Cortisol concentration as a marker of adaptation processes in children with infectious mononucleosis at different periods of the disease

BACKGROUND: Infectious mononucleosis is an acute infectious disease caused by Epstein–Barr virus. This virus replicates in B-lymphocytes but may be as well found in the epithelial cells of pharynx and parotid ducts. Its typical symptoms include fever, lymphadenopathy and herpetic angina, the endocrine system may also be involved in the pathologic process. AIM: The aim of the study is the change in cortisol levels in children of different sex and age during the peak and convalescence of infectious mononucleosis caused by the Epstein–Barr virus. MATERIALS AND METHODS: Under observation were 94 children aged 1 to 17 years, among them from 1 to 5 years — 22%, from 5 to 10 years — 39%, from 10 to 15 years — 27%, from 15 to 17 years — 12%, with a diagnosis of Epstein–Barr virus – mononucleosis moderate severity. The diagnosis was made on the basis of clinical, anamnestic and laboratory data. Studies confirming the diagnosis were carried out in the laboratory of St. Petersburg State Pediatric Medical University. In addition to routine examinations (clinical minimum), determination of M- and G- antibody titers to the Epstein–Barr virus, detection of the Epstein–Barr virus genome in the blood by PCR, and determination of cortisol levels by enzyme-linked immunosorbent assay in blood serum. RESULTS: In all age groups, the cortisol concentration during the peak period was higher than during the convalescence period. At the same time, in girls in groups from 6 to 10 years old and from 11 to 16 years old, this difference was significant (1045.19 ± 111.10 versus 740.97 ± 120.68 nM/l and 977.31 ± 81.40 versus 735.48 ± 113.04 nM/l respectively). In boys of all age groups, the differences were significant and amounted to 1211.30 ± 128.36 versus 864.63 ± 126.90 nM/l in the group from 1 to 5 years old, and 1066.76 ± 39.01 versus 817,90 ± 101,52 nM/l in the age group from 6 to 10 years old, in the age group from 11 to 16 years 950.14 ± 101.54 versus 779.61 ± 125.68 nM/l. CONCLUSIONS: Changes in cortisol levels in children during the peak of infectious mononucleosis depend on the severity of the disease, the presence and nature of complications. The level of cortisol determines various options for adaptation to infectious mononucleosis.