Financial s...

Infections of T cells and natural killer (NK) cells play a central role in the pathogenesis of chronic active Epstein-Barr virus (CAEBV) infection. To characterize the virologic and cytokine profiles of T cell–type and NK cell–type infection, 39 patients with CAEBV infection were analyzed. Patients with T cell–type infection had higher titers of immunoglobulin G against early and late EBV antigens, suggesting lytic cycle infection. However, the pattern of EBV gene expression was latency type II; BZLF1, which is a hallmark of lytic cycle infection, could not be detected in any patients, regardless of infection type. Patients with CAEBV infection had high concentrations of proinflammatory, T helper cell type 1, and anti-inflammatory cytokines. The cy-tokine profile in patients with NK cell–type infection was similar to that in patients with T cell–type infection, but the concentration of IL-13 was high in patients with NK cell–type infection. These findings should help to clarify the pathogenesis of CAEBV infection and facilitate the development of more-effective treatments. Epstein-Barr virus (EBV) is a ubiquitous virus that in-fects most individuals by early adulthood. Primary EBV infection is usually asymptomatic but sometimes pro-gresses to infectious mononucleosis, which resolves spontaneously after the emergence of EBV-specific im