, UK. All patients diagnosed with stable stage A0 CLL since 2002 at BHH or QEH were identified. At BHH, patients were discharged to primary care follow-up, whilst QEH patients remained under haematology for follow-up. Evidence of disease progression, need for treatment and overall mortality was documented.

RESULTS

Two hundred and forty-six Stage A0 CLL patients were identified. One hundred and five (43%) patients were discharged to primary care, whilst 141 (57%) patients were followed up in haematology outpatient clinics. No difference in mortality or need for treatment was found between the two groups. Of those discharged, 93 (66%) remained in primary care.

CONCLUSION

The management of stable-stage A0 CLL within primary or secondary care leads to equivalent clinical outcomes. The prevalence of early-stage CLL is expected to increase with the ageing population and management within primary care should be considered as a potentially effective approach.

Contracting with General Dental Services: a mixed-methods study on factors influencing responses to contracts in English general dental practice

Background

Independent contractor status of NHS general dental practitioners (GDPs) and general medical practitioners (GMPs) has meant that both groups have commercial as well as professional identities. Their relationship with the state is governed by a NHS contract, the terms of which have been the focus of much negotiation and struggle in recent years. Previous study of dental contracting has taken a classical economics perspective, viewing practitioners’ behaviour as a fully rational search for contract loopholes. We apply institutional theory to this context for the first time, where individuals’ behaviour is understood as being influenced by wider institutional forces such as growing consumer demands, commercial pressures and challenges to medical professionalism. Practitioners hold values and beliefs, and carry out routines and practices which are consistent with the field’s institutional logics. By identifying institutional logics in the dental practice organisational field, we expose where tensions exist, helping to explain why contracting appears as a continual cycle of reform and resistance.

Aims

To identify the factors which facilitate and hinder the use of contractual processes to manage and strategically develop General Dental Services, using a comparison with medical practice to highlight factors which are particular to NHS dental practice.

Methods

Following a systematic review of health-care contracting theory and interviews with stakeholders, we undertook case studies of 16 dental and six medical practices. Case study data collection involved interviews, observation and documentary evidence; 120 interviews were undertaken in all. We tested and refined our findings using a questionnaire to GDPs and further interviews with commissioners.

Results

We found that, for all three sets of actors (GDPs, GMPs, commissioners), multiple logics exist. These were interacting and sometimes in competition. We found an emergent logic of population health managerialism in dental practice, which is less compatible than the other dental practice logics of ownership responsibility, professional clinical values and entrepreneurialism. This was in contrast to medical practice, where we found a more ready acceptance of external accountability and notions of the delivery of ‘cost-effective’ care. Our quantitative work enabled us to refine and test our conceptualisations of dental practice logics. We identified that population health managerialism comprised both a logic of managerialism and a public goods logic, and that practitioners might be resistant to one and not the other. We also linked individual practitioners’ behaviour to wider institutional forces by showing that logics were predictive of responses to NHS dental contracts at the dental chair-side (the micro level), as well as predictive of approaches to wider contractual relationships with commissioners (the macro level).

Conclusions

Responses to contracts can be shaped by environmental forces and not just determined at the level of the individual. In NHS medical practice, goals are more closely aligned with commissioning goals than in general dental practice. The optimal contractual agreement between GDPs and commissioners, therefore, will be one which aims at the ‘satisfactory’ rather than the ‘ideal’; and a ‘successful’ NHS dental contract is likely to be one where neither party promotes its self-interest above the other. Future work on opportunism in health care should widen its focus beyond the self-interest of providers and look at the contribution of contextual factors such as the relationship between the government and professional bodies, the role of the media, and providers’ social and professional networks.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Targeting ß2 adrenergic receptors regulate human T cell function directly and indirectly

