Mast cells are key effector cells in allergic and inflammatory diseases. However, their primary role is most likely in host defence against parasitic and bacterial infections. Mast cells are a particularly rich source of serine proteases. These proteases belong to the chymase or the tryptase family, which are encoded from the mast cell chymase and the multigene tryptase loci, respectively. To better understand the biological functions and the molecular evolution of these enzymes we have studied the organisation of these two loci in species ranging from fish to human. We show that the mast cell chymase locus has evolved from a single founder gene to a complex locus during the past 200 Myr of mammalian evolution. Forty-five fish candidate genes for hematopoietic serine proteases were also identified. However, in phylogenetic analyses none of them grouped with individual branches holding mammalian mast cell chymase locus genes, indicating an independent parallel evolution in fish. Studies of the evolution of the multigene tryptase locus showed that this locus has been highly conserved between marsupials and eutherians. However, no genes belonging to the individual subfamilies identified in eutherians could be identified in fish, amphibians or in birds, which also here indicates parallel evolution. To study the evolution of specific cleavage specificities associated with these proteases, the extended cleavage specificity of opossum α-chymase was determined and found to be nearly identical to human mast cell chymase and the major mouse mast cell chymase mMCP-4. This indicates a strong pressure to maintain this specificity during mammalian evolution. Basophils are rare blood cells with functions similar to mast cells that when mature almost completely lack mRNA. To study the proteome and to primarily characterize the granule protein content of basophils, an in vitro purification protocol was developed to obtain transcriptionally active umbilical cord blood-derived basophil precursors.

Les IgIV, une préparation thérapeutique d'IgG normales, sont utilisées dans le traitement de diverses maladies auto-immunes et inflammatoires. Les mécanismes par lesquels les IgIV exercent une activité anti-inflammatoire ne sont pas complètement compris. Elles interagissent avec de nombreux composants du système immunitaire et modulent leurs fonctions. Des études récentes ont rapporté que l'hème oxygénase-1 (HO-1) joue un rôle important dans la régulation de la réponse inflammatoire dans un certain nombre de pathologies. Plusieurs agents thérapeutiques exercent des effets anti-inflammatoires grâce à l'induction de l'HO-1. Etant donné le rôle commun anti-inflammatoire de l'HO-1 et des IgIV, j'ai étudié l'implication de l'HO-1 dans les mécanismes d'action des IgIV. J'ai montré que les effets des IgIV ne sont pas associés à l'induction de l'HO-1, que ce soit dans des cellules de l'immunité innée comme les monocytes, cellules dendritiques ou macrophages, ou dans les reins et foie de souris avec une encéphalomyélite auto-immune expérimentale traitées par les IgIV. Des données récentes dans des modèles expérimentaux suggèrent que les IgIV induisent la sécrétion d’IL-4 des basophiles en augmentant l’IL-33 des cellules innées SIGN-R1+. J’ai rapporté que les IgIV induisent directement l’activation de basophiles pré-stimulés avec l’IL-3 alors que contrairement au modèle murin, l’IL-33 n’est pas indispensable. L’activation des basophiles par les IgIV est associée à l’expression augmentée de CD69 et la sécrétion d’IL-4, d’IL-6 et d’IL-8. Ces fonctions sont médiées par les fragments F(ab’)2 qui se lient à des IgE membranaires et activent la voie Syk. / Intravenous immunoglobulin (IVIG), a therapeutic normal immunoglobulin G preparation, is used in the therapy of various autoimmune and inflammatory conditions. The mechanisms by which IVIG exerts anti-inflammatory effects are not completely understood. It interacts with numerous components of the immune system including dendritic cells, macrophages, T and B cells and modulates their functions. Recent studies have reported that heme oxygenase-1 (HO-1) pathway plays an important role in the regulation of inflammatory response in several pathologies. Several therapeutic agents exert anti-inflammatory effects via induction of HO-1. Therefore, in view of common anti-inflammatory role exerted by both HO-1 and IVIG, I investigated if mechanisms of IVIG implicate HO-1. I show that anti-inflammatory effects of IVIG were not associated with an induction of HO-1 either in innate cells such as monocytes, dendritic cells and macrophages or in the kidneys or liver of experimental autoimmune encephalomyelitis. Recent data in experimental models suggest that IVIG induces IL-4 in basophils by enhancing IL-33 in SIGN-R1+ innate cells. I reported that IVIG directly induces activation of IL-3-primed basophils while unlike mice IL-33 was dispensable. The activation of basophils by IVIG was associated with enhanced expression of CD69 and secretion of IL-4, IL-6 and IL-8. These functions of IVIG are mediated via F(ab’)2 fragments that bind to basophil surface IgE and activate Syk pathway.

