Biochemical timing of peri-intraventricular hemorrhage assessed by perinatal CPK-BB isoenzyme measurements

Perfusion monitoring and intraventricular hemorrhage in preterm infants

Cardiovascular instability in preterm infants during the early postnatal period correlates with the development of intraventricular hemorrhage (IVH). Due to the correlation between hypotension and fluctuation of blood pressure, treatment was targeted specifically at hypotension to prevent IVH, but this was not successful. Recently, several novel perfusion markers have been found to be correlated with the development of IVH, and they are of current interest in cardiovascular management. In this review, the correlation between IVH and conventional, as well as novel, perfusion markers is examined.

A Systematic Review and Meta-analysis of the Timing of Early Intraventricular Hemorrhage in Preterm Neonates: Clinical and Research Implications

A considerable number of intraventricular hemorrhages (IVH) occur within the first hours of life (HOL). Temporality between IVH and its antecedents as well as a consistent definition of "early IVH" is lacking in a large and growing body of literature. We performed a systematic review of prospective studies that reported onset of IVH in preterm neonates within the first HOL and afterwards. The English literature was searched using three databases up to March 2013. Four timing periods of IVH can be compared in 16 identified studies: 0-6; 7-12; 13-24; after 24 HOL. The 0-6 and after 24 HOL were the major modes of IVH timing. Pooled IVH proportions were estimated through a meta-analysis of studies that were conducted after antenatal steroid and surfactant era. In neonates weighing ≤1500 g at birth: 48% of IVH (95% CI: 42-58%, 5 studies, 279 IVH cases) occurred during 0-6 HOL and 38% (95% CI: 19-57%, 4 studies, 241 IVH cases) after 24 HOL. The 0-6 HOL is the shortest, most vulnerable period for IVH, thus, an early IVH is an IVH occurs in it. Such early IVH had prognostic, etiological/preventive and medicolegal implications. Accordingly, preterm neonates at risk of IVH should have their first routine screening head ultrasound at about 6 HOL. Future research exploring the antecedents of IVH should guaranty the temporality between these antecedents and IVH. Additional research will be required to determine whether the long term neurological outcomes of early and late IVH are the same.

Biomarkers of brain injury in the premature infant

The term “encephalopathy of prematurity” encompasses not only the acute brain injury [such as intraventricular hemorrhage (IVH)] but also complex disturbance on the infant’s subsequent brain development. In premature infants, the most frequent recognized source of brain injury is IVH and periventricular leukomalacia (PVL). Furthermore 20–25% infants with birth weigh less than 1,500 g will have IVH and that proportion increases to 45% if the birth weight is less than 500–750 g. In addition, nearly 60% of very low birth weight newborns will have hypoxic-ischemic injury. Therefore permanent lifetime neurodevelopmental disabilities are frequent in premature infants. Innovative approach to prevent or decrease brain injury in preterm infants requires discovery of biomarkers able to discriminate infants at risk for injury, monitor the progression of the injury, and assess efficacy of neuroprotective clinical trials. In this article, we will review biomarkers studied in premature infants with IVH, Post-hemorrhagic ventricular dilation (PHVD), and PVL including: S100b, Activin A, erythropoietin, chemokine CCL 18, GFAP, and NFL will also be examined. Some of the most promising biomarkers for IVH are S100β and Activin. The concentrations of TGF-β1, MMP-9, and PAI-1 in cerebrospinal fluid could be used to discriminate patients that will require shunt after PHVD. Neonatal brain injury is frequent in premature infants admitted to the neonatal intensive care and we hope to contribute to the awareness and interest in clinical validation of established as well as novel neonatal brain injury biomarkers.

Cerebral and renal artery blood flow velocity before and after birth

OBJECTIVE

To document perinatal changes in cerebral and renal artery haemodynamics in premature growth-retarded and normal term infants.

DESIGN

Longitudinal study of individual infants. Doppler ultrasound measurements of blood flow velocity (BFV) in the middle cerebral and renal arteries were obtained before delivery, soon after delivery and during the first week of postnatal life.

SETTING

Teaching hospital obstetric and neonatal units.

SUBJECTS

13 severely growth retarded infants born at 28-36 weeks gestation, and eight normally grown infants born at term.

RESULTS

In both groups, BFV in the cerebral artery was significantly lower in the first few hours after birth than in fetal life, but subsequently increased to reach pre-delivery values by the end of the first week. In contrast, BFV in the renal artery during the first postnatal day was not significantly different from fetal values, but it also increased during the subsequent week. In six of the preterm growth-retarded infants, fetal blood gases were measured in samples obtained by cordocentesis, and in these cases an increase in blood oxygen content at birth was documented.

CONCLUSIONS

Cerebral artery BFV falls at birth and is relatively low during the time that premature infants are at the greatest risk of developing periventricular haemorrhage.

Serum macro creatine kinase type 2 in asphyxiated newborn infants

The presence of macro creatine kinase type 2 (MCK2) activity was noted in the serum of seven out of 32 newborn infants with perinatal asphyxia or birth trauma. MCK2 isoenzyme, when present, represented 15-35% of the total creatine kinase (CK) activity. The clinical and biochemical features of the seven MCK2-positive and 25 MCK2-negative newborns were compared. The infants with MCK2 activity were all males and clinically appeared to be more severely injured, requiring longer hospitalization. Total CK activity was similar in the two groups and CK-MB and CK-BB isoenzyme fractions were present in a similar proportion of infants in both groups. Two infants in each group had long-term neurological disorders. Although the presence of MCK2 has been noted in adult patients with end-stage metastatic solid tumors, the presence of this isoenzyme has not previously been reported in newborn infants.

Creatine phosphokinase isoenzyme activity in umbilical artery, umbilical vein and capillary blood of newborn infants at term

Serum levels of creatine phosphokinase isoenzyme pattern (CPK MM, MB, BB) were measured in cord blood and capillary blood samples of 20 healthy term infants. Total CPK activity was high but similar in all samples, the main source being derived from the CPK-MM fraction. The CPK-MB fraction was absent in cord blood. Moreover, CPK-BB activity was significantly higher in capillary blood than in cord blood. These results suggest specific organ involvement in the production of CPK fractions.