Impact of climate change-related environmental factors on the allergens production and the epidemiology and severity of allergic pathologies.

BACKGROUND: Allergic disease affects up to 40% of the global adult population, a proportion that is increasing with environmental changes related to global warming. METHODS: We undertook a systematic review of the literature to identify and evaluate the current evidence of the impact of climate change-related environmental factors on the allergen production and the epidemiology and severity of allergic pathologies. PECO criteria were established and guided the literature searches of the PubMed and Cochrane databases (Jan 1, 2016 to Dec 31, 2021). Study outcomes were categorized and grouped to facilitate data synthesis. Outcomes were classified as significant (statistical significance <0.05), non-significant (p>0.05) or undetermined (p value not reported). Study quality was assessed using MMAT analysis. RESULTS: Of 195 studies, 40 were considered relevant and 9 of them provided data to be included in the data quantitative synthesis. Environmental factors, including the presence of pollutants, temperature, and drought, influenced the type, volume, and timing of exposure to local aeroallergens. The most relevant environmental factor was the presence of environmental pollutants, of which tropospheric ozone was the most frequently associated to changes in allergen production, prevalence, and severity of allergic disease. Also, several publications demonstrated the impact of environmental factors on the healthcare burden. CONCLUSIONS: Climate-change related environmental factors increased allergic disease in terms of prevalence, severity, and healthcare burden due to alterations in allergen exposure (volume and type) with the presence of pollutants such as ozone being the most commonly reported driver of such increase.

Clinical trial to assess tolerability and subrogate efficacy effects of an abbreviated schedule with house dust mites mixture subcutaneous immunotherapy.

Summary: Objective. To evaluate the tolerability and efficacy of Dermatophagoides pteronyssinus/Dermatophagoides farinae mixture subcutaneous immunotherapy (SCIT). Methods. Patients received an abbreviated build-up schedule. The aims were: number, percentage, and severity of adverse reactions. Secondary outcomes included: changes in immunoglobulin titers and changes in dose-response skin prick tests. Results. Out of 289 administrations, 17% elicited any clinically relevant adverse reaction. Most of them were local reactions (LR) (9.4%) and the rest (7.6%) were systemic. Significant increases in sIgG and sIgG4 were detected in serum samples. Cutaneous reactivity decreased significantly. Conclusions. SCIT with house dust mites mixture of ROXALL Medicina España S.A. seems to have an acceptable tolerability profile, induces blocking IgG and decreases skin reactivity.

Epidemiology of asthma exacerbations and their relation with environmental factors in the Basque Country.

BACKGROUND: Asthma is a highly prevalent chronic inflammatory disease characterised by reversible airflow obstruction and hyperreactivity and inflammation of the airways. Factors that cause and/or trigger asthma attacks include host-related factors (genetic predisposition, obesity and sex) and environmental factors (allergens, infections, occupational sensitisation, smoking status, pollution and diet). OBJECTIVE: To describe the epidemiology of asthma exacerbations (AEs) in the Basque Country and to explore its relationship with potentially associated environmental variables. We studied a total of 31,579 emergency department (ED) visits and 28,189 hospitalisations due to asthma. We describe the trends, incidence, seasonality and the influence of age and sex, as well as of exposure to NO2 , CO, PM, O3 , and pollen, temperature, relative humidity and flu status. We calculated the Pearson's R correlation coefficient for the study variables. RESULTS: The incidence was 486 and 88.9 cases per 100,000 people for ED visits and hospitalisations, respectively. Slightly over half (53.5%) of the ED cases were male, while females represented 62.6% of the hospital admissions. Hospitalisations are tending to decrease in children and increase in over 64-year-olds. Peaks in cases occur at the beginning of autumn in children and in winter in adults. AEs were correlated positively with exposure to NO2 , CO and to the influenza virus and negatively with temperature and exposure to O3 . These relationships vary, however, with age and season. CONCLUSIONS AND CLINICAL RELEVANCE: Rates of hospitalisation for AEs and trends in these rates over time are different in adults and children with the patterns varying by sex, season and environmental conditions.

