Non-IgE-Mediated Gastrointestinal Food Protein-Induced Allergic Disorders. Clinical Perspectives and Analytical Approaches

Non-IgE-mediated gastrointestinal food allergy (non-IgE-GI-FA) is the name given to a series of pathologies whose main entities are food protein-induced allergic proctocolitis (FPIAP), food protein-induced enteropathy (FPE), and food protein-induced enterocolitis syndrome (FPIES). These are more uncommon than IgE-mediated food allergies, their mechanisms remain largely unknown, and their diagnosis is mainly done by clinical history, due to the lack of specific biomarkers. In this review, we present the latest advances found in the literature about clinical aspects, the current diagnosis, and treatment options of non-IgE-GI-FAs. We discuss the use of animal models, the analysis of gut microbiota, omics techniques, and fecal proteins with a focus on understanding the pathophysiological mechanisms of these pathologies and obtaining possible diagnostic and/or prognostic biomarkers. Finally, we discuss the unmet needs that researchers should tackle to advance in the knowledge of these barely explored pathologies.

IGF-1 Haploinsufficiency Causes Age-Related Chronic Cochlear Inflammation and Increases Noise-Induced Hearing Loss

Insulin-like growth factor 1 (IGF-1) deficiency is an ultrarare syndromic human sensorineural deafness. Accordingly, IGF-1 is essential for the postnatal maturation of the cochlea and the correct wiring of hearing in mice. Less severe decreases in human IGF-1 levels have been associated with other hearing loss rare genetic syndromes, as well as with age-related hearing loss (ARHL). However, the underlying mechanisms linking IGF-1 haploinsufficiency with auditory pathology and ARHL have not been studied. Igf1-heterozygous mice express less Igf1 transcription and have 40% lower IGF-1 serum levels than wild-type mice. Along with ageing, IGF-1 levels decreased concomitantly with the increased expression of inflammatory cytokines, Tgfb1 and Il1b, but there was no associated hearing loss. However, noise exposure of these mice caused increased injury to sensory hair cells and irreversible hearing loss. Concomitantly, there was a significant alteration in the expression ratio of pro- and anti-inflammatory cytokines in Igf1^+/- mice. Unbalanced inflammation led to the activation of the stress kinase JNK and the failure to activate AKT. Our data show that IGF-1 haploinsufficiency causes a chronic subclinical proinflammatory age-associated state and, consequently, greater susceptibility to stressors. This work provides the molecular bases to further understand hearing disorders linked to IGF-1 deficiency.

Poor prognosis of food protein-induced enterocolitis syndrome to fish

BACKGROUND

Fish is the most common causative food of food protein-induced enterocolitis syndrome (FPIES) in Southern Europe. In children with FPIES, the development of tolerance varies according to the culprit food and specifically fish seems to have a poorer prognosis than other solid foods. We sought to evaluate the fish-FPIES resolution rate in children.

METHODS

A descriptive retrospective analysis of children with fish-FPIES, followed during the last 20 years, was performed. The offending fish, age and symptoms at onset, the coexistence of atopic diseases and FPIES to other foods were registered. All the children included had undergone an oral food challenge (OFC) with the offending fish. We recorded those children that overcame their fish-FPIES and those that did not outgrow the disease.

RESULTS

Seventy children were enrolled in this study (median age: 9 yo; IQR 6.4-13.8). Forty-two (60%) achieved tolerance to the offending fish with a median age of 4 years (IQR: 3-5). Among children ≤5 yo (n = 40), 35 (87.5%) developed tolerance; among 6-8yo (n = 14), 40% developed tolerance; and only 12.5% among those ≥9 yo (n = 16) developed tolerance. Twenty-eight children did not outgrow the disease (median age: 8.9 yo; IQR: 9-13.8). We did not find any statistical differences regarding the offending fish, presence of single vs multiple fish-FPIES, symptoms at the beginning, coexistence of other atopic diseases or the coexistence of other FPIES, between the children who overcame the disease and those who did not.

CONCLUSION

One in five children with FPIES to fish will not overcome the disease during childhood.

[123I]Ioflupane imaging in Caucasians and non-Caucasians: Are there any differences?

PURPOSE OF THE REPORT

To compare diagnostic performance of [¹²³I]ioflupane SPECT imaging in different racial groups. In previous registration trials of [¹²³I]ioflupane, 99% of the subjects enrolled were Caucasians.

MATERIALS AND METHODS

A multicenter retrospective case-control study was conducted to evaluate whether the diagnostic performance of [¹²³I]ioflupane SPECT imaging is different in non-Caucasians than in Caucasians matched by age, sex, and final clinical diagnosis. Subjects who had received an initial diagnosis of suspected Parkinson's disease (PD) or essential tremor (ET) and then underwent [¹²³I]ioflupane SPECT imaging to assist with the subject's final clinical diagnosis were enrolled. Each subject's image was rated as normal or abnormal by 3 blinded expert readers. The majority interpretation was then compared with the final clinical diagnosis. Diagnostic performance of [¹²³I]ioflupane SPECT imaging (as measured by positive percent agreement (equivalent to sensitivity), negative percent agreement (equivalent to specificity), overall percent agreement (OPA), and measures of inter-rater agreement) were compared between the Caucasian and non-Caucasian groups.

