Elimination of Hemoglobin and Lactate Dehydrogenase from Plasma in Normals and Patients with Intravascular Hemolysis

Abstract

After intravenous injection of 10 ml hemolysate, hemoglobin was eliminated exponentially with a mean T/2 of 26 minutes in 3 patients with ahaptoglobinemia due to intravasclar hemolysis. In 3 subjects with normal haptoglobin values, the clearance of the hemoglobin-haptoglobin complex also seemed to follow first order kinetics, the T/2 being 149 minutes. Only about 50 per cent of the lactate dehydrogenase injected was eliminated from plasma in 24 hours. The rapid elimination of free Hb explains why the plasma Hb concentration is a poor indicator of the degree of intravascular hemolysis, while the slow LDH clearance makes LDH determinations more convenient for this purpose.