Diagnostic value of scratch-chamber test, skin prick test, histamine release and specific IgE in birch-allergic patients with oral allergy syndrome to apple

Comprehensive review of pollen-food allergy syndrome: Pathogenesis, epidemiology, and treatment approaches

Pollen-food allergy syndrome (PFAS) is caused by cross-reaction of a specific pollen antigen with the corresponding food allergen in sensitized individuals. The manifestations are usually limited to oral symptoms; however, sometimes, rhinitis, respiratory and skin symptoms, and anaphylactic shock may occur. In PFAS pathogenesis, when food containing protein antigens (pan-allergens) with high homology to pollen antigens is ingested, mast cells bound to pollen antigen-specific IgE distributed in the oral mucosa cross-react with the food antigen, causing a local type I allergic reaction. The prevalence of PFAS depends on the geographic conditions, such as the type and amount of pollen in the area. PFAS is prevalent in all regions owing to the wide variety of pollen antigens implicated in the disease, such as alder and grass pollen, even outside of the birch habitat area. Basic research on PFAS is expected to significantly contribute to elucidating the pathogenesis and development of therapeutic strategies for PFAS. Currently, effective treatment for patients with PFAS that allows safe consumption of raw foods is lacking, and avoiding the intake of causative foods is the basis of prevention. Furthermore, allergen immunotherapy for PFAS has not yet been established, but various attempts are underway to develop it into a novel treatment strategy. This review highlights the current research landscape on the pathophysiology, epidemiology, and clinical aspects of PFAS. We outline the research gaps that should be addressed to improve the outcomes of patients with PFAS.

Pollen-food allergy syndrome in children

Pollen-food allergy syndrome (PFAS) is an immunoglobulin E-mediated immediate allergic reaction caused by cross-reactivity between pollen and the antigens of foods-such as fruits, vegetables, or nuts-in patients with pollen allergy. A 42.7% prevalence of PFAS in Korean pediatric patients with pollinosis was recently reported. PFAS is often called oral allergy syndrome because of mild symptoms such as itching, urticaria, and edema mainly in the lips, mouth, and pharynx that appear after food ingestion. However, reports of systemic reactions such as anaphylaxis have been increasing recently. This diversity in the degree of symptoms is related to the types of trigger foods and the characteristics of allergens, such as heat stability. When pediatric patients with pollen allergy are treated, attention should be paid to PFAS and an active effort should be made to diagnose it.

Guidelines for diagnosis, prevention and treatment of hand eczema

The guidelines aim to provide advice on the management of hand eczema (HE), using an evidence- and consensus-based approach. The guidelines consider a systematic Cochrane review on interventions for HE, which is based on a systematic search of the published literature (including hand-searching). In addition to the evidence- and consensus-based recommendation on the treatment of HE, the guidelines cover mainly consensus-based diagnostic aspects and preventive measures (primary and secondary prevention). Treatment recommendations include non-pharmacological interventions, topical, physical and systemic treatments. Topical corticosteroids are recommended as first line treatment in the management of HE, however continuous long-term treatment beyond six weeks only when necessary and under careful me-dical supervision. Alitretinoin is recommended as a second line treatment (relative to topical corticosteroids) for patients with severe chronic HE. Randomized control trials (RCT) are missing for other used systemic treatments and comparison of systemic drugs in “head-to-head” RCTs are needed.The guidelines development group is a working group of the European Society of Contact Dermatitis (ESCD) and has carefully tried to reconcile opposite views, define current optimal practice and provide specific recommendations, and meetings have been chaired by a professional moderator of the AWMF (Arbeitsgemeinschaft der Wis-senschaftlichen Medizinischen Fachgesellschaften; Association of the Scientific Medi-cal Societies in Germany).No financial support was given by any medical company. The guidelines are expected to be valid until December 2017 at the latest.

"New" techniques for more sensitive patch testing?