RESULTS

In total, 102 non-Caucasians (58 with PD and 44 with ET as a final clinical diagnosis) and 102 Caucasians (58 with PD, 43 with ET, and 1 with "other") were included in the intent-to-diagnose (ITD) population. There was no significant difference between Caucasians and non-Caucasians in the diagnostic performance of [¹²³I]ioflupane SPECT imaging as measured by sensitivity, specificity, OPA, and measures of inter-rater agreement.

CONCLUSION

In this study, the diagnostic performance of [¹²³I]ioflupane SPECT imaging was comparable between Caucasians and non-Caucasians.

AR101 Oral Immunotherapy for Peanut Allergy

BACKGROUND

Peanut allergy, for which there are no approved treatment options, affects patients who are at risk for unpredictable and occasionally life-threatening allergic reactions.

METHODS

In a phase 3 trial, we screened participants 4 to 55 years of age with peanut allergy for allergic dose-limiting symptoms at a challenge dose of 100 mg or less of peanut protein (approximately one third of a peanut kernel) in a double-blind, placebo-controlled food challenge. Participants with an allergic response were randomly assigned, in a 3:1 ratio, to receive AR101 (a peanut-derived investigational biologic oral immunotherapy drug) or placebo in an escalating-dose program. Participants who completed the regimen (i.e., received 300 mg per day of the maintenance regimen for approximately 24 weeks) underwent a double-blind, placebo-controlled food challenge at trial exit. The primary efficacy end point was the proportion of participants 4 to 17 years of age who could ingest a challenge dose of 600 mg or more, without dose-limiting symptoms.

RESULTS

Of the 551 participants who received AR101 or placebo, 496 were 4 to 17 years of age; of these, 250 of 372 participants (67.2%) who received active treatment, as compared with 5 of 124 participants (4.0%) who received placebo, were able to ingest a dose of 600 mg or more of peanut protein, without dose-limiting symptoms, at the exit food challenge (difference, 63.2 percentage points; 95% confidence interval, 53.0 to 73.3; P<0.001). During the exit food challenge, the maximum severity of symptoms was moderate in 25% of the participants in the active-drug group and 59% of those in the placebo group and severe in 5% and 11%, respectively. Adverse events during the intervention period affected more than 95% of the participants 4 to 17 years of age. A total of 34.7% of the participants in the active-drug group had mild events, as compared with 50.0% of those in the placebo group; 59.7% and 44.4% of the participants, respectively, had events that were graded as moderate, and 4.3% and 0.8%, respectively, had events that were graded as severe. Efficacy was not shown in the participants 18 years of age or older.

CONCLUSIONS

In this phase 3 trial of oral immunotherapy in children and adolescents who were highly allergic to peanut, treatment with AR101 resulted in higher doses of peanut protein that could be ingested without dose-limiting symptoms and in lower symptom severity during peanut exposure at the exit food challenge than placebo. (Funded by Aimmune Therapeutics; PALISADE ClinicalTrials.gov number, NCT02635776 .).

Adjuvants in Allergen-Specific Immunotherapy: Modulating and Enhancing the Immune Response

Allergen-specific immunotherapy (AIT) is the only treatment that can affect the natural course of allergic diseases such as allergic asthma, allergic rhinitis, and IgE-mediated food allergy. Adjuvants are used to induce a quicker, more potent, and longer-lasting immune response. Only 4 compounds are used as adjuvants in currently marketed AIT products: aluminum hydroxide, calcium phosphate, microcrystalline tyrosine (MCT), and monophosphoryl lipid A (MPL). The first 3 adjuvants are delivery systems with a depot effect, although they may also have immunomodulatory properties. These first-generation adjuvants are still widely used, especially aluminum hydroxide. However, aluminum is subject to limitations. MCT is the depot formulation of L-tyrosine; it enhances IgG production without inducing a significant increase in IgE, is biodegradable, and has good local and systemic tolerability. In turn, MPL is an immunostimulatory agent that is the only second-generation adjuvant currently used for AIT. In addition, multiple adjuvants are currently being studied, including immunostimulatory sequences (ISSs), nanoparticles (liposomes, virus-like particles, and biodegradable polymers), and phosphatidylserine derivatives. In a murine model of allergic bronchial inflammation by sensitization to olive pollen, the specific IgE level was significantly higher in sensitized mice treated with olive pollen and aluminum hydroxide. However, specific IgE levels were significantly reduced and bronchial hyperreactivity significantly improved in sensitized mice treated with olive pollen and bacterial derivatives (MPL or ISSs).

Social Media as a Tool for the Management of Food Allergy in Children

BACKGROUND

Food allergy markedly impairs quality of life, and avoiding the offending food requires extensive patient education. Social media have been proven a useful source of information for other chronic conditions. Our aim was to describe how pediatric patients with food allergy and their families are using social media.

METHODS

We performed a cross-sectional study in the pediatric allergy unit of a tertiary hospital. Patients with food allergy were questioned about their disease and their use of social media. The survey was completed by the patients themselves in the case of those aged over 13 years and by parents or guardians in the case of younger patients.

