Development and Validation of the Anaphylaxis Quality of Life Scale for Adults

BACKGROUND

Anaphylaxis is a severe and potentially life-threatening allergic reaction that can have a detrimental impact on quality of life (QoL). There are no validated scales to measure the impact of anaphylaxis on QoL of adults.

OBJECTIVE

The aim of this study was to develop and assess the reliability and validity of a QoL scale for adults with anaphylaxis (Anaphylaxis Quality of Life Scale for Adults [A-QoL-Adults]).

METHODS

All participants were recruited from a specialist allergy clinic and had a confirmed diagnosis of anaphylaxis (as per the World Allergy Organization diagnostic criteria) to food, drugs, venom, or latex or had spontaneous anaphylaxis. Interviews were conducted with 13 adults; data were analyzed using thematic analysis to extract items for a QoL scale. A prototype QoL scale was then completed by 115 participants alongside validated scales to measure generic QoL (World Health Organization Quality of Life Scale [Brief Version] [WHOQoL BREF]), anxiety and depression (Hospital Anxiety and Depression Scale [HADS]), and stress (Perceived Stress Scale [PSS]).

RESULTS

The A-QoL-Adults scale has 21 items demonstrating excellent internal reliability (Cronbach α = 0.96). Factor analysis produced 3 subscales: Emotional Impact; Social Impact; and Limitations on Life. Each has excellent internal reliability (0.92, 0.92, and 0.91, respectively). Poorer anaphylaxis-related QoL (total A-QoL-Adults score and subscale scores) correlated significantly with poorer general QoL and greater anxiety, depression, and stress (all P < .01 with medium-to-large effect sizes).

CONCLUSIONS

The A-QoL-Adults scale is a reliable measure of QoL in adults with anaphylaxis and shows good construct validity. It will offer health care professionals a means to further understand the impact of anaphylaxis on adult patients and could help direct and monitor allergy management and the need for further psychological intervention.

Burden of allergic disease among ethnic minority groups in high-income countries

The COVID‐19 pandemic raised acute awareness regarding inequities and inequalities and poor clinical outcomes amongst ethnic minority groups. Studies carried out in North America, the UK and Australia have shown a relatively high burden of asthma and allergies amongst ethnic minority groups. The precise reasons underpinning the high disease burden are not well understood, but it is likely that this involves complex gene–environment interaction, behavioural and cultural elements. Poor clinical outcomes have been related to multiple factors including access to health care, engagement with healthcare professionals and concordance with advice which are affected by deprivation, literacy, cultural norms and health beliefs. It is unclear at present if allergic conditions are intrinsically more severe amongst patients from ethnic minority groups. Most evidence shaping our understanding of disease pathogenesis and clinical management is biased towards data generated from white population resident in high‐income countries. In conjunction with standards of care, it is prudent that a multi‐pronged approach towards provision of composite, culturally tailored, supportive interventions targeting demographic variables at the individual level is needed, but this requires further research and validation. In this narrative review, we provide an overview of epidemiology, sensitization patterns, poor clinical outcomes and possible factors underpinning these observations and highlight priority areas for research.

'Practical management of suspected hypersensitivity reactions to anti-tuberculosis drugs.'

Tuberculosis (TB) is the commonest cause of death by a single infectious agent globally and ranks amongst the top ten causes of global mortality. The incidence of TB is highest in Low-Middle Income countries (LMICs). Prompt institution of, and compliance with, therapy are cornerstones for a favourable outcome in TB and to mitigate the risk of multiple drug resistant (MDR)-TB, which is challenging to treat. There is some evidence that adverse drug reactions (ADRs) and hypersensitivity reactions (HSRs) to anti-TB drugs occur in over 60% and 3-4% of patients respectively. Both ADRs and HSRs represent significant barriers to treatment adherence and are recognised risk factors for MDR-TB. HSRs to anti-TB drugs are usually cutaneous and benign, occur within few weeks after commencement of therapy and are likely to be T-cell mediated. Severe and systemic T-cell mediated HSRs and IgE mediated anaphylaxis to anti-TB drugs are relatively rare, but important to recognise and treat promptly. T-cell mediated HSRs are more frequent amongst patients with co-existing HIV infection. Some patients develop multiple sensitisation to anti-TB drugs. Whilst skin tests, patch tests and in vitro diagnostics have been used in the investigation of HSRs to anti-TB drugs, their predictive value is not established, they are onerous, require specialist input of an allergist and are resource-dependent. This is compounded by the global, unmet demand for allergy specialists, particularly in low income countries (LICs) / LMICs and now the challenging circumstances of the SARS-CoV-2 pandemic. This narrative review provides a critical analysis of the limited published evidence on this topic and proposes a cautious and pragmatic approach to optimise and standardise the management of HSRs to anti-TB drugs. This includes clinical risk stratification and a dual strategy involving sequential re-challenge and rapid drug desensitisation. Furthermore, a concerted international effort is needed to generate real-time data on ADRs, HSRs, safety and clinical outcomes of these interventions.