The patch test is the mainstay of diagnosis in allergic contact dermatitis. In its nearly 120-year-long history, numerous efforts to standardize several methodical aspects proved successful. The aim was always to enhance the validity and reliability of patch testing. This article reviews modifications of the basic patch test technique for enhancing test sensitivity. We expand on the recently validated strip patch test, which is a modification that involves affixing tape strips to the skin and removing them prior to patch testing. Although it was first described in 1953, we proposed the first protocol for standardized performance of the "strip patch test." The protocol was then tested in studies. As a result, test sensitivity of standardized strip patch test versus patch test was increased. The protocol produced a uniform reduction in the thickness of the stratum corneum and a good inter-rater agreement. Additionally, there was evidence of a non-specific stimulation of the inflammatory epidermal system. With regard to patient history, the standardized strip patch test showed a vastly better sensitivity than the patch test with only marginally lower specificity. As a complementary measure to patch testing diagnostic accuracy could be improved significantly by performing the standardized strip patch test. Further studies are needed on the reproducibility of the standardized strip patch test.

Management of the patient with multiple food allergies

Food allergies affect 6% of children and 3% to 4% of adults in the United States. Although several studies have examined the prevalence of food allergy, little information is available regarding the prevalence of multiple food allergies. Estimates of prevalence of people allergic to multiple foods is difficult to ascertain because those with allergy to one food may avoid additional foods for concerns related to cross-reactivity, positive tests, or prior reactions, or they may be reluctant to introduce foods known to be common allergens. Diagnosis relies on an accurate history and selective IgE testing. It is important to understand the limitations of the available tests and the role of cross-reactivity between allergens. Allergen avoidance and readily accessible emergency medications are the cornerstones of management. In addition, a multidisciplinary approach to management of individuals with multiple food allergies may be needed, as avoidance of several food groups can have nutritional, developmental, and psychosocial consequences.

Oral allergy syndrome: a clinical, diagnostic, and therapeutic challenge

OBJECTIVES

To provide a review of the literature and discuss the clinical, pathophysiologic, diagnostic, and therapeutic challenges of oral allergy syndrome (OAS).

DATA SOURCES

English-language publications on OAS (and pollen-food allergy syndrome) were identified through MEDLINE and through the reference lists of each identified article and review.

STUDY SELECTION

Articles pertaining to OAS with respect to its varied clinical presentation, underlying pathophysiology, available and investigational diagnostic testing, and evidence-based treatment options were selected.

RESULTS

OAS occurs in patients with a prior cross-reactive aeroallergen sensitization and clinically presents with initial oralpharyngeal symptoms after ingestion of a triggering fruit or vegetable. Although controversial, these symptoms may progress to systemic symptoms outside the gastrointestinal tract in 8.7% of patients and anaphylactic shock in 1.7%. OAS's underlying pathophysiology may play a role in clinical presentation and outcome, depending on whether the cross-reactive protein is a heat-labile PR-10 protein, a partially labile profilin, or a relatively heat-stable lipid transfer protein. Diagnostic testing is variable based on the underlying food tested, but fresh food skin prick test typically has the highest sensitivity. Treatment centers on avoidance and the consideration of self-injectable epinephrine. Because of its relationship with a cross-reactive aeroallergen sensitization, subcutaneous immunotherapy and sublingual immunotherapy have also been therapeutically tried with mixed results.

CONCLUSION

OAS is a challenging diagnosis to the practicing allergist because of its many clinical, diagnostic, and therapeutic considerations. Understanding these challenges and their underlying mechanisms can facilitate a knowledgeable approach to treating an oral allergy patient.

Characterization of recombinant Mal d 4 and its application for component-resolved diagnosis of apple allergy

BACKGROUND

Profilins are ubiquitous panallergens that have been extensively characterized; yet, their clinical relevance is still unclear.

OBJECTIVE

The aim of the present study was to produce recombinant apple profilin (rMal d 4) and to evaluate its allergenic activity and its potency for component-resolved allergy diagnosis.