RESULTS

We included 193 patients (162 guardians, 31 adolescents). Social media were used by 109 guardians (67.3%) and 29 adolescents (90.3%), of whom 30.3% and 6.9%, respectively, used them for food allergy-related purposes. The most popular websites were Facebook for guardians (52.2%) and YouTube for teenagers (80.6%). Having cow's milk and/or egg allergy was the only feature related to using social media for food allergy. Using social media for information on food allergy did not correlate with the frequency of recent reactions, self-scored knowledge about food allergy, or opinion on evidence-based or alternative therapies for the disease.

CONCLUSIONS

Most patients and guardians of patients with food allergy used social media. However, only a small portion accessed used them to increase their knowledge of the disease.

Anaphylaxis in Adolescent/Adult Patients Treated in the Emergency Department: Differences Between Initial Impressions and the Definitive Diagnosis

OBJECTIVES

To contrast the initial suspected etiology of anaphylaxis with the postworkup diagnosis in patients attended at the emergency department (ED) of a tertiary-level hospital in Spain and to investigate the incidence, causes, and management of anaphylaxis.

METHODS

We performed an observational study of patients aged more than 15 years who came to the ED with anaphylaxis between 2009 and 2010. All clinical records from the ED were reviewed. We recorded data on clinical management, the etiology proposed by the attending emergency physician, and the cause reported by the patient. The findings were compared with the diagnosis reached after the allergy workup.

RESULTS

The incidence of anaphylaxis was 0.08%. The most common manifestation was skin-mucosal symptoms (98.3%). Anaphylaxis was diagnosed in the ED in only 44% of the cases, regardless of severity. Only 39.7% received epinephrine, which was administered more frequently when the ED physician diagnosed anaphylaxis, regardless of severity. A total of 60 patients were subsequently seen at the allergy department. The final etiology differed from the initial suspicion in the ED in 45% of cases. The frequency of anaphylaxis of uncertain origin decreased from 33.3% to 13.3%. After the allergy workup, drugs (41.7%) were considered the main cause of anaphylaxis, followed by food (25%).

CONCLUSIONS

The incidence of anaphylaxis (0.08%) was double that estimated in the ED. Anaphylaxis is underdiagnosed. A correct diagnosis conditions the administration of epinephrine, regardless of the severity of symptoms. The real etiology of anaphylaxis should only be proposed after an allergy workup, which is recommended in all cases, as the real cause can differ considerably from the initial impression in the ED.

Evaluation of Rhodiola rosea supplementation on skeletal muscle damage and inflammation in runners following a competitive marathon

Adaptogens modulate intracellular signaling and increase expression of heat shock protein 72 (HSP72). Rhodiola rosea (RR) is a medicinal plant with demonstrated adaptogenic properties. The purpose of this study was to measure the influence of RR supplementation on exercise-induced muscle damage, delayed onset of muscle soreness (DOMS), plasma cytokines, and extracellular HSP72 (eHSP72) in experienced runners completing a marathon. Experienced marathon runners were randomized to RR (n=24, 6 female, 18 male) or placebo (n=24, 7 female, 17 male) groups and under double-blinded conditions ingested 600mg/day RR extract or placebo for 30days prior to, the day of, and seven days post-marathon. Blood samples were collected, and vertical jump and DOMS assessed the day before, 15min post- and 1.5h post-marathon. DOMS was also assessed for seven days post-marathon. Marathon race performance did not differ between RR and placebo groups (3.87±0.12h and 3.93±0.12h, respectively, p=0.722). Vertical jump decreased post-marathon (time effect, p<0.001) with no difference between groups (interaction effect, p=0.673). Post-marathon DOMS increased significantly (p<0.001) but the pattern of change did not differ between groups (p=0.700). Myoglobin (Mb), creatine phosphokinase (CPK), aspartate aminotransferase (AST), alanine aminotransferase (ALT), interleukin (IL)-6, IL-8, IL-10, monocyte chemotactic protein-1 (MCP-1), granulocyte-colony-stimulating factor (G-CSF), C-reactive protein (CRP), and eHSP72 all increased post-marathon (all p<0.001), with no group differences over time (all p>0.300). In conclusion, RR supplementation (600mg/day) for 30days before running a marathon did not attenuate the post-marathon decrease in muscle function, or increases in muscle damage, DOMS, eHSP72, or plasma cytokines in experienced runners.

Assessment of airway distribution of transnasal solutions in mice by PET/CT imaging

PURPOSE

Transnasal administration is one of the most common routes for allergen challenge in mouse models of airway diseases. Although this technique is widely used, neither the amount of allergen that reaches the lung nor its airway distribution has been well established. We used positron emission tomography (PET) and computed tomography (CT) to examine the anatomical distribution of a solution containing a tracer immediately after transnasal delivery and to determine the possible influence of age and administered volume.

PROCEDURES

Forty-six female BALB/c mice were divided into three groups according to instillation volume and age: (A) 15 microl, 8-10 weeks old (N = 10), (B) 30 microl, 8-10 weeks old (N = 20), and (C) 30 microl, 32 weeks old (N = 16). Anesthetized animals underwent a dynamic scan in a dedicated small-animal PET scanner immediately after transnasal administration of a solution containing (18)FDG. Regions of interest were used to obtain quantitative data. Animals were also imaged with a small-animal CT scanner to obtain complementary anatomical information.

