The clinical presentation of AATD lung disease varies widely, challenging the stereotype of the young person suffering from emphysema. There's growing recognition of its association with other chronic respiratory phenotypes, such as asthma and bronchiectasis, although their prevalence and characteristics aren't widely acknowledged, and research findings are controversial.
It is plausible that other AAT proteins, aside from Z, may also play a role in inflammation, as evidenced by studies demonstrating a higher prevalence of bronchiectasis in AATD patients with non-PiZZ phenotypes compared to those with normal levels of AAT.
At the moment, studies about the prevalence and characteristics of bronchiectasis in genotypes other than ZZ involving large international cohorts are missing.