METHODS

Complementary DNA-derived Mal d 4 was cloned, expressed in Escherichia coli and subsequently purified via poly (l-proline) sepharose. A total of 28 sera from apple-allergic patients were used for IgE-ELISA, immunoblot, RAST and basophil histamine release (BHR) test. In addition, skin prick tests (SPTs) were performed in five patients.

RESULTS

Four different complementary DNA coding for apple profilin, Mal d 4, each with an open reading frame of 393 nucleotides, were identified. One isoform Mal d 4.0101 was expressed in Escherichia coli and subsequently purified. Mass spectroscopy revealed the expected mass of 13.826 for rMal d 4.0101, and circular dichroism analysis data were typical for a folded protein and small-angle X-ray scattering measurement identified the protein as a monomer. All the serum samples displayed IgE binding to rMal d 4.0101 in IgE ELISA, immunoblot and RAST. In immunoblotting, IgE binding to natural Mal d 4 was partially/completely inhibited by preincubation with rMal d 4.0101, and RAST values to apple extract were significantly reduced upon serum pretreatment with rMal d 4.0101. SPTs and BHR assays using purified rMal d 4.0101 were positive. Purified rMal d 4.0101 was destroyed within seconds when subjected to pepsin digestion.

CONCLUSIONS

Apple profilin complementary DNAs were identified. The physicochemical and allergenic properties of purified recombinant Mal d 4.0101 were evaluated showing that the recombinant protein was equal to the natural protein as shown by inhibition assays. Thus, Mal d 4 represents another example suitable for component-resolved diagnosis of food allergy.

Patients with drug reactions -- is it worth testing?

BACKGROUND

Unevaluated drug reactions that lead to the prescription of expensive alternative medication is the reason why the European Academy of Allergy and Clinical Immunology guidelines recommend verification. We evaluated whether a structured test procedure in patients with drug reactions is worth the potential risk.

METHODS

We retrospectively analysed the charts of a cohort of 291 (220 females/71 males) consecutive patients from January 2003 to June 2004, who presented at the department's allergy outpatient clinic with histories of drug reactions. Twenty-three patients reported more than one independent episode resulting in 325 cases. All patients underwent the following procedure: (1) detailed history; (2) skin test and/or beta-lactam-specific IgE and; (3) if inconclusive, each patient was offered provocation testing -- if needed with alternative medication.

RESULTS

We evaluated reactions to 130 antibiotics, 90 to nonsteroidal anti-inflammatory drugs, 36 to local anaesthetics and 69 to other drugs. An association between drug intake and reaction was confirmed in 100 and excluded in 157 cases. Fourteen of 104 drug provocation tests (DPT), among these four reactions to placebo, yielded positive results but were managed without difficulty. In 68 cases, the procedure remained inconclusive. Additionally, we recommended 197 safe alternative regimens to 85 patients. Overall, our test procedure resulted in clear-cut recommendations to 82.1% (239/291) of the patients.

CONCLUSIONS

A standardized work-up including DPTs in patients with drug reactions leads to clear-cut advice concerning future tolerability or avoidance of certain drugs including recommendations for alternative medication in the vast majority of patients at the cost of only a low risk of mild side effects.

Characterization and improvement of apple extracts for the diagnosis of apple IgE-mediated allergy

BACKGROUND

The production process of reliable fruit extracts is not well established.

OBJECTIVES

To improve the overall quality of apple extracts by reducing protein loss during the manufacturing process and to evaluate the improved extracts using in vivo and in vitro experiments.

METHODS

Two types of extracts were prepared from peels of Golden Delicious apples (Malus domesticus). Extract A was extracted, 1:2 wt/vol, for 30 minutes at 40 degrees C in 0.01 M phosphate-buffered saline, and extract B was extracted, 1:2 wt/vol, in phosphate-buffered saline with 20% polyvinylpolypyrrolidone and 2-mmol/L EDTA. Both extracts were filtered, dialyzed in 3.5-kDa dialysis membranes, and lyophilized. The antigenic and allergenic profiles were analyzed using immunoblot and enzyme-linked immunosorbent assay. Nine patients clinically sensitive to apples and 12 controls underwent skin testing with both extracts.

