[Allergen immunotherapy for rare allergens]. / Allergen-Immuntherapie gegen seltenere Allergene.

Among allergies to aeroallergens, approximately 20% are allotted to the so-called rare allergens. These include ash pollen, weed pollen, storage mites, molds, and animal allergens. The prevalences of allergies to these allergens are lower, but affected patients also suffer considerably from their "rare" allergy. Hence, these allergies should neither be overseen nor completely forgotten in daily practice. Especially mold, mite, and animal allergens often induce asthma, so that the significance of allergen-specific immunotherapy (AIT) should not be neglected in causal therapy. This work summarizes the current state of knowledge on the groups of rare aeroallergens in terms of characteristics, prevalences, and data on AIT. It is based on a systematic literature search performed in the MEDLINE (PubMed®) and Google Scholar databases. AIT preparations for rare allergens are classified as individual formulations and are not subject to the German Therapy Allergen Ordinance. Due to the low case numbers, the levels of evidence for these formulations are not as high as those for dust mites, grass, or birch pollen, but exhibit good efficacy in practical experience.

Elevated aluminum excretion in patients by long-term subcutaneous immunotherapy - A cross-sectional case-control study.

BACKGROUND: Aluminum (Al) adjuvants have been used in vaccines and subcutaneous immunotherapy (SCIT) for decades. Despite indisputable neurotoxic properties of Al, there is no clear evidence of a causal relationship between their use and any neurotoxic side effects. However, recent rat studies have shown an accumulation of Al from adjuvants in tissues, especially in bones. OBJECTIVES: Since the human toxicokinetics of Al-adjuvants are poorly understood, this study aimed to evaluate whether up-dosed or long-term SCIT with Al-coupled extracts leads to increased Al load in humans. METHODS: This observational cross-sectional case-control study explored Al excretion in hymenoptera venom allergy patients recruited in 2020 before initiation (n = 10) and during ongoing (n = 12) SCIT with Al-based preparations. Urine samples were collected before and 24 h after the SCIT injections and analyzed for aluminum content by using atomic absorption spectrometry. The cumulative administered Al dose was extracted from patient records. Patients receiving long-term immunotherapy were treated between 2.8 and 13.6 years (mean 7.1). Other potential sources of Al exposure were surveyed. RESULTS: Patients who had received Al-coupled immunotherapy for several years showed significantly (p < 0.001) higher Al excretion than the controls at initiation of immunotherapy (mean 18.2 µg/gC vs. 7.9 µg/gC) and predominantly (73%) were above the 95th percentile of the general populations' exposure (>15 µg/gC), however, without reaching levels of toxicological concern (>50 µg/gC). Taking both groups together excreted Al levels correlated with the cumulative administered Al dose from SCIT (linear regression: Alurine = 8.258 + 0.133*Alcum; p = 0.001). DISCUSSION: These results suggest a relevant iatrogenic contribution of long-term SCIT to human internal Al burden and potential accumulation. Considering the medical benefits of Al-adjuvants and SCIT a differentiated risk-benefit analysis is needed. For certain scenarios of potential toxicological concern in clinical practice biomonitoring might be advisable.

Assessing IgE sensitization profiles to birch and timothy grass pollen allergens in birch pollen allergic blood donors using an oligoplex specific IgE assay.

IgE sensitization profiles to single birch allergens in birch-sensitized patients differ among European countries. The aim of this study was to determine the distribution of specific IgE antibodies to major and minor birch pollen allergens in a population of allergic Norwegian individuals by using a birch allergic blood donor population as a surrogate sample. Sixty blood donors were recruited and sampled based on birch allergy symptoms such as rhinitis, rhinoconjunctivitis and/or mild asthma in previous seasons. All sera were collected before start of the pollen season and tested using a line blot assay (Euroimmun AG, Lübeck, Germany) for IgE to birch and timothy pollen. Both extracts, single allergens, and cross-reacting carbohydrate determinants (CCD) were analysed. Only donors with specific IgE to birch and/or timothy grass were further evaluated. Specific IgE to birch pollen extract was found in 52 sera, and sensitization to timothy grass in 40 sera. Specific IgE to Bet v 1 was predominant in contrast to Bet v 4 which was absent. However, sensitization to the minor allergens Bet v 2 and 6 was always found together with high levels of IgE to Bet v 1. Subjects sensitized to the profilin Bet v 2 from birch were also sensitized to Phl p 12 from timothy grass. In conclusion, there was predominantly Bet v 1 sensitization in this cohort and low sensitization to minor allergens and cross-reactive allergens (Bet v 2, Bet v 4, Phl p 7 and Phl p 12).

