237 Ischaemic stroke in systemic lupus erythematosus, -distribution of subtypes and a risk genotype in the stat4 gene

Background and aims We investigated the distribution of ischaemic stroke subtypes, classified according the Trial of Org 10 172 in Acute Stroke Treatment (TOAST) system, among patients with systemic lupus erythematosus (SLE). Genetic susceptibility in the signal transducer and activator of transcription factor 4 ( STAT4 ) gene, defined by the single nucleotide polymorphism (SNP) rs10181656(G) were explored. Methods We identified 69/665 SLE patients with stroke. Medical charts were retrieved and brain, cardiac and vascular imaging at the time of stroke were examined. Classification was performed according to TOAST: large-artery atherosclerosis (LAA), cardioembolism (CE), small-artery occlusion (SAO), stroke of other determined aetiology (OC) and stroke of undetermined aetiology (UE). Occurrence of the anti-phospholipid syndrome (APS) was documented. Evaluators were blinded to genotypes. General population controls (n=658) and SLE patients free from previous cerebrovascular disease (n=517) were used as comparators. Results 56/69 patients with ischaemic stroke had charts with sufficient information for TOAST classification. Median age was 52 (17-84) years, 91% were female. All strokes classified as OC were attributed to APS. TOAST classification is presented in Table 1. Stroke of OE/APS and CE origin were associated with the STAT4 risk genotype as presented in Table 2. Conclusions The majority of ischaemic strokes among SLE patients were of APS or CE origin. These two subtypes were associated with genetic susceptibility in the STAT4 gene. Patients with APS associated strokes were remarkably young. STAT4 genotype could, in addition to antiphospholipid antibodies and echocardiography, add information about stroke risk and help identify patients who will benefit from prophylactic anticoagulation treatment.