Peptide allergen-specific immunotherapy for allergic airway diseases-State of the art

Allergen-specific immunotherapy (AIT) is the only means of altering the natural immunological course of allergic diseases and achieving long-term remission. Pharmacological measures are able to suppress the immune response and/or ameliorate the symptoms but there is a risk of relapse soon after these measures are withdrawn. Current AIT approaches depend on the administration of intact allergens, often comprising crude extracts of the allergen. We propose that the challenges arising from current approaches, including the risk of serious side-effects, burdensome duration of treatment, poor compliance and high cost, are overcome by application of peptides based on CD4⁺ T cell epitopes rather than whole allergens. Here we describe evolving approaches, summarize clinical trials involving peptide AIT in allergic rhinitis and asthma, discuss the putative mechanisms involved in their action, address gaps in evidence and propose future directions for research and clinical development.

The role of a clinical pharmacist in spurious Penicillin allergy: a narrative review

Background A label of penicillin allergy is held by 6-10% of the general population and 15-20% of inpatients. > 90% of these labels are found to be spurious after formal allergy assessment. Carrying an unnecessary label of penicillin allergy is not benign. Such patients may receive second line, more expensive antibiotics, representing a significant impediment to antimicrobial stewardship. Aim of the review To (a) Explain the burden of spurious penicillin allergy, and evaluate the safety of direct oral penicillin challenge in 'low risk' patients (b) appraise the place for a clinical pharmacist-led penicillin allergy de-labelling programme. Method Narrative review. Search engines: PubMed, Google Scholar and Cochrane reviews. Search criteria: English language; search terms: penicillin allergy, antimicrobial stewardship, antimicrobial resistance, clostridium difficile, vancomycin resistant enterococci, risk stratification, clinical pharmacist and direct oral provocation test Results Penicillin allergy labels are associated with: longer hospital stay, higher readmission rates, enhanced risk of surgical site infections, risk of Clostridioides difficile infection and Methicillin resistant Staphylococcus aureus infection, a delay in the first dose of an antibiotic in sepsis and higher healthcare costs. A direct oral penicillin challenge in 'low risk' patients has proven to be safe. Discussion Recent studies including those led by a clinical pharmacist have demonstrated safety of a direct oral penicillin challenge in 'low risk' patients. This intervention needs validation within individual health services. Conclusion Direct oral penicillin challenge reduces the adverse impact of spurious penicillin allergy. A pharmacist-led penicillin allergy de-labelling program needs further validation in prospective multi-centre studies.

Is direct oral amoxicillin challenge a viable approach for 'low-risk' patients labelled with penicillin allergy?

Spurious penicillin allergy (PenA) is a major public health problem. Up to 10% of the population and 20% of inpatients are labelled with PenA, but only <5%-10% have a proven allergy following comprehensive investigations. PenA tests are labour intensive and require specialist input, which may not be readily available due to limited allergy services. Therefore, patients with PenA receive alternative antibiotics that are associated with higher rates of iatrogenic infections, antimicrobial resistance and a longer hospital stay with consequent increased costs. Recent evidence suggests that a supervised 'direct' oral amoxicillin challenge (without performing allergy tests) is a safe option in low-risk patients (those least likely to be allergic based on history). Patient selection for this procedure is based on a careful guideline-based risk stratification process. Further research is needed to validate this intervention in routine clinical practice and explore potential facilitators and barriers to implementation in different healthcare settings.

Idiopathic anaphylaxis

Idiopathic anaphylaxis (IA) or spontaneous anaphylaxis is a diagnosis of exclusion when no cause can be identified. The exact incidence and prevalence of IA are not known. The clinical manifestations of IA are similar to other known causes of anaphylaxis. A typical attack is usually acute in onset and can worsen over minutes to a few hours. The pathophysiology of IA has not yet been fully elucidated, although an IgE-mediated pathway by hitherto unidentified trigger/s might be the main underlying mechanism. Elevated concentrations of urinary histamine and its metabolite, methylimidazole acetic acid, plasma histamine and serum tryptase have been reported, consistent with mast cell activation. There is some evidence that corticosteroids reduce the frequency and severity of episodes of IA, consistent with a steroid-responsive condition. Important differential diagnoses of IA include galactose alpha-1,3 galactose (a carbohydrate contained in red meat) allergy, pigeon tick bite (Argax reflexus), wheat-dependent exercise-induced anaphylaxis, Anisakis simplex allergy and mast cell disorders. Other differential diagnoses include "allergy-mimics" such as asthma masquerading as anaphylaxis, undifferentiated somatoform disorder, panic attacks, globus hystericus, vocal cord dysfunction, scombroid poisoning, vasoactive amine intolerance, carcinoid syndrome and phaeochromocytoma. Acute treatment of IA is the same as for other forms of anaphylaxis. Long-term management is individualized and dictated by frequency and severity of symptoms and involves treatment with H1 and H2 receptor blockers, leukotriene receptor antagonist and consideration for prolonged reducing courses of oral corticosteroids. Patients should possess an epinephrine autoinjector with an anaphylaxis self-management plan. There are anecdotal reports regarding the use of omalizumab. For reasons that remain unclear, the prognosis of IA is generally favourable with appropriate treatment and patient education. If remission cannot be achieved, the diagnosis should be reconsidered.

