New-onset post-transplantation food allergy in children--is it attributable only to the immunosuppressive protocol?

Atopy and allergy following solid organ transplantation: A 15-year experience

AIM

There are increasing reports of atopy/allergy following solid organ transplantation, especially paediatric liver transplantation (LT) with minimal New Zealand (NZ) data. We describe the prevalence of transplant-acquired atopy and allergy (TAA) in NZ paediatric liver transplant recipients, compared to paediatric kidney and adult liver transplants.

METHODS

TAA focussed health questionnaires were sent to patients selected from the NZ transplant registry (transplanted between January 2003 and December 2017). Demographic and clinical data were also obtained from electronic health records and follow-up phone calls.

RESULTS

A total of 232 patients (62% male) participated (111 adult liver, 82 paediatric liver, 39 paediatric kidney transplant recipients). Tacrolimus was primary immunosuppression for all LT patients; with combined tacrolimus, mycophenolate and corticosteroids for kidney transplants. The number of patients who developed TAA was significantly higher (P < 0.001) in the paediatric LT group (36/82, 44%) compared to adult liver (12/111, 11%) and paediatric kidney transplants (4/39, 10%). Eczema was most common (73%), then IgE-mediated food allergy (FA, 33%), allergic rhinitis (19%) and asthma (17%). Six paediatric LT recipients developed eosinophilic oesophagitis (EoE). Egg was the most common allergen in the IgE-mediated FA group. TAAs were severe enough to warrant a switch from tacrolimus to another agent in seven paediatric LT patients. For paediatric LT patients, female gender and younger age at transplant were risk factors for developing TAA.

CONCLUSIONS

TAA is common in paediatric liver transplant recipients, with female gender and younger age at transplant being risk factors identified. This highlights the need for detailed atopic and allergy history to be incorporated in all pre-transplant assessments.

De Novo Multiple Food Allergy After Liver Transplantation: A Case Report

Food allergy is defined as an immune-mediated response to food. Food allergy after solid organ transplantation was first described in 1997 after liver and kidney transplantation. A three years- five-month-old male was admitted with swelling of the lip after food intake. He had received a liver transplant from a living donor at ten months of age due to biliary atresia. Treatment with tacrolimus and mycophenolate mofetil was monitored, and he was admitted to the emergency department with complaints of swelling of the lip that developed immediately after eating eggs in our department at 20 months of age. No associated respiratory, skin, or gastrointestinal findings were observed in the case, who had previously consumed eggs without problems. Later, after consuming honey and tahini mixture, corn with mayonnaise sauce at different times, swelling developed on his lips and eyes. According to tests, egg, peanut, and hazelnut were excluded from the patient's diet. The case was followed up with diet therapy for two years without any problems. Organ donors should be screened for food allergies to predict the risk of organ recipients for new food allergies after transplantation. Although there is no evidence of food allergies in the donor, it should be kept in mind that new food allergy may develop in patients who have undergone solid organ transplantation, and patients should be followed up in this regard.

Mycophenolate mofetil use is associated with reduced incidence of food allergy in liver transplanted children

OBJECTIVES

The incidence of food allergy in children following liver transplantation is high and the pathogenesis is still not known. We aimed to identify risk factors for development of food allergies in liver transplant children.

METHODS

107 children and adolescents who underwent liver transplantation from 1999 to 2019 were included. Data were retrospectively collected from medical records included total and specific IgE, eosinophil cationic protein and eosinophil count 12 months after transplantation and at yearly follow up (median follow-up).

RESULTS

24/107 (22%) patients reported clinical food reactions. Median time from transplantation to debut of food allergy was 1.6 (IQR 0.6-3.3) years. Mycophenolate mofetil (MMF) was discontinued in 24/78 patients (31%) due to side effects. Children treated with MMF in addition to tacrolimus one year after transplantation reported less food allergy (12.5% vs. 37.8%, p=0.003) and sensitization to food allergens one year after transplantation (8.9% vs. 17.8%, p=0.02) than those not receiving MMF. Tacrolimus trough levels did not differ between the patients treated with MMF and those who were not. Treatment with MMF two years after transplantation was associated with less food allergy (p=0.001) and food sensitization (p=0.002), also when adjusted for age at transplantation (p=0.006 and p=0.03, respectively) or for use of basilixmab (p=0.015 and p=0.018, respectively). Basiliximab was also associated with less food allergy.

CONCLUSIONS

Use of MMF one and two years after transplantation was associated with less food allergy and sensitization against food allergens. The effect of MMF was not due to reduced trough levels of of tacrolimus. An infographic is available for this article at: https://links.lww.com/MPG/C821.

De novo Food Allergy After Pediatric Liver Transplantation: A Systematic Review

Background

Liver transplant (LT) recipients, particularly children, have an increased risk of developing de novo food allergies (FAs) after transplantation both compared to all the other transplant groups and to the general population. Little is known about the pathogenesis underlying this phenomenon and comprehensive recommendations or clinical practice guidelines are still lacking, mainly due to the scarcity of high-quality evidence.

Aim

We aimed to prepare a systematic review on de novo FA in pediatric LT recipients to assess epidemiology and risk factors, evaluate the correlation to specific food groups, describe clinical manifestations, investigate the rate of tolerance acquisition over time and report available therapeutic strategies.

Methods

We conducted this systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). MEDLINE, Scopus, Web of Science, Wiley online library, Cochrane Library, and ClinicalTrials.gov databases were systematically searched for studies published from January 1980 to September 2021. All the articles were checked independently by two reviewers in two steps. A total of 323 articles were screened, and 40 were included for data extraction.

Results and Conclusions

We found that de novo FAs develop in the 15% of pediatric LT recipients, especially in the first 2 years after surgery, with higher risk related to younger age at transplantation (especially <2 years of age) and tacrolimus immunosuppression. Subjects are often allergic to multiple foods, and 15% of them suffer from anaphylaxis. The majority of patients do not spontaneously outgrow their symptoms during follow-up. The discontinuation of tacrolimus in favor of cyclosporine or the association of tacrolimus with mycophenolate have been associated with the resolution or the improvement of FA in small retrospective case series and could be considered in case of severe or multiple, difficult to manage FAs. Prospective multicenter studies are needed to confirm these findings, guide the risk-based stratification of pediatric LT recipients, and provide for high-evidence therapeutic strategies for children with de novo FA.

