LTT and HLA testing as diagnostic tools in Spanish vancomycin-induced DRESS cases: A case-control study.

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe T-cell-mediated off-target adverse reaction. DRESS cases caused by vancomycin have often been reported. The HLA-A*32:01 allele has been associated with genetic susceptibility to vancomycin-induced DRESS in US citizens of European descent. We have analyzed the association of the HLA-A*32:01 allele in 14 Spanish DRESS cases in which vancomycin was suspected as the culprit drug, and the lymphocyte transformation test (LTT) as an in vitro assay to evaluate vancomycin sensitization. The results were compared to vancomycin-tolerant control donors. LTT was performed in 12 DRESS cases with PBMCs from resolution samples available and in a group of 12 tolerant donors. ROC curves determined that LTT is a suitable tool to identify patients sensitized to vancomycin (AUC = 0.9646; p < 0.0001). When a stimulation index >3 was regarded as a positive result, contingency tables determined 91% sensitivity, 91.67% specificity, 91% positive predictive value, and 91.67% negative predictive value (p = 0.0001, Fisher's exact test). The HLA A*32:01 allele was determined by an allele-specific PCR assay in 14 cases and 25 tolerant controls. Among the DRESS cases, five carriers were identified (35.7%), while it was detected in only one (4%) of the tolerant donors, [odds ratio (OR) = 13.33; 95% CI: 1.364-130.3; p = 0.016]. The strength of the association increased when only cases with positive LTT to vancomycin were considered (OR = 24.0; 95% CI: 2.28-252.6; p = 4.0 × 10-3). Our results confirm the association of the risk allele HLA-A*32:01 with vancomycin-induced DRESS in Spanish cases, and support LTT as a reliable tool to determine vancomycin sensitization.

Characterization of hypersensitivity reactions to polysulfone hemodialysis membranes.

BACKGROUND: In recent years, cases have been reported in which unexpected systemic hypersensitivity reactions occurred in patients dialyzed with polysulfone- or polyethersulfone-biocompatible membranes in the absence of other risk factors. The pathomechanisms involved in these reactions are largely unknown. OBJECTIVE: To characterize hypersensitivity reactions to polysulfone hemodialysis using clinical and laboratory data and to identify biomarkers suitable for endotype identification and diagnosis. METHODS: We prospectively collected data from 29 patients with suspected hypersensitivity reactions to polysulfone hemodialysis membranes. Clinical laboratory parameters such as tryptase, blood cell counts, and complement levels were recorded. Acute samples were obtained from 18 cases for the ex vivo assessment of basophil activation by flow cytometry analysis of CD63, CD203, and FcεRI cell membrane expression. Serum cytokines and anaphylatoxin concentrations were evaluated in 16 cases by Luminex and cytometric bead array analysis. RESULTS: Tryptase was elevated during the acute reaction in 4 cases. Evidence of basophil activation was obtained in 10 patients. Complement activation was found in only 2 cases. However, C5a serum levels tended to increase during the acute reaction in those patients with hypoxemia. Significantly higher serum levels of interleukin-6 were observed during the acute reactions to polysulfone hemodialysis (P = .0103). CONCLUSION: Based on biomarker analysis, various endotypes were identified, including type I-like (with the involvement of mast cells or basophils), complement, and cytokine (interleukin-6) release-related reactions, with some patients showing mixed reactions. Further research is needed to unravel the exact mechanisms involved in the activation of these cellular and molecular pathways.

Prevalence and early-life risk factors of school-age allergic multimorbidity: The EuroPrevall-iFAAM birth cohort.

