EAACI Guidelines on allergen immunotherapy: IgE-mediated food allergy

Food allergy can result in considerable morbidity, impairment of quality of life, and healthcare expenditure. There is therefore interest in novel strategies for its treatment, particularly food allergen immunotherapy (FA-AIT) through the oral (OIT), sublingual (SLIT), or epicutaneous (EPIT) routes. This Guideline, prepared by the European Academy of Allergy and Clinical Immunology (EAACI) Task Force on Allergen Immunotherapy for IgE-mediated Food Allergy, aims to provide evidence-based recommendations for active treatment of IgE-mediated food allergy with FA-AIT. Immunotherapy relies on the delivery of gradually increasing doses of specific allergen to increase the threshold of reaction while on therapy (also known as desensitization) and ultimately to achieve post-discontinuation effectiveness (also known as tolerance or sustained unresponsiveness). Oral FA-AIT has most frequently been assessed: here, the allergen is either immediately swallowed (OIT) or held under the tongue for a period of time (SLIT). Overall, trials have found substantial benefit for patients undergoing either OIT or SLIT with respect to efficacy during treatment, particularly for cow's milk, hen's egg, and peanut allergies. A benefit post-discontinuation is also suggested, but not confirmed. Adverse events during FA-AIT have been frequently reported, but few subjects discontinue FA-AIT as a result of these. Taking into account the current evidence, FA-AIT should only be performed in research centers or in clinical centers with an extensive experience in FA-AIT. Patients and their families should be provided with information about the use of FA-AIT for IgE-mediated food allergy to allow them to make an informed decision about the therapy.

Allergen immunotherapy for allergic rhinoconjunctivitis: A systematic review and meta-analysis

BACKGROUND

The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of developing Guidelines on Allergen Immunotherapy (AIT) for Allergic Rhinoconjunctivitis. To inform the development of clinical recommendations, we undertook a systematic review to assess the effectiveness, cost-effectiveness, and safety of AIT in the management of allergic rhinoconjunctivitis.

METHODS

We searched nine international biomedical databases for published, in-progress, and unpublished evidence. Studies were independently screened by two reviewers against predefined eligibility criteria and critically appraised using established instruments. Our primary outcomes of interest were symptom, medication, and combined symptom and medication scores. Secondary outcomes of interest included cost-effectiveness and safety. Data were descriptively summarized and then quantitatively synthesized using random-effects meta-analyses.

RESULTS

We identified 5960 studies of which 160 studies satisfied our eligibility criteria. There was a substantial body of evidence demonstrating significant reductions in standardized mean differences (SMD) of symptom (SMD -0.53, 95% CI -0.63, -0.42), medication (SMD -0.37, 95% CI -0.49, -0.26), and combined symptom and medication (SMD -0.49, 95% CI -0.69, -0.30) scores while on treatment that were robust to prespecified sensitivity analyses. There was in comparison a more modest body of evidence on effectiveness post-discontinuation of AIT, suggesting a benefit in relation to symptom scores.

CONCLUSIONS

AIT is effective in improving symptom, medication, and combined symptom and medication scores in patients with allergic rhinoconjunctivitis while on treatment, and there is some evidence suggesting that these benefits are maintained in relation to symptom scores after discontinuation of therapy.

Allergen immunotherapy for IgE-mediated food allergy: a systematic review and meta-analysis

BACKGROUND

The European Academy of Allergy and Clinical Immunology (EAACI) is developing Guidelines for Allergen Immunotherapy (AIT) for IgE-mediated Food Allergy. To inform the development of clinical recommendations, we sought to critically assess evidence on the effectiveness, safety and cost-effectiveness of AIT in the management of food allergy.

METHODS

We undertook a systematic review and meta-analysis that involved searching nine international electronic databases for randomized controlled trials (RCTs) and nonrandomized studies (NRS). Eligible studies were independently assessed by two reviewers against predefined eligibility criteria. The quality of studies was assessed using the Cochrane Risk of Bias tool for RCTs and the Cochrane ACROBAT-NRS tool for quasi-RCTs. Random-effects meta-analyses were undertaken, with planned subgroup and sensitivity analyses.

