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.

Rapid Mechanical Ventilation Superior to Rapid Jet Ventilation for Diaphragm Motion Reduction in Radiotherapy

PURPOSE/OBJECTIVE(S)

To account for respiratory motion in radiotherapy either large target volumes are defined, or patients are instructed to breath-hold repeatedly. Alternatively, non-invasive ventilation induced regularized breathing at high frequencies may reduce motion, minimizing irradiated volumes. We quantified the motion of the right hemidiaphragm during rapid non-invasive mechanical ventilation (NI-MV) and rapid non-invasive jet ventilation (JET) to compare the effectiveness on respiratory motion.

MATERIALS/METHODS

After ethics committee approval and written informed consent, 15 healthy volunteers enrolled in this study. During a first session, they were trained being ventilated with NI-MV and JET to regularize their breathing. The ventilation frequencies under investigation included 60 breaths per minute (brpm) NI-MV (60NI-MV), and 60, 150, 250 and 400 brpm JET (60JET, 150JET, 250JET and 400JET, respectively). In a second session, ultrasound movies of 40 sec (temporal resolution 23 Hz) were acquired in the sagittal plane twice for each ventilation frequency. We quantified the magnitude of ventilation-induced rhythmic motion as the mean distance between each subsequent end-inspiration and end-expiration position of the diaphragm. Also, we determined the overall maximum motion of the diaphragm over the 40 sec measurement. We tested for statistically significant differences between median rhythmic motion and overall maximum motion during all frequencies (paired Wilcoxon's tests (n = 10); corrected p-value for multiple testing (p = 0.05/N)).

RESULTS

All volunteers were successfully trained. There were no significant differences between repeated measurements of each ventilation frequency; hence we pooled the data. We found that 60NI-MV resulted in significantly smaller rhythmic motion compared to 60JET (median 5.0 mm and 8.9 mm respectively; p<0.001). Higher ventilation frequencies with JET decreased the median rhythmic motion magnitude (2.3 mm, 1.0 mm and 0.5 mm at 150JET, 250JET and 400JET respectively; p<0.001). However, during these higher frequencies the smaller rhythmic motion magnitudes did not result in smaller overall maximum motion compared to 60NI-MV. The median overall motion was 17.2 mm, 15.8 mm and 13.4 mm for 150JET, 250JET and 400JET respectively (p<0.005 only between 60JET and 400JET). The overall maximum motion during 60NI-MV was significantly smaller compared to 60JET (12.3 mm and 24.1 mm respectively; p<0.001). The US movies clearly showed that volunteers superimposed spontaneous breathing on top of JET. Finally, volunteers indicated NI-MV to be more comfortable than JET.

CONCLUSION

Mechanical ventilation at 60 brpm maximally reduced the overall motion of the right hemidiaphragm and was more comfortable than jet ventilation. Therefore, mechanical ventilation appears to be superior to control respiratory motion for radiotherapy.

Anticipating the unimaginable: Heat Health Warning Systems in Europe and Australia

Background

It has long been a maxim of climate and health research that heatwaves kill more people than all other natural disasters combined. Heatwave frequency, severity and duration have increased as climate change intensifies, and recorded temperatures during recent heat events now regularly surpass previous worst-case projections. Temperate zones, between 40°-60° north or south of the Equator, are particularly vulnerable, as small variations in mean temperature can trigger large-scale increases in morbidity, mortality and concomitant health service strain. Heat Health Warning Systems (HHWSs) combine temperature forecasts with public health actions to mitigate these impacts. However, in the absence of a consensus definition of heatwaves multiple systems have developed, and comparative analysis of the effectiveness of different HHWS and their interventions are hindered by lack of a common threshold metric for defining and predicting heatwave severity.

Methods

This paper provides a comprehensive review of current HHWS and their evidence base in temperate zones in Europe, the United Kingdom and Australia - contiguous landmasses containing multiple jurisdictions with high heterogeneity in local HHWSs, in which single heatwave events trigger vastly different public health responses. A systematic review of available published and grey literature was undertaken to generate a schema of HHWSs in these zones. Results were then narrowed to review and synthesise evidence for each, with a focus on threshold effectiveness in predicting health impacts.

Results and conclusions

Over twenty distinct HHWS are reviewed, with substantial variation in the evidence for their effectiveness. We make the case for a unified threshold metric for defining heatwaves, to facilitate research and identify warning systems which accurately predict health impacts and effectively communicate risk.

Key messages

• Lack of definitional consensus and heterogeneity in threshold metrics hinders comparison of Heat Health Warning Systems.

• Accurate prediction and rapid communication of heat risk is crucial to prevent health impacts of heatwaves.

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.

POS0965 MAGNETIC RESONANCE ENTEROGRAPHY AS A SCREENING TOOL FOR AXIAL SPONDYLOARTHRITIS IN CROHN’S DISEASE: A PROSPECTIVE SINGLE-CENTER CROSS-SECTIONAL OBSERVATIONAL STUDY USING MRE SCREENING FOLLOWED BY CLINICAL ASSESSMENT (ProSpA-CD)

Background

Patients with inflammatory bowel disease (IBD) have an excess burden of axial spondyloarthritis (axSpA) (1), but currently there are no reliable screening tools available. Magnetic resonance enterography (MRE) is an oral contrast MRI of the small bowel used to aid the diagnosis of Crohn’s disease (CD) (2). MRE also captures the sacroiliac joints (SIJs) but the radiological assessment of this is often overlooked. MRE scans therefore contain potentially valuable unreported data, which could be used to screen for axSpA in CD patients.

