Varicella-zoster virus DNA in recurrent aphthous ulcers.

The present study was undertaken to examine for varicella-zoster virus (VZV) constituents in recurrent aphthous ulcers (RAU). Smears and biopsies of ulcers 0-3 days old were obtained from 20 otherwise healthy minor/major RAU patients and from two patients with Behçet's syndrome. VZV could not be cultivated from any of the biopsies, all smears were negative for VZV antigen, and in situ hybridization on the five samples tested was negative for VZV nucleic acid. DNA extracted from biopsies, however, yielded positive polymerase chain reaction (PCR) products in all cases with one primer set of the protein kinase 66 (PK66). Ten control biopsies from non-RAU subjects yielded no PCR products apart from the sample from AP, who obtained the biopsies, and from HOM, who performed the PCR, suggesting that the DNA had been passed on from the patients. Other parts of the PK66 gene and of thymidine kinase 36 yielded no products. Although the consistent presence of VZV DNA in RAU might suggest a pathogenetic implication, the potential presence and possible pathogenetic importance of other herpesviruses cannot be excluded.