Validation of dried blood spot sampling for detecting SARS-CoV-2 antibodies and total immunoglobulins in a large cohort of asymptomatic young adults

BACKGROUND

Detecting antibody responses following infection with SARS-CoV-2 is necessary for sero-epidemiological studies and assessing the role of specific antibodies in disease, but serum or plasma sampling is not always viable due to logistical challenges. Dried blood spot sampling (DBS) is a cheaper, simpler alternative and samples can be self-collected and returned by post, reducing risk for SARS-CoV-2 exposure from direct patient contact. The value of large-scale DBS sampling for the assessment of serological responses to SARS-CoV-2 has not been assessed in depth and provides a model for examining the logistics of using this approach to other infectious diseases. The ability to measure specific antigens is attractive for remote outbreak situations where testing may be limited or for patients who require sampling after remote consultation.

METHODS

We compared the performance of SARS-CoV-2 anti-spike and anti-nucleocapsid antibody detection from DBS samples with matched serum collected by venepuncture in a large population of asymptomatic young adults (N = 1070) living and working in congregate settings (military recruits, N = 625); university students, N = 445). We also compared the effect of self-sampling (ssDBS) with investigator-collected samples (labDBS) on assay performance, and the quantitative measurement of total IgA, IgG and IgM between DBS eluates and serum.

RESULTS

Baseline seropositivity for anti-Spike IgGAM antibody was significantly higher among university students than military recruits. Strong correlations were observed between matched DBS and serum samples in both university students and recruits for the anti-spike IgGAM assay. Minimal differences were found in results by ssDBS and labDBS and serum by Bland Altman and Cohen kappa analyses. LabDBS achieved 82.0% sensitivity and 98.2% specificity and ssDBS samples 86.1% sensitivity and 96.7% specificity for detecting anti-Spike IgGAM antibodies relative to serum samples. For anti-SARS-CoV-2 nucleocapsid IgG there was qualitatively 100% agreement between serum and DBS samples and weak correlation in ratio measurements. Strong correlations were observed between serum and DBS-derived total IgG, IgA, and IgM.

CONCLUSIONS

This is the largest validation of DBS against paired serum for SARS-CoV-2 specific antibody measurement and we have shown that DBS retains performance from prior smaller studies. There were no significant differences regarding DBS collection methods, suggesting that self-collected samples are a viable sampling collection method. These data offer confidence that DBS can be employed more widely as an alternative to classical serology.

A Thermodynamic Model for Interpreting Tryptophan Excitation-Energy-Dependent Fluorescence Spectra Provides Insight Into Protein Conformational Sampling and Stability

It is now over 30 years since Demchenko and Ladokhin first posited the potential of the tryptophan red edge excitation shift (REES) effect to capture information on protein molecular dynamics. While there have been many key efforts in the intervening years, a biophysical thermodynamic model to quantify the relationship between the REES effect and protein flexibility has been lacking. Without such a model the full potential of the REES effect cannot be realized. Here, we present a thermodynamic model of the tryptophan REES effect that captures information on protein conformational flexibility, even with proteins containing multiple tryptophan residues. Our study incorporates exemplars at every scale, from tryptophan in solution, single tryptophan peptides, to multitryptophan proteins, with examples including a structurally disordered peptide, de novo designed enzyme, human regulatory protein, therapeutic monoclonal antibodies in active commercial development, and a mesophilic and hyperthermophilic enzyme. Combined, our model and data suggest a route forward for the experimental measurement of the protein REES effect and point to the potential for integrating biomolecular simulation with experimental data to yield novel insights.

193 Evaluation of the ‘One-Stop Diagnostic Head and Neck Lump Clinic' At A Tertiary Head and Neck Centre

An urgent neck lump service was introduced at the Freeman Hospital (Newcastle-Upon-Tyne) in 2017. All 2-week-wait urgent head and neck referrals were triaged into this service. The clinic involves clinical examination by a head and neck specialist and if appropriate an urgent ultrasound scan (USS) in clinic +/- a fine needle aspiration for cytology (FNAC). This centralised system means patients can be diagnosed earlier and thus receive treatment swiftly.

This audit aimed to primarily identify: The prevalence/pick-up rate of cancer diagnosed through the clinic The utilisation of USS/FNAC The time-to-treatment initiation

Data was collated retrospectively through the electronic record system. The initial evaluation was conducted between June-November 2018 (n = 191). The subsequent re-evaluation was performed between September-November 2019 (n = 159), following increased clinic capacity, implementation of methods to increase awareness and a formal triage process.

In the initial evaluation over 6 months (n = 191), 9.9% underwent an USS in the clinic and 9.95% at a later date. 18% of patients underwent a FNAC. 6.8% patients were diagnosed with cancer. The mean time-to-treatment initiation was 36 days.

In the re-evaluation over 3 months (n = 159), 23.2% had an USS in the clinic and 30.2% at a later date. 13% of patients underwent a FNAC. 9.4% of patients were diagnosed with cancer. The mean time-to-treatment initiation was 44 days.

This affirms the benefits of a swift ‘one-stop clinic’. On average, patients diagnosed with cancer had treatment initiation 40-days post-review. Furthermore, even with a triage process only 1 in 10 patients had cancer.

