Triagem familiar para o gene HBB*S e detecção de novos casos de traço falciforme em Pernambuco / Family screening for HBB*S gene and detection of new cases of sickle cell trait in Northeastern Brazil

OBJETIVO: Estimar o incremento no número adicional de afetados com base na prevalência de síndromes falciformes em familiares de casos-índice. MÉTODOS: Estudo transversal em familiares de amostra aleatória dos casos-índice identificados por programa de triagem neonatal em Pernambuco, no período de 2001 a 2005. O modelo de triagem familiar ampliado incluiu 463 membros familiares de 21 casos-índice. Os familiares foram categorizados como: núcleo reduzido (NR -pai, mãe e irmãos); de primeiro grau (N1 - avós, tios e primos de primeiro grau); de segundo grau (N2 - filhos dos primos de primeiro grau); ampliado (NA - NR+N1+N2) e ampliado de primeiro grau (NA1 -NR+N1). A confirmação da presença de HBB*S e detecção de hemoglobinas anormais foram realizadas por meio da High Performance Liquid Chromathgraphy. A associação entre a presença de HBB*S e variáveis foi testada pelo cálculo da razão de prevalência e respectivos IC 95 por cento e a diferença entre médias verificadas pelo teste t de Student, ao nível de significância de 5 por cento. RESULTADOS: A anemia falciforme era desconhecida por 81 por cento dos familiares; o gene HBB*S esteve presente em 114 familiares. Observou-se que 53,3 por cento da população estudada estava na faixa considerada reprodutiva e 80 por cento das pessoas portadoras do gene HBB*S já tinham gerado filhos. A freqüência foi maior no núcleo NR (69 por cento), mas também elevada no N1 (22,8 por cento). O NA1 resultou na detecção de 69 portadores adicionais (aumento de 172 por cento). CONCLUSÕES: Os resultados indicam que a triagem familiar para identificação de portadores de síndrome falciforme deve ser estendida para os familiares até o primeiro grau.

OBJECTIVE: To estimate the additional number of affected individuals based on the prevalence of sickle-cell syndromes among relatives of index cases. METHODS: Cross-sectional study of relatives of a random sample of index cases identified through a neonatal screening program in Northeastern Brazil, between 2001 and 2005. The extended family trial model included 463 relatives of 21 index cases. Relatives were classified as nuclear family (NF: father, mother, and siblings); first degree extended family (N1: grandparents, uncles and aunts, and first cousins); second degree extended family (N2: children of first cousins); extended family (NA: NF+N1+N2); and extended nuclear family (NA1: NF+N1). The presence of HBB*S and other abnormal hemoglobins was confirmed by high-performance liquid chromatography. The association between the presence of HBB*S and other variables was calculated using prevalence ratios and their respective 95 percent confidence intervals, and differences between means were calculated using Student's t test with a 5 percent significance level. RESULTS: Of relatives, 81 percent had no knowledge of sickle-cell anemia and HBB*S was present in 114 family members. A total of 53.3 percent of the studied population was considered as of reproductive age, and 80 percent of HBB*S carriers had already had children. Frequency was higher among NF (69 percent), but was also high in N1 (22.8 percent). NA1 screening resulted in the detection of 69 carriers additional (a 172 percent increase). CONCLUSIONS: These results indicate that family screening for the identification of sickle-cell carriers should be extended to first degree relatives.

Treatment of human acute schistosomiasis with oxamniquine induces an increase in interferon-gamma response to Schistosoma mansoni antigens

Patients with acute schistosomiasis were studied before and after oxamniquine treatment. They had been exposed to cercariae 5 to 9 weeks before, and presented compatible clinical manifestations, eosinophilia, and high levels of total IgE. Interferon-gamma (IFN-gamma) and interleukin-4 were measured by ELISA in whole blood samples under soluble egg antigen or soluble adult worm preparation stimulation. After treatment, the reduction of leukocytosis and eosinophilia were not significant, but total IgE levels decreased significantly, in contrast to IFN-gamma levels that were significantly increased. The oxamniquine treatment of acute schistosomiasis patients is followed by an improvement of a Th1 response in vitro. If this response has a protective aspect is unknown, and some investigations need to be realized.