The prevalence of NPSLE was high in this cohort of unselected patients with SLE. Headaches, cognitive dysfunction, and psychiatric disorders were the most common NPSLE syndromes seen. These results will be easily comparable to other studies also using standardized diagnostic criteria. However, the lack of ethnicity and language-matched normative neuropsychological data may make comparisons of cognitive dysfunction in SLE populations difficult.

Platelet aggregometry has been the reference method employed to detect, diagnose, and monitor qualitative platelet disorders since the early 1960s. Lumiaggregometry and impedance-based whole blood lumiaggregometry have advantages over light transmittance aggregometry in that they provide for enhanced specimen management and increase the test sensitivity to impairment of platelet granule secretion. Whole blood lumiaggregometry detects and identifies congenital and acquired platelet plasma membrane receptor defects, metabolic pathway secretion disorders, and storage pool deficiency. Whole blood lumiaggregometry is also being applied to antiplatelet therapy monitoring and identifies aspirin and thienopyridine resistance. There is growing interest in using impedance-based whole blood lumiaggregometry for near-patient whole blood platelet analysis and antiplatelet therapy monitoring. This article will also discuss other whole blood testing processes for assessing platelet function, particularly as applied to assessing the effect of antiplatelet medication.

Background and Purpose-Antiphospholipid antibodies have been associated with ischemic stroke in some but not all studies. Methods-We performed a population-based case-control study examining antiphospholipid antibodies (anticardiolipin antibodies and lupus anticoagulants) using stored frozen sera and plasma in 160 cases and 340 controls enrolled in the Stroke Prevention in Young Women study. We evaluated for the presence of anticardiolipin antibody (IgG, IgM, and IgA isotypes) by an enzyme-linked immunosorbent assay and for the lupus anticoagulant using several phospholipiddependent coagulation tests (activated partial thromboplastin time, dilute Russell's viper venom time) with mixing studies. If mixing studies were prolonged, confirmatory tests were performed. A ntiphospholipid antibodies (aPLs) are a group of antibodies directed against phospholipids or phospholipidprotein complexes. These antibodies have been linked to a clinical syndrome consisting of thrombosis, thrombocytopenia, and recurrent fetal loss. Much work has been done in efforts to determine whether any antibody characteristics are associated with a greater thrombotic risk, and several have been suggested. 1,2 The presence of a lupus anticoagulant (LA), an aPL that is detected with a phospholipid-dependent coagulation test, appears to be associated with a greater thrombotic risk for both venous and arterial thrombosis. 3 Cerebral ischemia associated with aPL is the most common arterial manifestation. 4,5 However, the importance of aPL as a cardiovascular risk factor is controversial. A number of case-control studies have found an association between aPL and incident ischemic stroke, 6 -14 but others have not. [15][16][17] Several prospective studies have also found an association See Editorial Comment, page 2400 between aPL and stroke and myocardial infarction. 18 -20 Many studies evaluated only for anticardiolipin antibodies (aCL) using an enzyme-linked immunosorbent assay technique. Thus, an important association between the more "high-risk" aPL, the LA, could have been missed. In addition, prior studies 8,13 have suggested that aPLs are more strongly associated with stroke in young adults. We evaluated the association between several types of aPLs (aCL and LA) and the risk of stroke in women enrolled in a population-based case-control study, the Stroke Prevention in Young Women Study. MethodsThe Stroke Prevention in Young Women Study is a population-based case-control study initiated to study risk factors for ischemic stroke Cases were women 15 to 44 years of age with a first cerebral infarction, identified by discharge surveillance at all 59 hospitals in the study area and through direct referral by regional neurologists. The methods for discharge surveillance, chart abstraction, case adjudication, and assignment of probable and possible underlying causes have been previously described. 21,22 Recruitment within 1 year of stroke was required for participation. Of 291 cases who were both eligible and identified within the 1-year time wind...