BACKGROUND: Coexistence of childhood asthma, eczema and allergic rhinitis is higher than can be expected by chance, suggesting a common mechanism. Data on allergic multimorbidity from a pan-European, population-based birth cohort study have been lacking. This study compares the prevalence and early-life risk factors of these diseases in European primary school children. METHODS: In the prospective multicentre observational EuroPrevall-iFAAM birth cohort study, we used standardized questionnaires on sociodemographics, medical history, parental allergies and lifestyle, and environmental exposures at birth, 12 and 24 months. At primary school age, parents answered ISAAC-based questions on current asthma, rhinitis and eczema. Allergic multimorbidity was defined as the coexistence of at least two of these. RESULTS: From 10,563 children recruited at birth in 8 study centres, we included data from 5,572 children (mean age 8.2 years; 51.8% boys). Prevalence estimates were as follows: asthma, 8.1%; allergic rhinitis, 13.3%; and eczema, 12.0%. Allergic multimorbidity was seen in 7.0% of the whole cohort, ranging from 1.2% (Athens, Greece) to 10.9% (Madrid, Spain). Risk factors for allergic multimorbidity, identified with AICc, included family-allergy-score, odds ratio (OR) 1.50 (95% CI 1.32-1.70) per standard deviation; early-life allergy symptoms, OR 2.72 (2.34-3.16) for each symptom; and caesarean birth, OR 1.35 (1.04-1.76). Female gender, OR 0.72 (0.58-0.90); older siblings, OR 0.79 (0.63-0.99); and day care, OR 0.81 (0.63-1.06) were protective factors. CONCLUSION: Allergic multimorbidity should be regarded as an important chronic childhood disease in Europe. Some of the associated early-life factors are modifiable and may be considered for prevention strategies.

Frequency of food allergy in school-aged children in eight European countries-The EuroPrevall-iFAAM birth cohort.

BACKGROUND: The prevalence of food allergy (FA) among European school children is poorly defined. Estimates have commonly been based on parent-reported symptoms. We aimed to estimate the frequency of FA and sensitization against food allergens in primary school children in eight European countries. METHODS: A follow-up assessment at age 6-10 years of a multicentre European birth cohort based was undertaken using an online parental questionnaire, clinical visits including structured interviews and skin prick tests (SPT). Children with suspected FA were scheduled for double-blind, placebo-controlled oral food challenges (DBPCFC). RESULTS: A total of 6105 children participated in this school-age follow-up (57.8% of 10 563 recruited at birth). For 982 of 6069 children (16.2%), parents reported adverse reactions after food consumption in the online questionnaire. Of 2288 children with parental face-to-face interviews and/or skin prick testing, 238 (10.4%) were eligible for a DBPCFC. Sixty-three foods were challenge-tested in 46 children. Twenty food challenges were positive in 17 children, including seven to hazelnut and three to peanut. Another seventy-one children were estimated to suffer FA among those who were eligible but refused DBPCFC. This yielded prevalence estimates for FA in school age between 1.4% (88 related to all 6105 participants of this follow-up) and 3.8% (88 related to 2289 with completed eligibility assessment). INTERPRETATION: In primary school children in eight European countries, the prevalence of FA was lower than expected even though parents of this cohort have become especially aware of allergic reactions to food. There was moderate variation between centres hampering valid regional comparisons.

Risk Factors for Hen's Egg Allergy in Europe: EuroPrevall Birth Cohort.

BACKGROUND: Hen's egg is one of the commonest causes of food allergy, but there are little data on its risk factors. OBJECTIVE: To assess the risk factors, particularly eczema, for hen's egg allergy in the EuroPrevall birth cohort. METHODS: In the pan-European EuroPrevall birth cohort, questionnaires were undertaken at 12 and 24 months or when parents reported symptoms. Children with suspected egg allergy were invited for skin prick testing, specific IgE assessment, and double-blind, placebo-controlled food challenge (DBPCFC) as indicated. Each egg allergy case (positive DBPCFC or egg-induced anaphylaxis) was allocated up to 2 age- and country-matched controls. RESULTS: A total of 12,049 infants were recruited into the EuroPrevall birth cohort, and 9,336 (77.5%) were followed until 2 years. A total of 86 infants had egg allergy (84 by DBPCFC) and were matched with 140 controls. Independently associated with egg allergy were past/current eczema (adjusted odds ratio, 9.21; 95% CI, 2.65-32.04), Scoring Atopic Dermatitis (1.54 per 5 units; 1.28-1.86), antibiotics in the first week of life (6.17; 1.42-26.89), and current rhinitis (3.02; 1.04-8.78). Increasing eczema severity was associated with an increasing likelihood of egg allergy. Eczema was reported to have started 3.6 (SE, 0.5) months before egg allergy. Age of introduction of egg into the diet was not associated with egg allergy. CONCLUSIONS: Similar to peanut allergy, eczema was strongly associated with egg allergy development and the association increased with increasing eczema severity. The age of introduction of dietary egg was not a risk factor. The potential role of antibiotics in early life as a risk factor for egg allergy needs further examination.