Rescan Time Delays in Ischemic Stroke Imaging: A Retrospective Observation and Analysis of Causes and Clinical Impact

BACKGROUND AND PURPOSE

Delays to reperfusion negatively impact outcomes of patients with ischemic stroke, yet current guidelines recommend selective sequential imaging for thrombectomy candidates. We aimed to quantify and analyze time delays associated with rescanning in sequential acute stroke imaging.

MATERIALS AND METHODS

This was a retrospective cohort study of consecutive patients with acute ischemic stroke who underwent imaging for treatment decision-making from January 1, 2017, to June 30, 2020. Rescan time delay was defined as ≥10-minute difference between initial NCCT and CTA ± CTP. Mean rescan time delays in comprehensive and primary stroke centers were compared. Bivariate and multivariable regression analyses assessed clinical and imaging factors associated with rescanning time delays and early outcomes.

RESULTS

A total of 588 patients with acute ischemic were included in statistical analyses. Rescanning occurred in 27.9% (164/588 patients), with a mean time delay of 53.7 (SD, 43.4) minutes. For patients presenting at primary compared with comprehensive stroke centers, rescan time delays were more common (59.6% versus 11.8%, P < .001), with longer delays (65.4 [SD, 45.4] minutes versus 23.6 [SD, 14.0] minutes, P < .001). Independent predictors of rescan time delays included primary stroke center presentation, intravenous thrombolysis administration, black race, admission NIHSS ≥10, baseline independent ambulation, and onset-to-comprehensive stroke center arrival in ≥6 hours. Protocols for early simultaneous comprehensive CT (NCCT + CTA + CTP) were associated with lower odds of time delays (OR = 0.34; 95% CI, 0.21-0.55). Rescanning was associated with lower odds of home discharge (OR = 0.53; 95% CI, 0.30-0.95).

CONCLUSIONS

A sequential approach to CT-based imaging may be significantly associated with prolonged acute stroke evaluations. Adoption of early simultaneous comprehensive CT could minimize treatment delays and improve outcomes.

Large diversity in Danish health literacy profiles: perspectives for care of long-term illness and multimorbidity

BACKGROUND

Health literacy is an important, modifiable, social determinant of health. This study aims to explore health literacy challenges of people with long-term illness or multimorbidity and provide detailed profiles revealing health literacy strengths and weaknesses within a Danish population.

METHODS

In this cross-sectional study among Danish individuals (n = 490), health literacy was assessed using the nine-scale Health Literacy Questionnaire (HLQ). Using multiple logistic regression and hierarchical cluster analysis, we estimated the association between HLQ scale scores and the likelihood of long-term illness and multimorbidity, and identified socio-demographic and health characteristics related to profiles of health literacy strengths and weaknesses.

RESULTS

An increase in 'actively managing my health' and 'social support for health' decreased the odds of having a long-term illness [odds ratio, OR 0.53 (0.31-0.9); OR 0.43 (0.24-0.74)] and multimorbidity [OR 0.51 (0.26-0.98); OR 0.33 (0.17-0.62)], respectively. Conversely, an increase in 'healthcare provider support' increased the odds of having long-term illness [OR 2.97 (1.78-5.08)] and multimorbidity [OR 2.94 (1.53-5.87)], respectively. Five profiles were identified based on the cluster analysis. Each cluster was characterized by specific health characteristics, e.g. Cluster A by better health status (χ2 = 39.976 (4), P < 0.001) and well-being (χ2 = 28.832 (4), P < 0.001) and Cluster D by poor health status (χ2 = 39.976 (4), P < 0.001) and increased likelihood of long-term illness (χ2 = 18.641 (4), P < 0.001).

CONCLUSIONS

The association of health literacy with long-term illness and multimorbidity in combination with the health literacy profiling based on cluster analysis provides a comprehensive needs assessment and a promising starting point for the development of health literacy responsive interventions.

How applicable is the TNM 8 staging for human papillomavirus (HPV) related oropharyngeal squamous cell carcinoma (OPSCC) to a UK population of 106 patients? : A cohort comparison of the TNM 7 and TNM8 staging systems for HPV positive oropharyngeal cancer in a UK population

PURPOSE

TNM8 introduced a new staging system for HPV positive oropharyngeal squamous cell carcinoma (OPSCC). This study aimed to investigate whether the changes made in TNM8 offer the perceived benefit in prognostication when compared to TNM7 in a specific patient population in the North East of England.

METHODS

A retrospective cohort comparison study of all patients with HPV positive OPSCC (n = 106) through the Newcastle Head and Neck MDT between January 2012 to December 2014. Overall survival (OS) and Disease specific survival (DSS) data at 3 years was gathered for both TNM7 and TNM8. Log rank test was used to compare survival curves. Harrell's C-index adjusted for age and smoking status was used to assess prognostic ability of the two staging methods.

RESULTS

TNM8 downstages disease (TNM7 stage IV patients n = 74, TNM8 stage IV patients n = 2) but gives a more even distribution of patients across disease stages. Survival for TNM8 stage II and III is similar. In our small cohort, the log-rank test detected differences in OS between stages for both scoring methods (TNM7 p = 0.006, TNM8 p < 0.001) and similarly for DSS (TNM7 p = 0.001, TNM8 p < 0.001). Harrell's C-index was similar for both models for OS (TNM7 0.71, TNM8 0.71) and DSS (TNM7 0.74, TNM8 0.70).

