Incidence and natural history of hen's egg allergy in the first 2 years of life-the EuroPrevall birth cohort study

BACKGROUND

Parents and health staff perceive hen's egg allergy (HEA) as a common food allergy in early childhood, but the true incidence is unclear because population-based studies with gold-standard diagnostic criteria are lacking.

OBJECTIVE

To establish the incidence and course of challenge-confirmed HEA in children, from birth until the age of 24 months, in different European regions.

METHODS

In the EuroPrevall birth cohort study, children with a suspected HEA and their age-matched controls were evaluated in 9 countries, using a standardized protocol including measurement of HE-specific immunoglobulin E-antibodies in serum, skin prick tests, and double-blind, placebo-controlled food challenges (DBPCFC).

RESULTS

Across Europe, 12 049 newborns were enrolled, and 9336 (77.5%) were followed up to 2 years of age. In 298 children, HEA was suspected and DBPCFC was offered. HEA by age two was confirmed in 86 of 172 challenged children (mean raw incidence 0.84%, 95% confidence interval (95% CI) 0.67-1.03). Adjusted mean incidence of HEA was 1.23% (95% CI 0.98-1.51) considering possible cases among eligible children who were not challenged. Centre-specific incidence ranged from United Kingdom (2.18%, 95% CI 1.27-3.47) to Greece (0.07%). Half of the HE-allergic children became tolerant to HE within 1 year after the initial diagnosis.

CONCLUSIONS

The largest multinational European birth cohort study on food allergy with gold-standard diagnostic methods showed that the mean adjusted incidence of HEA was considerably lower than previously documented, although differences in incidence rates among countries were noted. Half of the children with documented HEA gained tolerance within 1 year postdiagnosis.

Dietary habits and supplement use in relation to national pregnancy recommendations: data from the EuroPrevall birth cohort

Assessing maternal dietary habits across Europe during pregnancy in relation to their national pregnancy recommendations. A collaborative, multi-centre, birth cohort study in nine European countries was conducted as part of European Union funded EuroPrevall project. Standardised baseline questionnaire data included details of food intake, nutritional supplement use, exposure to cigarette smoke during pregnancy and socio-demographic data. Pregnancy recommendations were collected from all nine countries from the appropriate national organisations. The most commonly taken supplement in pregnancy was folic acid (55.6 % Lithuania-97.8 % Spain) and was favoured by older, well-educated mothers. Vitamin D supplementation across the cohort was very poor (0.3 % Spain-5.1 % Lithuania). There were significant differences in foods consumed in different countries during pregnancy e.g. only 2.7 % Dutch mothers avoided eating peanut, while 44.4 % of British mothers avoided it. Some countries have minimal pregnancy recommendations i.e. Lithuania, Poland and Spain while others have similar, very specific recommendations i.e. UK, the Netherlands, Iceland, Greece. Allergy specific recommendations were associated with food avoidance during pregnancy [relative rate (RR) 1.18 95 % CI 0.02-1.37]. Nutritional supplement recommendations were also associated with avoidance (RR 1.08, 1.00-1.16). Maternal dietary habits and the use of dietary supplements during pregnancy vary significantly across Europe and in some instances may be influenced by national recommendations.

Incidence and natural history of challenge-proven cow's milk allergy in European children--EuroPrevall birth cohort

BACKGROUND

Cow's milk allergy (CMA) is one of the most commonly reported childhood food problems. Community-based incidence and prevalence estimates vary widely, due to possible misinterpretations of presumed reactions to milk and differences in study design, particularly diagnostic criteria.

METHODS

Children from the EuroPrevall birth cohort in 9 European countries with symptoms possibly related to CMA were invited for clinical evaluation including cows' milk-specific IgE antibodies (IgE), skin prick test (SPT) reactivity and double-blind, placebo-controlled food challenge.

