Eosinophilic esophagitis as a side-effect of allergen immunotherapy: protocol for a systematic review and meta-analysis

Summary

Background. Sensitization to food and airborne allergens is common in the majority of patients with eosinophilic esophagitis (EoE). Although there is not a direct cause-effect relationship of IgE-mediated allergy with the pathogenesis of EoE, there is a growing evidence that oral desensitization to food and sublingual immunotherapy (SLIT) may induce the development of EoE as an adverse effect. As part of the 'EoE and Allergen Immunotherapy (AIT)' Task Force funded by the European Academy of Allergy and Clinical Immunology (EAACI), a systematic approach will be followed to review the evidence from the published scientific literature on the development of EoE in children and adults under any type of AIT. Methods. This systematic review will be carried out following the PRISMA statement guidelines. Studies will be assessed for inclusion in the review according to the Population-Interventions-Comparators-Outcomes (PICO) criteria. Results. Expected outcomes will provide evidence on the AIT-EoE development connection. Conclusions. The findings from this review will be used as a reference to provide useful guidelines for physicians treating patients with EoE and/or are practicing AIT.

Differences in chronic spontaneous urticaria between Europe and Central/South America: results of the multi-center real world AWARE study

Background

Global chronic urticaria (CU) disease experience and management is not well documented. This study descriptively compares these aspects among CU patients residing in Europe (EU) and Central and South America (C/SA).

Methods

AWARE (A World-wide Antihistamine-Refractory chronic urticaria patient Evaluation) is a global prospective, non-interventional study of CU in the real-world setting. Patients were ≥ 18 years with a diagnosis of H1-antihistamine-refractory CU for > 2 months. Differences between the EU and C/SA regions in demographic and clinical characteristics, quality of life (QoL), work and activity impairment, pharmacological treatment, and healthcare resource use were examined.

Results

In total, 4224 patients were included in the analysis (C/SA 492; EU 3732). Rates of untreated patients were greater in the C/SA region (45.1% vs. 31.9%; P < 0.005) and escalation to third-line therapy was rare in both regions. Differences in disease experience emerged, with C/SA patients more commonly experiencing angioedema (C/SA 50.8% vs. EU 46.1%; P = 0.03) or comorbid chronic inducible urticaria (C/SA 30% vs. EU 22%; P < 0.001). Correspondingly, rates of uncontrolled urticaria were higher among C/SA patients (82.8% vs. 77.5%; P = 0.017) and patients in the C/SA region showed significantly greater work and activity impairment (absenteeism: 10.4 ± 19.7 vs. 6.7 ± 19.0, P = 0.004; presenteeism: 30.3 ± 31.9 vs. 24.4 ± 25.8, P = 0.001; work productivity loss: 33.9 ± 33.9 vs. 26.5 ± 27.5, P < 0.001; activity impairment: 37.7 ± 34.7 vs. 32.7 ± 30.1, P = 0.001). However, QoL impairment was greater in the EU region (Dermatology Life Quality Index: C/SA 6.5 ± 5.9 vs. EU 8.3 ± 7.0; P < 0.001). There was a significant difference in use of healthcare resources, including emergency services (39.6% vs. 29.3%; P < 0.001), hospitalization (7.7% vs 21.9%; P < 0.001) general practitioners (31.7% vs 57.3%; P < 0.001), and additional allergists or dermatologists (50.6% vs. 47.3%, P < 0.001), among patients in the C/SA and EU region, respectively. In both regions, patients with a primary diagnosis of CU with angioedema had significantly greater impairment in work and non-work activities and healthcare resource utilization compared to those without angioedema.

Conclusions

This study revealed that CU is a heterogeneous condition with differences in healthcare utilization and outcomes between EU and C/SA. However, overall there is a high unmet need of H1-antihistamine-refractory CU patients, which is associated with high use of healthcare resources, and has a large negative effect on QoL and work productivity.

