RESUMO
Human papilloma virus (HPV) is postulated as a risk factor in the etiology of some specific mucosal pathologies in the head and neck regions. Despite the frequent use of p16(INK4a) as a surrogate marker for HPV-infection, there is still controversy with respect to its reliability. This study has been undertaken to assess the potential role of p16(INK 4a) and Ki-67 expression in HPV-related lesions. The study was conducted on 71 specimens of oral, tonsillar and laryngeal lesions which comprised 25 dysplasia and 46 papilloma specimens. Specimens were immunohistochemically stained for p16(INK4A) and Ki-67 proteins. HPV DNA was determined by one step multiplex polymerase chain reaction. HPV DNA was detected in 33.8% of all lesions. Tonsil and larynx lesions showed significant differences with oral lesions for HPV positivity (p < 0.001). p16(INK 4a) over-expression was seen in 56.5% of papilloma and 60% of dysplasia specimens. HPV status showed a positive correlation with p16(INK 4a) expression in tonsillar dysplasias (p < 0.001). p16(INK 4a) expression may have a value as a marker in high risk HPV induced dysplasias, but not in low risk infected lesions. The proliferation index is not related to HPV-induced lesions and may be evaluated as an independent marker in head and neck premalignant lesions.
Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/biossíntese , Neoplasias de Cabeça e Pescoço/virologia , Antígeno Ki-67/biossíntese , Papillomaviridae/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Human papilloma virus (HPV) is postulated as a risk factor in the etiology of some specific mucosal pathologies in the head and neck regions. Despite the frequent use of p16INK4a as a surrogate marker for HPV-infection, there is still controversy with respect to its reliability. This study has been undertaken to assess the potential role of p16INK 4a and Ki-67 expression in HPV-related lesions. The study was conducted on 71 specimens of oral, tonsillar and laryngeal lesions which comprised 25 dysplasia and 46 papilloma specimens. Specimens were immunohistochemically stained for p16INK4A and Ki-67 proteins. HPV DNA was determined by one step multiplex polymerase chain reaction. HPV DNA was detected in 33.8% of all lesions. Tonsil and larynx lesions showed significant differences with oral lesions for HPV positivity (p<0.001). p16INK 4a over-expression was seen in 56.5% of papilloma and 60% of dysplasia specimens. HPV status showed a positive correlation with p16INK 4a expression in tonsillar dysplasias (p<0.001). p16INK 4a expression may have a value as a marker in high risk HPV induced dysplasias, but not in low risk infected lesions. The proliferation index is not related to HPV-induced lesions and may be evaluated as an independent marker in head and neck premalignant lesions.
El virus del papiloma humano (VPH) se postula como un factor de riesgo en la etiología de algunas patologías de la mucosa, específicas en las regiones de cabeza y cuello. A pesar de usar con frecuencia el p16INK4A como un marcador sustituto para la infección por VPH, todavía existe controversia con respecto a su fiabilidad. Este estudio se ha llevado a cabo para evaluar el papel potencial de la expresión de p16INK 4a y de Ki-67 en las lesiones relacionadas con el VPH. El estudio se realizó en 71 muestras de lesiones orales, tonsilares y laríngeas que comprendían 25 displasias y 46 especímenes de papiloma. Los especímenes fueron teñidos inmunohistoquímicamente para p16INK4a y Ki-67. El ADN del VPH se determinó mediante una PCR multiplex de un paso. ADN del VPH se detectó en el 33,8% de todas las lesiones. Las lesiones de la amígdala y laringe mostraron diferencias significativas con lesiones orales para la positividad de VPH (p <0,001). Sobre-expresión de p16INK 4a se observó en 56,5% de las muestras de papiloma y 60% de las muestras de displasia. El estatus del VPH mostró una correlación positiva con la expresión de p16INK4a en displasias tonsilares (p <0,001). La expresión de p16INK4a puede tener valor como marcador en las displasias inducidas por VPH de alto riesgo, pero no en las lesiones infectadas de bajo riesgo. El índice de proliferación no está relacionado con las lesiones inducidas por VPH y puede ser evaluado como un marcador independiente en las lesiones premalignas de la cabeza y del cuello.