RESULTS

We identified 1814 potentially relevant papers from which we selected 31 eligible studies, comprising of 25 RCTs and six NRS, studying a total of 1259 patients. Twenty-five trials evaluated oral immunotherapy (OIT), five studies investigated sublingual immunotherapy, and one study evaluated epicutaneous immunotherapy. The majority of these studies were in children. Twenty-seven studies assessed desensitization, and eight studies investigated sustained unresponsiveness postdiscontinuation of AIT. Meta-analyses demonstrated a substantial benefit in terms of desensitization (risk ratio (RR) = 0.16, 95% CI 0.10, 0.26) and suggested, but did not confirm sustained unresponsiveness (RR = 0.29, 95% CI 0.08, 1.13). Only one study reported on disease-specific quality of life (QoL), which reported no comparative results between OIT and control group. Meta-analyses revealed that the risk of experiencing a systemic adverse reaction was higher in those receiving AIT, with a more marked increase in the risk of local adverse reactions. Sensitivity analysis excluding those studies judged to be at high risk of bias demonstrated the robustness of summary estimates of effectiveness and safety of AIT for food allergy. None of the studies reported data on health economic analyses.

CONCLUSIONS

AIT may be effective in raising the threshold of reactivity to a range of foods in children with IgE-mediated food allergy whilst receiving (i.e. desensitization) and post-discontinuation of AIT. It is, however, associated with a modest increased risk in serious systemic adverse reactions and a substantial increase in minor local adverse reactions. More data are needed in relation to adults, long term effects, the impact on QoL and the cost-effectiveness of AIT.

A new framework for the interpretation of IgE sensitization tests

IgE sensitization tests, such as skin prick testing and serum-specific IgE, have been used to diagnose IgE-mediated clinical allergy for many years. Their prime drawback is that they detect sensitization which is only loosely related to clinical allergy. Many patients therefore require provocation tests to make a definitive diagnosis; these are often expensive and potentially associated with severe reactions. The likelihood of clinical allergy can be semi-quantified from an IgE sensitization test results. This relationship varies though according to the patients' age, ethnicity, nature of the putative allergic reaction and coexisting clinical diseases such as eczema. The likelihood of clinical allergy can be more precisely estimated from an IgE sensitization test result, by taking into account the patient's presenting features (pretest probability). The presence of each of these patient-specific factors may mean that a patient is more or less likely to have clinical allergy with a given test result (post-test probability). We present two approaches to include pretest probabilities in the interpretation of results. These approaches are currently limited by a lack of data to allow us to derive pretest probabilities for diverse setting, regions and allergens. Also, cofactors, such as exercise, may be necessary for exposure to an allergen to result in an allergic reaction in specific IgE-positive patients. The diagnosis of IgE-mediated allergy is now being aided by the introduction of allergen component testing which may identify clinically relevant sensitization. Other approaches are in development with basophil activation testing being closest to clinical application.

EAACI IG Biologicals task force paper on the use of biologic agents in allergic disorders

Biologic agents (also termed biologicals or biologics) are therapeutics that are synthesized by living organisms and directed against a specific determinant, for example, a cytokine or receptor. In inflammatory and autoimmune diseases, biologicals have revolutionized the treatment of several immune-mediated disorders. Biologicals have also been tested in allergic disorders. These include agents targeting IgE; T helper 2 (Th2)-type and Th2-promoting cytokines, including interleukin-4 (IL-4), IL-5, IL-9, IL-13, IL-31, and thymic stromal lymphopoietin (TSLP); pro-inflammatory cytokines, such as IL-1β, IL-12, IL-17A, IL-17F, IL-23, and tumor necrosis factor (TNF); chemokine receptor CCR4; and lymphocyte surface and adhesion molecules, including CD2, CD11a, CD20, CD25, CD52, and OX40 ligand. In this task force paper of the Interest Group on Biologicals of the European Academy of Allergy and Clinical Immunology, we review biologicals that are currently available or tested for the use in various allergic and urticarial pathologies, by providing an overview on their state of development, area of use, adverse events, and future research directions.

EAACI IG Biologicals task force paper on the use of biologic agents in allergic disorders

Biologic agents (also termed biologicals or biologics) are therapeutics that are synthesized by living organisms and directed against a specific determinant, for example, a cytokine or receptor. In inflammatory and autoimmune diseases, biologicals have revolutionized the treatment of several immune-mediated disorders. Biologicals have also been tested in allergic disorders. These include agents targeting IgE; T helper 2 (Th2)-type and Th2-promoting cytokines, including interleukin-4 (IL-4), IL-5, IL-9, IL-13, IL-31, and thymic stromal lymphopoietin (TSLP); pro-inflammatory cytokines, such as IL-1β, IL-12, IL-17A, IL-17F, IL-23, and tumor necrosis factor (TNF); chemokine receptor CCR4; and lymphocyte surface and adhesion molecules, including CD2, CD11a, CD20, CD25, CD52, and OX40 ligand. In this task force paper of the Interest Group on Biologicals of the European Academy of Allergy and Clinical Immunology, we review biologicals that are currently available or tested for the use in various allergic and urticarial pathologies, by providing an overview on their state of development, area of use, adverse events, and future research directions.

