Detection of human papillomavirus in matched cervical smears and biopsy specimens by non-isotopic in situ hybridisation

Aims: To determine the relative diagnostic sensitivity of non-isotopic
in situ hybridisation (NISH) for the diagnosis of human papillomavirus
(HPV) on matched smears and biopsy specimens; to compare the NISH signal
type in the two samples; and to correlate the NISH data with the
morphological diagnosis. Methods: HPV samples were assayed individually
by NISH with digoxigenin
labelled probes (HPV6, 11, 16, 18, and 33) on routinely collected
paraffin wax embedded cervical biopsy specimens and for high risk HPVs
with a cocktail of similarly labelled probes (HPV16, 18, 33) on matched
smears. These were taken at the same colposcopic examination from 32
patients investigated for an abnormal cervical Papanicolaou (PAP)
stained smear. Results: An HPV signal was present in 18 (56%) biopsy
specimens and in 14 (44%) smears. There was higher concordance of sets
of data in the presence of cytopathic wart virus changes. The
superiority of biopsy over smear in detecting HPV was mainly the result
of examining the entire cervical biopsy specimen rather than cells
scraped from the cervical surface. The NISH signal type in both biopsy
specimen and smear was similar; it has been shown that NISH type 1
signal correlates with episomal viral replication and type 2 and 3
signals with viral integration. Conclusions: These data show that NISH
on cervical smears is a worthwhile primary screen for HPV infection. The
NISH signal types in cervical smears are similar to those previously
described in cervical biopsy specimens.