2023 Volume 35 Issue 1 Pages 19-26
The pathogenesis of laryngeal papilloma (LP) is unclear. The Nanosuit-CLEM (correlative light and electron microscopy) method allows for easy scanning electron microscopy. We observed the process of HPV particle formation by the Nanosuit-CLEM method to visualize the life cycle of HPV in LP and to examine its clinical significance. Sixty-nine LP samples (30 patients) obtained from September 2005 to October 2021 were included in the present study. HPV was detected using PCR and the type was determined. Immunohistochemistry (IHC) was performed for p16, HPV-L1, and HPV-E4. We used NanoSuit-CLEM and transmission electron microscopy (TEM) to examine the samples. LP patients were mainly male (n = 25/30, 83.3%). The total number of surgeries in HPV-positive and HPV-negative cases were 3.60 (range: 1–16) and 1.30 (range: 1–3), respectively (p = 0.07). IHC showed that HPV-L1 and HPV-E4 were correlated and expressed on the tumor surface. NanoSuit-CLEM and TEM revealed the presence of HPV particles in HPV-L1 positive nuclei. A small number of HPV particle-like structures were also observed in negative cells adjacent to HPV-L1 positive cells. There was no evidence of HPV particles being released from the nuclei of the topmost cells of the tumor. HPV-L1 IHC-positive cases had a shorter surgical interval (p < 0.01) and more frequent surgeries (p = 0.04). P16 IHC was not associated with disease severity. We visualized the production of HPV particles in LP. Persistent HPV particle infection is associated with the severity of LP.