It is well-established that central nervous system activation affects peripheral blood mononuclear cell (PBMCs) function through the release of the catecholamines (Epi) and norepinephrine (NE), which act on ß2-adrenergic receptors (ß2AR). However, most studies have used non-specific stimulation of cells rather than antigen-specific responses. Likewise, few studies have parsed out the direct effects of ß2AR stimulation on T cells versus indirect effects via adrenergic stimulation of antigen presenting cells (APC). Here we report the effect of salmeterol (Sal), a selective ß2AR agonist, on IFN-γ(+) CD4 and IFN-γ(+) CD8 T cells following stimulation with Cytomegalovirus lysate (CMVL-strain AD169) or individual peptides spanning the entire region of the HCMV pp65 protein (pp65). Cells were also stimulated with Staphylococcal enterotoxin B. Additionally, we investigated the effect of Epi and Sal on cytotoxic cell killing of transfected target cells at the single cell level using the CD107a assay. The results show that Sal reduced the percentage of IFN-γ(+) CD4 and IFN-γ(+) CD8 T cells both when applied directly to isolated T cells, and indirectly via treatment of APC. These inhibitory effects were mediated via a ß2 adrenergic-dependent pathway and were stronger for CD8 as compared to CD4 T cells. Similarly, the results show that Sal suppressed cytotoxicity of both CD8 T and NK cells in vitro following stimulation with Chinese hamster ovary cell line transfected with MICA(*009) (T-CHO) and the human erythromyeloblastoid leukemic (K562) cell line. The inhibitory effect on cytotoxicity following stimulation with T-CHO was stronger in NK cells compared with CD8 T cells. Thus, targeting the ß2AR on lymphocytes and on APC leads to inhibition of inflammatory cytokine production and target cell killing. Moreover, there is a hierarchy of responses, with CD8 T cells and NK cells inhibited more effectively than CD4 T cells.

Post-transplant T cell chimerism predicts graft versus host disease but not disease relapse in patients undergoing an alemtuzumab based reduced intensity conditioned allogeneic transplant

In this multicentre retrospective study we have studied the impact of T cell chimerism on the outcome of 133 patients undergoing an alemtuzumab based reduced intensity conditioning allograft (RIC). The median age of the patients was 50 years (range 42-55 years). 77 patients were transplanted using an HLA identical sibling donor while 56 patients received a fully matched volunteer unrelated donor graft. 64 patients had a lymphoid malignancy and 69 were transplanted for a myeloid malignancy. 38 patients (29%) relapsed with no significant difference in risk of relapse between patients developing full donor and mixed donor chimerism in the T-cell compartment on D+90 and D+180 post transplant. Day 90 full donor T cell chimerism correlated with an increased incidence of acute GVHD according to NIH criteria (p=0.0004) and the subsequent development of chronic GVHD. Consistent with previous observations, our results confirmed a correlation between the establishment of T cell full donor chimerism and acute GVHD in T deplete RIC allografts. However our study failed to identify any correlation between T cell chimerism and relapse risk and challenge the use of pre-emptive donor lymphocyte infusions (DLI) in patients with mixed T cell chimerism transplanted using an alemtuzumab based RIC regimen.

Cord blood T cells retain early differentiation phenotype suitable for immunotherapy after TCR gene transfer to confer EBV specificity

Adoptive T cell therapy can be effective for Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disease and melanoma. Transducing high-affinity TCR genes into T lymphocytes is an emerging method to improve potency and specificity of tumor-specific T cells. However, both methods necessitate in vitro lymphocyte proliferation, generating highly differentiated effector cells that display reduced survival and antitumor efficacy postinfusion. TCR-transduction of naive lymphocytes isolated from peripheral blood is reported to provide superior in vivo survival and function. We utilized cord blood (CB) lymphocytes, which comprise mainly naive cells, for transducing EBV-specific TCR. Comparable TCR expression was achieved in adult and CB cells, but the latter expressed an earlier differentiation profile. Further antigen-driven stimulation skewed adult lymphocytes to a late differentiation phenotype associated with immune exhaustion. In contrast, CB T cells retained a less differentiated phenotype after antigen stimulation, remaining CD57-negative but were still capable of antigen-specific polyfunctional cytokine expression and cytotoxicity in response to EBV antigen. CB T cells also retained longer telomeres and in general possessed higher telomerase activity indicative of greater proliferative potential. CB lymphocytes therefore have qualities indicating prolonged survival and effector function favorable to immunotherapy, especially in settings where donor lymphocytes are unavailable such as in solid organ and CB transplantation.

Cytomegalovirus-seropositivity has a profound influence on the magnitude of major lymphoid subsets within healthy individuals

Cytomegalovirus (CMV) infects most individuals and elicits a strong CMV-specific immune response. We have studied the influence of CMV-seropositivity on the size of lymphoid subsets in healthy donors and demonstrate that the virus substantially modulates the peripheral lymphoid pool. CD8(+) T cell numbers are increased in all CMV-seropositive individuals because of a striking 60% increment in the CD8(+) T cell memory pool. The CD45RA(+) resting memory pool is doubled after CMV infection and increases further with age. The magnitude of the naïve CD8(+) T cell pool is dramatically reduced in CMV-seropositive individuals at all ages, and this accelerates the physiological decline by approximately 40 years. The number of CD4(+) effector memory T cells is increased in CMV-seropositive individuals and is differentially accommodated by a reduction in the number of naïve and central memory CD4(+) T cells in young and elderly donors respectively. CMV-seropositivity also increases the total number of B cells in older donors and suppresses the number of CD5(+) B cells. These data reveal that CMV has a profound influence on the immune system of all healthy individuals and add to growing concern regarding the clinical and immunomodulatory significance of CMV infection in healthy donors.