CONCLUSION

TNM8 downstages disease and prognosticates well for stage I disease but does not differentiate between stage II and III disease when compared to TNM7. Further adaptation is required to address this to make TNM8 a more accurate prognostic tool.

A nationwide parent survey of antibiotic use in Australian children

BACKGROUND

Antimicrobial resistance is increasing globally, largely due to high rates of antibiotic use and misuse. Factors that influence frequent antibiotic use in children are poorly understood.

OBJECTIVES

This study describes rates of antibiotic use in Australian children and investigates parental factors including knowledge, attitudes and behaviours that influence antibiotic use.

METHODS

An online questionnaire relating to antibiotic use was administered as part of the Royal Children's Hospital National Child Health Poll to a randomly recruited nationwide sample of parents or guardians of children aged 0-17 years in Australia. Data on antibiotic use in children and parental knowledge of appropriate indications for antibiotics and behaviours were collected. Standard binary logistic regression was used to assess associations between parent demographics and behaviour with antibiotic administration.

RESULTS

The survey was completed by 2157 parents (64% completion rate), of which 1131 (52%) reported having given oral antibiotics to one or more of their children in the preceding 12 months. Of the 3971 children represented overall, 1719 (43%) had received at least one course of antibiotics. The average number of courses per child was 0.86 overall and 1.96 courses per child among those with reported antibiotic use. Notably, 194/1131 (17%) parents reported giving antibiotics to their child without a prescription. Poor parental knowledge of antibiotic indications was associated with antibiotic use.

CONCLUSIONS

Reducing excessive use of antibiotics in children is necessary in the global strategy for preventing antimicrobial resistance. This study identified areas for public health interventions to educate parents and increase regulation of access to antibiotics.

C-13 Sex Differences in Cognitive and Neurobiological Markers of Alzheimer's Disease

Objective

Previous work has demonstrated that intra-individual cognitive variability (IICV) has predictive power similar to traditional Alzheimer’s disease (AD) biomarkers, such as CSF or hippocampal volume (HV) loss. Genetic factors, such as sex, have been identified as predictors of cognitive decline. Analysis of sex differences in IICV and other biomarkers may elucidate additional dimensions of this metric.

Method

Baseline neurocognitive test and neuroimaging data from 335 participants with ≥2 visits enrolled in the Wisconsin Alzheimer’s Disease Research Center Clinical Core were included. Z-scores were calculated comparing individual performance to group performance by test (Rey Auditory Verbal Learning Test (Learning and Delayed Recall), Trail Making Test (A and B), and either Boston Naming Test (BNT) or Multilingual Naming Test (MINT)). MINT scores were converted to BNT scores using the NACC Crosswalk Study. The standard deviation of z-scores across tests was calculated to determine IICV. Characteristics by sex were compared using Mann-Whitney and Fisher’s Exact tests. Spearman’s Rho was calculated to compare IICV and HV (relative to intercranial volume).

Results

At baseline (Table 1): (1) Males had more education than females; (2) females had both higher relative HV and IICV; and (3) in females, relative HV demonstrated a weak positive correlation with baseline IICV (Figure 1).

Conclusions

IICV has previously demonstrated potential as a cost-effective non-invasive marker of preclinical AD. In females, larger relative HV and its correlation with IICV may be due to differences in metabolic brain age or concurrent progression of HV and IICV through the AD process. Analyses of other biopsychosocial factors are needed.

C-12 Race and Sex Differences in Cognitive and Neurobiological Markers of Alzheimer's Disease

Objective

Intra-Individual Cognitive Variability (IICV) previously demonstrated predictive power similar to AD biomarkers (i.e., CSF and hippocampal volume (HV) loss). Previous work suggested sex differences in relative HV and IICV. Additionally, IICV differs in whites and underrepresented racial groups (URG). Our objective was to analyze these sex differences in white and URG participants.

Method

Baseline neurocognitive test and neuroimaging data from 335 cognitively healthy participants with ≥2 visits enrolled in the Wisconsin ADRC Clinical Core were included. Z-scores were calculated comparing individual performance to group performance by test (Rey Auditory Verbal Learning Test (Learning and Delayed Recall), Trail Making Test (A and B), and either Boston Naming Test (BNT) or Multilingual Naming Test (MINT)). MINT scores were converted to BNT scores using the NACC Crosswalk Study. The standard deviation of z-scores across tests was calculated to determine IICV. Characteristics by race and sex were compared using Mann-Whitney, Fisher’s Exact, and Kruskal-Wallis tests. Spearman’s Rho was calculated to compare baseline IICV and relative HV.

Results

At baseline (Table 1), differences across racial groups in age, years of education, relative HV, and IICV were identified. Sex and racial group differences were identified (Table 2). A weak positive correlation between HV and IICV was seen in white females (Figure 1).

Conclusions

IICV has potential to become a cost-effective, non-invasive marker of preclinical AD. Again, correlation between HV and IICV was seen, but only in white females. Analyses suggest group differences between white and URG males and females. However, more data is needed to further explore these differences.

Does the gene matter? Genotype-phenotype and genotype-outcome associations in congenital melanocytic naevi

Background

Genotype–phenotype studies can identify subgroups of patients with specific clinical features or differing outcomes, which can help shape management.

Objectives

To characterize the frequency of different causative genotypes in congenital melanocytic naevi (CMN), and to investigate genotype–phenotype and genotype–outcome associations.