<p>Nitric oxide (NO) is expressed in inflammatory tissues. However, NO effects are controversial in inflammation; NO is described as acting in a dose dependent manner and possess both pro-inflammatory and anti-inflammatory properties. </p><p>The present thesis explored the role of NO in relation to white blood cell (WBC) and protein system activation by foreign surfaces in simulated extracorporeal circulation (SECC) using human whole blood from volunteer donors. Three doses of NO, 40 ppm, 80 ppm and 500 ppm, were administered and an array of markers of WBC and protein activation were studied. Neutrophil degranulation was detected with myeloperoxidase (MPO), human neutrophil lipocalin (HNL) and lactoferrin (LF); eosinophil degranulation with eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO); and basophil degranulation with histamine. Furthermore, whole blood and WBC capacity to produce reactive oxygen species (ROS) were studied and cytokine release was measured with IL-1 and IL-10. Complement activation was measured with C3a and C5b-9 complex and contact system activation with FXIIa-C1INH, FXIIa-AT, FXIa-C1INH and FXIa-AT.</p><p>NO increased neutrophil degranulation at all dose levels and 80 ppm NO increased basophil degranulation; whereas, NO exerted no effect on eosinophil degranulation, WBC subset counts, cytokine release or capacity to produce ROS. In addition, while increasing both specific and azurophil degranulation with 40 ppm, 80 ppm and 500 ppm, NO reversed the classical degranulation hierarchy with 500 ppm and azurophil degranulation became predominant. Furthermore, NO effect was greater with 500 ppm than with 80 ppm, indicating a dose response effect. The lack of iNOS mRNA expression in WBC and lack of L-NAME effect on degranulation and nitrite/nitrate production, together with absent increase in nitrite/nitrate in controls, excluded autocrine or paracrine regulation of degranulation. FXIIa-AT and FXIa-AT complexes increased and became predominant during early recirculation, whereas FXIIa-C1INH and FXIa-C1INH complexes were predominant at baseline but remained unaltered, suggesting contact system inhibition predominantly via AT. C3a and C5b-C9 increased. NO had no effect on either contact or complement system activation; however, 500 ppm NO shortened active clotting time.</p><p>In conclusion, the present data suggest that NO has a direct effect on neutrophil and basophil degranulation. Recognition of NO as an enhancer of degranulation may give access to new therapeutic tools for local and systemic inflammatory therapies; whereas, the identification of increased AT mediated inhibition of FXIIa and unchanged C1INH complexes presents new possibilities for therapeutic intervention in conditions such as hereditary angioedema and heart surgery.</p>

Nitric oxide (NO) is expressed in inflammatory tissues. However, NO effects are controversial in inflammation; NO is described as acting in a dose dependent manner and possess both pro-inflammatory and anti-inflammatory properties. The present thesis explored the role of NO in relation to white blood cell (WBC) and protein system activation by foreign surfaces in simulated extracorporeal circulation (SECC) using human whole blood from volunteer donors. Three doses of NO, 40 ppm, 80 ppm and 500 ppm, were administered and an array of markers of WBC and protein activation were studied. Neutrophil degranulation was detected with myeloperoxidase (MPO), human neutrophil lipocalin (HNL) and lactoferrin (LF); eosinophil degranulation with eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO); and basophil degranulation with histamine. Furthermore, whole blood and WBC capacity to produce reactive oxygen species (ROS) were studied and cytokine release was measured with IL-1 and IL-10. Complement activation was measured with C3a and C5b-9 complex and contact