Clinical management of plant food allergy in patients sensitized to lipid transfer proteins is heterogeneous: identifying the gaps

BACKGROUND AND OBJECTIVE

Patients sensitized to lipid transfer protein (LTP) present a wide clinical variability. The lack of practical diagnostic and therapeutic guidelines complicate their management. The aim of the study was to describe the clinical approach of Spanish allergists to this pathology using a survey designed by PICO method and subsequent Delphi approach validation.

METHODS

Designed survey was answered by 224 allergists (75% women; 57.1% with >20 years of professional experience). Homogeneity regarding clinical practice on the main points of LTP allergy diagnosis was observed, except for patients with suspected NSAID hypersensitivity (44.6% frequently include LTP skin testing). Oral food challenges were not frequently performed (63.6% occasionally to never), and they were generally (75.5%) used to confirm tolerance. It was common to recommend fruit skins avoidance (77.2%) and maintaining consumption of foods to which patients are sensitised but tolerant (99.1%).

RESULTS

There was heterogeneity on other dietary indications, modifications due to co-factors, or traces avoidance. Peach sublingual immunotherapy (SLIT) was considered very/quite effective by 55.9% of allergists. The majority (79.5%) consider SLIT indicated in <25% of LTP allergic patients, based on severity (95.2%), frequency of reactions (99.4%), allergy to multiple food families (97.4%), and the quality of life/nutrition impairment (91.5%). There was different practice on SLIT prescription based on co-factor involvement.

CONCLUSION

These data suggest that there is a need to increase evidence to reduce the clinical practice heterogeneity in the management of LTP allergy.

Food-Induced Anaphylaxis: Data From the European Anaphylaxis Registry

BACKGROUND

Food is one of the most common elicitors of anaphylaxis, with an increasing incidence over recent years.

OBJECTIVES

To characterize elicitor-specific phenotypes and identify factors enhancing the risk or severity of food-induced anaphylaxis (FIA).

METHODS

We analyzed data from the European Anaphylaxis Registry applying an age- and sex-matched analysis of associations (Cramer's V) for single food triggers and calculated odds ratios (ORs) for severe FIA.

RESULTS

We identified 3,427 cases of confirmed FIA showing an age-dependent elicitor ranking (for children: peanut, cow's milk, cashew, and hen's egg; and for adults: wheat flour, shellfish, hazelnut, and soy). The age- and sex-matched analysis revealed defined symptom patterns for wheat and cashew. Wheat-induced anaphylaxis was more frequently associated with cardiovascular symptoms (75.7%; Cramer's V = 0.28) and cashew-induced anaphylaxis with gastrointestinal symptoms (73.9%; Cramer's V = 0.20). Furthermore, concomitant atopic dermatitis was slightly associated with anaphylaxis to hen's egg (Cramer's V = 0.19) and exercise was strongly associated with anaphylaxis to wheat (Cramer's V = 0.56). Additional factors influencing the severity were alcohol intake in wheat anaphylaxis (OR = 3.23; CI, 1.31-8.83) and exercise in peanut anaphylaxis (OR = 1.78; CI, 1.09-2.95).

CONCLUSIONS

Our data show that FIA is age-dependent. In adults, the range of elicitors inducing FIA is broader. For some elicitors, the severity of FIA seems to be related to the elicitor. These data require confirmation in future studies considering a clear differentiation between augmentation and risk factors in FIA.

Validation of novel recipes for masking peanuts in double-blind, placebo-controlled food challenges

BACKGROUND

Double-blind, placebo-controlled oral food challenges are the gold standard in food allergy diagnosis. Nevertheless, proper masking of peanuts is particularly complex owing to their intense flavor and odor. Thus, it is important to use validated recipes to ensure their adequate masking during oral food challenges.

OBJECTIVE

To design and validate recipes containing masked peanuts for double-blind, placebo-controlled oral food challenges.

METHODS

Two types of products (cookies and a custard‑type dessert) containing the masked peanuts and other ingredients with low allergenic potential were designed and validated. For this purpose, of the 24 initial cookie recipes and 12 initial custard recipes developed, those that did not exhibit significant differences in their texture were selected for sensory validation.

RESULTS

Similarity triangle tests were performed using a panel of 36 selected tasters, enabling the validation of 1 pair of cookie recipes and 1 pair of custard-type dessert recipe, both with low allergenic potential and suitable for those with celiac disease and for vegans.

CONCLUSION

The validated recipes are of clinical and research interest because they allow to confirm a peanut allergy and detect a wide range of tolerated threshold doses, which makes it possible to provide specific indications for each patient.

Onset of nut allergy in a pediatric cohort: clinical and molecular patterns. AFRUSEN study

Nut Allergy, Peanut, Walnut, Allergy Onset, Sensitization Profile, Component Resolved Diagnosis, Anaphylaxis, Food Allergy.

Wheat Anaphylaxis in Adults Differs from Reactions to Other Types of Food

BACKGROUND

Wheat is one of the most commonly consumed foods and a known elicitor of anaphylaxis in children and adults. Reactions in adults are often cofactor dependent and characterized by a prolonged time between food intake and the onset of symptoms making the diagnosis of wheat anaphylaxis challenging.

OBJECTIVE

To characterize a cohort of patients with the history of wheat anaphylaxis to better understand this atypical phenotype of anaphylaxis.

METHODS

Data from the European Anaphylaxis Registry from 2007 to 2019 (n = 10,636) including 250 patients (213 adults and 37 children) with a history of anaphylaxis caused by wheat were analyzed.

RESULTS

Wheat was the most common food elicitor of anaphylaxis in adults in the registry in Central Europe. Reactions to wheat in adults were frequently associated with exercise as a cofactor (82.8%) and partially delayed (57.5%). Only 36.9% of patients had atopic comorbidities, which was uncommonly low for adult patients allergic to other kinds of foods (63.2%). Anaphylaxis to wheat presented frequently with cardiovascular symptoms (86.7%) including severe symptoms such as loss of consciousness (41%) and less often with respiratory symptoms (53.6%). The reactions to wheat were more severe than reactions to other foods (odds ratio [OR] = 4.33), venom (OR = 1.58), or drugs (OR = 2.11).

CONCLUSIONS

Wheat is a relevant elicitor of anaphylaxis in adults in Central Europe. Wheat anaphylaxis is highly dependent on the presence of cofactors and less frequently associated with atopic diseases compared with other food allergies. More data on mechanisms of wheat-induced anaphylaxis are required to develop preventive measures for this potentially life-threatening disease.

Risk Factors and Characteristics of Biphasic Anaphylaxis

BACKGROUND

Anaphylaxis is an immediate hypersensitivity reaction. However, a biphasic course with the second onset of symptoms can occur hours after the initial phase. Little is known about the causes of biphasic anaphylaxis making the identification of patients at risk difficult.

OBJECTIVE

To identify factors predisposing for biphasic anaphylaxis for the better understanding of these reactions.

