Enzyme Replacement Therapy

Abstract

Enzyme replacement therapy is a therapeutic approach in which the specific enzyme that is absent or inactive in affected individuals is replaced with a functional enzyme molecule derived from biological sources or produced by biotechnology. A large number and variety of enzyme defects have been identified in humans. Over 40 hereditary deficiency diseases were reported. The common feature is that enzyme deficiency leads to the accumulation of undegraded molecules and lysosomal storage, resulting in organ dysfunction. Crude enzyme preparations are often unsuitable for therapeutic uses because of their potential contamination and antigenicity. Advances in gene identification and cloning led to the subsequent production and demonstration of equal efficacy of recombinant human enzyme. The adverse events recorded range from boxed warnings for severe allergic reactions. This chapter summarizes therapeutic enzymes used in clinical practice, with particular reference to those obtained from biological sources and biotechnology processes.