Alpha 1 Antitrypsin (A1AT) Quantitative Blood Biomarker Testing
It measures your blood level of alpha-1 antitrypsin to assess inherited deficiency risk and inflammation effects, with easy ordering and Quest-based labs via Vitals Vault.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
Alpha-1 antitrypsin (A1AT) is a protective protein your liver releases into your bloodstream. One of its main jobs is to help shield your lungs from damage during normal inflammation.
A quantitative A1AT test measures how much of this protein is circulating in your blood. It is often used when you have early or unexplained lung disease, certain liver findings, or a family history that raises the question of alpha-1 antitrypsin deficiency.
Because A1AT rises during infections and other inflammatory states, a “normal” number does not always rule out deficiency. Your result is most useful when it is interpreted alongside your symptoms, other labs, and sometimes follow-up testing that looks at the type (phenotype/genotype) of A1AT you make.
Do I need a Alpha 1 Antitrypsin Quantitative test?
You might consider an A1AT quantitative test if you have lung symptoms that seem out of proportion for your age or smoking history, such as persistent shortness of breath, wheezing, chronic cough, or a diagnosis of emphysema or COPD at a younger age. Clinicians also use it when asthma treatment is not working as expected, because A1AT deficiency can mimic or worsen obstructive lung disease.
This test is also commonly ordered when liver issues are unexplained. That can include elevated liver enzymes, fatty liver that does not fit your risk profile, jaundice, or a history of hepatitis-like symptoms without a clear cause. In children, A1AT deficiency can present with prolonged jaundice or abnormal liver tests.
Family history matters. If a close relative has alpha-1 antitrypsin deficiency, early emphysema, bronchiectasis, or unexplained cirrhosis, measuring your A1AT level can be a practical first step.
Testing helps you and your clinician decide whether you need confirmatory testing (phenotype or genotype), additional liver and lung evaluation, or a plan to monitor over time. It is not a stand-alone diagnosis by itself.
This is a quantitative blood test performed in a CLIA-certified laboratory; results should be interpreted with your clinical history and may require confirmatory phenotype/genotype testing for diagnosis.
Lab testing
Order an Alpha 1 Antitrypsin Quantitative test
Schedule online, results typically within about a week
Clear reporting and optional clinician context
HSA/FSA eligible where applicable
Get this test with Vitals Vault
Vitals Vault lets you order an Alpha 1 Antitrypsin Quantitative test without needing to start with an in-person visit. After you place your order, you complete the blood draw at a participating lab site, and your results are delivered to you in a clear, shareable format.
If your number is low, unexpectedly high, or confusing in context, PocketMD can help you turn the lab value into next-step questions for your clinician, such as whether you should add A1AT phenotype/genotype testing, check inflammatory markers, or review liver and lung labs together.
This test can also be useful for retesting when timing matters. Because A1AT can rise during illness, repeating the test when you are well (or pairing it with an inflammation marker) can make the result easier to interpret.
You stay in control of what you order and when you recheck, while still keeping the focus on clinician-directed care when follow-up is needed.
- Order online and complete your draw at a participating lab location
- PocketMD helps you interpret results and plan sensible follow-up questions
- Easy reordering when you need to confirm or trend a result
Key benefits of Alpha 1 Antitrypsin Quantitative testing
- Helps screen for alpha-1 antitrypsin deficiency when lung symptoms or early emphysema raise suspicion.
- Adds context to unexplained liver enzyme elevations by checking a liver-made protective protein.
- Supports family-history risk assessment so you can decide if confirmatory phenotype/genotype testing is worth it.
- Helps explain why obstructive lung disease may be progressing faster than expected.
- Guides smarter retesting, since A1AT can look “normal” during inflammation and illness.
- Pairs well with liver and inflammation labs to separate inherited deficiency from an acute-phase response.
- Gives you a concrete data point to review in PocketMD and bring to your clinician for next-step planning.
What is Alpha 1 Antitrypsin (A1AT)?
Alpha-1 antitrypsin (A1AT) is a protein made primarily in your liver and released into your blood. Its best-known role is to protect lung tissue by inhibiting enzymes (especially neutrophil elastase) that your immune system uses during inflammation. When A1AT levels are too low—or when the A1AT protein is abnormal—those enzymes can damage the delicate air sacs in your lungs over time.
A1AT is also an “acute-phase reactant,” which means your body can increase production during inflammation, infection, injury, or other stress. That protective rise is normal, but it can complicate interpretation if you are trying to detect an inherited deficiency.
Alpha-1 antitrypsin deficiency is usually inherited. Some genetic variants lead to low circulating A1AT, while others cause the protein to misfold and accumulate in the liver, which can contribute to liver injury. A quantitative test measures the amount of A1AT in your blood, but it does not tell you which variant you have.
