Long-Term Follow-up of Premature Infants Treated With Prophylactic, Intratracheal Recombinant Human CuZn Superoxide Dismutase

Abstract

OBJECTIVE:To examine the long-term effects of treatment with recombinant human CuZn superoxide dismutase (rhSOD) in infants enrolled previously in two placebo-controlled trials. STUDY DESIGN:Records for 46 (88%) infants were examined, with 19 infants having received either single or multiple intratracheal (i.t.) doses of placebo, 12 having received a single i.t. dose of rhSOD, and 15 having received multiple i.t. doses of rhSOD. Mean age at follow-up was 28 months corrected age. Records were examined for neurologic dysfunction, developmental delay, and any significant medical disorders. RESULTS:Four placebo infants (21%) had evidence of neurodevelopmental abnormalities and four infants developed asthma. Four single-dose rhSOD infants (33%) had neurodevelopmental abnormalities and two infants developed asthma. One multiple-dose rhSOD infant had evidence of neurodevelopmental abnormalities and one developed asthma. No other differences were found between the placebo and rhSOD groups. CONCLUSION:Preliminary data suggest that rhSOD is safe and not associated with any long-term adverse effects. Further results will depend on the results of multicenter trials of rhSOD in preterm infants. Journal of Perinatology 2000; 4:213-216.Oxygen free radical injury has been implicated in the pathogenesis of a wide variety of conditions that may affect newborns. This is not surprising, because newborns (especially premature infants) are uniquely susceptible to free radical injury. Premature infants are exposed to supraphysiological oxygen concentrations compared with the intrauterine environment and may experience reperfusion injury after periods of hypoxia or ischemia. In addition, newborns may have inadequate defenses against free radical injury. Free radicals can cause damage to both the pulmonary and central nervous systems, resulting in significant long-term sequelae. Bronchopulmonary dysplasia (BPD) can develop in up to 40% of premature neonates with birth weights of Ͻ1500 gm who are treated with oxygen and mechanical ventilation. 1 The development of BPD is associated with increased mortality and morbidity, such as repeated hospitalizations and neurodevelopmental handicaps. 2 Intraventricular hemorrhage (IVH) and/or periventricular leukomalacia can also develop in 20% to 40% of very low birth weight infants, resulting in long-term neurodevelopmental deficits such as cerebral palsy. 3 Treatment directed at preventing free radical injury may decrease the incidence and severity of these conditions and improve long-term outcome.Superoxide dismutases (SODs) are ubiquitous antioxidant enzymes that have been shown to prevent free radical injury due to hyperoxia and reperfusion. Several animal studies have demonstrated that SOD treatment mitigated lung injury from prolonged hyperoxia and mechanical ventilation. 4 -6 SOD administration has also been found to decrease the incidence of IVH and brain injury in animal studies. 7 rhSOD is a human recombinant CuZn SOD that has been given to premature infants with respiratory distress synd...

Long-Term Tidal Liquid Ventilation in Premature Lambs: Physiologic, Biochemical and Histological Correlates

“…high-frequency ventilation [22], patient-triggered ventilation, pressure-support/volume guarantee, assist-control/volume guarantee, synchronized intermittent mandatory ventilation and assist-control ventilation [23], proportional assisted ventilation [24], surfactant administration [25], delivery of oxygen radical scavengers, i.e. superoxide dismutase [26,27], protease inhibitors, i.e. alpha-1-proteinase [28,29], as well as current investigation of agents with anti-inflammatory potential, i.e.…”

Bronchopulmonary Dysplasia

“…Although there was no difference in the primary outcome of death and/or BPD, the administration of rhSOD was associated with less severe intraventricular hemorrhage and periventricular leukomalacia. At 6 mo and at 12 mo of corrected age, infants treated with rhSOD had a reduced need for respiratory medications as compared with infants receiving placebo (45). Antioxidant administration for the prevention and treatment of BPD will need to be further evaluated.…”

Antioxidants as Therapy in the Newborn: Some Words of Caution

“…The outcomes of other antioxidant interventions in ongoing trials, such as intratracheal recombinant human SOD (82), are yet to be determined.…”