Objectives

To determine: (i) the validity, sensitivity, specificity and area under the receiver operating characteristic (ROC) curve (AUC) of MRE as a screening tool for axSpA in CD, using dedicated axial MRI scans with clinical assessment as the gold standard; (ii) the proportion of patients with evidence of axSpA on MRE who fulfill the 2009 Assessment of Spondyloarthritis International Society (ASAS) criteria for axSpA; (iii) whether the presence of extra-intestinal manifestations (EIMs) or CD location can predict the occurrence of axSpA in CD.

Methods

ProSpA-CD was a pair of linked prospective observational studies conducted at a large secondary care university hospital in the UK. In ProSpA-CD-Screen, patients who had undergone MRE between 2015-2019 were assessed for eligibility. The consenting participants‘ MRE images were evaluated by a rheumatologist and a radiologist, using a scoring system for evidence of axSpA. Participants with evidence of axSpA and a control group of participants without evidence of axSpA were invited to participate in ProSpA-CD-Assess, in which the performance of MRE as a screening test was assessed against a gold standard of clinical assessment, serological testing and dedicated MRI of the spine and pelvis of each participant. ROC curve and logistic regression analyses were performed.

Results

A total of 1344 MRE scans were performed between 2015-2019, of which 501 eligible patients were identified. For ProSpA-CD-Screen, 259 participants were recruited. MRE SIJ abnormalities were identified in 94/259 participants and from these, 90 cases were recruited to ProSpA-CD-Assess. For the control group, 71/165 participants with normal SIJs were recruited to ProSpA-CD-Assess (total cases + controls = 161). A clinical diagnosis of axSpA was made in 41/161 (25.47%) participants, of which 25/161 (15.53%) fulfilled ASAS criteria. We constructed a ROC curve to assess test performance using different thresholds on the MRE scoring system. The optimum threshold corresponded to a sensitivity of 0.60 (95%CI 0.39, 0.79) and specificity of 0.85 (95%CI 0.78, 0.91) for MRE as a screening tool for axSpA (ASAS criteria) with an AUC value of 0.78 (95%CI 0.65, 0.86, p<0.05). We did not find a significant association between axSpA and CD location. Multivariable logistic regression demonstrated significant associations between axSpA (ASAS criteria) and inflammatory back pain (OR 11.03; 95%CI 2.53, 48.10; p<0.05), HLA B27 (OR 9.94; 95%CI 1.84, 53.87; p<0.05), history of dactylitis (OR 51.01; 95%CI 1.07, 2423.90; p<0.05) and plantar fasciitis (OR 9.08; 95%CI 1.30, 63.55; p<0.05).

Conclusion

We have shown that MRE as a screening tool for axSpA in a cohort of CD patients has good specificity, but poor sensitivity, suggesting that its use as a screening tool is limited. There was no significant association between axSpA and CD location or CD EIMs.

References

[1]Garber A, Regueiro M. Extraintestinal Manifestations of Inflammatory Bowel Disease: Epidemiology, Etiopathogenesis, and Management. Curr Gastroenterol Rep. 2019;21(7):31.

[2]Rimola J, Ordas I, Rodriguez S, Garcia-Bosch O, Aceituno M, Llach J, et al. Magnetic resonance imaging for evaluation of Crohn’s disease: validation of parameters of severity and quantitative index of activity. Inflamm Bowel Dis. 2011;17(8):1759-68.

Figure 1.

MRE score ROC curve for participants fulfilling ASAS criteria for axial spondyloarthritis.

Acknowledgements

Acknowledgement is given to Dr Beverly Ng, Katherine Hodges and CARE for their contribution to this study.

Disclosure of Interests

Jobie Evans Grant/research support from: Clinical study (ProSpA-CD) funded by Merck, Sharpe and Dohme (MSD), Tim Raine: None declared, Scott McDonald: None declared, Ken Poole: None declared, Richard Samworth: None declared, Philippe Riede: None declared, Elliott Rees: None declared, Simona D’Amore: None declared, Miles Parkes: None declared, Deepak Jadon Grant/research support from: Clinical study (ProSpA-CD) funded by Merck, Sharpe and Dohme (MSD)

Distinguishing synaptic vesicle precursor navigation of microtubule ends with a single rate constant model

Axonal motor driven cargo utilizes the microtubule cytoskeleton in order to direct cargo, such as synaptic vesicle precursors (SVP), to where they are needed. This transport requires vesicles to travel up to microns in distance. It has recently been observed that finite microtubule lengths can act as roadblocks inhibiting SVP and increasing the time required for transport. SVPs reach the end of a microtubule and pause until they can navigate to a neighboring microtubule in order to continue transport. The mechanism(s) by which axonal SVPs navigate the end of a microtubule in order to continue mobility is unknown. In this manuscript we model experimentally observed vesicle pausing at microtubule ends in C. elegans. We show that a single rate-constant model reproduces the time SVPs pause at MT-ends. This model is based on the time an SVP must detach from its current microtubule and re-attach to a neighboring microtubule. We show that vesicle pause times are different for anterograde and retrograde motion, suggesting that vesicles utilize different proteins at plus and minus end sites. Last, we show that vesicles do not likely utilize a tug-of-war like mechanism and reverse direction in order to navigate microtubule ends.

