Padronização da extração de DNA em papel filtro para a aplicação em amostras suspeitas de infecção perinatal pelo HIV-1

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

AIDS is caused by the human immunodeficiency virus type 1 (HIV-1). The infection by this virus in significantly falling between pediatric patients in the last years, mainly because the special interest of the Brazilian Government to the HIV-1 infected patients, especially the pregnant woman. The perinatal HIV-1 transmission may occur during the pregnancy, at the time of the birth, or after the birth during breast feeding. The diagnosis of HIV-1 infection in adults and children older than 18 months is usually defined by serological assays, which identify specific antibodies against HIV-1. However, the newborn acquire the IgG maternal antibodies during the pregnancy, which can result in a false positive diagnosis. The Brazilian Department of Health suggests that the diagnosis in patients younger than 18 months old could be defined with molecular biology, because these tests usually detects viral particles and not the HIV-1 antibodies. A very efficient test, the polimerase chain reaction (PCR), can define the diagnosis precocious, quick and sensible, and, in addiction, the performance of a second amplification reaction ( Nested-PCR") may elevate the sensibility and specificity of this test. The PCR detects fragments of the viral genoma, however, to obtain satisfactory amplifications, it is necessary a large volume of blood of the newborn. Based on the necessity of precocious diagnosis of HIV-1 and better quality of small blood volume sample, this project aim to standardize the technique of DNA extraction of blood sample obtained with filter paper, with the utilization of FTA Card kits (Life Technologies). To confirm the accuracy of this proposed method, it was applied the "Nested-PCR" technique, previously standardized in our laboratory, based on peripheral blood obtained with EDTA. To perform the PCR and "Nested-PCR", there were utilized four pairs of external (PCR) and internal ("Nested-PCR") primers to genes which flank conserved regions of HIV-1 (gag gene, pol gene and two regions of the env gene). There were studied 71 patients: 43 children with suspicious HIV-1 perinatal infection, 11 children and 14 adults, who were HIV-1 seropositive, and three children HIV-1 negative (control group). The results showed concordance between the two extraction methods studied, corroborating with the literature, which affirms that the DNA extraction obtained with filter paper is a technique that could be applied with success to perform "Nested-PCR" to the diagnosis of children with suspicious HIV-1 perinatal infection

ASSUNTO(S)

aids (disease) reação em cadeia de polimerase aids polymerase chain reaction

ACESSO AO ARTIGO

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