Lymphocyte Transformation Test (LTT) in Allergy to Benznidazole: A Promising Approach.

Benznidazole (Bzn) from the nitroimidazole family and nifurtimox from nitrofurans family, are drugs used as first and second line treatment for acute and chronic phases of Chagas disease (CD). Even though skin reactions are frequent, confirmed allergy to Bzn is rare, and there are few cases reported in the literature. Since CD treatment is very restrained, the possibility of cross-reactivity between members of the same and other pharmacological families highlights the importance of an adequate diagnosis that allows alternative treatments in CD and other diseases. We report a series of 31 patients (69% women) referred to our Allergy unit with suspected hypersensitivity to Bzn, twenty three of them with mild reactions and eight of them with severe reactions. LTT with Bzn was performed in 31 patients and in 8 negative controls. LTT was also performed in 25 and 20 of these patients with nifurtimox and Mtn, respectively. Twenty-one out of thirty-one patients were Bzn prick tested, and all were negative. We obtained 2/19 positive results on patch tests to Bzn. LTT with Bzn was positive in 22/31 patients (Sensitivity 75.9% and specificity 100%). The test was considered positive with a stimulation index ≥2. There was a positive result in 7/25 patients for nifurtimox and in 7/20 patients with Mtn. After negative LTT and skin tests, oral provocation was performed in 4/9 patients, all negative. LTT is a safe test that seems to be more useful than skin tests (prick and patch test), particularly in severe reactions, in confirming delayed hypersensitivity to Bzn and detecting cross reactivity with other imidazoles such as Mtn and reactivity to other drugs like nifurtimox. Tests for these drugs need to be included in the workup of patients with hypersensitivity to Bzn in case they are needed as an alternative treatment for CD or to treat other frequent infectious diseases.

[Delayed allergic reaction to furosemide with a positive lymphocyte transformation test]. / Reacción alérgica tardía a furosemida con positividad de la prueba de transformación de linfocitos.

BACKGROUND: Furosemide is the most commonly prescribed loop diuretic worldwide. Although, its extended use, furosemide rarely induces allergic reactions. Until 2013, only 49 cases of furosemide allergy had been described. CLINICAL CASE: We have reported on a patient who developed a delayed, erythematous and pruritic skin eruption after the ingestion of furosemide. The implication of furosemide in the reaction was established by a positive lymphocyte transformation test (LTT). CONCLUSION: This is the first reported case of hypersensitivity to furosemide in which this drug was confirmed as the trigger by a positive LTT. LTT could become a decent diagnostic alternative for patients who experience delayed reactions to furosemide.

Antecedentes: La furosemida es el diurético de asa más comúnmente prescrito en todo el mundo. A pesar de su amplio uso, rara vez induce reacciones alérgicas. Hasta 2013 solo se habían descrito 49 casos de alergia a la furosemida. Caso clínico: Mujer de 68 años con hipertensión tratada con amlodipina, así como rinoconjuntivitis alérgica. Después del consumo de 40 mg de furosemida por cinco días debido a edema bilateral maleolar presentó exantema cutáneo maculopapular, eritematoso y pruriginoso. Los resultados positivos en la prueba de transformación de linfocitos confirmaron la implicación de la furosemida en la reacción. Conclusión: El caso que se reporta es el primero de hipersensibilidad a la furosemida en el que se confirma la implicación del fármaco por medio de una prueba de transformación de linfocitos positiva, la cual podría convertirse en una alternativa diagnóstica para los pacientes que experimentan reacciones adversas tardías a la furosemida.

