Free protein S deficiency in acute ischemic stroke. A case-control study.
OBJECTIVE
Deficiency of free protein S, a naturally occurring anticoagulant, may be acquired in the setting of acute illness and increasingly has become recognized as a possible stroke risk factor. We sought to determine whether free protein S deficiency is associated with acute cerebral infarction among older individuals at risk for stroke.


METHODS
Free protein S was measured by Laurell rocket immunoelectrophoresis in 94 adults admitted for acute cerebral infarction and in 94 hospitalized control subjects of similar age, sex, and race. Patients with a history of cerebrovascular disease, acute thrombotic or hematologic diseases, or medical conditions known to cause free protein S deficiency were excluded from the control group.


RESULTS
The percentage of patients with free protein S deficiency (< 20% normal total protein S) was similar in the case and control groups (21% versus 20%, respectively). Among all subjects, free protein S deficiency was more common in blacks than nonblacks (34% versus 13%, p = 0.001). A very low free protein S (< 15% normal total protein S) was more frequent among case patients than control subjects (11% versus 5%), but this trend failed to reach statistical significance.


CONCLUSIONS
Free protein S deficiency is common among hospitalized patients, even in the absence of a recognized predisposing condition. Our findings indicate that acquired deficiency of free protein S is not a major risk factor for ischemic stroke.
Mayer
S A
SA
Department of Neurology, Columbia-Presbyterian Medical Center, New York.
Sacco
R L
RL
Hurlet-Jensen
A
A
Shi
T
T
Mohr
J P
JP
D000208:Acute Disease; D000368:Aged; D044383:Black People; D016022:Case-Control Studies; D002544:Cerebral Infarction / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018455:Protein S Deficiency; D044465:White People