Análise dos Sorotipos do VHC Identificados em Pacientes da Cidade de São Paulo, Através de Método Imunoenzimático. / Analysis of serotypes of HCV in patients from the city of São Paulo, by means of a enzyme-immunoassay method.

AUTOR(ES)
DATA DE PUBLICAÇÃO

1999

RESUMO

CAVALHEIRO, N.P. Analysis of serotypes of HCV in patients from the city of São Paulo, by means of a enzyme-immunoassay method. São Paulo, 1999. 97p. Dissertação de Mestrado - Faculdade de Medicina, Universidade de São Paulo. With the objetive of analysing the prevalence of the different types of Hepatitis C Virus (HCV) in a population of chronic carriers of HCV, through a sorologic method (MUREX HCV Serotyping Assay), 219 patients were studied who showed a positive polymerase chain reaction. This sera were submitted to immunoenzimatic tests for the detection of antibodies in relation to HCV types 1, 2,3,4,5 and 6. The samples were diluted and incubated in the presence of heterologous competing peptides, with microwells coated with serotype-specific antigens of HCV. Of the 219 patients, it was possible to detect the HCV serotype in 166, revealing a sensitivity of 75.8%. The results showed a predominance of type 1 (70.0%) in our medium, followed by type 3 (22.3%) and type 2 (4.2%). Serotypes 4 and 5 were present in 1.8% of the patients, but always associated with serotype 1. These samples, in spite of fulfilling the prerequisites of validity for testing, showed a very high optical density reading for all types of viruses tested, including positive and negative controls. The possibility of cross reactions in these cases should be considered. Confirmation by genotyping and a more detailed investigation on the origin and mode of acquisition of the HCV of these patients should be researched. Type 6 was not confirmed in any of the samples tested and probably was not present in this particular collection. The epidemiological parameters evaluated were: age, sex and means of transmission. Of the 166 patients diagnosed with the HCV, 108 (65.1%) were men and 58 (34.9%) were women. The age of the patients varied from 12 to 73 years, the average being 41.1 years. The means of transmission mentioned were blood transfusion in 52 (31.3%) cases, intravenous drug use in 18 (10.8%) cases, by tatoos in 8 (4.8%) cases, 6 (3.6%) cases were sexually transmitted, 3 (1.8%) were by accident with a needle, 2 (1.2%) through work in the health field, one (0.6%) through acupunture and one by being hemophiliac. Sixty one (36.7%) patients were not able to offer any risk factor which justified the acquisition of the HCV infection. No significant difference was verified among the different types of HCV found and the different epidemiological parameters studied. The predominance of types 1, 3 and 2 is compatible with other genotyping studies which involved Brazilian samples, particularly in the city of São Paulo. The samples which showed high or low dense optical reading for all the wells of the same samples tested even the positive or negative controls, suggested confirmation by sequecing or genotyping. The praticality obtained by the HCV serotyping test, in spite of the fact that it does not identify the sub type, can be useful in clinical pratice and helpful in the prognostication of the disease, not needing the tecnology demanded by the tests which involve molecular biology.

ASSUNTO(S)

elisa serotype diagnóstico hcv sorotipos diagnostic hcv elisa

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