If your level is low (or borderline) and the clinical suspicion is high, clinicians often follow up with A1AT phenotype testing (which looks at the protein pattern) or genotype testing (which looks at the gene variants).
Why a “quantitative” level is only part of the story
A normal A1AT level can occur even if you carry a deficiency variant, especially if the test is done during an inflammatory flare when A1AT is temporarily elevated. On the other hand, a low level strongly raises suspicion, but confirmatory testing is typically needed to define the type of deficiency and the associated risk.
How this connects to lungs and liver
In the lungs, low functional A1AT can increase the risk of early emphysema, chronic bronchitis-like symptoms, and sometimes bronchiectasis. In the liver, certain variants can lead to protein buildup inside liver cells, which may show up as abnormal liver enzymes, cholestasis, fibrosis, or cirrhosis in some people.
What do my Alpha 1 Antitrypsin Quantitative results mean?
Low Alpha 1 Antitrypsin levels
A low A1AT level can suggest alpha-1 antitrypsin deficiency, especially if you have early-onset emphysema, persistent obstructive lung symptoms, or unexplained liver findings. The lower the value, the more likely a clinically meaningful deficiency is present, but the exact cutoffs vary by lab and method. Your clinician may recommend confirmatory phenotype or genotype testing and may also review liver enzymes and lung function testing to understand your risk and current organ health.
In-range (typical) Alpha 1 Antitrypsin levels
An in-range result often means you have an adequate circulating amount of A1AT at the time of testing. However, because A1AT increases during inflammation, an in-range value does not always rule out a deficiency variant—particularly if you were sick, recently injured, or had active inflammation. If suspicion remains high due to symptoms or family history, your clinician may still consider phenotype/genotype testing or repeating the level when you are well.
High Alpha 1 Antitrypsin levels
A high A1AT level is most commonly a sign that your body is responding to inflammation, infection, tissue injury, or other stress. It is usually not harmful by itself, but it can mask an underlying deficiency by pushing the number into the reference range. If your result is high and the test was ordered to evaluate deficiency risk, it is reasonable to discuss whether an inflammation marker (such as CRP) or repeat testing at a stable baseline would clarify the picture.
Factors that influence Alpha 1 Antitrypsin
A1AT rises with acute illness, chronic inflammatory conditions, and sometimes with physiologic stress, which can make a single measurement hard to interpret. Pregnancy, estrogen-containing medications, and some inflammatory liver conditions can also increase levels. Severe liver dysfunction can lower production, while inherited variants can lower the level or reduce functional activity even if the number is not dramatically low. Timing your test when you feel well and reviewing it alongside liver enzymes and inflammation markers can make the result more actionable.
What’s included
- Alpha-1-Antitrypsin Qn
Frequently Asked Questions
What does an alpha-1 antitrypsin quantitative test measure?
It measures the concentration of alpha-1 antitrypsin (A1AT) in your blood. A1AT is a liver-made protein that helps protect your lungs from enzyme-related damage during inflammation and can be involved in certain inherited liver conditions.
Can you have alpha-1 antitrypsin deficiency with a normal A1AT level?
Yes. Because A1AT is an acute-phase reactant, your level can rise during infection or inflammation and appear normal even if you carry a deficiency variant. If your symptoms or family history strongly suggest deficiency, confirmatory phenotype or genotype testing may still be appropriate.
Do I need to fast for an A1AT blood test?
Fasting is not usually required for an A1AT quantitative test. If your clinician orders it alongside other labs that do require fasting (such as lipids), follow the instructions for the full set of tests.
What is the difference between A1AT level and A1AT phenotype or genotype testing?
The quantitative test tells you how much A1AT is in your blood. Phenotype testing looks at the protein pattern to infer common variants, and genotype testing checks the gene variants directly. Level testing is often a first step, while phenotype/genotype helps confirm the diagnosis and clarify inherited risk.
When should I retest alpha-1 antitrypsin?
Retesting is often considered if your first test was done during an illness or inflammatory flare, or if the result was borderline and clinical suspicion remains. Many people repeat when they are back to a stable baseline, or they add an inflammation marker so the A1AT value can be interpreted in context.
What conditions can cause high alpha-1 antitrypsin?
High A1AT is most often linked to inflammation or infection, because your body increases production as part of the acute-phase response. Some chronic inflammatory diseases, physiologic stress, pregnancy, and estrogen-containing medications can also raise levels.
What other tests are commonly checked with A1AT for liver or lung evaluation?
For liver context, clinicians often review AST, ALT, alkaline phosphatase, bilirubin, albumin, and INR depending on the situation. For lung context, spirometry (pulmonary function tests) and imaging may be considered. If deficiency is suspected, A1AT phenotype or genotype testing is a common next step.