To investigate if children who later developed acute lymphoblastic leukaemia (ALL) were prenatally infected with HHV-6 and/or EBV, Guthrie cards taken at birth were analysed by PCR. Labeled cloned fragments from the EBV recombinant DNA library were cross hybridized to blots of EcoRI, XbaI, and BamHI restriction endonuclease fragments of herpesvirus pan DNA to identify and map homologous sequences in the herpesvirus pan genome. Viruses in tumor cells also display varying levels of lytic transcription resulting from spontaneous reactivation out of latency. All patients with capsid antibody at the onset ofKS alsohad Epstein-Barr nuclear antigen antibody: 36 patients developed antibody within 3 months after onset of KS; in 10, EBV infection could have been coincidental with the disease. EBV infects human B lymphocytes and certain epithelial cells; infection of lymphocytes is readily accomplished in the laboratory and EBV drives the cells into a state of permanent proliferation. Newer therapies that modulate the host immune response, either by vaccination or the infusion of targeted lymphocytes, have generated significant interest and are already available in some centers. Note: In calculating the moving wall, the current year is not counted.
Enhanced lytic replication results in new infection events and EBV-associated transformation events, and seems to be a risk factor both for malignant transformation and the development of autoimmune diseases. The risk factors associated with cytomegalovirus infection included breast feeding, fewer children in household, and care by a babysitter. In addition, in SLE patients EBV may cause defects of B-cell tolerance checkpoints because latent membrane protein 1, an EBV-encoded viral oncoprotein can induce BAFF, a B-cell activating factor that rescues self-reactive B cells and induces a lupus-like autoimmune disease in transgenic mice.