Biomarkers in Human Anaphylaxis: A Critical Appraisal of Current Evidence and Perspectives

Anaphylaxis is a type I hypersensitivity reaction that is potentially fatal if not promptly treated. It is a clinical diagnosis, although measurement of serial serum total mast cell tryptase (MCT) is gold standard and may help differentiate anaphylaxis from its mimics. The performance characteristics of MCT assays in anaphylaxis has been variable in previous studies, due to multiple factors including differences in the definition of anaphylaxis, methods of MCT interpretation, clinical setting of anaphylaxis, causative agents, and timing of blood sample. An international consensus equation for MCT to interpret mast cell activation has been proposed and recently validated in the context of peri-operative anaphylaxis during general anesthesia. There has been an interest in the detection of newer biomarkers in anaphylaxis including platelet activation factor (PAF), chymase, carboxypeptidase A3, dipeptidyl peptidase I (DPPI), basogranulin, and CCL-2. The key determinants of an ideal biomarker in anaphylaxis are half-life, sample handling and processing requirements, and cost. There may be a role for metabolomics and systems biology in the exploration of novel biomarkers in anaphylaxis. Future studies applying these approaches might provide greater insight into factors determining severity, clinical risk stratification, identification of mast cell disorders and improving our understanding of this relatively complex acute immunological condition. Post mortem MCT evaluation is used in Forensic Medicine during autopsy for cases involving sudden death or suspected anaphylaxis. Interpretation of post mortem MCT is challenging since there is limited published evidence and the test is confounded by multiple variables largely linked to putrefaction and site of sampling. Thus, there is no international consensus on a reference range. In this state of the art review, we will focus on the practical challenges in the laboratory diagnosis of anaphylaxis and critically appraise (a) performance characteristics of MCT in anaphylaxis in different clinical scenarios (b) the role for novel biomarkers and (c) post mortem MCT and its role in fatal anaphylaxis.

Enhancing antibiotic stewardship by tackling "spurious" penicillin allergy

Approximately 90-99% of patients with a label of penicillin allergy (PenA) are not allergic when comprehensively investigated. An inaccurate label of PenA has major public health implications-longer hospital stay, more frequent hospital admissions, greater use of fluoroquinolones, glycopeptides, cephalosporins and other expensive antibiotics resulting in significantly higher costs to the health service and predisposing to Clostridium difficile, methicillin-resistant Staphylococcus aureus infections and vancomycin-resistant enterococcus. We describe lessons learnt from recent studies regarding possible reasons contributing to an inaccurate label of PenA as well as propose a concerted multidisciplinary approach to address this important public health problem. Given the unmet need for allergy services in the UK and several other countries and knowledge gaps regarding PenA amongst healthcare professionals, we describe the potential role for a computerized clinical decision support system to enable non-specialists rapidly identify and de-label "low-risk" hospitalized patients with a label of PenA thereby obviating the need for allergy tests. This approach however needs rigorous evaluation for feasibility, safety, patient and physician acceptability, cost-effectiveness and its compatibility with information technology systems currently employed in the health service.

Anaphylaxis and Clinical Utility of Real-World Measurement of Acute Serum Tryptase in UK Emergency Departments

BACKGROUND

British guidelines recommend that serial acute serum tryptase measurements be checked in all adults and a subset of children presenting with anaphylaxis. This is the first study reporting the clinical utility of acute serum tryptase in a "real-world" emergency department (ED) setting following the publication of the World Allergy Organization (WAO) criteria for anaphylaxis.

OBJECTIVES

To (1) assess sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of acute serum tryptase in anaphylaxis; (b) determine factors associated with higher acute serum tryptase levels; and (c) audit compliance of acute serum tryptase measurement in the ED.

METHODS

The methods used were retrospective electronic search for ED admissions to 3 acute care hospitals in Birmingham, UK, with anaphylaxis in 2012 using wide search terms followed by scrutiny of electronic clinical records and application of the WAO diagnostic criteria for anaphylaxis. Patients with an acute serum tryptase measurement were included in the analysis.

