New approach to human high-risk papillomavirus (HR-HPV) genotyping.

Human high-risk papillomaviruses (HR-HPVs) are involved in the induction of invasive cervical cancer. The aim of this study was to introduce a simple, semi-automated and reproducible approach suitable for HR-HPV detection in clinical practice. The procedure is based on DNA isolation, nested polymerase chain reaction, single strand conformational polymorphism and evaluation of HR-HPV genotypes with Gel-Pro software. The clinical performance of the new approach was assessed in two different patient materials: 1) cervical smears with cytological classification Pap2-3 or Pap3 lacking nuclear atypia (anisonucleosis and polychromasia) or koilocytotic atypia and without any previous therapy 2) formalin-fixed, paraffin-embedded cervical carcinoma and lymph node sections. Using the new approach we detected HR-HPV DNA in 64% patient samples cytologically classified as Pap2-3 or Pap3 respectively and in 80% formalin-fixed, paraffin-embedded lymph node sections histologically classified as lymph nodes without carcinoma cell infiltration. The combination of methods described in this study results in increased sensitivity of HR-HPV identification allowing detection of HPV DNA in a very small amount of target DNA so that it can be widely used in distinguishing the pre- malignant lesions and in determination of invading carcinoma cells to lymph nodes in patients with advanced cervical cancer. The new approach is useful in unambiguous HR-HPV genotyping even in double-HPV infection.