Elevated Atopic Comorbidity in Patients with Food Protein-Induced Enterocolitis.

BACKGROUND: Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy. Its relationship to the major atopic manifestations (atopic dermatitis [AD], IgE-mediated food allergy [IgE-FA], allergic rhinitis [AR], asthma) is not understood. OBJECTIVE: To determine the clinical characteristics, epidemiologic features, and natural history of FPIES in relation to the major atopic manifestations. METHODS: We examined our primary care birth cohort of 158,510 pediatric patients, of whom 214 patients met 2017 FPIES diagnostic criteria. We measured the influence of FPIES on developing subsequent atopic disease. RESULTS: Pediatric FPIES incidence was between 0.17% and 0.42% depending on birth year. As in prior reports, most patients had an acute presentation (78%), and milk, soy, oat, rice, potato, and egg were common triggers. The mean age of diagnosis was 6.8 months. Atopic comorbidity was higher in patients with FPIES compared with healthy children (AD, 20.6% vs 11.7%; IgE-FA, 23.8% vs 4.0%; asthma, 26.6% vs 18.4%; AR, 28.0% vs 16.7%; P < .001 χ2). However, longitudinal analyses indicated that prior FPIES did not influence the rate of atopy development. CONCLUSIONS: The incidence of FPIES in our cohort was initially low, but is increasing. Food allergen distribution, presentation, and age of onset are similar to prior reports. Patients with FPIES have high rates of atopic comorbidity. However, longitudinal analysis does not support direct causation as the etiology of these associations. Rather it suggests a shared predisposition to both types of allergy, or associative bias effects. This work refines our understanding of the natural history of FPIES by elucidating associations between FPIES and atopy.

Common variable immunodeficiency-associated endotoxemia promotes early commitment to the T follicular lineage.

BACKGROUND: Although chiefly a B-lymphocyte disorder, several research groups have identified common variable immunodeficiency (CVID) subjects with numeric and/or functional TH cell alterations. The causes, interrelationships, and consequences of CVID-associated CD4+ T-cell derangements to hypogammaglobulinemia, autoantibody production, or both remain unclear. OBJECTIVE: We sought to determine how circulating CD4+ T cells are altered in CVID subjects with autoimmune cytopenias (AICs; CVID+AIC) and the causes of these derangements. METHODS: Using hypothesis-generating, high-dimensional single-cell analyses, we created comprehensive phenotypic maps of circulating CD4+ T cells. Differences between subject groups were confirmed in a large and genetically diverse cohort of CVID subjects (n = 69) by using flow cytometry, transcriptional profiling, multiplex cytokine/chemokine detection, and a suite of in vitro functional assays measuring naive T-cell differentiation, B-cell/T-cell cocultures, and regulatory T-cell suppression. RESULTS: Although CD4+ TH cell profiles from healthy donors and CVID subjects without AICs were virtually indistinguishable, T cells from CVID+AIC subjects exhibited follicular features as early as thymic egress. Follicular skewing correlated with IgA deficiency-associated endotoxemia and endotoxin-induced expression of activin A and inducible T-cell costimulator ligand. The resulting enlarged circulating follicular helper T-cell population from CVID+AIC subjects provided efficient help to receptive healthy donor B cells but not unresponsive CVID B cells. Despite this, circulating follicular helper T cells from CVID+AIC subjects exhibited aberrant transcriptional profiles and altered chemokine/cytokine receptor expression patterns that interfered with regulatory T-cell suppression assays and were associated with autoantibody production. CONCLUSIONS: Endotoxemia is associated with early commitment to the follicular T-cell lineage in IgA-deficient CVID subjects, particularly those with AICs.

Food Protein-Induced Enterocolitis Syndrome Food Challenges: Experience from a Large Referral Center.

BACKGROUND: Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy that is diagnosed based on clinical findings, but can be confirmed with oral food challenge (OFC). OFC is more often performed to assess the development of tolerance. Most studies describing OFCs in FPIES are limited in size. OBJECTIVE: We sought to describe our experience with OFCs using our FPIES protocol. Patients were given one-third of serving size with a 4-hour observation period, followed by home titration to full dose. METHODS: We conducted a retrospective chart review of patients who underwent OFC via the FPIES protocol from 2014 to 2017. Data regarding the history of reaction, age at the time of challenge, and reactions during challenge or with home introduction were collected. RESULTS: A total of 169 OFCs were completed under the FPIES protocol, in 119 patients to 19 different foods. Thirty challenges (18%) were positive, with 17 challenges (10%) during initial challenge and 13 (7.7%) during home dosing. Most reactions during initial challenge required intravenous fluids (IVF), but hypotension was uncommon. One hundred thirty-nine (82%) OFCs were negative with home introduction, indicating tolerance to the challenged foods. The mean age of passing a challenge to milk, soy, and grain was earlier than that of other solid foods. CONCLUSIONS: Our data suggest that our FPIES OFC protocol is safe. Early administration of IVF may prevent the development of hypotension. It is difficult to stratify the risk of severe or delayed reaction based on patient characteristics, and more data are needed to identify those appropriate for home introduction.

Food protein-induced enterocolitis syndrome: insights from review of a large referral population.

BACKGROUND: Food protein-induced enterocolitis (FPIES) is a rare non-IgE mediated disease. Most studies have been limited in nature, with the largest cohort being 66 patients. The most common foods that have been reported are milk and soy. OBJECTIVE: A retrospective chart review of patients seen in the Allergy Section at The Children's Hospital of Philadelphia with International Classification of Diseases Ninth Revision code of 558.3 (Allergic Gastroenteritis and Colitis) between 2007 and 2012 was conducted to identify patients with suspected FPIES. Diagnosis of FPIES was confirmed based on meeting clinical criteria of delayed reaction with pronounced vomiting and/or diarrhea. Data regarding patient characteristics and features of their reactions were collected for analysis and comparison with existing studies. RESULTS: A total of 462 cases were identified in our chart review. Patients had a similar demographic profile to the normal allergy patients seen in our clinic. The most common foods identified were milk (67%), soy (41%), rice (19%), oat (16%), and egg (11%). Patients had onset of FPIES to milk and soy around 7 months of age compared with 12 months of age for solid foods. FPIES reactions were identified to meats, tree nuts, peanuts, fruits, and vegetables; 70% of the patients reacted to one or two foods. Skin prick testing and atopy patch testing were not helpful in identifying the foods. CONCLUSION: FPIES reactions were seen more frequently than previously described. However, the presentation and clinical features were similar to previous reports. Milk- and soy-triggered FPIES were common, and 43.5% of patients who had a milk trigger reacted to soy. There is no laboratory test to identify foods that cause FPIES, and clinician-supervised oral food challenge is the only definitive test available.