Abstract
Activated lymphocytes morphologically change into large aberrant cells known as atypical lymphocytes (atyLy). AtyLy are seen
in various non-neoplastic conditions such as viral infection of Epstein-Barr virus, cytomegalovirus and hepatitis viruses. These
activated cells release various cytokines or soluble receptors such as soluble interleukin-2 receptor (sIL-2R) and Fas-receptor
(Fas-R). Accordingly, we measured serum sIL-2R in 25 pediatric patients. The data and other hematological/biochemical parameters
were analyzed by the statistical processing method of Principle Component Analysis (PCA). 23 out of 25 patients with
atypical lymphocytosis-related conditions (atyLy/lymphocyte ratio > 5%) were found to have higher serum sIL-2R levels than the
cut-off-value of 400 U/mL. The correlation between sIL-2R and the atyLy/lymphocyte ratio was the best indicator for discriminating
the severity of disease. The first component (contribution ratio: 0.384) of PCA showed that lymphocyte activity was mostly
represented by sIL-2R, lactate dehydrogenase, white blood cell count, lymphocyte count, lymphocyte percentile and atyLy/lymphocyte
ratio.
Conclusively, these findings suggest a strong correlation between serum sIL-2R level and atypical lymphocytosis.