Overview of systematic reviews in allergy epidemiology

BACKGROUND

There is a substantial body of evidence on the epidemiology of allergic conditions, which has advanced the understanding of these conditions. We aimed to systematically identify systematic reviews and meta-analyses on the epidemiology of allergic diseases to assess what has been studied comprehensively and what areas might benefit from further research.

METHODS

We searched PubMed and EMBASE up to 12/2014 for systematic reviews on epidemiological research on allergic diseases. We indexed diseases and topics covered and extracted data on the search characteristics of each systematic review.

RESULTS

The search resulted in 3991 entries after removing duplicates, plus 20 other items found via references and conference abstracts; 421 systematic reviews were relevant and included in this overview. The majority contained some evidence on asthma (72.9%). Allergic rhinitis, atopic eczema and food hypersensitivity were covered in 15.7%, 24.5% and 9.0%, respectively. Commonly studied risk factors for atopic eczema included dietary and microbial factors, while for asthma, pollution and genetic factors were often investigated in systematic reviews. There was some indication of differing search characteristics across topics.

CONCLUSION

We present a comprehensive overview with an indexed database of published systematic reviews in allergy epidemiology. We believe that this clarifies where most research interest has focussed and which areas could benefit from further research. We propose that this effort is updated every few years to include the most recently published evidence and to extend the search to an even broader list of hypersensitivity/allergic disorders.

Self-reported hair loss in patients with chronic spontaneous urticaria treated with omalizumab: an under-reported, transient side effect?

Omalizumab has been recently approved for treating patients with refractory to H1- antihistamines chronic spontaneous urticaria (CSU). Although hair loss is listed among omalizumab side effects, there are no available data to estimate its frequency. We describe for the first time hair loss as a side effect associated with omalizumab administration in three women, 38, 62 and 70 years old, suffering from refractory to H1-antihistamines CSU. This information was retrieved from their Chronic Urticaria Quality of Life Questionnaires. Despite this side effect, all patients agreed to continue omalizumab regular administration. Hair loss appeared to be transient, lasting up to four months. All cases finally benefited from omalizumab continuation.

In silico prediction of Ara h 2 T cell epitopes in peanut-allergic children

BACKGROUND

Despite the frequency and severity of peanut allergy, the only approved treatment is strict avoidance. Different types of immunotherapy with crude peanut extract are not universally effective and have been associated with relatively high adverse reaction rates.

OBJECTIVE

We sought to determine whether in silico predictive algorithms were useful in identifying candidate peptides for an Ara h 2 peptide-based vaccine using peanut-allergic patients' peripheral blood mononuclear cells (PBMCs) in vitro. A human leucocyte antigen (HLA) distribution analysis was also performed.

METHODS

Major histocompatibility complex (MHC)-class II-binding peptides were predicted using NetMHCIIpan-2.0 and NetMHCII-2.2 algorithms. PBMCs from 80 peanut-allergic patients were stimulated with overlapping 20-mer Ara h 2 peptides. Cell supernatant cytokine profiles were evaluated by multiplex assays. HLA-DRB1* and HLA-DQB1* typing were performed.

RESULTS

Four regions of overlapping sequences induced PBMC proliferation and predominant Th2 cytokine production. HLA genotyping showed 30 different DRB1* allele specificities and eight DQ serological specificities. The in silico analysis revealed similar relevant regions and predicted identical or similar core 9-mer epitopes to those identified in vitro. If relevant peptides, as determined by either in vitro or in silico analysis (15 peptides and 9 core epitopes respectively), were used in a peptide-based vaccine, they would cover virtually all subjects in the cohort studied.

CONCLUSIONS AND CLINICAL RELEVANCE

Four dominant regions in Ara h 2 have been identified, containing sequences that could serve as potential candidates for peptide-based immunotherapy. MHC-class II-based T cell epitope prediction algorithms for HLA-DR and -DQ loci accurately predicted Ara h 2 T cell epitopes in peanut-allergic subjects, suggesting their potential utility in a peptide-based vaccine design for food allergy.

