SERUM CYTOKINE LEVELS IN INFECTIOUS-MONONUCLEOSIS AT DIAGNOSIS AND CONVALESCENCE

Infection with the Epstein-Barr virus (EBV) is common worldwide. A sig nificant number of infected individuals develop infectious mononucleos is (IM). IM is manifested in most patients as a benign disease with mi ld symptoms. However, serious complications may develop in a subset of patients. Because EBV-infected B lymphocytes produce various cytokine s that may provide the cells with a proliferative advantage, cytokine concentrations in serum samples taken from IM patients were measured i n order to identify the cytokines responsible for the clinical manifes tations of the disease. The concentrations of interleukin-1 beta (IL-1 beta), IL-2, IL-6, IL-8, IL-10, tumor necrosis factor-alpha (TNF-alph a), and lymphotoxin (LT) were measured using an enzyme-linked immunoso rbent assay (ELISA) in serum obtained from 14 IM patients during the a cute phase of the disease and during convalescence, 5 patients with id entical clinical manifestations who did not have IM (sick controls), a nd 11 healthy volunteers. It was found that the serum levels of TNF-al pha and IL-6 were significantly high in patients with acute IM compare d with the serum levels in healthy individuals (P = 0.008 and P < 0.00 1, respectively) but returned to normal at convalescence (P = 0.009 an d P = 0.005 respectively). However, whereas TNF-alpha concentrations w ere significantly higher (P = 0.04) in patients with acute IM than in the sick controls, no significant difference in IL-6 concentrations wa s found between the two groups of patients. Changes in IL-10 concentra tion were not statistically significant, and IL-1 beta, IL-2, IL-8, an d LT were detected only sporadically. The data in this study suggest t hat TNF-alpha may have a specific role in causing the clinical manifes tations of IM. Further studies should determine the clinical significa nce of TNF-alpha inhibition in IM.