Ethnic variability in human leukocyte antigen-E haplotypes

Human leukocyte antigen-E (HLA-E) is an important nonclassical major histocompatibility complex (MHC) class I (Ib) molecule that acts as the ligand for NKG2A/B/C receptors expressed on natural killer (NK) cells and T cells. Unlike the classical class I molecules, HLA-E is highly conserved in evolution and the biological significance of polymorphism is therefore unclear. Our aim was to investigate the polymorphism in HLA-E gene in three ethnic groups in the UK and to obtain population data relating to any variations observed at this locus. We developed a polymerase chain reaction-sequence-specific primer (PCR-SSP) method for identifying HLA-E single nucleotide polymorphisms (SNPs) in genomic DNA. This was used to investigate the genotype distribution and allele frequency of nine published SNPs in the coding region of HLA-E in 223 Euro-Caucasoid, 60 Afro-Caribbean and 52 Asian healthy individuals. Genotype frequencies were in Hardy-Weinberg equilibrium. No polymorphism was observed for seven previously reported SNPs and these should not be considered polymorphic. However, positions 1114 and 1446 were confirmed as polymorphic and different genotype frequencies were identified at nucleotide position 1114 between the three studied ethnic groups. We present these data together with the intragene haplotype frequencies in these populations. To our knowledge, this is the first description of population frequencies of nine different SNPs in HLA-E in three main large ethnic groups. The data generated from this study will be of importance in the context of describing the effect of HLA-E polymorphism in clinical settings such as transplantation and autoimmune diseases.

Development, impact and outcomes of the Hull Bacteraemia Service

BACKGROUND

Bacteraemia is a significant cause of mortality and healthcare expenditure. Evidence suggests that consultation by an infection specialist may improve outcomes.

AIM

To review the characteristics and outcomes of patients seen by a newly implemented bacteraemia service.

METHODS

Retrospective review of data collected at time of consultation. Economic analyses and benchmarking of outcomes were also performed.

RESULTS

One hundred and fifty-one patients were seen by the service over an 18-month period. Staphylococcus aureus was the most common isolate and central venous lines the most common source. Antibiotics were changed and additional investigations suggested in 62% and 61% of patients, respectively. The 30-day mortality was 19%. Implementation and delivery of the service over the 18-month study period cost pound 22,663 (pound 15,109 per year). The cost per change in antibiotic prescription was pound 244. The cost per 'near-miss' detected was pound 1193. Overall mortality was no higher and possibly lower than in published studies.

CONCLUSION

We believe that this model of care may be suitable for the management of patients with bacteraemia. A study assessing the cost-effectiveness of this approach is required.

Donor HLA-C genotype has a profound impact on the clinical outcome following liver transplantation

Late allograft dysfunction is a significant problem following liver transplantation and its pathogenesis is uncertain. HLA-C is the major inhibitory ligand for killer immunoglobulin-like receptors (KIRs) that regulate the cytotoxic activity of natural killer (NK) cells. HLA-C alleles can be allocated into two groups, termed HLA-C1 and HLA-C2, based on their KIR specificity. HLA-C2 interactions are more inhibiting to NK cell activation. We studied the clinical importance of HLA-C genotype in a large liver transplant cohort and found that possession of at least one HLA-C2 allele by the donor allograft was associated with less histological evidence of chronic rejection and graft cirrhosis, a 16.2% reduction in graft loss (p = 0.003) (hazard ratio: 2.7, 95% CI 1.4-5.3) and a 13.6% improvement in patient survival (p = 0.01) (hazard ratio: 1.9, 95% CI 1.1-3.3) at 10 years. Transplantation of an HLA-C2 homozygous allograft led to a particularly striking 26.5% reduction in graft loss (p < 0.001) (hazard ratio: 7.2, 95% CI 2.2-23.0) at 10 years when compared to HLA-C1 homozygous allografts. Donor HLA-C genotype is therefore a major determinant of clinical outcome after liver transplantation and reveals the importance of NK cells in chronic rejection and graft cirrhosis. Modulation of HLA-C and KIR interactions represents an important novel approach to promote long-term graft and patient survival.