Randomized, Double-Blind, Placebo-Controlled Trial of Vitamin D Supplementation in the Build-up Phase of House Dust Mite-Specific Immunotherapy.

PURPOSE: Vitamin D (VitD) is an immunomodulatory molecule capable of alleviating allergic symptoms. However, the effectiveness of allergen-specific immunotherapy (AIT) is not commonly evidenced in the early build-up phase. The aim of the study was to determine the potential of VitD supplementation in this treatment phase. METHODS: Thirty-four house dust mite (HDM)-allergic adult patients treated with subcutaneous AIT were randomized to receive VitD2 60,000 IU/week or placebo for 10 weeks and followed up for 10 weeks. The primary endpoints were the symptom-medication score (SMS) and the treatment response rate. The secondary endpoints were eosinophil count and levels of plasma IL-10, Der p 2-specific IgG4, and dysfunctional regulatory T (CRTH2+ Treg) cells. RESULTS: Of 34 patients, 15 in each group completed the study. Patients with VitD deficiency receiving a VitD supplement showed significantly lower mean change SMS than the placebo group in weeks 10 (mean difference -54.54%, P = 0.007) and 20 (mean difference -42.69%, P = 0.04). The percentage of treatment responders reached 78% and 50% in the VitD and placebo groups, respectively, and the effect remained in week 20 (89% and 60%). No significant difference was observed for the tested immunological read-outs, with the exception of the frequency of CRTH2+ Treg cells, which was remarkably reduced in the VitD-treated patients. Moreover, improvement in SMS was correlated to the number of CRTH2+ Treg cells. Our in vitro experiment indicated that VitD downregulated activation markers, whereas it improved the function of CRTH2+ Treg cells. CONCLUSIONS: VitD supplementation in the build-up phase of AIT could relieve symptoms and decrease Treg cell dysfunction, especially in patients with VitD deficiency.

The Efficacy of a New Protocol of Oral Immunotherapy to Wheat for Desensitization and Induction of Tolerance.

Oral immunotherapy (OIT) is a novel approach to desensitization and tolerance induction in food allergy patients. This study aimed to design and implement a new wheat OIT protocol, evaluate its efficacy in tolerance induction, and assess specific immunoglobulin-E (IgE) and regulatory T cell changes. From 2015 to 2017, 26 patients with confirmed IgE-mediated hypersensitivity to wheat were treated via oral immunotherapy (OIT). Patients with prior anaphylactic episodes underwent OIT using the rush method. Specific IgE concentrations and the number of regulatory T cells (CD4+ CD25+ FOXP3+ T cells) were measured using Allergy Screen immunoblot assay and flow cytometry, respectively. This study was registered in the Iranian Registry of Clinical Trials (IRCT20181220042066N1). The results revealed success rates of 100% and 93.3% for desensitization and tolerance. Specific IgE was significantly reduced after 12 months of OIT. No significant change in regulatory T cell numbers was observed. In view of the promising findings of this study, the proposed OIT protocol could be viewed as an effective and valuable method to induce tolerance and desensitization in wheat allergic patients.

Recent Advances in Allergen-Specific Immunotherapy in Humans: A Systematic Review.

