Further studies on plasma proteins, lipids, and dye- and drug-binding in a child with analbuminemia

Abstract

A previously reported patient with analbuminemia was re-investigated after 4 1/2 years, at age 6. The serum albumin concentration was 150 mg/L by radioimmunoassay. Most of the observed increase in total plasma protein over the 4 1/2 years was attributable to gamma-globulin. Concentrations of total and high-density lipoprotein cholesterol were increased; the esterified:free ratio and the lecithin-cholesterol acyltransferase activity were both normal. Albumin is apparently not essential for binding of lysolecithin generated by the acyltransferase-catalyzed reaction. The binding of bromphenol blue suggested that analbuminemic serum has about 25% of normal binding capacity for bilirubin (more than expected in a patient with analbuminemia), which may explain why newborns with this disorder do not develop kernicterus. Binding by the patient's plasma of diazepam (1020 mg/L) and warfarin (1040 mg/L), which bind primarily to albumin, as well as of propranolol (1.05 g/L), which binds primarily to α1-acid glycoprotein, was also studied. The proportions of free diazepam (14.4%) and warfarin (4.8%) were about 10-fold normal. In contrast, the proportion of propranolol in the free form was decreased (4.5%). Evidently, other plasma proteins are partly compensating for the deficiency of albumin.