METHODS

Data from the Anaphylaxis Registry (from 11 countries) including 8736 patients with monophasic and 435 biphasic anaphylaxis were analyzed.

RESULTS

The rate of biphasic reactions in this large cohort was 4.7%. The identified risk factors were reaction severity (grade III/IV vs grade II: odds ratio [OR] = 1.34; 95% confidence interval [CI]: 1.1-1.62); multiorgan involvement; skin, gastrointestinal, severe respiratory, and cardiac symptoms; anaphylaxis caused by peanut/tree nut (OR = 1.78; 95% CI: 1.38-2.23) or an unknown elicitor (OR = 1.96; 95% CI: 1.41-2.72); exercise as a cofactor (OR = 1.44; 95% CI: 1.17-1.78); chronic urticaria as a comorbidity (OR = 2.12; 95% CI: 1.19-3.78); a prolonged interval between the contact with the elicitor and start of primary symptoms (OR for >30 vs <30 min: 1.38; 95% CI: 1.08-1.76); and antihistamine treatment (OR = 1.52; 95% CI: 1.14-2.02).

CONCLUSION

A biphasic course of anaphylaxis occurs more frequently in severely affected patients with multiorgan involvement. However, we identified multiple additional predictors, suggesting that the pathogenesis of biphasic reactions is more complex than being a rebound of a severe primary reaction.

Refractory Anaphylaxis: Data From the European Anaphylaxis Registry

Refractory anaphylaxis (unresponsive to treatment with at least two doses of minimum 300 μg adrenaline) is a rare and often fatal hypersensitivity reaction. Comprehensive data on its definition, prevalence, and risk factors are missing. Using the data from the European Anaphylaxis Registry (11,596 cases in total) we identified refractory anaphylaxis cases (n = 42) and analyzed these in comparison to a control group of severe anaphylaxis cases (n = 4,820). The data show that drugs more frequently elicited refractory anaphylaxis (50% of cases, p < 0.0001) compared to other severe anaphylaxis cases (19.7%). Cases elicited by insects (n = 8) were more often due to bees than wasps in refractory cases (62.5 vs. 19.4%, p = 0.009). The refractory cases occurred mostly in a perioperative setting (45.2 vs. 9.05, p < 0.0001). Intramuscular adrenaline (as a first line therapy) was administered in 16.7% of refractory cases, whereas in 83.3% of cases it was applied intravenously (significantly more often than in severe anaphylaxis cases: 12.3%, p < 0.0001). Second line treatment options (e.g., vasopression with dopamine, methylene blue, glucagon) were not used at all for the treatment of refractory cases. The mortality rate in refractory anaphylaxis was significantly higher (26.2%) than in severe cases (0.353%, p < 0.0001). Refractory anaphylaxis is associated with drug-induced anaphylaxis in particular if allergens are given intravenously. Although physicians frequently use adrenaline in cases of perioperative anaphylaxis, not all patients are responding to treatment. Whether a delay in recognition of anaphylaxis is responsible for the refractory case or whether these cases are due to an overflow with mast cell activating substances—requires further studies. Reasons for the low use of second-line medication (i.e., methylene blue or dopamine) in refractory cases are unknown, but their use might improve the outcome of severe refractory anaphylaxis cases.

Lipid Transfer Protein Syndrome in a Non-Mediterranean Area

BACKGROUND

Plant food allergies associated with lipid transfer protein (LTP) have been widely described in the Mediterranean Basin.

OBJECTIVE

The aim of this work was to describe the clinical profile and pollen sensitization of plant food- allergic patients sensitized to LTP in a non-Mediterranean area.

METHODS

Patients with clear IgE-mediated symptoms associated with plant foods and a positive skin prick test (SPT) to Pru p 3 were included in a prospective study in the north of Spain. Reported symptoms were analyzed together with a battery of food and pollen SPTs and specific IgE components by ISAC microarray. Cross-inhibition studies were performed by ImmunoCAP with plane tree, mugwort and rPru p 3.

RESULTS

Among the 72 patients included, the most frequent food allergy reported was to peaches (69%) followed by nuts (walnuts 55%, peanuts 54% and hazelnuts 43%). Most patients suffered from symptoms with multiple plant foods (a median of 6 foods per patient). Regarding the patients' pollen sensitization, 36% were sensitized to mugwort pollen (72% showing sIgE to Art v 3), 33% to grass pollen and 24% to plane tree pollen (94% with sIgE to Pla a 3). Inhibition studies showed that specific IgEs against mugwort and plane tree pollen are inhibited by Pru p 3 in a strong manner, whereas Pru p 3 was less inhibited by pollen extracts.

CONCLUSIONS

LTP syndrome occurs in a non-Mediterranean area and is related to multiple sensitizations to foods and pollens such as plane tree and mugwort. In these pollen sensitizations, Pru p 3 seems to be the primary sensitizer.

Optimal duration of allergen immunotherapy in children with dust mite respiratory allergy

BACKGROUND

Subcutaneous immunotherapy (SCIT) discontinuation data in children remain scarce.

OBJECTIVE

We sought for differences in the clinical efficacy of 3 vs. 5 yr of SCIT in children with dust mite respiratory allergy.

METHODS

We performed a 5-yr, phase IV prospective study. After the first year, the patients were randomized to 3 (IT3) or 5 yr of treatment (IT5). Efficacy was assessed at 3rd and 5th year by symptom and medication scores and visual analog scales (VAS). Skin tests with common allergens and in vitro assessments were also performed.

RESULTS

Eighty-one children (mean age: 9 yr) were randomly assigned to 3 (IT3: 41) or 5 yr (IT5: 40) of immunotherapy. After 3 years, rhinitis global scores decreased in IT3 (44%; p = 0.002) and in IT5 (50%; p = 0.001). Asthma global, symptom and medication scores decreased by 100% in IT3 (p = 0.001) and IT5 (p = 0.001). VAS scores also diminished significantly (IT3: 70%, p = 0.001; IT5: 62.5%; p = 0.001). At 5th year, global rhinitis scores were reduced an additional 30% in IT5 children. Comparisons between both groups did not show differences in rhinitis (p = 0.055), asthma global scores (p = 0.948) or VAS scores at 5th year. Twenty percent of IT5 (p = 0.002) and 7% of IT3 children (p = 0.705) developed new sensitizations. At 5th year, sIgG4 determinations decreased in IT3 without significant variations in IT5.

CONCLUSIONS

Three years of SCIT induced significant improvement in children with dust mite respiratory allergy, but a 5-yr course added clinical improvement in rhinitis.

Are basophil activation and sulphidoleukotriene determination useful tests for monitoring patients with peach allergy receiving sublingual immunotherapy with a Pru p 3-enriched peach extract?

INTRODUCTION

Treatment of food allergy essentially consists of food avoidance, but immunotherapy with food is emerging as a new therapeutic option.