Allergen-specific immunotherapy (AIT) is presumed to modulate the natural course of allergic disease by inducing immune tolerance. However, conventional AITs, such as subcutaneous immunotherapy and sublingual immunotherapy, require long treatment durations and often provoke local or systemic hypersensitivity reactions. Therefore, only <5% of allergy patients receive AIT as second-line therapy. Novel administration routes, such as intralymphatic, intradermal and epicutaneous immunotherapies, and synthetic recombinant allergen preparations have been evaluated to overcome these limitations. We will review the updated views of diverse AIT methods, and discuss the limitations and opportunities of the AITs for the treatment of allergic diseases in humans.

Reacciones de hipersensibilidad a alglucosidasa alfa en enfermedad de Pompe: dos casos de desensibilización exitosa / Hypersensitivity reactions to alglucosidase alfa in Pompe disease: two cases of successful desensitization

La enfermedad de Pompe es un desorden neuromuscular autosómico recesivo de baja prevalencia, causado por la deficiencia total o parcial de la enzima alfa glucosidasa ácida (GAA), cuya única terapia de reemplazo enzimático disponible es la alglucosidasa alfa recombinante. Las reacciones adversas asociadas a la infusión se presentan con frecuencia. Se reportan dos casos de desensibilización exitosa con alglucosidasa alfa utilizando protocolos con dosis meta de 20 mg/kg, administrados quincenalmente; el primero de ellos, en una niña con historia de reacción adversa grave a los 15 meses de edad, en quien se utilizó un esquema con una dilución inicial de 1/10.000.000 de 28 pasos y una duración total de 13,1 horas. En el segundo caso, la paciente tuvo una reacción adversa grave a los 4 años de edad, se utilizó el protocolo de 22 pasos, concentración inicial de 1/1.000.000 y duración total de 7,2 horas. Se concluye que en pacientes con enfermedad de Pompe que presentan reacciones adversas durante la terapia de reemplazo enzimático, es posible realizar la desensibilización cada dos semanas con la dosis estándar de 20 mg/kg de forma exitosa, y progresivamente lograr la administración usual de la infusión

Pompe disease is a low prevalence autosomal recessive neuromuscular disorder, caused by total or partial deficiency of the acid alpha-glucosidase (GAA) enzyme, and its only available enzyme replacement therapy is the recombinant alglucosidase alfa. Infusion-associated adverse reactions occur frequently. Two cases of successful desensitization with alglucosidase alfa using protocols with a target dose of 20 mg/kg administered biweekly are reported; the first was a girl who had a history of serious adverse reaction at the age of 15 months, and undergone to a scheme with an initial dilution of 1/10,000,000 with 28 steps and a total duration of 13.1 hours. In the second case, the patient had a severe adverse reaction at the age of 4 years, a 22-step protocol was used with an initial concentration of 1/1,000,000 and a total duration of 7.2 hours. In conclusion, in patients with Pompe disease who presented adverse reactions during enzyme replacement therapy with alglucosidase alfa, it is possible to perform desensitization every two weeks with the standard dose of 20 mg/kg, and progressively achieve the usual administration of the infusion

Inmunoterapia oral con huevo en un hospital comarcal / Oral immunotherapy with egg in a regional hospital

Introducción y objetivos. La inmunoterapia oral (ITO) es una alternativa a la dieta de evitación en algunas alergias alimentarias. El objetivo de este trabajo es evaluar la eficacia y seguridad de la ITO con huevo en una consulta de alergia pediátrica. Material y métodos. Estudio observacional, longitudinal y retrospectivo de pacientes pediátricos con alergia al huevo persistente sometidos a ITO. Para la inducción se utilizó proteína de clara de huevo deshidratada administrada diariamente y con incrementos semanales hasta alcanzar una dosis de 4 gramos. Para la fase de mantenimiento se indicó una ingesta de al menos dos o tres huevos a la semana. Resultados. Se trataron 14 pacientes (6 niñas), de entre 5 y 13 años (mediana 5,5 años). Se consiguió desensibilización completa al final de la inducción en 11 pacientes (78,6%), que se mantuvo en todos ellos tras una mediana de tiempo de seguimiento de 29 meses. Durante la inducción los síntomas más frecuentes fueron: prurito orofaríngeo (9/14), dolor abdominal (7/14) y rinoconjuntivitis (6/14). Se emplearon antihistamínicos en 8 casos (57,1%) y ninguno precisó adrenalina. Entre los pacientes que consiguieron desensibilización se observó una tendencia al descenso de las IgE específicas, siendo estadísticamente significativo para las IgE a huevo completo (p = 0,047), clara de huevo (p = 0,031) y ovoalbúmina (p = 0,016). Conclusiones. La ITO con clara de huevo deshidratada resultó ser un tratamiento muy eficaz y bien tolerado en población pediátrica con alergia al huevo (AU)

