Clinical implication of the changes of cAMP, TXA₂ and PGI₂ in CSF of asphyxiated newborns

Abstract

To evaluate the changes of 3′, 5′-cyclic adenosine monophosphate (cAMP), thromboxane A₂(TXA₂) and prostacyclin (PGI₂) in cerebrospinal fluid (CSF) in the asphyxiated newborn and explore their roles in hypoxic-ischamic brain damage (HIBD). Thirty-six full term newborns were divided into 3 groups, including 12 with moderate-severe hypoxic-ischaemic encephalopathy (HIE), 13 with mild HIE, 11 without HIE (control group). The levels of cAMP, TXB₂ (TXA₂ metabolite) and 6-keto-PGF_1α (PGI₂ metabolite) in CSF and plasma were measured 36–72 h after birth by RIA, and the concentrations were expressed as nM/L (cAMP), ng/L(TXB₂ and 6-keto-PGF_1α). The infants were followed-up at 6 and 12 month of age and Mental Development Index (MDI) and Psychomotor Development Index (PDI) were measured using Bayley Scales of Infant Development (BSID). The CSF cAMP level in moderate-severe HIE group was 8.60±2.40, significantly lower than that of the mild HIE group (14.83±2.84) and the control group (24.43±2.39) (for bothP<0.01). The levels of TXB₂ and 6-keto-PGF_1α in CFS in the moderate-severe HIE group (206.06±29.74, 168.47±23.02, respectively) were significantly higher than in the mild HIE group (83.37±28.57, 131.42±16.57, respectively,P<0.01) and the control group (41.77±21.58, 86.23±13.05, respectively,P<0.01). The level changes of cAMP, TXB₂ and 6-keto-PGF_1α in plasma in all groups were similar to those in CSF, but no significant difference was found between mild HIE group and the control group (P>0.05). The follow-up results showed that MDI and PDI of the moderate-severe HIE group were the lowest (84.79±13.34, 83.50±13.28, respectively), followed by mild HIE group (102.19±7.02, 99.94±9.08, respectively), with the control group being the highest (116.63±12.08, 116.69±10.87, respectively). Univariate analysis showed some significant difference (the moderate-severe HIE group vs. the mild HIE group or the control group,P<0.01; the mild HIE group vs. the control groupP<0.05). The results suggested that the concentration of cAMP, TXA₂ and T/K ratio in CSF after neonatal asphyxia might be sensitive markers in evaluating the severity of brain damage in early stage and predicting the future outcome.

Keywords

neonate infant / asphyxia / 3′, 5′-cyclic adenosine monophosphate / prostacyclins / thromboxane A₂ / cerebrospinal fluid

References

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