Alpha-1 antitrypsin

Alpha-1 antitrypsin

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  Labelled diagram of Alpha-1 antitrypsin

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  Structure of Alpha-1 antitrypsin

Alpha-1 antitrypsin

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  Alpha 1-antitrypsin (labelled)

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  Alpha-1 antitrypsin

Alpha-1 Antitrypsin

Alpha-1 antitrypsin (A1AT) is a protein produced in the liver that plays a crucial role in protecting the lungs from damage caused by enzymes such as neutrophil elastase. It is a member of the serpin (serine protease inhibitor) superfamily and is encoded by the SERPINA1 gene.

Function

Alpha-1 antitrypsin is primarily responsible for inhibiting the activity of neutrophil elastase, an enzyme that can degrade elastin and other components of the extracellular matrix in the lungs. By inhibiting this enzyme, A1AT helps maintain the structural integrity of the lung tissue and prevents excessive inflammation and tissue damage.

Genetics

The SERPINA1 gene, located on chromosome 14, encodes the alpha-1 antitrypsin protein. There are several alleles of this gene, with the most common being the normal M allele. Variants such as the Z and S alleles can lead to reduced levels of functional A1AT, resulting in a condition known as alpha-1 antitrypsin deficiency.

Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency is a genetic disorder that can lead to chronic obstructive pulmonary disease (COPD) and liver disease. Individuals with this deficiency have lower levels of A1AT, which results in unchecked activity of neutrophil elastase and subsequent lung damage. The deficiency is inherited in an autosomal codominant pattern.

Symptoms

Symptoms of alpha-1 antitrypsin deficiency can include shortness of breath, wheezing, chronic cough, and jaundice. The condition can lead to emphysema and cirrhosis of the liver.

Diagnosis

Diagnosis of alpha-1 antitrypsin deficiency is typically made through blood tests that measure the level of A1AT in the blood and genetic testing to identify mutations in the SERPINA1 gene.

Treatment

Treatment options for alpha-1 antitrypsin deficiency include augmentation therapy with purified A1AT, lifestyle changes such as smoking cessation, and management of symptoms with bronchodilators and corticosteroids. In severe cases, lung transplantation or liver transplantation may be considered.

Related Pages

• Chronic obstructive pulmonary disease
• Liver disease
• Genetic disorder
• Serpin

Classification
External resources