The concentration of IL-6, TNF-α, s-ICAM-1, and EBV DNA load – predictive factors of hepatological complications in children with infectious mononucleosis. A pilot study

Introduction
The aim of the study was to assess the relationship between the concentration of pro-inflammatory cytokines such as interleukin 6 (IL-6), tumour necrosis factor α (TNF-α), soluble intercellular adhesion molecule 1 (s-ICAM-1), and Epstein-Barr virus (EBV) DNA viraemia in children with infectious mononucleosis and hepatitis.

Material and methods
The Epstein-Barr virus DNA load in the plasma of 36 immunocompetent patients aged 2.5–18 years with a symptomatic (sore throat, cervical lymph node enlargement, fatigue, and fever), antibody-confirmed EBV primary infection was assessed using a quantitative real-time polymerase chain reaction assay. The concentration of IL-6, s-ICAM-1, and TNF-α in serum was determined using enzyme-linked immunosorbent assay tests.

Results
In a group of patients with infectious mononucleosis caused by EBV and viraemia > 3.5 log10 copies/ml, shorter duration of symptoms, and higher serum levels of s-ICAM-1 and C-reactive protein (CRP) were confirmed. In group of children with EBV hepatitis and CRP > 5 mg/l, levels of s-ICAM-1, γ-glutamyl transpeptidase activity, count of total white blood cells and lymphocytes, and EBV DNA load were significantly higher than in patients with CRP < 5 mg/l. Among patients with EBV hepatitis the increase of s-ICAM-1 concentration correlated with the increase of IL-6 and TNF-α serum levels.

Conclusions
The results suggest a higher risk of cholestatic complications in children with elevated CRP level. They indicate that EBV DNA viraemia in conjunction with an s-ICAM-1, IL-6, and TNF-α assessment may be helpful in selecting patients requiring hospitalization.