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

Summary 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. LIU Hanchu, male, born in 1959, Associate Professor