A systematic review and economic evaluation of epoetin alpha, epoetin beta and darbepoetin alpha in anaemia associated with cancer, especially that attributable to cancer treatment

OBJECTIVES

To assess the effectiveness and cost-effectiveness of epoetin alpha, epoetin beta and darbepoetin alpha (referred to collectively in this report as epo) in anaemia associated with cancer, especially that attributable to cancer treatment.

DATA SOURCES

Electronic databases were searched from 2000 (1996 in the case of darbepoetin alpha) to September 2004.

REVIEW METHODS

Using a recently published Cochrane review as the starting point, a systematic review of recent randomised controlled trials (RCTs) comparing epo with best standard was conducted. Inclusion, quality assessment and data abstraction were undertaken in duplicate. Where possible, meta-analysis was employed. The economic assessment consisted of a systematic review of past economic evaluations, an assessment of economic models submitted by the manufacturers of the three epo agents and development of a new individual sampling model (the Birmingham epo model).

RESULTS

In total 46 RCTs were included within this systematic review, 27 of which had been included in the Cochrane systematic review. All 46 trials compared epo plus supportive care for anaemia (including transfusions), with supportive care for anaemia (including transfusions), alone. Haematological response (defined as an improvement by 2 g/dl(-1)) had a relative risk of 3.4 [95% confidence interval (CI) 3.0 to 3.8, 22 RCTs] with a response rate for epo of 53%. The trial duration was most commonly 16-20 weeks. There was little statistical heterogeneity in the estimate of haematological response, and there were no important differences between the subgroups examined. Haemoglobin (Hb) change showed a weighted mean difference of 1.63 g/dl(-1) (95% CI 1.46 to 1.80) in favour of epo. Treatment with erythropoietin in patients with cancer-induced anaemia reduces the number of patients who receive a red blood cell transfusion (RBCT) by an estimated 18%. Health-related quality of life (HRQoL) data were analysed using vote counting and qualitative assessment and a positive effect was observed in favour of an improved HRQoL for patients on epo. Published information on side-effects was of poor quality. New trials provided further evidence of side-effects with epo, particularly thrombic events, but it is still unclear whether these could be accounted for by chance alone. The results of the previous Cochrane review had suggested a survival advantage for epo (HR 0.84, 95% CI 0.69 to 1.02), based on 19 RCTs. The update, based on 28 RCTs, suggests no difference (HR 1.03, 95% CI 0.88 to 1.21). Subgroup analysis suggested some explanations for this heterogeneity, but it is difficult to draw firm conclusions without access to the substantial amounts of missing or unpublished data, or more detailed results from some of the trials with heterogeneous patient populations. The conclusions are, however, broadly in line with those of a Food and Drug Administration (FDA) safety briefing, which recommended that patients with a haemoglobin above 12 g/dl(-1) should not be treated; the target rate of rise in Hb should not be too great, and further carefully conducted trials are required to determine which subgroups of patients may be harmed by the use of these products, in particular through the stimulation of tumour activity. Five published economic evaluations identified from the literature had inconsistent results, with estimates ranging from a cost per quality-adjusted life-year (QALY) under pound 10,000 through to epo being less effective and more costly than standard care. The more favourable evaluations assumed a survival advantage for epo. The three company models submitted each relied on assumed survival gains to achieve relatively low cost per QALY, from pound 13,000 to pound 28,000, but generated estimates from pound 84,000 to pound 159,000 per QALY when no survival gain was assumed. Each of these models relied on Hb levels alone driving utility, and each assumed gradual normalisation of Hb in the standard treatment arm after the end of treatment. The Birmingham epo model followed the company models in regard to the relationship between Hb levels and utility, and also assumed normalisation in the base case. With no survival gain, the incremental cost per QALY was pound 150,000, falling to pound 40,000 when the lower, more favourable, confidence interval for survival was used.

CONCLUSIONS

Epo is effective in improving haematological response and reducing RBCT requirements, and appears to have a positive effect on HRQoL. The incidence of side-effects and effects on survival remains highly uncertain. However, if there is no impact on survival, it seems highly unlikely that epo would be considered a cost-effective use of healthcare resources. The main target for further research should be improving estimates of impact on survival, initially through more detailed secondary research, such as the individual patient data meta-analysis started by the Cochrane group. Further trials may be required, and have been recommended by the FDA, although many trials are in progress, completed but unreported or awaiting mature follow-up. The Birmingham epo model developed as part of this project contains new features that improve its flexibility in exploring different scenarios; further refinement and validation would therefore be of assistance. Finally, further research to resolve uncertainty about other parameters, particularly quality of life, adverse events, and the rate of normalisation, would also be beneficial.