Absence of plasma protease-antiprotease imbalance in the formation of saccular cerebral aneurysms.
OBJECTIVE
We examined the hypothesis that a plasma protease-antiprotease imbalance contributes to the formation of saccular cerebral aneurysms and the suggestion that the assay of these enzymes might be a screening tool for people at higher risk for aneurysm formation.


METHODS
From June 1997 through May 1998, the plasma leukocyte elastase, which is an important proteolytic enzyme, and alpha-antitrypsin and alpha2-macroglobulin, which are important antiproteolytic enzyme plasma proteins, were examined in 18 patients with ruptured aneurysms, 9 patients with unruptured aneurysms, and 22 controls.


RESULTS
The elastase:alpha1-antitrypsin ratio and the elastase:alpha2-macroglobulin ratios were significantly higher in patients with ruptured aneurysms within 24 hours after subarachnoid hemorrhage (SAH) than in the controls. The protease-antiprotease imbalance depended on the elevation of the elastase level, which might be correlated with leukocytosis after SAH. The elastase level decreased to the control level 3 months after the onset of SAH. No significant difference in the elastase:alpha1-antitrypsin and elastase:alpha2-macroglobulin ratios was observed between the patients with unruptured aneurysms and the controls.


CONCLUSIONS
These results do not support the hypothesis that a plasma protease-antiprotease imbalance is a potential marker to predict the formation of saccular cerebral aneurysms. The increase in plasma elastase levels in patients with ruptured aneurysms might be attributable to leukocytosis after SAH.
Department of Neurosurgery, Shimizu Kosei Hospital, Japan.
N
N
Sakai
K
K
Nakayama
Y
Y
Tanabe
Y
Y
Izumiya
S
S
Nishizawa
K
K
Uemuara
D000328:Adult; D000368:Aged; D017542:Aneurysm, Ruptured / Q000175:diagnosis / Q000201:enzymology* / Q000601:surgery; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis / Q000201:enzymology* / Q000601:surgery; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D010196:Pancreatic Elastase / Q000097:blood*; D012307:Risk Factors; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis / Q000201:enzymology* / Q000601:surgery; D000515:alpha 1-Antitrypsin / Q000378:metabolism*; D000511:alpha-Macroglobulins / Q000378:metabolism*
D000515:alpha 1-Antitrypsin; D000511:alpha-Macroglobulins; D010196:Pancreatic Elastase