RESULTS

Mean +/- SD (5.69 +/- 4.51%) of the solution administered reached the lungs in group A, 41.84 +/- 8.03% in group B, and 36.65 +/- 16.15% in group C. A comparable percentage was delivered to the left and right lungs in all the groups. Analysis of variance revealed a significant difference between the groups in the proportion of the solution that reached the lungs depending on the injection volume (P < 0.001), but not depending on animal age.

CONCLUSIONS

In this first report on quantitative imaging by PET and CT in small animals, we confirmed the suitability of the transnasal route with an instilled volume of 30 microl delivering fluids into the lower airways, although only about 40% of the dose reaches the lungs.

Pollen-induced airway inflammation, hyper-responsiveness and apoptosis in a murine model of allergy

BACKGROUND

Previous studies indicate that murine models are useful tools for studying the allergic diseases, including certain aspects of bronchial asthma such as cellular tissue inflammation and pulmonary function.

OBJECTIVE

To develop an experimental model of allergic lung inflammation based on a relevant human allergen, olive pollen, and to establish the immunological, cellular and functional airway features of the allergic response in this model.

METHODS

Induction of systemic allergic response was achieved by the subcutaneous administration of Olea europaea extract in BALB/c mice. Olea-specific Igs (IgG1, IgG2a and IgE) and cytokines from splenocyte cultures IL-4, IL-5 IL-10, IL-13 and IFN-gamma were measured. Allergic airway response was generated by transnasal instillation of the allergens. Airway responsiveness was monitored by non-invasive methacholine inhalation challenge. Lungs were paraffin embedded and histologically analysed. Apoptosis was studied by the TUNEL technique in the lung tissue and through cell cycle analysis by flow cytometry in splenocytes.

RESULTS

Our results demonstrate that Olea-sensitized mice develop a specific allergic antibody (IgG1 and IgE) and cytokine (IL-4, IL-5, IL-10 and IL-13) response. After transnasal Olea instillation, they show inflammatory infiltration of lung tissue, mucus secretion and non-specific hyper-responsiveness in the airway. Concomitantly, differences in the rate of apoptosis are observed in the lung cells as well as a significant reduction of spontaneous apoptosis in the splenocytes of allergic mice.

CONCLUSION

We present a novel animal model of olive pollen-allergic disease. This model presents traits associated with human allergic asthma and could be an interesting tool in the study of underlying molecular mechanisms and in exploring the therapeutic approaches to this disease.

Inhibition of chronic airway inflammation and remodeling by galectin-3 gene therapy in a murine model

We previously demonstrated that treatment of acute asthmatic rats with gene therapy using plasmid-encoding Galectin-3 (Gal-3) resulted in an improvement of cellular and functional respiratory parameters. The next question that we wanted to clarify was if in a chronic situation where the treated animal continues to inhale the Ag, does this procedure prevent the chronicity and the remodeling? Chronic inflammation was induced by intranasal administration of OVA over a period of 12 wk. In the treated group, the Gal-3 gene was introduced by intranasal instillation in 50 mul of plasmid-encoding Gal-3. Noninvasive airway responsiveness to methacholine was tested at different times. Cells were obtained by bronchoalveolar lavage and used for RNA extraction and cytometric studies. Eosinophils were counted in blood and bronchoalveolar lavage fluid. Real-time PCR was used to measure Gal-3 and cytokine mRNA expression in lung. Lungs were paraffined and histologic analyses were performed (H&E, periodic acid-Schiff, and Masson Trichrome stain). Our results showed that 12 wk after the first intranasal Ag instillation in chronically asthmatic mice, treatment with the Gal-3 gene led to an improvement in the eosinophil count and the normalization of hyperresponsiveness to methacholine. Concomitantly, this treatment resulted in an improvement in mucus secretion and subepithelial fibrosis in the chronically asthmatic mice, with a quantitatively measured reduction in lung collagen, a prominent feature of airway remodeling. Plasmid-encoding Gal-3 acts as a novel treatment for chronic asthma in mice producing nearly complete blockade of Ag responses with respect to eosinophil airway accumulation, airway hyperresponsiveness, and remodeling.

Anisakis simplex allergy: a murine model of anaphylaxis induced by parasitic proteins displays a mixed Th1/Th2 pattern

