Hymenoptera Allergy Diagnosis through Their Presence on Human Food

Venom immunotherapy (VIT) protects up to 98% of treated Hymenoptera allergy patients from reactions with new stings. A correct diagnosis with the identification of the venom causing the allergic reaction is essential to implementing it. The knowledge of the Hymenoptera foraging habits when the sting takes place in a food environment would allow the culprit insect to be known. Images of Hymenoptera occurring in environments where there was human food were recorded in Spain, including the date of the image, the place description and its geolocation. The insects' genus and species were identified by an entomologist. Results: One hundred and fifty-five images depicting 71 insects were analyzed. The identified insects were Vespula (56), Vespa (7), Polistes (4), Cerceris (2), Bombus (1) and Apis (1). Most (97.1%) of the images were obtained in summer and early autumn, outdoors in terraces (64%). Meat was the food associated with 47.9% of the images. In protein-rich foods, Vespula was found in 89%. Conclusions: Vespula was the main Hymenoptera associated with food environments in our country (78.87%), and in most of the cases (71%), the food involved is a source of protein, such as meat or seafood. In that environment, the probability that the insect is a Vespula would be 89%.

Galactose-α-1,3-galactose (alpha-gal) allergy: first pediatric case in a series of patients in Spain

INTRODUCTION AND OBJECTIVES

Allergy to galactose-α-1,3-galactose (alpha-gal) is a peculiar form of food allergy generally manifesting as an anaphylactic reaction hours after mammalian meat consumption, due to the presence of specific IgE against this oligosaccharide. In addition, immediate anaphylaxis may develop after exposure to other sources of alpha-gal, such as monoclonal antibody cetuximab, vaccines, plasma expanders or anti-snake venoms. Sensitization to alpha-gal has also been implicated in the rapid degeneration of biological valve implants, and recognized as a cause of occupational disease in cattle raisers. The implication of tick bites in this type of sensitization has been accepted by all the research groups dedicated to this disease.

PATIENTS AND METHOD

The present study describes the clinical and sensitization characteristics of 39 patients diagnosed with alpha-gal allergy in the hospitals of our province (Lugo, Monforte de Lemos and Burela, Spain).

RESULTS

Most patients were middle-age males. Of note, is the fact that the series includes the first pediatric patient reported in Spain to date. The predominant clinical manifestations were urticaria or delayed anaphylaxis after consumption of mammalian meat. Seventy-four percent of the patients reported having suffered a previous tick bite, and the clinical presentation of anaphylaxis was significantly more prevalent in those with a persistent local reaction following the bite than in those with no such reaction (p = 0.032).

CONCLUSIONS

A review is also made of the disorder which, due to its variable clinical expression, is referred to as alpha-gal syndrome. The study concludes that a diagnosis of alpha-gal allergy should be considered in patients with urticaria-anaphylaxis of uncertain origin or manifesting after the administration of vaccines or products of bovine/porcine origin.

A Simple Score for Future Risk Prediction in Patients with Controlled Asthma Who Undergo a Guidelines-Based Step-Down Strategy

BACKGROUND

The minimum controlling dose of treatment must be established in patients with asthma, but the outcome of step-down is unpredictable.

OBJECTIVE

To identify factors associated with risk of control loss when stepping down asthma treatment and to develop a score to predict this risk.

METHODS

A prospective, multicenter study including adults with well-controlled asthma was performed. Treatment was stepped up or stepped down over a 12-month period to maintain asthma control. We determined associations between clinical and functional variables and step-down failure. Finally, we derived a score to predict loss of control in 1 cohort and validated it in an independent cohort.

RESULTS

The derivation cohort consisted of 228 patients; 218 completed at least 1 step-down episode and a total of 495 step-down episodes were evaluated. A medical-record documented postbronchodilator spirometry result of <70% forced expiratory volume in 1 second (FEV₁)/forced vital capacity (odds ratio [OR] = 2.08; 95% confidence interval [CI]: 1.26-3.43), current FEV₁ < 80% (OR = 1.80; 95% CI: 1.03-3.14), ≥1 severe exacerbation in the previous 12 months (OR = 2.43; 95% CI: 1.48-4.01), and Asthma Control Test score < 25 (OR = 2.30; 95% CI: 1.35-3.92) were independently associated with failure. The score showed an area under the curve of 0.690 (95% CI: 0.633-0.747; P < .05) in the derivation cohort and 0.76 (95% CI: 0.643-0.882; P < .001) in a validation cohort of 114 patients. A score <4.5 implies a low risk of failure (<20%), whereas a score >8 implies a high risk (>40%).

