[Interrelationship between Epstein-Barr virus and Sjögren's syndrome].

We designed a specific primer of EB virus Bam W fragment and EBV DNA sequence by using the polymerase chain reaction (PCR) to amplify the EBV DNA sequences and then performing the hybridization analysis (dot blot and Southern transfer) with a gamma 32P end-labelled internal oligonucleotide probe. There was a significantly higher positive rate of 24% (7/29) for the labial glands of Sjögren's syndrome patients than 68% (20/29) for gamma 32P Bam W probe. In situ DNA hybridization, with (alpha 35S) DCTP labelled EBV DNA probe, the EBV genomes were demonstrated in the labial glands of the Sjögren's syndrome patients (16/28). Moreover, the elevated content of EBV DNA was identified in those with more severe destruction of labial glands. We conclude that EBV has a normal site of latency at salivary glands in a nonpathogenic state, and may be reactivated in Sjögren's syndrome patients and play a role in the pathogenesis of this disease. The great sensitivity of PCR and the ability to analyze very small tissue biopsies (fresh or paraffin-embedded) make this technique applicable to clinical diagnosis.