What is AATD, and why is it a concern for patients with COPD?
Alpha-1 Antitrypsin Deficiency (AATD) is a genetic condition which predisposes to COPD. All of us carry 2 copies or alleles of the gene for AAT – the normal one is termed M, and the most common abnormal ones are S and Z.
The Z allele leads to lower levels than S. In general, having only one abnormal gene (combinations of M and either S or Z) is not a risk factor for COPD, unless patients smoke. People with 2 abnormal genes may be at risk of COPD even in the absence of smoking; this is particularly the case for people with 2 copies of the Z gene.
ERS encourages the screening of all COPD patients for AATD. How can this improve patient outcomes?
If AATD is diagnosed, access to specialist care can be provided via a limited number of centres in the UK. These centres offer specialist advice on management and prognosis and may have the facilities to help with family screening, which is recommended for all first-degree relatives of people who have 2 abnormal alleles for AATD.
There are now several observational research studies offering more detailed follow-up than NHS care, as well as drug trials of specific treatments for AATD available in specialist centres. Whilst such research cannot guarantee benefit for patients these may be of interest to some people, and it may provide reassurance to know that progress is being sought for the condition through active research.
Where can respiratory specialists find resources to help support the execution of consistent screening across COPD patients?
NHS hospitals all have access to the testing of AAT levels, and if these are low, this will trigger testing to identify M, S and Z alleles either by looking at the protein on a gel or by PCR for the genes.
The test can also be sent from primary care, in the same way as any other blood test. The ERS has a statement from 2017 which explains more about AATD and when to test.