Disorders for which the allergist-immunologist is particularly well-qualified to treat

Within the pages of this issue, several articles are presented which highlight how the expertise of the allergist-immunologist serves the needs of the patient who suffers from allergic disease. Of the many diseases for which this expertise is called upon, food allergy is among the most challenging. Three novel articles dealing with food allergy in this issue serve to further illustrate the point. The first of these by Nowak-Węgrzyn describes two forms of non-IgE mediated food hypersensitivity in children: food protein-induced enterocolitis (FPIES) and allergic protocolitis.¹ Although the author provides reassuring evidence for the self-limited nature of allergic protocolitis with its ultimate disease resolution, a more protracted clinical disease course with a tenuous prognosis is seen when FPIES is associated with IgE-mediated food hypersensitivity.

The allergy theme is continued in the next two articles which address the role of food protein allergenicity in the pathogenesis of food allergy. Various aspects of peanut hypersensitivity have been addressed both in previous issues of the Proceedings^2–7 as well as in a recent publication in the New England Journal of Medicine which demonstrated a dramatic and paradoxical reduction in the prevalence of peanut allergy resulting from intervention with early dietary introduction of peanut.⁸ In this issue of the Proceedings, Bencharitiwong et al study the experimental modification of peanut proteins in an attempt to reduce allergenic potency.⁹ If further studies are able to build on their reported success, the potential effect of protein modification on the burden of food allergy could be substantial. Because of the significant beneficial clinical implications of peanut protein modification on allergenicity, the article by Bencharitiwong and coauthors was chosen for this issue's “For the Patient” section. This segment, found in the final pages of the print version of this issue and also available online, consists of a one page synopsis of a selected article, that is written in a readily comprehensible fashion to help patients better understand the content of the full article and its diagnostic and therapeutic implications. It is printed in a format to allow reproduction on the practitioner's letterhead for distribution to patients.

Although most food allergies are caused by food allergens which are proteinaceous in nature, carbohydrate moieties are being increasingly recognized. Based on this recent recognition, Song et al investigated the potential allergenicity of glycan from wheat gliadin in children with food allergies to wheat.¹⁰ They report a correlation of gliadin-specific and wheat-specific IgE, suggesting that the glycan component of gliadin might also contribute to its allergenicity as a possible carbohydrate epitope in wheat allergy.

Another core disease state for which the expertise of the allergist-immunologist is called upon is angioedema. Previous issues of the Proceedings have addressed unmet needs and treatment advances in hereditary angioedema (HAE).^11–22 Within the pages of the current issue appear four articles which provide new information on the familial occurrence, differential diagnosis and treatment of HAE. Despite the known predominant autosomal dominant inheritance of HAE, diagnostic testing remains underutilized in those potentially susceptible but currently undetected patient populations. In an insightfully designed study, Riedl et al performed diagnostic complement testing on untested first degree blood relatives of HAE patients and identified a substantial number of new cases.²³ Their work emphasizes the importance of testing family members of patients with HAE.

Continuing with the HAE theme, Banerji et al report on the patient's perspective of currently available HAE treatment options.²⁴ Using patient surveys, their analysis reveals that despite widespread patient access to on demand and prophylactic treatment options, a significant burden of the disease persists even in treated patients.

Turning to the physician perspective, one unmet need for physicians who treat HAE, is a paucity of data regarding the efficacy of new treatment modalities for the management of cutaneous angioedema attacks. Bork et al attempt to fill this void by performing an ad hoc analysis of efficacy data from the uncontrolled I.M.P.A.C.T.2 study.²⁵ The authors suggest that treatment of cutaneous HAE attacks with 20 IU/kg of plasma derived, nanofiltered C1-INH concentrate provides faster attack resolution compared to no treatment.

Bringing further clinical applicability to this collection of angioedema articles is the most recent installment of the Patient-Oriented Problem Solving “POPS” series, which, as per tradition, is written by an allergy-immunology fellow-in-training from one of the 73 US allergy-immunology training programs. The purpose of the POPS series is to provide an innovative and practical learning experience for the novice allergist-immunologist in-training using a didactic format of clinical presentation and deductive reasoning. In this issue's POPS, Patel and Baldwin lead the reader through this process, describing the evaluation of a 60-year-old woman with recurrent episodes of flushing, urticarial and angioedema.²⁶ This case report illustrates the complexity of the differential diagnostic process for this presentation and the importance of a detailed history, physical exam and appropriate laboratory assessment in arriving at a correct diagnosis.

According to established asthma guidelines, stepping down asthma therapy is advised for patients with well-controlled persistent asthma.²⁷ Despite this guidance, however, current protocols for stepping down therapy remain inadequately studied. This unmet need for evidence to assist in clinical decision making is addressed in the article by Rank et al who performed a systemic review and meta-analysis study with the goal of estimating the risk for asthma exacerbation in individuals with stable asthma who initiate treatment with a leukotriene receptor antagonist when stopping or reducing treatment with inhaled corticosteroids.²⁸ Despite an extensive literature search, the authors were able to find only one study which addressed this issue, thereby limiting any strong literature support for this form of step down strategy.

In contrast to disorders with elevated levels of IgE, areas in which the expertise of the allergist-immunologist is plentiful, relatively less is known of conditions where IgE levels are deficient. Selective IgE deficiency states are rare conditions, therefore, which can be viewed as the antithesis of the more commonly occurring hyper IgE disease states which the allergist-immunologist is called upon to treat. Conditions known to be associated with IgE deficiency include immune dysregulation and autoimmunity. In this issue, Magen et al provide novel information that IgE deficiency is also associated with a higher prevalence of arterial hypertension and atherosclerotic cardiovascular disease.²⁹

In summary, the collection of articles found within the pages of this issue provides yet another insight into important allergic, cutaneous and respiratory disorders afflicting patients whom the allergist-immunologist serves. In keeping with the overall mission of the Proceedings, which is to distribute timely information regarding advancements in the knowledge and practice of allergy, asthma, and immunology to clinicians entrusted with the care of patients, it is our hope that the articles found within this issue will continue to achieve this goal and will help foster enhanced patient management through efficient workup and optimal therapy for a great diversity of clinical problems. On behalf of the editorial board, we hope you will enjoy the diversity of literature offered in this issue of the Proceedings.