OBJECTIVE

To evaluate clinical improvement and immunological changes in patients with peach allergy following sublingual immunotherapy (SLIT) with a Prup3 quantified peach extract.

METHODS

A randomized, double-blind, placebo-controlled clinical trial with peach SLIT was conducted. We assessed clinical efficacy after 6 months of treatment by means of double-blind, placebo-controlled oral challenges with peach and also evaluated immunological changes (basophil activation test [BAT] and determination of sulphidoleukotriene production) following stimulation with peach peel and pulp, rPrup3, rMald 1, and rMal d 4 stimulation. We also measured specific IgE and IgG4 to Pru p3.

RESULTS

After 6 months of SLIT (T6), the active group showed a 3-fold improvement in tolerance to Prup3 and a significant increase in IgE to rPrup3 and in sLT production following stimulation with peach peel and rPrup3. There was also a significant increase in BAT results after stimulation with rPrup3 at 1 month of SLIT (T1). Statistically significant between-group differences were only observed for BAT with peach peel and pulp at T1 and T6 and for BAT with rPru p3 at T6. No changes were observed in BAT with rMal d 1 or rMal d 4 or in IgG4 levels to nPrup3.

CONCLUSIONS

SLIT with a Pru p 3 quantified peach extract is clinically effective and leads to an increase in basophil activation and sulphidoleukotriene production following stimulation with rPru p3 and peach peel in the first months of treatment.

Recommendations for the use of in vitro methods to detect specific immunoglobulin E: are they comparable?

Total and specific immunoglobulin (Ig) E can be detected in vitro using several commercially available methods. The largest share of the global market for these methods is held by the ImmunoCAP technique (Thermo Fisher, previously Phadia), Immulite (Siemens), and Hytec-288 (Hycor). Most comparative studies examine Immulite and ImmunoCAP, which differ methodologically but use similar units of measurement relative to the same standard of total IgE (WHO IgE Standard 75/502). Despite their similarity, these kits differ in their quantification of specific IgE, which varies depending on the allergen studied.Thus, specific IgE results obtained with ImmunoCAP and Immulite are not interchangeable. It is important to bear this in mind, especially when determining cutoff points as predictors of a response to oral challenge with specific food allergens. The method used in practice must be the same as the one in the publication guiding clinical decision making. We analyze differences between ImmunoCAP and ISAC microarray, 2 methods from the same manufacturer used to detect IgE to specific proteins (purified or recombinant).The results show that the IgE values obtained with ImmunoCAP are not equivalent to the corresponding values obtained with the ISAC microarray system.

Three years of specific immunotherapy may be sufficient in house dust mite respiratory allergy

BACKGROUND

Specific immunotherapy (SIT) duration for respiratory allergy is currently based on individual decisions.

OBJECTIVE

To evaluate the differences in clinical efficacy of SIT as a result of the duration between the current recommended limits (3-5 years).

METHODS

A 5-year prospective, controlled clinical trial of SIT blind until the first year and randomization to a 3-year (IT3) or 5-year (IT5) course was conducted. Of the 239 patients with respiratory allergy caused by D pteronyssinus initially included, 142 completed 3 years of SIT with good compliance. Twenty-seven controls were included at the third year. Efficacy of SIT after 3 (T3) and 5 (T5) years was assessed by using clinical scores, visual analog scales (VASs), rhinitis (RQLQ) and asthma (AQLQ) quality of life questionnaires, skin tests, and serum immunoglobulins.

RESULTS

At T3, significant reductions were observed in rhinitis (44% in IT3 and 50% in IT5; P < .001), asthma (80.9 % in IT3 and 70.9% in IT5; P < .001) scores, VAS (P < .001 in both), RQLQ (P < .001 in both) and AQLQ (P < .001 in both). At T5, the clinical benefit was maintained in both groups, and IT5 patients presented additional decreases (19%; P = .019) in rhinitis scores. At Tf, specific IgG(4) measurements were lower in IT3 (P = .03) without detecting differences in IT5. An increase in asthma score of 133% was the only difference observed in controls.

CONCLUSION

Clinical improvement is obtained with 3 years of D pteronyssinus SIT. Two additional years of SIT add clinical benefit in rhinitis only.

Oleaceae-induced pollinosis in an area with exposure to olive and ash trees

BACKGROUND

Navarre, in Northern Spain, is an area with moderate exposure to olive and ash tree pollen.

OBJECTIVE

To assess the relevance of ash as a cause of pollinosis in our region.

METHODS

The study sample comprised 85 patients from Navarre with clinical symptoms of pollinosis. Specific immunoglobulin E (sIgE) was determined to Fra e 1, Ole e 1, and a mixture of amino- and carboxy-terminal domains of Ole e 9 (Ole e 9 NC) (ADVIA-Centaur). At the same time, the presence of sIgE to other pollen allergens was studied. Prick tests were performed with ash pollen (n=33) and olive pollen (n=85) and the symptomatic period was recorded (n=85). As a control group, we studied the serum of 98 patients with olive pollen allergy, intense exposure to olive pollen, and no exposure to ash.

RESULTS

Sensitization to Oleaceae was detected in 24/85 patients in the study group (28.2%). In this group, the mean (SD) level of IgE to Fra e 1 was 8.5 (10) kU(A)/L and to Ole e 16.07 (7.88) kU(A)/L (P < .001). In the control group, these figures were 103.64 (132.19) kU(A)/L and 86.43 (118.5) kU(A)/L (P < .001), respectively. In all patients with positive sIgE to Fra e 1, IgE to Ole e 1 was also detected (concordance index, kappa = 1), both in the study group and in the control group. Patients who were sensitized to Fra e 1 did not present a longer symptomatic period and their symptoms did not have an earlier onset.

CONCLUSION

We did not find evidence of clinically relevant sensitization to ash in Navarre.

Cross-reactivity syndromes in food allergy

The immunological phenomenon of cross-reactivity has consequences for the diagnosis and treatment of certain food allergies. Once allergy to a particular food has been confirmed, positive test results are often obtained against other foods and, although less frequently, true clinical cross-reactivity is determined. This article reviews the relevant clinical aspects of food allergies in which the underlying mechanism is cross-reactivity between foods that are both related and unrelated taxonomically.

Diagnosis and management of immunodeficiencies in adults by allergologists

Primary immunodeficiencies (PIDs) are genetic diseases that cause alterations in the immune response and occur with an increased rate of infection, allergy, autoimmune disorders, and cancer. They affect adults and children, and the diagnostic delay, morbidity, effect on quality of life, and socioeconomic impact are important. Therapy (gamma-globulin substitution in most cases) is highly effective. We examine adult PIDs and their clinical presentation and provide a sequential and directed framework for their diagnosis. Finally, we present a brief review of the most important adult PIDs, common variable immunodeficiency, including diagnosis, pathogenesis, clinical signs, and disease management.

