Replacement Therapy for Inherited Enzyme Deficiency

Ceramidetrihexosidase, which is lacking in patients with Fabry's disease, has been highly purified from human placental tissue. This enzyme was administered intravenously to two patients with Fabry's disease. The patients tolerated the procedure very well. The enzyme was rapidly cleared from the blood and was taken up to a major extent by the liver. In one patient, the level of circulating ceramidetrihexoside decreased from 53 to 22 nmoles per 10 ml of plasma 40 minutes after the enzyme was administered. In the other, who received 2/5 less enzyme, the level of circulating ceramidetrihexoside decreased from 67 to 45 nmoles per 10 ml of plasma. Infusions of normal fresh plasma or leukocytes and platelets suspended in plasma yielded results resembling the effect obtained with purified enzyme. Plasma infusion had no demonstrable effect. (N Engl J Med 289: 9–14, 1973)