Asthma is an inflammatory condition characterized by the involvement of several mediators, including reactive oxygen species. The aim of the present study was to investigate the superoxide release and cellular glutathione peroxidase (cGPx) activity in peripheral blood granulocytes and monocytes from children and adolescents with atopic asthma. Forty-four patients were selected and classified as having intermittent or persistent asthma (mild, moderate or severe). The spontaneous or phorbol myristate acetate (PMA, 30 nM)-induced superoxide release by granulocytes and monocytes was determined at 0, 5, 15, and 25 min. cGPx activity was assayed spectrophotometrically. The spontaneous superoxide release by granulocytes from patients with mild (N = 15), moderate (N = 12) or severe (N = 6) asthma was higher at 25 min compared to healthy individuals (N = 28, P < 0.05, Duncan test). The PMA-induced superoxide release by granulocytes from patients with moderate (N = 12) or severe (N = 6) asthma was higher at 15 and 25 min compared to healthy individuals (N = 28, P < 0.05 in both times of incubation, Duncan test). The spontaneous or PMA-induced superoxide release by monocytes from asthmatic patients was similar to healthy individuals (P > 0.05 in all times of incubation, Duncan test). cGPx activity of granulocytes and monocytes from patients with persistent asthma (N = 20) was also similar to healthy individuals (N = 10, P > 0.05, Kruskal-Wallis test). We conclude that, under specific circumstances, granulocytes from children with persistent asthma present a higher respiratory burst activity compared to healthy individuals. These findings indicate a risk of oxidative stress, phagocyte auto-oxidation, and the subsequent release of intracellular toxic oxidants and enzymes, leading to additional inflammation and lung damage in asthmatic children.

Chronic granulomatous disease (CGD) is an inherited disorder of the innate immune system characterized by a defective oxidative burst of phagocytes and subsequent impairment of their microbicidal activity. Mutations in one of the NADPH-oxidase components affect gene expression or function of this system, leading to the phenotype of CGD. Defects in gp91-phox lead to X-linked CGD, responsible for approximately 70% of CGD cases. Investigation of the highly heterogeneous genotype of CGD patients includes mutation analysis, Northern blot or Western blot assays according to the particular case. The aim of the present study was to use reverse transcription (RT)-PCR for the analysis of molecular defects responsible for X-linked CGD in eight Brazilian patients and to assess its potential for broader application to molecular screening in CGD. Total RNA was prepared from Epstein B virus-transformed B-lymphocytes and reverse transcribed using random hexamers. The resulting cDNA was PCR-amplified by specific and overlapping pairs of primers designed to amplify three regions of the gp91-phox gene: exons 1-5, 3-9, and 7-13. This strategy detected defective gp91-phox expression in seven patients. The RT-PCR results matched clinical history, biochemical data (nitroblue tetrazolium or superoxide release assay) and available mutation analysis in four cases. In three additional cases, RT-PCR results matched clinical history and biochemical data. In another case, RT-PCR was normal despite a clinical history compatible with CGD and defective respiratory burst. We conclude that this new application of RT-PCR analysis - a simple, economical and rapid method - was appropriate for screening molecular defects in 7 of 8 X-linked CGD patients.

