Testing and Diagnosis
AlphaTest® Kit
Request our complimentary AlphaTest® Kit today. It makes testing for AAT deficiency as easy as a finger-stick blood test.
Early diagnosis of AAT deficiency* is important because, with appropriate therapy and lifestyle modifications, the progression of lung disease may be slowed.
*Also known as Alpha-1, alpha-1 antitrypsin deficiency, AATD, A1-PI deficiency, alpha-1 proteinase deficiency, A1AD, or hereditary or genetic emphysema.
Who Should Be Tested
Current recommendations in the ATS/ERS Statement1 support testing of all your patients with:
- Early-onset emphysema (age 45 years or less, regardless of smoking history)
- Family members of known alpha-1 antitrypsin-deficient patients
- Dyspnea and cough occurring in multiple family members in same or different generations
- Emphysema in the absence of a recognized risk factor (smoking, occupational dust exposure, etc.)
- Emphysema with prominent basilar hyperlucency
- Otherwise unexplained liver disease
- All subjects with chronic obstructive pulmonary disease (COPD)
- Bronchiectasis without evident etiology
- Asthma with spirometry that fails to return to normal with therapy
- Necrotizing panniculitis
- Anti-proteinase 3-positive vasculitis (C-ANCA [anti-neutrophil cytoplasmic antibody]-positive vasculitis)
- Family history of any of the following: emphysema, bronchiectasis, liver disease, or panniculitis
ATS/ERS Standards
"It is recommended that all subjects with COPD or asthma characterized by incompletely reversible air flow obstruction should be tested once for AAT deficiency."1
Testing for AAT Deficiency
Testing for AAT deficiency begins with a simple blood test – an immunoassay – to determine the concentration of AAT protein in plasma or serum.
Blood tests will reveal three types of patients:
Level in milligrams per deciliter (mg/dL)
Level in micromolar units (µM)
Normal
≥150 mg/dL
≥20 µM
Borderline Normal
90-140 mg/dL
12-19 µM
Deficient
<80 mg/dL
<11 µM
Patients who are deficient or borderline should undergo a second blood test – phenotyping – to confirm the genetic abnormality that causes AAT deficiency.1
Phenotyping for AAT deficiency is complicated, with more than 90 different gene mutations (alleles) identified. The most common alleles are M(normal), and S, Z, and null (deficient). 1 The chart below shows how to evaluate the results of phenotyping.
(Measured by Radial Immunodiffusion)
Normal Range
Deficient Range
Units: mg/dL
150 – 350
<80*
Units: µM
20 – 48
<11
*Or less than 50 mg/dL if measured by laboratories using nephelometry instead of radial immunodiffusion
- American Thoracic Society /European Respiratory Society Statement: Standards for the diagnosis and management of individuals with alpha-1 antitrypsin deficiency. Am J Respir Crit Care Med. 2003; 168:818-900.
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