Abstract
Clinical and experimental studies on hereditary spherocytosis (HS) and high red cell membrane phosphatidylcholine hemolytic anemia (HPCHA) were performed in relation to lipid metabolism in plasma and in red cells of these patients.
In HS, red cell (RBC) membrane lipids (free cholesterol (FC) and phospholipids (PL) such as phosphatidylethanolamine, phosphatidylcholine (PC), sphingomyelin (SM) and lysophosphatidylcholine (LPC)) were markedly decreased in unsplenectomized HS. Plasma lipids (total cholesterol, FC, HDL-cholesterol, PL) were also decreased in these patients. After splenectomy, substantial normalization of plasma and RBC lipids were observed. Concerning lipid kinetics, the extents of 14C-PC synthesis in RBC from 14C-LPC in medium and of 14C-PC exchange between RBC and the medium were almost identical to those in normal control in the in vitro incubation conditions. These observations indicate that the decreased RBC lipids may be induced by the shortage of lipid materials in plasma in the presence of the spleen.
In unsplenectomized HPCHA, plasma lipids were also decreased same as in HS. In contrast, membrane lipids (FC and PC) were markedly increased. Even after splenectomy, increased PC contents were rather enhanced in their membranes concomitant to developing of hemolytic anemia, although plasma lipids were almost normalized. Thus RBC membrane lipids in HPCHA appeared not to be affected by plasma lipids.
In experimental studies on HPCHA, 14C-PC synthesis from 14C-LPC and 14C-PC uptake in these RBC were increased, in spite that large amounts of PC were already accumulated in these RBC. Thus, increased uptake of LPC and PC from the enviroment appears to be the major cause of the accumulation of PC in the RBC of HPCHA patients.
In addition, it should be noted that splenectomy in HPCHA showed no beneficial effect (rather worsened clinically), and therefore the procedure should be avoided in the HPCHA.