Schedule feasibility and workflow for additive manufacturing of titanium plates for ranioplasty in canine skull tumors

Background

Additive manufacturing has allowed for the creation of a patient-specific custom solution that can resolve many of the limitations previously reported for canine cranioplasty. The purpose of this pilot study was to determine the schedule feasibility and workflow in manufacturing patient-specific titanium implants for canines undergoing cranioplasty immediately following craniectomy.

Results

Computed tomography scans from patients with tumors of the skull were considered and 3 cases were selected. Images were imported into a DICOM image processing software and tumor margins were determined based on agreement between a board-certified veterinary radiologist and veterinary surgical oncologist. Virtual surgical planning was performed and a bone safety margin was selected. A defect was created to simulate the planned intraoperative defect. Stereolithography format files of the skulls were then imported into a plate design software. In collaboration with a medical solution centre, a custom titanium plate was designed with the input of an applications engineer and veterinary surgery oncologist. Plates were printed in titanium and post-processed at the solution centre. Total planning time was approximately 2 h with a manufacturing time of 2 weeks.

Conclusions

Based on the findings of this study, with access to an advanced 3D metal printing medical solution centre that can provide advanced software and printing, patient-specific additive manufactured titanium implants can be planned, created, processed, shipped and sterilized for patient use within a 3-week turnaround.

Vaccine Prevention of Paediatric Chronic Lung Disease: Targeting Haemophilus

Background

Chronic Suppurative Lung Disease (CSLD) is an emerging term encompassing a spectrum of chronic childhood respiratory disease. Characterised by early and severe infections and recurrent exacerbations, it is associated with progressive deterioration in lung function and quality of life. CSLD is highly unequally distributed and largely preventable, and is a major contributor to the global burden of chronic paediatric respiratory disease. Relatively few pathogens comprise the main culprit organisms identified in the aetiology of CSLD, over which Non-Typeable Haemophilus influenzae (NTHi) predominates.

Methods

We review developments that establish the role of NTHi in disease progression, focusing on high-risk population subgroups with an established CSLD burden. We consider current studies examining the role of prenatal NTHi and pneumococcal vaccination in preventing CSLD through reducing infections in high-risk populations, and discuss current directions in future research, including the need for precise identification of the pulmonary microbiome in CSLD.

Results

Early, repeated NTHi infections are clearly implicated in the aetiology of CLSD. Early results of current studies indicate NTHi vaccination may reduce the frequency of causal infections in high-risk groups. Clinical and immunological data show vaccination also reduces frequency of exacerbations and antibiotic usage in CSLD.

Conclusions

We provide the first clinical and immunological data for H. influenzae vaccination in children with CSLD. Targeted vaccination strategies may prevent CSLD establishment, slow progression, and potentially reduce morbidity, healthcare presentations and antibiotic consumption. This implicates vaccination as a potential aid in both antimicrobial stewardship and prevention of chronic disease. In the face of threats posed to health systems by antimicrobial resistance and the growing burden of chronic disease, vaccination is again emerging as a uniquely powerful public health tool.

Key messages

Hi vaccination can reduce infective exacerbations and antibiotic use in children with CSL. Vaccines may have a role in preventing chronic disease progression and reducing antibiotic reliance.

Patients with perianal Crohn's fistulas experience delays in accessing anti-TNF therapy due to slow recognition, diagnosis and integration of specialist services: lessons learned from three referral centres

AIM

Crohn's anal fistula should be managed by a multidisciplinary team. There is no clearly defined 'patient pathway' from presentation to treatment. The aim of this study was to describe the patient route from presentation with symptomatic Crohn's anal fistula to starting anti-tumour necrosis factor (anti-TNF) therapy.

METHOD

Case note review was undertaken at three hospitals with established inflammatory bowel disease services. Patients with Crohn's anal fistula presenting between 2010 and 2015 were identified through clinical coding and local databases. Baseline demographics were captured. Patient records were interrogated to identify route of access, and clinical contacts during the patient pathway.

RESULTS

Seventy-nine patients were included in the study, of whom 54 (68%) had an established diagnosis of Crohn's disease (CD). Median time from presentation to anti-TNF therapy was 204 days (174 vs 365 days for existing and new diagnosis of CD, respectively; P = 0.019). The mean number of surgical outpatient attendances, operations and MRI scans per patient was 1.03, 1.71 and 1.03, respectively. Patients attended a mean of 1.49 medical clinics. Seton insertion was the most common procedure, accounting for 48.6% of all operations. Where care episodes ('clinical events per 30 days') were infrequent this correlated with prolongation of the pathway (r = -0.87; P < 0.01).

CONCLUSION

This study highlights two key challenges in the treatment pathway: (i) delays in diagnosis of underlying CD in patients with anal fistula and (ii) the pathway to anti-TNF therapy is long, suggesting issues with service design and delivery. These should be addressed to improve patient experience and outcome.

Infliximab and adalimumab drug levels in Crohn's disease: contrasting associations with disease activity and influencing factors

BACKGROUND

Discriminative drug level thresholds for disease activity endpoints in patients with Crohn's disease. have been consistently demonstrated with infliximab, but not adalimumab.

AIMS

To identify threshold concentrations for infliximab and adalimumab in Crohn's disease according to different disease endpoints, and factors that influence drug levels.

METHODS

We performed a cross-sectional service evaluation of patients receiving maintenance infliximab or adalimumab for Crohn's disease. Serum drug levels were at trough for infliximab and at any time point for adalimumab. Endpoints included Harvey-Bradshaw index, C-reactive protein and faecal calprotectin. 6-tioguanine nucleotide (TGN) concentrations were measured in patients treated with thiopurines.