system activation with FXIIa-C1INH, FXIIa-AT, FXIa-C1INH and FXIa-AT. NO increased neutrophil degranulation at all dose levels and 80 ppm NO increased basophil degranulation; whereas, NO exerted no effect on eosinophil degranulation, WBC subset counts, cytokine release or capacity to produce ROS. In addition, while increasing both specific and azurophil degranulation with 40 ppm, 80 ppm and 500 ppm, NO reversed the classical degranulation hierarchy with 500 ppm and azurophil degranulation became predominant. Furthermore, NO effect was greater with 500 ppm than with 80 ppm, indicating a dose response effect. The lack of iNOS mRNA expression in WBC and lack of L-NAME effect on degranulation and nitrite/nitrate production, together with absent increase in nitrite/nitrate in controls, excluded autocrine or paracrine regulation of degranulation. FXIIa-AT and FXIa-AT complexes increased and became predominant during early recirculation, whereas FXIIa-C1INH and FXIa-C1INH complexes were predominant at baseline but remained unaltered, suggesting contact system inhibition predominantly via AT. C3a and C5b-C9 increased. NO had no effect on either contact or complement system activation; however, 500 ppm NO shortened active clotting time. In conclusion, the present data suggest that NO has a direct effect on neutrophil and basophil degranulation. Recognition of NO as an enhancer of degranulation may give access to new therapeutic tools for local and systemic inflammatory therapies; whereas, the identification of increased AT mediated inhibition of FXIIa and unchanged C1INH complexes presents new possibilities for therapeutic intervention in conditions such as hereditary angioedema and heart surgery.

INTRODUÇÃO: O câncer constitui-se na principal causa de mortalidade entre indivíduos de 45 a 84 anos, configurando-se em um dos principais problemas de saúde pública dos países em desenvolvimento. As reações de hipersensibilidade aos quimioterápicos têm aumentado, impedindo muitas vezes a utilização de terapias de primeira linha no tratamento de neoplasias primárias ou recidivantes. O procedimento de dessensibilização é uma abordagem alternativa, por meio do qual o paciente passa a tolerar a medicação que antes desencadeava reações potencialmente letais. Quimioterápicos do grupo das platinas são exemplos de drogas passíveis de readministração por meio do processo de dessensibilização, no entanto faltam biomarcadores preditivos de reações durante o procedimento. OBJETIVOS: O objetivo principal do estudo foi avaliar o papel do teste de ativação de basófilos (BAT) como biomarcador para reações de hipersensibilidade ocorridas durante a dessensibilização em pacientes alérgicas às platinas. Como objetivo secundário, avaliou-se a prevalência e o impacto da mutação dos genes BRCA 1 e 2 em pacientes com hipersensibilidade imediata à carboplatina submetidas à dessensibilização. MÉTODOS: Padronizou-se o BAT, com análise da expressão de CD63 e CD203c na superfície de basófilos de pacientes com hipersensibilidade imediata às platinas submetidas à dessensibilização. Foram realizados BATs em 15 pacientes portadoras de neoplasias malignas submetidas a 27 dessensibilizações devido à anafilaxia a quimioterápico do grupo das platinas e em 12 indivíduos de dois grupos controle (Grupo 1: seis pacientes tolerantes às platinas e Grupo 2: seis voluntários sadios que nunca foram expostos às platinas). Os resultados dos BATs foram comparados entre os três grupos. Correlacionou-se o BAT com a ocorrência ou não de reação durante a dessensibilização e com os níveis de triptase sérica. Para análise da prevalência e impacto da mutação dos genes BRCA 1 e 2 nas dessensibilizações, realizou-se análise retrospectiva de prontuários de 138 portadoras de neoplasias malignas ginecológicas submetidas à dessensibilização à carboplatina. RESULTADOS: O BAT foi positivo