EAACI food allergy and anaphylaxis guidelines: diagnosis and management of food allergy

Food allergy can result in considerable morbidity, impact negatively on quality of life, and prove costly in terms of medical care. These guidelines have been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Guidelines for Food Allergy and Anaphylaxis Group, building on previous EAACI position papers on adverse reaction to foods and three recent systematic reviews on the epidemiology, diagnosis, and management of food allergy, and provide evidence-based recommendations for the diagnosis and management of food allergy. While the primary audience is allergists, this document is relevant for all other healthcare professionals, including primary care physicians, and pediatric and adult specialists, dieticians, pharmacists and paramedics. Our current understanding of the manifestations of food allergy, the role of diagnostic tests, and the effective management of patients of all ages with food allergy is presented. The acute management of non-life-threatening reactions is covered in these guidelines, but for guidance on the emergency management of anaphylaxis, readers are referred to the related EAACI Anaphylaxis Guidelines.

Moving from peanut extract to peanut components: towards validation of component-resolved IgE tests

BACKGROUND

Replacement of peanut extracts by recombinant peanut components is an important step in allergy serologic testing. Criteria are needed for the unbiased inclusion of patients into a study to validate such a replacement.

METHODS

Plasma samples from 64 peanut-positive children (42 reactors, 22 nonreactors in a double-blind, placebo-controlled food challenge) were used to compare IgE reactivity to six recombinant peanut allergens with reactivity to natural peanut proteins extracted at neutral or low pH. We tested the hypothesis that poor extractability of Ara h 9 and other basic allergens at neutral pH leads to under-representation of patients with such sensitization.

RESULTS

IgE reactivity to the components did not fully explain IgE reactivity to peanut extract in 5 of 32 reactors with IgE to peanut extract ≤100 kUA /l. IgE reactivity to components was stronger than to the extract in 11 plasma samples, which was largely due to a low Ara h 8 reactivity of the extract. IgE reactivity to Ara h 9 was much lower than reactivity to other basic proteins, some of which bound IgE well in the RAST, but lost IgE reactivity upon immunoblotting.

CONCLUSIONS

Conventional peanut extracts are deficient in significant IgE-binding components. The inclusion of patients for a validation study should be based on serology performed with improved peanut reagents to avoid a bias against these under-represented, potentially important allergens. To judge clinical relevance of an allergen, the reagent used for inclusion of patients needs to be efficient in detecting IgE to this component.

Genetic associations between behavioral traits and direct-social effects of growth rate in pigs

This study examined the behavioral consequences of selecting pigs using a social genetic model for growth. Calculations enable each member of a group of pigs to be given a direct breeding value (DBV) and a social breeding value (SBV), which can be summarized into a total breeding value (TBV) for growth. Selection for growth TBV could affect animal behavior because social effects account for within-group interactions. Data were recorded from 96 groups of Yorkshire and Yorkshire × Landrace pigs in a nucleus herd. Each group contained 15 pigs fed ad libitum from 2 feeders; the space allowance was 0.85 m2/pig. Average daily gain was quantified from 35 to 100 kg of BW. Fighting and bullying activity at mixing (period 1), lying frequency 3 wk after mixing (period 2), and counts of skin lesions in periods 1 and 2 were recorded. The DBV for these traits were estimated with a classic animal model. We simulated different correlations between the direct genetic effect and the social genetic effect on growth rate (r(DS)), 2 components that respectively determine a pig's genetic capacity to grow and its genetic influence on growth of group mates: r(DS) was successively assumed to be 0 and ±0.12, ±0.20, ±0.29, and ±0.58. Finally, the correlations between DBV, SBV, and TBV for ADG, as well as the DBV for behavior and skin lesions, were calculated and tested for a level of significance at P < 0.05. The gradient from negative to positive values of r(DS) refers to a progressive path running from genetic antagonism to genetic mutualism for growth. If rDS in the population truly ranged between -0.58 and -0.20, correlations for TBV for ADG with DBV for fighting and bullying progressively increased with rDS. Consequently, if rDS was low (between -0.12 and +0.12) or positive (>+0.12), pigs with high TBV for ADG had higher DBV for bullying other pigs in the group and for fighting than pigs with lower TBV for ADG. Pigs with high TBV for ADG did not differ from other pigs in their DBV for lesions to the anterior part of the body, but they had a lower DBV for posterior lesions, whereas in period 2, they had higher DBV for posterior lesions and lower DBV for lying. Under genetic mutualism for growth and in housing conditions similar to those in the present study, selection for growth TBV would promote the rapid establishment of the dominance relationships, with more aggressive contests among group mates at mixing. Pigs would subsequently be more active but, judging by skin lesions, less willing to fight in a more stable social situation.

