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.
Sakai
N
N
Department of Neurosurgery, Shimizu Kosei Hospital, Japan.
Nakayama
K
K
Tanabe
Y
Y
Izumiya
Y
Y
Nishizawa
S
S
Uemuara
K
K
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