LAUSR

Anti-beta-2 glycoprotein I antibodies (anti-B2GPI) are often cited as the major pathogenically relevant antibody in antiphospholipid syndrome (APS), but it is unclear if there is clinical evidence to support this theory. We performed a systematic review to determine if IgG anti-B2GPI positivity was independently associated with thrombotic and/or obstetric manifestations of APS. We searched MEDLINE, EMBASE, The Cochrane Library, and ClinicalTrials.gov electronic databases through April 2020 for prospective studies that met pre-specified design criteria. Of 4758 articles identified through computer-assisted search, 4 studies examining obstetric outcomes and 2 studies examining thrombotic outcomes were included for qualitative assessment. The presence of anti-B2GPI had only a weak independent association with thrombosis and was, at best, inconsistently associated with obstetric complications. A quantitative assessment could not be performed due to study heterogeneity. The overall quality of the evidence was very low. Although anti-B2GPI are commonly thought to mediate APS manifestations, clinical evidence is lacking with very low-quality data to support a weak association with thrombosis.