phytosterols and Anemia--Hemolytic

Sitosterolemia is a rare autosomal recessively inherited disease caused by mutations affecting ABCG5 or ABCG8, which are located on human chromosome band 2p21. Around 100 cases have been reported in the literature. Sitosterolemic patients typically exhibit a 30-fold to 100-fold increase in plasma concentrations of plant sterols. The clinical manifestations include xanthomas, premature atherosclerosis, hemolytic anemia, and macrothrombocytopenia. It is noteworthy that abnormal hematological parameters may be the only clinical feature of sitosterolemic patients, suggesting that sitosterolemia may be more frequent than previously thought. Severe accumulation of plant sterols in mouse models of sitosterolemia induced complex cardiac lesions, anemia, and macrothrombocytopenia, disrupted adrenal and liver cholesterol homeostasis, and caused infertility and hypertriglyceridemia. It remains unclear whether all disease traits are present in sitosterolemic patients. The drug ezetimibe appears to be effective in reducing plasma plant sterol levels, promotes xanthoma regression, and improves the cardiovascular and hematological signs in sitosterolemic patients.

Topics: Anemia, Hemolytic; Animals; Anticholesteremic Agents; Atherosclerosis; Azetidines; Ezetimibe; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Mice; Phytosterols; Thrombocytopenia; Xanthomatosis

Topics: Anemia, Hemolytic; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Thrombocytopenia

An adult Chinese man presented with tendinous and tuberous xanthomatosis and severe atheromatous changes in the coronary arteries. In addition, he had chronic hemolytic anemia, with spherostomatocytic erythrocytes. Cerebrotendinous xanthomatosis was diagnosed on the basis of increased cholestanol levels in his plasma, red cells and xanthoma, changes in bile acid composition due to the defective synthesis of chenodeoxycholic acid. Coexisting beta-sitosterolemia was confirmed by the finding of large amounts of the plant sterols such as beta-sitosterol and campesterol. This is the first report of these two rare lipid storage disorders in the same patient.

Topics: Adult; Anemia, Hemolytic; Chenodeoxycholic Acid; Cholestanols; Cholesterol; Coronary Disease; Humans; Lipidoses; Phytosterols; Sitosterols; Spherocytes; Xanthomatosis