RESULTS

Across Europe, 12 049 children were enrolled, and 9336 (77.5%) were followed up to 2 years of age. CMA was suspected in 358 children and confirmed in 55 resulting in an overall incidence of challenge-proven CMA of 0.54% (95% CI 0.41-0.70). National incidences ranged from 1% (in the Netherlands and UK) to <0.3% (in Lithuania, Germany and Greece). Of all children with CMA, 23.6% had no cow's milk-specific IgE in serum, especially those from UK, the Netherlands, Poland and Italy. Of children with CMA who were re-evaluated one year after diagnosis, 69% (22/32) tolerated cow's milk, including all children with non-IgE-associated CMA and 57% of those children with IgE-associated CMA.

CONCLUSIONS

This unique pan-European birth cohort study using the gold standard diagnostic procedure for food allergies confirmed challenge-proven CMA in <1% of children up to age 2. Affected infants without detectable specific antibodies to cow's milk were very likely to tolerate cow's milk one year after diagnosis, whereas only half of those with specific antibodies in serum 'outgrew' their disease so soon.

Piperacillin-induced DRESS: distinguishing features observed in a clinical and allergy study of 8 patients

BACKGROUND

DRESS (drug reaction with eosinophilia and systemic symptoms) syndrome is characterized by fever, rash, eosinophilia, and multiorgan failure. Previous reports have described differences in clinical and laboratory findings of DRESS syndrome depending on the inducing drug. Piperacillin has been reported as the drug responsible for this syndrome in 3 patients.

OBJECTIVE

To analyze and describe the clinical, laboratory, and allergy study findings of piperacillin-induced DRESS.

PATIENTS AND METHODS

Retrospective case series of patients diagnosed with DRESS associated with piperacillin-tazobactam (Pip/Taz) according to the Kardaun diagnostic score criteria. Assessment of causality was established using the Spanish Pharmacovigilance System and the lymphocyte transformation test (LTT). The allergy study included skin and epicutaneous tests.

RESULTS

Eight patients were diagnosed with DRESS due to Pip/Taz (3 probable and 5 definite cases). Skin rash was observed in all cases and facial edema in 50%; the mean latency period was 18 days. Fever was present in 7 patients. Liver and kidney injuries were detected in 6 and 3 patients, respectively. All patients had eosinophilia and a full recovery. The LTT to Pip/Taz was strongly positive in all patients, with a stimulation index of over 6. Three of 3 patients had a positive intradermal test to Pip/Taz, and 1 of 4 had a positive patch test. All patients had a negative LTT to carbapenems.

CONCLUSIONS

We have reported on the first case series of piperacillin-induced DRESS. A latency period of 18 days, skin rash, eosinophilia, fever, liver injury, and good prognosis were the most common features. The allergy study, and the LTT in particular, was highly useful for identifying Pip/Taz as the culprit drug and piperacillin as the responsible active ingredient.

The impact of double-blind placebo- controlled food challenge (DBPCFC) on the socioeconomic cost of food allergy in Europe

BACKGROUND

Double-blind placebo controlled food challenge (DBPCFC) is the gold standard diagnostic test in food allergy because it minimizes diagnostic bias.

OBJECTIVE

To investigate the potential effect of diagnosis on the socioeconomic costs of food allergy.

METHODS

A prospective longitudinal cost analysis study was conducted in Spain and Poland within the EuroPrevall project. Food-allergic patients were enrolled into the study and in all cases diagnosis was confirmed through a standardized DBPCFC. Data were collected through a self-administered survey on all aspects of health and social care resource use, costs of living, and costs of leisure activities. Costs were measured before and 6 months after the DBPCFC and reported in international dollars with 2007 as the benchmark year.