De Novo Food Allergy in Pediatric Recipients of Liver Transplant

ABSTRACT

Allergic and atopic conditions, including food allergy, asthma, eczema and eosinophilic disease of the gastrointestinal tract after liver transplant in previously non-allergic children have been increasingly described. After a liver transplant, children can present mild to severe reactions to food allergens (ie, from urticaria-angioedema to life-threatening anaphylactic reactions). De novo post-transplant food allergy may become clinically evident in children who undergo liver transplant between a few months and a few years of transplant. The present narrative review aims to describe the spectrum of de novo post-transplant food allergy development, the current theories of pathogenesis, risk factors and to suggest possible clinical management strategies.

Post-transplant food anaphylaxis in an adult cord blood transplant recipient (Ms. No. IJHM-D-20-01037R1)

Transplant acquired food allergy (TAFA) is a well-known complication following pediatric liver transplantation, but post-cord blood transplantation (post-CBT) TAFA has rarely been reported. Here, we describe a case of new-onset food anaphylaxis after CBT in an adult patient that demonstrates that post-CBT allergen-challenge is not a risk for long-term allergic sensitization even in adult recipients. The patient was a 39-year-old Japanese man with aggressive NK cell leukemia. He had no previous history of allergies. After receiving CBT, the patient had an unbalanced diet with high preference for bread, bananas, miso-soup, cow's milk, cheese, egg, sesame and buckwheat soba noodles, and experienced repeated diarrhea. Six months later, he developed symptoms such as vomiting, epigastric pain, diarrhea, high fever and hypotension. The condition was initially diagnosed as enterocolitis, but symptoms recurred after consumption of buckwheat. Anaphylaxis induced by buckwheat was confirmed with serum radioallergosorbent tests (RAST), showing allergen-specific IgE for buckwheat (greater than 100 U/mL, Class 6) and egg ovomucoid (Class 4). Nineteen months after a buckwheat and egg-free diet, serum RAST for buckwheat and egg significantly improved. As a result, the patient acquired a tolerance and was able to consume buckwheat and egg without allergic symptoms.

Conversion from tacrolimus to sirolimus as a treatment modality in de novo allergies and immune-mediated disorders in pediatric liver transplant recipients

De novo PTAID may develop in pediatric solid organ transplant recipients, have a diverse spectrum, and are occasionally treatment resistant. Previous reports showed resolution of immune cytopenias in solid organ transplant recipients following replacement of the calcineurin inhibitor tacrolimus with the mTOR inhibitor sirolimus. Herein we describe a retrospective review (2000-2017) of subjects who developed PTAID in whom immunosuppression was changed to sirolimus. Eight recipients (6 males) of either liver (n = 7) or multivisceral transplant (n = 1) suffered from severe, treatment-resistant PTAID and were switched from tacrolimus to sirolimus. The median age at transplant was 1 year (range 0.5-2.4 years). Six (75%) recipients developed de novo allergy and 2 immune-mediated diseases. The median age at presentation of PTAID was 2.7 (1.4-9) years at a median of 1.3 (0.25-8) years after transplantation. The median time from PTAID presentation to conversion to sirolimus was 1.8 (0.45-10) years. Complete resolution of symptoms was seen in 4 (50%) patients after a median of 12 (range 4-24) months including 2 patients with immune-mediated disease, 1 eczema, and 1 with eosinophilic colitis. One patient with multiple food allergies had a partial response and 3 (38%) had no response. None of the 8 recipients developed sirolimus-attributed adverse events or acute rejection during a median follow-up of 5 (0.6-8) years after the conversion. Immunosuppression conversion from tacrolimus to sirolimus can be an effective therapy in patients suffering severe or treatment-resistant PTAID, suggesting a potential role for tacrolimus in the pathogenesis of PTAID.

High Frequency of Concomitant Food Allergy Development and Autoantibody Formation in Children Who Have Undergone Liver Transplantation

BACKGROUND

Allergy and other immune-mediated diseases are more frequently reported in children who have undergone liver transplantation. Furthermore, autoantibodies are also prevalent, suggesting a state of immune dysregulation in these patients. Whether or not these processes occur simultaneously in the same individual has not been studied previously.

METHODS

A cohort of 43 children who had undergone liver transplantation for nonautoimmune liver disease at median age of 1.3 years was investigated for allergy and autoimmune disease. Sensitization to food and inhalant allergens was assessed, and autoantibodies were measured.

RESULTS

The prevalence of food allergy was 26% and that of respiratory allergy was 23%, whereas 33% and 26% of the subjects were sensitized to food and inhalant allergens, respectively. Autoimmune disease (ie, autoimmune hepatitis) occurred in a single individual (2%), whereas autoantibodies were present in 44% of the children. Food allergy and autoantibodies occurred concomitantly in 19% of the children, which was almost twice the frequency expected by chance (11%, P = 0.04). Respiratory allergy and the presence of autoantibodies were unrelated (12% concurrence versus the expected 10%, P = 0.73). In the logistic regression analysis, autoantibody formation was associated with discontinued immunosuppression and food allergy, with odds ratios of 13 (P = 0.01) and 7.1 (P = 0.03), respectively.

CONCLUSIONS

In contrast to respiratory allergy, food allergy and autoantibody formation occurred together in the same children who underwent liver transplantation at a frequency higher than would be expected by chance. This may reflect an underlying immune dysregulation that impairs immune tolerance to both food allergens and autoantigens.