Methods

We conducted a large cohort study in which we undertook MC1R genotyping from blood, and high‐sensitivity genotyping of NRAS and BRAF hotspots in 156 naevus biopsies from 134 patients with CMN [male 40%; multiple CMN 76%; projected adult size (PAS) > 20 cm, 59%].

Results

Mosaic NRAS mutations were detected in 68%, mutually exclusive with BRAF mutations in 7%, with double wild‐type in 25%. Two separate naevi were sequenced in five of seven patients with BRAF mutations, confirming clonality. Five of seven patients with BRAF mutations had a dramatic multinodular phenotype, with characteristic histology distinct from classical proliferative nodules. NRAS mutation was the commonest in all sizes of CMN, but was particularly common in naevi with PAS > 60 cm, implying more tolerance to that mutation early in embryogenesis. Facial features were less common in double wild‐type patients. Importantly, the incidence of congenital neurological disease, and apparently of melanoma, was not altered by genotype; no cases of melanoma were seen in BRAF‐mutant multiple CMN, however, this genotype is rare.

Conclusions

CMN of all sizes are most commonly caused by mutations in NRAS. BRAF is confirmed as a much rarer cause of multiple CMN, and appears to be commonly associated with a multinodular phenotype. Genotype in this cohort was not associated with differences in incidence of neurological disease in childhood. However, genotyping should be undertaken in suspected melanoma, for guidance of treatment.

What's already known about this topic?

Multiple congenital melanocytic naevi (CMN) have been shown to be caused by NRAS mosaic mutations in 70–80% of cases, by BRAF mosaicism in one case report and by inference in some previous cases.

There has been debate about genotypic association with different sizes of CMN, and no data on genotype–outcome.

What does this study add?

NRAS mosaicism was found in 68%, BRAF in 7% and double wild‐type in 25% of cases of CMN.

NRAS was the commonest mutation in all sizes of CMN, but was nearly universal in projected adult size > 60 cm.

BRAF is often associated with a distinct multinodular clinical/histological phenotype.

Adverse outcomes did not differ between genotypes on current numbers.

https://doi.org/10.1111/bjd.18747 available online

Long-term outcomes from prophylactic or episodic treatment of haemophilia A: A systematic review

INTRODUCTION

Evaluating treatment success in patients with haemophilia A (HA) remains a vigorous debate, especially concerning the interpretation of results from clinical and observational research. The benefits of short-term prophylaxis are well established, but long-term outcomes, particularly related to humanistic and economic burden, are not as well understood.

AIM

We conducted a systematic literature review to evaluate the association of episodic or prophylactic bleed control with long-term clinical, humanistic and economic outcomes.

METHODS

Studies published in English between 1 January 2006 and 15 December 2016 were included. Participants had HA (with or without inhibitors), received prophylactic or episodic treatment and had at least 4 years of treatment or follow-up. Results were analysed qualitatively with descriptive findings.

RESULTS

A total of 2091 records were screened, resulting in 19 studies from 20 publications for inclusion. Most studies included children (84%), were limited to patients with severe disease (74%) and were conducted in Europe or North America (89%). Ten studies (53%) included patients with inhibitors. Median study follow-up ranged from 5 to 19 years. Long-term bleeding and haemarthrosis outcomes were consistently better for patients receiving prophylaxis, who also required fewer hospitalizations or surgeries. Health-related quality of life, functionality and productivity were generally more favourable in patients receiving prophylaxis. Quantitative comparisons were not feasible due to the lack of consistency in endpoint collection and reporting among studies.

CONCLUSION

This systematic review confirmed that the benefits of prophylactic treatment on short-term outcomes translate to broader long-term clinical, humanistic and economic benefits. Better harmonization of data collection and outcome assessments across both registries and clinical studies is needed to allow for effective comparisons across studies and across data sources.

Conceptualisation and development of the Conversational Health Literacy Assessment Tool (CHAT)

Background

The aim of this study was to develop a tool to support health workers’ ability to identify patients’ multidimensional health literacy strengths and challenges. The tool was intended to be suitable for administration in healthcare settings where health workers must identify health literacy priorities as the basis for person-centred care.

Methods

Development was based on a qualitative co-design process that used the Health Literacy Questionnaire (HLQ) as a framework to generate questions. Health workers were recruited to participate in an online consultation, a workshop, and two rounds of pilot testing.

Results

Participating health workers identified and refined ten questions that target five areas of assessment: supportive professional relationships, supportive personal relationships, health information access and comprehension, current health behaviours, and health promotion barriers and support.

Conclusions

Preliminary evidence suggests that application of the Conversational Health Literacy Assessment Tool (CHAT) can support health workers to better understand the health literacy challenges and supportive resources of their patients. As an integrated clinical process, the CHAT can supplement existing intake and assessment procedures across healthcare settings to give insight into patients’ circumstances so that decisions about care can be tailored to be more appropriate and effective.

National study of parental confidence in general practitioners

AIM

To assess a national sample of Australian parental confidence in general practitioner (GP) care for illness and injury for their children.

METHODS

Cross-sectional, internet-based survey of a national, representative sample of parents of children birth - 17 years in Australia was used. Purposeful recruitment was used to achieve a national, representative sample of 2100 Australian parents, reflective of demographic and geographic distribution based on census data. Parents were asked to indicate their degree of confidence in a GP to handle medical problems as well as their preference for, and use of, paediatric speciality care for their children.

