Enzyme Replacement Therapy (ERT) is a therapeutic approach used to treat various lysosomal storage disorders and other conditions caused by enzyme deficiencies. The primary goal of ERT is to supplement or replace the deficient enzyme in order to reduce the accumulation of substrates that cause cellular damage.
Key Points on Enzyme Replacement Therapy ERT:
- Indications:
- ERT is primarily used for lysosomal storage disorders such as:
- Gaucher disease
- Fabry disease
- Pompe disease
- Mucopolysaccharidoses (MPS types I, II, VI, and others)
- Mechanism:
- Recombinant enzymes are administered intravenously to deliver the functional enzyme.
- The enzymes are targeted to lysosomes via mannose-6-phosphate receptors on cell surfaces.
- Benefits:
- Alleviates clinical symptoms related to substrate accumulation (e.g., organomegaly, skeletal deformities, and cardiac involvement).
- Improves quality of life and functional outcomes, especially when initiated early.
- Limitations:
- ERT does not effectively cross the blood-brain barrier, limiting efficacy for central nervous system manifestations of some disorders.
- Lifelong treatment is often required.
- Development of antibodies against the enzyme is a potential challenge in some patients.
- Commonly Used Enzymes:
- Imiglucerase for Gaucher disease
- Agalsidase for Fabry disease
- Alglucosidase alfa for Pompe disease
- Laronidase for MPS I
- Adverse Effects of ERT:
- Infusion-related reactions (fever, rash, anaphylaxis).
- Immunogenicity, which may reduce efficacy over time.