Plasma hypoxanthine: a marker for hypoxic-ischaemic induced periventricular leucomalacia?

Cerebral ischaemia of the immature brain may result in cavitating periventricular leucomalacia (PVL), an important association of cerebral palsy. Hypoxanthine measured by high performance liquid chromatography was used as a marker of peripartum hypoxia and ischaemia in 116 infants at risk of PVL. PVL was detected by ultrasound. The 81 infants who were unaffected had median (range) gestation of 30 weeks (24-32), weight of 1336 g (724-3790), and a plasma hypoxanthine concentration of 7.8 mumol/l (2.4-48.9). The seven infants who had cavitating PVL had a median gestation of 28 weeks (26-30), weight of 1165 g (682-1860), and a hypoxanthine concentration of 31.9 mumol/l (7.1-149). Cavitating PVL was significantly dependent only on hypoxanthine when controlling for the effects of weight and gestation. This suggests that peripartum hypoxia-ischaemia may be one of the aetiological factors in cavitating PVL. Oxidation of hypoxanthine during reperfusion generates free radicals which may contribute to the tissue destruction of PVL. The association of hypoxia-ischaemia with PVL suggests that PVL may be modified by reducing free radical activity.