Revista Brasileira de Ginecologia e Obstetrícia (Feb 2004)
Tipagem e estado físico de papilomavírus humano por hibridização in situ em lesões intra-epiteliais do colo uterino Human papillomavirus typing and physical state by in situ hybridization in uterine cervix intraepithelial lesions
Abstract
OBJETIVO: realizar estudo molecular (hibridização in situ) de pacientes com lesões intra-epiteliais do colo uterino, visando investigar a freqüência e o estado físico do papilomavírus humano (HPV). MÉTODOS: cortes histológicos de biopsias do colo uterino de 84 pacientes foram avaliados pela hibridização in situ, com sonda de amplo espectro, que permite identificação dos HPVs dos tipos 6, 11, 16, 18, 31, 33, 35, 39, 42, 45 e 56, e com sondas específicas para HPV dos tipos 6, 11, 16, 18, 31 e 33. Os padrões físicos de marcação do DNA dos HPV encontrados foram: epissomal, quando todo o núcleo ficou corado pela biotina (marrom); integrado, onde se visualizaram um ou dois pontos marrons no núcleo hibridizado, ou misto, com a associação dos dois padrões anteriores. Das 84 pacientes avaliadas, 31 (36,9%) tinham lesões intra-epiteliais de baixo grau (LIE-BG) e 53 (63,1%) tinham lesões intra-epiteliais de alto grau (LIE-AG) ao exame histológico. Para a análise estatística foi empregado o teste exato de Fisher. RESULTADOS: do total dos casos, 46 (54,7%) foram positivos para DNA de HPV pela sonda de amplo espectro. Na tipagem dos vírus, o HPV-16 foi mais freqüente nas LIE-AG, com 12 casos - 22,6% (pPURPOSE: to carry out a molecular study (in situ hybridization) on patients who present intraepithelial lesions of the uterine cervix, and to assess the frequency and the physical state of the human papillomavirus (HPV). METHODS: histological sections of biopsies of the uterine cervix from 84 patients were evaluated by in situ hybridization, with a broad-spectrum probe, which allows the identification of the HPV types 6, 11, 16, 18, 31, 33, 35, 39, 42, 45, and 56 and with specific probes for HPV types 6, 11, 16, 18, 31, and 33. The physical patterns of HPV DNA found were: episomal, when the entire nucleus stains with biotin (brown); integrated - one or two brown points in the hybridized nucleus, or mixed, associating both patterns. Of the 84 patients evaluated, 31 (36.9%) had low-grade squamous intraepithelial lesions (LSIL), and 53 (63.1%) had high-grade squamous intraepithelial lesions (HSIL) on histological examination. Fisher's exact test was used for the statistical analysis. RESULTS: considering all the cases, 46 (54.7%) were positive for HPV DNA with the broad-spectrum probe. Regarding typing, HPV-16 was the most frequent in HSIL (12 cases - 22.6% - p<0.05). The frequencies of the other HPV types did not show statistically significant differences between the LSIL and HSIL cases. By physical condition assessment of the HPV DNA, the percentage of the episomal (most common in LSIL) and integrated patterns showed no significant differences between the two groups; the mixed HSIL type prevailed when compared to LSIL: 26.4 and 3.2%, respectively (p<0.01). The physical condition of the HPV DNA, integrated in the host cell, was more frequent in the most severe cases. CONCLUSIONS: HPV-16 was the most frequent in HSIL cases. The frequencies of the other HPV types did not show statistically significant differences between the LSIL and HSIL cases. The physical condition of the HPV DNA, integrated in the host cell, was more frequent in the more severe cases.
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