em 11 das 15 pacientes alérgicas (n= 11; 73,3%), com aumento de expressão de CD203c e CD63 em 11 (73,3%) e 6 (40%) pacientes, respectivamente. Todos os participantes dos grupos controles apresentaram testes negativos. Maior expressão de CD63 foi observada em pacientes com reações iniciais mais graves. O BAT foi positivo em 92,3% das reações ocorridas durante as dessensibilizações (n=12/13), sendo positivo em todas as reações que apresentaram aumento concomitante de triptase sérica (n=5). Com relação à mutação dos genes BRCA 1 e 2, sua prevalência foi de 34% nas pacientes com hipersensibilidade às platinas (n=47/138), sendo que 51% das portadoras reagiram durante a dessensibilização. CONCLUSÕES: O BAT positivo, com aumento da expressão de CD63 e/ou CD203c na superfície do basófilo, identificou pacientes alérgicos às platinas com especificidade de 100% e sensibilidade de 73,3%. O BAT e a mutação dos genes BRCA 1 e 2 identificaram pacientes mais propensos a reagir durante o procedimento de dessensibilização. A utilização de biomarcadores preditores de reações durante a dessensibilização aos quimioterápicos do grupo das platinas pode aumentar a segurança do procedimento e auxiliar na manutenção do esquema quimioterápico de primeira linha do paciente / INTRODUCTION: Cancer is the leading cause of death in the age group of 45 to 84 years, and one of the main public health issues in developing nations. Hypersensitivity reactions to chemotherapeutic agents have been increasing, sometimes hindering the use of first-line therapies in the treatment of primary or relapsed tumors. Rapid drug desensitization (RDD) is an alternative approach, through which a patient becomes tolerant to the medication that once triggered a potentially lethal hypersensitivity reaction. Platinum-based compounds are examples of drugs that can be readministered through the desensitization procedure, but currently there are no known biomarkers that could help predict reactions during RDD. OBJECTIVES: The main goal of our study was to assess the basophil activation test (BAT) as a biomarker of breakthrough reactions occurred during RDD in patients allergic to platinum-based agents. As a secondary goal, we evaluated the prevalence and impact of the BRCA 1/2 mutation in carboplatin-allergic patients undergoing RDD. METHODS: We standardized the BAT by evaluating CD63 and CD203c expressions on the basophils of patients with immediate hypersensitivity reactions to platinum-based agents undergoing RDD. We analyzed BATs of 15 patients with malignant neoplasms who had undergone 27 RDD procedures due to anaphylaxis to platinum-based agents, and of 12 control subjects (Group 1: six patients tolerant to platinum-based agents, and Group 2: six healthy volunteers who had never been exposed to platinum-based agents). BAT results were compared among the three groups. We correlated BAT results with the occurrence of breakthrough reactions during RDD and with serum tryptase levels. To conduct the analysis of the BRCA 1/2 mutation prevalence and its impact on RDD, a retrospective review of 138 medical records of patients with gynecological malignancies who underwent RDD to carboplatin was performed. RESULTS: BAT was positive in 11/15 allergic patients (73.3%), with increased expression of CD203c and CD63 in 11 (73.3%) and 6 (40%) patients, respectively. All control subjects presented negative BATs. A higher CD63 expression was observed in patients with severe initial reactions. BAT was positive in 92.3% of the breakthrough reactions occurred during RDD (n=12/13), and in all reactions with concomitant increased tryptase levels (n=5). Regarding the BRCA1/2 mutation, its prevalence was 34% in patients allergic to platinum-based agents (n=47/138), and 51% of the mutation carriers had breakthrough reactions during RDD. CONCLUSIONS: A positive BAT, with an increased expression of CD63 and/or CD203c, identified patients allergic to platinum-based agents with a specificity of 100% and a sensitivity of 73.3%. The BAT and the BRCA 1/2 mutation helped identify patients at risk of breakthrough reactions during RDD. The use of predictive biomarkers of breakthrough reactions during RDD to platinum-based agents might enhance RDD safety and help maintain a patient`s first-line treatment

