A high index of suspicion is important in individuals with early-onset emphysema.
Individuals with low plasma AAT levels should undergo genetic phenotyping to better characterize disease quality.
Pulmonary function testing (PFT) and CT are also useful in detecting and diagnosing AAT-deficiency lung disease. PFT can also help differentiate AAT-deficiency lung disease from asthma.
Discusses the clinical features that should prompt a consideration of COPD and the investigations that are useful in diagnosis. The guidelines note that AAT deficiency is the best-documented genetic risk factor and one that serves as a model for how other genetic risk factors may contribute to the development of COPD.
Targeted testing for AAT deficiency should be considered in patients with COPD who are either diagnosed before the age of 65 or who report a smoking history less than 20 pack-years.
Targeted testing should not be performed in those diagnosed with asthma or bronchiectasis.
AAT augmentation therapy is indicated for individuals with AAT deficiency-associated emphysema if they exhibit moderate airflow obstruction on pulmonary function testing (FEV1 35% to 60% of predicted). No firm recommendation is provided for AAT deficiency manifesting as mild or severe airflow obstruction.
Any individual with COPD as a result of AAT deficiency should be treated according to the standards of care for that condition - namely bronchodilators, inhaled corticosteroids, oxygen, systemic corticosteroids, and antibiotics.
Liver transplantation is indicated for those with end-stage liver disease.
Patients diagnosed with COPD at a young age or who have a strong family history should be investigated for AAT deficiency in order to provide screening for family members.
AAT augmentation therapy may be considered for young patients with severe hereditary AAT deficiency and established emphysema.
Augmentation may be considered in nonsmokers or ex-smokers with COPD and FEV1 25% to 80% predicted, who have AAT levels <11micromol/L and are otherwise optimized (pharmacologically and nonpharmacologically).