Expression of T subsets and mIL-2R in peripheral blood of newborns with hypoxic ischemic encephalopathy

Background  Infantile and undifferentiated immune cells in the pathogenesis of neonates with HIE have been studied in recent years. This study was undertaken to observe the expression level of T subsets and membrane interleukin-2 receptor (mIL-2R) in the peripheral blood of newborns with hypoxic ischemic encephalopathy (HIE) and its clinical manifestations. Methods  The peripheral blood mononuclear cells (PBMCs) of newborns with HIE and normal controls were isolated by the routine Ficoll-Hypaque method, and the rates of CD₃ ⁺, CD₄ ⁺, CD₈ ⁺, CD₄ ⁺/CD₈ ⁺ and mIL-2R induced and not induced by phytohemagglutinin (PHA) were detected by biotin-streptavidin (BSA) at the first, third and seventh day after birth. Results  At the first day after birth, the positive rates of CD₃ ⁺, CD₄ ⁺, CD₈ ⁺, CD₄ ⁺/CD₈ ⁺ and mIL-2R induced and not induced by PHA were (37.4±6.7)%, (29.4±6.9)%, (16.7±3.3)%, 1.8±0.5, (3.6±1.1)% and (20.9±4.8)%, respectively. Significant differences were observed between the HIE group and the normal controls (P<0.01-P<0.05). At the third day after birth, the positive rates of CD₃ ⁺, CD₄ ⁺, CD₈ ⁺, CD₄ ⁺/CD₈ ⁺ and mIL-2R induced and not induced by PHA were (41.0±7.4)%, (35.8±6.9)%, (22.6±4.5)%, (1.7±0.5), (3.9±1.2)%, and (22.8±5.1)%, respectively. There were significant differences between the HIE group and the normal controls (P<0.05). At the seventh day after birth, the positive rates of CD₃ ⁺, CD₄ ⁺, CD₈ ⁺ were (41.8±6.1)%, (36.4±5.1)% and (25.6±4.3)%, respectively. There was significant difference between the HIE group and the normal controls (P<0.05). The ratio of CD₄ ⁺/CD₈ ⁺ and the expression level of mIL-2R induced and not induced by PHA were 1.5±0.3, (4.1±1.2)% and (23.8±5.2)%, respectively. There was no significant difference between the HIE group and the normal controls (P>0.05). Conclusions  Peripheral blood mononuclear cells of newborns are immature and undifferentiated with a very low expression level of surface markers. The changes of cell immunity involve in the pathogenesis of HIE. The disorder of cellular immune function exists in newborns with HIE. Cell immunity and immune regulative response in newborns are gradually improved or mature during the period of growing, facilitating the recovery from brain injury caused by HIE.