RESULTS

Extracts A and B had dry weight yields of 0.71% and 1.86% and protein contents of 104.6 and 257 microg/mg of freeze-dried material, respectively. A steady and progressive loss of protein, greater in extract A than in extract B, was detected at different intervals during the manufacturing process of both extracts. Extract B produced larger wheal sizes than extract A (P = .008). Enzyme-linked immunosorbent assay inhibition results confirmed that extract B had a greater inhibition capacity than extract A.

CONCLUSIONS

A progressive loss of protein content occurs during the manufacturing of apple extracts. Wheal sizes induced by extract B were significantly larger than those induced by extract A and prick-by-prick solutions. Extract B was also more potent in vitro than extract A.

The effect of thermal processing on the IgE reactivity of the non-specific lipid transfer protein from apple, Mal d 3

BACKGROUND

Non-specific lipid transfer proteins (LTPs) are involved in allergy to fresh and processed fruits. We have investigated the effect of thermal treatment and glycation on the physico-chemical and IgE-binding properties of the LTP from apple (Mal d 3).

METHODS

Mal d 3 was purified from apple peel and the effect of heating in the absence and presence of glucose investigated by CD spectroscopy, electrospray and MALDI-TOF mass spectrometry. IgE reactivity was determined by RAST and immunoblot inhibition, SPT and basophil histamine release test.

RESULTS

The identity and IgE reactivity of purified Mal d 3 was confirmed. Mild heat treatment (90 degrees C, 20 min) in the absence or presence of glucose did not alter its IgE reactivity. More severe heat treatment (100 degrees C, 2 h) induced minor changes in protein structure, but a significant decrease in IgE-binding (30-fold) and biological activity (100- to 1000-fold). Addition of glucose resulted in up to four glucose residues attached to Mal d 3 and only a 2- and 10-fold decrease of IgE-binding and biological activity, respectively.

CONCLUSIONS

Only severe heat treatment caused a significant decrease in the allergenicity of Mal d 3 but glycation had a protective effect. The presence of sugars in fruits may contribute to the thermostability of the allergenic activity of LTP in heat-processed foods.

The oral allergy syndrome: improved diagnostic and treatment methods

PURPOSE OF REVIEW

The aim of this article is to review recent clinical and molecular findings related to the oral allergy syndrome in order to define its relevance in the field of food allergy, describe current diagnostic approaches and discuss attempts to use specific immunotherapy for treatment.

RECENT FINDINGS

New allergenic sources causing the oral allergy syndrome have been reported. Their allergenic molecules have been identified. In most of those studies oral allergy syndrome is reported as a clinical manifestation among more severe ones. Some of the molecules generally considered not to be at risk for severe reactions have been demonstrated to pose a threat for inducing generalized reactions. Some studies tried to assess the usefulness of immunotherapy with birch pollen extract by either subcutaneous or sublingual routes for the treatment of associated food allergies. In most of the cases, a well defined study design and a molecular approach at different study levels are lacking and thus the value of the obtained results is limited. To date, no final conclusion can be drawn on the basis of reported results.

SUMMARY

The knowledge about the highly prevalent phenomenon of oral allergy syndrome is still incomplete, in respect to both, epidemiology and foods inducing symptoms. It is very important to reach consensus on several aspects of this food-induced allergic disease. Further studies are required to highlight whether immunotherapy using co-recognized inhalant allergens is an effective way of curative treatment, or if co-treatment with purified pollen-related food allergens will be required to obtain a long-lasting effect.

The clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults

BACKGROUND

Previous studies have described cross-reactivity between fresh fruits, vegetables and pollen. However, no data demonstrates the clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults with and without symptoms in the pollen season.

OBJECTIVE

The aim of this study was to estimate the clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults and to examine the diagnostic value of skin-prick test (SPT), histamine release and specific IgE compared with the outcome of oral challenge.

