RESUMO
Abstract INTRODUCTION: The production of the Montenegro antigen for skin test poses difficulties regarding quality control. Here, we propose that certain animal models reproducing a similar immune response to humans may be used in the quality control of Montenegro antigen production. METHODS: Fifteen Cavia porcellus (guinea pigs) were immunized with Leishmania amazonensis or Leishmania braziliensis , and, after 30 days, they were skin tested with standard Montenegro antigen. To validate C. porcellus as an animal model for skin tests, eighteen Mesocricetus auratus (hamsters) were infected with L. amazonensis or L. braziliensis , and, after 45 days, they were skin tested with standard Montenegro antigen. RESULTS: Cavia porcellus immunized with L. amazonensis or L. braziliensis , and hamsters infected with the same species presented induration reactions when skin tested with standard Montenegro antigen 48-72h after the test. CONCLUSIONS: The comparison between immunization methods and immune response from the two animal species validated C. porcellus as a good model for Montenegro skin test, and the model showed strong potential as an in vivo model in the quality control of the production of Montenegro antigen.
Assuntos
Animais , Masculino , Leishmania braziliensis/imunologia , Testes Intradérmicos/normas , Leishmaniose Cutânea/diagnóstico , Modelos Animais , Antígenos de Protozoários/biossíntese , Antígenos de Protozoários/imunologia , Controle de Qualidade , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Leishmania/imunologiaRESUMO
INTRODUCTION: The production of the Montenegro antigen for skin test poses difficulties regarding quality control. Here, we propose that certain animal models reproducing a similar immune response to humans may be used in the quality control of Montenegro antigen production. METHODS: Fifteen Cavia porcellus (guinea pigs) were immunized with Leishmania amazonensis or Leishmania braziliensis , and, after 30 days, they were skin tested with standard Montenegro antigen. To validate C. porcellus as an animal model for skin tests, eighteen Mesocricetus auratus (hamsters) were infected with L. amazonensis or L. braziliensis , and, after 45 days, they were skin tested with standard Montenegro antigen. RESULTS: Cavia porcellus immunized with L. amazonensis or L. braziliensis , and hamsters infected with the same species presented induration reactions when skin tested with standard Montenegro antigen 48-72h after the test. CONCLUSIONS: The comparison between immunization methods and immune response from the two animal species validated C. porcellus as a good model for Montenegro skin test, and the model showed strong potential as an in vivo model in the quality control of the production of Montenegro antigen.
Assuntos
Antígenos de Protozoários/biossíntese , Cobaias/imunologia , Testes Intradérmicos/normas , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/diagnóstico , Modelos Animais , Animais , Leishmania/imunologia , Masculino , Valor Preditivo dos Testes , Controle de Qualidade , Sensibilidade e EspecificidadeRESUMO
Intradermal reactions were performed in 399 individuals by using, simultaneously, the antigen produced by both the Universidade Federal de Minas Gerais and Fundação Instituto Oswaldo Cruz. Each of these antigens was manufactured with promastigotes of Leishmania (L) amazonensis (IFLA/BR/67/PH8). The Fundação Oswaldo Cruz antigen caused a larger number of positive reactions. Discordant reactions occurred in 22% of the individuals.
Assuntos
Antígenos de Protozoários/imunologia , Testes Intradérmicos/normas , Leishmania/imunologia , Leishmaniose Visceral/diagnóstico , Animais , Argentina , Brasil , Doenças Endêmicas , HumanosRESUMO
With the purpose of evaluating the response of sequential applications of Montenegro intradermoreaction (IDRM), we have repeated four times the test in the inhabitants of an endemic area for kala-azar, that resulted negative 3-4 years ago. Firstly, we have repeated three IDRM in those who remained negative, with a 60-day interval among them. In the second stage, we have performed a last reaction in all participants of the study. From the total of 49 individuals with prior negative IDRM, 19 (38.8%) have positivated the test in some of the times, 17 (34.7%) have given up the study and 13 (26.5%) remained with a negative result in all the applications. In the second stage, the repetition of IDRM has shown that from the 14 positive in some of the tests, 8 remained like this and 6 have become negative. Our results confirm the possibility of late hypersensitivity induction in some individuals as a consequence of IDRM application.
Assuntos
Hipersensibilidade Tardia/imunologia , Testes Intradérmicos/normas , Leishmania/imunologia , Leishmaniose Visceral/diagnóstico , Animais , Antígenos de Protozoários/imunologia , Brasil/epidemiologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Reações Falso-Negativas , Humanos , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/imunologiaRESUMO
Para avaliar a resposta a sucessivas aplicaçöes da intradermorreaçäo de Montenegro (IDRM), repetimos quatro vezes o teste em moradores de uma área endêmica de calazar que tiveram o exame negativo há 3-4 anos. Inicialmente, repetimos três IDRM nos que permaneceram negativos, com intervalo de 60 dias entre elas. Na segunda etapa, realizamos uma última reaçäo em todos participantes do estudo. Do total de 49 indivíduos com IDRM prévia negativa, 19 (38,8 por cento) positivaram o teste em alguma das vezes, 17 (34,7 por cento) abandonaram o estudo e 13 (26,5 por cento) permaneceram com resultado negativo em todas as aplicaçöes. Na segunda etapa, a repetiçäo da IDRM mostrou que dos 14 que eram positivos em algum dos testes, 8 assim permaneceram e 6 tornaram-se negativos. Nossos resultados confirmam a possibilidade de induçäo de hipersensibilidade tardia em alguns indivíduos pela aplicaçäo da IDRM
Assuntos
Animais , Humanos , Hipersensibilidade Tardia/imunologia , Testes Intradérmicos/normas , Leishmania/imunologia , Leishmaniose Visceral/diagnóstico , Antígenos de Protozoários/imunologia , Brasil/epidemiologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Reações Falso-Negativas , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/imunologiaRESUMO
We compared in 50 asthmatic children, the cutaneous response by skin prick test to Dermatophagoides farinae with antigens from two different laboratories (Freeman and Hollister). In order to evaluate the importance of the selection, conservation and standardization of the allergic extracts. 27/50 children had a similar response, in those cases (6) where Freeman was doubtful and Hollister positive the allergic etiology was confirmed by RAST and Challenge tests. In 5 cases, Freeman was negative and Hollister doubtful we only confirm allergic etiology in 1. When both were positive all of them were allergic. The antigen Dermatophagoides farinae from Freeman laboratory needs another diagnostic method, when the cutaneous response is doubtful or negative and the clinical feature is highly suggestive. We don't have to forget the importance of the controls positive and negative.