RESULTS

Acute serum tryptase level was measured in 141 of 426 (33.1%) cases. Mean time from the onset of symptoms to the measurement of acute serum tryptase level was 4 hours 42 minutes (SD ± 05:03 hours) and no patients had serial measurements conforming to British guidelines. Acute serum tryptase level of more than 12.4 ng/mL (75th centile) was associated with a sensitivity, specificity, PPV, and NPV of 28%, 88%, 0.93, and 0.17, respectively. Multiple regression analysis showed that male sex (odds ratio, 2.66; P = .003) and hypotension (odds ratio, 7.08; P = .001) predicted higher acute serum tryptase level.

CONCLUSIONS

An acute serum tryptase level of more than 12.4 ng/mL in an ED setting carries high PPV and specificity, but poor sensitivity and NPV.

The concordance between component tests and clinical history in British adults with suspected pollen-food syndrome to peanut and hazelnut

BACKGROUND

Mild oropharyngeal symptoms to peanut/hazelnut occur in ~30% of patients with pollen-food syndrome (PFS). Component tests are considered a useful adjunct to the diagnosis and may help differentiate PFS from those at a risk of anaphylaxis due to storage protein/lipid transfer protein (LTP) sensitisation.

AIMS

To assess concordance between component tests and clinical history in suspected PFS to peanut/hazelnut in a specialist clinic.

METHODS

Adult patients were classified into PFS (group 1, n=69) and PFS with mild systemic symptoms (group 2, n=45) based on clinical history. Specific IgE (sIgE) of ≥0.35 kUA/L was considered positive as per manufacturers' recommendation. Kappa (κ) inter-rater agreement was calculated for concordance between clinical classification and test profiles.

RESULTS

Group 1 hazelnut: 85% monosensitised to Cor a1, 12% to storage protein/s or LTP and 3% negative to all components. Group 1 peanut: 41% monosensitised to Ara h8, 44% to storage protein/s or ±LTP and 15% negative to all components. Group 2 hazelnut: 67% monosensitised to Cor a1, 16% sensitised to storage protein/s and 17% negative to all components. Group 2 peanut: 19% monosensitised to Ara h8, 62% sensitised to storage protein/s and/or LTP and 19% negative to all components.SIgE to Ara h8 and Cor a1 were greater in group 1 versus group 2: (median (IQR) kUA/L; hazelnut: 12.1 (7.8-25.2) vs 2.4 (0.36-6.3), p<0.001; peanut: 2.4 (0.10-21.1) vs 0.3 (0-3), p<0.01)).

CONCLUSION

Concordance between component tests and clinical history for adults with PFS was good for hazelnut (κ=0.63) but poor for peanut (κ=-0.12). Food challenges are warranted in discordant cases for an accurate diagnosis.

Management of allergy to penicillins and other beta-lactams

The Standards of Care Committee of the British Society for Allergy and Clinical Immunology (BSACI) and an expert panel have prepared this guidance for the management of immediate and non-immediate allergic reactions to penicillins and other beta-lactams. The guideline is intended for UK specialists in both adult and paediatric allergy and for other clinicians practising allergy in secondary and tertiary care. The recommendations are evidence based, but where evidence is lacking, the panel reached consensus. During the development of the guideline, all BSACI members were consulted using a Web-based process and all comments carefully considered. Included in the guideline are epidemiology of allergic reactions to beta-lactams, molecular structure, formulations available in the UK and a description of known beta-lactam antigenic determinants. Sections on the value and limitations of clinical history, skin testing and laboratory investigations for both penicillins and cephalosporins are included. Cross-reactivity between penicillins and cephalosporins is discussed in detail. Recommendations on oral provocation and desensitization procedures have been made. Guidance for beta-lactam allergy in children is given in a separate section. An algorithm to help the clinician in the diagnosis of patients with a history of penicillin allergy has also been included.

Multi-centre retrospective analysis of anaphylaxis during general anaesthesia in the United Kingdom: aetiology and diagnostic performance of acute serum tryptase

This is the first multi-centre retrospective survey from the United Kingdom to evaluate the aetiology and diagnostic performance of tryptase in anaphylaxis during general anaesthesia (GA). Data were collected retrospectively (2005-12) from 161 patients [mean ± standard deviation (s.d.), 50 ± 15 years] referred to four regional UK centres. Receiver operating characteristic curves (ROC) were constructed to assess the utility of tryptase measurements in the diagnosis of immunoglobulin (Ig)E-mediated anaphylaxis and the performance of percentage change from baseline [percentage change (PC)] and absolute tryptase (AT) quantitation. An IgE-mediated cause was identified in 103 patients (64%); neuromuscular blocking agents (NMBA) constituted the leading cause (38%) followed by antibiotics (8%), patent blue dye (6%), chlorhexidine (5%) and other agents (7%). In contrast to previous reports, latex-induced anaphylaxis was rare (0·6%). A non-IgE-mediated cause was attributed in 10 patients (6%) and no cause could be established in 48 cases (30%). Three serial tryptase measurements were available in 34% of patients and a ROC analysis of area under the curve (AUC) showed comparable performance for PC and AT. A ≥ 80% PPV for identifying an IgE-mediated anaphylaxis was achieved with a PC of >141% or an AT of >15·7 mg/l. NMBAs were the leading cause of anaphylaxis, followed by antibiotics, with latex allergy being uncommon. Chlorhexidine and patent blue dye are emerging important health-care-associated allergens that may lead to anaphylaxis. An elevated acute serum tryptase (PC >141%, AT >15·7 mg/l) is highly predictive of IgE-mediated anaphylaxis, and both methods of interpretation are comparable.