Transfer of peanut allergy from donor to recipient after liver transplant

31 years old female with a history of contact dermatitis, eczema, allergic rhinitis, pernicious anemia, alopecia areata and latent tuberculosis was treated concurrently with methotrexate along with isoniazid and pyridoxine. Five months into the therapy she developed acute onset jaundice progressing into fulminant liver failure with altered mentation and worsening liver function tests. Extensive workup including serological and histopathological evaluation revealed drug-induced liver injury as the etiology of her liver failure and she underwent a successful orthotropic liver transplant. On post-transplant follow-up at four months, she was noted to have an allergic reaction consisting of a perioral rash and swelling (without anaphylaxis) after receiving a kiss from her significant other who had just eaten a peanut butter chocolate. She denied any history of allergic reaction to peanuts prior to the transplant. Percutaneous skin testing revealed immediate hypersensitivity to peanut, hazelnut, and pecan believed to be acquired newly post-transplant. Further investigation revealed that the organ donor had a documented history of systemic anaphylaxis from the peanut allergy and a positive peanut-specific IgE level. Also, another parallel solid organ recipient (lung transplant) from the same organ donor experienced a serious anaphylactic reaction after peanut exposure. This is a case of food (peanut) allergy transfer from the donor to the recipient after the liver transplant. This case highlights the importance of incorporating known donor allergies as a part of pre-transplant screening, given the potentially serious consequences from the transfer of allergies to a previously anergic recipient.

Cytokine profile in children with food allergy following liver transplantation

BACKGROUND

LTX in children is associated with increased risk of food allergy, and the mechanisms underlying this are unknown. We wanted to study whether plasma cytokine profile differed in liver transplanted children, with and without food allergy, and whether it differed from untransplanted children with CLD.

METHODS

Plasma cytokines, total and specific IgE in nine patients with food allergy were compared with 13 patients without food allergy following LTX, and also with seven untransplanted patients with CLD.

RESULTS

No difference was found in the cytokine profile between liver transplanted patients with and without food allergy. Transplanted patients with food allergy having received a prescription of epinephrine had a significantly higher total IgE (2033 [234-2831] vs 10 [5-41] IU/L, P = .002) and MIP-1b (52 [37-96] vs 36 [32-39], P = .035) compared with transplanted patients without food allergy. Two patients with severe food allergy responded favorably to conversion from tacrolimus-based immunosuppression to MMF and corticosteroids with reduction in clinical symptoms, total IgE, specific IgE, IL-1ra, IL-4, RANTES, PDGF, MIP-1a, and TNFα. The transplantation group had higher levels of IL-1b, IL-5, IL-7, IL-13, GCSF, IFNγ, and MIP-1a compared with the CLD group.

CONCLUSIONS

No overall difference was found in plasma cytokine profile between patients with and without food allergy. Patients with severe food allergy had significant elevation of MIP-1b. Discontinuation of tacrolimus reduced total and specific IgE and changed plasma cytokine profile. The plasma cytokine profile in liver transplanted children was different compared with children with CLD.

Asthma, Eczema, and Food Allergy in Children Following Liver Transplantation

OBJECTIVES

To describe the prevalence and the relationship between asthma, eczema, food allergy, and rhinitis in children after liver transplantation.

STUDY DESIGN

Children who were liver transplant recipients were investigated to assess whether the high prevalence of food allergies was accompanied by eczema, rhinitis, and asthma. Furthermore, we included 56 children with chronic liver disease to explore the risk of allergy, eczema, and asthma in this group.

RESULTS

After liver transplantation, children had higher prevalence of allergic reactions to food as compared with children with chronic liver disease (P < .001). Current asthma (P = .04) and eczema (P < .02) were observed more frequently in transplanted children as compared with children with chronic liver disease. For transplanted children who had ever received tacrolimus the relative risk (RR) of asthma was 1.7 (95% CI, 1.2-2.4; P = .02) as compared with children with chronic liver disease. Transplanted children with asthma had higher rates of sensitization to food allergens than those without asthma (RR, 3.6; 95% CI, 1.3-10.3; P = .01). The most frequent food allergens associated with asthma in transplanted children were milk (RR for asthma, 3.9; 95% CI, 1.6-9.4; P < .01), eggs (RR, 2.9; 95% CI, 1.2-7.0; P = .03), and peanuts (RR, 3.7; 95% CI, 1.6-8.3; P < .01). Food allergies occurred earlier than asthma, at 1.5 years after transplantation (IQR, 0.5-3.0 years) vs 2.5 years after transplantation (IQR, 1.0-4.5 years; P < .05). Food allergies were also associated with eczema, but not with sensitization to aero-allergens or rhinitis.

CONCLUSIONS

The high risk of food allergies in children who were liver transplant recipients was associated with eczema and asthma, but not rhinitis. The most frequent food allergens associated with asthma were milk, eggs, and peanuts.

Liver-associated immune abnormalities

In recent years, the cross talk between the liver and the immune system is being uncovered, in part by studying liver involvement in primary immune deficiencies (PID) and in part by investigating the alterations of the immune system following orthotopic liver transplantation (OLT). Here we review some of the reciprocal interactions between the liver and the immune system. Patients with PID, particularly those involving inherited defects in T and B cells or innate immunity are prone to infections and inflammatory responses that often involve the liver. Omenn's syndrome, familial hemophagocytic lymphohistiocytosis, AIRE, FOXP3 and CD25 deficiencies, common variable immunodeficiency, CD40 ligand deficiency, chronic granulomatous disease and autoimmune lymphoproliferative syndrome are some of the notable PID associated with typical hepatobiliary abnormalities. Knowledge gained from studying these PID together with laboratory and histological evaluations can assist in managing PID-associated liver dysfunction. The liver itself also has important effects on the immune system, as evident from the growing experience with patients surviving OLT. Up to 40% of pediatric patients who receive OLT suffer from post transplantation allergy, autoimmunity, and immune-mediated disorders (PTAA). PTAA is more common after liver and heart transplantations than kidney transplantations. Potential contributing factors for the increased frequency of PTAA after OLT include the age of the patients, the prolonged use of tacrolimus and the reduced regulatory immune function with a shift towards a TH2 immune response. Better understanding of the mechanisms leading to the development of PTAA after OLT will also improve the management of these conditions.

Increase of natural killer cells in children with liver transplantation-acquired food allergy

BACKGROUND

Transplantation-acquired food allergies (TAFA) are frequently reported and considered to be caused by immunosuppressive therapy. The aim of this study was to investigate the allergic and immunologic responses in children who had liver or kidney transplantations.

METHODS

Twelve children receiving liver transplantations and 10 children receiving kidney transplantations were investigated. All children underwent the allergy work-up and in most of them, lymphocyte screening and serum cytokine measurements were also performed.