ESPRINT-15 questionnaire (Spanish version): reference values according to disease severity using both the original and the modified ARIA classifications.

OBJECTIVE: ESPRINT-15 is a specific and validated instrument to measure health-related quality of life in adults with allergic rhinitis. The aim of this study was to obtain new reference values based on disease severity using both the original and the modified versions of the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines. METHODS: ESPRINT-15 was administered to a representative sample of adults with allergic rhinitis in Spain. As in a previous study by our group, means and percentiles were analyzed for 16 quotas based on gender, allergic rhinitis type (intermittent vs persistent), and 4 symptom intensity groups according to the total symptom score (TSS4). The novel aspect of the present study was our application the severity criteria proposed by both the original and the modified ARIA classifications. RESULTS: Of the 2756 patients in our previous dataset, 2580 were included in the present analysis. In terms of symptom severity, women ha relatively more intense symptoms than men with both ARIA classifications. In fact, using only the modified ARIA classification, we were abl to determine that severe rhinitis is moderately more frequent in women (27% vs 23%), although the difference is not statistically significant. CONCLUSIONS: The new set of reference values enables the ESPRINT-15 questionnaire to be adapted to the current severity classification Consequently, this quality of life tool (http://www.seaic.org/inicio/esprint) can be easily used and better interpreted in daily clinical practice.

Diagnostic utility of components in allergy to Anisakis simplex.

BACKGROUND: In our region, Anisakis allergy is responsible for 8% of acute urticarial reactions, 25% of which progress to anaphylactic shock. The poor specificity of skin tests and in vitro specific immunoglobulin (Ig) E means that Anisakis allergy is frequently overdiagnosed. OBJECTIVE: We studied the diagnostic value of 2 Anisakis allergens: rAni s 1 and rAni s 3. METHODS: Skin tests, the basophil activation test (BAT), and specific IgE determination were performed with rAni s 1 and 3 in 25 patients allergic to Anisakis, 17 atopic controls, and 10 controls with acute urticaria and positive skin test and sIgE results for Anisakis, but no allergy to Anisakis. RESULTS: For rAni s1, skin tests had a sensitivity and specificity of 100% and specific IgE had a sensitivity and specificity of 100% in the atopic control group and 90% in the urticaria control group. BAT had a sensitivity of 96.8% and a specificity of 100% in the atopic control group and 66.7% in the urticaria control group. For rAni s 3, only 1 patient had positive specific IgE results to rAni s 3. All other techniques gave negative results in patients and controls CONCLUSIONS: rAni s 1 is the major allergen of Anisakis and the target allergen when diagnosing allergy to Anisakis, rAni s 3 is not relevant when attempting to explain false-positive results.

Discrimination between moderate and severe disease may be used in patients with either treated or untreated allergic rhinitis.

BACKGROUND: Allergic rhinitis (AR) is a common disease with major socioeconomic burden and a significant impact on quality of life. OBJECTIVE: The aim of this study was to discriminate between moderate and severe AR patients whether receiving treatment or not, using a modified criterion of allergic rhinitis and its impact on asthma (ARIA) classification. METHODS: The modified ARIA severity classification (J Allergy Clin Immunol, 120, 2007, 359) categorizes AR as mild (no items affected), moderate (1-3 items affected), and severe (all four items affected). We applied these criteria to 1666 treated and 1058 untreated AR patients and compared their symptoms total four-symptom score (T4SS) and quality of life (ESPRINT-15), according to their clinical severity. RESULTS: Allergic rhinitis clinical status was significantly worse (P < 0.001) in treated than in untreated patients. For both treated and untreated patients, T4SS and ESPRINT-15 Quality of life scores were significantly worse (P < 0.001) in severe than in moderate patients. CONCLUSIONS: The modified ARIA severity classification is a useful clinical tool to discriminate moderate from severe AR among both treated and untreated patients.

Comparison of the efficacy and safety of bilastine 20 mg vs levocetirizine 5 mg for the treatment of chronic idiopathic urticaria: a multi-centre, double-blind, randomized, placebo-controlled study.

