CHRONIC ACTIVE EPSTEIN-BARR-VIRUS DISEASE IN A CASE OF PERSISTENT POLYCLONAL B-CELL LYMPHOCYTOSIS

Persistent polyclonal B-cell lymphocytosis (PPBL) is a rare haematolog ical disorder. It is characterized by activated and morphologically at ypical B lymphocytes and polyclonal IgM production and has been associ ated with female sex, cigarette smoking, and HLA-DR7 expression. We re port a case of PPBL with intermitting symptoms compatible with a chron ic fatigue syndrome, recurrent erythema nodosum and multiforme. Serolo gical findings suggest-ed a chronic active Epstein-Barr virus (EBV) in fection. Messenger RNA of EBV immediate early gene transactivation BZL F1 was detected in peripheral blood lymphocytes by reverse transcripta se PCR indicating a persistent replication of the virus. Over 2 years of observation we detected varying numbers of atypical lymphocytes. Th ese cells hybridized with a probe specific for the EBV internal repeat region (BamHI W) which indicates a productive infection. Of interest, no reaction was observed with a probe specific for the latency-associ ated small RNAs (EBERs). The immunological phenotype of the polyclonal B cells was similar to B-cell lines immortalized by EBV in vitro, exp ressing a number of activation molecules (CD23, CD25, CD54) and the bc l-2 protein. In summary, our findings suggest that persistent EBV repl ication might be crucial in the development of lymphoproliferative dis orders such as PPBL.