Alpha 1-antitrypsin Pi-types in 965 COPD patients

Area of Science:

• Pulmonary Medicine
• Genetics
• Biochemistry

Background:

• Alpha-1-antitrypsin (AAT) deficiency is a genetic condition that can lead to lung diseases.
• Intermediate AAT deficiency, specifically the MZ phenotype, is suspected to play a role in chronic obstructive pulmonary disease (COPD).

Purpose of the Study:

• To investigate the association between intermediate AAT deficiency (Pi-types and serum-trypsin-inhibitory-capacity) and COPD.
• To determine the prevalence of different AAT phenotypes in COPD patients compared to controls.

Main Methods:

• Analysis of AAT Pi-types and serum-trypsin-inhibitory-capacity (STIC) in 965 COPD patients.
• Comparison of AAT phenotypes in COPD patients with control groups from previous studies and an in-house control group.

Main Results:

• The MZ phenotype, indicative of intermediate AAT deficiency, was found in 8.0% of COPD patients versus 2.9% in controls (p < .0005).
• ZZ homozygosity was detected in 1.9% of COPD patients, significantly higher than controls (0.04%).
• ZZ homozygotes were younger on average than the general COPD patient group.

Conclusions:

• Intermediate AAT deficiency, particularly the MZ phenotype, appears to predispose individuals to developing COPD.
• While AAT deficiency contributes to COPD, its overall prevalence in COPD patients is relatively small (around 10%).
• The MS phenotype was not found to be increased in this COPD patient cohort.