Analysis of the polymerase chain reaction in the detection of herpesvirus DNA from fixed and stained tissue sections

The polymerase chain reaction (PCR) is a molecular diagnostic technique that has been applied to many infectious processes. Stained and unstained Tzanck smears, vesicle fluid swabs, and crusts have all been used as the source for template DNA for the PCR to document evidence of herpes simplex virus and varicella-zoster virus infection. Thirty-five cases with histologic evidence of acute herpesvirus infection were retrieved from archival tissue blocks that were up to 5 years old. Paraffin and hematoxylin-eosin-stained tissue sections obtained from routinely prepared glass slides from these cases were then examined for herpesvirus DNA using the PCR.

The PCR-detected herpesvirus DNA from 34 (97.1%) of 35 paraffin tissue samples. Herpes simplex virus and varicella-zoster virus DNA were detected in eight and 26 of these cases, respectively. For hematoxylin-eosin-stained tissue samples, PCR detected herpesvirus DNA sequences in 16 (45.7%) of 35 cases. Herpesvirus DNA was isolated from paraffin tissue sections and recently prepared hematoxylin-eosin-stained tissue samples obtained from archival tissue blocks that were up to 5 and 2 years old, respectively.

The PCR can detect herpesvirus DNA in extremely high yield from unstained paraffin-embedded tissue samples with histologic evidence of acute herpesvirus infection that are up to 5 years old. Herpesvirus DNA can also be identified in approximately 50% of these cases from hematoxylin-eosin-stained tissue sections obtained from routinely prepared glass slides.