In vitro diagnosis of immediate allergic reactions to drugs: an update

Evaluation of allergic reactions to drugs is difficult because of the poor sensitivity of in vivo tests, which makes controlled administration of the drug necessary to confirm the diagnosis. In vitro tests are important in order to avoid the risks of in vivo testing. In the present review, we describe the different methods for detecting immunoglobulin (Ig) E antibodies that are specific to drugs involved in the development of type I (immediate) reactions. The 2 main in vitro methods are immunoassays and the basophil activation test, both of which have sufficient sensitivity and specificity for the detection of specific IgE antibodies, although with a limited number of drugs, and they have proven complementary to in vivo methods. We show the importance of the allergological workup of the patient within less than 1 year from the occurrence of the allergic reaction in order to obtain positive results in both in vivo and in vitro tests.

Sublingual immunotherapy in peach allergy: monitoring molecular sensitizations and reactivity to apple fruit and Platanus pollen

BACKGROUND

Peach allergy is prevalent, persistent, and potentially severe and as such is a target for immunotherapy. Our aims were to evaluate the profile of sensitization to Rosaceae allergens and the effects of sublingual peach immunotherapy on immunoglobulin (Ig) E levels to these allergens, to monitor for neosensitizations, and to check if this treatment modified other Rosaceae fruit and pollen-related sensitizations.

METHODS

A double-blind placebo-controlled trial was conducted on 56 peach-allergic patients who received, sublingually, a standardized peach extract quantified in mass units of Pru p 3, or placebo for 6 months. IgE to recombinant (r) Mal d 1, rMal d 4, rPru p 3, and natural (n) Art v 3 and skin prick test (SPT) reactivity to Platanus pollen and apple extracts evaluated before treatment (T0), after 1 month (T1) and after and 6 months (T6) were recorded.

RESULTS

In total, 18.5% of patients recognized rMal d 1, 83.3%, rPru p 3, 24.1%, rMal d 4, and 25.9% nArt v 3. IgE to Pru p 3 rose from T0 to T1 in both the active group (P = .003) and the placebo group (P = .022), and remained elevated at T6 in the active group (P = .001). IgE to other purified allergens did not change significantly and no relevant neosensitizations were detected. SPT reactions to peach decreased from T0 to T6 in the active group (P < 0.05). Reactivity to peach (T1 and T6) and apple (T6) was lower in the active group than in the control group.

CONCLUSIONS

The main allergen was Pru p 3. Changes in rPru p 3 IgE levels and in peach and apple extract SPT were induced by sublingual immunotherapy.

Randomized double-blind, placebo-controlled trial of sublingual immunotherapy with a Pru p 3 quantified peach extract

BACKGROUND

Peach allergy is highly prevalent in the Mediterranean area; it is persistent and potentially severe, and therefore a prime target for immunotherapy. We aimed to study the efficacy and safety of sublingual immunotherapy (SLIT) with a peach extract quantified in mass units for Pru p 3, the peach lipid transfer protein.

METHODS

Randomized, double-blind, placebo-controlled (DBPC) clinical trial. The main efficacy outcome was the change in the response to a DBPC food challenge (DBPCFC) with peach. Secondary efficacy outcomes were the changes in skin prick test (SPT), and in specific immunoglobulin E (IgE) and IgG(4) to Pru p 3. Tolerance was assessed with a careful recording of adverse events.

RESULTS

After 6 months of SLIT, the active group tolerated a significantly higher amount of peach (three- to ninefold), presented a significant decrease (5.3 times) in SPT, and a significant increase in IgE and IgG(4) to Pru p 3. No significant changes were observed within the placebo group. Statistically significant inter-group differences were only observed in the SPT and IgG(4) responses. No serious adverse events were reported. Systemic reactions were mild, and observed with a similar frequency in both groups. Local reactions were significantly more frequent in the active group (three times) and 95% of them restricted to the oral cavity.

CONCLUSION

In this first exploratory clinical trial, SLIT for peach allergy seems to be a promising therapeutic option that could modify the clinical reactivity of the patients to peach intake and the underlying immunological response with a good tolerance.

Guidelines on the clinical usefulness of determination of specific immunoglobulin E to foods

The diagnostic gold standard for food allergy is challenge with the culprit food, particularly in double-blind placebo-controlled challenge. This approach involves risks and consumes both time and resources. A more efficient system would be desirable. The detection of serum specific immunoglobulin E (sIgE) against the culprit food enables us to establish sensitization, although this is not always accompanied by clinical reactivity. Age, symptoms (immediate/late reaction, local/systemic reaction), concomitant condition (eg, atopic dermatitis, pollinosis) and selection sample criteria (eg, presence of symptoms related to ingestion, positive skin prick test result) can influence the detection and concentration of IgE against foods. We analyze the clinical usefulness of sIgE determination in light of studies in which oral food challenge is used as the diagnostic method. We review clinical usefulness at diagnosis and in the decision to reintroduce the food, as well as the prognostic value of the determination of IgE to foods.

Double-blind, placebo-controlled study of Alternaria alternata immunotherapy: clinical efficacy and safety

Allergen-specific immunotherapy (ASIT) with fungal extracts has been beset by safety and efficacy problems, which result mainly from qualitative and quantitative variations. Little has been published on the safety and efficacy of these extracts. The objective was to analyze the safety and efficacy of ASIT with an Alternaria alternata extract. A total of 28 patients were selected with rhinitis and/or bronchial asthma because of Alternaria allergy and monosensitization to molds. The patients were randomized to an active ASIT or placebo group, both groups on a conventional immunotherapy schedule (increasing weekly doses until maintenance dose and then monthly doses). Adverse reactions were classified with the European Academy of Allergology and Clinical Immunology system. Clinical efficacy was analyzed for a year with symptom/medication diary cards, peak expiratory flow (PEF) measures, clinical severity score, severity of symptoms (visual analog scale), subjective evaluation of treatment by the patient and the physician, and a quality of life questionnaire. Twenty-three patients completed the study; all reached the established maintenance dose with only two mild adverse reactions in the whole sample. Significant improvements were found after 6 months in respiratory symptoms in the active treatment group, and in all symptoms in both groups. PEF increased significantly in the active treatment group but not in the placebo group. The severity of asthma decreased in the active treatment group, and the severity of rhinitis decreased in both groups. Visual analog scale scores for severity of symptoms improved in all phases in the active treatment group, but only after 12 months in the placebo group. Physicians judged the disease course as significantly better in the active treatment group. ASIT with the A. alternata extract was safe, with clinical improvements after one year of treatment.