RESULTS

Fewer than half of parents (44%) reported that they were completely confident in a GP to provide general care as defined as 'can handle almost all general health issues for my child'. A slightly greater proportion of parents (56%) were completely confident in a GP to provide care for minor injuries, defined as injuries not requiring an X-ray. Greater confidence in general care was seen among parents >40 years of age and those whose GP is always bulk billed.

CONCLUSIONS

Parental confidence in GPs is an important issue. Our findings that fewer than half of parents are completely confident in their GP to provide general care to their child may be an influencing factor on current health-care utilisation trends. The potential implications of low parental confidence in GPs are greater numbers of emergency department presentations for children with lower urgency conditions and increased referrals of children for specialty care.

General illness and psychological factors in patients with chronic nasal symptoms

OBJECTIVES

Only a minority of patients referred to specialists with sinonasal symptoms have clear evidence of chronic rhinosinusitis (CRS). This study aims to estimate the prevalence of and associations between (i) general illness factors (fatigue, autonomic dysfunction) and (ii) psychological factors (anxiety, depression, somatisation, personality traits) in patients presenting with sinonasal symptoms.

DESIGN

The following validated questionnaires were administered to patients: the Sino-Nasal Outcome Test-22 (SNOT-22) identifying symptom burden, Composite Autonomic Symptom Score-31 (COMPASS-31) measuring autonomic function, Chalder Fatigue Questionnaire, Patient Health Questionnaire-15 (PHQ-15) addressing somatisation symptoms, Hospital Anxiety and Depression Scale (HADS), and the International Personality Item Pool-50 (IPIP-50). Comparisons were made with normative and general population data, and relationships were analysed using nonparametric correlation.

SETTING

Secondary care ENT outpatients.

PARTICIPANTS

Adults referred with chronic sinonasal symptoms.

MAIN OUTCOME MEASURES

SNOT-22, COMPASS-31, Chalder, PHQ-15, HADS, and IPIP-50 questionnaire scores.

RESULTS

Sixty-one patients were included. There was a high prevalence of all general and psychological factors assessed compared with controls. Total SNOT-22 scores showed significant correlation with Chalder fatigue scores, total autonomic dysfunction score, anxiety, depression, somatisation tendencies and the emotionally unstable personality trait. Emotional instability and psychological dysfunction correlated significantly with sleep and psychological subscales of SNOT-22 but not the rhinological or ear/facial subscales.

CONCLUSION

Patients with sinonasal symptoms demonstrate high prevalence and complex associations of general illness factors, psychological distress and certain personality traits. The SNOT-22 is a valuable tool, but its utility is limited by correlations with these confounding factors (eg psychological factors) that may exaggerate the total score. The use of the SNOT-22 component subscales is likely to provide more clinically meaningful and discriminant information.

Trans-oral robotic assisted tongue base mucosectomy for investigation of cancer of unknown primary in the head and neck region. The UK experience

OBJECTIVES

The diagnosis of cancer of unknown primary (CUP) in head and neck occurs when the treating clinicians have utilised all available diagnostic tests and failed to identify the origin of the disease. There is no agreed consensus on which diagnostic investigations to use, or the order in which to use them in, although broad recommendations exist. Small tumours arising in the tongue base can be below the limits of resolution of conventional diagnostic techniques. Given the difficulty in targeting the tongue base, current practice involves blind random biopsies, which leads to a variable detection rate. Robotically assisted surgical removal of the tongue base, tongue base mucosectomy (TBM) has been shown to improve diagnostic yield. This study reports the diagnostic hit rate for tongue base primaries using this technique.

DESIGN

Retrospective case review.

SETTING

UK Head and Neck Centres.

PARTICIPANTS

Patients presenting as an unknown primary, investigated with clinical examination, PET-CT and palatine tonsillectomy.

MAIN OUTCOME MEASURES

The detection of a primary site of head and neck cancer in the otherwise unknown primary tumour.

RESULTS

The primary tumour site was identified in the tongue base in 53% (n=17) of patients. In 15 patients the tumour was in the ipsliateral tongue base (88%) while in two cases (12%) the tumour was located in contra lateral tongue base.

CONCLUSIONS

Trans-oral robotic assisted TBM raises the possibility of identifying over 50% of tumours that would otherwise be classified as CUP. Identifying these in the contralateral tongue base has implications for treatment planning and outcome.