RESULTS

A total of 191 patients (96 infliximab, 95 adalimumab) were included. Differences in infliximab levels were observed for clinical (P=.081) and biochemical remission (P=.003) and faecal calprotectin normalisation (P<.0001) with corresponding thresholds identified on ROC analysis of 1.5, 3.4 and 5.7 μg/mL. Adalimumab levels were similar between active disease and remission regardless of the endpoint assessed. Modelling identified that higher infliximab dose, body mass index and colonic disease independently accounted for 31% of the variation in infliximab levels, and weekly dosing, albumin and weight accounted for 23% of variation in adalimumab levels. TGN levels did not correlate with drug levels.

CONCLUSIONS

Infliximab drug levels are associated with the depth of response/remission in patients with Crohn's disease, but no such relationship was observed for adalimumab. More data are needed to explain the variation in drug levels.

Prognostic factors for musculoskeletal injury identified through medical screening and training load monitoring in professional football (soccer): a systematic review

OBJECTIVES

To identify prognostic factors and models for spinal and lower extremity injuries in adult professional/elite football players from medical screening and training load monitoring processes.

METHODS

The MEDLINE, AMED, EMBASE, CINAHL Plus, SPORTDiscus electronic bibliographic databases and the Cochrane Database of Systematic Reviews were searched from inception to July 2016. Searches were limited to original research, published in peer reviewed journals of any language. The Quality in Prognostic Studies (QUIPS) tool was used for appraisal and the modified GRADE approach was used for synthesis. Prospective and retrospective cohort study designs of spinal and lower extremity injury incidence were found from populations of adult professional/elite football players, between 16 and 40 years. Non-football or mixed sports were excluded.

RESULTS

858 manuscripts were identified. Removing duplications left 551 studies, which were screened for eligibility by title and abstract. Of these, 531 studies were not eligible and were excluded. The full text of the remaining 20 studies were obtained; a further 10 studies were excluded. 10 studies were included for appraisal and analysis, for 3344 participants.

CONCLUSIONS

Due to the paucity and heterogeneity of the literature, and shortcomings in methodology and reporting, the evidence is of very low or low quality and therefore cannot be deemed robust enough to suggest conclusive prognostic factors for all lower limb musculoskeletal injury outcomes identified. No studies were identified that examined spinal injury outcomes or prognostic models.

Flight Lieutenant Peach's observations on Burning Feet Syndrome in Far Eastern Prisoners of War 1942-45

INTRODUCTION

'Burning Feet Syndrome' affected up to one third of Far Eastern Prisoners of War in World War 2. Recently discovered medical records, produced by RAF Medical Officer Nowell Peach whilst in captivity, are the first to detail neurological examinations of patients with this condition.

METHODS

The 54 sets of case notes produced at the time were analysed using modern diagnostic criteria to determine if the syndrome can be retrospectively classed as neuropathic pain.

RESULTS

With a history of severe malnutrition raising the possibility of a peripheral polyneuropathy, and a neuroanatomically plausible pain distribution, this analysis showed that Burning Feet Syndrome can now be described as a 'possible' neuropathic pain syndrome.

CONCLUSION

After 70 years, the data painstakingly gathered under the worst of circumstances have proved to be of interest and value in modern diagnostics of neuropathic pain.

A protein-truncating R179X variant in RNF186 confers protection against ulcerative colitis

Protein-truncating variants protective against human disease provide in vivo validation of therapeutic targets. Here we used targeted sequencing to conduct a search for protein-truncating variants conferring protection against inflammatory bowel disease exploiting knowledge of common variants associated with the same disease. Through replication genotyping and imputation we found that a predicted protein-truncating variant (rs36095412, p.R179X, genotyped in 11,148 ulcerative colitis patients and 295,446 controls, MAF=up to 0.78%) in RNF186, a single-exon ring finger E3 ligase with strong colonic expression, protects against ulcerative colitis (overall P=6.89 × 10(-7), odds ratio=0.30). We further demonstrate that the truncated protein exhibits reduced expression and altered subcellular localization, suggesting the protective mechanism may reside in the loss of an interaction or function via mislocalization and/or loss of an essential transmembrane domain.

Relapse after withdrawal from anti-TNF therapy for inflammatory bowel disease: an observational study, plus systematic review and meta-analysis

BACKGROUND

Infliximab and adalimumab have established roles in inflammatory bowel disease (IBD) therapy. UK regulators mandate reassessment after 12 months' anti-TNF therapy for IBD, with consideration of treatment withdrawal. There is a need for more data to establish the relapse rates following treatment cessation.

AIM

To establish outcomes following anti-TNF withdrawal for sustained remission using new data from a large UK cohort, and assimilation of all available literature for systematic review and meta-analysis.

METHODS

A retrospective observational study was performed on 166 patients with IBD (146 with Crohn's disease (CD) and 20 with ulcerative colitis [UC) and IBD unclassified (IBDU)] withdrawn from anti-TNF for sustained remission. Meta-analysis was undertaken of all published studies incorporating 11 further cohorts totalling 746 patients (624 CD, 122 UC).