Basophil Activation Test and specific IgE measurements using a panel of recombinant natural rubber latex allergens to determine the latex allergen sensitization profile in children

There are no documented studies that describe natural rubber latex (NRL) sensitization in children with a history of surgical intervention but without any congenital malformation (urogenital anomalies, spina bifida, etc.), although some authors have studied NRL allergy in children without a history of surgical intervention. The aim of this work was to evaluate the sensitization profile to single NRL allergens in children without spina bifida and without repeated surgical interventions, by using different recombinant and natural latex allergens in two analytical techniques: specific serum immunoglobulin E (IgE) quantification and flow cytometry determination of activated basophils expressing CD63, after stimulating cells from patients with NRL allergens. A total of 23 patients and 10 healthy children were selected. Conjunctival and in-use NRL provocation tests were carried out, as well as specific IgE determination in all patients' and controls' sera with the recombinant NRL allergens: rHev b 1, rHev b 2, rHev b 3, rHev b 5, rHev b 6.01, rHev b 6.02, rHev b 8, rHev b 9 and rHev b 11 and with NRL (k82) using appropriate ImmunoCAPs. The Basophil Activation Test (BAT) was performed with whole latex extract and with the recombinant allergens rHev b 5 and rHev b 6.01, as well as with the natural allergen Hev b 6.02. The sensitivity and the specificity of NRL-specific IgE (k82) were 100%. Positive IgE responses to rHev b 5 were found in sera of 10 children, to rHev b 6.01 in 16 and for rHev b 6.02 in 15 children's sera. Specific IgE to rHev b 8 was found in four sera of the children. We only found significant differences in sensitization to rHev b 5 in children with two or more surgical interventions compared with the non-intervened group or those with only one intervention. Specific IgE in sera of children with latex-fruit syndrome recognized rHev b 6.02, but not to rHev b 11. The patients sensitized to Hev b 8, Hev b 9 and/or Hev b 11 were atopic. The four patients presenting a positive response to the NRL profilin Hev b 8 were allergic to pollen. The BAT against whole NRL extract was positive in 22 of 23 children; against rHev b 5 in 14 of the patients studied; against rHev b 6.01 in seven cases and against nHev b 6.02 in 19 children. In all the control subjects, the results using this technique were negative. If combined rHev b 5, rHev b 6.01 and nHev b 6.02 together, BAT could detect 20 of the 23 children with latex allergy. The combined use of ImmunoCAP with all the recombinant NRL allergens and BAT with rHev b 5, rHev b 6.01 and nHev b 6.02, enabled the identification of NRL allergy in 22 of 23 patients. There is a positive and significant correlation between sensitization to Hev b 5 and the number of interventions. BAT and allergen-specific IgE determination could be used as first-line in vitro diagnostic tests in patients with NRL allergy.

Comparative analysis of the bronchodilator response measured by impulse oscillometry (IOS), spirometry and body plethysmography in asthmatic children

BACKGROUND

Asthma is common among young children. The assessment of respiratory resistance by the impulse oscillometry system (IOS), based on the superimposition of respiratory flow by short-time impulses, requires no patient active collaboration.

AIM

We evaluated the baseline repeatability and bronchodilator response of IOS indices in preschool children, their correlation with spirometry and whole body plethysmography, and differences between atopic and nonatopic children.

PATIENTS AND METHODS

Thirty-three asthmatic children (3-6 yrs.) underwent IOS measurement (R5rs, R20rs and X5rs) by triplicate at the baseline, after placebo and after salbutamol inhalation. Spirometry (FEV1) and whole body plethysmography (sRaw) were made at the baseline and after salbutamol. Baseline within-test (coefficient of variation: CV%) and between-test repeatability (baseline-placebo) were addressed. Bronchodilator response was evaluated by the SD index (change in multiples of the between-test repeatability).

RESULTS

Baseline repeatability for R5rs was 4.1%. Its values decreased by 2SD after salbutamol inhalation, and correlated with FEV1 and sRaw at both, baseline (r=-0.51 and r=0.49) and post-salbutamol (r=-0.63 and r=0.54). A trend towards correlation between salbutamol-induced changes in R5rs and in sRaw (r=0.33) was observed. Atopic and non-atopic children showed no differences in lung function.

CONCLUSION

IOS was well accepted by young asthmatic children and provided reproducible and sensitive indices of lung function. Resistance values obtained by IOS at low frequency (R5rs) were reproducible and correlated with spirometry and plethysmographic values.

Respiratory allergy to peach leaves and lipid-transfer proteins

BACKGROUND

Several lipid-transfer proteins (LTPs) have been identified as important food allergens, especially in fruits of the Rosaceae family. The major peach (Prunus persica) allergen has been identified, sequenced and designated Pru p 3.

OBJECTIVE

To present Pru p 3 as an aeroallergen able to induce occupational asthma.

METHODS

A thorough investigation was performed in a fruit grower with occupational asthma. Skin prick-prick tests with peach leaves and prick tests with perennial respiratory allergens and pollens, fruits and peach leaf extracts were done. Serum-specific IgE was tested for peach leaf, peach fruit, peach skin and respiratory allergens that were positive in skin prick tests. Specific bronchial provocation tests (BPTs) with extracts of peach leaf were also done. Before and 24 h after the BPT, BPTs with methacholine and sputum induction were done. The IgE reactivity pattern to peach leaf and fruit extracts and to Pru p 3 was identified by using SDS-PAGE and immunoblotting. Blotting inhibition of peach leaf extract by Pru p 3 was also performed. The putative allergen was quantified in leaf and fruit skin extracts with ELISA based on an anti-Pru p 3 antibody.

RESULTS

Skin tests were positive for peach leaf and fruit. The BPT was positive, with immediate and delayed response. This test induced a decrease in PD20 (dose of agonist that induces a 20% fall in FEV1) methacholine and an increase in eosinophils and eosinophil cationic protein in sputum. Peach leaf extract contained concentrations of Pru p 3 similar to those found in peach skin. Specific IgE immunodetection showed that patient's sera reacted with Pru p 3, and with a single major band from the peach leaf extract fully inhibited by Pru p 3.

CONCLUSION

Pru p 3 from peach leaves can act as a respiratory allergen and cause occupational rhinoconjunctivitis and asthma.

Diversity of asparagus allergy: clinical and immunological features

BACKGROUND

Asparagus (Asparagus officinalis) is an extensively grown and consumed vegetable. To a lesser extent than other Liliaceae vegetables, allergic contact dermatitis (ACD) due to asparagus has been reported. However, only a few case reports of asparagus IgE-mediated allergy have been published. In a previous study, we demonstrated that two lipid transfer proteins (LTPs) (Aspa o 1.01 and Aspa o 1.02) were relevant allergens of asparagus.

OBJECTIVE

We retrospectively analysed the 27 patients diagnosed with asparagus allergy during the last 5 years. All of them reported adverse symptoms after either asparagus ingestion or handling. We describe their clinical features and evaluate whether they were associated to immunological findings (immunoblot pattern and skin reactivity to LTPs).