RESULTS

Forty-two patients were enrolled. Twenty-one patients had a negative DBPCFC and the suspected food was reintroduced into their diet. Comparing total direct costs before and after the DBPCFC, the reactive group spent a significantly higher amount (median increase of $813.1 over baseline), while the tolerant group's spending decreased by a median of $87.3 (P = .031). The amount of money spent on food 6 months after diagnosis was also significantly higher in the reactive group (P = .040). Finally, a larger, but not statistically significant, decrease in total indirect costs was observed in the tolerant group compared with the reactive group ($538.3 vs $32.3).

CONCLUSION

DBPCFC has an impact on indirect and direct costs of living. The main contribution to this increase was money spent on food.

Proton pump inhibitors are associated with hypersensitivity reactions to drugs in hospitalized patients: a nested case-control in a retrospective cohort study

BACKGROUND

Previous research has shown that gastric acid suppression by antacid drugs can promote allergic reactions to acid-labile food proteins. No data are available about whether antacid drugs can promote drug hypersensitivity reactions. The most potent and longer lasting inhibition of gastric secretion is provided by proton pump inhibitors (PPIs). We hypothesized that gastric acid suppression by proton pump inhibitors could be causative of drug hypersensitivity reactions during hospitalization.

OBJECTIVE

To estimate the risk of developing drug hypersensitivity reactions during the hospitalization of patients treated with proton pump inhibitors, and other associated factors.

METHODS

A nested case-control in a retrospective cohort study of hospitalized patients from September 2008 to December 2010 (70 771 admissions) was conducted using the registry of cases of interconsultations to the Allergy Department (161 confirmed cases of drug hypersensitivity reactions). A total of 318 controls were matched by first drug suspected in the hypersensitivity reaction, time of admission, age, gender and hospitalization wards.

RESULTS

The relative risk of drug hypersensitivity reaction occurrence during hospitalization of patients treated with PPIs compared with those not treated in the period of study was significant (RR: 3.97; 95% CI: 1.97-8.29). After controlling for confounders in the nested case-control cohort, the use of PPIs persists as a predisposing factor (OR: 4.35; 95% CI: 2-9.45). Personal history of drug allergy and a long hospitalization time were other predisposing factors of drug hypersensitivity reactions (DHRs). The hazard that a DHR has occurred during PPI treatment was 3.7% per day. The hazard for immediate or accelerated reactions was 1.706 (P = 0.003) times that of delayed reactions.

CONCLUSION AND CLINICAL RELEVANCE

In hospitalized patients, the use of proton pump inhibitors was associated with a significant increase risk of drug hypersensitivity reactions along with a personal history of drug allergies and long hospitalization time.

Expression of α-defensin 1-3 in T cells from severe cutaneous drug-induced hypersensitivity reactions

BACKGROUND

Cytotoxic T cells seem to be the main effector cells in Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). However, recent data support a role of the innate immune system in the etiopathology of drug-induced cutaneous reactions. In this study, we analyzed the expression of α-defensins 1-3 in mononuclear cells from patients with SJS/TEN, drug-induced maculopapular exanthema (MPE), and healthy donors.

METHODS

DEFA1A3 gene expression was analyzed by quantitative and end-point RT-PCR. Intracellular flow cytometry, immunofluorescence and immunohistochemistry were carried out to verify α-defensin 1-3 protein expression in mononuclear cells from peripheral blood and skin infiltrates. α-Defensin 1-3 concentration was evaluated in plasma and blister fluid samples by ELISA.

RESULTS

We herein describe DEFA1A3 gene expression in peripheral blood mononuclear cells (PBMCs) from patients with drug-induced cutaneous diseases. Gene expression analysis unveiled transcription in CD4 and CD8 peripheral blood T cells. Protein expression was confirmed by intracellular flow cytometry in mononuclear cells from the patients, including monocytes, NK cells, and T cells from peripheral blood and blister fluid. Further analysis of protein content by flow cytometry revealed higher protein levels in CD56(+) CD3(+) lymphocytes from patients with SJS/TEN when compared to MPE and healthy donors. Immunohistological analysis was used to confirm expression in dermal infiltrates. α-Defensin levels were estimated by ELISA to be 3- to 175-fold higher in blister fluid when compared to simultaneously drawn plasma samples.

