A new study has assessed the genotypic frequency of alpha-1 antitrypsin deficiency (AATD) in Turkey and found rare variants of alpha-1 antitrypsin (AAT) to be more common than expected.
The study, published in the Turkish Journal of Medical Sciences, noted that the percentage of patients with the homozygous Pi*ZZ genotype was 0.51%, but when heterozygous AAT gene variants and single point mutations were included, the frequency increased to 7.1%.
“Although there are few AATD-related studies conducted with the general population and other patient groups in our country, as far as we know, there is no study in which the frequency of AATD was determined in [chronic obstructive pulmonary disease (COPD)] patients,” the authors wrote. “For this reason, a SERPINA1 genotype study was conducted on consecutive COPD patients admitted to our hospital to determine the frequency of AATD in COPD patients in our country.”
The research team conducted a prospective, cross-sectional study between February 2020 and February 2022 on 186 patients with COPD, 158 of whom were men, at a single center in Turkey.
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Blood samples were obtained from all patients, and their demographics, comorbidities, and clinical characteristics were recorded. Serum and dried blood spot samples were used to assess the presence of AATD and the frequency of variants such as Pi*ZZ, Pi*MZ, Pi*S, and Pi*MM.
The results revealed that the frequencies of both homozygous and heterozygous AAT gene variants among patients with COPD were higher than expected. The Pi*S variant was not detected, but other rare variants were found, at higher frequencies than previously thought.
As expected, serum levels of AAT were lower in patients with variants. The authors recommend that clinicians consider and investigate the possibility of AATD in their patients with COPD.
Çörtük M, Demirkol B, Arslan MA, et al. Frequency of alpha-1 antitrypsin deficiency and unexpected results in COPD patients in Turkey; rare variants are common. Turk J Med Sci. 2022;52(5):1478-1485. doi:10.55730/1300-0144.5486