Elevated levels of leukotriene C4 synthase mRNA distinguish a subpopulation of eosinophilic oesophagitis patients.

BACKGROUND: Cysteinyl leukotrienes contribute to Th2-type inflammatory immune responses. Their levels in oesophageal tissue, however, do not distinguish patients with eosinophilic oesophagitis (EoE) from controls. OBJECTIVE: We asked whether mRNA levels of leukotriene C4 synthase (LTC4 S), a key regulator of leukotriene production, could serve as a marker for EoE. METHODS: Digital mRNA expression profiling (nCounter(®) Technology) was performed on proximal and distal oesophageal biopsies of 30 paediatric EoE patients and 40 non-EoE controls. Expression data were confirmed with RT-qPCR. LTC4 S mRNA levels were quantified in whole blood samples. Leukotriene E4 was measured in urine. RESULTS: LTC4 S mRNA levels were elevated in proximal (2.6-fold, P < 0.001) and distal (2.9-fold, P < 0.001) oesophageal biopsies from EoE patients. Importantly, increased LTC4 S mRNA transcripts identified a subpopulation of EoE patients (28%). This patient subgroup had higher serum IgE levels (669 U/mL vs. 106 U/mL, P = 0.01), higher mRNA transcript numbers of thymic stromal lymphopoietin (TSLP) (1.6-fold, P = 0.009) and CD4 (1.4-fold, P = 0.04) but lower IL-23 mRNA levels (0.5-fold, P = 0.04). In contrast, elevated levels of IL-23 mRNA were found in oesophageal biopsies of patients with reflux oesophagitis. LTC4 S mRNA transcripts in whole blood and urinary excretion of leukotriene E4 were similar in EoE patient subgroups and non-EoE patients. CONCLUSION & CLINICAL RELEVANCE: Elevated oesophageal expression of LTC4 S mRNA is found in a subgroup of EoE patients, concomitant with higher serum IgE levels and an oesophageal transcriptome indicative of a more-pronounced allergic phenotype. Together with TSLP and IL-23 mRNA levels, oesophageal LTC4 S mRNA may facilitate diagnosis of an EoE subpopulation for personalized therapy.

Allergic sensitization in kidney-transplanted patients prevails under tacrolimus treatment.

BACKGROUND: Type I allergies have repeatedly been reported after solid organ transplantation despite T cell-targeted immunosuppressive therapy. A causal relationship with tacrolimus has been proposed. OBJECTIVE: The present study directly compared the occurrence of allergic sensitization and disease under tacrolimus- vs. cyclosporin A-based immunosuppressive therapy. METHODS: The prevalences of IgE-mediated sensitization and allergy were assessed in a cross-sectional study of kidney-transplanted adults receiving tacrolimus (n = 100) or cyclosporin A (n = 100). METHODS: included a standardized questionnaire, skin prick test and measurement of total and specific IgE against common nutritive and inhalant allergens. Results The prevalence of sensitization was significantly higher in the tacrolimus- than in the cyclosporin A-treated group (34%, n = 34, vs. 20%, n = 20; P = 0.026). The rate of clinically relevant allergy in patients receiving tacrolimus was twice that in patients receiving cyclosporin A (15%, n = 15, vs. 8%, n = 8; P = 0.12). No other factor (age, serum drug level, concomitant immunosuppressive medication, time since transplantation, underlying disease) was found to have an influence on sensitization or allergy prevalence (logistic regression). CONCLUSION AND CLINICAL RELEVANCE: Our results suggest that post-transplant immunosuppression with tacrolimus is associated with an increased occurrence of IgE-mediated sensitization and probably manifestation of allergic disease, which has to be treated specifically despite immunosuppressive therapy.

Impact of systemic immuno-suppression after solid organ transplantation on allergen-specific responses.

