Increased cell-free viral DNA in fatal cases of chronic active Epstein-Barr virus infection

We have studied the nature of Epstein-Barr virus (EBV) infection in 33 pati ents with chronic active EBV infection. The study population included 14 pa tients with fatal chronic EBV infection and 19 patients with nonfatal chron ic EBV infection, as well as 18 patients with acute EBV-induced infectious mononucleosis and 10 healthy controls. EBV DNA was measured in serum or pla sma samples from the patients by semiquantitative polymerase chain reaction -based assay. EBV DNA was detected in serum or plasma samples from 62% (9/1 4) of patients with fatal chronic active EBV infection. In contrast, only 1 1% (2/19) of patients with nonfatal chronic active EBV infection and 11% (2 /18) of patients with infectious mononucleosis displayed EBV DNA. None of t he healthy controls tested positive. Cell-free circulating EBV DNA may repr esent an important feature of chronic active EBV infection and may provide a useful tool to monitor the severity of this illness.