Detection of multiple annexin autoantibodies in a patient with recurrent miscarriages, fulminant stroke and seronegative antiphospholipid syndrome

Anti-phospholipid syndrome (APS) is one of the main causes for recurrent miscarriages. The diagnosis of APS is based on the occurrence of clinical symptoms such as thrombotic events or obstetric complications as well as the detection of antiphospholipid antibodies directed against β2-glycoprotein I and cardiolipin, or a positive lupus anticoagulant assay. However, there is a subpopulation of patients with clinical symptoms of APS, but the lack of serological markers (seronegative APS). In addition, a large proportion of patients with unexplained recurrent miscarriages exist. These cases may be attributed, at least in part, to a seronegative APS.
The presence of autoantibodies against annexins is potentially associated with APS. Here we used immunoassays and immunoblots to detect autoantibodies directed against annexin A1-5, and A8, respectively, in a patient with a seronegative APS and a history of six recurrent pregnancy losses and fulminant stroke. We found strong IgM isotype antibody reactivity directed against annexin A2 and annexin A8, and moderate to weak IgM isotype antibody reactivity directed against annexin A1, A3, and A5. Further studies will evaluate the diagnostic value of IgM isotype antibodies against annexin A1-A5, and A8 for seronegative APS and recurrent miscarriages.