RESULTS

Relapse rates in the UK cohort were 36% by 1 year and 56% by 2 years for CD, and 42% by 1 year and 47% by 2 years for UC/IBDU. Increased relapse risk in CD was associated with age at diagnosis [hazard ratio (HR) 2.78 for age <22 years], white cell count (HR 3.22 for >5.25 × 10⁹ /L) and faecal calprotectin (HR 2.95 for >50 μg/g) at drug withdrawal. Neither continued immunomodulators nor endoscopic remission were predictors. In the meta-analysis, estimated 1-year relapse rates were 39% and 35% for CD and UC/IBDU respectively. Retreatment with anti-TNF was successful in 88% for CD and 76% UC/IBDU.

CONCLUSIONS

Assimilation of all available data reveals remarkable homogeneity. Approximately one-third of patients with IBD flare within 12 months of withdrawal of anti-TNF therapy for sustained remission.

Thiopurine withdrawal during sustained clinical remission in inflammatory bowel disease: relapse and recapture rates, with predictive factors in 237 patients

BACKGROUND

Thiopurines (azathioprine and mercaptopurine) remain integral to most medical strategies for maintaining remission in Crohn's disease (CD) and ulcerative colitis (UC). Indefinite use of these drugs is tempered by long-term risks. While clinical relapse is noted frequently following drug withdrawal, there are few published data on predictive factors.

AIM

To investigate the success of planned thiopurine withdrawal in patients in sustained clinical remission to identify rates and predictors of relapse.

METHODS

This was a multicentre retrospective cohort study from 11 centres across the UK. Patients included had a definitive diagnosis of IBD, continuous thiopurine use ≥3 years and withdrawal when in sustained clinical remission. All patients had a minimum of 12 months follow-up post drug withdrawal. Primary and secondary end points were relapse at 12 and 24 months respectively.

RESULTS

237 patients were included in the study (129 CD; 108 UC). Median duration of thiopurine use prior to withdrawal was 6.0 years (interquartile range 4.4-8.4). At follow-up, moderate/severe relapse was observed in 23% CD and 12% UC patients at 12 months, 39% CD and 26% UC at 24 months. Relapse rate at 12 months was significantly higher in CD than UC (P = 0.035). Elevated CRP at withdrawal was associated with higher relapse rates at 12 months for CD (P = 0.005), while an elevated white cell count was predictive at 12 months for UC (P = 0.007).

CONCLUSION

Thiopurine withdrawal in the context of sustained remission is associated with a 1-year moderate-to-severe relapse rate of 23% in Crohn's disease and 12% in ulcerative colitis.

New IBD genetics: common pathways with other diseases

Complex disease genetics has been revolutionised in recent years by the advent of genome-wide association (GWA) studies. The chronic inflammatory bowel diseases (IBDs), Crohn's disease and ulcerative colitis have seen notable successes culminating in the discovery of 99 published susceptibility loci/genes (71 Crohn's disease; 47 ulcerative colitis) to date. Approximately one-third of loci described confer susceptibility to both Crohn's disease and ulcerative colitis. Amongst these are multiple genes involved in IL23/Th17 signalling (IL23R, IL12B, JAK2, TYK2 and STAT3), IL10, IL1R2, REL, CARD9, NKX2.3, ICOSLG, PRDM1, SMAD3 and ORMDL3. The evolving genetic architecture of IBD has furthered our understanding of disease pathogenesis. For Crohn's disease, defective processing of intracellular bacteria has become a central theme, following gene discoveries in autophagy and innate immunity (associations with NOD2, IRGM, ATG16L1 are specific to Crohn's disease). Genetic evidence has also demonstrated the importance of barrier function to the development of ulcerative colitis (HNF4A, LAMB1, CDH1 and GNA12). However, when the data are analysed in more detail, deeper themes emerge including the shared susceptibility seen with other diseases. Many immune-mediated diseases overlap in this respect, paralleling the reported epidemiological evidence. However, in several cases the reported shared susceptibility appears at odds with the clinical picture. Examples include both type 1 and type 2 diabetes mellitus. In this review we will detail the presently available data on the genetic overlap between IBD and other diseases. The discussion will be informed by the epidemiological data in the published literature and the implications for pathogenesis and therapy will be outlined. This arena will move forwards very quickly in the next few years. Ultimately, we anticipate that these genetic insights will transform the landscape of common complex diseases such as IBD.

Colorectal cancer detection: time to abandon barium enema?

OBJECTIVES

To assess the sensitivity of double contrast barium enema (DCBE) for diagnosing colorectal cancer (CRC).

DESIGN

Retrospective evaluation of DCBE performed in the 2 years prior to diagnosis of CRC.

SETTING

Teaching hospital in Cambridge, UK.

PATIENTS

1310 consecutive cases of CRC identified from cancer registry data.

INTERVENTIONS

DCBE and colonoscopy.

MAIN OUTCOME MEASURES

Sensitivity of DCBE for diagnosing CRC.

RESULTS

215 patients had undergone a DCBE within the 2 years prior to diagnosis with CRC. After excluding those reported as inadequate, 37 of these were reported as normal, giving a sensitivity of 83% (81-85%).

CONCLUSIONS

The performance of DCBE is inadequate for the exclusion of CRC. Expansion of colonoscopy and CT colonography capacity is urgently required nationally so that DCBE can finally be abandoned as a firstline test in patients at risk of CRC.