A real-time prospective evaluation of clinical pharmaco-economic impact of diagnostic label of 'penicillin allergy' in a UK teaching hospital

AIMS

To perform a pharmaco-economic analysis of prescribing alternative antibiotics in patients with a diagnostic label of 'penicillin allergy' and assess whether collation of information from a structured history and liaison with the family physician could reduce costs.

METHODS

A prospective pro-forma-based interview of randomly selected in-patients and their family physician was used to assess the validity of the diagnostic label of 'penicillin allergy'. Cost analysis of prescription of alternative antibiotics was performed and compared with first-line agents.

RESULTS

102 patients were assessed and only 40% (n=41) were found to have a history consistent with penicillin hypersensitivity, 40% (n=41) were likely 'not allergic' and 20% (n=20) had 'indeterminate' reactions. Total cost of antibiotics prescribed for patients with penicillin allergy was 1.82-2.58-fold higher than for first-line antibiotics.

CONCLUSIONS

Obtaining a structured history from the patient and family physician alone can enable an accurate identification of penicillin allergy status. Total acquisition cost of second-line antibiotics is higher than if these patients were prescribed first-line antibiotics.

A UK national survey of investigations for beta-lactam hypersensitivity - heterogeneity in practice and a need for national guidelines - on behalf of British Society for Allergy and Clinical Immunology (BSACI)

BACKGROUND

Beta lactams (BL) are the most widely prescribed antibiotics in the UK and the commonest cause of hypersensitivity reactions. There are no UK guidelines for BL testing and the most relevant guidelines were devised by the European Network for Drug Allergy (ENDA) on behalf of the European Academy of Allergy and Clinical Immunology.

OBJECTIVE

Delivery of allergy services differs across Europe, so this survey was designed to investigate how closely UK practice adhered to these guidelines.

METHODS

An online survey, using surveymonkey.com software, was sent to all consultants offering an allergy service in the UK and who were members of either BSACI or 'Travellers' (Immunology consultant group).

RESULTS

The response rate was 48% (n=81/165) and BL allergy testing was undertaken by 78% of respondents. All responders requested SsIgE, although four responders stated they rarely requested. Skin testing was undertaken by 87% of respondents who perform beta lactam testing with 17% undertaking skin prick testing (SPT) only, 77% SPT followed by intra-dermal testing (IDT) if the former were negative or indeterminate and 6% SPT and IDT in all cases. The drugs, doses and protocols for skin testing varied considerably. Drug provocation testing was undertaken by 87% of respondents who undertake beta lactam testing with significant heterogeneity in protocols. Respondents that investigated ≤ 20 patients per year demonstrated lower adherence to ENDA recommendations compared to those who saw > 20. Following positive testing, 79% advised avoidance of all penicillins only and the remainder advised additional drug avoidance.

CONCLUSION AND CLINICAL RELEVANCE

This survey revealed variation in the investigation and management of BL hypersensitivity in the UK with some centres reporting procedures that could potentially put patients at risk of anaphylaxis if allergy was falsely excluded. This survey highlights an urgent need for evidence based national guidelines and standardisation of practice.

Food-dependent exercise-induced anaphylaxis: is wheat unique?

This review draws comparisons between wheat-dependent exercise-induced anaphylaxis (WDEIA) and other food-dependent exercise-induced anaphylaxis (FDEIAs) and discusses the importance of co-factors in its pathophysiology. FDEIA remains an enigmatic condition since it was first described 30 years ago. The sporadic and unpredictable nature of its reactions has puzzled clinicians and scientists for decades, but recent studies on WDEIA have enlightened us about the pathophysiology of this condition. The identification of defined allergic epitopes such as Tri a 19, α-gliadin, β-gliadin and γ-gliadin in WDEIA enables it to become the perfect model for studying FDEIA, but WDEIA is by no means a unique condition. On a larger scale, FDEIA represents a crucial link between IgE-mediated and anaphylactoid reactions and provides supportive evidence for the concept of 'summation anaphylaxis' and the need to overcome the 'allergen threshold'. Future work should focus on identifying more of the FDEIA epitopes and understanding their distinct molecular properties. The development of a biomarker in order to identify patients susceptible to co-factor influences would be invaluable.