The effect of high altitude on central blood pressure and arterial stiffness

Central arterial systolic blood pressure (SBP) and arterial stiffness are known to be better predictors of adverse cardiovascular outcomes than brachial SBP. The effect of progressive high altitude (HA) on these parameters has not been examined. Ninety healthy adults were included. Central BP and the augmentation index (AI) were measured at the level of the brachial artery (Uscom BP⁺ device) at <200 m and at 3619, 4600 and 5140 m. The average age of the subjects (70% men) were 32.2±8.7 years. Compared with central arterial pressures, brachial SBP (+8.1±6.4 mm Hg; P<0.0001) and pulse pressure (+10.9±6.6 mm Hg; P<0.0001) were significantly higher and brachial diastolic BP was lower (-2.8±1.6 mm Hg; P<0.0001). Compared with <200 m, HA led to a significant increase in brachial and central SBP. Central SBP correlated with AI (r=0.50; 95% confidence interval (CI): 0.41-0.58; P<0.0001) and age (r=0.32; 95% CI: 21-0.41; P<0.001). AI positively correlated with age (r=0.39; P<0.001) and inversely with subject height (r=-0.22; P<0.0001), weight (r=-0.19; P=0.006) and heart rate (r=-0.49; P<0.0001). There was no relationship between acute mountain sickness scores (Lake Louis Scoring System (LLS)) and AI or central BP. The independent predictors of central SBP were male sex (coefficient, t=4.7; P<0.0001), age (t=3.6; P=0.004) and AI (t=7.5; P<0.0001; overall r²=0.40; P<0.0001). Subject height (t=2.4; P=0.02), age (7.4; P<0.0001) and heart rate (t=11.4; P<0.0001) were the only independent predictors of AI (overall r²=0.43; P<0.0001). Central BP and AI significantly increase at HA. This rise was influenced by subject-related factors and heart rate but not independently by altitude, LLS or SpO₂.

One-year swallowing outcomes following transoral laser microsurgery +/- adjuvant therapy versus primary chemoradiotherapy for advanced stage oropharyngeal squamous cell carcinoma

OBJECTIVES

To assess the between-group change in swallowing function from baseline to 12 months following treatment, for patients treated for resectable stage III and IVA oropharyngeal squamous cell carcinoma. To assess the within-group change in swallowing function between 3 and 12 months following treatment.

DESIGN

Non-randomised cohort study.

SETTING

A single head and neck cancer unit with oncology services held at the nearby regional treatment centre.

PARTICIPANTS

Twenty-five patients treated with Transoral Laser Microsurgery +/- adjuvant (chemo)radiotherapy (Transoral Laser Microsurgery) observed alongside an historic cohort of 33 patients treated with (chemo)radiotherapy.

MAIN OUTCOME MEASURES

The patient reported MD Anderson Dysphagia Inventory (MDADI), an objective timed Water Swallow Test, and the clinician rated normalcy of diet subsection of the Performance of Swallowing Scale .

RESULTS

Between baseline and 12 months, patients treated with primary (chemo)radiotherapy demonstrated greater deterioration in swallowing function compared to Transoral Laser Microsurgery for all 3 swallowing measures. Between 3 and 12 months, the only significant change was an improvement in Performance of Swallowing Scale scores in the (chemo)radiotherapy group.

CONCLUSIONS

This is the first study to report the results of a complimentary set of swallowing measures for patients treated with Transoral Laser Microsurgery, observed alongside a cohort of (chemo)radiotherapy patients. The preliminary results suggest a benefit in swallowing function for Transoral Laser Microsurgery over (chemo)radiotherapy during the year following treatment.

Brain natriuretic peptide and NT-proBNP levels reflect pulmonary artery systolic pressure in trekkers at high altitude

Our objective was to evaluate the utility of the natriuretic peptides BNP (brain natriuretic peptide) and NT-proBNP as markers of pulmonary artery systolic pressure (PASP) in trekkers ascending to high altitude (HA). 20 participants had BNP and NT-proBNP assayed and simultaneous echocardiographic assessment of PASP performed during a trek to 5150 m. PASP increased significantly (p=0.006) with ascent from 24+/-4 to 39+/-11 mm Hg at 5150 m. At 5150 m those with a PASP>/=40 mm Hg (n=8) (versus those with PASP<40 mm Hg) had higher post-exercise BNP (pg/ml): 54.5+/-36 vs. 13.4+/-17 (p=0.012). Their resting BNP at 5150 m was also higher: 57.3+/-43.4 vs. 12.6+/-13 (p=0.017). In those with a pathological (>/=400 pg/ml) rise in NT-proBNP at 5150 m (n=4) PASP was significantly higher: 45.9+/-7.5 vs. 32.2+/-6.2 mm Hg (p=0.015). BNP and NT-proBNP may reflect elevated PASP, a central feature of high altitude pulmonary oedema, at HA.

Abstract P6-04-21: AIB1 expression specifically predicts breast cancer patient response to aromatase inhibitor therapy

Aromatase inhibitors (AI) have evolved over the last decade into an effective therapeutic regime for postmenopausal women with primary or advanced breast cancer. Despite their remarkable success in the clinic, intrinsic resistance to therapy occurs in a proportion of patients, while other patients who respond initially to treatment will relapse with recurrent disease. Previous studies suggest that this may be due, at least in part to estrogen receptor (ER) hypersensitivity.

We undertook ER ChIPseq analysis on AI resistant cell model and data for this suggests that ER transcriptional regulation alone may not be responsible for the development of the resistant phenotype. We examined the role of the established ER coactivator protein AIB1. AIB1 has previously been associated with initiation of breast cancer and resistance to endocrine therapy. In tamoxifen treated patients, expression of AIB1 in conjunction with an activated HER2 cascade has been associated with treatment resistance and early disease recurrence. By contrast, we have observed that AIB1 alone can predict response to AIs. In our TMA the expression of AIB1 associated with disease recurrence (p = 0.025) and reduced disease free survival time (p = 0.0471) in patients treated with AIs as first-line therapy. Reflecting increased growth factor activity reported in AI resistance, AIB1 expression associated with the growth factor second messenger signaling proteins, p-Src and pERK1/2, but not the receptor HER2. These results suggest that AIB1 may utilize additional transcription factors other than ER to drive endocrine resistance. Additionally, we show that AIB1 is highly expressed in AI resistant metastases; therefore, monitoring AIB1 expression may be useful to screen for disease progression and detect disease advancement before metastases appear.