CONCLUSION

This score can facilitate the prediction of step-down failure before medication taper in patients with well-controlled asthma.

Serum tryptase concentrations in beekeepers with and without Hymenoptera venom allergy

BACKGROUND

Increased tryptase concentrations are a risk marker for the severity of reactions to Hymenoptera stings or venom immunotherapy

OBJECTIVE

To investigate serum tryptase concentrations in beekeepers with and without Hymenoptera venom allergy (HVA).

METHODS

Serum tryptase concentrations were measured in adult patients with HVA (n = 91, 37 of whom were beekeepers), beekeepers without HVA (n = 152), and control individuals from the general adult population (n = 246).

RESULTS

Multivariate analyses revealed that serum tryptase levels were positively associated with beekeeping activities (P < .001) and HVA (P < .001). Tryptase levels were also positively associated with age (P < .001) and male'sex (P = .02), and negatively associated with alcoho consumption (P = .002).

CONCLUSIONS

Beekeeping and HVA are independently associated with increased concentrations of serum tryptase.

Postmarketing study for assessment of tolerability of a grass allergen immunotherapy tablet (GRAZAX) in patients with rhinitis or rhinoconjunctivitis

BACKGROUND AND OBJECTIVE

Many patients with grass pollen allergy in Spain have concomitant sensitization to other allergens such as profilin. Since this type of sensitization is more common in Mediterranean countries than in countries where most patients were enrolled in clinical trials on GRAZAX (Phleum pratense 75,000 SQ-T/2, 800 BAU, ALK), the aim of this study was to analyze tolerability to GRAZAX under clinical practice conditions in patients with grass pollen allergy.

METHODS

A total of 155 patients were enrolled consecutively in a prospective, open-label, observational study. Adverse reactions were recorded during the first month of treatment at 3 different timepoints: after the first dose, when patients were kept under observation for 30 minutes, and on days 15 and 30 after starting treatment

RESULTS

With the first dose, 117 adverse reactions were recorded in 63 patients (40.7%). The commonest reactions (>10% patients) were oral pruritus (25.2%) and throat irritation (24.5%). Ear pruritus was recorded in 7.7%. All reactions but 1 occurred within 30 minutes of administration and all were mild-to-moderate. At the end of treatment, the percentage of patients with adverse reactions had decreased significantly (21.3%). Most adverse reactions (95.2%) were mild-to-moderate and only 3 (1.4%) were severe. No serious adverse reactions were recorded.

CONCLUSION

GRAZAX seems to be well tolerated, and most reactions were mild-to-moderate. Many of these reactions occur with the first dose. Therefore, according to the Summary of Product Characteristics, the first dose has to be administered under medical supervision.

Follow-up of venom immunotherapy (VIT) based on conventional techniques and monitoring of immunoglobulin E to individual venom allergens

OBJECTIVES

To assess the efficacy of venom immunotherapy (VIT) and monitor changes in in vivo and in vitro test results after 5 years of treatment and subsequent follow-up. To study the profile of immunoglobulin (Ig) E to individual allergens prior to treatment and 1 year afterwards.

METHODS

We studied 562 patients with hymenoptera venom allergy (438 to bee, 124 to wasp), all of whom underwent immunotherapy with Apis or Vespula extract. The patients were followed up using conventional in vivo and in vitro tests, and in 51 cases, specific IgE against the main hymenoptera allergens was measured before starting and after 1 year of treatment.

RESULTS

Of the 387 patients who completed VLT, 130 sensitized to Apis and 68 to Vespula suffered spontaneous re-stings during treatment. Of these, 123 (94.6%) did not suffer any reaction and 64 (94.1%) suffered only a local reaction. Sixty-two patients sensitized to Apis and 14 sensitized to Vespula suffered spontaneous re-stings after stopping treatment. Only 3 patients suffered a systemic reaction (grade I Müller). At the end of treatment, the results of skin tests and specific IgE to whole extract improved significantly. Reductions in IgE to the main allergens were observed after 1 year of treatment (median differences in Ves v 5, -238.0, P = .0425; and in Api m 1, -183.0, P = .0024).

CONCLUSION

The high rate of spontaneous re-stings shows that efficacy is maintained for years after completing treatment in a real-world setting. Determination of IgE to individual venom allergens may offer new perspectives in the diagnosis and follow-up of these patients.

