Reduction in lymphoctye β-adreneraic receptor density in infants and children with heart failure secondary to congenital heart disease

Abstract

To identify changes in catecholamine levels and β-adrenergic receptor density in children with varying degrees of congestive heart failure, we measured plasma norepinephrine (NE), epinephrine, and β-adrenerSic receptor levels in 91 noncyanotic patients using igh-performance liquid chromatography and a radioligand binding assay. Plasma NE levels in 41 patients with heart failure (694 ± 236 pg/ml) were significantly higher than those in 50 patients without it (274 ± 68 pg/ml, p < 0.001). In addition, β-adrenergic receptor density was significantly lower in patients with heart failure (0.81 ± 0.48 fmol/10 6 cells) than in those without it (2.43 ± 1.09 fmol/10 6 cells, p < 0.001), but epinephrine levels were not significantly different between the 2 groups. The receptor reduction in heart failure correlated well with elevated plasma NE levels (r = −0.60, p < 0.001). The degree of left to right shunt flow and pulmonary systolic pressure correlated directly with plasma NE levels and inversely with β-adrenergic receptor density. From the best compromise between sensitivity and specificity, the optimal cutoff point for heart failure was >390 ng/ml for NE and <1.30 fmol/10 6 cells for β-adrenergic receptor density, respectively. A follow-up study in 15 of 30 patients with heart failure after surgery showed a significant decrease in plasma NE and an increase in β-adrenergic receptor density. Changes in plasma NE levels and β-adrenergic receptor density occur concurrently with clinical symptoms of heart failure and may be used as indexes for assessing the presence and severity of heart failure in infants and children.