ANALYSIS OF THE TARGET-CELL FOR EPSTEIN-BARR-VIRUS INFECTION IN EPSTEIN-BARR-VIRUS ASSOCIATED HEMOPHAGOCYTIC SYNDROME (EBV-AHS)

Epstein-Barr virus (EBV) infected cells were examined in three cases o f EBV-associated hemophagocytic syndrome (EBV-AHS) by analysis of the heterogensity of terminal repetitive sequences in the EBV genome, indi cating monoclonal expansion of EBV-infected cells in all cases. Involv ement of T lymphold cells was determined by the finding of in situ hyb ridization using [S-35]-labeled RNA probes specific for the small EBV- encoded nuclear RNAs, EBER1 and EBER2, in combination with immunostain ing for the TCR-beta chain, CD45RO, CD20, CD30 and CD68 antigens in th ese three cases. The majority of lymphold cells showing EBER transcrip ts were stained by antibodies against CD45RO and TCR-beta. In contrast , EBER-specific signals were not detectable on B cells or hemophagocyl ic colis. These dats support the concept that subclinical EBV-associat ed T cell proliferation is the primary characteristic of EBV-AHS, rath er than proliferations of hemophagocytosing histiocytes.