METHODS

In total, 936 unselected adults (female : male 479 : 457, median age 33.7 years) were examined for pollen sensitization and clinical cross-reactivity with pollen-related fruits and vegetables by questionnaire, SPT, histamine release, specific IgE and oral challenge.

RESULTS

The prevalence of pollen sensitization was 23.8% (n = 223). The probability of a clinical reaction to pollen-related foods in the respective pollen-sensitized groups was: 24% (birch), 4% (grass), 10% (mugwort), 35% (birch + grass), 8% (grass + mugwort) and 52% (birch + grass + mugwort). The odds ratio of a clinical reaction to pollen-related fruits and vegetables in symptomatic pollen-sensitized adults was as high as four times (birch + grass) the odds ratio of a clinical reaction in asymptomatic pollen-sensitized adults.

CONCLUSION

This study not only demonstrates a high prevalence of clinical reactions to fruits and vegetables in pollen-sensitized adults, but also a discrepancy between the prevalence of sensitization to fruits and vegetables and the clinical relevance in different pollen-sensitized groups with symptoms in the pollen season as a significant factor.

Skin prick test reactivity to supplemental enzymes in cystic fibrosis and pancreatic insufficiency

BACKGROUND

Patients with cystic fibrosis and pancreatic insufficiency take supplemental pancreatic enzymes of porcine or plant origin on a daily basis.

OBJECTIVE

The frequency of immediate skin prick hypersensitivity reactions to such enzymes and the correlations to gastrointestinal symptoms and nutritional status were assessed in a single center prospective descriptive study.

METHODS

Skin prick tests using five different freshly prepared porcine pancreatic enzyme preparations, one enzyme preparation of fungal origin, porcine meat and cat epithelia were performed in patients with cystic fibrosis and pancreatic insufficiency and in healthy control subjects.

RESULTS

Positive skin tests in the 48 patients with cystic fibrosis were no more frequent than in 21 control subjects. No correlations with the frequency of gastrointestinal symptoms, nutritional status and lung function were found.

CONCLUSION

Although immediate hypersensitivity reactions to pancreatic enzyme preparations in subjects with cystic fibrosis are not common, individuals with possible allergic reactions to supplemental enzymes should be identified by skin prick tests and in unclear cases by double-blind placebo-controlled provocation tests.

Flow cytometric analysis of in vitro activated basophils, specific IgE and skin tests in the diagnosis of pollen-associated food allergy

BACKGROUND

Specific immunoglobulin E (IgE) and commercially available skin prick tests have been demonstrated to be unreliable methods to diagnose pollen-associated food allergy. To evaluate the predictive value of the basophil activation test (BAT) in pollen-associated food allergy, the apple-mediated oral allergy syndrome (OAS) in patients with birch pollinosis was chosen as a representative model.

METHODS

Patients with birch pollen allergy and a history of apple-mediated OAS (OAS(+), n = 29), patients with birch allergic without OAS (OAS(-), n = 22), and healthy controls (HC, n = 10) without birch pollen allergy and OAS were included. Apple IgE was quantified by the CAP FEIA method. Skin prick tests were performed with a Jonagold apple extract. Flow cytometric analysis of basophils activated with the same Jonagold extract was based on double staining with anti-IgE/anti-CD63 monoclonal antibodies.

RESULTS

Comparison between OAS(+) subjects and HC showed sensitivities and specificities of 96% and 100% for apple IgE and 88% and 100% for the apple skin prick test, respectively. For the BAT, sensitivity and specificity were 100%. In contrast, when nonresponders on the BAT were considered, sensitivity decreased to 90%. In a separate analysis between OAS(+) and OAS(-) subjects, specificities decreased to 30% for apple IgE and to 80% for the apple skin test, respectively. The BAT reached a sensitivity of 88% and a specificity of 75%.

CONCLUSION

Flow cytometry-assisted quantification of in vitro basophil activation seems to be a reliable instrument in the diagnosis of this model of pollen-associated food allergy. In addition, this study reemphasizes that the specificity of diagnostic allergy tests decreases considerably when, apart from HC, control individuals with cross-reactive antibodies are included.