Exhaled nitric oxide predicts control in patients with difficult-to-treat asthma

We aimed to evaluate the accuracy of baseline exhaled nitric oxide fraction (F(eNO)) to recognise individuals with difficult-to-treat asthma who have the potential to achieve control with a guideline-based stepwise strategy. 102 consecutive patients with suboptimal asthma control underwent stepwise increase in the treatment with maximal fluticasone/salmeterol combination dose for 1 month. Then, those who remained uncontrolled received oral corticosteroids for an additional month. With this approach, 53 patients (52%) gained control. Those who achieved control were more likely to have positive skin results (60.4% versus 34%; p = 0.01), positive bronchodilator test (57.1% versus 35.8%; p = 0.02) and peak expiratory flow variability > or =20% (71.1% versus 49.1%; p = 0.04). Conversely, depression was more frequent in those who remained uncontrolled (18.4 % versus 43.4 %; p = 0.01). An F(eNO) value > or =30 ppb demonstrated a sensitivity of 87.5% (95% CI 73.9-94.5%) and a specificity of 90.6% (95% CI 79.7-95.9%) for the identification of responsive asthmatics. The current results suggest that F(eNO) can identify patients with difficult-to-treat asthma and the potential to respond to high doses of inhaled corticosteroids or systemic steroids.

Occupational respiratory allergy to roe deer

BACKGROUND

Although scattered reports have been published on roe deer allergenicity, no systematic studies of allergenicity or possible cross-reactions have appeared.

OBJECTIVES

To describe 2 patients with occupational roe deer allergy, demonstrated by positive skin and conjunctival provocation test results, and to note cross-reactions to other animal (mainly cow) allergens.

METHODS

Two workers at animal rehabilitation centers were sensitized to roe deer. One patient had a history of rhinoconjunctivitis and the other a history of rhinoconjunctivitis and probable asthma. Both patients underwent skin testing with a standard battery of inhaled and epithelial allergens and with roe deer hair and dander extract and conjunctival provocation tests with roe deer hair extract. Immunodetection for IgE (both patients) and IgE immunoblot inhibition tests to determine inhibitory effect (1 patient) were also performed.

RESULTS

The results of skin tests and conjunctival provocation tests showed that both patients were sensitized to roe deer allergens. In one patient specific IgE to roe deer extract was detected, and this extract completely inhibited IgE binding to cow hair and dander extract in immunoblotting tests. Specific IgE to roe deer proteins could not be demonstrated in the other patient.

CONCLUSIONS

Our results suggest that roe deer epidermal derivatives can cause occupational respiratory disease in exposed workers and that allergy to this species should be considered in individuals who present with similar symptoms and exposure histories. Immunoblot inhibition studies suggested the possibility of cross-reaction between roe deer proteins and cow proteins.

In vivo and in vitro allergenicity of the domestic mite Chortoglyphus arcuatus

BACKGROUND

Chortoglyphus arcuatus is frequently identified in mattress dust samples in coastal areas of northern Spain.

OBJECTIVES

To establish the prevalence of positive skin test reactions to C. arcuatus and to analyze its allergenicity and cross-reactivity.

METHODS

One hundred thirty-eight consecutive patients entered the study. The main referred symptoms were rhinoconjunctivitis and asthma. Skin tests were performed with extracts of Dermatophagoides pteronyssinus, Lepidoglyphus destructor, Tyrophagus putrescentiae, C. arcuatus, and Glycyphagus domesticus. Enzyme-linked immunosorbent assay inhibition experiments were conducted with the different mite species and immunoblots with serum samples from 31 sensitized patients. Conjunctival provocation tests were performed in 10 patients with C. arcuatus-positive skin test reactions and in 9 with negative results; all the patients had positive skin test reactions to D. pteronyssinus.

RESULTS

The prevalence of positive skin test reactions to D. pteronyssinus was 94.2% and to C. arcuatus was 58%. There was a significant correlation between the number of mites to which patients were sensitized and the time of disease evolution (P = .02). Results of enzyme-linked immunosorbent assay inhibition experiments suggested minimal cross-reactivity between C. arcuatus and D. pteronyssinus. Immunoblot results confirmed specific IgE binding to several bands. Conjunctival test results were positive in 9 of 10 C. arcuatus-positive individuals and slightly positive in 2 of 9 C. arcuatus-negative, D. pteronyssinus-positive individuals.

CONCLUSIONS

There is a high prevalence of sensitization to C. arcuatus in northern Spain. Sensitization to this species should be considered of clinical significance. There is minimal cross-reactivity between C. arcuatus and D. pteronyssinus.

