Lymphocyte apoptosis in newborns with neonatal sepsis

Abstract

Aim. To assess the lymphocyte apoptosis intensity in children with neonatal sepsis. Methods. Lymphocyte apoptosis was assessed in 20 children [of them 16 (80%) prematurely born] with late neonatal sepsis. Bacteriology tests allowed to identify the causetive agent for sepsis in 9 (45%) cases - Staphylococcus haemolyticus in 3 cases, Klebsiella - in 4 cases, Candida - in 2 cases. The control group consisted of 10 healthy newborns. Lymphocyte apoptosis was assessed by determining the amount of mitochondrial transmembrane potential (ΔΨm). Lymphocytes were stained with fluorochrome DiOC 6. Results were obtained by flow cytometry. A decrease in mitochondrial potential value was defined as the reduction of fluorochrome DiOC 6 fluorescence . This parameter is one of the earliest signs of apoptosis. Results. An increased apoptosis was revealed, which was manifested by an increase in the number of cells with reduced membrane potential (DiOC-negative cells) in all children with neonatal sepsis. In 50% of sepsis cases (10 newborns) the number of lymphocytes in which apoptosis was triggered was higher by 3,4 times compared to control, in 25% of cases (5 newborns) - by 6 times, in another 25% (5 newborns) - by 13.4 times. Meanwhile, an absolute lymphopenia was observed only in 65% of cases. The most extensive apoptosis was observed in patients with minimal intensity of severe acute inflammatory reaction. Recovery period was characterized by a decrease in apoptosis intensity, seen as the reduction of the number of cells with reduced membrane potential by mean of 1.9 times. Reduced intensity of lymphocyte apoptosis at recovery was associated with lymphocyte count increase in peripheral blood. Conclusion. Acute phase of neonatal sepsis occurs on the background of the increased intensity of lymphocyte apoptosis.

Keywords

neonatal sepsis / lymphocyte apoptosis / immunity

References

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RIGHTS & PERMISSIONS

Khaertynov K.S., Boychuk S.V., Anokhin V.A., Dunaev P.D., Ramazanov B.R., Satrutdinov M.A., Agafonova E.A.