Demographic and clinical characteristics of patients with α-antitrypsin deficiency genotypes PI*ZZ and PI*SZ in the Spanish registry of EARCO.

BACKGROUND

The Spanish registry of α-antitrypsin deficiency (AATD) integrated in the European Alpha-1 Research Collaboration (EARCO) provides information about the characteristics of patients, in particular those with the PI*SZ genotype, which is frequent in Spain.

METHOD

Individuals with severe AATD defined as proteinase inhibitor (PI) genotypes PIZZ, PISZ and other rare deficient variants were included from February 1, 2020, to February 1, 2022. The analysis focused on a comparison of the characteristics of PIZZ and PISZ patients.

RESULTS

409 patients were included (53.8% men) with a mean±sd age of 53.5±15.9 years. Genotypes were PIZZ in 181 (44.7%), PISZ in 163 (40.2%), PISS in 29 (7.2%) and other in 32 (7.9%). 271 (67.4%) had lung disease: 175 chronic obstructive pulmonary disease (43.5%), 163 emphysema (40.5%) and 83 bronchiectasis (20.6%). Patients with the PISZ genotype were younger, more frequently non-index cases and had a lower frequency of respiratory diseases except asthma compared with PIZZ patients. Among patients with respiratory diseases, PISZ individuals were significantly older both at onset of symptoms and at diagnosis; only asthma was more frequent in PISZ than in PIZZ individuals. Twelve PISZ patients (15.4%) received augmentation therapy compared with 94 PIZZ patients (66.2%; p<0.001).

CONCLUSIONS

There is a high prevalence of PISZ in Spain. Patients with the PISZ genotype were older at symptom onset and diagnosis and had less severe lung disease compared with PIZZ patients. The prevalence of asthma was higher in PISZ, and up to 15% of PI*SZ patients received augmentation therapy.