PHYTOSTEROLAEMIA - DIAGNOSIS, CHARACTERIZATION AND THERAPEUTIC APPROACHES

Phytosterolaemia (sitosterolaemia) is a very rare inherited sterol sto rage disease characterized by tendon and tuberous xanthomas and by a s trong predisposition to premature coronary atherosclerosis. In additio n to increased or normal serum cholesterol, patients are found to have markedly elevated concentrations of the phytosterols sitosterol and c ampesterol. These sterols accumulate in all tissues, except the brain. Increased intestinal absorption of plant sterols, impaired biliary ex cretion, and decreased cholesterol synthesis are suggested as causes f or this disease, However, the primary defect has not yet been identifi ed, As well as dietary restrictions of cholesterol and plant sterols, therapeutic approaches based on interruption of the enterohepatic circ ulation of bile acids by administration of bile acid-binding resins or ileal bypass surgery have been recommended as therapeutic approaches to reduce ail serum sterols, Administration of sitostanol, a nonabsorb able saturated plant sterol, showed a significant reduction of serum p lant sterols and cholesterol in two patients with phytosterolaemia, pr esumably by competitive inhibition of sterol absorption.