INTRODUÇÃO: O câncer constitui-se na principal causa de mortalidade entre indivíduos de 45 a 84 anos, configurando-se em um dos principais problemas de saúde pública dos países em desenvolvimento. As reações de hipersensibilidade aos quimioterápicos têm aumentado, impedindo muitas vezes a utilização de terapias de primeira linha no tratamento de neoplasias primárias ou recidivantes. O procedimento de dessensibilização é uma abordagem alternativa, por meio do qual o paciente passa a tolerar a medicação que antes desencadeava reações potencialmente letais. Quimioterápicos do grupo das platinas são exemplos de drogas passíveis de readministração por meio do processo de dessensibilização, no entanto faltam biomarcadores preditivos de reações durante o procedimento. OBJETIVOS: O objetivo principal do estudo foi avaliar o papel do teste de ativação de basófilos (BAT) como biomarcador para reações de hipersensibilidade ocorridas durante a dessensibilização em pacientes alérgicas às platinas. Como objetivo secundário, avaliou-se a prevalência e o impacto da mutação dos genes BRCA 1 e 2 em pacientes com hipersensibilidade imediata à carboplatina submetidas à dessensibilização. MÉTODOS: Padronizou-se o BAT, com análise da expressão de CD63 e CD203c na superfície de basófilos de pacientes com hipersensibilidade imediata às platinas submetidas à dessensibilização. Foram realizados BATs em 15 pacientes portadoras de neoplasias malignas submetidas a 27 dessensibilizações devido à anafilaxia a quimioterápico do grupo das platinas e em 12 indivíduos de dois grupos controle (Grupo 1: seis pacientes tolerantes às platinas e Grupo 2: seis voluntários sadios que nunca foram expostos às platinas). Os resultados dos BATs foram comparados entre os três grupos. Correlacionou-se o BAT com a ocorrência ou não de reação durante a dessensibilização e com os níveis de triptase sérica. Para análise da prevalência e impacto da mutação dos genes BRCA 1 e 2 nas dessensibilizações, realizou-se análise retrospectiva de prontuários de 138 portadoras de neoplasias malignas ginecológicas submetidas à dessensibilização à carboplatina. RESULTADOS: O BAT foi positivo em 11 das 15 pacientes alérgicas (n= 11; 73,3%), com aumento de expressão de CD203c e CD63 em 11 (73,3%) e 6 (40%) pacientes, respectivamente. Todos os participantes dos grupos controles apresentaram testes negativos. Maior expressão de CD63 foi observada em pacientes com reações iniciais mais graves. O BAT foi positivo em 92,3% das reações ocorridas durante as dessensibilizações (n=12/13), sendo positivo em todas as reações que apresentaram aumento concomitante de triptase sérica (n=5). Com relação à mutação dos genes BRCA 1 e 2, sua prevalência foi de 34% nas pacientes com hipersensibilidade às platinas (n=47/138), sendo que 51% das portadoras reagiram durante a dessensibilização. CONCLUSÕES: O BAT positivo, com aumento da expressão de CD63 e/ou CD203c na superfície do basófilo, identificou pacientes alérgicos às platinas com especificidade de 100% e sensibilidade de 73,3%. O BAT e a mutação dos genes BRCA 1 e 2 identificaram pacientes mais propensos a reagir durante o procedimento de dessensibilização. A utilização de biomarcadores preditores de reações durante a dessensibilização aos quimioterápicos do grupo das platinas pode aumentar a segurança do procedimento e auxiliar na manutenção do esquema quimioterápico de primeira linha do paciente / INTRODUCTION: Cancer is the