High efficacy and absence of severe systemic reactions after venom immunotherapy

The efficacy of immunotherapy with venom (ITV) is supported by many studies. However, the key point for ITV is the balance between safety and efficacy, as concern for adverse events may restrict its use, and limit the administration of this treatment to the hospital, exclusively. The objectives of the present study were, first, to analyze the characteristics and incidence of ITV-related adverse events and to determine whether the administration of this treatment exclusively in hospitals is justified, and second, to assess the efficacy of a semi-rush dosage schedule, which is being used in our department. We analyzed the data of 241 patients with known allergy to hymenoptera venom (208 sensitive to Apis mellifera and 33 to Vespula spp.), who were treated with ITV (Pharmalgen, ALK-ABELLO) for an average period of 32 months. The initial treatment was performed at the Allergy Department, administering nine increasing doses of the venom once or twice a week. Maintenance treatment, whenever possible, was performed at primary care centers (PCCs). In this study, 95 patients (39%) were referred to their corresponding PCC. A total of 3697 doses were administered, and 37 systemic reactions (SR) and 37 local reactions (LR) were recorded; the overall frequency of occurrence of adverse events was 1.97%, 1% corresponding to SR, and 1% related to LR. The severity of most of SR was mild and the response to treatment with oral antihistamines and corticoids was good. Administration of adrenaline was required in 14 cases. Regarding the maintenance treatment administered at PCCs, only two adverse events were recorded, one case of vaso-vagal symptomatology and one case of urticaria-like reaction two hours after the administration. Eighty-four cases of spontaneous field stings, corresponding to 58 patients, were reported; in 82 cases (97.6%) the reaction was less severe than that experienced before the administration of ITV. The severity of the other two reactions was the same as previously recorded, though they occurred in patients during the build-up phase of the treatment. In any case, a reaction with a higher grade of severity was recorded. The dosage schedule administered is efficient, the frequency of occurrence of adverse events is low, their intensity is generally mild, and minimum medication is required to control them (antihistamines, corticosteroids). Taking into account the tolerance observed during the maintenance treatment, we consider that its administration at PCCs is appropriate.

Assessment of profilin as an allergen for latex-sensitized patients

BACKGROUND

The presence of the actin-binding protein, profilin, has been demonstrated in natural latex extracts; but the clinical significance of this molecule as an allergen for latex-allergic patients is not clear. We studied the allergenic relevance of isolated latex natural and recombinant profilin, by in vivo and in vitro techniques, in two populations of spina bifida children (SB) and adults allergic to latex (AL).

METHODS

Profilin is present in small amounts in latex extracts obtained from low ammoniated (LA) natural latex. Its purification by affinity chromatography resulted difficult due to Heb v 1 unspecific binding. Therefore a method was developed to obtain natural profilin from natural latex, combining affinity chromatography (PLP, poly-L-proline Sepharose column) and previous ammonium sulfate fractionation. Alternatively, latex c-serum containing a low amount of Hev b 1 and a relatively higher profilin content could be used. Recombinant latex profilin isoform (rHev b 8) was cloned by PCR amplification. The entire coding region of Hev b 8 was subcloned into the expression vector pKN172 and a non-fusion form of Hev b 8 was expressed in Escherichia coli BL21 (DE3). Purified recombinant protein was obtained after a single passage through PLP-Sepharose column.

RESULTS

Natural and recombinant purified Hev b 8 were tested cutaneously by intradermoreaction (ID) in 17 SB and 14 AL patients. They were positive in 15 SB and 14 AL patients. No wheals were produced when tested in nonatopic control patients. Only 42% of sera from latex-allergic patients revealed specific IgE titers of class 1 or higher by enzyme immunoassay and only 39% of them exhibited IgE binding by SDS-PAGE immunoblotting with any natural or recombinant Hev b 8 forms.

CONCLUSION

It seems that profilin is a relevant allergen for both groups of patients from a frequency point of view, but with scarce presence in natural latex extracts and raw sources, with a subsequent low IgE induction capacity.

[Childhood asthma and viral infection: interactions and therapeutic possibilities]

Rhinovirus infections are the main cause of wheezing in children and adults. Studies carried out with experimental infections report that at least in certain conditions, this infection may spread to the lower respiratory tract as the virus acts on the respiratory epithelium. In vitro experiments with cells from the immune system and lower respiratory tract suggest that the mechanisms of action are directly linked to the production of pro-inflammatory cytokines. Both in vivo and in vitro evidence shows that rhinoviruses may stimulate bronchial epithelial cells to produce cytokines and pro-inflammatory chemokines. They may also stimulate the cholinergic and non-cholinergic nervous system, increasing the production of ICAM-1 and may give rise to a T-lymphocyte non-specific response or to T-lymphocyte replication in direct relation with viral infection. In addition, greater production of cysteinyl leukotrienes has been observed in the secretions of patients with bronchospasm. Experimental infection with Rhinovirus increases clinical symptomatology and bronchial hyperreactivity. The latter is associated with increased eosinophils and cationic proteins in sputum. The above findings suggest that multiple cellular pathways are involved in the induction of exacerbations of asthma induced by the virus. In addition, the possible stimulating role of exposure to allergens in sensitized patients would also increase allergic inflammation. Because of the limited therapeutic efficacy of steroids in reducing exacerbations, new treatment strategies based on greater insight into the physiopathology of the role of viruses in asthma are needed.