METHODS

Patients underwent skin prick and patch tests with standard panels of vegetables and aeroallergens. Besides crude asparagus extract, two purified LTPs were prick and patch tested. Total and specific IgE measurements and asparagus extract IgE immunoblotting were performed. Patients reporting asthma symptoms underwent specific inhalation challenge to asparagus.

RESULTS

Of the 27 subjects, eight had ACD, 17 had IgE-mediated allergy and two had both ACD- and IgE-mediated allergy. Positive patch tests with the crude asparagus extract but not with LTPs were observed in subjects with ACD (n=10). Of 19 patients with IgE-mediated disease, 10 had contact urticaria after asparagus handling. Of them, five subjects and five others without skin allergy showed respiratory symptoms; of them, eight were diagnosed with occupational asthma confirmed by positive asparagus inhalation challenge, whereas the remaining two had isolated rhinitis. Four patients suffered from immediate allergic reactions related to asparagus ingestion (food allergy); three of them reported anaphylaxis whereas the other had oral allergic syndrome. Positive IgE immunoblotting (bands of 15 and 45-70 kDa) was observed in 10 subjects. Of 10 subjects with positive prick test to LTPs, six showed bands at 15 kDa. Either IgE-binding bands or positive prick tests to LTPs were observed in asthma (62%) and anaphylaxis (67%).

CONCLUSION

Asparagus is a relevant source of occupational allergy inducing ACD and also IgE-mediated reactions. Severe disease (anaphylaxis or asthma) is common and LTPs seem to play a major role. The clinical relevance of LTP sensitization among patients with mild disease or symptom-free subjects should be addressed in prospective studies.

Tolerance of a cluster schedule on the treatment of seasonal allergic respiratory disease with pollen extracts quantified in mass units

In order to evaluate the tolerance of a cluster schedule on specific immunotherapy (SIT), 306 patients were included in a multicenter study. The patients were suffering from rhinoconjunctivitis with/without asthma, caused by sensitization to olive and/or grass pollen. SIT was administered subcutaneously according to a cluster schedule in which the maintenance dose is reached after four visits (3 weeks). The extracts were biologically standardized with major allergens quantified in mass units. Local reactions appeared in 7.2% of the patients and 1.3% of the doses. Systemic reactions (SR) were recorded in 1.2% of the doses administered to 9.5% of the patients. No anaphylactic shock was registered, and all the SR responded fully and rapidly to treatment. There was no difference in SR according to diagnosis or allergen extract used. The majority of SR occurred with the administration of vial of higher concentration (Vial 2: 7 SR (22%), Vial 3: 32 SR (78%), p < 0.05). Of the 32 SR recorded with Vial 3, 13 (41%) were immediate, with no existing association between dose administered and appearance of SR. However, of the 18 delayed SR (56%), 14 occurred after the administration of the first two doses of Vial 3 and four occurred after administration of the second two doses (78% vs 22%, p < 0.05). On the other hand, this regime realized an important saving in cost and time compared to the conventional schedule (1581 fewer doses and 2754 fewer visits were necessary to reach the optimal dose). Considering all these factors, the clinical profile of the proposed regime may be qualified as good. However, future studies are necessary in order to better adjust the schedule to avoid the delayed SR that occurred after the administration of the first two doses of Vial 3.

[Treatment of allergy to mushrooms]

The treatment of patients with respiratory allergy is based on environmental control measures, pharmacological and immunotherapy treatment. The third cause of allergic respiratory disease in our environment is mushrooms, the most frequently involved being the Alternaria class. However, due to the great difficulties in their diagnosis and specific treatment, there are few controlled studies on immunotherapy with mushroom extracts. A clinical test was carried out with a suitable, biologically standardized extract for the diagnosis and treatment of patients allergic to Alternaria. A second phase determined the maximum tolerated dosage of this extract administered through immunotherapy, in depot preparation and in conventional dosage, which was 0.1 mg/ml of Alt a I. This dosage was established as the maintenance dosage in the following phase (double blind test controlled with placebo), in which the efficacy and safety of the immunotherapy with this extract was determined, administered in immunotherapy to the mentioned maintenance dosage, to 28 patients with rhinitis and/or asthma due to allergy to Alternaria. All the patients reached the pre-established maintenance dosage of 1670 BSU. The treatment proved efficient, producing an improvement in the symptoms, respiratory function, subjective evaluation of patient and doctor, and severity of the disease. The immunological response supported the clinical efficacy, with an increase in the IgG and a fall in the IgE over the course of the study. Tolerance to the treatment was excellent, with only two light systemic reactions registered in the 711 dosages administered (0.28% reactions/dosages administered).

[Food allergy in the XXI century]

Food allergy is a clinical state of high frequency and possible risk to life. This article reviews the foodstuffs most often responsible for serious reactions, including data from the Autonomous Community of Navarre. Given that dietetic elimination is the primordial long term treatment for food allergy, its difficulties, limitations and risks are analyzed. Finally, we set out the new perspectives offered by technology in the field of food allergy, both in the production of hypoallergens and in the development of new forms of immunotherapy.

[New techniques in the study of asthma]

Asthma is a chronic inflammatory disease of the airways that is functionally characterized by variability of lung function and bronchial hyper-responsiveness. Its diagnosis and management is commonly hampered by the lack of objective parameters. This article reviews additional techniques for evaluating both, lung function (bronchial challenge with adenosin-monophosphate, lung resistance measurement by either the impulse oscillometry system or whole body pletismography) and bronchial immuno-inflammatory response (induced sputum, condensates of exhaled air, monitoring of nitric oxide in exhaled air), as well as our experience with them.

[Anaphylaxis]

Anaphylaxis is a potentially mortal, underdiagnosed clinical picture. The most frequent triggering agents are drugs and foodstuffs. The first therapeutic option, adrenaline, although clearly indicated, is not carried out with the desired frequency due basically to the high number of cases of anaphylaxis that are not diagnosed as such. In patients with a first episode of anaphylaxis, posterior aetiological diagnosis is crucial to avoid the appearance of new episodes. The only case of anaphylaxis in which immunotherapy with the allergen must be evaluated, is that in which the causal agent is the poison of hymenopters.

[Associations of allergic and asthmatic patients in Europe]

Patients' associations are NGOs that emerge as a result of the needs of patients with chronic diseases that cannot be solved in the doctor's surgery. At the start, the role of the health personnel, in guiding and collaborating with them, was fundamental, and their aims and interests coincided to a high degree. Their healthy operation favored both the patients and, indirectly, the health professionals related to them. However, we must bear in mind that those interests are not identical and, on occasion, can be clearly divergent. This is why the independence of these associations cannot be renounced upon, and they are managed according to the growth in their size and social influence.