EAACI taskforce position paper: evidence for autoimmune urticaria and proposal for defining diagnostic criteria

An autoimmune subset of chronic spontaneous urticaria is increasingly being recognized internationally, based on laboratory and clinical evidence that has accrued over the last 20 years. This evidence has been reviewed by a taskforce of the Dermatology section of the European Academy of Allergy and Clinical Immunology. Functional autoantibodies in chronic urticaria (CU) patient sera have been demonstrated against IgE and FcεRIα by basophil and mast cell histamine release assays and by basophil activation assays. Antibody specificity has been confirmed by immunoassay, but there is a poor correlation between functionality and immunoreactivity. Approximately 25% of CU patients have a positive basophil histamine release assay and show autoreactivity (a positive autologous serum skin test), whereas 50% are negative regarding both. Functionality of CU sera appears to be complement dependent on mast cells but not exclusively on basophils. Basophil activation by CU sera is predominantly restricted to IgG1 and IgG3 subclasses. Circumstantial evidence for CU being an autoimmune disease comes from an observed association with other autoimmune diseases, a strong association between serum functionality and HLA-DR4 haplotype and the good response of CU patients to immunotherapies. It was proposed that a study should be undertaken to prospectively validate potentially relevant clinical criteria (from the history, examination and routinely available clinical investigations) against a new 'gold standard' for the diagnosis of ACU (positive autoreactivity, functional bioassay and immunoassay) to define preliminary criteria sets for the diagnosis of ACU based on clinical and laboratory features with highest individual sensitivity and specificity.

Dietary therapy can reverse esophageal subepithelial fibrosis in patients with eosinophilic esophagitis: a historical cohort

BACKGROUND

Fibrosis of the esophageal lamina propria is a known complication of eosinophilic esophagitis (EoE). To date, therapy with topical corticosteroids has been shown to reverse esophageal fibrosis in some patients; however, there is little evidence to suggest that dietary therapy can also reverse it. Our aim was to examine whether dietary therapy alone can reverse esophageal fibrosis in children with EoE.

METHODS

We performed a historical cohort study based on children with EoE who had esophageal fibrosis on pretreatment biopsies using trichrome staining. Post-treatment biopsies were analyzed for fibrosis reversal, and results were compared between patients treated with dietary restriction and those that received topical steroids. Clinical characteristics (age, symptoms, duration of symptoms prior to therapy, treatment type, and duration of therapy) were recorded. Histological markers (eosinophil numbers and eosinophilic degranulation in both epithelium and lamina propria, basal zone hyperplasia, and the presence of eosinophilic microabscesses in the epithelium) were examined by reviewing hematoxylin and eosin-stained biopsies and by immunohistochemical staining. These were examined as potential predictors for fibrosis reversal.

RESULTS

Fibrosis resolved following both dietary restriction and topical steroids (3/17 and 5/9 patients respectively, P = 0.078). Post-treatment symptom resolution and decreased intraepithelial eosinophil numbers were found to be the only significant predictors of fibrosis resolution.

CONCLUSIONS

Dietary restriction alone, similar to topical steroids, can reverse fibrosis in children with EoE.

Cereal pollen sensitisation in pollen allergic patients: to treat or not to treat?

Pollen allergens of the Poaceae family comprise one of the main causes of pollinosis worldwide. Although most of cereals are included in this family, certain pollination characteristics and aerobiological features differentiate them from common wild grass pollen. Cereal pollen grains cannot be easily characterised as potential sources of aero allergens, because of their pollination mode (most of them are autogamous plants), the consecutive low numbers of pollen they produce and their pollen's large volume and consequent high weight which further prevent dispersion and pollen transport. However, various epidemiologicalstudies concluded in comparable sensitisation patterns between common grass and cereal pollen. This fact can be attributed to the common epitopes shared between grass and cereal pollen allergens, which are responsible for the high cross reactivity observed not only in vitro but also in vivo. Therefore, the sensitisation patterns do not usually reflect a genuine, cereal-specific IgE recognition. On the contrary, genuine cereal sensitisation and allergy are referred to only in rare cases of occupational exposure to high amounts of these pollen grains (farmers and field workers) or in patients staying in the vicinity of cereal fields. Thus, cautious considerations should be taken into account when diagnostically approaching patients in which cereal pollen allergy could be considered in the differential diagnosis.

