Human papillomavirus (HPV) infections are strongly associated with the development of cervical intraepithelial neoplasias and invasive cervical cancer. Polymorphisms in cytokine-encoding genes and behavioural cofactors could play an important role in protecting an individual against viral infections and cancer. Here, we investigated whether IL-6 -174 G>C, IL-8 +396 G>T, and TGF-β1 +869 G>C and +915 G>C polymorphisms were associated with susceptibility to HPV infection in women from north-east (Pernambuco) Brazil. We analysed 108 healthy uninfected women (HC) and 108 HPV-positive women with cervical lesions. Genetic polymorphisms were assessed using Sanger sequencing and polymerase chain reaction-restriction fragment length polymorphism. Comparison of the distribution of the genotypic and allelic frequencies of the IL-18 +396 T>G polymorphism between HPV infected woman an uninfected controls showed that the GG genotype and G allele were both more frequent in the HC group, and were associated with protection from HPV infection (p = 0.0015; OR = 0.29 CI95% = 0.13-0.61; p = 0.0005; OR = 0.45 CI95% 0.29-0.7, respectively). Individuals from the control group could have previously had HPV infection that was spontaneously eliminated; however, it was undetectable at the time of sample collection. Based on our findings, we hypothesize that the IL-8 +396 G>T polymorphism could interfere with susceptibility to HPV infection, by modulating the ability of immune system to fight the virus.

OBJETIVO: comparar três métodos para detecção do HPV e determinar a prevalência dos genótipos encontrados. MÉTODOS: um total de 120 amostras de raspagem da região cervical de mulheres portadoras de neoplasia intraepitelial cervical foram analisadas pela reação em cadeia da polimerase convencional, usando os sistemas de primers MY09/11, GP05+/06+ e pela Nested-PCR. As amostras foram submetidas à extração de DNA e, logo após, amplificadas com os primers GH20 e PC04 (β-globina) para verificação da qualidade do DNA obtido e pela reação em cadeia da polimerase convencional e Nested-PCR. Os fragmentos amplificados foram visualizados em gel de agarose a 1,2%, corados com Blue Green Loading Dye I. As amostras positivas foram sequenciadas usando o sequenciador automático de DNA "MegaBACE 1000". Para análise estatística foram utilizados os teste do Χ2 e o de Fisher com nível de significância de 5%. RESULTADOS: quinze amostras não se amplificaram para os primers de β-globina, sendo eliminadas do estudo. Das amostras restantes, 40% (42/105) foram positivas para os primers MY09/11, 98% (103/105) para os primers GP05+/06+ e 92% (97/105) para Nested-PCR. Considerado as técnicas MY09/11 e GP05+/06+, foi possível observar 100% de amostras positivas para o HPV. Neste estudo, a prevalência dos genótipos foi de 58, 23, 5, 4 e 3% para HPVs 16, 18, 31, 33 e 56, respectivamente. Os HPV 67 e 83 apresentaram 2% e os HPV 6, 11, 58 e candHPV85, 1% cada. A prevalência dos genótipos neste estudo está de acordo com o reportado em todo o mundo (IC95%=0,4657-0,8976). CONCLUSÕES: para obter resultados mais confiáveis, é necessário o uso de mais que um sistema de primers para detecção do HPV. Acredita-se que as três técnicas estudadas são importantes e adequadas para o diagnóstico clínico do HPV quando apropriadamente combinadas.

PURPOSE: to compare three methods for the detection of HPV infection and to determine the prevalence of the genotypes found. METHODS: a total of 120 cervical scrape samples from patients with cervical intraepithelial neoplasia were analyzed by the conventional polymerase chain reaction using the MY09/11 and GP05+/06+ primers, and by the Nested polymerase chain reaction. The samples were subjected to DNA amplification with the GH20 and PC04 primers (β-globin) to verify DNA quality and also by polymerase chain reaction and Nested polymerase chain reaction. The amplicons were visualized in 1.2% agarose gel stained with Blue Green Loading Dye I. Positive samples also were sequenced using the automatic DNA sequencer "MegaBACE 1000". The Χ2 and Fisher tests were used for statistical analysis with the level of significance set at 5%. RESULTS: fifteen samples were eliminated from the study because they failed to amplify the β-globin gene. Of the remaining samples, 40% (42/105) were positive using primers MY09/11, 98% (103/105) using primers GP05+/06+, and 92% (97/105) using Nested-PCR. With the MY09/11 and GP05+/06+ techniques, it was possible to obtain 100% HPV-positive samples. In this study, the prevalence of the genotypes found was 57, 23, 5, 4 and 3% for HPV genotypes 16, 18, 31, 33 and 56, respectively. HPVs 67 and 83 were present in 2%, and genotypes 6, 11, 58 and candHPV85 were present in 1% each. The prevalence of the more common genotypes (HPV 16 and 18) in this study agrees with that reported worldwide (IC95%=0.4657-0.8976). CONCLUSIONS: to obtain more reliable results, it is necessary the use of more than one primer system to detect HPV infections. We believe that the three techniques studied are important and suitable for the clinical diagnosis of HPV, when they are appropriately combined.