Phosphatidylserine IgG and beta-2-glycoprotein I IgA antibodies may be a risk factor for ischaemic stroke

Abstract

Antiphospholipid antibodies (APLA) are established risk factors for venous thrombosis but their role in the pathogenesis of cerebral ischaemia is unclear. The purpose of the present study was to evaluate the relevance of various APLA in patients with cryptogenic stroke (group A, n = 21) and determined causes of stroke (group B, n = 104) according to the TOAST classification in comparison with healthy volunteers without any thrombotic or ischaemic event in their history (group C, n = 84). Median ages were 52 yr (A), 60 yr (B) and 51 yr (C). Blood samples were tested for lupus anticoagulant (LA) using phospholipid-dependent coagulation tests (activated partial thromboplastin time, diluted Russell viper venom time). Confirmatory tests were performed if necessary. Furthermore, we assessed the presence of specific APLA and their antibody subclasses against cardiolipin (AclA), phosphatidylserine (ApsA), phosphatidylinositol (ApiA) and beta-2-glycoprotein I (Abeta2A) using enzyme-linked immunosorbent assay. For ApsA IgG we found a significantly higher prevalence in stroke patients (57.7%) compared with normal subjects (4.8%; P < 0.001). Similarly, Abeta2A IgA was significantly more prevalent in stroke patients (20.8%) in comparison with normals (3.6%; P < 0.001). For all other APLAs tested, no significant differences emerged after adjustment for multiple comparisons. We did not find significant differences between stroke subtypes for any APLA. The results of this study suggest a relevant role for antiphosphatidylserine IgG and anti-beta2-glycoprotein I IgA in stroke aetiology.