Our studies of cell line models of AI resistance suggest that AIB1 may play a functional role in aggressive, migratory, phenotype of AI resistance. We have generated cell line models of resistance to letrozole (LetR) and anastrozole (AnaR). Our resistance models have higher levels of AIB1 and have increased migratory capacity. Interestingly, knockdown of AIB1 reduces the migratory capacity of the resistant cells.

Furthermore, we have observed that AIB1 regulation of ER target genes is selectively enhanced in AI resistant cells in a promoter specific context. AIB1 recruitment to ER target genes such as pS2 and Myc becomes insensitive to letrozole. By contrast, AIB1 recruitment to cyclinD1 retained letrozole sensitivity. Our evidence suggests that steroidal regulation of transcription factors such as Jun and Fos may contribute to this promoter-specific regulation of ER target genes.

We establish a role for AIB1 in AI-resistant breast cancer and describe a new mechanism of ERalpha/AIB1 gene regulation which could contribute to the development of an aggressive tumour phenotype. We provide evidence of a central role for AIB1 in regulating selective ER transcriptional activity and driving tumour recurrence in AI treated patients. Tackling the emerging problem of AI resistance in a timely fashion will enable us to tailor existing therapies and improve outcome in specific patient groups before disease recurrence becomes a clinical issue.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-04-21.

Abstract P1-05-06: A novel mutation in the tyrosine kinase domain of ErbB2: molecular and proteomic investigation of its role in breast cancer invasion

Introduction: A landmark genomic study revealed 17 somatic coding mutations in a lobular metastatic breast tumor, none of which were present in the patient's primary tumor. Among these was a novel mutation in the tyrosine kinase domain of ErbB2, a gene often amplified in breast cancer. Other mutations in this domain have been shown to stimulate transformation, growth and invasion in breast cancer cells. We hypothesize that an accumulation of mutations in the primary tumor over time preceded the development of an invasive clone, which allowed it to metastasise. Therefore, we investigated the specific effects of ErbB2 on cellular signalling and invasion, in conjunction with proteomic analyses to show its effects on global protein expression.

Methods: Wild-type and mutant ErbB2 cDNAs were cloned into V180 pLP 3X FLAG-tagged expression vectors. T47D breast cancer cells were transfected with one of these constructs. Protein was detected by immunoblotting with an anti-ErbB2 antibody. Membranes were then immunoblotted with an anti-phospho-ERK1/2 antibody. Transfected cells were seeded onto Matrigel; cells that migrated through the matrix were stained and counted after 48h.

To identify global proteomic changes caused by mutant ErbB2, T47D cells transfected with mutant/wild-type ErbB2 or vector control, were differentially labeled by growing them in medium containing various lysine/arginine isotopes (known as stable isotope labeling of amino acids in cell culture; SILAC). Protein lysates were mixed and subjected to LC-MS/MS mass spectrometry. Proteomic changes were analysed using MaxQuant and DAVID software.

Results: Overexpression of the wild-type or mutant ErbB2 genes produced protein expression in T47D, a non-invasive breast cancer cell line, confirmed by western blotting. To measure signalling downstream of ErbB2, we measured levels of the MAP kinase phospho-ERK1/2. Increased phosphorylation of ERK1/2 was demonstrated in cells expressing mutated ErbB2, compared with cells transfected with wild-type. This indicates increased activation of mutant ErbB2, demonstrating distinct phenotypic effects between wild-type and mutant ErbB2 in breast cancer cells. To analyze whether increased activation was accompanied by enhanced invasive properties, invasion assays were performed using Matrigel. A greater number of cells (1.5-fold increase) expressing mutant ErbB2 migrated across this matrix compared with wild-type-expressing cells.

Global proteomic analysis of T47D cells overexpressing wild-type or mutant ErbB2 yielded 1,357 total proteins, of which 543 could be quantified. Two subsets of proteins were identified, whose levels were either increased or decreased, in the mutant versus wild-type-transfected lysates (compared to control ratios). Proteins elevated in the mutant-expressing cells included candidates involved in cell migration, inhibition of apoptosis and promotion of cellular survival. Proteins showing reduced expression were involved in pathways including adhesion and DNA damage response.

Conclusion: This previously undescribed mutation in the tyrosine kinase domain of ErbB2 differentially effects downstream signalling pathways and may play a role in invasion of breast cancer cells.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-05-06.

The prevalence, influential factors and mechanisms of relative age effects in UK Rugby League

Relative age effects (RAEs), reflecting observed inequalities in participation and attainment as a result of annual age-grouping policies in youth sport, are common in most team sports. The aims of this study were to determine if and when RAEs become apparent in Rugby League, determine how influential variables (e.g., gender) lead and clarify whether player retention at junior representative levels can explain persistent RAEs. Player data were collected for the male and female community games ranging from Under 7s to Senior (N=15,060) levels, junior representative selections (i.e., Regional) and professional players (N=298). Chi-square analyses found significant (P<0.05) uneven birth date distributions beginning at the earliest stages of the game and throughout into senior professionals. In junior representative selections, 47.0% of Regional and 55.7% of National representative players were born in Quartile 1, with RAE risk increasing with performance level. Gender and nationality were also found to moderate RAE risk. When tracking representative juniors, over 50% were retained for similar competition the following season. Findings clearly demonstrate that RAEs exist throughout Rugby League with early selection, performance level and retention processes, appearing to be key contributing factors responsible for RAE persistence.

