Etretin

Synthetic retinoid used in dermatology

Engineered Monoclonal Antibodies

Diagram of engineered monoclonal antibodies

Engineered monoclonal antibodies are a class of biological therapies that are designed to target specific antigens on the surface of cells. These antibodies are produced using recombinant DNA technologies and are used in the treatment of various diseases, including cancer, autoimmune disorders, and infectious diseases.

Structure and Function

Monoclonal antibodies are composed of two identical heavy chains and two identical light chains, forming a Y-shaped molecule. The tips of the "Y" contain the antigen-binding sites, which are highly specific to the target antigen. This specificity allows monoclonal antibodies to bind to their target with high affinity, blocking or modulating the function of the antigen.

Types of Engineered Monoclonal Antibodies

There are several types of engineered monoclonal antibodies, each designed for specific therapeutic purposes:

• Chimeric antibodies: These antibodies are composed of murine (mouse) variable regions and human constant regions. They are less immunogenic than fully murine antibodies.

• Humanized antibodies: These antibodies are mostly human, with only the antigen-binding sites derived from murine sources. This reduces the risk of immune reactions.

• Fully human antibodies: These are entirely human in origin, produced using transgenic mice or phage display technologies.

• Bispecific antibodies: These antibodies are engineered to bind two different antigens simultaneously, offering unique therapeutic mechanisms.

Applications in Medicine

Engineered monoclonal antibodies have revolutionized the treatment of many diseases:

• Cancer therapy: Monoclonal antibodies can target specific tumor antigens, leading to direct tumor cell killing or recruitment of immune cells to attack the tumor.

• Autoimmune diseases: By targeting specific components of the immune system, monoclonal antibodies can reduce inflammation and tissue damage in diseases such as rheumatoid arthritis and multiple sclerosis.

• Infectious diseases: Monoclonal antibodies can neutralize pathogens or their toxins, providing passive immunity or enhancing the host's immune response.

Production

The production of engineered monoclonal antibodies involves several steps:

1. Antigen identification: The target antigen is identified and characterized. 2. Hybridoma technology: B cells from immunized animals are fused with myeloma cells to create hybridomas that produce the desired antibody. 3. Recombinant DNA technology: Genes encoding the antibody are cloned and expressed in suitable host cells, such as Chinese hamster ovary cells. 4. Purification and formulation: The antibodies are purified and formulated for clinical use.

Challenges and Future Directions

While engineered monoclonal antibodies have shown great promise, there are challenges such as high production costs, potential for immune reactions, and the development of resistance. Ongoing research aims to improve antibody design, reduce immunogenicity, and enhance therapeutic efficacy.

Related Pages

• Monoclonal antibody therapy
• Biopharmaceutical
• Immunotherapy
• Hybridoma technology

Etretin is a synthetic retinoid primarily used in the field of dermatology for the treatment of severe psoriasis and other skin disorders. It is a derivative of vitamin A and functions by modulating the growth and differentiation of epithelial cells.

Medical Uses

Etretin is indicated for the treatment of severe psoriasis, particularly in cases where other treatments have failed. It is also used in the management of other keratinization disorders such as ichthyosis and pityriasis rubra pilaris. The drug is known for its ability to normalize the growth cycle of skin cells, thereby reducing the formation of scales and plaques.

Mechanism of Action

Etretin works by binding to retinoic acid receptors (RARs) in the skin. This binding alters the expression of genes involved in cell differentiation and proliferation. By influencing these genetic pathways, etretin helps to restore normal skin cell turnover and reduce the symptoms of hyperkeratotic conditions.

Side Effects

Common side effects of etretin include dry skin, cheilitis (inflammation of the lips), and xerophthalmia (dry eyes). More severe side effects can include hepatotoxicity, hyperlipidemia, and teratogenicity. Due to its potential for causing birth defects, etretin is contraindicated in pregnancy and requires strict contraceptive measures for women of childbearing age.

Contraindications

Etretin is contraindicated in patients with known hypersensitivity to retinoids, in pregnant women, and in those with severe liver or kidney dysfunction. It should be used with caution in patients with a history of hyperlipidemia or alcoholism.

Pharmacokinetics

Etretin is well-absorbed when taken orally, with peak plasma concentrations occurring within 2-4 hours. It is highly protein-bound and metabolized in the liver. The drug has a long elimination half-life, which can lead to accumulation in the body with prolonged use.

Related Compounds

Etretin is related to other retinoids such as acitretin, isotretinoin, and tretinoin. These compounds share similar mechanisms of action but differ in their specific indications and side effect profiles.

See Also

• Psoriasis
• Retinoid
• Vitamin A
• Acitretin
• Isotretinoin
• Tretinoin

References

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