RESULTS

TAFA were found in 7/12 (58%) children with liver transplantations and in none of the 10 children with kidney transplantations. The mean age at transplantation was significantly lower in children who underwent liver transplantations (p<0.001). The immunosuppressive therapy administered to children with liver transplantation was tacrolimus in 11 patients and cyclosporine in one patient, while all 10 children with kidney transplantation received tacrolimus plus mycophenolate. The most common antigenic food was egg. The natural killer (NK) cell numbers were significantly higher in liver-transplant children than in kidney-transplant children. No significant differences were found in the serum cytokine levels.

CONCLUSIONS

This study confirms that liver-transplant children treated with tacrolimus alone have a higher risk of developing TAFA than kidney-transplant children treated with tacrolimus plus mycophenolate. NK cells might be involved in this difference.

De Novo Allergy and Immune-Mediated Disorders Following Solid-Organ Transplantation-Prevalence, Natural History, and Risk Factors

OBJECTIVES

To describe the prevalence, natural course, outcome, and risk factors of post-transplant de novo allergy and autoimmunity.

STUDY DESIGN

A cross-sectional, cohort study of all children (<18 years) who underwent a solid-organ transplantation, between 2000 and 2012, in a single transplant center, with a follow-up period of 6 months or more post-transplant and without history of allergy or immune-mediated disorder pretransplant.

RESULTS

A total of 626 eligible patients were screened, and 273 patients (160 males; 59%) met the inclusion criteria; this included 111 liver, 103 heart, 52 kidney, and 7 multivisceral recipients. Patients were followed for a median period of 3.6 years. A total of 92 (34%) patients (42 males, 46%) developed allergy or autoimmune disease after transplantation, with a high prevalence among liver (41%), heart (40%), and multivisceral (57%) transplant recipients compared with kidney recipients (4%; P < .001). Post-transplant allergies included eczema (n = 44), food allergy (22), eosinophilic gastrointestinal disease (11), and asthma (28). Autoimmunity occurred in 18 (6.6%) patients, presenting mainly as autoimmune cytopenia (n = 10). In a multivariate analysis, female sex, young age at transplantation, family history of allergy, Epstein-Barr virus infection, and elevated eosinophil count >6 months post-transplantation were associated with an increased risk for allergy or autoimmunity. Two patients (0.7%) died from autoimmune hemolytic anemia and hemophagocytic lymphohistiocytosis, and 52 episodes of post-transplant allergy, autoimmunity, and immune-mediated disorders (37%) did not improve over time.

CONCLUSIONS

Allergy and autoimmunity are common in pediatric liver, heart, and multivisceral transplant recipients and pose a significant health burden. Further studies are required to clarify the mechanisms behind this post-transplant immune dysregulation.

Post-transplantation Development of Food Allergies

PURPOSE OF REVIEW

The development of food allergies is increasingly being recognized as a post-solid organ transplant complication. In this article, we review the spectrum of post-transplant food allergy development and the proposed mechanisms for de novo food allergies and the clinical significance they pose.

RECENT FINDINGS

The development of new food allergies is disproportionately associated with pediatric liver transplants, where it occurs in up to 38% of select populations. The mechanism of food allergy development is not completely understood; however, it is likely promoted by unbalanced immune suppression. De novo food allergy development is a common complication of solid organ transplants with the highest risk occurring in pediatric liver transplant recipients. There are likely multiple mechanisms for food allergy development including passive transfer of membrane-bound IgE and lymphocytes from donor to recipient, as well as loss of food tolerance and active development of new food allergies. The optimal management of food allergies following organ transplants has not been well researched but may include changing the immune suppression regimen if the food allergy does not resolve without intervention.

Transplant-acquired food allergy: current perspectives

Mechanisms that regulate the tolerance to dietary proteins or the loss of this and subsequent development of disease are poorly understood. In food allergy, there is growing awareness of the urgency in understanding these events to aid in the development of next-generation therapies and interventions. This review focuses on the accumulating evidence related to food allergy that develops after transplantation. This intriguing immunological phenomenon has been described in several different types of transplant settings and to variety of different foods. We outline these studies and the evidence from them that support transplant-acquired food allergy being a process regulated by both the donor allergic status and the recipient genetics and treatments. A number of key risk factors seem prevalent throughout transplant-acquired food allergy and include type of transplant, age and general health of the recipient, modality of immunosuppression and potentially the genetics of both donor and recipient. Importantly, these studies provide a window into better general understanding of food allergy, and facilitate clearer understanding of the critical immunological and epidemiological factors needed to allow the adoptive transfer of a food-specific allergic disease from one individual to another.

Raised immunoglobulin A and circulating T follicular helper cells are linked to the development of food allergy in paediatric liver transplant patients

BACKGROUND

Post-transplant food allergy (LTFA) is increasingly observed after paediatric liver transplantation (LT). Although the immunopathology of LTFA remains unclear, immunoglobulin (Ig) E seems to be implicated.

OBJECTIVE

To study humoral and cellular immunity in paediatric LT patients in search for factors associated with LTFA, and compare with healthy controls (HC) and non-transplant food-allergic children (FA).

METHODS

We studied serum Ig levels in 29 LTFA, 43 non-food-allergic LT patients (LTnoFA), 21 FA patients and 36 HC. Serum-specific IgA and IgE against common food allergens in LTFA, IgA1 , IgA2 and joining-chain-containing polymeric IgA (pIgA) were measured. Peripheral blood mononuclear cells were analysed by flow cytometry for B and T cell populations of interest.

RESULTS

Serum IgA and specific IgA were higher in LTFA compared to LTnoFA. LTFA patients had the highest proportion of circulating T follicular helper cells (cTfh). The percentage of cTfh correlated positively with serum IgA. Unique in LTFA was also the significant increase in serum markers of mucosal IgA and the decrease in the Th17 subset of CXCR5(-) CD4(+) cells compared to HC. Both LT patients exhibited a rise in IgA(+) memory B cells and plasmablasts compared to HC and FA.

CONCLUSIONS

LT has an impact on humoral immunity, remarkably in those patients developing FA. The increase in serum markers of mucosal IgA, food allergen-specific IgA and cTfh cells observed in LTFA, point towards a disturbance in intestinal immune homoeostasis in this patient group.