Background and objective. Oral immunotherapy (OIT) is an alternative to strict avoidance for the management of some food allergies. The aim of this study is to assess the efficacy and safety of egg OIT in a paediatric allergy outpatient service. Methods. Retrospective, longitudinal observational study in children with persistent hen egg allergy who received egg OIT. For the build-up phase, dehydrated egg white was used daily. Updosing was performed weekly at the allergy unit, up to a final dose of 4 grams. Maintenance phase was carried out with a daily intake of one egg at least two or three times a week. Results. 14 patients (6 girls), whose ages ranged from 5 to 13 years (median 5.5 years) were treated with egg OIT. Eleven subject (78.6%) reached total desensitization, and all of them remained desensitized after a median follow-up time of 29 months. The most frequent adverse effects detected during the build-up phase were: oropharyngeal pruritus (9/14), abdominal pain (7/14), and rhinoconjuntivitis (6/14). Eight patients (57.1%) required oral antihistamines, and none received adrenaline. In those subjects that reached total desensitization, a trend to lower specific IgE levels was observed. That trends were statistically significand for whole egg (p = 0.047), egg white (p = 0.031), and ovalbumin (p = 0.016). Conclusions. Egg OIT was an effective and well tolerated treatment in children with egg allergY (AU)

Efficacy of Subcutaneous and Sublingual Immunotherapy for House Dust Mite Allergy: A Network Meta-Analysis-Based Comparison.

BACKGROUND: Meta-analyses comparing the efficacy of sublingual immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT) for house dust mite allergy are lacking. OBJECTIVE: To compare the efficacy of SLIT drops, SLIT tablets, and SCIT in patients with perennial allergic rhinitis through network analysis. METHODS: Frequentist network meta-analyses estimated the standardized mean difference (SMD) across the three immunotherapy modalities on allergic rhinitis symptom and medication score data from double-blind randomized clinical trials. Random effects models were investigated. RESULTS: We included 26 double-blind randomized clinical trials in this meta-analysis for the symptom score and 18 for the medication score. In the direct pairwise meta-analysis, a significant reduction of the symptom score was observed for all immunotherapy modalities compared with the placebo: pooled SMDs of -0.461 (95% confidence interval [CI], -0.795 to -0.127) for SLIT drop, -0.329 (95% CI, -0.426 to -0.231) for SLIT tablet, and -1.669 (95% CI, -2.753 to -0.585) for SCIT. For the medication score, a significant reduction was observed for all modalities. In network meta-analysis, the clinical efficacy of SCIT based on the symptom score was greater than for SLIT drop or SLIT tablet (SMD: -0.697, 95% CI, -1.105 to -0.288; and SMD: -0.819, 95% CI, -1.242 to -0.397). However, there was no significant difference in the symptom score between SLIT drop and SLIT tablet. CONCLUSIONS: This study demonstrated the clinical efficacy of all house dust mite immunotherapy modalities and suggests that SCIT may be more effective than SLIT drops or tablets in controlling symptoms of allergic rhinitis.

Reintroduction of Antituberculous Drugs in Patients with Antituberculous Drug-Related Drug Reaction with Eosinophilia and Systemic Symptoms.