The United Kingdom Primary Immune Deficiency (UKPID) Registry: report of the first 4 years' activity 2008-2012

This report summarizes the establishment of the first national online registry of primary immune deficency in the United Kingdom, the United Kingdom Primary Immunodeficiency (UKPID Registry). This UKPID Registry is based on the European Society for Immune Deficiency (ESID) registry platform, hosted on servers at the Royal Free site of University College, London. It is accessible to users through the website of the United Kingdom Primary Immunodeficiency Network (www.ukpin.org.uk). Twenty-seven centres in the United Kingdom are actively contributing data, with an additional nine centres completing their ethical and governance approvals to participate. This indicates that 36 of 38 (95%) of recognized centres in the United Kingdom have engaged with this project. To date, 2229 patients have been enrolled, with a notable increasing rate of recruitment in the past 12 months. Data are presented on the range of diagnoses recorded, estimated minimum disease prevalence, geographical distribution of patients across the United Kingdom, age at presentation, diagnostic delay, treatment modalities used and evidence of their monitoring and effectiveness.

Retrospective case series analysis of penicillin allergy testing in a UK specialist regional allergy clinic

INTRODUCTION

Penicillin allergy is the most common drug allergy. Skin testing for the major (PPL) and minor determinants (MDMs) of penicillin offers increased sensitivity and specificity over in vitro testing alone. Following a worldwide absence of reagents, a new kit was licensed in the UK in 2008 (Diater, Spain) and this report evaluates its use in a UK specialist allergy clinic.

METHODS

Prospective data on 50 consecutive patients tested with the new reagents were collected. The departmental protocol is adapted from the 2003 EAACI position paper.

RESULTS

14% (7/50) and 12% (6/50) of patients were diagnosed with immediate and non-immediate reactions respectively. The negative predictive value of the PPL and MDM reagents at the neat concentration for an immediate reaction was 93% (true negatives 37, false negatives 3). Two patients experienced systemic reactions to DPT in the absence of demonstrable specific IgE. None of the patients were diagnosed using skin prick testing alone or at lower concentrations of IDT. Five patients were diagnosed at the IDT stage and two at the DPT stage in the absence of demonstrable specific IgE. Six patients were diagnosed with non-immediate reactions, two on IDT alone and four following IDT and DPT.

CONCLUSION

The new PPL and MDM determinants offer enhanced sensitivity when evaluating β-lactam hypersensitivity; however, there are limitations to the current testing regimens. The UK would benefit from local guidelines, which incorporate the new reagents and acknowledge the high amoxicillin prescription rate and the relatively lower specialist-to-patient ratio in this country.

Risk factors for systemic reactions to bee venom in British beekeepers

BACKGROUND

There is a high incidence of systemic reactions (SRs) to bee stings in beekeepers, but the factors predisposing individuals to such responses are not well understood.

OBJECTIVES

To identify factors that predispose British beekeepers to SRs and to investigate how beekeepers access specialist services after SRs to bee venom.

METHODS

A link to an online survey was published in the bimonthly magazine and on the Web site of the British Beekeepers Association. The demographic results are presented using descriptive analysis, and a logistic regression model was used to determine risk factors for SRs.

RESULTS

There were 852 responses to the questionnaire of which 63% were from male beekeepers; the most common age range was 51 to 60 years. Twenty-eight percent of all responders had experienced a large local reaction and 21% had experienced a SR. Factors that predisposed beekeepers to SRs included female sex, having a family member with bee venom allergy, more than 2 years of beekeeping before a SR, and premedication with an antihistamine before attending the hives. A total of 44% of beekeepers with SRs attended the emergency department because of their symptoms, 16.6% were reviewed by an allergy specialist, and only 18% carried an adrenaline autoinjector.

CONCLUSIONS

Logistic regression analysis identified a number of novel factors to be associated with the development of SRs. Rates of attendance at the emergency department, allergy specialist review, and carriage of adrenaline were low, highlighting a need for education in the beekeeping community and among health care professionals.

Clinical immunology review series: an approach to desensitization

Allergen immunotherapy describes the treatment of allergic disease through administration of gradually increasing doses of allergen. This form of immune tolerance induction is now safer, more reliably efficacious and better understood than when it was first formally described in 1911. In this paper the authors aim to summarize the current state of the art in immunotherapy in the treatment of inhalant, venom and drug allergies, with specific reference to its practice in the United Kingdom. A practical approach has been taken, with reference to current evidence and guidelines, including illustrative protocols and vaccine schedules. A number of novel approaches and techniques are likely to change considerably the way in which we select and treat allergy patients in the coming decade, and these advances are previewed.

Wheat dependent exercise induced anaphylaxis: is this an appropriate terminology?

