RESUMO
Respiratory syncytial virus (RSV) is the most important microbiological cause of lower respiratory tract infection (LRTI) in infants. Mannan-binding lectin (MBL) is believed to play a major protective role in the vulnerable period in infancy where the maternal antibodies have been catabolized, and the adaptive immune system has not yet matured. Mutations in the promoter region and in exon 1 of the gene-encoding MBL result in low serum levels of MBL. MBL deficiency is the most common immunodeficiency on the African Continent with frequencies of the variant alleles up to 0.29. We investigated whether MBL deficiency has an impact on the hospitalization for LRTI caused by RSV in infants from Soweto, South Africa. The cases were ethnic black Africans identified through surveillance for RSV-LRTI at Chris Hani Baragwanath Hospital, Soweto, and the controls were sampled from four immunization clinics in the area. Fifty-five cases and 113 age- and sex-matched controls were identified. Seventy-six per cent were under 6 months of age, and 42% (n = 23) were under 3 months of age. No association was found between low levels of MBL or carriage of variant alleles and LRTI caused by RSV, odds ratio (OR) 1.00 (CI 0.99-1.03) and OR 1.24 (0.73-2.12). We did not find support for the hypothesis that MBL deficiency leads to the hospitalization for LRTI caused by RSV.
Assuntos
Lectina de Ligação a Manose/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sinciciais Respiratórios/imunologia , Infecções Respiratórias/imunologia , Estudos de Casos e Controles , DNA/química , DNA/genética , Feminino , Genótipo , Hospitalização , Humanos , Lactente , Modelos Logísticos , Masculino , Lectina de Ligação a Manose/sangue , Reação em Cadeia da Polimerase , Pobreza , Infecções por Vírus Respiratório Sincicial/sangue , Infecções por Vírus Respiratório Sincicial/virologia , Infecções Respiratórias/sangue , Infecções Respiratórias/virologia , África do Sul , População UrbanaRESUMO
In this review the different methods of antenatal detection of congenital abnormalities are briefly outlined. Modern techniques developed in recent years for the diagnosis of genetic disorders by studying the amniotic fluid are considered in detail. The technique of amniocentesis, its indications, complications and the methods of investigation of amniotic fluid are discussed. The indications for chromosomal analysis of amniotic fluid cells for detecting fetal abnormalities and possible pitfalls are reviewed. The major inborn disorders of lipid and carbohydrate metabolism which can be detected in early pregnancy are tabulated and briefly discussed.