[Immunotherapy with grouped doses]

Once the efficacy and safety of immunotherapy with allergen extracts has been shown, recently it has become evident the need for perfecting those aspects of the treatment that can be improved, such as its dosage form. The conventional dosage of subcutaneous immunotherapy in the phase of dose increase is slow in reaching an efficient level. For this reason other alternative dosages to the conventional one have been tried out, such as grouped dosages, which shorten this period of dose increase. On condition that the safety of the treatment is guaranteed, these doses offer the advantages of reducing the economic cost and the time involved, of reducing the discomfort of the treatment and of improving the patient's adherence to the treatment, and possibly of reaching clinical efficacy more rapidly. Nonetheless, it is not easy to determine the suitable dosage of administration (the shortest and with the least number of adverse reactions) and this article reviews the existing problems when it comes to designing these grouped doses. Finally, we present the results of a comparative study between the conventional dose and a grouped dose, with a double blind design, carried out by us, which shows that the grouped dose is quicker in achieving the desired clinical efficacy, shortens the times of reduction of cutaneous sensitivity to the allergen and of modification of the immunological parameters, all with a low frequency of adverse reactions that is similar to that registered with the conventional dosage.

Occupational asthma from natural rubber latex. Specific inhalation challenge test and evolution

BACKGROUND

Natural rubber latex (NRL) is the most frequent cause of occupational respiratory problems in hospital workers.

OBJECTIVE

To describe the diagnostic methodology, including the specific inhalation challenge (SIC), used on patients diagnosed as having occupational asthma due to NRL in our Allergy Department during a 6-year period from 1989 to 1995.

METHODS

In 19 patients diagnosed as having occupational asthma due to NRL, clinical severity was assessed with a combined score for symptoms and medication use. Skin prick tests with aeroallergens, latex, papain, kiwi and chestnut, total IgE, serum-specific latex IgE, respiratory function study, methacholine test, specific conjunctival test, and SIC test with latex were done.

RESULTS

All but three patients worked in hospitals. All presented urticaria and rhinoconjunctivitis, and six also suffered anaphylaxis, usually preceded by asthma. Clinical fruit allergy was present in eight patients. The latency period was variable (0.25-27 years). The intensity of symptoms was low to moderate. Specific IgE, skin prick, and conjunctival tests to latex were positive in all cases. SICs were done in 12 patients. All of them presented isolated immediate reactions. No adverse reactions were observed. Duration of follow-up ranged from 1 to 7 years. Twenty-six percent of the patients kept their job, 26% changed jobs but remained in health care, and 48% switched to jobs unrelated to health care. Only 16% were free of symptoms without treatment, while 32% needed bronchodilators and 52% needed inhaled steroids. The specific bronchial challenge test was safe, but it did not predict the course of the illness. Duration of exposure and intensity of symptoms did correlate with prognosis, however.

CONCLUSIONS

NRL acts as a common aerollergen. Minor symptoms often precede occupational asthma. The SIC test was safe in the hands of trained technicians. Occupational asthma due to NRL seems to have a poor prognosis.

Characterization of asparagus allergens: a relevant role of lipid transfer proteins

BACKGROUND

No asparagus allergen has been characterized to date. Lipid transfer proteins (LTPs) have an ubiquitous distribution in plant foods and have been identified as relevant allergens in some fruits, seeds, and pollens.

OBJECTIVE

We sought to identify asparagus allergens and to evaluate the potential involvement of the panallergen LTP family in asparagus allergy.

METHODS

Eighteen patients with asthma, anaphylaxis, and/or contact urticaria after asparagus ingestion or exposure and positive skin prick test (SPT) responses and serum-specific IgE levels to asparagus were selected. Two LTPs were isolated from crude asparagus extract by using chromatographic methods and characterized by means of N-terminal amino acid sequencing. Both isolated proteins were tested by means of immunodetection, CAP inhibition assays, and SPTs. Additional asparagus allergens were located by using immunodetection with a pool of sera from patients allergic to asparagus and with rabbit polyclonal antibodies to sunflower pollen profilin and anti-complex asparagine-linked glycans antibodies.

RESULTS

The purified LTPs showed an N-terminal amino acid sequence similar to that of Pru p 3 and a strong reaction to anti-Pru p 3 antibodies. Each isolated protein reached inhibition values of up to 60% in CAP inhibition assays against asparagus extracts and elicited positive SPT responses in 9 of 18 patients with asparagus allergy. Immunodetection assays allowed us to identify profilin and cross-reacting carbohydrate determinants as asparagus IgE-binding components.

CONCLUSION

Asparagus LTPs are relevant allergens. In addition, profilin and glycoproteins harboring complex asparagine-linked glycans can also be involved in asparagus allergy.

Allergen vaccination with a liposome-encapsulated extract of Dermatophagoides pteronyssinus: a randomized, double-blind, placebo-controlled trial in asthmatic patients

BACKGROUND

Liposomes are potent immunologic adjuvants and have been proposed as allergen carriers in allergy vaccination.

OBJECTIVE

We sought to investigate the efficacy and safety of vaccination with Dermatophagoides pteronyssinus encapsulated in liposomes.

METHODS

We conducted a double-blind, placebo-controlled study. Fifty-five asthmatic patients sensitized to mites were randomly assigned vaccination with D pteronyssinus extract encapsulated in liposomes or empty liposomes for a period of 12 months. The principal parameters were symptom and medication-consumption scores. The percentage of healthy days (ie, days without medication and with absent or mild symptoms) was calculated. Immediate and late skin test results, allergen bronchial challenge test results, and allergen-specific serum immunoglobulin levels were evaluated before and after treatment.

RESULTS

All clinical scores were markedly lower in the active group than in the placebo group after vaccination. Nearly half (45.8%) of the patients actively treated reduced their symptom and medication scores by at least 60% versus only 12% of patients receiving placebo treatment (P =.0388). The percentage of healthy days in the active group rose from 10.5% before treatment to 64.5% afterward (P =.0008). Reduction in organ sensitivity was demonstrated by skin prick test responses (P <.01), late-phase response after intradermal testing (P =.009), and bronchial challenge test results (P =.026) in the active group. Serum levels of specific IgG increased throughout the treatment, whereas specific IgE levels showed only an initial transient increase. No change in these parameters was observed in the placebo group. Vaccination was well tolerated, and no subcutaneous nodules appeared.

CONCLUSION

Vaccination with D pteronyssinus encapsulated in liposomes is an effective and safe treatment for allergy-induced asthma.

Tolerance of immunotherapy with a standardized extract of Alternaria tenuis in patients with rhinitis and bronchial asthma

We studied the safety of immunotherapy with an Alternaria extract in patients with rhinitis and bronchial asthma. The few studies that have investigated immunotherapy with mold allergens suggest that they cause adverse reactions more frequently than do other extracts. All treatments prescribed by our allergology service with Alternaria immunotherapy between 1988 and 1996 were recorded and analyzed. In all cases a biologically standardized depot extract of Alternaria tenuis containing 5 BU/ml was used according to a conventional immunotherapy schedule. During the study period 129 patients received immunotherapy with Alternaria extract. Of the 3,892 doses given, 1.95% led to adverse reactions, which occurred in 39.5% of the patients. Most of the adverse reactions were systemic and mild, and reproduced the underlying disease. The risk of adverse reactions was significantly higher in children, patients with asthma, and during the initial phase of treatment. Patients who suffered from adverse reactions had a significantly higher level of total and specific IgE. It was concluded that tolerance of Alternaria mold extract was worse than for other allergenic extracts, although most reactions recorded were mild. The risk of adverse reactions was greater in children and patients with asthma, and during the initial phase of immunotherapy.