BACKGROUND: Bilastine is a novel nonsedative H(1)-receptor antagonist, which may be used for the symptomatic treatment of chronic idiopathic urticaria (CU). The aim of this study was to compare the clinical efficacy and safety of bilastine 20 mg vs levocetirizine 5 mg and placebo in CU patients with moderate-to-severe symptoms. METHODS: Overall 525 male and female subjects aged 18-70 years were randomized to receive bilastine 20 mg, levocetirizine 5 mg or placebo, once daily for 28 days, in double-blind manner, in 46 centres across Europe and Argentina. Patients rated symptoms of pruritus, number of wheals, and maximum size of wheals (on predefined scales) as reflective (over past 12 h) symptoms twice daily, for assessment of change from baseline in the total symptoms scores (TSS) over 28 days as the primary efficacy measure. Changes in reflective and instantaneous symptoms scores, Dermatology Life Quality Index (DLQI), and CU-associated discomfort and sleep disturbance were assessed as secondary outcomes. Safety was assessed according to adverse events, laboratory tests and electrocardiograms. RESULTS: Bilastine reduced patients' mean reflective and instantaneous TSS from baseline to a significantly greater degree than placebo (P < 0.001); from day 2 onwards of treatment. The DLQI, general discomfort, and sleep disruption were also improved significantly in bilastine-treated patients as compared with placebo-treated patients (P < 0.001 for all parameters). Comparison with levocetirizine indicated both treatments to be equally efficacious as well as equally safe and well tolerated as compared with placebo. CONCLUSIONS: Bilastine 20 mg is a novel effective and safe treatment option for the management of CU.

Component-resolved diagnosis of pollen allergy based on skin testing with profilin, polcalcin and lipid transfer protein pan-allergens.

BACKGROUND: Allergy diagnosis needs to be improved in patients suffering from pollen polysensitization due to the existence of possible confounding factors in this type of patients. OBJECTIVE: To evaluate new diagnostic strategies by comparing skin responses to pan-allergens and conventional allergenic extracts with specific IgE (sIgE) to purified allergen molecules. METHODS: One thousand three hundred and twenty-nine pollen-allergic patients were diagnosed by a combination of an in vitro method with a panel of 13 purified allergens, including major allergens and pan-allergens, using a high-capacity screening technology (ADVIA-Centaur) and skin prick test (SPT) to pan-allergens and conventional extracts. RESULTS: There was a high concordance (kappa index) between in vitro (sIgE to major allergens) and in vivo (SPT to conventional extracts) methods in patients who were not sensitized to pan-allergens, but SPT with conventional extracts failed to diagnose patients with sensitization to pan-allergens. In patients who were simultaneously sensitized to polcalcins and profilins, there was a duplication both in the number of sensitizations to major allergens and in the years of disease evolution. There was a statistical association between sensitization to profilins and/or lipid transfer proteins and food allergy (P<0.0001). CONCLUSION: The novel diagnostic strategy has proven to be a valuable tool in daily clinical practice. Introduction of routine SPT to pan-allergens is a simple and feasible way of improving diagnostic efficacy. Patients sensitized to pan-allergens should be tested by an adequate panel of allergenic molecules in order to identify the allergens that are responsible for the allergic disease.

Reference values for facilitating the interpretation of the ESPRINT-15 questionnaire (Spanish version).

OBJECTIVE: ESPRINT-15 is a specific, short-form instrument to measure health-related quality of life in adults suffering from allergic rhinitis. The aim of this study was to obtain reference values in order to improve its interpretability. METHODS: ESPRINT-15 was administered to a representative sample of Spanish adults with allergic rhinitis. Means and percentiles were obtained, taking into account the kind of rhinitis (persistent/intermittent) and symptom severity (very mild/mild/moderate/severe). RESULTS: A total of 2756 patients participated in the study. Mean (SD) scores were significantly lower (better) for men than for women (2.2 [1.4] vs 2.4 [1.4], P<.001, effect size [ES] is congruent to 0.15). Patients with intermittent rhinitis showed better scores than patients with persistent rhinitis (2.1 [1.4] vs. 2.5 [1.4], P<.001, ES is congruent to 0.21). Mean (SD) scores were higher (worse) when severity of symptoms increased, ranging from 0.9 (0.9) (very mild) to 3.7 (1.0) (severe) (ES is congruent to 1.0 between each consecutive group of symptom severity). CONCLUSIONS: The magnitude of the differences found among groups of patients reinforces the usefulness of providing reference values stratified by gender, type of allergic rhinitis, and symptom severity. The percentiles obtained can be used in clinical practice to evaluate individual scores, and assign the patient to the corresponding reference group.