Management of tacrolimus-associated food allergy after liver transplantation

Increasingly, food allergy associated with tacrolimus after pediatric living-donor liver transplantation (LT) has been reported. Tacrolimus prevents the activation of T cells by blocking calcineurin, thus producing an immunosuppressive effect, but tacrolimus induces an imbalance in T-helper type 1 (Th1) and Th2 cells in the food allergy process. This report describes a case of tacrolimus-associated food allergy after pediatric living-donor LT. The patient was a 7-year-old Japanese girl who had undergone living-donor LT at 12 months of age, and whom we first saw in the clinic at age 18 months. She received immunosuppressive therapy by tacrolimus after transplantation. Atopic dermatitis developed in post-transplant month 18. Stridor, facial edema, lip swelling, and skin erythema after consuming tempura udon containing wheat occurred in post-transplant month 39, and she was subsequently diagnosed with anaphylactic shock. Eosinophilic leukocyte and serum immunoglobulin (Ig)E increased, and specific IgE was positive for some food allergens. Pharmacotherapy was therefore changed from tacrolimus to cyclosporine A, after which eosinophilic leukocyte and serum IgE decreased and atopic dermatitis improved.

Food allergies developing after solid organ transplant

The development of food allergy is an increasingly recognized form of morbidity after solid organ transplant. It occurs more commonly in liver transplant recipients, although it has also been reported in heart, lung, kidney, and intestinal transplants. Pediatric transplant recipients are more likely to develop symptoms compared to adults, and reports of frequency vary widely from 5% to 38% in pediatric liver transplant recipients. Multiple mechanisms have been proposed in the literature, although no single mechanism can yet account for all reported observations. As food allergy can have at worst potentially fatal consequences, and at best require lifestyle adjustment through food avoidance, it is important for recipients to be aware of the donor's food allergies and particularly in pediatrics, the possibility of completely de novo allergies. This review explores the recent reports surrounding food allergy after solid organ transplant, including epidemiology, proposed mechanisms, and implications for practice.

Cytokine profile of food-allergic post-liver transplant children is identified by high levels of IL-5 and low IL-10 secretion from patients' peripheral blood mononuclear cells

Severe allergic reaction to food following liver transplantation is a well-known phenomenon. However, the mechanisms underlying this phenomenon are not yet elucidated. This study aimed to reveal the nature of the immune response in post-transplanted allergic patients and compare them to non-allergic transplanted as well as allergic and non-allergic control subjects, with focus on cytokine milieu. Post-liver transplant patients with and without allergic reactions as well as food-allergic but otherwise healthy and healthy non-allergic control patients were recruited. We reviewed patient records and routine laboratory tests and assayed subjects' PBMCs, studying cytokine secretion profile in response to different stimuli. Post-transplant patients with food allergy showed a unique cytokine profile in response to various stimuli, with extremely elevated IL-5, low IL-10 secretion, and somewhat higher IFN-γ. T regulatory cell number was not significantly different among the groups of patients and controls. Immune response of food-allergic post-liver transplant patients is identified by a unique cytokine profile when compared to allergic but otherwise healthy individuals.

Increase in de novo food allergies after pediatric liver transplantation: tacrolimus vs. cyclosporine immunosuppression

Post-TAFA is an uncommon but serious complication of organ transplantation. This study aimed to compare the incidence of FA in CsA and tacrolimus-treated children following OLT and identify risk factors. The medical charts of all patients who underwent OLT at our institution were reviewed. Between 1985 and 2010, 218 OLTs were performed on 188 pediatric recipients, of which 154 were included in the study. Three patients (3%) of the 102 receiving CsA developed FA, compared with nine (17%) in the 52 tacrolimus-treated patients, the latter exceeding general population reported FA prevalence (RR 5.88; 95% CI: 1.66-20.81). All TAFA cases underwent transplantation before the age of three with an incidence of 29% (9/31) in the tacrolimus-treated children in comparison with 7% (3/41) in the CsA group (RR 3.97; 95% CI: 1.17-13.45). Eosinophilia was present in 81% of children receiving tacrolimus compared with 54% in the CsA group (p = 0.002). We observed a statistically significant increase incidence of FA in tacrolimus-treated children following an OLT and those under the age of three are particularly vulnerable. The underlying process is still unknown and probably multifactorial.

Clinical, endoscopic, and histologic features of eosinophilic inflammation of the gastrointestinal tract in pediatric liver transplant patients

Immunosuppression during the post-transplantation period has led to dramatic outcome improvements in PLTR patients. There have been reports describing the development of food allergies and an increased predilection for development of EGI in PLTR. We aimed to identify the clinical, endoscopic and histologic features of EGI in PLTR patients. In this retrospective case series we analyzed medical record of all PLTR who underwent EGD and/or colonoscopy at our institution from 2000 to 2006. From 2000 to 2006, 32 PLTR patients underwent endoscopic evaluation. Seventeen (53%) of 32 patients were diagnosed with EGI. Endoscopic abnormalities were seen in the esophagus, stomach, and small intestine in 11 (65%), 11 (65%), and four (24%) patients, respectively. Eosinophilic inflammation was seen in the esophagus, stomach, and small intestine in 13 (76%), 10 (59%), and five (29%) patients, respectively. Nine of 17 patients underwent colonoscopy and endoscopic abnormalities were seen in four (44%) patients. Five patients (56%) had eosinophilic inflammation. In conclusion, we have characterized the clinical, endoscopic, and histologic features of EGI. Histologic and endoscopic examination reveals that, when present, EGI is often found at multiple segments along the gastrointestinal tract.

