Interferon and tumor necrosis factor production by peripheral blood leukocytes of patients with infectious mononucleosis.

: Blood samples from 29 patients with infectious mononucleosis (IM) in phases of acute disease and convalescence were obtained. Interferon alpha (IFN-alpha) and tumor necrosis factor alpha (TNF-alpha) activity was detected in sera of patients both in: acute and convalescence phase, however when IFN titers were higher in the acute than convalescence phase, TNF titers were the highest in convalescence. In the whole blood assay Newcastle disease virus (NDV), phytohemagglutinin (PHA) and concanavalin A (ConA) and lipopolysaccharide (LPS) were used as cytokine inducers. A significant decrease in IFN titer induced in vitro with NDV, PHA and ConA was observed in blood leukocytes of patients in the acute IM phase. In convalescence the ability of blood leukocyte of IM patients to produce IFN returned to normal, comparable with control. However, blood leukocytes of IM patients in the acute phase produced more TNF in response to LPS than in convalescence. The role of the observed overproduction of TNF in the course of IM similar to that in HIV infection should be elucidated.