Allergenicity and cross-reactivity of pine pollen.

BACKGROUND: Pine pollen has long been considered a non-allergenic pollen. The large size of the grain and its low levels of proteins are the main reasons invoked to explain this low allergenicity. The aim of this study was to describe the main allergenic bands of Pinus radiata (PR) and its cross-reactivity with other pine species, other conifers and grass pollen. METHODS: Sixty-five pine-pollen-allergic patients (51% also sensitized to grass pollen) were studied. Skin prick tests (SPT) to a battery of allergens including PR, Pinus pinea, Pinus sylvestris, Pinus nigra and Cupressus sempervirens pollens and specific IgE determination to PR and Pinus strobus were performed. IgE-immunoblotting to a PR extract and other pine pollens was also carried out. UniCAP inhibition and immunoblotting inhibition studies were performed to assess the cross-reactivity between different pollens. RESULTS: The SPTs were positive with all the pine pollen extracts tested in 69% of the patients. Specific IgE was positive to PR or P. strobus in 77% of the patients, and to Lolium perenne in 51%. Nine different allergenic bands were detected. The two main allergens were a 42 kDa band recognized by 85% of the patients and a band of approximately 6-8 kDa recognized by 40%. A high degree of cross-reactivity was observed between different pine pollen species, but not between pines and C. sempervirens pollen. A partial cross-reactivity could be seen between pine and grass pollens only in patients also sensitized to L. perenne. CONCLUSIONS: Pine pollen should be considered as a potential allergenic pollen especially where this pollen is abundant. The detection of a high number of patients that were monosensitized to pine pollen suggests the possibility of treating these patients with specific immunotherapy.

Component-resolved in vitro diagnosis in peach-allergic patients.

BACKGROUND: The in vitro diagnosis of pollen-related food allergy presents low specificity and reproducibility with many conventional extracts. This can be improved using natural purified allergens, recombinant purified allergens, or both. OBJECTIVE: We compared specific immunoglobulin (Ig) E determination (slgE), the basophil activation test (BAT), the histamine release test (HRT), and the cellular allergen stimulation test (CAST) using natural and recombinant allergens in the diagnosis of peach allergy. METHODS: Thirty-two peach allergic patients were studied. Skin prick tests were performed with commercial peach and extract with Mal d 1, nPru p 3, and profilin (nPho d 2). slgE, BAT, CAST, and HRT were determined using rPru p 3, rMal d 3, rBet v 1, rMal d 1, and rMal d 4. RESULTS: Agreement between the techniques was good with all the allergens, except HRT with rMal d 1 and rMal d 4. With rPru p 3, slgE, CAST, BAT, and HRT showed sensitivity values of 88%, 81%, 72%, and 69% and specificity values of 100%, 93%, 97%, and 83%, respectively. In patients with systemic symptoms or contact urticaria, the values were 100%, 85%, 81%, and 81%. In patients with oral allergy syndrome, sensitivity to profilins or homologues of Bet v 1 was detected in 100% of the cases by all the techniques, except by HRT with rMal d 1, which detected 66% of the cases. CONCLUSIONS: The use of single allergens in the in vitro diagnosis of peach allergy by specific IgE determination, BAT, and CAST offers high specificity and sensitivity, with better results than the HRT.

Diagnosis of clavulanic acid allergy using basophil activation and leukotriene release by basophils.

