Incidence of Alpha-1 Antitrypsin Z and S Alleles in Patients with Granulomatosis with Polyangiitis—Pilot Study

Abstract

Deficiency alleles PI*Z and PI*S were detected in 3 (5.88%) and in 2 patients (3.92%) with GPA, respectively. All of them were cANCA positive. In the controls, PI*Z was observed in 2.8% while PI*S in 1.5% of cases. Accordingly, the increased incidence of main deficiency alleles was demonstrated in GPA, and particularly in cANCA+GPA patients, when compared to the controls. The estimated frequency for PI*Z in GPA, cANCA+GPA patients and controls was, respectively, 29.4/1000, 34.9/1000 and 13.7/1000, whereas for PI*S it was 19.2/1000, 23.2/10,00 and 7.6/1000. However, the observed differences did not reach statistical significance due to the considerable size disproportion between groups. CONSCLUSIONS: We believe that our preliminary data confirm the clinical importance of AAT deficiency in GPA patients and the need to screen for AAT deficiency alleles. The study is on-going.