SERPINA1 and alpha 1-antitrypsin deficiency: Although the prevalence studies of AATD have estimated that approximately 1/3500 and 1/6000 individuals of European descent may be affected by severe AATD in its homozygous PI*ZZ form [4], and although the guidelines recommend testing AAT levels in target populations, such as individuals with COPD [8,9,10,11], AATD in COPD remains underdiagnosed [5,6,16].