Context: The detection and typing of high-risk and low-risk human papillomavirus (HPV) in archival formalin-fixed, paraffin-embedded tissues by nucleic acid amplification testing is an important adjunct to immunohistochemical staining in evaluation of squamous cell proliferations of the oropharynx, larynx, and anal canal.
Objective: To evaluate semiautomated, xylene-free extraction from formalin-fixed, paraffin-embedded tissues combined with laboratory-developed HPV L1 sequencing and type-specific HPV 6, 11, 16, and 18 real-time polymerase chain reaction for identification and typing of HPV in the clinical laboratory.
Design: We evaluated the adequacy of extraction using β-globin amplification and compared L1 sequencing and real-time polymerase chain reaction methods for typing accuracy using 68 formalin-fixed, paraffin-embedded tissues, including 56 anorectal biopsy or surgical resection specimens and 12 laryngeal papilloma specimens from patients with recurrent respiratory papillomatosis.
Results: Adequate DNA was obtained from 68 of 68 specimens analyzed and all were HPV positive. In 47 cases where L1 sequencing demonstrated that the predominant HPV type was 6, 11, 16, or 18, type-specific, real-time polymerase chain reaction provided concordant results. Sequencing revealed additional low-risk (HPV 40) and high-risk HPV types (HPV 31, 33, 56, and 58) in anorectal specimens, whereas HPV 6 or 11 were the types found in laryngeal papillomas.
Conclusion: Both L1 sequencing and type-specific, real-time polymerase chain reaction are suitable methods for routine HPV testing of formalin-fixed, paraffin-embedded tissues in a clinical laboratory setting.