Doença granulomatosa crônica da infância: novos polimorfismos no gene NCF2 / Chronic granulomatous disease of childhood: new polymorphisms in NCF2 gene

Objetivos: Mutações no gene NCF2 resultam na forma autossônica recessiva da doença granulomatosa crônica da infância. Além de mutações conhecidas, descreveu-se em pacientes com doença granulomatosa crônica da infância duas novas substituições no gene NCF2. O objetivo deste estudo foi investigar se estas substituições constituem polimorfismos do gene NCF2. Métodos: Investigamos a freqüência de duas substituições na seqüência do gene NCF2 em 214 doadores sadios. A primeira é uma transição de C T na posição -23 da região 5' reguladora. A segunda é uma transição de A G na posição -21 da região 3' terminal do íntron 10. Extraímos DNA genômico de células do sangue periférico. O DNA foi amplificado por meio de PCR com primers específicos para o gene NCF2, analisado quanto à presença de polimorfismos conformacionais de cadeias simples, digerido com endonucleases específicas e sequenciado. O cálculo das freqüências genotípicas e alélicas seguiu a lei de Hardy e Weinberg. Resultados: Cem indivíduos foram avaliados quanto à presença da transição C T na posição -23 da região 5' reguladora; sendo 67 porcento homozigotos para o alelo c, 32 porcento heterozigotos, e apenas 1 porcento homozigoto para T. Cento e quatorze indivíduos foram analisados quanto à presença da transição A G na posição -21 da região 3' terminal do íntron 10; dos quais 36 porcento foram homozigotos para A, 43 porcento heterozigotos e 21 porcento homozigotos para G. Conclusão: Considerando as freqüências alélicas, concluímos que essas variantes correspondem a polimorfismos do gene NCF2. Suas possíveis implicações na expressão do gene NCF2 constituem objeto de pesquisa atual em nosso laboratório.

The tryptic cleavage product of the mature form of the bovine desmoglein 1 ectodomain is one of the antigen moieties immunoprecipitated by all sera from symptomatic patients affected by a new variant of endemic pemphigus.

Multiple antigens are recognized by sera from patients with pemphigus foliaceus (PF). Several have been identified including keratin 59, desmocollins, envoplakin, periplakin, and desmogleins 1 and 3 (Dsg1 and Dsg3). In addition, an 80 kDa antigen was identified as the N-terminal fragment of Dsg1 using as antigen source an insoluble epidermal cell envelope preparation. However, still unsolved was the identity of the most important antigenic moiety, a 45 kDa tryptic fragment which is recognized by all sera from patients with fogo selvagem, pemphigus foliaceus, by half of pemphigus vulgaris sera and by a new variant of endemic pemphigus in E1 Bagre, Colombia that resembles Senear-Usher syndrome. Here, we report the identification of the 45 kDa conformational epitope of a soluble tryptic cleavage product from viable bovine epidermis. To elucidate the nature of this peptide, viable bovine epidermis was trypsin-digested, and glycosylated peptides were partially purified on a concanavalin A (Con-A) affinity column. This column fraction was then used as an antigen source for further immunoaffinity purification. A PF patient's serum covalently coupled to a Staphylococcus aureus protein A column was incubated with the Con-A eluted products and the immuno-isolated antigen was separated by SDS-PAGE, transferred to a membrane, and visualized with Coomassie blue, silver and amido black stains. The 45 kD band was subjected to amino acid sequence analysis revealing the sequence, EXIKFAAAXREGED, which matched the mature form of the extracellular domain of bovine Dsg1. This study confirms the biological importance of the ectodomain of Dsg1 as well as the relevance of conformational epitopes in various types of pemphigus.

Análisis de laboratorio en los pacientes que presentan infección recurrente y pueden sufrir de inmunodeficiencia / Analysis of laboratory in the patients who has recurrent infection and can suffer of immunodeficiency

The syndrome of recurrent infection constitutes an important cause of morbidity and mortality, both indeveloped and non-developed countries, which implies high social and economic costs for the health services.Practically all individuals with an appropriate immune response have important periods of recurrentinfections, which we can consider as normal. These infectious processes allow that the immune system learnshow to respond against an environment that is plenty of microorganisms with capacity to produce infectionsin an immunocompetent subject. Nevertheless recurrent infections associated with certain characteristicsmight reflect an abnormal increase of the susceptibility of an individual to certain infectious processes. Oncethe study of a patient with recurrent infection syndrome begins, it is fundamental to establish if an underlyinginmunological defect exists, which might explain the development of severe infections. The laboratoryevaluation is an important step in the goal to establish a specific diagnosis of an immunodeficiency disease. Aprecise diagnosis besides to the accelerated development of the immunotherapy, opens the possibility ofprescribing an opportune and rational treatment. An appropriate treatment must have as main goal to avoidthe relapse of infections and the development of sequels and at the same time to improve the quality of life ofthe patient and her or his family. In this article we would show a sequential scheme for the study ofthe immune response in patients that present abnormal recurrent infections. This algorithm will helpthe clinician to establish a soon phenotypic diagnosis and laterly to make a molecular characterizationof the immunodeficiency that has been identified.