New developments in transplant-acquired allergies

Transplant-acquired allergy (TAA) was firstly described as transplant-acquired food allergy (TAFA) after bone marrow transplantations and mostly observed in a transient form. The picture is complicated by numerous case reports of TAFA after the receipt of liver grafts from donors with no documented history of food allergy. The estimated prevalence of TAFA among young children in the literature has been documented in various studies ranging from 6% to 57%. Although TAA is mostly found to be associated with liver transplantation; it has been recently reported to be related with heart, intestinal, lung and even renal transplantations in adults. Previous reviews of published cases of liver TAA misleadingly emphasized the predominance of children and the absence of TAA in cardiac, pulmonary, and renal transplant recipients. In different studies, the male/female ratio is equal. Literature data suggest that children with TAFA typically present within the first year after surgery and are typically allergic to multiple foods. The pathogenesis of TAA is not still completely understood. Most of the studies support the concept that the functioning liver itself, and not only tacrolimus immunosuppression, is one of the main contributors to TAA in these patients. In the light of recent findings, other possible mechanisms can be summarized as following: (1) the recovery of delayed type hypersensitivity; (2) late manifestation of food allergy; (3) intestinal injury as well as inhibition of cellular energy production by tacrolimus; and (4) transfer of food-specific IgE or lymphocytes. Thus, interplay between hematopoietic cells from the transplanted organ and recipient specific factors (e.g., younger age and atopic background) seem to underlie the development of TAA. Most patients will have symptomatic improvement following reduced immunosuppression and an appropriately restricted diet. Nevertheless, some studies suggest that atopic diseases occur in some of pediatric liver transplant recipients, with manifestations including food allergy, eczema, allergic rhinitis, and asthma. More studies would be needed including greater number of patients to determine whether TAA is transient or not in pediatric/adult solid organ recipients.

Food allergy diagnosis and therapy: where are we now?

Food allergy is a growing worldwide epidemic that adversely effects up to 10% of the population. Causes and risk factors remain unclear and diagnostic methods are imprecise. There is currently no accepted treatment for food allergy. Therefore, there is an imminent need for greater understanding of food allergies, revised diagnostics and development of safe, effective therapies. Oral immunotherapy provides a particularly promising avenue, but is still highly experimental and not ready for clinical use.

Post-transplant food allergy in children is associated with liver and not with renal transplantation: a monocentric comparative study

Food allergy is increasingly reported after paediatric liver transplantation. The underlying physiopathological mechanism remains incompletely understood. Therefore, we aimed to determine the incidence, clinical presentation, possible risk factors, and prognosis of post-transplant food allergy in children currently followed after liver and renal transplantation. The study population consists of 49 liver and 21 renal transplant patients transplanted between the age of 22 months and 15 years. Data were collected retrospectively from medical records and via a doctor's questionnaire taken from the parents in a monocentric setting. Post-transplant food allergy has developed in 13 liver transplant patients and in none of the renal transplant recipients. Within the liver transplant group, median age at liver transplantation is significantly lower in the food-allergic (10 months) versus non-food-allergic group (3.3 years; p = 0.002). The use of tacrolimus as primary maintenance immunosuppression is associated with food allergy (p = 0.032) and mean donor age is significantly lower in the food-allergic group (p = 0.009). Compared to the renal transplant group, median age at transplantation is significantly lower in the liver patients (p < 0.001). No significant differences are found in primary immunosuppressive regimens between renal and liver transplant patients.

CONCLUSION

Post-transplant food allergy is an important clinical problem in children after liver transplantation which does not affect renal transplant patients despite similar immunosuppressive regimens. Within the group of liver transplant recipients, tacrolimus use, young age at time of transplant and younger donor age were associated with the development of food allergy.

Pathogenesis of food allergy in the pediatric patient

In the US and other developed countries, food allergy is a growing epidemic in pediatric populations with a substantial impact on health-related quality of life. As such, there are great efforts underway to unravel the mechanisms of oral mucosal tolerance and to better define the factors related to host and allergen exposure that contribute to the aberrant immune response leading to sensitization and clinical food allergy. Although more research is needed to eventually develop targeted treatment and prevention strategies, this review highlights our current understanding of the pathogenesis of IgE-mediated food allergy.

Pediatric allergy and immunology in Israel

After the geographic and sociodemographic settings as well as the health care in Israel are briefly described, the scope of pediatric allergy and immunology in Israel is presented. This includes specific disorders commonly encountered, the environment that induces symptoms, the specialists who treat them, and the common challenges of patients, parents, doctors, and allied health personnel who collaborate to manage the maladies and patient care. Allergies usually affect some overall 15-20% of the pediatric population. The main allergens are inhaled, ingested, or injected (insects stings). Generally, the incidence of the various allergens affecting children in Israel, is similar to other parts of the Western world. Owing to the high consanguinity rate in the Israeli population, the prevalence of the various immunodeficiency conditions (in the adaptive as well as the innate system) is higher than that reported worldwide. Pediatric allergists/immunologists also treat autoimmune disorders affecting the pediatric group. Pediatric allergy and clinical immunology are not separate specialties. The 25 specialists who treat children with allergic/immunologic diseases have undergone a basic training in Pediatrics. They also received an additional 2-yr training in allergy and clinical immunology and then have to pass the board examinations. They work mainly in pediatric allergy units, in several hospitals that are affiliated to the five medical schools in the country. Aside from clinical work, most of the centers are also heavily involved in clinical and basic research in allergy and immunology.

High prevalence of food sensitisation in young children with liver disease: a clue to food allergy pathogenesis?

BACKGROUND

The pathogenesis of food allergy is not completely understood - animal models suggest hepatic mechanisms may be important for immune tolerance to orally ingested antigens, but there is little direct evidence for this in humans.

OBJECTIVES

We investigated whether there is an association between liver dysfunction or transplantation in young children and IgE sensitisation to food.

METHODS

We evaluated paired pre- and post- liver transplant sera from children aged 0-36 months treated at a single centre during 2001-2008. Sera were assayed for total IgE and cow's milk, egg and peanut-specific IgE. We quantified hepatic dysfunction pre-transplant using the Paediatric End-stage Liver Disease (PELD) score. We also assessed 70 children after renal transplant to establish whether any association between liver transplant and food sensitisation was organ specific.

RESULTS

Paired sera were available from 50 of 94 children who had a liver transplant during the study period. 35 of 50 (70%) had IgE sensitisation (≥ 0.35 kUa/l) to ≥ 1 food pre-transplant and 18 (36%) post-transplant (p = 0.001). Ten (20%) children had food-specific IgE levels that carry high probability of challenge-confirmed food allergy pre-transplant. Food sensitisation pre-transplant was associated with severity of liver dysfunction [mean (s.d.) pre-transplant PELD score 1.52 (0.13) in food sensitised, 0.77 (0.22) in non-sensitised children p = 0.004]. Total IgE level was raised in 34/42 (81%) pre-transplant and fell significantly post-transplant. Interview assessment of the parents of 40 children revealed that 13 (33%) had a history consistent with food allergy. These findings were not replicated in the renal transplant group.