leading cause of death in the age group of 45 to 84 years, and one of the main public health issues in developing nations. Hypersensitivity reactions to chemotherapeutic agents have been increasing, sometimes hindering the use of first-line therapies in the treatment of primary or relapsed tumors. Rapid drug desensitization (RDD) is an alternative approach, through which a patient becomes tolerant to the medication that once triggered a potentially lethal hypersensitivity reaction. Platinum-based compounds are examples of drugs that can be readministered through the desensitization procedure, but currently there are no known biomarkers that could help predict reactions during RDD. OBJECTIVES: The main goal of our study was to assess the basophil activation test (BAT) as a biomarker of breakthrough reactions occurred during RDD in patients allergic to platinum-based agents. As a secondary goal, we evaluated the prevalence and impact of the BRCA 1/2 mutation in carboplatin-allergic patients undergoing RDD. METHODS: We standardized the BAT by evaluating CD63 and CD203c expressions on the basophils of patients with immediate hypersensitivity reactions to platinum-based agents undergoing RDD. We analyzed BATs of 15 patients with malignant neoplasms who had undergone 27 RDD procedures due to anaphylaxis to platinum-based agents, and of 12 control subjects (Group 1: six patients tolerant to platinum-based agents, and Group 2: six healthy volunteers who had never been exposed to platinum-based agents). BAT results were compared among the three groups. We correlated BAT results with the occurrence of breakthrough reactions during RDD and with serum tryptase levels. To conduct the analysis of the BRCA 1/2 mutation prevalence and its impact on RDD, a retrospective review of 138 medical records of patients with gynecological malignancies who underwent RDD to carboplatin was performed. RESULTS: BAT was positive in 11/15 allergic patients (73.3%), with increased expression of CD203c and CD63 in 11 (73.3%) and 6 (40%) patients, respectively. All control subjects presented negative BATs. A higher CD63 expression was observed in patients with severe initial reactions. BAT was positive in 92.3% of the breakthrough reactions occurred during RDD (n=12/13), and in all reactions with concomitant increased tryptase levels (n=5). Regarding the BRCA1/2 mutation, its prevalence was 34% in patients allergic to platinum-based agents (n=47/138), and 51% of the mutation carriers had breakthrough reactions during RDD. CONCLUSIONS: A positive BAT, with an increased expression of CD63 and/or CD203c, identified patients allergic to platinum-based agents with a specificity of 100% and a sensitivity of 73.3%. The BAT and the BRCA 1/2 mutation helped identify patients at risk of breakthrough reactions during RDD. The use of predictive biomarkers of breakthrough reactions during RDD to platinum-based agents might enhance RDD safety and help maintain a patient`s first-line treatment

Introdução: Atualmente, o diagnóstico das reações de hipersensibilidade a anti-inflamatórios não esteroidais (AINEs) baseia-se na história relatada pelo paciente e, em determinados casos, é realizado o Teste de Provocação. Todavia, este teste pode expor os pacientes a riscos graves, inclusive anafilaxia. Em busca de ferramenta mais segura, tem-se estudado o Teste de Ativação de Basófilos (BAT). Trata-se de um teste in vitro, no qual é possível testar diversos estímulos em uma única amostra de sangue, avaliando a ativação dos basófilos (indicativo de reação de hipersensibilidade), através do aumento da expressão de moléculas na superfície desses leucócitos, como o CD63. Objetivo: Padronizar e validar o BAT para ácido acetilsalicílico (AAS), diclofenaco, dipirona e paracetamol em pacientes com hipersensibilidade a AINEs. Metodologia: Participaram 20 (testados com os