Use of sirolimus (rapamycin) to treat refractory Crohn's disease

We present the case of a 37-year-old woman with severe refractory colonic and perianal Crohn's disease who had lost response to second-line, steroid-sparing treatments azathioprine, methotrexate and infliximab. For many such patients extensive surgery has often been considered the only option. New insights provided by the results of genome-wide association scanning in Crohn's disease highlight autophagy, a cellular process implicated in the clearance of intracellular bacteria, as a key process in Crohn's disease pathogeneses. Sirolimus (rapamycin) is a drug used to upregulate autophagy in cell culture in the laboratory, and in clinical practice to prevent rejection following organ transplantation due to independent immunosuppressive action. Our patient was treated with sirolimus for 6 months at a dose that maintained serum trough levels of 5 ng/ml. There was marked and sustained improvement in Crohn's disease symptoms with the Harvey-Bradshaw index falling from 13 to 3, in serum markers of inflammation (C-reactive protein fell from 79 to 2) and endoscopic appearance. This is the first reported case of the use of sirolimus to treat Crohn's disease.

Gender-stratified analysis of DLG5 R30Q in 4707 patients with Crohn disease and 4973 controls from 12 Caucasian cohorts

BACKGROUND

DLG5 p.R30Q has been reported to be associated with Crohn disease (CD), but this association has not been replicated in most studies. A recent analysis of gender-stratified data from two case-control studies and two population cohorts found an association of DLG5 30Q with increased risk of CD in men but not in women and found differences between 30Q population frequencies for males and females. Male-female differences in population allele frequencies and male-specific risk could explain the difficulty in replicating the association with CD.

METHODS

DLG5 R30Q genotype data were collected for patients with CD and controls from 11 studies that did not include gender-stratified allele counts in their published reports and tested for male-female frequency differences in controls and for case-control frequency differences in men and in women.

RESULTS

The data showed no male-female allele frequency differences in controls. An exact conditional test gave marginal evidence that 30Q is associated with decreased risk of CD in women (p = 0.049, OR = 0.87, 95% CI 0.77 to 1.00). There was also a trend towards reduced 30Q frequencies in male patients with CD compared with male controls, but this was not significant at the 0.05 level (p = 0.058, OR = 0.87, 95% CI 0.74 to 1.01). When data from this study were combined with previously published, gender-stratified data, the 30Q allele was found to be associated with decreased risk of CD in women (p = 0.010, OR = 0.86, 95% CI 0.76 to 0.97), but not in men.

CONCLUSION

DLG5 30Q is associated with a small reduction in risk of CD in women.

A randomized, double-blind, placebo-controlled trial of lenalidomide in the treatment of moderately severe active Crohn's disease

BACKGROUND

Therapy targeted at tumour necrosis factor-alpha has an established role in Crohn's disease. Lenalidomide, an analogue of thalidomide, is an oral immunomodulatory agent with powerful antitumour necrosis factor-alpha properties. It is licensed for myeloma and myelodysplastic syndrome. Based upon reports of thalidomide efficacy, lenalidomide was evaluated in Crohn's disease.

AIM

To evaluate the efficacy and safety of lenalidomide in subjects with moderately severe active Crohn's disease.

METHODS

In a multicentre, double-blind, placebo-controlled parallel group study 89 subjects were randomized to lenalidomide 25 mg daily, 5 mg daily or placebo. Subjects were treated for 12 weeks. The primary end point was a 70-point reduction in Crohn's Disease Activity Index.

RESULTS

The overall clinical response rate was not significantly different between the three groups: lenalidomide 25 mg 26%, lenalidomide 5 mg 48% and placebo 39%. Lenalidomide was generally well tolerated with only one serious adverse event, a deep vein thrombosis, being attributed to treatment.

CONCLUSION

Lenalidomide, an oral agent with antitumour necrosis factor-alpha properties, was not effective in active Crohn's disease in contrast to reports of benefit from thalidomide. The reasons for this lack of efficacy are speculative, other physiological activities may offset its action on inflammatory cytokines, or its antitumour necrosis factor-alpha action without apoptosis may be insufficient for activity in Crohn's disease.

Analysis of the BTNL2 truncating splice site mutation in tuberculosis, leprosy and Crohn's disease

The region on chromosome 6 encoding the major histocompatibility complex (MHC) is associated with a number of autoimmune and infectious diseases. Primary susceptibility to many of these has been localized to a region containing the human leukocyte antigen (HLA)-DR and -DQ genes. A recent study of sarcoidosis has provided evidence of an independent effect, associated with a truncating single nucleotide polymorphism (SNP) of a nearby gene, BTNL2. This gene may encode an immune receptor involved in costimulation. Sarcoidosis, tuberculoid leprosy, tuberculosis (TB) and Crohn's disease all have similar immunological features, including a Th1 response with granuloma formation. In addition mycobacteria have been identified or suggested to be causative pathogens in such conditions. We genotyped the truncating BTNL2 SNP in 92 TB and 72 leprosy families from Brazil and carried out family-based association studies. We could not find evidence of overtransmission of the truncating allele in TB. There was an association with susceptibility to leprosy (P=0.04), however, this is most likely due to linkage disequilibrium with HLA-DR. We also genotyped 476 UK Caucasian cases of Crohn's disease with 760 geographically matched controls and found no evidence of a disease association. We conclude that the truncating BTNL2 SNP is not important in this group of Th1 dominated granulomatous diseases.