The study of the singular hypersensitivity reactions to Anisakis simplex (A.s) proteins, may help us to undestand many of the unknown immune interactions between helmiths infections and allergy. We have developed a murine model of allergy to A. simplex, that mimics human A. simplex allergy to study the specific aspects of anaphylaxis induced by parasites. Male C3H/HeJ mice were intraperitoneally sensitized to A. simplex. Mice were then intravenous or orally challenged with A. simplex. Antigen-specific immunoglobulins, polyclonal IgE, anaphylactic symptoms, plasma histamine levels and cytokine profiles were determined. Comparative IgE immunoblot analyses were also performed. Specific IgE, IgG(1) and IgG(2a) were detected in sensitized mice since week 3. Polyclonal IgE raised and peaked with different kinetics. Intravenous A. simplex challenge produced anaphylaxis in mice, accompanied by plasma histamine release. Oral A. simplex challenge in similarly sensitized mice did not caused symptoms nor histamine release. Numerous A. simplex allergens were recognized by sensitized mouse sera, some of them similar to human serum. The A. simplex stimulated splenocytes released IL-10, IFN-gamma, IL-4, IL-13 and IL-5. We describe a new animal model of anaphylaxis. It exhibits characteristics of type I hypersensitivity reactions to Anisakis simplex similar to those observed in allergic humans. Different responses to i.v. or oral A. simplex challenges emerged, which did not reflect a window tolerization period. The cytokine profile developed (mixed Th(1)/Th(2) pattern) differed from the observed in classical models of anaphylaxis or allergy to food antigens. This model may permit to investigate the peculiar allergic reactions to parasitic proteins.

Characterization of allergens secreted by Anisakis simplex parasite: clinical relevance in comparison with somatic allergens

BACKGROUND

Diagnostic methods for the study of allergic reactions to Anisakis simplex (A.s.) based on whole-body extracts of the larva are clearly insufficient.

OBJECTIVES

To study the allergenicity of the proteins secreted by the parasite. Comparison with somatic antigens and determination of their clinical importance in allergic patients were also addressed.

METHODS

An excretory/secretory (E/S) extract was produced by culturing third-stage A.s. larvae. It was used to perform immediate skin tests and to determine specific IgE in 10 patients diagnosed with allergy to A.s. Both tests were compared with the results obtained with the whole-body extract (somatic (S)). The molecular weight (MW) of their allergens was determined by immunoblotting, and a single-blind placebo-controlled oral challenge with E/S proteins was performed. Finally, allergens' resistance to gastric pepsin and acid pH was explored.

RESULTS

A.s. larvae secreted allergens more potent than those present in the S extract. The skin prick test wheal area produced by E/S molecules and the absorbance obtained in the determination of specific IgE with these allergens (ELISA) were 5.8 times bigger than those obtained with S extract. MW allergens of 72 and 56 kDa in E/S extracts and those of 56, 48 and 43 kDa in S extract were recognized by more than 50% of the patients. Partial cross-reactivity between them was revealed by immunoblotting inhibition studies. Oral challenge with E/S extract (up to 479 microg) was negative in all the patients. Treatment of E/S proteins with gastric pepsin inhibited the binding of the E/S allergens for specific IgE. The acid pH did not affect the overall binding of IgE to E/S extract. It decreased by 15.23% and 19.96% at pH 4 and 2, but the difference was not statistically significant.

CONCLUSION

A.s. secretes allergens more potent than somatic antigens and should be used in the diagnostic procedures. These allergens are inactivated by the pepsin, which supports the theory that live larva is necessary to induce an allergic reaction in most of the patients.

Is Anisakis simplex responsible for chronic urticaria?

The association of chronic urticaria (CU) to parasitic infestations has been poorly studied. Recently, sensitization to the parasite larva Anisakis simplex has been described as the cause of acute urticaria and anaphylaxis. The aim of this work was to study the relationship between sensitization to A. simplex and CU. One hundred one patients with CU were studied. Data of possible contacts with A. simplex were collected and the usual CU study was performed. Furthermore, total and specific immunoglobulin E (IgE; Pharmacia CAP system IGE fluorescence enzyme immunoassay: CAP) to A. simplex, Ascaris lumbricoides, Echinococcus granulosus, and Toxocara canis were determined as well as skin-prick test with A. simplex and serology to E. granulosus. In accordance with the results of the CAP to A. simplex, the patients were divided into two groups, positive and negative, and, subsequently, subdivided into two other subgroups that were alternatively told to stop eating fish or seafood in their diet or to continue with their normal diet. Checkups were performed at 6, 12, and 18 months. Thirty-five percent of the patients had positive skin tests to A. simplex, and CAP to A. simplex was positive in 55%. The fish-eating habits, acute or chronic gastrointestinal disease, and the background of abdominal surgery were not related to the results of the CAP and/or skin test to A. simplex. A total of 21.8% of all the patients had detectable CAP to A. lumbricoides, 91% of whom had positive CAP to A. simplex. Three patients had specific IgE to T. canis and five patients had specific IgE to E. granulosus, in the absence of positive serology. All had specific IgE to A. simplex. Present infestation could not be proved in any of them. The clinical evolution and variations of CAP to A. simplex and of total IgE were not statistically different among the groups during the 6, 12, and 18 months of the study. The percentage of sensitization to A. simplex in patients with CU is elevated and determines the sensitization to other parasites because of cross-reactivity. We have not found any causal relationship between the presence of specific IgE to A. simplex and CU. The clinical importance of this finding in this disease is still undetermined.