Clavulanic acid is a potent inhibitor of B-lactamase that is increasingly prescribed in association with amoxicillin. We report 2 cases of patients who experienced pruritus, wheals, and angioedema after oral intake of amoxicillin/clavulanic acid. Routine skin tests for B-lactam antibiotics and specific immunoglobulin (Ig) E were negative in both patients. Analysis of CD63 expression by the basophil activation test (BAT) using flow cytometry and of sulphidoleukotriene (sLT) release by basophils using the cellular allergen stimulation test (CAST) revealed significant positive responses with amoxicillin/clavulanic acid and with clavulanic acid, and negative responses with amoxicillin and other beta-lactam antibiotics. In addition, cultured CD3+CD4+ cells showed a significant increase in the expression of CD69, CD25, and HLA-DR in the presence of clavulanic acid. Both patients tolerated therapeutic doses of amoxicillin. BAT and CAST are useful ex vivo procedures for the detection of specific IgE-mediated allergy to clavulanic acid, especially for patients with negative skin test results.

Health-related quality of life in allergic rhinitis: comparing the short form ESPRINT-15 and MiniRQLQ questionnaires.

BACKGROUND: We compared the psychometric properties of the ESPRINT-15, the short form of a new Spanish instrument to measure health-related quality of life in allergic rhinitis (AR) patients, with those of the Mini-Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ). METHODS: The questionnaires were compared in Spanish patients with intermittent allergic rhinitis (IAR) or persistent AR in a prospective, observational study. Floor and ceiling effects, internal consistency (Cronbach's alpha), test-retest reliability (intraclass correlation coefficient; ICC), convergent and known groups validity, and sensitivity to change (standardized response means; SRMs) were compared. RESULTS: In terms of content, while the MiniRQLQ has a dimension covering practical problems and places more emphasis on symptoms, the ESPRINT-15 has two dimensions (Sleep and Psychological impact) which are not included in the MiniRQLQ. In the validation study, 400 patients were included and 59% of the sample had persistent AR. There were no significant floor or ceiling effects on any dimension on either questionnaire. Cronbach's alpha values for the ESPRINT-15 and MiniRQLQ overall scores were 0.92 and 0.90, respectively. In 48 clinically stable patients, ICCs were 0.80 and 0.77, respectively. Both instruments discriminated between patients with IAR and persistent AR. Correlations with symptom scores and generic measures were moderate to strong. SRMs for overall scores and individual dimensions on the two questionnaires in the 197 patients reporting a change in health status ranged from 0.7 to 1.3. CONCLUSIONS: Both questionnaires performed well in psychometric terms. The ESPRINT-15 is particularly recommended for use in Spanish-speaking populations.

Two different profiles of peach allergy in the north of Spain.

BACKGROUND: Peach allergy has two different patterns: central Europe with oral allergy syndrome (OAS) related to a primary sensitization to birch pollen Bet v 1 and profilins and southern Europe with mostly systemic symptoms, in many cases due to sensitization to lipid-transfer proteins. METHODS: Thirty peach-allergic patients with positive skin and food challenge tests and 29 control subjects were included. Skin prick tests (SPT) with inhalant allergens, commercial peach and apple extracts and native Pru p 3 were performed. In vitro specific immunoglobulin (Ig) E to grass pollen, birch pollen, peach, apple, rBet v 1, rBet v 2 and rPhl p 12 was determined by CAP, and rBet v 1, rMal d 1, rMal d 4, rMal d 3 and rPru p 3 using the ADVIA-Centaur platform. Basophil activation test (BAT) with commercial peach extract, commercial apple extract, nPru p 3, rMal d 3, rMal d 1 and rMal d 4 was also performed. RESULTS: Pru p 3 was the major allergen in the patient group from northern Spain. Sensitization to this allergen was found in 100% of the patients with systemic symptoms or contact urticaria. Only 60% of OAS patients were sensitized to Pru p 3, being all of them sensitized to profilins and 60% of them to allergens of the Bet v 1 family. Specific IgE determination and BAT using recombinant allergens (rPru p 3) show specificity and sensitivity values close to 100%. CONCLUSIONS: Most peach-allergic patients coming from the north of Spain present systemic symptoms after ingestion of peach, Pru p 3 being the main allergen. Patients with OAS present profilin-Bet v 1-related sensitization. Thus, in the north of Spain our patients show a mixed central-south Europe pattern with LTP-profilin-Bet v 1 sensitization depending on the symptoms presented. The use of natural and recombinant plant allergens, allows establishing the sensitization patterns to the different allergens studied.

