Researchers suggest that alpha-1 antitrypsin deficiency (AATD) diagnoses would increase if patients with chronic obstructive pulmonary disease (COPD) and asthma were included in screening programs, as published in Pulmonology.

They tested the clinical and genetic profiles of 1493 patients in pulmonary outpatient and 465 newborns in a single center in Spain, finding a prevalence of AATD alleles of 30.5%.

“The most common deficient alleles in populations of European ancestry are PI*S and PI*Z, with frequencies of 5-10% and 1-3%, respectively,” the researchers explained. “Nearly 100 percent of the clinical cases of AATD-associated pathologies involve the PI*Z allele, normally as PI*ZZ homozygous or less frequently as compound heterozygous.”


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Although not an uncommon condition among white individuals, up to 90% of individuals with severe AATD are estimated to be undiagnosed. The long delay in diagnosis, up to 6 years on average, often means it is detected when damage to the lungs is irreversible.

Read more about AATD diagnosis

The usual causes of the delay are a lack of awareness by clinicians and the fact that AATD symptoms are very similar to those of other respiratory diseases, such as asthma and COPD. In addition, patients are not usually tested for AATD unless they have a clinical profile strongly suggestive of the disease.

In terms of this study’s clinical findings, the respiratory pathologies included asthma, COPD, sleep apnea, hypoventilation-obesity syndrome, and nonspecific bronchial hyperreactivity. Regarding genetic findings, the frequency of the PI*S allele in the population of La Palma, Canary Islands, Spain was 8.2%, and the frequency of the PI*Z allele was 2.1%.

The research team found the prevalence of the PI*ZZ genotype in La Palma to be relatively high within the Spanish territory (average, 1/3344). These data suggest the advisability of screening patients in this region, including those with asthma and COPD, with the aim of detecting individuals at high risk of diseases associated with AATD.

Reference

Hernández-Pérez JM, Ramos-Díaz R, Vaquerizo-Pollino C, Pérez JA. Frequency of alleles and genotypes associated with alpha-1 antitrypsin deficiency in clinical and general populations: revelations about underdiagnosis. Pulmonology. Published online March 26, 2022. doi:10.1016/j.pulmoe.2022.01.017