Salivary gland and peripheral blood T helper 1 and 2 cell activity in Sjögren's syndrome compared with non-Sjögren's sicca syndrome

OBJECTIVES

To investigate whether differences in T helper (Th) 1 and Th2 cell activity in salivary glands ("local") or ("peripheral") blood can discriminate between Sjögren's syndrome (SS) and non-Sjögren's sicca syndrome (nSS-sicca). Additionally, to study relationships of local and peripheral Th cell activities with each other and with disease activity measures.

METHODS

62 sicca patients (32 with SS, 30 with nSS-sicca) were studied. Local Th1 (interferon gamma (IFNgamma)) and Th2 (interleukin (IL) 4) activity were determined using immunohistochemistry. T cell production of IFNgamma and IL4 in peripheral blood (PB) was determined by ELISA. Erythrocyte sedimentation rate (ESR) and serum IgG were considered disease activity measures.

RESULTS

ESR and serum IgG were higher in patients with SS than in patients with nSS-sicca. Local Th1 cell activity was higher and PB Th1 activity lower in patients with SS than in those with nSS-sicca. Th2 cell activity did not differ significantly between the patient groups. The ratio IFNgamma/IL4 was higher in salivary glands and lower in PB in patients with SS than in patients with nSS-sicca. Local and peripheral Th1 and Th2 cell activities correlated with ESR and serum IgG levels. ESR, serum IgG, and local or peripheral Th1 or Th2 cell activity did not discriminate between patients with SS and nSS-sicca.

CONCLUSIONS

An imbalance between Th1 and Th2 activity in sicca patients is clearly related to the severity of disease, but cannot be used to distinguish between patients with SS and those with nSS-sicca.

Whole blood and plasma water in health and disease: longitudinal and transverse observations and correlations with several different hematological and clinicochemical parameters

In a healthy reference population, hemoglobin (Hgb) and hematocrit (Hct) have been proposed as surrogate markers for whole blood water (WBW). We have extended this study under different physiological and pathological conditions in two longitudinal series, viz. (1) acute hyper- and hypohydration experiments in a healthy individual and (2) three athletes running 5 km each, and in three transverse series, viz. (3) a young reference population (n = 97, 49 females), (4) an old reference population (n = 37, nine females) consisting of inhabitants of a nursing home and (5) cardiac, hematological and renal patients including severe anaemia, polycythaemia and abnormal protein levels (n = 50, 25 females) with suspected hydration disturbances. The only sex difference found was a lower WBW in males in the young reference group. The percentage change of PW was less than that of WBW. In all five groups together (n = 293) WBW correlated closely (P < 0.0001) with Hgb and Hct (both r = -0.95) and with erythrocyte count (r = -0.85), whereas PW correlated with total protein (Tprot) (r = -0.84). In the longitudinally studied groups (1) and (2) WBW also correlated (P < 0.0001) with cholesterol, Ca, Tprot, albumin, platelets, globulin and white blood cells (r +/- 0.98-0.37), while PW correlated (P < 0.0001) not only with the same clinicochemical parameters but also with Hct, Hgb and red blood cells (r +/- 0.98-0.44). The homeostasis of PW is more narrowly regulated than that of WBW. Hgb, Hct and erythrocyte count reflect WBW and Tprot reflects PW also under disease conditions. WBW (mass%) can be calculated from Hgb and Hct using the formulae: -0.09 x Hgb (g/l) + 91.7 and -28.6 x Hct (v/v) + 91.8 and PW (mass%) from Tprot using the formula: -0.09 x Tprot (g/l) + 97.6. Other correlations were observed only in a longitudinal setting and presumably are due to concentration and dilution.