Specific IgG to Thermoactynomices vulgaris, Micropolyspora faeni and Aspergillus fumigatus in building workers exposed to esparto grass (plasterers) and in patients with esparto-induced hypersensitivity pneumonitis.

BACKGROUND: Esparto is one the most frequent causes of hypersensitivity pneumonitis in Spain. OBJECTIVE: Determination of risk factors in the working environment that could explain the sensitisation process, and assessment of the differences in specific IgG levels to Aspergillus fumigatus, Saccharopolyspora rectivirgula and Thermoactynomices vulgaris in patients with hypersensitivity pneumonitis induced by esparto, exposed healthy plasterers and control population. METHODS: Determination of precipitins and specific IgG to Aspergillusfumigatus, Saccharopolyspora rectivirgula and Thermoactynomices vulgaris in the three previously mentioned groups. Questionnaire on possible risk occupational and extra-occupational factors. RESULTS: Both healthy and exposed plasterers have higher levels of specific IgG to Aspergillus fumigatus, Saccharopolyspora rectivirgula and Thermoactynomices vulgaris than the healthy controls. The patients had higher levels of IgG than exposed healthy plasterers only to Thermoactynomices vulgaris. Precipitins were detected in only two patients. There were no occupational factors influencing on the sensitisation process. CONCLUSIONS: Specific IgG is an occupational exposure marker among plasterers, but it has not been possible to establish a cut off point that differentiates exposed subjects from affected ones. This determination has a greater sensitivity than precipitins. We did not identify occupational or extra-occupational risk factors that facilitate the sensitisation process.

Antigen specific quantification of sulfidoleukotrienes in patients allergic to Betalactam antibiotics.

BACKGROUND: After in vitro allergen-specific stimulation, basophils become activated and release sulfidoleukotrienes LTC4, LTD4 and LTE4. This can be detected by means of the CAST assay. We assessed the positivity criteria and the reliability of antigen-specific sulfidoleukotriene production (CAST) in the in vitro diagnosis of betalactam (BL) allergic patients. MATERIAL AND METHODS: We studied a sample of 67 patients (age 48.94 +/- 15.76 years) who had presented with anaphylaxis or urticaria-angioedema within the first 60 minutes after administration of Amoxicillin (54/67), Penicillin G (7/67), Cefuroxime (5/67) or Cefazoline (1/67). All of them had a positive skin test to at least one of the antigenic determinants of Penicillin. As control group 30 adults with negative skin tests who tolerated BL were included. All of them underwent skin tests, oral provocation tests, specific IgE (CAP-FEIA, Pharmacia) and CAST. RESULTS: Positivity criteria were established by means of ROC curves: a sLT release induced by Betalactams of at least 100 pg/ml and greater than or equal to 3 times the basal value. The overall sensitivity of CAST is 47.7% and specificity 83.3%. Sensitivity of specific IgE is 37.8% and specificity 83.3%. CONCLUSIONS: We have established validated positivity criteria for the CAST technique in patients allergic to Betalactams. This technique is a useful in vitro diagnostic method in patients with IgE-mediated allergy to Betalactam antibiotics.

The flow-cytometric determination of basophil activation induced by aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) is useful for in vitro diagnosis of the NSAID hypersensitivity syndrome.