BACKGROUND

The presentation of wheat dependent exercise induced anaphylaxis (WDEIA) can be variable. A high index of clinical suspicion is required to initiate the investigation pathway. Double blind placebo controlled food-exercise challenge is the gold standard investigation but the practicality of this test limits its application.

AIM

To critically analyse the symptoms of WDEIA and their correlation with serum specific IgE (sIgE) to romega-5-gliadin.

METHODS

17 patients were tested for serum sIgE to romega-5-gliadin. The clinical response to a diet/exercise intervention protocol was used to assess specificity of a positive sIgE to romega-5-gliadin. Length of time to diagnosis, clinical likelihood scores, exercise intensity involved and the severity of allergic reactions were examined retrospectively.

RESULT

8/10 patients with positive sIgE to romega-5-gliadin had a confirmed diagnosis of WDEIA. Half of the WDEIA patients had a prolonged time lag to diagnosis (32-62 months) and were initially diagnosed with idiopathic anaphylaxis or chronic idiopathic urticaria and angioedema. Only three patients had experienced life threatening symptoms (Mueller grading 4). A close association was observed between requirements of lower exercise intensity to provoke a reaction and diagnostic delay.

CONCLUSION

Specific IgE to romega-5-gliadin can provide supportive evidence for WDEIA without the need of a food-exercise challenge. The wheat-exercise association is not obvious in many patients, highlighting the need to consider WDEIA in the differential diagnosis of all patients presenting with idiopathic systemic reactions. The term anaphylaxis may be inappropriate and it is therefore worth considering an alternative terminology such as 'activity dependent wheat allergy' to describe this condition.

Practice of venom immunotherapy in the United Kingdom: a national audit and review of literature

BACKGROUND

Venom immunotherapy (VIT) is the only effective treatment for prevention of serious allergic reactions to bee and wasp stings in sensitized individuals. However, controversies exist relating to diagnosis, indications for treatment and treatment schedules. We audited current practice of VIT in the United Kingdom to evaluate adherence to international guidelines.

METHODS

An online questionnaire was sent to all clinicians practising immunotherapy identified on the British Society of Allergy and Clinical Immunology website. Eighty-six questionnaires were sent and 53 responses (61.6%) were received. Of these, 48 (85%) carried out VIT at their centre.

RESULTS

Skin prick tests (SPT) and serum venom-specific IgE (SSIgE) were equally preferred as first-line investigation. Fifty percent of the respondents perform intradermal tests if both SPT and SSIgE are negative. While 8% of respondents commence VIT in patients with negative SSIgE and a history of severe reaction, 57% prefer to repeat the tests in 6-12 months if serum tryptase is elevated. If the insect responsible is uncertain and SSIgE is detected against bee and wasp venoms, 22% of the respondents will desensitize to both while 32% initiate treatment against the venom with the higher SSIgE. A protocol of weekly up-dosing for 12 weeks is preferred for induction and only 25% of respondents have ever used rush or ultra-rush protocols. Three years is thought to be optimum duration of VIT by most (56%). Eleven percent perform sting challenges at the end of treatment. Although 47% measure SSIgE at the end of treatment, only 3% use these results as a basis for discontinuing VIT.

CONCLUSION

Currently there is considerable variation in the diagnosis and management of hymenoptera venom allergy in the United Kingdom. This audit has demonstrated that the current international guidelines for the diagnosis and management of hymenoptera venom allergy are not being followed by UK allergy practitioners.

Repeated daily exposure to 2 ppm nitrogen dioxide upregulates the expression of IL-5, IL-10, IL-13, and ICAM-1 in the bronchial epithelium of healthy human airways

BACKGROUND

Repeated daily exposure of healthy human subjects to NO2 induces an acute airway inflammatory response characterised by neutrophil influx in the bronchial mucosa

AIMS

To assess the expression of NF-kappaB, cytokines, and ICAM-1 in the bronchial epithelium.

METHODS

Twelve healthy, young non-smoking volunteers were exposed to 2 ppm of NO2/filtered air (four hours/day) for four successive days on separate occasions. Fibreoptic bronchoscopy was performed one hour after air and final NO2 exposures. Bronchial biopsy specimens were immunostained for NF-kappaB, TNF-alpha, eotaxin, Gro-alpha, GM-CSF, IL-5, -6, -8, -10, -13, and ICAM-1 and their expression was quantified using computerised image analysis.

RESULTS

Expression of IL-5, IL-10, IL-13, and ICAM-1 increased following NO2 exposure.

CONCLUSION

Upregulation of the Th2 cytokines suggests that repeated exposure to NO2 has the potential to exert a "pro-allergic" effect on the bronchial epithelium. Upregulation of ICAM-1 highlights an underlying mechanism for leucocyte influx, and could also explain the predisposition to respiratory tract viral infections following NO2 exposure since ICAM-1 is a major receptor for rhino and respiratory syncytial viruses.