BACKGROUND: Patients who suffered drug reaction with eosinophilia and systemic symptom (DRESS) during the treatment of tuberculosis (TB) commonly experience multidrug hypersensitivity reactions resulting in limited anti-TB drug choices. Therefore, reintroduction based on a desensitization protocol may be an option to resume anti-TB medication. OBJECTIVE: To evaluate the outcomes and safety of resuming anti-TB drugs according to reintroduction methods in patients with anti-TB drug-related DRESS. METHODS: A retrospective cohort of patients who had experienced anti-TB drug-related severe cutaneous adverse reactions from 2011 to 2017 was established from separate 5 institutions. RESULTS: Anti-TB medication was resumed in 27 of 29 patients with anti-TB drug-related DRESS through complete changing regimen (n = 9), reintroduction by a graded challenge (n = 5), or reintroduction using a desensitization protocol (n = 13). Nine patients completely changed their anti-TB regimen to second-line TB drugs, but only 1 (11.1%) succeeded in maintaining new anti-TB drugs. The other 8 failed to take drugs due to the occurrence of hypersensitivity reactions to the newly introduced anti-TB drugs. Two (40.0%) of 5 patients who underwent graded rechallenges successfully completed anti-TB drugs, whereas 3 (60%) failed to resume anti-TB drugs due to the recurrence of hypersensitivity reactions. In 13 patients who resumed anti-TB drugs using a desensitization protocol, no one who underwent desensitization developed recurrence of DRESS; 11 (84.6%) eventually completed anti-TB treatment and 2 eventually failed to complete anti-TB treatment due to late-onset itching and drug-induced liver injury. CONCLUSIONS: Resuming anti-TB medication based on desensitization protocols may be a safe and effective option for those with anti-TB drug-related DRESS.

Posicionamento da Associação Brasileira de Alergia e Imunologia sobre o manejo da imunoterapia específica com alérgenos (ITA) em pacientes vacinados contra COVID­19 / Position statement of the Brazilian Association of Allergy and Immunology on the management of allergen-specific immunotherapy (AIT) in patients vaccinated against COVID­19

A pandemia de COVID-19 representa um grande desafio para todas as especialidades médicas. A imunoterapia com alérgenos (ITA) é considerada o único procedimento terapêutico capaz de modificar a história natural das doenças alérgicas, e caracteriza o estado da arte na área de Alergia e Imunologia. Esta estratégia terapêutica de imunomodulação é capaz de promover a remissão e controle das doenças alérgicas por períodos prolongados, mesmo após o seu término. Existem poucos dados em relação ao emprego da ITA em pacientes vacinados contra COVID-19, e até o momento não há um posicionamento oficial das sociedades internacionais da área de Alergia e Imunologia Clínica. Este documento tem como objetivo estabelecer recomendações práticas para o manejo da ITA em pacientes que receberam a vacina contra COVID-19. Os fenômenos imunológicos envolvidos na imunoprofilaxia vacinal e no mecanismo de ação da ITA foram comparados, proporcionando o estabelecimento de recomendações precisas.

The COVID-19 pandemic represents a serious challenge for all medical specialties. Allergen-specific immunotherapy (AIT) is considered the only therapeutic procedure capable of modifying the natural history of allergic diseases and characterizes the state of the art in the field of allergy and immunology. This therapeutic strategy of immunomodulation is able to promote remission and control of allergic diseases for prolonged periods, even after cessation. There are few data regarding use of AIT in patients vaccinated against COVID-19 and, to date, there is no official position statement published by international allergy and clinical immunology societies. This document aims to establish practical recommendations for the management of AIT in patients who have received the COVID-19 vaccine. The immunological mechanisms involved in immunoprophylaxis with vaccines and the mechanism of action of AIT have been compared to provide a solid basis for establishing precise recommendations.

Is There a Role for Desensitization in Intestinal Transplantation?

Human leukocyte antigen allosensitization prior to transplant can increase the risk of early graft loss and prolong waitlist times for intestinal transplant candidates. Desensitization offers a potential therapeutic option to reduce the quantity of preformed antibodies prior to organ allocation and facilitate transplantation with a more immunologically compatible donor allograft. However, there remains a paucity of data to guide the use of desensitization in the setting of intestinal transplantation. As a result, in this review we evaluate the existing literature supporting the role of desensitization therapy in intestinal transplant, describe our own experience with the implementation of a risk-stratified desensitization protocol, and finally explore barriers and unanswered questions that continue to limit the widespread adoption of desensitization as a management strategy for highly sensitized intestinal transplant candidates.