Alergia a antibióticos: perspectiva desde un hospital de tercer nivel / Allergy to antibiotics: Perspective from a tertiary care hospital

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[When education in asthma is crucial. About a case]. / Cuando la educación en asma es crucial. A propósito de un caso.

BACKGROUND: Childhood asthma causes frequent hospitalizations and visits to the emergency room because of exacerbations that could be avoided if the disease is managed properly. CLINICAL CASE: A 6-year-old girl who has had asthma since her first 16 months of life. She had been taken 130 times to the emergency room; she had been hospitalized 22 times, and she had received numerous medical consultations for asthma. She had never received structured health education, therefore, she was misusing the inhalation devices, and the controller treatment for bronchial inflammation was clearly below the dose according to the level of severity of the disease. There was an intervention focused on health education, an increase in the dose of anti-inflammatory drugs to treat bronchial asthma, and instruction in the proper use of inhaled medications. Since the intervention was made, the patient achieved better control without requiring visits to the emergency room, hospital admissions, or systemic corticosteroids after two years of follow-up. CONCLUSION: The lack of health education about asthma causes insufficient control of the disease. In the therapeutic approach to patients with severe uncontrolled asthma, it is essential to apply structured procedures of health education.

Antecedentes: El asma infantil ocasiona frecuentes hospitalizaciones y visitas a urgencias por exacerbaciones que podrían ser evitadas con el manejo apropiado de la enfermedad. Caso clínico: Niña de seis años con asma desde los 16 meses de vida. Fue llevada 130 veces al servicio de urgencia, 22 veces fue hospitalizada y recibió otras numerosas consultas médicas por asma. Nunca había recibido educación sanitaria estructuradamente, de manera que utilizaba los dispositivos de inhalación inadecuadamente y el tratamiento controlador de la inflamación bronquial estaba claramente por debajo de la dosis correspondiente al grado de gravedad de su asma. Se realizó una intervención centrada en la educación sanitaria, incremento de la dosis de medicamentos antiinflamatorios bronquiales e instrucción en el uso adecuado de la medicación inhalada. A partir de la intervención, la paciente alcanzó un mejor control sin requerir nuevamente visitas a urgencias, ingresos hospitalarios ni corticoides sistémicos, tras dos años de seguimiento. Conclusiones: La falta de educación sanitaria en asma ocasiona control insuficiente de la enfermedad. En el acercamiento terapéutico al paciente con asma grave no controlada resulta imprescindible aplicar procedimientos estructurados de educación sanitaria.

Aspirin desensitization in aspirin-exacerbated respiratory disease: New insights into the molecular mechanisms.

BACKGROUND: Aspirin desensitization (AD) has been the only available modifying treatment in aspirin-exacerbated respiratory disease (AERD). The mechanisms of AD are nonetheless poorly understood. Though very effective, AD is limited by its risks and side-effects. OBJECTIVE: Moving forward to the targeted biologicals era, the aim of this study was to characterize the airway inflammatory response to long-term AD, including TSLP dynamics, in order to assess potential new targets in AERD. PATIENTS AND METHODS: Adult patients with aspirin challenge-confirmed AERD underwent an oral AD followed by daily ingestion of aspirin for at least 6 months. Clinical data and inflammatory biomarkers were measured and compared, before and after AD. Induced sputum analyses were performed at baseline, one and six months after AD (differential cell count and levels of sputum supernatant leukotriene C4, prostaglandin D2 and E2, and TSLP). RESULTS: AD was followed by significant clinical improvement, as quantified by all monitored parameters. The good clinical outcomes of AD in our study are supported by overall changes observed in the arachidonic acid metabolites (decreased PGD2 over a constant LTC4/PGE2). TSLP increased (mean baseline 0.1 ±â€¯0.03; 1 month 3.68 ±â€¯7; 6 months 212.2 ±â€¯44 pg/ml; p < 0.01). CONCLUSIONS: Our findings suggest that new biologicals blocking TSLP might have a clinical benefit in AERD, by cutting down the TSLP-induced PGD2 generation.