OBJETIVO: Relatar dois casos de irmãos com doença granulomatosa crônica. A doença granulomatosa crônica é uma imunodeficiência primária caracterizada por atividade microbicida deficiente. Mutações no gene que codifica a proteína p47-phox (NCF-1) estão presentes em 30% dos casos de doença granulomatosa crônica. Essa forma da doença é de herança autossômica recessiva e resulta em fenótipo de evolução mais benigno e início tardio em relação à forma ligada ao X, que corresponde a 56% dos casos. DESCRIÇÃO: Caso 1 - paciente feminina, iniciou infecções de repetição aos 10 anos, com impetigo, seguido de pneumonia grave 6 meses após. A gravidade da infecção pulmonar associada a abscesso hepático e sua refratariedade ao tratamento demandaram investigação laboratorial para imunodeficiência, com teste do nitroblue tetrazolium e dosagem de ânion superóxido compatíveis com doença granulomatosa crônica. A avaliação dos familiares confirmou o mesmo diagnóstico em seu irmão (Caso 2), que também iniciou infecções de repetição com impetigo aos 10 anos e pneumonia 6 meses após, porém tratada com sucesso ambulatorialmente. A análise de polimorfismo conformacional de cadeia simples revelou alteração da mobilidade eletroforética do éxon 2 do gene NCF-1. Identificou-se uma deleção dos nucleotídeos GT no éxon 2 por seqüenciamento do DNA. COMENTÁRIOS: Este estudo mostra a importância da avaliação de familiares, mesmo quando não apresentam história clínica típica de doença granulomatosa crônica. A identificação da mutação e sua correlação com o fenótipo dos pacientes é importante para estabelecer o prognóstico e o aconselhamento genético.

OBJECTIVE: To report the case of two siblings with chronic granulomatous disease. Chronic granulomatous disease is a primary immunodeficiency disorder characterized by abnormal microbicidal activity. Mutations in the p47-phox gene (NCF-1) are present in about 30% of the patients with chronic granulomatous disease; this group presents a better prognosis and later onset of recurrent infections as compared with the X-linked variant, present in about 56% of patients. DESCRIPTION: Case 1 is a female presenting repeat infections since age 10, starting with impetigo followed by severe pneumonia six months later. The severity of the lung infection associated with liver abscess and the patient's resistance to treatment prompted laboratory investigation for immunodeficiency. The results of the nitroblue tetrazolium and superoxide release tests were consistent with a diagnosis of chronic granulomatous disease. The parents and siblings were assessed, revealing the presence of granulomatous disease in a brother (Case 2). He also presented repeat infections with impetigo at age 10, followed by pneumonia six months later, however in a non severe form. Single-strand conformational polymorphism analysis detected abnormal electrophoretic mobility of exon 2 of the NCF-1 gene. Sequence DNA analysis revealed a dinucleotide GT deletion in exon 2. COMMENTS: It is important to evaluate the relatives of chronic granulomatous disease patients, even in the absence of typical clinical signs. Defining the mutation and its correlation with phenotype is important to provide appropriate genetic counseling and clinical prognosis.

OBJETIVO: relatar a ocorrência de uma deficiência funcional de neutrófilos rara, com quadro clínico e laboratorial semelhante ao da doença granulomatosa crônica. MÉTODOS: relato de caso de paciente com deficiência acentuada da glicose-6-fosfato desidrogenase e infecções de repetição. Realizada pesquisa bibliográfica utilizando as bases de dados Medline e Lilacs, abrangendo o período de 1972 a 2000. RESULTADOS: paciente com nível da glicose-6-fosfato desidrogenase extremamente reduzido e quadro de infeções graves com melhora clínica após uso de cotrimoxazol contínuo. Os leucócitos do paciente apresentam defeito no metabolismo oxidativo, similar ao da doença granulomatosa crônica. CONCLUSÕES: o diagnóstico da deficiência da glicose-6-fosfato desidrogenase em neutrófilos deve ser considerado em qualquer paciente com anemia hemolítica não esferocítica congênita no qual o nível da glicose-6-fosfato desidrogenase esteja anormalmente baixo ou apresente infeções de repetição. É diagnóstico diferencial da doença granulomatosa crônica.

OBJECTIVE: To report a case of rare neutrophil functional disorder with clinical and laboratory findings similar to those of chronic granulomatous disease. METHODS: Patient with extremely reduced level of glucose-6-phosphate dehydrogenase and recurrent infections that improved after continuous use of cotrimoxazole. The patient presented leukocytes with defective respiratory burst, similar to what occurs in chronic granulomatous disease. COMMENTS: The diagnosis of glucose-6-phosphate dehydrogenase deficiency in neutrophils should be considered in any patient with hemolytic anemia whose level of G6PD is extremely low or in any patient that presents recurrent infections as differential diagnosis of chronic granulomatous disease.