CONCLUSIONS

Young children with severe liver dysfunction appear to have a high prevalence of food sensitisation. Hepatic mechanisms may therefore be important for establishing immune tolerance to dietary antigens in humans.

De novo food sensitization and eosinophilic gastrointestinal disease in children post-liver transplantation

BACKGROUND

Children have increased prevalence of food allergy (FA) and eosinophilic gastrointestinal disease (EGID) following liver transplantation. The aim of this study was to identify related risk factors.

METHODS

Chart review of pediatric liver transplant (LT) recipients with de novo FA and/or EGID post-LT and non-allergic controls.

RESULTS

We identified 30 (8.5%) children with FA and/or EGID among 352 pediatric LT recipients. Median age at transplant was 0.9 inter-quartile range (IQR 0.6-2.0) years. FA developed at a median 1.0 (IQR 0.5-8.2) yr post-LT and manifested with gastrointestinal symptoms (53%) or urticaria/angioedema (40%). Commonly avoided foods included milk (60%), egg (57%), and peanut (47%). Of the 15 children with FA who underwent endoscopy, 11 had eosinophilic infiltrates in multiple segments of the esophagus alone or in combination with other bowel segments. FA and EGID were linked to transplantation at a younger age (median, 0.9 vs. 5.5 yr), higher frequency of blood eosinophilia, and prior history of rhinitis and atopic dermatitis. Tacrolimus use and tacrolimus serum levels were similar between allergic subjects and controls.

CONCLUSIONS

Findings suggest that exposure to tacrolimus alone post-LT is insufficient to initiate de novo allergic disease in LT recipients; rather, younger age and underlying predisposition to atopic disease may play larger roles.

Presentation of atopic disease in a large cohort of pediatric liver transplant recipients

Atopic disease occurs in solid organ transplant recipients with an increasingly recognized frequency. The time course for the development of these atopic diseases in liver transplantation has not been described. The objective was to characterize the atopic manifestations of children receiving chronic immunosuppression after orthotopic liver transplantation (OLT). Chart review and follow-up questionnaire were utilized for 176 OLT pediatric recipients at a single institution for manifestations of allergic disease. Atopic disease was present in 25 (14.2%) patients. Median age at transplant was 16 months with a median follow-up of 63 months. Food allergy and non-food related atopic symptoms presented at a median of 11.5 (IQR, 6-28) and 19 (IQR, 5-41) months post-transplantation, respectively. The median age at transplant of the non-atopic children was 72 months, higher than patients with atopy (p < 0.001). Food allergy and atopic skin disease symptoms were present in 40% and 56% of cases, respectively. Asthma, allergic rhinitis, or both were found in 66% of cases. The onset of symptoms of food allergy and eczema (median, 12 months post-transplantation) preceded symptoms of allergic rhinitis and asthma. (median of 27 and 30 months post-transplantation, respectively). Atopy occurs in ∼14% of pediatric liver transplant recipients, with manifestations including food allergy, eczema, allergic rhinitis, and asthma.

Transfer of peanut allergy following lung transplantation: a case report

This case study describes a patient who developed peanut allergy following lung transplantation. A 54-year-old woman underwent bilateral lung transplantation on June 2009 owing to severe chronic obstructive pulmonary disease. She had no history of food allergy before transplantation. The donor, however, was a 20-year-old man who was fatally injured during an automobile accident; he was allergic to peanuts. At 3 months after transplantation, the lung recipient presented with acute dyspnea and urticaria 15 minutes after consuming food containing peanut derivatives. Pre- and posttransplantation recipient blood samples analyzed for the presence of IgE antibodies specific for peanut allergens confirmed that the allergy had been passively transfered as a consequence of transplantation. Food allergy following solid organ transplantation is thought to be rare, mostly occurring in children. Two mechanisms may explain the observations described for the patient reported in this study: de novo development of peanut allergies after transplantation, or passive transfer of peanut allergies from a peanut-sensitized organ donor. This case report documenting pre- and posttransplantation IgE status in a lung transplantation case suggested that the allergic status of organ donors should be thoroughly assessed before transplantation, and potential allergy transfer risks must be discussed with the transplant team and the patient.

Autoimmune hemolytic anemia and idiopathic thrombocytopenic purpura in pediatric solid organ transplant recipients, report of five cases and review of the literature

Cytopenias are common among pediatric SOT; however, autoimmune cytopenias are infrequently reported. We report five cases of autoimmune cytopenias in pediatric LT patients: two with isolated IgG-mediated AIHA, two with ITP, and one with Evans syndrome (ITP and AIHA). All patients were maintained on tacrolimus as immunosuppression. Viral illness commonly preceded the autoimmune cytopenias. All patients responded well to medical therapy (steroids, intravenous immunoglobulin, and rituximab) and lowering tacrolimus serum level. Prognosis appears to be worse when more than one cell line (e.g., Evans syndrome) is affected, and/or there is no preceding viral illness. A critical literature review of autoimmune cytopenias in children following SOT is conducted. Autoimmune cytopenias are a rarely reported complication of pediatric SOT, but clinicians taking care of pediatric transplant recipients need to be aware of this complication.

Increase in de novo allergies after paediatric liver transplantation: the Brisbane experience

  Pediatric liver transplantation is a successful procedure with 10-yr survival rate of 70%; following transplantation, the emphasis on promoting good quality of life is important. The increasing prevalence of allergic disorders in the general population and an increase in food allergy following solid organ transplantation are described in patients, especially in children, but the contribution to morbidity post-OLT has not been addressed.

OBJECTIVES

Identifying the incidence de novo allergies post-OLT performed by QLTS over 11 yr.

METHODS

Comprehensive medical record review of OLT recipients during study period.

