Alleles of the alpha-1-antitrypsin phenotype in patients with aortic aneurysms.

OBJECTIVE

To examine the possible significance of homo- or heterozygous alpha-1-antitrypsin deficiency in the pathogenesis of aortic aneurysms (AA).

DESIGN

Prospective investigation.

SETTING

University hospital.

PATIENTS

300 controls representing the general population in our region of Southern Germany and 126 patients with aneurysmectomy and graft insertion.

METHODS

The alpha-1-antitrypsin phenotype was determined by employing isoelectric focusing. Each patient was also evaluated for hypertension, lipometabolic dysfunction, smoking, hyperuricemia, and diabetes mellitus.

MAIN OUTCOME MEASURES

The frequency and distribution of alpha-1-antitrypsin phenotypes and risk factors.

RESULTS

115 of 126 patients presented with one or several of the conventional risk factors: hypertension (61.5%), lipometabolic dysfunction (36.9%), smoking (58.4%), hyperuricemia (13.8%), or diabetes mellitus (6.9%). The following frequencies of alpha-1-antitrypsin phenotypes were determined: PiMM (82.5%), PiMV (4.7%), PiML (1.5%), PiMS (7.1%), PiSS (0.7%), PiMZ (3.0%). Indeed, when compared to the general population (control group) the percentage of the normal PiMM phenotypes was lower in the group of patients with AA (p<0.001). However, in our study this significant difference was not primarily due to the presence of patients homozygous or heterozygous for deficiency alleles PiMS, PiSS and PiMZ (p=0.0523) as has been previously reported, but rather to the high prevalence of the variants PiMV (p<0.005).

CONCLUSIONS

Our study suggests that not only Pi-deficiency alleles, previously identified as being associated with AA, but also that Pi variants may play a pivotal role in the pathogenesis of AA.