CONCLUSION

Upregulation of innate immune molecules such as α-defensins 1-3 in T cells from patients with SJS/TEN may be involved in the etiopathology of these life-threatening diseases induced by medications.

The effect of a partially hydrolysed formula based on rice protein in the treatment of infants with cow's milk protein allergy

Infants diagnosed with allergy to cow's milk protein (CMP) are fed extensively hydrolysed cow's milk formulas, modified soy formulas or even amino acid-based formulas. Hydrolysed rice protein infant formulas have become available and have been shown to be well tolerated by these infants. A prospective open, randomized clinical study to compare the clinical tolerance of a new hydrolysed rice protein formula (HRPF) with an extensively hydrolysed CMP formula (EHF) in the feeding of infants with IgE-mediated cow's milk allergy. Ninety-two infants (46 boys and 46 girls, mean age 4.3 months, range 1.1-10.1 months) diagnosed with IgE-mediated cow's milk allergy were enrolled in the study. Clinical tolerance to the formula products was tested. Clinical evaluation included skin prick tests with whole cow's milk, soya and rice as well as antigens of CMP (beta-lactoglobulin, alpha-lactalbumin, casein and bovine seroalbumin), HRPF and EHF and specific IgE determinations to CMP using CAP technology. Patients were randomized to receive either an EHF based on CMP or a new HRPF. Follow-up was at 3, 6, 12, 18 and 24 months. Growth parameters were measured at each visit. One infant showed immediate allergic reaction to EHF, but no reaction was shown by any infant in the HRPF group. The number of infants who did not become tolerant to CMP during the study was not statistically different between the two groups. Measurement of IgE levels of infants allergic to CMP during the study showed no significant differences between the two formula groups. Growth parameters were in the normal range and similar between groups. In this study, the HRPF was well tolerated by infants with moderate to severe symptoms of IgE-mediated CMP allergy. Children receiving this formula showed similar growth and development of clinical tolerance to those receiving an EHF. In accordance with current guidelines, this HRPF was tolerated by more than 90% of children with CMP allergy and therefore could provide an adequate and safe alternative to CMP-hydrolysed formulas for these infants.

Detection, isolation and complete amino acid sequence of an aeroallergenic protein from rapeseed flour

BACKGROUND

Seed proteins have been found to cause hypersensitivity by ingestion or inhalation. Rapeseed flour was responsible for allergic symptoms in a patient, who develops into allergy to mustard spice.

OBJECTIVE

To determine the presence of allergenic proteins in rapeseed flour, and analyse the structure of the main component and its crossreactivity with the mustard allergen.

METHODS

SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and subsequent immunoblotting with a serum from a rapeseed allergic patient were performed to detect IgE-binding proteins. Proteolytic digestions and high performance liquid chromatography were used to obtain the peptides from the allergenic BnIII napin from rapeseed flour. Automatic Edman degradations were carried out to determine their amino acid sequences, which were compared with other sequences in nucleotide and amino acid sequence databases. Crossreactivity assays were carried out by ELISA inhibition using sera from a rapeseed allergic patient and from patients allergic to mustard.

RESULTS

The 2S albumins of rapeseed were recognized by the serum from a patient allergic to this seed. The most abundant isoform of the allergenic napins, BnIII, was used for structural and immunological analysis. The protein consists of two different chains of 9.5 and 4.5 kDa. Their complete amino acid sequences were determined. The protein exhibited structural relationships with other napin-like storage proteins from seeds. IgE and IgG crossreactivity between rapeseed and mustard allergens was also demonstrated. Considering the structural and immunological data, certain polypeptide regions are suggested to be involved in the allergenicity of these proteins.

