The international surgical journal with global reach

This is the Scientific Surgery Archive, which contains all randomized clinical trials in surgery that have been identified by searching the top 50 English language medical journal issues since January 1998. Compiled by Jonothan J. Earnshaw, former Editor-in-Chief, BJS

Genetic approach to the role of cysteine proteases in the expansion of abdominal aortic aneurysms. BJS 2004; 91: 86-89.

Published: 3rd November 2003

Authors: P. Eriksson, K. G. Jones, L. C. Brown, R. M. Greenhalgh, A. Hamsten, J. T. Powell et al.

Background

The elastinolytic cysteine proteases, including cathepsins S and K, are overexpressed at sites of arterial elastin damage. Cystatin C, an inhibitor of these enzymes, is expressed in arterial smooth muscle cells; an imbalance in cystatin C has been implicated in the aortic wall degeneration observed in abdominal aortic aneurysms (AAAs). The aim of the study was to investigate the impact of a polymorphism in the signal peptide of the cystatin C gene on the growth of small AAAs.

Method

Some 424 patients with a small AAA (4·0–5·5 cm) were monitored for AAA growth by ultrasonography and provided a DNA sample for analysis of the + 148 G > A polymorphism in the cystatin C signal peptide and the—82 G > C polymorphism in the gene promoter. The median length of follow‐up was 2·8 years and AAA growth rates were calculated by linear regression analysis.

Results

For patients of + 148 GG (n = 263), GA (n = 147) and AA (n = 20) genotypes, the mean(s.d.) AAA growth rates were 0·37(0·29), 0·37(0·23) and 0·30(0·26) cm, and initial diameters were 4·58(0·35), 4·58(0·35) and 4·62(0·36) cm, respectively. Patients of + 148 AA genotype had a slower aneurysm growth rate (unadjusted P = 0·058; after adjustment for age, sex, initial AAA diameter and smoking, P = 0·027). There also was a trend for the rare homozygotes of the—82 C allele to have slower AAA growth (adjusted P = 0·055). Smoking history had a stronger association with aneurysm growth (P = 0·003).

Conclusion

There was a weak association between variation in the cystatin C gene and AAA growth. Medical strategies to limit AAA growth might include the inhibition of cysteine proteases. Copyright © 2003 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

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