Immunostimulatory DNA-based therapeutics for experimental and clinical allergy

Although allergen immunotherapy (IT) has been shown to modulate allergic hypersensitivities, its efficacy is limited. Recently, in various models of experimental allergy, a number of reagents which we have termed immunostimulatory DNA-based therapeutics have proven highly effective in both the prevention and reversal of Th2 mediated hypersensitivity states. These include immunization with gene vaccines, allergen mixed with immunostimulatory oligodeoxynucleotide (ISS-ODN), and physical allergen: ISS-conjugates (AIC), and immunomodulation with ISS-ODN alone. Results from our laboratory have shown that immunostimulatory DNA-based therapeutics may be effective for the reversal of allergic hypersensitivity states in humans and several clinical trials have already been initiated. This review will focus on our laboratory's experience with immunostimulatory DNA-based therapeutics in various murine models of allergy and their potential utility in the treatment of allergic patients.

Dietary recommendations for patients allergic to Anisakis simplex

BACKGROUND

Anisakis simplex, a fish parasite, causes allergic urticaria, angioedema and anaphylactic shock through an IgE-mediated hypersensitivity mechanism. Consensus on the dietary recommendations that should be given to allergic patients is lacking. Our objective was to evaluate the usefulness of different types of diets in preventing further reactions in patients allergic to A. simplex.

METHODS

Twenty-eight adult patients, who had suffered an allergic episode caused by A. simplex were asked to follow one of the following three diets for a mean period of 13.16 months: a fish-free diet (diet 1; n = 19), a diet including fish frozen for more than 48 hours (diet 2; n = 9) and a diet with fresh fish (diet 3; n = 12). In all patients raw fish was excluded. Relapse rates and changes in total serum IgE and specific IgE to A. simplex were studied during the follow up.

RESULTS

During the 13-month follow-up none of the patients developed anaphylaxis. Urticaria symptoms were present in 5.8 %, 11.1 % (n.s) and 33.3 % (p = 0.016) of patients following diets 1, 2 and 3, respectively. Total IgE decreased by 64 % (p < 0.05), 48 % (p < 0.05) and 39.4 % (p < 0.05), respectively. Specific IgE to A. simplex decreased by 50.7 % (p < 0.05), 54.1 % (p < 0.05) and 23.6 % (p < 0.05) after diets 1, 2 and 3, respectively. No statistically significant differences were found among the groups in variations in total and specific IgE.

CONCLUSIONS

Patients allergic to A. simplex can eat fish that has been frozen at -20 C for 48 hours without risk of a severe allergic reaction. Long term decreases in specific and total IgE may not be good markers of eventual contact with A. simplex.

Clinical applications of (18)F-FDG in oncology

PET has emerged as a powerful diagnostic tool for the evaluation of cancer patients. Currently, most of these studies are performed with the glucose analog (18)F-FDG, which has been shown to accumulate avidly in most tumors. (18)F-FDG PET is now routinely used in the diagnosis, staging, and posttherapy evaluation of oncologic patients. After reading this paper, the reader should understand the physiologic basis of using (18)F-FDG in patients with different tumors, describe the role of this radiopharmaceutical in the management of oncologic patients, and identify those malignancies for which (18)F-FDG has proved to be effective in diagnosis and follow-up.

Bezafibrate-induced anaphylactic shock: unusual clinical presentation

We report a case of a patient who suffered generalized urticaria, chest tightness, wheezing, nausea, vomiting, hypotension, and loss of consciousness. Two hours earlier she had taken Eulitop Retard following lunch. She had tolerated all the implicated food after the reaction. Allergy evaluation revealed intense positive responses to intradermal tests with bezafibrate active component and Eulitop Retard (skin tests in control subjects were negative). Specific IgE tests (RAST) to Eulitop Retard were negative. An IgE mechanism is suggested to be responsible for this adverse reaction on the basis of the positive skin tets. The delayed onset (two hours) of this anaphylactic shock is unusual. Although infrequent, it may be caused by the specific pharmacokinetic characteristics of this drug, which is a slow releasing agent, mainly absorbed in the gut. The drug was taken just after lunch, and this concomitant food ingestion could also have produced a delay in gastric drainage and a retarded drug absorption. An IgE-mediated accelerated type reaction could also explain this delay. Apparently the patient reacted after the first contact to the drug, and the absence of a sensitization period is not usual in this type of immune reponse. Finally, we recommend the performance of prick and intradermal skin tests prior to any systemic challenge when allergic reactions to fibric acid derivatives are suspected.

Anisakis simplex-sensitized patients: should fish be excluded from their diet?

BACKGROUND

Anisakis simplex (A.s.) allergy is an emerging disease. The third-stage larvae of this nematode are a source of hidden allergens in fish. There are no clear guidelines concerning dietary restrictions for patients with serum-specific IgE to this parasite.

OBJECTIVE

To follow up the clinical data and immunological parameters of patients sensitized to A.s. during 6 to 23 months.

METHODS

The clinical symptoms and serologic status of 17 patients with specific IgE and positive skin prick test results to A.s. were studied prospectively. Six of these had anaphylaxis (ANA) attributed to A.s. and 11 patients experienced concomitant chronic urticaria (CU). All patients were advised not to eat fish for 6 months.

RESULTS

Four patients from the ANA group excluded fish, and ANA did not recur. Two other patients with ANA refused to exclude fish; one remained free of symptoms and the other experienced several urticarial episodes. During this 6-month period total IgE levels decreased in all six ANA patients; specific IgE for A.s. decreased in four patients and increased in two. Two patients from the CU group did not exclude fish, and symptoms persisted in these two patients. Clinical improvement was observed in 78% of the patients with CU who excluded fish. Total and specific IgE levels decreased in all the patients with CU.