Segurança da vacina de febre amarela em pacientes comprovadamente alérgicos à proteína do ovo / Safety of yellow fever vaccine in egg allergic patients

Introdução: A vacina de febre amarela, recomendada em áreas endêmicas, é contraindicada em alérgicos à proteína do ovo (APO) por ser cultivada em ovos de galinha embrionados. Objetivo: O objetivo do estudo foi mostrar a segurança da vacina de febre amarela em pacientes comprovadamente APO. Método: Foi realizado estudo prospectivo em hospital quaternário, no período de janeiro a outubro de 2018. Foram incluídos pacientes com APO confirmada por teste de provocação oral (TPO), reação anafilática à proteína do ovo nos últimos 6 meses, ou reação de APO nos últimos 2 meses associada à IgE específica positiva. Todos foram submetidos ao teste de puntura com a vacina na apresentação pura. Se negativo, realizado teste intradérmico (ID) com a vacina na diluição de 1:100. Se ID negativo, vacina aplicada em dose plena. Se teste de puntura ou ID positivo, vacina aplicada fracionada segundo protocolo de dessensibilização. Resultados: Dos 78 pacientes com história presumida de APO, confirmou-se o diagnóstico em 43 (30M:13F, mediana idade 2,7 a): 30 por TPO, 7 com anafilaxia em menos de 6 meses da vacina, e 6 com reação imediata após ingestão do ovo há menos de 2 meses e IgE específica positiva. Durante o TPO, 12 apresentaram anafilaxia, e os demais (18) apresentaram urticária e/ou angioedema ou vômitos. Todos os testes de puntura (43) foram negativos. ID foi negativo em 37 pacientes, que receberam a dose plena da vacina, sem reações. Apenas 6 apresentaram ID positivo e necessitaram dessensibilização para vacina. Metade desses pacientes (3/6) apresentou reações de hipersensibilidade leves e foi tratada com anti-H1 e/ou corticoide oral. O ID positivo foi significativamente relacionado à reação à vacina (p = 0,0016). Conclusão: Concluiuse ser possível vacinar alérgicos a ovo, com um protocolo seguro, mesmo em paciente comprovadamente anafilático. É necessária uma unidade especializada para sua realização, com capacidade de controlar possíveis situações de risco.

Introduction: The yellow fever vaccine (YFV) is recommended in endemic areas, but represents a risk for egg allergic (EA) patients, as it is cultivated in chicken embryos. Objective: This study aimed to describe the outcomes of YFV in patients with confirmed egg allergy. Methods: A prospective study was conducted in a quaternary hospital, from January to October 2018. EA was diagnosed through oral food challenge (OFC) or recent history of anaphylaxis following egg contact in the past 6 months or allergic reaction in the past 2 months with positive specific immunoglobulin E (IgE). Skin prick testing (SPT) with YFV was performed in all participants. If SPT was negative, an intradermal test (IDT) was performed at 1:100 dilution. If IDT was negative, a full dose of YFV was administered. If SPT was positive, the YFV was administered using a graded-dose protocol. Results: Among 78 patients with prior history of EA, 43 were confirmed (30 male to 13 female, median age of 2.7 years). Thirty patients had a positive OFC, seven reported recent anaphylaxis, and six had reactions in the past 2 months with positive specific IgE. During OFC, 12 patients had anaphylaxis and 18 had urticaria and/or angioedema or vomiting. SPT with YFV was negative in all patients (43). IDT was negative in 37 patients, who received a full dose of YFV, uneventfully. Six patients had a positive IDT and received the YFV in graded doses; half of them had a mild reaction controlled with antihistamines and three patients received the vaccine without reactions. Positive IDT was significantly related to vaccine reaction (p=0.0016). Conclusion: The YFV using a specific protocol was safe even in anaphylactic patients. An appropriate setting is required in order to control possible adverse events.