INTRODUCTION: The immunosuppressive therapy in solid organ transplantation targets mainly the T- and B-cell-mediated immune response. However, there is evidence that it neither suppresses sensitization nor clinical manifestation of allergic diseases in organ-transplanted patients. OBJECTIVE: This study addresses the question whether allergen-specific responses are altered by systemic immunosuppression via negative effects on the T-regulatory cell compartment and a more pronounced suppression on Th1-type T-cell responses. MATERIAL AND METHODS: Peripheral blood mononuclear cells from 65 solid organ-transplanted (kidney, liver, lung) children, adolescents, and young adults and 18 healthy, matched controls were included, and their clinical and sensitization status assessed. Allergen-specific proliferation, intracellular cytokine production, frequency of forkhead box P3 (FOXP3)+ CD3+ CD4+ CD25(high) cells, mRNA expression of IL-10, transforming growth factor (TGF)-ß and FOXP3 (real-time RT-PCR) of peripheral blood mononuclear cells or bronchoalveolar lavage fluid (BAL)-derived cells, and the inhibitory capacity of T-reg cells were investigated. RESULTS: Immunosuppression led to a significantly altered regulatory marker profile expressed by enhanced TGF-ß mRNA production and a reduced frequency of FOXP3+ CD4+ CD3+ cells in solid organ transplanted individuals. FOXP3 expression in BAL cells of lung-transplanted patients was significantly decreased. Allergen-specific proliferation was not significantly altered despite long-term immunosuppression. However, suppression of allergen-specific responses via the T-regulatory cell fraction was deficient in immunosuppressed individuals. CONCLUSION: The results suggest an insufficient control of allergen-specific responses via the Treg-cell compartment under systemic immunosuppression.

First evidence of a possible association between gastric acid suppression during pregnancy and childhood asthma: a population-based register study.

BACKGROUND: Recent data in mice suggest that acid suppression during pregnancy yields offspring with type 2 T helper-dominant immunity, suggesting a predisposition for allergy. OBJECTIVE: To determine the association of in utero exposure to acid-suppressive medications and the subsequent development of allergic diseases in children. METHODS: We studied a population-based observational cohort formed by linking data from three Swedish national healthcare registers: the Medical Birth Register, the Hospital Discharge Register, and the Swedish Prescribed Drug Register. Main outcome measures included a hospital discharge diagnosis of an allergic disease or prescription for asthma medications, epinephrine auto-injectors, antihistamines or steroid ointments in children. Data were analysed using the Mantel-Haenszel procedure. RESULTS: Twenty-nine thousand four hundred and ninety (5.03%) children had a discharge diagnosis of allergy or prescriptions for allergy medications. Five thousand six hundred and forty-five (0.96%) children had been exposed to acid suppression therapy during pregnancy; of these, 405 (0.07%) were treated for allergic diseases. Exposure to acid-suppressive medications in utero was associated with an increased odds ratio (OR) for developing allergy (OR 1.43, 95% confidence interval (95% CI) 1.29-1.59). We observed this association irrespective of the type of drug, time of exposure during pregnancy, and maternal history of allergy. The use of maternal acid-suppressive medication was associated with an increased OR for the development of childhood asthma (3.7% in the population at large vs. 5.6% in exposed children, OR 1.51, 95% CI 1.35-1.69), but not for other allergic diseases. CONCLUSION: These data provide first evidence of a significant association between in utero exposure to acid-suppressive drugs and the risk of developing childhood asthma.

Allergen specific responses in cord and adult blood are differentially modulated in the presence of endotoxins.

BACKGROUND: Endotoxins are common contaminants in allergen preparations and affect antigen-specific cellular responses. Distinct effects of endotoxin on cells in human umbilical cord and adult blood are poorly defined. OBJECTIVES: To examine the effect of endotoxins in allergen preparations on cellular responses in human cord and peripheral blood (PB). METHODS: The endotoxin content in beta lactoglobulin (BLG), the peanut allergen Ara h 1 and the major birch pollen allergen Bet v 1 was assessed. Proliferation and cytokine response of mononuclear cells towards contaminated and lipopolysaccharide (LPS)-free allergens were evaluated at different time-points. Fractions of contaminated BLG were generated and assayed on their immuno-stimulatory capacity. The involvement of toll-like receptor (TLR) 2 and 4 was investigated by blocking antibodies and TLR-transfected human embryonic kidney cells. RESULTS: The proliferative response of cord blood (CB)-derived mononuclear cells towards allergen-preparations at day 3 was related to the level of LPS contamination. At day 7, proliferation was also detected in the absence of endotoxin. Cytokine production in CB was strongly affected by the content of endotoxin, TLR-4 dependent and not related to the allergen content. Allergen- and endotoxin-induced proliferative responses were generally significantly higher in CB than in adult blood. CONCLUSION: Endotoxins in allergen preparations confound allergen-specific cellular responses. The impact of these contaminations varies with the blood source (CB vs. PB), the type of allergen and is time- and dose-dependent.