CONCLUSIONS

Rapeseed contains 2S storage proteins which may cause allergy in hypersensitive individuals. These proteins exhibit great sequence similarity with 2S albumins from different seeds. Crossreactivity between mustard and rapeseed flours can be explained by sequence homology.

Allergy to pistachio: crossreactivity between pistachio nut and other Anacardiaceae

BACKGROUND

Anaphylaxis against Anacardiaceae nuts is uncommon and the allergens involved still poorly characterized. For this reason two patients with allergy towards pistachio nut (a member of the Anacardiaceae family) have been studied.

OBJECTIVE

Identification of immunoallergens present in pistachio nut and analysis of crossreactive antigens in other members of the same plant family, specifically cashew and mango.

METHODS

Presence of specific IgE for pistachio and cashew nut and for mango seed and pulp was determined by skin tests and radioallergosorbent assay (RAST). The allergenic profile of pistachio and cashew was analyzed by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE) followed by immunoblotting. Crossreactivity between pistachio and the other Anacardiaceae was studied by RAST inhibition.

RESULTS

Skin tests were positive for pistachio and cashew in the two children and for mango seed in one. RAST was positive for pistachio and cashew in both patients. On immunoblotting, serum from both patients recognized several pistachio and cashew allergens with a molecular weight ranging from < 14.2-70 kDa. RAST inhibition demonstrated common antigenic determinants between pistachio and cashew nut. Crossreactivity was also found between pistachio nut and mango seed but not with mango pulp.

CONCLUSION

Pistachio nut contains several protein allergens able to trigger type I hypersensitivity reactions. These allergens can be found also in cashew nut and mango seed but not in mango pulp.

Analysis of cross-reactivity between sunflower pollen and other pollens of the Compositae family

The sera of 20 patients with Compositae pollen allergy were investigated for the presence of IgE antibodies reacting against sunflower pollen by means of RAST and immunoblotting studies. Thirteen IgE-binding bands were detected with molecular weights ranging from 14.4 to 94 kd. Two of these bands, with molecular weights of 24 and 25 kd, contained major allergens that reacted strongly with 100% (24 kd) and 95% (25 kd) of the sera, respectively. Cross-reactivity between sunflower and other Compositae pollens (mugwort, marguerite, dandelion, golden rod, and short ragweed) was revealed by RAST and immunoblotting inhibition experiments. Mugwort pollen exhibited the greatest degree of allergenic homology (cross-reactivity) with sunflower pollen, whereas at the other end of the spectrum, short ragweed showed less cross-reactive epitopes.

Possible consequences of elimination diets in asymptomatic immediate hypersensitivity to fish

The natural history of IgE antibodies to food without related symptoms is unknown. We have followed the progress of 7 children with various atopic diseases and asymptomatic immediate hypersensitivity to fish, treated with elimination diet in spite of full alimentary tolerance. During the diet period, between 24 and 113 months, all 7 patients presented immediate symptoms upon accidental exposure to or challenge tests with fish (skin symptoms in all 7 cases, digestive in 5, respiratory in 4, and anaphylaxis in 2), which differed from those related to atopic diseases previously present. The levels of fish-specific IgE (prick test, RAST) remained unchanged or were increased. These findings suggest that during elimination diet, and perhaps due to minimal and hidden contact with the allergen, the patients' degree of sensitization may increase, turning an asymptomatic into a symptomatic immediate hypersensitivity.

A possible consequence of long-term elimination diet in IgE mediated subclinical food hypersensitivity

IgE-mediated sub-clinical food hypersensitivity is recognized, but the hypersensitivity indicated is not always in accord with the observed symptoms. Study of 2 cases shows the inefficacy of a prescribed exclusion diet, without confirmation of the relationship between symptomatology and the food allergy. In addition, elimination of the foods aggravated the sensitivity of the patients and symptoms after provocation tests. Further studies must be made to decide whether there is a sound basis for long-term exclusion diets in sub-clinical food hypersensitivity.