Alpha-1-Antitrypsin

Alpha-1-Antitrypsin is a blood test used to measure the level of alpha-1-antitrypsin (AAT) in serum. AAT is a protective protein produced mainly by the liver. It travels through the bloodstream to the lungs, where it helps protect lung tissue from enzymes released during inflammation.

Inherited changes in the SERPINA1 gene can result in reduced AAT levels or the production of an abnormal AAT protein. A significant deficiency may increase the risk of early-onset emphysema, chronic obstructive pulmonary disease, bronchiectasis, and certain liver disorders. The quantitative serum test is commonly used as an initial investigation when AAT deficiency is suspected.

Benefits of the Test

• Measures the concentration of alpha-1-antitrypsin in serum.
• Supports screening for alpha-1-antitrypsin deficiency.
• Helps investigate early or unexplained emphysema.
• Supports evaluation of COPD occurring without typical risk factors.
• Assists in assessing unexplained chronic liver disease.
• May help determine whether phenotype or genetic testing is required.
• Supports testing of individuals with a family history of AAT deficiency.
• Provides useful information for further respiratory and liver evaluation.

Why Doctors Recommend This Test

Doctors may recommend this test for individuals with early-onset emphysema, COPD with limited smoking history, unexplained bronchiectasis, persistent breathing difficulty, wheezing that does not respond as expected to treatment, or a family history of AAT deficiency. It may also be requested for infants, children, or adults with unexplained liver disease, prolonged jaundice, cirrhosis, or abnormal liver-function results.

Preparation Before Test

• No fasting is generally required unless advised for another accompanying test.
• A blood sample is collected and processed to obtain serum.
• Inform your doctor about current infections, inflammation, pregnancy, and recent illness.
• Provide details about smoking, occupational exposure, lung disease, and liver disease.
• Tell your doctor if a family member has confirmed AAT deficiency, emphysema, or unexplained liver disease.
• Share previous AAT, phenotype, genotype, lung-function, or liver-test reports if available.
• Follow all sample-collection instructions provided by the laboratory.

Normal Reporting Time

The reporting time for the Alpha-1-Antitrypsin test depends on sample receipt, analytical schedules, quality review, and whether additional phenotype or genetic investigations are requested. The quantitative serum result is generally completed within several working days. Please confirm the expected turnaround time with Focus Diagnostics during sample collection.

Who Should Take This Test?

This test may be recommended for:

• Individuals with emphysema or COPD developing at a young age.
• Non-smokers or light smokers with unexplained airflow obstruction.
• Patients with unexplained bronchiectasis or chronic breathing problems.
• People with persistent liver-enzyme abnormalities.
• Infants or children with unexplained prolonged jaundice or liver disease.
• Adults with unexplained cirrhosis or chronic liver disease.
• Individuals with a family history of AAT deficiency.
• Relatives of a person with confirmed abnormal AAT phenotype or genotype.

Detailed Information

Alpha-1-antitrypsin is a protease-inhibitor protein made primarily by liver cells. One of its main functions is to control neutrophil elastase, an enzyme released by immune cells during inflammation. Without sufficient functional AAT, elastase can gradually damage the elastic tissue of the lungs.

AAT deficiency is an inherited condition. Each person receives one copy of the SERPINA1 gene from each parent. Different gene variants can affect the amount or function of the AAT protein. The common normal type is known as M, while S and Z are among the variants commonly associated with reduced levels.

Individuals who inherit two severely affected gene variants may have a greater risk of lung and liver complications. However, disease severity varies considerably. Smoking and exposure to dust, fumes, or other lung irritants can greatly increase the risk and accelerate lung damage in people with AAT deficiency.

Lung complications may include emphysema, chronic obstructive pulmonary disease, and bronchiectasis. Symptoms can include shortness of breath, wheezing, chronic cough, reduced exercise tolerance, and recurrent respiratory infections.

Liver disease occurs through a different mechanism. Certain abnormal forms of AAT can accumulate within liver cells instead of being properly released into the bloodstream. This accumulation may contribute to neonatal liver disease, hepatitis, fibrosis, cirrhosis, portal hypertension, and an increased risk of liver cancer in some affected individuals.

A low serum AAT concentration may support possible deficiency, but a quantitative level alone cannot identify the specific inherited variant. Additional phenotype, proteotype, or SERPINA1 genetic testing may be recommended to confirm the diagnosis.

AAT is an acute-phase reactant, which means its concentration can rise during infection, inflammation, pregnancy, or other physiological stress. A result within the reference range during active inflammation may therefore not completely exclude an underlying genetic deficiency.

Low AAT levels can also be influenced by severe liver dysfunction or protein loss. Doctors may interpret the result with inflammatory markers, liver-function tests, lung-function testing, imaging findings, clinical history, and family history.

This serum test is different from faecal alpha-1-antitrypsin testing. Faecal AAT is generally used in the evaluation of protein-losing enteropathy, while serum AAT testing primarily supports assessment of inherited AAT deficiency and related lung or liver disease.

AAT deficiency cannot be diagnosed or excluded solely from symptoms. Confirmatory testing and specialist evaluation may be required when the measured level is low, borderline, or inconsistent with the clinical findings.

At Focus Diagnostics, Alpha-1-Antitrypsin testing is performed using validated laboratory methodologies and established quality-control procedures to provide accurate and clinically meaningful results.