Evidence for association of OCTN genes and IBD5 with ulcerative colitis

BACKGROUND AND AIMS

Genetic association between Crohn's disease (CD) and OCTN1 (SLC22A4) C1672T/OCTN2 (SLC22A5) G-207C variants in IBD5 has recently been reported. These genes encode solute carriers and the association was suggested to be distinct from the background IBD5 risk haplotype. There have been conflicting reports of the association between markers in the IBD5 region and ulcerative colitis (UC) and interaction (epistasis) between this locus and CARD15. Our aim was to ascertain the contribution of OCTN variants to UC and CD in a large independent UK dataset, to seek genetic evidence that the OCTN association is distinct from the IBD5 risk haplotype and to identify interactions between the IBD5 and CARD15 loci.

METHODS

A total of 1104 unrelated Caucasian subjects with inflammatory bowel disease (IBD) (496 CD, 512 UC, 96 indeterminate) and 750 ethnically matched controls were genotyped for three single nucleotide polymorphisms (SNPs) in the CD associated genes (OCTN1+1672, OCTN2-207, and IGR2230), and two flanking IBD5 tagging SNPs, IGR2096 and IGR3096. Data were analysed by logistic regression methods within STATA.

RESULTS

OCTN variants were as strongly associated with UC and IBD overall as they were with CD (p = 0.0001; OR 1.3 (95% confidence interval 1.1-1.5)). OCTN variants were in tight linkage disequilibrium with the extended IBD5 risk haplotype D' 0.79 and 0.88, and r2 = 0.62 and 0.72 for IGR2096 and 3096, respectively. There was no deviation from a multiplicative model of interaction between CARD15 and IBD5 on the penetrance scale.

CONCLUSIONS

The OCTN variants were associated with susceptibility to IBD overall. The effect was equally strong in UC and CD. Although OCTN variants may account for the increased risk of IBD associated with IBD5, a role for other candidate genes within this extended haplotype was not excluded. There was no statistical evidence of interaction between CARD15 and either OCTN or IBD5 variants in susceptibility to IBD.

Systematic review: the use of mesalazine in inflammatory bowel disease

BACKGROUND

Mesalazine is among the medications most commonly prescribed by gastroenterologists, having to a large extent superseded sulfasalazine (sulphasalazine). However, there are still a number of aspects regarding its use which provoke debate and controversy.

AIM

To provide a systematic assessment of the evidence for the use of mesalazine in ulcerative colitis and Crohn's disease.

METHODS

References were identified using PubMed database. Additional references were identified with related article searches.

RESULTS

Mesalazine has a clear role in the maintenance of remission in ulcerative colitis and management of mild to moderately active disease, although the efficacy of topical preparations or combined topical and oral is clearly superior to oral alone. Evidence that increasing the dose of oral mesalazine improves efficacy is not clear-cut. The benefits of mesalazine in the management of acute Crohn's disease and the maintenance of remission are questionable and alternative treatments are usually more appropriate. Emerging evidence suggests that maintenance mesalazine reduces the risk of neoplastic progression in chronic ulcerative colitis. Compliance with therapy is thus important, as is an understanding of individuals most likely to default on this.

CONCLUSION

Evidence for a beneficial effect of mesalazine is largely confined to the management of ulcerative colitis.

Human keratin 8 mutations that disturb filament assembly observed in inflammatory bowel disease patients

We have identified miss-sense mutations in keratin 8 in a subset of patients with inflammatory bowel disease (Crohn disease and ulcerative colitis). Inflammatory bowel diseases are a group of disorders that are polygenic in origin and involve intestinal epithelial breakdown. We investigated the possibility that these keratin mutations might contribute to the course of the disease by adversely affecting the keratin filament network that provides mechanical support to cells in epithelia. The mutations (Gly62 to Cys, Ile63 to Val and Lys464 to Asn) all lie outside the major mutation hotspots associated with severe disease in epidermal keratins, but using a combination of in vitro and cell culture assays we show that they all have detrimental effects on K8/K18 filament assembly in vitro and in cultured cells. The G62C mutation also gives rise to homodimer formation on oxidative stress to cultured intestinal epithelial cells, and homodimers are known to be polymerization incompetent. Impaired keratin assembly resulting from the K8 mutations found in some inflammatory bowel disease patients would be predicted to affect the maintenance and re-establishment of mechanical resilience in vivo, as required during keratin cytoskeleton remodeling in cell division and differentiation, which may lead to epithelial fragility in the gut. Simple epithelial keratins may thus be considered as candidates for genes contributing to a risk of inflammatory bowel disease.

Mobilisation of enterocyte fat stores by oral glucose in humans

BACKGROUND AND AIMS

When a high fat oral load is followed several hours later by further ingestion of nutrients, there is an early postprandial peak in plasma triacylglycerol (TG). The aim of this study was to investigate the location and release of lipid from within the gastrointestinal tract.

METHODS

Ten healthy patients undergoing oesopho-gastro-duodenoscopy (OGD) were recruited. At t=0, all patients consumed a 50 g fat emulsion and at t=5 hours they consumed either water or a 38 g glucose solution. OGD was performed at t=6 hours and jejunal biopsy samples were evaluated for fat storage. A subgroup of five subjects then underwent a parallel metabolic study in which postprandial lipid and hormone measurements were taken during an identical two meal protocol.

RESULTS

Following oral fat at t=0, samples from patients that had subsequently ingested glucose exhibited significantly less staining for lipid within the mucosa and submucosa of the jejunum than was evident in patients that had consumed only water (p=0.028). There was also less lipid storage within the cytoplasm of enterocytes (p=0.005) following oral glucose. During the metabolic study, oral glucose consumed five hours after oral fat resulted in a postprandial peak in plasma TG, chylomicron-TG, and apolipoprotein B48 concentration compared with oral water.

