Infection-associated hemophagocytic syndrome : evidence for Epstein-Barr virus gene expression

Autopsy specimens from a patient with infection-associated hemophagocytic syndrome (IAHS) were evaluated for the presence of Epstein-Barr virus DNA and RNA using in situ hybridization. Frozen sections of liver, lymph node, and spleen were probed with EBV Bam HI-H & W, gamma interferon, and SP-65 plasmid DNA as a negative control probe. Hybridization patterns before and after treatment with ribonuclease A were examined. Both EBV probes produced diffuse hybridization throughout the tissues; in addition, there were some foci of extremely heavy concentrations of silver granules. A gamma interferon probe showed evidence of hybridization, but the overall intensity was not as great as with EBV probes. Pretreatment with ribonuclease A dramatically decreased hybridization in all tissues to EBV probes, but hybridization with SP-65 was unaffected. The elimination of EBV hybridization with ribonuclease A pretreatment provides the first evidence of EBV gene expression in an IAHS patient.