BACKGROUND: Hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs), manifested by cutaneous symptoms and/or airway manifestations represent 20-25% of all hypersensitivity reactions to drugs. Today, it is still claimed that no in vitro diagnostic tests exist for that condition and that the only way to confirm the diagnosis is a provocation challenge. OBJECTIVE: The objective of this study was to assess whether NSAIDs may provoke blood basophil activation in vitro in such patients, as detected by a flowcytometric technique. METHODS: Sixty NSAID hypersensitive patients (38 with cutaneous, 20 with airway and two with cutaneous and airway symptoms) and 30 control patients (15 asthmatics) were selected. Their hypersensitivity was confirmed by documented history indicating at least two clinical episodes to two or more different NSAIDs or by positive oral provocation challenge. Isolated buffy coat leukocytes were stimulated in vitro with aspirin, paracetamol, metamizol, diclofenac, and naproxen. The percentage of activated basophils was evaluated by an anti-CD63. RESULTS: Aspirin showed a sensitivity of 43.3%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 99.4%. For the other NSAIDs, the sensitivity and specificity values were: for paracetamol 11.7% and 100%, for metamizol 15% and 100%, for diclofenac 43.3% and 93.3% and for naproxen 54.8% and 74.1%. When considering the first four NSAIDs, the global sensitivity raised to 63.3% and specificity to 93.3%. If the number of tests is to be limited for practical reasons, the combination of acetylsalicylic acid and diclofenac at two concentrations yields a sensitivity of 58.3% and a specificity of 93.3%. CONCLUSIONS: Flowcytometric determinations of basophil activation following stimulation with NSAIDs show a high sensitivity (60-70%) with specificity above 90%. So this test may help avoiding some cumbersome and dangerous provocation challenges.

Basophil activation and sulfidoleukotriene production in patients with immediate allergy to betalactam antibiotics and negative skin tests.

BACKGROUND: New in vitro diagnostic methods for IgE-mediated drug allergic reactions, such as basophil activation test and antigen specific sulfidoleukotriene test, have proven their usefulness in patients with positive skin tests. OBJECTIVE: To assess the usefulness of basophil activation test and antigen specific sulfidoleukotriene test in the diagnosis of patients with IgE-mediated allergy to Betalactam antibiotics and negative skin tests. METHODS: The 23 patients included in the study underwent basophil activation test, antigen specific sulfidoleukotriene test and specific IgE. The patients were classified into three groups. GROUP A: patients with positive specific IgE. GROUP B: patients with a unique immediate reaction to Betalactams, negative specific IgE and positive oral provocation tests. And Group C: patients with at least two immediate reactions induced by Betalactams and negative specific IgE. RESULTS: The sensitivity/specificity of the different tests are: basophil activation test 39.1 %/93.3%, antigen specific sulfidoleukotriene test 22.7%/83.3%, specific IgE 21.7%/86.7%. The joint use of the three tests allows diagnosis of 60.9% of the patients. CONCLUSION: In vitro diagnostic tests, especially basophil activation test, are very important tools in the diagnosis of patients with IgE-mediated allergy to Betalactams and negative skin tests, avoiding performance of potentially dangerous oral provocation tests in a high percentage of cases.

Use of CD63 expression as a marker of in vitro basophil activation and leukotriene determination in metamizol allergic patients.

BACKGROUND: We assessed the reliability of basophil activation test (FAST) and sulphidoleukotriene production (CAST) in the in vitro diagnosis of allergy to metamizol, evaluating its sensitivity and specificity. METHODS: Twenty-six patients allergic to metamizol and 30 control individuals were studied. Skin tests with metamizol, FAST, and CAST were performed. RESULTS: FAST sensitivity was 42.3% and specificity 100%. The PPV of FAST is 100% and the NPV 99.4%. The likelihood ratio for a positive value cannot be calculated because the specificity is 100% and the likelihood ratio for a negative value is 0.58. CAST sensitivity was 52%, and specificity 90%. The PPV of the test is 5% and the NPV 99.5%. The likelihood ratio for a positive result was 5.2 and that for a negative result 0.53. FAST detects a larger number of cases when patients are studied within the first 6 months after the clinical reaction (chi = 4.2, P = 0.04) than later. Together with skin tests, FAST allowed detection of 69.2% patients allergic to metamizol, the same as CAST 76%. The joint use of the three techniques allowed identification of 76.9% of cases. CONCLUSIONS: FAST and CAST are useful for the diagnosis of allergy to pyrazolones. Its usefulness clearly increases when recent reactions are studied.