quatro AINEs) + 33 (testados somente com AAS) pacientes atendidos no Serviço de Imunologia Clínica e Alergia do HCFMUSP, que apresentaram manifestações cutâneas em até 24 horas após exposição a um ou múltiplos AINEs, bem como 13 (quatro AINEs) + 26 (AAS) controles. A técnica consistiu em incubar sangue total com os AINEs já mencionados e, depois, marcar as amostras com anticorpos monoclonais (CD45, anti-IgE e CD63) para posterior leitura por citometria de fluxo. Os resultados obtidos foram comparados com as histórias clínicas e os testes de provocação oral, quando realizados. Resultados: Utilizando os critérios de positividade do BAT empregados na literatura (isto é, porcentagem de CD45+IgE+highCD63+ e índice de estimulação), a sensibilidade e a especificidade variaram de acordo com o AINE: para ácido acetilsalicílico foram 75,0% e 16,7%, respectivamente, diclofenaco, 100% e 0%, dipirona, 23,5% e 66,7%, paracetamol, 40,0% e 42,9%. Após a realização de curvas dose-resposta e tempo-resposta somente com AAS, foi encontrado novo critério de positividade: média de intensidade de fluorescência (MFI) menor do que 6575 representava BAT positivo; com isso, os valores de sensibilidade e especificidade foram: 84,4% e 34,6%, respectivamente. O BAT foi mais sensível em pacientes cuja última reação ocorreu há menos de um ano da data de execução do BAT (93,7%). Conclusão: Devido aos baixos valores de sensibilidade e/ou especificidade, não foi possível padronizar e, por conseguinte, validar o BAT para ácido acetilsalicílico, diclofenaco, dipirona e paracetamol. / Introduction: Currently, the diagnosis of nonsteroidal antiinflammatory drugs (NSAIDs) hypersensivitity is based on patients´ clinical history and drug provocation tests, which are done in selected cases. Nevertheless, this test may expose patients to severe risks, including anaphylaxis. Looking for a safer tool, Basophil Activation Test (BAT) for allergy diagnosis has been studied in the last years. It is an in vitro method where a wide variety of stimuli can be tested, incubating them with the patient\'s blood sample, and observing basophil activation (indication of hypersensitivity) through upregulation of CD63 (or other basophil activation markers) on this leucocyte\'s membrane. Objective: To standardize and validate BAT stimulated with acetylsalicylic acid (ASA), diclophenac, dipyrone and paracetamol in NSAID hypersensitive patients. Methods: Patients which reported immediate reactions (less than 24 hours) after exposure to one or multiple NSAIDs, with cutaneous symptoms were enrolled from Clinical Immunology and Allergy outpatient clinic from HC-FMUSP. BAT with the four NSAIDs was tested on 20 patients and 13 controls and BAT with ASA only, on 33 patients and 26 controls. BAT consisted of incubating whole blood with NSAIDs, then triple-labeled with monoclonal antibodies (CD45, anti-IgE, CD63) for analysis by flow cytometry. BAT results were compared to clinical history and oral provocation tests, when available. Results: According to literature\'s positivity criteria (percentage of CD45+IgE+highCD63+ and stimulation index), sensitivity and specificity varied according to the NSAID tested: for ASA was 75.0% and 16.7% respectively, diclophenac, 100.0% and 0.0%, dipyrone, 23.5% and 66.7%, paracetamol, 40.0% and 42.9%. A new positivity criterion was possible to be defined after further dose-response and time-response curves only for ASA: Mean Fluorescence Intensity lower than 6575 (positive BAT). Accordingly, new sensitivity and specificity for BAT in ASA hypersensitivity were 84,4% and 34,6%. Patients that presented the last reaction in the last year were more likely to present a positive BAT (93.7%). Conclusion: Due to low values for sensitivity and/or specificity, it was not possible to standardize and validate BAT for ASA, diclophenac, dipyrone and paracetamol.