CONCLUSIONS

Because ANA symptoms are very severe, patients should always be advised to exclude fish until specific food allergens are identified. However, in patients with CU and specific IgE to A.s., only the clinical response to fish ingestion will determine the need for strict fish avoidance.

DNA-based immunotherapeutics for the treatment of allergic disease

Allergic diseases are a growing health concern in industrialized countries. Despite a number of effective therapeutic options for the prevention and treatment of the pathophysiologic responses which characterize allergic diseases, the induction of true allergen desensitization remains an elusive therapeutic goal. Only immunotherapy (IT) has been shown to have any effect on the underlying hypersensitivities which mediate allergic reactions, and traditional protein-based allergen IT has a limited scope of efficacy However, a number of reagents collectively termed DNA-based immunotherapeutics have proven highly effective in both the prevention and reversal of Th2-mediated hypersensitivity states in mouse models of allergic disease. Four basic DNA-based immunotherapeutic modalities have been used for these studies. These include immunization with gene vaccines, allergen mixed with immunostimulatory oligodeoxynucleotide (ISS-ODN), and physical allergen-ISS-ODN conjugates (AIC), as well as immunomodulation with ISS-ODN alone. Results from many laboratories have generated guarded optimism that DNA-based immunotherapeutics may be effective for the reversal of allergic hypersensitivity states in humans, and several clinical trials have already been initiated. This review will focus on our present understanding of the biological activities of DNA-based immunotherapeutics and their application to the treatment of allergic diseases.

Allergy to an occupational allergen (Sapelli wood) in a child

The case is presented of a child who developed rhinoconjunctivitis, angioedema and asthma by sensitization to Sapelli wood, which was used in his father's carpentry. Positive skin-prick test, high levels of specific immunoglobulin E by ELISA and a positive conjunctival challenge test suggest a type I hypersensitivity mechanism to this wood. This is the first case report of sensitization to Sapelli wood and it confirms that occupational allergen exposure as Sapelli wood may also cause sensitization in a child.

Fluorescein-induced allergic reaction

BACKGROUND

Adverse reactions following intravenous sodium fluorescein are very unusual and their mechanism is still uncertain. We report the case of a patient who suffered an adverse reaction during a fluorescein ocular angiography. Positive allergy tests to fluorescein suggest an IgE-mediated mechanism.

OBJECTIVE

Report the allergy evaluation performed in a patient who suffered an adverse reaction during an intravenous fluorescein administration.

METHODS

We selected the case of a patient who suffered dizziness, diaphoresis, generalized pallor, nausea, sphincter relaxation, hypotension, and intense malaise during a fluorescein ocular angiography and compared the results to other nonreactive subjects. Allergy evaluation: Prick and intradermal skin tests and serial determinations of serum tryptase were performed on the patient and four control subjects who underwent and tolerated the same procedure as well as on a patient who developed an intense vagal reaction during blood extraction.

RESULTS

Positive skin tests and dramatic increase of serum tryptase (67U/I) were observed in our patient. The rest of the patients had negative skin tests and did not have any variation in their serum tryptase.

CONCLUSIONS

An IgE-mediated mechanism is suggested as responsible for this adverse reaction. We recommend that a complete allergy evaluation should be performed in all patients who have adverse reactions to fluorescein in order to differentiate true allergic reactions from other types of reactions.

Fixed drug eruption induced by indapamide. Cross-reactivity with sulfonamides

Indapamide is a nontiazidic sulfonamide diuretic which has not been previously reported as a cause of fixed drug eruption. We describe a patient who experienced several episodes of fixed drug eruption during treatment with indapamide. The diagnosis was confirmed by positive controlled oral challenge test. The possible existence of cross-reactivity with other sulfonamide derivatives was investigated by controlled oral challenge test with sulfamethoxazole, sulfadiazine and furosemide, with the tests with sulfamethoxazole and sulfadiazine resulting positive.

Acute IgE-mediated generalized urticaria-angioedema after topical application of povidone-iodine

Povidone is a synthetic polymer mainly used as a dispersing or suspending agent for many pharmaceutical products. It is also used as a carrier for iodine. In many countries it is not mandatory its inclusion in drug labels so many adverse effects may be under diagnosed. Povidone-iodine used as a topical antiseptic solution may produce allergic contact dermatitis and irritation. Povidone, when systemically administered may deposit in tissues causing local lesions and pain. Three cases of immediate hypersensitivity to this agent have been reported. We present a patient who developed generalized urticaria and angioedema immediately after the first topical use of Betadine (povidone-iodine) on a right arm wound. The positive skin prick test to Betadine and povidone extract and the demonstration of serum specific IgE to povidone, confirmed an IgE-mediated hypersensitivity.