Physician's appraisal vs documented signs and symptoms in the interpretation of food challenge tests: The EuroPrevall birth cohort.

BACKGROUND: Blinded food challenges are considered the current gold standard for the diagnosis of food allergies. We used data from a pan-European multicenter project to assess differences between study centers, aiming to identify the impact of subjective aspects for the interpretation of oral food challenges. METHODS: Nine study centers of the EuroPrevall birth cohort study about food allergy recruited 12 049 newborns and followed them for up to 30 months in regular intervals. Intensive training was conducted and every center visited to ensure similar handling of the protocols. Suspected food allergy was clinically evaluated by double-blind, placebo-controlled food challenges using a nine dose escalation protocol. The primary challenge outcomes based on physician's appraisal were compared to documented signs and symptoms. RESULTS: Of 839 challenges conducted, study centers confirmed food allergy in 15.6% to 53.6% of locally conducted challenges. Centers reported 0 to 16 positive placebo challenges. Worsening of eczema was the most common sign when challenged with placebo. Agreement between documented objective signs and the challenge outcome assigned by the physician was heterogeneous, with Cohen's kappa spanning from 0.42 to 0.84. CONCLUSIONS: These differences suggest that the comparison of food challenge outcomes between centers is difficult despite common protocols and training. We recommend detailed symptom assessment and documentation as well as objective sign-based challenge outcome algorithms to assure accuracy and comparability of blinded food challenges. Training and supervision of staff conducting food challenges is a mandatory component of reliable outcome data.

[Delayed allergic reaction to amlodipine with a positive lymphocyte transformation test]. / Reacción alérgica tardía a amlodipino con positividad de la prueba de transformación de linfocitos.

BACKGROUND: Amlodipine is one of the third generation dihydropyridine calcium channel blockers used for hypertension. Mild, moderate and severe reactions have been reported with calcium channel blockers. Cross-reactivity among these drugs has not been established. CLINICAL REPORT: We have presented the case of a patient who developed a delayed pruritic, and erythematous maculopapular skin exanthema after the intake of amlodipine. A positive lymphocyte transformation test (LTT) confirmed the implication of amlodipine in the reaction and showed positivity to another calcium channel blocker, nifedipine, demonstrating cross reactivity. CONCLUSION: This is the first reported case of hypersensitivity to amlodipine in which the involvement of the drug is confirmed by a positive TTL. TTL could become a good diagnostic alternative for patients who experience late reactions to amlodipine and possibly cross-reactivity with nifedipine.

Antecedentes: el amlodipino es uno de los bloqueadores de los canales de calcio de dihidropiridinas de tercera generación utilizado para la hipertensión. Se han notificado reacciones leves, moderadas y graves con bloqueadores de los canales de calcio. No se ha establecido la reactividad cruzada entre estos fármacos. Caso clínico: se presenta el caso de una paciente con exantema cutáneo maculopapular, eritematoso y pruriginoso tardío tras la ingestión de amlodipino. La prueba de transformación de linfocitos mostró positividad al amlodipino, lo que confirmó la implicación de este fármaco en la reacción; también mostró positividad al nifedipino, lo que demostró la presencia de reactividad cruzada. Conclusión: este es el primer caso reportado de hipersensibilidad a amlodipino en el que se confirma la implicación del fármaco por medio de una prueba positiva de transformación de linfocitos, la cual podría convertirse en una buena opción diagnóstica en aquellos pacientes que experimentan reacciones tardías al amlodipino, así como posible reactividad cruzada con nifedipino.

Mechanisms Involved in Hypersensitivity Reactions to Polysulfone Hemodialysis Membranes.