A case of rapid desensitization for rituximab-induced delayed hypersensitivity reaction

Rituximab is a monoclonal antibody used for the treatment of B-cell malignancies, including diffuse large B-cell lymphoma. Infusion-related hypersensitivity reactions to rituximab is well known, and delayed hypersensitivity reactions to rituximab are also reported. Desensitization is commonly used to prevent immediate hypersensitivity reactions, but recently there have been cases of successful desensitization therapy for delayed hypersensitivity reactions. A 66-year-old patient who underwent rituximab treatment for diffuse large B-cell lymphoma showed repeated rituximab-induced delayed hypersensitivity reactions with whole body rashes. Intravenous rapid desensitization was performed by using a 1-bottle, 11-step protocol for 6 cycles and thereafter hypersensitivity reaction did not recur. We herein reported a case of delayed hypersensitivity reaction caused by rituximab, which was successfully desensitized using our 11-step protocol.

Successful rapid subcutaneous desensitization to anakinra in a case with a severe immediate-type hypersensitivity reaction.

Summary: Anakinra, one of the novel biological agents, is a recombinant human IL-1 receptor antagonist. It is preferred as an alternative drug for familial Mediterranean fever cases where colchicine is not sufficient or cannot be used due to its side effects. Like all other biologics, hypersensitivity reactions to anakinra are quite rare. This is the first case which was successfully desensitized with anakinra after a severe immediate-type hypersensitivity reaction.

Incidência aumentada de haplótipo de HLA de classe II na anafilaxia grave secundária à carboplatina / Increased incidence of a class II HLA haplotype in severe anaphylaxis secondary to carboplatin

Objetivo: O papel de biomarcadores nas reações de hipersensibilidade a platinas tem sido estudado, e é conhecido que a presença da mutação do gene BRCA1/2 é fator de risco para reações de hipersensibilidade à carboplatina. A genotipagem de HLA de classes I e II auxilia na identificação de pacientes de risco para reações IgE-mediadas e mediadas por linfócitos T associadas a beta-lactâmicos e abacavir, respectivamente. Não são conhecidos alelos ou haplótipos de HLA mais prevalentes em pacientes alérgicos à carboplatina. O objetivo principal do estudo foi avaliar se alelos específicos de HLA de classe II são mais prevalentes em pacientes alérgicos à carboplatina submetidos à dessensibilização (DS). Método: Genotipagem de HLA de classe II realizada em 11 pacientes portadoras de neoplasias malignas tubo-ovarianas, alérgicas à carboplatina, e submetidas à DS, e em 12 pacientes tolerantes à carboplatina, por no mínimo oito ciclos. Analisou-se também a prevalência da mutação BRCA1/2 nos dois grupos estudados. Resultados: O alelo HLA-DRB1*15:01 foi mais prevalente entre as pacientes alérgicas (5/11; 45%) do que nos controles (1/12; 8,3%) (p = 0,06). O haplótipo de classe II DQA1*01:02-DQB1*06:02-DRB1*15:01 foi mais expresso no grupo de pacientes alérgicas. A mutação do BRCA1/2 mostrou-se mais prevalente no grupo alérgico. Conclusões: A identificação de pacientes de risco para reações alérgicas à carboplatina é de extrema importância com o uso crescente da medicação. A genotipagem de HLA e a pesquisa da mutação BRCA1/2 mostramse ferramentas promissoras que podem aumentar a segurança durante infusão regular de carboplatina e DS.

