Immunohematologic characteristics of infection-associated cerebral infarction.

We evaluated 50 consecutive patients with acute ischemic stroke to assess the prevalence of systemic infection preceding the neurological event. We analyzed the immunohematologic characteristics of patients with and without signs and/or symptoms of a preceding infectious process. Patients were examined less than or equal to 7 days after cerebral infarction and evaluated for fibrinogen, anticardiolipin antibodies, fibrin D-dimer (a fragment of cross-linked fibrin), plasminogen activator inhibitor-1, and protein S. Of the 50 patients, 17 had symptoms of infection beginning less than or equal to 1 month before the stroke (11 had upper respiratory tract infections, three urinary tract infections, two subacute bacterial endocarditis, and one pneumonia). Compared with patients without infection, patients with infection had significant increases in fibrin D-dimer concentration (5.3 +/- 1.1 versus 4.7 +/- 0.9 log-transformed ng/ml, p less than 0.05) and cardiolipin immunoreactivity, IgG isotype (1.8 +/- 1.3 versus 1.1 +/- 0.9 log-transformed phospholipid units, p less than 0.04), and, when studied less than or equal to 2 days after the stroke, increased fibrinogen levels (459 +/- 126 versus 360 +/- 94 mg/dl, p less than 0.05). In conclusion, infection-associated cerebral infarction is common and is associated with substantial immunohematologic abnormalities.