Several cases of patients with anaphylactic or systemic hypersensitivity reactions to polysulfone (PS) hemodialysis (HD) membranes and tolerance to cellulose triacetate (CTA) membranes have recently been reported. To investigate the mechanisms involved in PS hypersensitivity, basophil, T cell, and complement activation were analyzed in acute-phase samples from two patients with systemic reactions to PS-based membranes. Basophil and T cell activation, as well as higher serum tryptase levels were detected in acute-phase samples compared with basal levels. Complement levels (C3 and C4) were decreased in acute-phase samples from PS-allergic patients to a higher extent than in samples from control donors taken at the same time points, indicating complement activation during the acute reactions. An experimental external circuit was established on pediatric membranes after rinsing with low or high priming volumes of saline solution, to analyze basophils, T cells, and complement activation in blood samples from 10 PS-allergic and 8 nonallergic HD patients upon contact with PS-based or CTA membranes. Predialysis and postdialysis samples were collected. Basophils from PS-allergic patients exhibited increased degranulation, and T cells showed significantly increased activation after contact with PS-based membranes primed with low volumes of saline. No activation was detected in leukocytes from nonallergic patients under the same experimental conditions. Membrane priming with high volumes of saline abrogated activation of basophils and T cells. However, basophils from allergic donors showed significantly higher responses to Fcεc stimulation after contact with PS membranes. Basophil degranulation and elevated serum tryptase levels in allergic patients during acute reactions support the systemic activation of mast cells and basophils during hypersensitivity reactions to PS-based membranes. A leachable component of the membranes might be responsible for cell activation in some patients.

Significant HLA class I type associations with aromatic antiepileptic drug (AED)-induced SJS/TEN are different from those found for the same AED-induced DRESS in the Spanish population.

Aromatic antiepileptic drugs (AEDs) are among the drugs most frequently involved in severe cutaneous adverse reactions (SCARs), such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reactions with eosinophilia and systemic symptoms (DRESS). This study investigated the associations between the genetic polymorphisms of HLA class-I and AED-induced SCARs in the Spanish population. HLA class-I genotypes were determined in AED (phenytoin[PHT],lamotrigine[LTG],carbamazepine[CBZ],phenobarbital[PB])-induced SJS/TEN (n=15) or DRESS (n=12) cases included in the Spanish SCAR registry, PIELenRed. There were 3 control groups: (A)tolerant to a single AED, (B)tolerant to any AED, and (C)Spanish population controls. For SJS/TEN, concomitant HLA-A*02:01/Cw15:02 alleles were significantly associated with PHT-cases compared to control groups B and C [(B)odds ratio(OR):14.75, p=0.009;(C)OR:27.50, p<0.001], and were close to significance with respect to control group A (p=0.060). The genotype frequency of the HLA-B*38:01 was significantly associated with PHT-LTG-cases compared with the 3 groups of controls [(A)OR:12.86, p=0.012;(B)OR:13.81; p=0.002;(C)OR:14.35, p<0.001], and with LTG-cases [(A)OR:147.00, p=0.001;(B)OR:115.00, p<0.001;(C)OR:124.70, p<0.001]. We found the HLA-B*15:02 allele in a Spanish Romani patient with a CBZ-case. The HLA-A*11:01 was significantly associated with CBZ-cases [(A)OR:63.89, p=0.002;(B)OR:36.33, p=0.005;(C)OR:28.29, p=0.007]. For DRESS, the HLA-A*24:02 genotype frequency was statistically significant in the PHT-LTG-cases [(A)OR:22.56, p=0.003;(B)OR:23.50. p=0.001; (C)OR:33.25, p<0.001], and in the LTG-cases [(A),OR:49.00, p=0.015;(B)OR:27.77, p=0.005; (C)OR:34.53, p=0.002]. HLA-A*31:01 was significantly associated with the CBZ-cases [(A)OR:22.00, p=0.047;(B)OR:29.50, p=0.033;(C)OR:35.14, p=0.006]. In conclusion, we identified several significant genetic risk factors for the first time in the Spanish Caucasian population: HLA-A*02:01/Cw*15:02 combination as a risk factor for PHT-induced SJS/TEN, HLA-B*38:01 for LTG- and PHT- induced SJS/TEN, HLA-A*11:01 for CBZ-induced SJS/TEN, and HLA-A*24:02 for LTG- and PHT- induced DRESS. The strong association between HLA*31:01 and CBZ-DRESS in Europeans was confirmed in this study.