Abstract
Although the measurement of serum haptoglobin (S-Hp) is of great use for evaluation of intravascular hemolysis, it is not applicable in patients with mechanical prosthetic valves because S-Hp is virtually absent. We administered haptoglobin preparation to ten patients with Bjork-Shiley mitral prosthetic valves and ten patients with the same aortic prosthetic valves. Serum haptoglobin levels were measured periodically afterwards. The maximum haptoglobin level (Hp(max)), serum haptoglobin reducing rate ((Hp-δHp)/δt) and expected haptoglobin disappearing time (hr) were obtained from the subsequent samples. The screening studies which were performed at the same time, such as red blood cell, hemoglobin, reticulocyte count, serum lactic dehydrogenase (LDH), ratio of LDH (1) /LDH (2), serum ferritin, serum indirect bilirubin, serum iron and hemoglobin levels were not predictors of difference of the two groups. On the other hand, serum haptoglobin reducing rate and expected haptoglobin disappearing time in-dicated that hemolysis is higher in patients with aortic prosthetic valve than with mitral prosthetic valve. This haptoglobin administration test seems to be useful for evaluation of subclinical intravascular hemolysis.
