A histochemical method for demonstrating papilloma virus infection in paraffin-embedded tissue

Area of Science:

• Histopathology
• Molecular Biology
• Virology

Background:

• Accurate localization of human papilloma virus (HPV) in paraffin-embedded tissues is crucial for diagnosis and research.
• Existing diagnostic methods may have limitations in sensitivity or specificity for detecting HPV-infected cells.

Purpose of the Study:

• To develop and evaluate a novel staining technique for identifying HPV-infected cells within tissue sections.
• To compare the efficacy of the new stain against established methods like indirect immunoperoxidase.

Main Methods:

• Tissue sections were treated with deoxyribonuclease to degrade cellular DNA.
• Sections were stained using the Feulgen stain with a light green counterstain, exploiting differential DNA degradation.
• Comparison with indirect immunoperoxidase staining and confirmation by electron microscopy.

Main Results:

• The Feulgen stain successfully differentiated HPV-infected cells (magenta nuclei) from uninfected cells (green nuclei).
• High positive rates were observed for various HPV-associated lesions: plantar warts, verruca vulgaris, laryngeal papilloma, and condylomata acuminata.
• The Feulgen stain demonstrated superior sensitivity compared to immunoperoxidase for laryngeal papilloma and condylomata acuminata.

Conclusions:

• The developed Feulgen staining method is effective for visualizing HPV-infected cells in paraffin-embedded tissues.
• This technique offers a valuable tool for the histopathological diagnosis of HPV infections.
• Further investigation is warranted to understand the specific mechanism of viral DNA resistance to degradation and potential non-viral positive staining.