Laser bladder perforation from photoselective vaporization of prostate resulting in rhabdomyolysis induced acute renal failure

Hyponatremia and its related comorbidities remain a concern after traditional transurethral resection of the prostrate (TURP). Photoselective vaporization of the prostate (PVP) laser coagulation therapy is a new, relatively bloodless procedure for treatment of benign prostatic hyperplasia (BPH). Perceived benefits with PVP laser TURP include excellent visualization of the operative field during urethral prostatic tissue vaporization and the reduced incidence of laser penetration through the prostatic capsular fibers once the capsule is reached. Theoretically, this would provide a low risk method of perforation during laser TURP. After literature review, we report this as the first case of laser bladder perforation as a complication arising from PVP therapy. This case report discusses the management of acute hyponatremic induced rhabdomyolysis with acute renal failure (ARF) and the recommendation to use sodium chloride vs. sterile water for bladder irrigation during PVP TURP procedures.

The significance of MRI findings for non-rhinological disease

OBJECTIVES

Mucosal changes in the paranasal sinuses are detected in 30-50% of scans for non-rhinological disease. This study assesses the relationship between symptoms of rhinosinusitis and radiological evidence of sinus pathology in patients undergoing magnetic resonance imaging (MRI) scans for unrelated pathology.

DESIGN

Prospective observational study, evaluating symptoms of rhinosinusitis in patients undergoing MRI scanning of the internal acoustic meati. A visual analogue scale (VAS) of rhinological symptoms was completed immediately before scanning, specifying symptoms present at the time of completing the questionnaire. Symptom scores were recorded by one of the investigators, blinded to the MRI images. Two investigators independently rated sinus mucosal thickening for each scan, both of whom were blinded to the symptom scores. Lund and Mackay scoring systems were used for both symptom and radiological scores, which were then compared.

SETTING

Otolaryngology and Radiology Departments in a large teaching hospital.

PARTICIPANTS

Fifty consecutive patients were recruited over a 2-month period.

MAIN OUTCOME MEASURES

Visual analogue scale symptom scores were compared with radiological scores for sinus mucosal thickening.

RESULTS

No statistically significant relationship was demonstrated between rhinological symptoms and radiological features suggestive of rhinosinusitis in patients undergoing MRI scanning for non-rhinological disease.

CONCLUSIONS

The relationship between rhinological symptoms and MRI findings of sinus pathology is not straightforward. Management decisions should be made on the basis of nasal history and endoscopy, rather than radiological findings. This is the first study assessing this relationship by documenting symptoms on the day of scanning, using a validated scoring system.

"Post-nasal drip syndrome": most patients with purulent nasal secretions do not complain of chronic cough

INTRODUCTION

Post-nasal drip syndrome (PNDS) is quoted as a common cause of chronic cough. However, there is little evidence to explain the mechanism by which PNDS may stimulate the cough reflex. This cohort study looks at patients with purulent nasal secretions, who may best represent any potential candidate for PNDS, and observes the frequency of symptomatic coughing.

METHODS

One-hundred and eight consecutive patients referred to a rhinology clinic with symptoms of chronic infective rhinosinusitis, all with purulent nasal secretions identified on nasendoscopy, were observed through investigation and treatment. Patients were initially treated with broad-spectrum antibiotics and nasal douching. The frequency of coughing was recorded pre- and post- treatment.

RESULTS

Eighty-nine percent of patients complained of post-nasal secretions. Twenty-three (21%) patients complained of cough. Eight had co-existing asthma, 3 had bronchiectasis, 1 had sarcoid and 2 had had a recent respiratory tract infection. Therefore 9 patients (8%) had purulent nasal secretions and a cough with no other discernable pathology. Cough improved in 8 of the 9 patients following treatment. Cough improved in 9 of the 14 patients with other possible co-existing causes for cough.

CONCLUSIONS

Only a small proportion of patients with purulent rhinosinusitis without coexisting chest disease complain of cough. Although nasal disease may be a genuine cause for chronic cough it is unlikely to be as common a cause as has been reported. Postnasal secretions do not appear to be an adequate cause for cough and the term 'PNDS' should be replaced by rhinosinusitis when nasal disease is the cause of chronic cough.

The aetiology of chronic cough: a review of current theories for the otorhinolaryngologist

Most studies agree that post-nasal drip syndrome (PNDS), asthma, gastroesophageal reflux disease (GORD), and laryngopharyngeal reflux (LPR) are the commonest causes of chronic cough in the immunocompetent, non-smoking patient who is not taking an angiotensin-converting enzyme inhibitor. No diagnostic test has been found to define those who are said to have PNDS other than a response to a first-generation antihistamine. Examining the available evidence suggests that mechanical stimulation of the pharynx by mucus is not an adequate theory for the production of cough. Inflammatory mediators in the lower airways are raised in PNDS, cough variant asthma and GORD, and the theory that an inflammatory process is affecting 'one airway' is a plausible one. Nasal disease is more likely to result in cough from the co-existing involvement of the lower airways through an as yet undefined pathway, and eosinophil and mast cell mediation appear a likely mechanism.