EAACI/GA(2)LEN task force consensus report: the autologous serum skin test in urticaria

Injection of autologous serum collected during disease activity from some patients with chronic spontaneous urticaria (CU) into clinically normal skin elicits an immediate weal and flare response. This observation provides a convincing demonstration of a circulating factor or factors that may be relevant to the understanding of the pathogenesis and management of the disease. This test has become known as the autologous serum skin test (ASST) and is now widely practised despite incomplete agreement about its value and meaning, the methodology and the definition of a positive response. It should be regarded as a test for autoreactivity rather than a specific test for autoimmune urticaria. It has only moderate specificity as a marker for functional autoantibodies against IgE or the high affinity IgE receptor (FcepsilonRI), detected by the basophil histamine release assay, but high negative predictive value for CU patients without them. It is usually negative in other patterns of CU, including those that are physically induced. Positive ASSTs have been reported in some subjects without CU, including those with multiple drug intolerance, patients with respiratory allergy and healthy controls, although the clinical implications of this are uncertain. It is essential that failsafe precautions are taken to ensure that the patient's own serum is used for skin testing and aseptic procedures are followed for sample preparation and handling. CU patients with a positive ASST (ASST(+)) are more likely to be associated with HLADR4, to have autoimmune thyroid disease, a more prolonged disease course and may be less responsive to H1-antihistamine treatment than those with a negative ASST (ASST(-)) although more evidence is needed to confirm these observations conclusively.

Food contact hypersensitivity syndrome: the mucosal contact urticaria paradigm

Oral allergy syndrome (OAS) or pollen-fruit allergy syndrome represents a mucosal allergic contact urticaria in people sensitized to common pollens, due to IgE cross-reactivity between homologous pollen allergens and various plant foods. It is the most prevalent food allergy, affecting millions of people with respiratory allergies. Usually, symptoms are mild, self-limiting and localized to the oropharyngeal mucosa, although they may sometimes become generalized and life-threatening. Although patients usually recognize the offending foods, diagnosis may sometimes be complicated. Several clinical syndromes and association between pollens and plant-derived foods have been described. Crossreactivity on the basis of stringent immunological and allergological criteria can also occur in people without pollen sensitization or concomitant respiratory allergies, as in latex-fruit syndrome. The term 'food contact hypersensitivity syndrome' (FCHS) is proposed in this paper for the first time, to include all mucosal hypersensitivity reactions presenting with contact to food (both immunological and nonimmunological), whether due to crossreactivity with homologous plant-derived allergens or not. At this time, prophylaxis and treatment can only be attained by avoidance, even when symptoms are mild, with consequent impairment in quality of life. A better understanding of the pathophysiological mechanisms of FCHS and food allergy in general is essential for deeper insights and future emergence of effective therapies.

Sandfly-fever outbreak in Cyprus: Are Phleboviruses still a health problem?

BACKGROUND

Between May and September of 2002, 256 soldiers of the Greek Army Forces in Cyprus developed a 3-day self-limited febrile illness. All clinical symptoms and laboratory findings are described.

RESULTS

The responsible agent was a Cypriot strain of sandfly fever Sicilian virus (genus Phlebovirus family Bunyaviridae), identified and isolated from the blood samples of infected individuals who were characterized by an abrupt onset of high fever, arthralgias, myalgias, headache and lower back pain, followed by a post-infectious asthenia syndrome. The major laboratory findings included leucopenia, monoytosis in blood smear and mild elevation of both the aminotransferases.

CONCLUSION

A Cypriot strain of sandfly fever Sicilian virus was responsible for a 3-day-fever syndrome among non-immune soldiers. Clinicians have to consider Sandfly fever in the differential diagnosis in patients with similar symptoms during their accommodation or just after their return from Cyprus, or any other Mediterranean countries, especially during summer when sandflies are active.