[Cow's milk allergy: guidelines for the diagnostic evaluation]. / Verdacht auf Kuhmilchallergie: Praktische Empfehlungen zum diagnostischen Vorgehen.

About 2% of the general population and up to 6% of children suffer from food allergy. Cow's milk is charged with a important role in infancy after weaning, since conventional formula are based on its procession. IgE-mediated and Non-IgE- mediated allergic reactions, which are different in manifestation and pathogenesis, can be distinguished. A special role play the exacerbation of atopic dermatitis and the gastrointestinal-food-hypersensitivity-reactions. Skin-prick-test and determination of specific IgE are important diagnostic tools beside medical history. The golden standard of diagnosis is the double-blind-placebo-controlled-food- challenge. The clear result from food-challenge allows to verify suspected food allergies or, on the other hand, to avoid unnecessary diets. Extensively-hydrolysed-formula or Amino-acidformula are a high nutritional value alternative in case of proved cow's milk allergy in infancy.

Early exposure to latex products mediates latex sensitization in spina bifida but not in other diseases with comparable latex exposure rates.

BACKGROUND: The high prevalence of latex sensitization in patients with spina bifida (SB) has been attributed to repeated and early exposure to latex products. Other diseases such as gastroschisis/omphalocoele and post-haemorrhagic/congenital hydrocephalus are also associated with repeated and early latex exposure. OBJECTIVE: The aim of the study was to evaluate whether the high prevalence of latex sensitization in patients with SB is rather related to the underlying disease itself than to disease-associated known risk factors. METHODS: We compared children with SB (n=35), children with gastroschisis/omphalocoele (G/O, n=20) and children with post-haemorrhagic/congenital hydrocephalus (PH, n=45). All children with SB and PH had a ventriculo-peritoneal shunt since a very young age. Patients who underwent three or less surgical procedures matched in terms of age, number of operations, atopy and gender distribution, and were analysed for IgE sensitization rates to latex. RESULTS: In the SB group, 16 of 35 patients (46%) showed elevated latex-specific IgE antibodies in contrast to one of 20 patients (5%) in the G/O group and four of 45 patients (8.9%) in the PH group (P<0.0005 and P<0.005, Fisher's exact test). Comparing matched control groups (

Gastro-duodenal digestion products of the major peanut allergen Ara h 1 retain an allergenic potential.

BACKGROUND: The process of gastro-duodenal digestion may play a role in determining the allergenic properties of food proteins. The sensitizing and allergenic potential of digestion products of highly degraded allergens, such as the major peanut allergen Ara h 1, is currently under debate. We evaluated the effect of in vitro gastro-duodenal digestion of Ara h 1 on T cell reactivity and basophil histamine release. METHODS: An in vitro model of gastro-duodenal digestion was used to investigate changes in the allergenic properties of Ara h 1 using in vitro assays monitoring T cell reactivity (proliferation, cytokine production) and histamine release of basophils from peanut allergic individuals. The digestion process was monitored using an SDS-PAGE gel. RESULTS: In vitro gastric digestion led to rapid degradation of Ara h 1 into small fragments M(r) L5600. Gastric digestion did not affect the ability of Ara h 1 to stimulate cellular proliferation. Gastro-duodenal digestion significantly reduced its ability to stimulate clonal expansion (P<0,05; Wilxocon's signed rank test). The Th-2 type cytokine polarization of T cells from peanut allergic donors (IFN-gamma/IL-13 ratio and IFN-gamma/IL-4 ratio of CFSE(low) CD4(+) T cells) remained unchanged regardless of the level of digestion. Histamine release of basophils from peanut allergic individuals was induced to the same extent by native Ara h 1 and its digestion products. CONCLUSION: Gastro-duodenal digestion fragments of Ara h 1 retain T cell stimulatory and IgE-binding and cross-linking properties of the intact protein.

Most of diaplacentally transferred allergen is retained in the placenta.