CONCLUSION

After a fat load, fat is retained within the jejunal tissue and released into plasma following glucose ingestion, resulting in a peak in chylomicron-TG which has been implicated in the pathogenesis of atherosclerosis.

Do steroids help jaundice caused by primary sclerosing cholangitis?

The management of jaundice in patients with primary sclerosing cholangitis (PSC) is clinically challenging. In patients in whom the recognized precipitants for jaundice have been excluded, the outlook is uncertain at best. Some improve spontaneously, but the only treatment demonstrated to be effective is liver transplantation--which may not always be appropriate. We report three cases of jaundice in patients with PSC in whom corticosteroid therapy appeared to be beneficial.

Review article: the management of severe Crohn's disease

The treatment of severe and active Crohn's disease is currently based on immunosuppression, but also involves the management of nutrition, appropriate selection of patients for surgery, and maintenance of remission in the long term. Corticosteroids remain the drug of the first choice, particularly in the acute setting. However, there is evolving understanding of the role of other immunosuppressants and immune modifiers, as major concerns regarding side-effects and efficacy of steroids in the medium to long-term drive the search for alternatives.

Evidence for inflammatory bowel disease of a susceptibility locus on the X chromosome

BACKGROUND & AIMS

The technique of genomewide scanning has been applied successfully in inflammatory bowel disease (IBD). A number of putative susceptibility loci have been identified through genomewide searches including replicated regions of linkage on chromosomes 12, 16, 6 (the HLA region), and 14. We have investigated the contribution of the X chromosome in 145 Belgian affected relative pairs.

METHODS

In the first stage of the study, 79 (68 CD, 11 mixed) sibling pairs were genotyped at 12 microsatellite markers covering the X chromosome. In the second stage, 10 additional markers in the X-pericentromeric region were studied in the families involved in stage 1 together with 62 additional families (52 sibling pairs, 14 second-degree relative pairs).

RESULTS

In the first stage, evidence for linkage was found over a 30-cM pericentromeric region spanning dXs991, dXs990, and dXs8096 (multipoint maximum LOD score in the CD subgroup, 2.5; P = 0.0003). The remainder of the X chromosome was excluded (exclusion under LOD-2) for a locus with lambda(s) = 2. Fine mapping in the second stage confirmed linkage, and narrowed and shifted the linked region to Xq21.3 around dXs1203 (nonparametric linkage [NPL], 2.90; P = 0.0017). The NPL-1 interval around the linkage peak comprises 19.7 cM.

CONCLUSIONS

These data provide suggestive evidence for the presence and chromosomal location of an X-linked susceptibility gene in IBD.

Exclusion of linkage of Crohn's disease to previously reported regions on chromosomes 12, 7, and 3 in the Belgian population indicates genetic heterogeneity

Susceptibility to inflammatory bowel disease (IBD) is significantly determined by genetic factors. Linkage data from genome-wide searches have identified regions on chromosomes 16, 12, 7, and 3. Our goal was to replicate these four regions in a Belgian population of IBD families. Fifty-four IBD families were studied (47 with Crohn's disease [CD] and 7 with mixed CD and ulcerative colitis, containing 79 affected sibpairs (68 CD only, 11 mixed) for the regions previously implicated to chromosomes 16, 12, 7, and 3. In this study, no evidence for linkage was found on any of the four chromosomal regions studied for either the whole IBD dataset or the CD subgroup. The multipoint maximum logarithm of odds scores were less than 0.7 for all four regions. Exclusion mapping could significantly exclude chromosomes 3, 7, and 12. Despite earlier findings, we could significantly exclude linkage of CD with previously reported regions on chromosomes 12, 7, and 3, and could not find evidence for linkage to chromosome 16. It is important to report these findings in light of the genetic heterogeneity of IBD. A genome-wide search on a larger group of affected siblings is being analyzed to detect other possible susceptibility loci in the Belgian population.

Participatory environmental health research in Aotearoa/New Zealand: constraints and opportunities

Within the Aotearoa/New Zealand context, this article identifies opportunities for, as well as constraints on, using participatory research to address environmental health concerns. In New Zealand, principles of partnership fundamental to the Treaty of Waitangi, and the requirements for consultation within the Resource Management Act, provide a framework for participatory approaches. Participatory environmental health research integrates knowledge from various scientific and community sources. It also fosters the innovation, evaluation, and sharing of information that new public health approaches demand. As an emerging field in Aotearoa/New Zealand, it must draw on experience from resource management, rural development, and public health research and practice. Water quality is used as an example of the complexity of environmental health issues and of the potential benefits of engaging stakeholders where long-term health and well-being require balancing ecosystem integrity, economic viability, and social processes.

Glucose attenuation of memory impairments

The performance of pigeons in a short-term memory procedure (delayed matching-to-sample) was studied over a range of retention intervals from 0.2 s to 24.0 s. The authors examined the ability of 3 dose levels of glucose (0, 50, and 100 mg/kg) to alleviate memory impairments produced by administration of scopolamine (0.03 mg/kg), by a reduction in the sample-response requirement and by interpolating retroactive interference in the retention interval (houselight illumination). Glucose administration attenuated the deficit produced by scopolamine and by the reduced sample-response requirement, by reversing the decrement in accuracy at 0 delay. Glucose did not, however, reverse the increase in rate of forgetting generated by retroactive interference. The results suggest that the mode of action by which glucose is able to attenuate drug-induced and behavioral impairments in memory may be through an effect on attentional or encoding processes.