Objective: The role of biomarkers in hypersensitivity reactions (HSR) to platinum compounds has been studied, and the presence of BRCA1/2 gene mutation is known to be a risk factor for carboplatin HSR. Class I and II HLA genotyping helps identify patients at risk for IgE-mediated and T lymphocyte-mediated reactions associated with beta-lactams and abacavir, respectively. Associations between HLA alleles or haplotypes and carboplatin HSR are not known. The main objective of the present study was to evaluate whether specific class II HLA alleles are more prevalent in patients allergic to carboplatin who underwent rapid drug desensitization (RDD). Methods: Class II HLA genotyping was performed in 11 carboplatin-allergic patients with tubo-ovarian malignancies who were submitted to RDD, and in 12 patients who tolerated carboplatin, for at least eight cycles. The prevalence of the BRCA1/2 mutation was also analyzed in both groups. Results: The HLA-DRB1*15:01 allele was more prevalent among allergic patients (5/11; 45%) than in controls (1/12; 8.3%) (p = 0.06). Class II haplotype DQA1*01:02-DQB1*06:02-DRB1*15:01 and the BRCA1/2 mutation were also more prevalent in the allergic group. Conclusions: The identification of patients at risk for carboplatin HSR is of utmost importance, as the use of this medication is increasing. HLA genotyping and screening for the BRCA1/2 mutation are promising tools that may increase safety during regular carboplatin infusion and RDD.

Cow's Milk Desensitization in Anaphylactic Patients: A New Personalized-dose Method.

Cow's milk allergy (CMA) is the most frequent food allergy in children and oral immunotherapy (OIT) is a promising approach for treatment of patients. The most challenging cases are anaphylactic with coexisting asthma and proposing safe protocols is crucial especially in high risk groups. Considering that CMA varies among patients, an individualized OIT protocol would be beneficial to achieve a safer and more efficient method of desensitization. 18 children more than 3 years of age with IgE-mediated CMA were enrolled. CMA was confirmed by positive skin prick test (SPT) and positive oral food challenge (OFC) and 60% of individuals had a convincing history of persistent asthma. SPT with milk extracts, whole fresh milk and serially diluted milk concentrations were performed.  The dilution of milk that induced 3-5 mm of wheal in each individual was selected as the starting dilution for OIT. Desensitization began by 1 drop of the defined dilution and continued increasingly. Overall, 16 out of 18 children (88.8%) achieved the daily intake of 120 mL of milk. Four out of these 16 children accomplished the protocol without any adverse allergic reactions. 12 patients experienced mild to severe reactions. Wheal and erythema in SPT (p≤0.001), and sIgE (p≤0.003) to most milk allergens were significantly decreased following desensitization. We successfully desensitized 16 of 18 children with IgE-mediated CMA by individualized desensitization protocol. Individualizing the OIT protocol would be helpful to save time and perhaps to relieve the allergic symptoms after ingesting cow's milk intake.

A case of oral desensitization for hypersensitivity to exogenous progesterone

Hypersensitivity reaction to progesterone is a rare pathologic condition which consists of autoimmune response to endogenous progesterone, known as autoimmune progesterone dermatitis, and hypersensitivity reaction to exogenous progestogen. We report the case of a 31-year-old woman with a history of whole body urticaria during exogenous progesterone supplementation for in vitro fertilization (IVF). She was admitted to the hospital for the diagnosis and management of progestogen hypersensitivity. An intradermal test with progesterone revealed positivity to 5 mg/mL of progesterone. For her next IVF, progesterone desensitization was performed in a method combining oral and intramuscular progesterone administration. After successfully achieving a target dose of 100 mg per day, the route of progesterone administration was converted to intravaginal tablet (90 mg twice a day) without any hypersensitivity reactions.

Successful desensitization of a patient with albumin hypersensitivity

There have been few cases of albumin hypersensitivity reported, and there is limited information on this condition. When a patient is anaphylactic to a certain drug and no alternative drug is available to treat the underlying condition, desensitization is a reasonable option and can be performed successfully to treat the patient. A standard 12-step, 3-solution rapid desensitization protocol allows the safe readministration of a medication after certain types of immediate hypersensitivity. However, we demonstrated that a new 10-step, 1-solution desensitization protocol using antihistamine and leukotriene receptor antagonist as premedications, which was effective and safe in a patient with hypersensitivity. We report a 13-year-old boy with Gorham-stout syndrome who was presented with newly acquired albumin anaphylaxis and successfully treated with the 10-step rapid drug desensitization protocol.