Introdução: Atualmente, o diagnóstico das reações de hipersensibilidade a anti-inflamatórios não esteroidais (AINEs) baseia-se na história relatada pelo paciente e, em determinados casos, é realizado o Teste de Provocação. Todavia, este teste pode expor os pacientes a riscos graves, inclusive anafilaxia. Em busca de ferramenta mais segura, tem-se estudado o Teste de Ativação de Basófilos (BAT). Trata-se de um teste in vitro, no qual é possível testar diversos estímulos em uma única amostra de sangue, avaliando a ativação dos basófilos (indicativo de reação de hipersensibilidade), através do aumento da expressão de moléculas na superfície desses leucócitos, como o CD63. Objetivo: Padronizar e validar o BAT para ácido acetilsalicílico (AAS), diclofenaco, dipirona e paracetamol em pacientes com hipersensibilidade a AINEs. Metodologia: Participaram 20 (testados com os quatro AINEs) + 33 (testados somente com AAS) pacientes atendidos no Serviço de Imunologia Clínica e Alergia do HCFMUSP, que apresentaram manifestações cutâneas em até 24 horas após exposição a um ou múltiplos AINEs, bem como 13 (quatro AINEs) + 26 (AAS) controles. A técnica consistiu em incubar sangue total com os AINEs já mencionados e, depois, marcar as amostras com anticorpos monoclonais (CD45, anti-IgE e CD63) para posterior leitura por citometria de fluxo. Os resultados obtidos foram comparados com as histórias clínicas e os testes de provocação oral, quando realizados. Resultados: Utilizando os critérios de positividade do BAT empregados na literatura (isto é, porcentagem de CD45+IgE+highCD63+ e índice de estimulação), a sensibilidade e a especificidade variaram de acordo com o AINE: para ácido acetilsalicílico foram 75,0% e 16,7%, respectivamente, diclofenaco, 100% e 0%, dipirona, 23,5% e 66,7%, paracetamol, 40,0% e 42,9%. Após a realização de curvas dose-resposta e tempo-resposta somente com AAS, foi encontrado novo critério de positividade: média de intensidade de fluorescência (MFI) menor do que 6575 representava BAT positivo; com isso, os valores de sensibilidade e especificidade foram: 84,4% e 34,6%, respectivamente. O BAT foi mais sensível em pacientes cuja última reação ocorreu há menos de um ano da data de execução do BAT (93,7%). Conclusão: Devido aos baixos valores de sensibilidade e/ou especificidade, não foi possível padronizar e, por conseguinte, validar o BAT para ácido acetilsalicílico, diclofenaco, dipirona e paracetamol. / Introduction: Currently, the diagnosis of nonsteroidal antiinflammatory drugs (NSAIDs) hypersensivitity is based on patients´ clinical history and drug provocation tests, which are done in selected cases. Nevertheless, this test may expose patients to severe risks, including anaphylaxis. Looking for a safer tool, Basophil Activation Test (BAT) for allergy diagnosis has been studied in the last years. It is an in vitro method where a wide variety of stimuli can be tested, incubating them with the patient\'s blood sample, and observing basophil activation (indication of hypersensitivity) through upregulation of CD63 (or other basophil activation markers) on this leucocyte\'s membrane. Objective: To standardize and validate BAT stimulated with acetylsalicylic acid (ASA), diclophenac, dipyrone and paracetamol in NSAID hypersensitive patients. Methods: Patients which reported immediate reactions (less than 24 hours) after exposure to one or multiple NSAIDs, with cutaneous symptoms were enrolled from Clinical Immunology and Allergy outpatient clinic from HC-FMUSP. BAT with the four NSAIDs was tested on 20 patients and 13 controls and BAT with ASA only, on 33 patients and 26 controls. BAT consisted of incubating whole blood with NSAIDs, then triple-labeled with monoclonal antibodies (CD45, anti-IgE, CD63) for analysis by flow cytometry. BAT results were compared to clinical history and oral provocation tests, when available. Results: According to literature\'s positivity criteria (percentage of CD45+IgE+highCD63+ and stimulation index), sensitivity and specificity varied according to the NSAID tested: for ASA was 75.0% and 16.7% respectively, diclophenac, 100.0% and 0.0%, dipyrone, 23.5% and 66.7%, paracetamol, 40.0% and 42.9%. A new positivity criterion was possible to be defined after further dose-response and time-response curves only for ASA: Mean Fluorescence Intensity lower than 6575 (positive BAT). Accordingly, new sensitivity and specificity for BAT in ASA hypersensitivity were 84,4% and 34,6%. Patients that presented the last reaction in the last year were more likely to present a positive BAT (93.7%). Conclusion: Due to low values for sensitivity and/or specificity, it was not possible to standardize and validate BAT for ASA, diclophenac, dipyrone and paracetamol.