Serum tryptase levels in adverse drug reactions

We evaluated the usefulness of individual tryptase levels and variations after adverse drug reactions in 64 patients. Our aim was to find a tool for the diagnosis of drug allergy. Thirty-seven subjects were confirmed to have drug allergy, 12 had nonsteroidal anti-inflammatory drug (NSAID) reactions, five had negative controlled drug challenges (NAAR), and 10 had symptoms after placebo intake (PLA). Serum tryptase levels greatly increased after anaphylactic shocks (2242%) and anaphylaxis (710.5%). Patients with allergic urticaria and those with idiosyncratic responses to acetylsalicylic acid (ASA) exhibited a small increase in serum tryptase (49.5% and 38.2%, respectively). In the other two groups (NAAR and PLA), no variation in this serum protease was observed. The time of appearance of the serum tryptase peak differed considerably among patients with similar clinical reactions (from 30 min to 6 h) and was independent of the latent period, severity of symptoms, or the amount of tryptase released. We conclude that serum tryptase determinations are helpful in the diagnosis of anaphylactic shock and anaphylaxis, but serial measurements may be needed to confirm mast-cell participation in milder reactions.

Recurrent fixed drug eruption caused by citiolone

Citiolone (N-acetylhomocysteinethiolactone) is a thiolic-derived medication frequently used in Spain and in other countries as a mucolytic agent for the treatment of certain hepatic disorders. Mucolytic drugs have rarely been implicated in the fixed drug eruption etiology. We report on a patient who presented several episodes of fixed exanthema related to citiolone intake. The patch test with citiolone (10% in dimethyl sulfoxide) was negative. The diagnosis was confirmed by a positive controlled oral challenge test. Other mucolytic thiolic-derivatives (N-acetylcysteine) were tolerated by the patient, thus crossreactivity between these drugs seems to be unlikely.

Murine eosinophils and IL-1: alpha IL-1 mRNA detection by in situ hybridization. Production and release of IL-1 from peritoneal eosinophils

The presence of IL-1 mRNA in eosinophils from mice infected with larvae of the parasite Mesocestoides corti was investigated by in situ hybridization technique. S35 labeled cDNA probe for alpha IL-1, hybridized with mRNA in murine eosinophils and macrophages. After 6 h of LPS stimulation eosinophils were able to express mRNA in their cytoplasm. This expression was highly increased by the addition of indomethacine. The IL-1 mRNA expression in murine macrophages was higher than in eosinophils in LPS-stimulated cells. This difference was statistically significant, p less than 0.001. To test if eosinophils may produce and release IL-1 in the culture medium, we isolated these cells in a Percoll gradient. Cell preparations with a purity exceeding 94% were cultured with various stimuli and their supernatants were tested for IL-1 activity. Eosinophils produced 169.65 +/- 73 U/ml when stimulated with LPS (n = 14). A dose-dependent response was obtained when the eosinophils were in the presence of the calcium ionophore A23187. Controls were performed to rule out the contribution of the contaminating population on the thymocyte proliferating activity. They were also used to detect other possible causes of interference in the assay, such as leukotrienes or TNF. IL-1 in supernatants was also detected using a conversion assay such as EL-4 thymoma cells. IL-1 activity was first detected in culture supernatants 18 h later, maximal production being in the first 24 h. In accordance with our hybridization results, an increase in IL-1 activity was obtained when eosinophils were stimulated with LPS and treated with indomethacine. The factor had a molecular mass between 16 to 20 kDa that corresponded to the described for murine IL-1. Inasmuch as IL-1 is an important mediator of inflammatory reactions this IL may enhance the proinflammatory action of eosinophils.

Murine eosinophils and IL-1: alpha IL-1 mRNA detection by in situ hybridization. Production and release of IL-1 from peritoneal eosinophils

The presence of IL-1 mRNA in eosinophils from mice infected with larvae of the parasite Mesocestoides corti was investigated by in situ hybridization technique. S35 labeled cDNA probe for alpha IL-1, hybridized with mRNA in murine eosinophils and macrophages. After 6 h of LPS stimulation eosinophils were able to express mRNA in their cytoplasm. This expression was highly increased by the addition of indomethacine. The IL-1 mRNA expression in murine macrophages was higher than in eosinophils in LPS-stimulated cells. This difference was statistically significant, p less than 0.001. To test if eosinophils may produce and release IL-1 in the culture medium, we isolated these cells in a Percoll gradient. Cell preparations with a purity exceeding 94% were cultured with various stimuli and their supernatants were tested for IL-1 activity. Eosinophils produced 169.65 +/- 73 U/ml when stimulated with LPS (n = 14). A dose-dependent response was obtained when the eosinophils were in the presence of the calcium ionophore A23187. Controls were performed to rule out the contribution of the contaminating population on the thymocyte proliferating activity. They were also used to detect other possible causes of interference in the assay, such as leukotrienes or TNF. IL-1 in supernatants was also detected using a conversion assay such as EL-4 thymoma cells. IL-1 activity was first detected in culture supernatants 18 h later, maximal production being in the first 24 h. In accordance with our hybridization results, an increase in IL-1 activity was obtained when eosinophils were stimulated with LPS and treated with indomethacine. The factor had a molecular mass between 16 to 20 kDa that corresponded to the described for murine IL-1. Inasmuch as IL-1 is an important mediator of inflammatory reactions this IL may enhance the proinflammatory action of eosinophils.