Identification of allergens involved in occupational asthma due to carmine dye

BACKGROUND

Carmine has been implicated as an etiologic agent of occupational asthma, but the allergens involved have not been yet identified.

OBJECTIVE

To identify the allergens involved in occupational asthma due to carmine dye.

METHODS

An in vitro study based in SDS-PAGE and IgE immunoblotting with carmine and cochineal extracts was performed. Sera from three carmine dye workers diagnosed with occupational asthma induced by carmine dye and from seven nonatopic subjects were used.

RESULTS

Three proteins of around 30, 28, and 17 kD in raw cochineal extract and another protein of 50 kD in the boiled one were demonstrated by SDS-PAGE. Two proteins of around 50 and 28 kD were observed in the carmine extract by the same technique. Specific IgE binding bands at 17 kD in cochineal raw extract, at 50 kD in the boiled one, and at 28 kD in carmine extract were demonstrated by IgE immunoblotting.

CONCLUSIONS

We have identified three allergens of around 17, 28, and 50 kD implicated in occupational asthma of three carmine workers.

Airway inflammation in asthma and perennial allergic rhinitis. Relationship with nonspecific bronchial responsiveness and maximal airway narrowing

BACKGROUND

Eosinophilic airway inflammation is the hallmark of asthma, but it has also been reported in other conditions such as allergic rhinitis. We have tested whether the analysis of cells and chemicals in sputum can distinguish between patients with mild allergic asthma, those with allergic rhinitis, and healthy controls. The relationship between inflammation markers in sputum and nonspecific bronchial hyperresponsiveness to methacholine (BHR) (PD20 and maximal response plateau [MRP] values) was also evaluated.

METHODS

We selected 31 mild asthmatics and 15 rhinitis patients sensitized to house-dust mite. As a control group, we studied 10 healthy subjects. Every subject underwent the methacholine bronchial provocation test (M-BPT) and sputum induction. Blood eosinophils and serum ECP levels were measured. Sputum cell differentials were assessed, and eosinophil cationic protein (ECP), tryptase, albumin, and interleukin (IL)-5 levels were measured in the entire sputum supernatant.

RESULTS

Blood eosinophils and serum ECP levels were higher in asthma patients and rhinitis than in healthy controls, but no difference between asthma patients and rhinitis patients was found. Asthmatics had higher eosinophil counts and higher ECP and tryptase levels in sputum than rhinitis patients or control subjects. Sputum albumin levels were higher in asthmatics than in controls. Rhinitis patients exhibited higher sputum eosinophils than healthy controls. An association between sputum eosinophil numbers and MPR values (r= -0.57) was detected, and a trend toward correlation between sputum ECP levels and PD20 values (r= -0.47) was found in the rhinitis group, but not in asthmatics. No correlation between blood eosinophilic inflammation and lung functional indices was found.

CONCLUSIONS

Induced sputum is an accurate method to study bronchial inflammation, allowing one to distinguish between rhinitis patients and mildly asthmatic patients. The fact that no relationship was detected between sputum inflammation and BHR suggests that other factors, such as airway remodeling, may be at least partly responsible for BHR in asthma.

Effect of current exposure to Der p 1 on asthma symptoms, airway inflammation, and bronchial hyperresponsiveness in mite-allergic asthmatics

The existence of a dose-response relationship between indoor allergen exposure and sensitization has been widely described, but the effect of allergen exposure on asthma activity (symptoms, bronchial hyperresponsiveness [BHR], and inflammation) is not clear. Our aim was to determine the existence of an association among current exposure to mite allergens and symptoms, BHR, and airway inflammation assessed in blood and sputum from asthmatic patients sensitized to Dermatophagoides pteronyssinus. We selected 31 mild and recently diagnosed (12-24 months) asthma patients sensitized to D. pteronyssinus. Allergenic exposure (Der p 1, Der 2) was assessed by a commercial assay based on monoclonal antibodies (mAb), carried out on the dust samples collected from patients' beds in a standardized way. Patients completed an asthma symptom questionnaire and underwent skin tests, methacholine bronchial challenge, and sputum induction. Sputum cell profile was analyzed and eosinophil cationic protein (ECP), tryptase, albumin, and interleukin(IL)-5 levels were quantified in sputum supernatant. Total eosinophil numbers and ECP levels were measured in blood samples. Most patients were exposed to Der p 1 levels under 2 microg/g of dust. Der p 1 exposure was higher among the subjects with positive sputum tryptase detection (P = 0.020). Der p 1 levels showed a trend toward correlation with asthma symptoms (P = 0.066, r = 0.36) and correlated with sputum tryptase levels (P = 0.032, r = 0.42). No relationship between BHR, eosinophilic inflammation, and allergenic exposure was found. Our results suggest that asthma symptoms and lung mast-cell activation are at least partially dependent on current allergen exposure. The lack of correlation between mite exposure, eosinophilic inflammation, and BHR supports the role of other factors that enhance the immunologic response initiated by allergen, increasing the activity of asthma.

Cluster versus conventional immunotherapy in patients allergic to Dermatophagoides pteronyssinus: a controlled study of in vivo and in vitro parameters

We designed a cluster schedule of immunotherapy for patients allergic to Dermatophagoides pteronyssinus which showed good safety and clinical efficacy. Here we compare the in vivo and in vitro changes with those of a conventional schedule in a controlled trial. Sixty-three patients were randomized as follows: 29 were treated with the cluster schedule, 15 with a conventional schedule and 19 received no immunotherapy. A standardized extract was used. Changes in in vivo parameters (skin prick test and conjunctival provocation test) and in in vitro parameters (IgE, IgG, IgG1 and IgG4 for the complete extract, Der p 1 and Der p 2) were measured before immunotherapy (T0), on reaching maintenance phase (T1), and after 6 (T2), 12 (T3) and 18 months of maintenance (T4). Cutaneous reactivity showed a significant decrease from T1 in both the cluster and conventional schedules, and conjunctival reactivity was also significantly lowered from T1 in these groups. Specific IgE decreased and specific IgG, IgG1 and IgG4 increased significantly from T1 in the cluster and conventional schedules. Neither of these parameters showed any changes in the group without immunotherapy. In conclusion, our cluster schedule induced changes in cutaneous and conjunctival reactivity and in immunological parameters that were similar to those achieved with the conventional schedule; these changes did not appear in patients who did not undergo immunotherapy.