Factors influencing the clinical picture and the differential sensitization to house dust mites and storage mites

Sensitization to house dust mites and storage mites has been studied in a number of papers, but several environmental factors and clinical conditions that differently affect sensitization to these mites are still controversial. The purpose of this study was to determine the influence of climatic conditions, occupation and patient age in the differential sensitization to house dust and storage mites, and also to search for possible different symptoms caused by each group of mites. Eighty patients sensitized to mites but not to other inhalant allergens were studied by case history and by skin prick test and serum IgE to Dermatophagoides pteronyssinus. Dermatophagoides farinae, Lepidoglyphus destructor and Tyrophagus putrescentiae. Home conditions, including content of the allergens Der p 1, Der f 1, Lep d 2 and Tp, were determined for all patients. Human activities, such as farming or similar occupations, and humidity are conditions for preferential sensitization to storage mites, while we found no difference between living in rural or urban areas. Mean age for the onset of sensitization was 6.7 years for house dust mites and 18.7 years for storage mites. Conjunctivitis was more frequent in patients allergic to storage mites, whereas perioral syndrome (itching of the tongue and swelling of the lips) was only seen in patients sensitized to T. putrescentiae. We concluded that climatic and damp conditions and human activity, but not urban or rural living environments, influence the differential sensitization to house dust mites and storage mites.

[Preventive immunotherapy]

Allergen specific immunotherapy has been shown to be effective in rigorous double-blind placebo-controlled clinical trials in both children and adults A recent WHO position paper stated that immunotherapy is an effective treatment for patients with allergic rhinitis/conjunctivitis, allergic asthma and allergic reactions from stinging insects and is thought to be more effective in children than in adults. When speaking about children there are several questions that are important regarding the natural course of the disease. One of the most important is whether immunotherapy can prevent asthma, either by preventing sensitisation to allergens related to the development of asthma or by preventing the inflammation in the lungs caused by allergen exposure. Another point could be to establish the differences in the long term outcome of those patients treated with immunotherapy and medication during childhood, compared to the long term outcome of those with comparable asthma features who received only antiasthmatic medication The PAT study is a European multi-center study. The end-point is to show in what capacity allergen specific subcutaneous immunotherapy can prevent the development of asthma in children who only have rhinoconjunctivitis secondary to grass or birch pollen sensitisation. Two hundred and ten children aged from 5 to 13 years were included in the study. Children were randomised to the active treatment group receiving allergen specific immunotherapy with birch and/or timothy pollen allergen extract or to the control group receiving only pharmacotherapy. It is important to highlight that the main criteria to be included was that the children should never have had any asthmatic symptom. Immunotherapy has been effective in terms of decreasing significantly the amount of symptoms in the active group compared to the control one. It was safe with no serious adverse reactions and reduced the risk of the onset of asthma. After two years of treatment more children in the control group developed clinical asthma than in the active group: p = 0.004. Des Roches et al reported the results of a prospective non randomised trial of immunotherapy with Dermatophagoides pteronyssinus in 44 asthmatic children younger than six years of age who were sensitive only to dust mites. The purpose of the study was to assess whether immunotherapy could reduce the development of new sensitisation during a period of three years of follow up. Specific immunotherapy was given with only D. Pteronyssinus extract. All 22 children in the control group developed new sensitivities as determined by skin testing and in vitro tests, while 10 (45%) of 22 children who received mite immunotherapy did not develop additional sensitivities. The findings of this study suggests that immunotherapy may alter the natural course of the allergic sensitisation reducing the risk of developing new sensitisation in mono sensitive children. A limited number of studies have examined the long terms effects of immunotherapy on the clinical presentation of asthma and rhinoconjunctivitis, and have shown a long lasting efficacy decreasing the amount of symptoms 6-10 years after termination. In a retrospective study of children treated with immunotherapy during childhood for at least three years, that were re-evaluated in early adulthood, the control patients who were treated with medication and no immunotherapy suffered almost 3.5 times more symptoms than the active group treated with immunotherapy. The current findings suggest that immunotherapy should be considered earlier in the course of allergic disease to prevent progression or to prevent the development of new sensitisation. Further studies with long term follow up particularly in children could address this possibility.