RESUMO
BACKGROUND: Isolates of HPV16 comprise six variants: European (Eu), Asian (As), Asian-American (AA), North American (NA), African-1 (AF1), and African-2 (AF2) with different carcinogenic potentials. Highly reliable automatable techniques for HPV variant genotyping would be helpful to confirm the role of variants in cervical cancer in large epidemiological studies. OBJECTIVE: To validate the performance of a novel assay for identification of HPV16 variants. STUDY DESIGN: The test is a multiplex PCR amplifying four small fragments from the E6 open reading frame (ORF). Variants are identified in a reverse hybridization assay with variant specific probes. The novel assay was compared to sequence analysis of the E6 ORF in 68 clinical samples. In addition, HPV16 variant distribution was studied in 218 cervical samples from women with normal cytology, squamous cell carcinoma (SCC) and adenocarcinoma of countries in Africa, Asia and South-America. RESULTS: There was 95.6% agreement between the test and sequencing. Analysis of the clinical panel including 218 positive samples revealed worldwide distribution patterns of HPV16 variants. Finally, a threefold increased risk for SCC with grouped Eu and As variants in South-American countries as compared to controls was found, although the association was not statistically significant. CONCLUSIONS: The novel assay is a reliable and simple technique, distribution patterns of HPV16 variants in different world regions and disease associations could be established and it may be useful in further epidemiological studies investigating the role of HPV16 variants in cervical carcinogenesis.
Assuntos
Papillomavirus Humano 16/classificação , Papillomavirus Humano 16/isolamento & purificação , Técnicas de Diagnóstico Molecular/métodos , Hibridização de Ácido Nucleico/métodos , Infecções por Papillomavirus/diagnóstico , Reação em Cadeia da Polimerase/métodos , Virologia/métodos , Colo do Útero/virologia , Primers do DNA/genética , Feminino , Genótipo , Papillomavirus Humano 16/genética , Humanos , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/virologia , Proteínas Repressoras/genéticaRESUMO
A group of 208 human immunodeficiency virus (HIV)-infected women in Brazil were studied for the presence of human papillomavirus with the general SPF(10) PCR primer set. Virtually all (98%) women were found positive for human papillomavirus (HPV) DNA. Genotyping by the reverse hybridization line probe assay (HPV-LiPA) revealed a high prevalence of multiple genotypes (78.9% of the cases), with an average of 3.1 genotypes per patient (range, 1 to 10 genotypes). HPV 6 was the most prevalent genotype and was observed in 80 (39.2%) patients, followed by types 51 (31.9%), 11 (26.0%), 18 (24.0%), and 16 (22.5%). Of the genotypes detected, 40.9% were low-risk genotypes. Twenty-two (10.5%) patients showed normal (Pap I) cytology, 149 (71.6%) patients had inflammation (Pap II), and 28 patients (13.4%) had a Pap III score. The prevalence of high-risk genotypes increased with the cytological classification. There were no significant associations between the number of HPV genotypes detected and the cytological classification, HIV viral load, and CD4 count in these patients. In conclusion, the highly sensitive SPF(10) LiPA system shows that a very high proportion of HIV-infected women in Brazil are infected with HPV and often carry multiple HPV genotypes.