Interleukin-3 treatment of rhesus monkeys leads to increased production of histamine-releasing cells that express interleukin-3 receptors at high levels

To understand the hematopoietic and nonhematopoietic responses to interleukin-3 (IL-3), expression of cell-surface IL-3 receptors (IL-3R) was examined on bone marrow (BM) cells and peripheral blood (PB) cells of rhesus monkeys during the course of in vivo IL-3 treatment. Whereas IL-3R expression is low in untreated monkeys, IL-3 administration led to a gradual increase in both low- and high-affinity binding sites for IL-3. This increase reflected the total number of cells expressing IL-3Rs, as detected by flow cytometry using biotinylated IL-3. Most of these IL-3R+ cells in both BM and PB could be characterized as basophilic granulocytes that contained high levels of histamine. In contrast to the effect on these differentiated cells, IL-3 administration did not significantly alter the low level IL-3R expression on immature, CD34+ cells. Further flow cytometric analysis using biotinylated growth factors showed that the IL-3R+ basophils also expressed receptors for granulocyte-macrophage colony-stimulating factor (GM-CSF), but not for IL-6 or Kit ligand. These findings indicated that the IL-3R+ cells included neither monocytes, which express GM-CSFRs and IL-6Rs abundantly, nor mast cells, which express c-kit. By combining flow cytometric and Scatchard data, it was calculated that the basophils contain as many as 1 to 2 x 10(3) high-affinity IL-3Rs and 15 to 30 x 10(3) low-affinity sites. The finding that in vivo IL-3 treatment leads to the production of large numbers of cells that express high levels of IL-3R and are capable of producing histamine provides an explanation for the often severe allergic reactions that occur during prolonged IL-3 administration. It also indicates that IL-3, in addition to its direct effects on hematopoietic cells, may also stimulate hematopoiesis through the release of secondary mediators such as histamine by IL-3-responsive mature cells.

Highly increased production of bone marrow-derived blood cells by administration of homologous interleukin-3 to rhesus monkeys

Recombinant rhesus monkey interleukin-3 (IL-3) was administered to normal rhesus monkeys in graded doses ranging from 3 to 30 micrograms/kg/d subcutaneously for 30 consecutive days or given as a continuous intravenous infusion at a dose of 30 micrograms/kg/d for 16 days. After a lag phase of about 1 week, a highly increased, dose-dependent production of bone marrow-derived blood cells was observed, preceded by amplification of bone marrow hematopoietic progenitor cells. Simultaneously, peripheral blood progenitor cells rose. The increase included basophilic, eosinophilic and neutrophilic granulocytes, monocytes, and the erythrocyte and platelet lineages. Characteristically, a T-lymphocyte response was absent. It is concluded that IL-3 in vivo stimulates blood cell production from an immature, multipotent progenitor cell.

Potentiation of glucocorticoid-induced lysis in refractory and resistant leukemia cells by inhibitors of ADP-ribosylation

Meta-iodo-benzylguanidine (MIBG; 3 x 10(-5) M), a novel inhibitor of mono(ADP-ribosylation)-and the general ribosylation inhibitor nicotinamide (NA; 5-20 mM) both stimulated the glucocorticoid-mediated lysis of sensitive L1210 leukemia cells and even induced susceptibility in various human and murine lines refractory or resistant to dexamethasone (DEX). Potentiation and induction of DEX-sensitivity by ADP-ribosylation inhibitors was accompanied by an increase in saturable 3H-DEX binding sites and by a 2-3 fold increase in the affinity of intracellular receptors for hormone binding. Moreover, the ribosylation inhibitors converted the glucocorticoid antagonist RU-486 into a potent agonist for cytolysis of L1210 cells. We conclude that the cytolytic action of glucocorticoid hormones in leukemic cells is negatively controlled by (mono)ADP-ribosylation of receptor proteins.

CT myelographic findings in degenerative disorders of the cervical spine: clinical significance

CT myelographic data in 80 patients with clinical evidence of nerve-root involvement or long tract signs attributed to degenerative disorders of the cervical spine were classed into five diagnostic groups, and their clinical significance was assessed. Unilateral flattening of the cord by a spondylotic mass or bulging disk in a normally wide canal (group 1) was considered nonspecific because nerve-root signs were nearly as often contralateral as unilateral to the radiologic findings, and none of the patients had long tract signs. As a rule, conventional myelography showed only minor root-sleeve deformity. Concentric compression of the cord in a narrow (stenotic) canal (group 2) proved to produce long tract signs only after the cross-sectional area of the cord had been reduced by about 30% to a value of about 60 mm2 or less. In most cases, nerve-root swelling (group 3) coincided with the side of nerve-root symptoms. A 100% correlation was found between the side of disk herniation with occlusion of the corresponding foramen (group 4) and the side of nerve-root symptoms. In 24 patients, cord and nerve roots showed no abnormalities (group 5). If stenosis of the spinal canal, nerve root swelling, and disk herniation are considered specific CT myelographic signs in nerve-root symptomatology, a specific diagnosis could be made in about 40% of the cases.