RESULTS

From 1st July 1998 to 1st August 2009, 78 children received 85 cadaveric OLT; 60 children survived. Allergic disease was documented in 24/60 (40%) survivors. De novo food allergies were diagnosed in 12/60 (20%) (Table 2), 9/12 occurred in children who were infants at time of transplant. Ten of 12 had severe allergies, six anaphylactic; 6/60 (10%) carry an EpiPen. Only 31/60 (51%) diagnosed are followed in Queensland, suggesting severe allergic disease in our cohort is an underestimate.

CONCLUSION

Serious allergic disease post-OLT is clinically important, especially in infants at time of transplant, and should be targeted for specialist allergist referral and risk management. [Table: see text].

Pathophysiology of food allergy

In this article we review the pathophysiology of food allergy, which affects 4% of US children and 2% of adults, and is increasing in prevalence. Most food allergens share certain specific physicochemical characteristics that allow them to resist digestion, thus enhancing allergenicity. During allergic sensitization, these allergens are encountered by specialized dendritic cell populations in the gut, which leads to T-cell priming and the production of allergen-specific IgE production by B cells. Tissue-resident mast cells then bind IgE, and allergic reactions are elicited when mast cells are reexposed to allergen. Adjacent IgE molecules bound to the surface of the mast cell become cross-linked, causing mast cell degranulation and release of powerful vasoactive compounds that cause allergic symptoms.

Mechanisms of immune tolerance relevant to food allergy

The intestine has an unenviable task: to identify and respond to a constant barrage of environmental stimuli that can be both dangerous and beneficial. The proper execution of this task is central to the homeostasis of the host, and as a result, the gastrointestinal tract contains more lymphocytes than any other tissue compartment in the body, as well as unique antigen-presenting cells with specialized functions. When antigen is initially encountered through the gut, this system generates a robust T cell-mediated hyporesponsiveness called oral tolerance. Although seminal observations of oral tolerance were made a century ago, the relevant mechanisms are only beginning to be unraveled with the use of modern investigational techniques. Food allergy is among the clinical disorders that occur from a failure of this system, and therapies that seek to re-establish tolerance are currently under investigation.

Food allergy

Food allergies affect up to 6% of young children and 3%-4% of adults. They encompass a range of disorders that may be IgE and/or non-IgE mediated, including anaphylaxis, pollen food syndrome, food-protein-induced enterocolitis syndrome, food-induced proctocolitis, eosinophilic gastroenteropathies, and atopic dermatitis. Many complex host factors and properties of foods are involved in the development of food allergy. With recent advances in the understanding of how these factors interact, the development of several novel diagnostic and therapeutic strategies is underway and showing promise.

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)-β 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-β 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.

Immunosuppressants: what's new?

PURPOSE OF REVIEW

Advances in surgical techniques and combinations of conventional immunosuppressants have made paediatric liver transplantation the success story it is today. However, the increasing numbers of survivors reaching adulthood highlight important issues of long-term quality of life and drug induced complications. The aim of this review is to describe the trends and advances in immunosuppression for paediatric liver transplantation over the last 12 months.

RECENT DEVELOPMENTS

As our knowledge of the immune cell populations and intracellular mechanisms involved in alloreactivity improves, induction immunosuppression has emerged as a powerful therapeutic manoeuvre to counter the initial alloimmune response. Many centres have adopted a more focused use of biological agents at induction to improve immunosuppression in the critical peritransplant period and to reduce the level of subsequent maintenance requirements. Corticosteroid avoidance and calcineurin inhibitors minimization trials have obtained encouraging results. New immunosuppressive strategies have evolved towards the goal of inducing operational tolerance, and paediatric liver transplant recipients seem to be a particularly promising target. New strategies are being developed also to improve quality of life and reduce nonadherence in adolescents and young adults who underwent liver transplantation. New drugs target B-cell and complement driven rejection and new monoclonal antibodies and small molecules are under trial to inhibit specific signals in the immune response.

SUMMARY

We review current trends of immunosuppressive protocols in paediatric liver transplantation, focusing on induction agents, corticosteroid avoidance and calcineurin inhibitor sparing protocols, protocols for adult transition and new drugs currently under development.

CD25 appears non essential for human peripheral T(reg) maintenance in vivo

Background

IL-2 has been reported to be critical for peripheral T_reg survival in mouse models. Here, we examined T_reg maintenance in a series of paediatric liver transplant recipients who received basiliximab, a therapeutic anti-CD25 monoclonal antibody.

Methodology/Principal Findings

FoxP3⁺ CD4 T cells were analyzed by flow cytometry before liver grafting and more than 9 months later. We found that in vivo CD25 blockade did not lead to T_reg depletion: the proportion of FoxP3⁺ cells among CD4 T cells and the level of FoxP3 expression were both unchanged. IL-2Rβ expression was enhanced in FoxP3⁺ cells both before and after basiliximab treatment, while the level of IL-2Rγ expression was similar in T_regs and non-T_regs. No significant change in the weak or absent expression of IL-7Rα and IL-15Rα expression on FoxP3⁺ cells was observed. Although the proportion of FoxP3⁺ cells among CD4 T cells did not vary, food allergies occurred more rapidly after liver grafting in patients who received basiliximab, raising questions as to T_reg functionality in vivo in the absence of functional CD25.

Conclusions

CD25 appears non essential for human T_reg peripheral maintenance in vivo. However, our results raise questions as to T_reg functionality after therapeutic CD25 targeting.

The immunologic basis for gastrointestinal food allergy

PURPOSE OF REVIEW

Food allergies are common in children, although rare in adults. They can be life threatening via anaphylaxis, especially to peanut, and cause distress to children and parents because of the disease itself, and then through the difficulty of pursuing a strict elimination diet. In parents/carers and adults, this has significant impact on quality of life. The purpose of this review is to determine the therapeutic potential and current treatments for these conditions by understanding and manipulating the immune response.

RECENT FINDINGS

The single largest change in attitude to food allergies has been the realization that delaying exposure to foods may be harmful in terms of immune sensitization. Instead, strategies aimed at early introduction of foods to induce oral tolerance are now being re-evaluated. At the same time, very encouraging results are being obtained in desensitizing allergic children via oral tolerance. The aim of this strategy is not necessarily to induce complete tolerance to foods in allergic children but to raise the threshold dose at which adverse events occur, to minimize reactions to trace amounts of allergens.

SUMMARY

Food allergies are now recognized as being a treatable component of the atopic march.