Diagnostic role of tests for T cell receptor (TCR) genes

Rapid advances in molecular biological techniques have made it possible to study disease pathogenesis at a genomic level. T cell receptor (TCR) gene rearrangement is an important event in T cell ontogeny that enables T cells to recognise antigens specifically, and any dysregulation in this complex yet highly regulated process may result in disease. Using techniques such as Southern blot hybridisation, polymerase chain reaction, and flow cytometry it has been possible to characterise T cell proliferations in malignancy and in diseases where T cells have been implicated in the pathogenesis. The main aim of this article is to discuss briefly the process of TCR gene rearrangement and highlight the disorders in which expansions or clonal proliferations of T cells have been recognised. It will also describe various methods that are currently used to study T cell populations in body fluids and tissue, their diagnostic role, and current limitations of the methodology.

CD3+CD4-CD8+NK- large granular lymphocytosis with neutropenia and evidence for clonality and T-cell receptor gene rearrangement: two pediatric cases

The authors describe two pediatric cases of large granular lymphocytosis presenting early in the second decade of life with neutropenia and sepsis. They are among the youngest described in the literature. This report focuses on the advantages of detailed immunophenotypic and molecular analysis and highlights some of the controversies and uncertainties in the management of these patients, particularly the choice of immunosuppressive therapy. Immunosuppressive therapy in the two children described in this report resulted in improvement of neutropenia and clinical status, but this was not accompanied by the disappearance of the clonal population.

Could administration of bacille Calmette-Guérin vaccination at birth protect from the development of asthma and allergic diseases in the western world? Has this question been adequately investigated?

Asthma and allergic diseases are disorders with a predominant Th2 immune response and there is some evidence of an inverse correlation between incidence of tuberculosis and prevalence of allergic diseases. Skewing the immune response towards a Th1 phenotype has been shown to suppress allergic inflammation. One of the ways this could be achieved is by administration of BCG vaccination early in life. Unfortunately, studies examining the protective role of BCG vaccination early in life against development of allergic diseases have shown some conflicting results and this article critically discusses the pitfalls in the currently available data. We propose that well controlled double blind placebo-controlled multi-centre study is carried out to address this important question and if this study shows a favourable outcome simple measures such as offering BCG vaccination early in life could help reduce prevalence of allergic diseases.

Effect of ozone on bronchial mucosal inflammation in asthmatic and healthy subjects

Epidemiological studies suggestthat asthmatics are more affected by ozone than healthy people. This study tested three hypotheses (1) that short-term exposure to ozone induces inflammatory cell increases and up-regulation of vascular adhesion molecules in airway lavages and bronchial tissue 6 h after ozone exposure in healthy subjects; (2) these responses are exaggerated in subjects with mild allergic asthma; (3) ozone exacerbates pre-existent allergic airways inflammation. We exposed 15 mild asthmatic and 15 healthy subjects to 0.2 ppm of ozone or filtered air for 2 h on two separate occasions. Airway lavages and bronchial biopsies were obtained 6 h post-challenge. We found that ozone induced similar increases in bronchial wash neutrophils in both groups, although the neutrophil increase in the asthmatic group was on top of an elevated baseline. In healthy subjects, ozone exposure increased the expression of the vascular endothelial adhesion molecules P-selectin and ICAM- 1, as well as increasing tissue neutrophil and mast cell numbers. The asthmatics showed allergic airways inflammation at baseline but ozone did not aggravate this at the investigated time point. At 6 h post-ozone-exposure, we found no evidence that mild asthmatics were more responsive than healthy to ozone in terms of exaggerated neutrophil recruitment or exacerbation of pre-existing allergic inflammation. Further work is needed to assess the possibility of a difference in time kinetics between healthy and asthmatic subjects in their response to ozone.

The anti-inflammatory effects of leukotriene-modifying drugs and their use in asthma

Asthma is a chronic inflammatory disease of the airways. Anti-inflammatory drug therapy, primarily using corticosteroids, is now considered the first-line treatment in the management of all grades of asthma severity. Although corticosteroids are believed to be the most potent anti-inflammatory agents available, they do not suppress all inflammatory mediators involved in the asthmatic response. Leukotrienes, which are lipid mediators generated from the metabolism of arachidonic acid, play an important role in the pathogenesis of asthma. They produce bronchospasm, increase bronchial hyperresponsiveness, mucus production, and mucosal edema, and enhance airway smooth muscle cell proliferation and eosinophil recruitment into the airways, and their synthesis or release is unaffected by corticosteroid administration. The use of leukotriene synthesis inhibitors or leukotriene receptor antagonists as anti-inflammatory therapies in asthma has therefore been investigated. Beneficial effects of leukotriene-modifying drugs have been demonstrated in the management of all grades of asthma severity, and there is evidence that certain patient groups (such as those with exercise-induced asthma or aspirin-induced asthma) may be particularly suitable for such therapy.