BACKGROUND: Transplacental transfer of nutritive and inhalant allergens has been described being potentially responsible for a series of events leading to antigen-specific immune responses in the fetus. As such, cord blood T cell responses appear ubiquitously. However, studies failed to reveal a consistent dose-response relationship between antenatal allergen exposure and allergen-specific cellular reactivity in cord blood. OBJECTIVE: To examine the transfer process of allergens (ovalbumin (OVA), beta-lactoglobulin (BLG), birch pollen allergen Bet v1) in placental tissue (BeWo cell line, ex vivo placenta model). METHODS: The choriocarcinoma cell line BeWo was used to study the allergen uptake and transfer experiments in vitro. In the ex vivo placenta model the contribution of different placental compartments was evaluated. For this, immuno-histochemistry, immuno-electronmicroscopy and ELISA techniques were applied using monoclonal antibodies to Bet v1, OVA and -BLG. RESULTS: In vitro transfer studies on a BeWo cell-layer revealed an intracellular allergen uptake and a trans-trophoblastic allergen transfer, which was temperature- and concentration dependent, pH sensitive and asymmetric. Allergen-specific staining of placental tissue after allergen perfusion (BLG) demonstrated bulk of the allergen in the syncytio-trophoblastic cell layer and minor staining in the villous stroma and in the endothelium of fetal vessels. Immunogold staining revealed an accumulation of the perfused allergen in the trophoblastic basement membrane. CONCLUSION: In vitro/ex vivo trans-trophoblastic and trans-placental allergen transfer is shown with an accumulation of most of the allergen in placental tissues, potentially explaining the missing direct dose-response relationship between prenatal (maternal) allergen exposure and allergen-specific cellular reactivity in cord blood.

Absence of systemic immunologic changes during dose build-up phase and early maintenance period in effective specific sublingual immunotherapy in children.

BACKGROUND: Sublingual immunotherapy (SLIT) has been reported to be a safe treatment for inhalant allergies in children. Yet the immunologic mechanisms resulting in clinical improvement are poorly understood. OBJECTIVE: To identify early systemic immunologic changes during the first 8 weeks of clinically effective SLIT to grass pollen, tree pollen or house dust mite in paediatric patients with allergic rhinoconjunctivitis and/or asthma. METHODS: Peripheral blood mononuclear cells and plasma samples of 13 children with reduced symptoms after 1 year of SLIT were obtained before therapy and at 2 and 8 weeks after the initiation of SLIT. Allergen-specific lymphocyte proliferation assays were performed, and allergen-induced cytokine production (IL-2, IL-4, IL-10, IFN-gamma, and TGF-beta(1)) was measured by ELISA and flow cytometry. Allergen-specific IgE, IgG1, IgG4, and IgA levels in plasma samples were determined in ELISA. RESULTS: During the first 8 weeks of successful SLIT, allergen-specific lymphoproliferation (n=13) as well as levels of allergen-specific intracellular (n=8) and secreted cytokines (n=9) did not change significantly. In addition, no alterations in levels of allergen-specific Igs (n=7) were observed. CONCLUSION: We could not find any early systemic immunologic changes during the first 8 weeks of clinically effective SLIT to inhalant allergens in paediatric patients with allergic rhinoconjunctivitis and/or asthma.

Increased prevalence of latex-sensitization among children with chronic renal failure.

BACKGROUND: Type-I-allergy to natural rubber latex (NRL) has been shown to be more prevalent among certain groups of patients. Children suffering from chronic renal failure (CRF) could be a suspected risk group because of their intense exposure to latex through catheters, gloves and anesthetic equipment during frequent hospitalizations from early life on. We investigated the prevalence of latex-sensitization among this group of patients and sought to identify risk factors. METHODS: Ninety-three patients (mean age 10.5 years) suffering from CRF were assessed by questionnaire-based history (details on renal disease, number and kind of surgical procedures, family and personal history of atopic diseases, allergic reactions to NRL, and the use of pacifiers) and by measurement of total and latex-specific serum immunoglobulin (Ig)E. RESULTS: Ten of 93 (10.8%) patients showed elevated latex-specific IgE-levels. One of 10 patients reported clinical symptoms to latex-allergen, but no allergic reactions to NRL during medical care were reported. Sensitized patients were significantly more likely to be atopic, reflected by a positive history of other allergies as well as elevated total serum IgE-levels, and had a significantly higher number of urogenital surgeries (P = 0.02 in all cases, Fisher's exact and Wilcoxon test, respectively). CONCLUSION: This study demonstrates that children with CRF are at increased risk of latex-hypersensitivity. Significant associations with atopy and repeated surgeries were observed. Larger studies are required to elucidate whether these children are also at increased risk of anaphylaxis and therefore deserve preventive measures.