Immunoglobulin G is the only anti-beta-2-glycoprotein I isotype that associates with unprovoked thrombotic events among hospital patients

Antiphospholipid autoantibody detection is important in all patients with systemic autoimmune diseases

“…IgM detection such an association was not observed as reported in a study conducted in 796 patients with SLE [26]. This statement was confirmed by other authors who failed to associate aCL±aβ2GPI IgM positivity in patients with primary and secondary APS manifestations with thrombosis [27,28]. The two greatest risk factors for miscarriage are elevated levels of aPL and a history of previous fetal loss as these women have up to 80% risk of current pregnancy loss [31].…”

Low level autoantibodies can be frequently detected in the general Australian population

“…20 In two AAb assays (b2GPI IgM and TPO) an RV at the 95th percentile was clearly above the manufacturer's cut-off, and would warrant a review of local population data to establish an RV; however, the b2GPI IgM AAb assay may have limited clinical value. 55 In regards to the TPO AAb findings, a previous study has demonstrated that an underestimate of the level of evolving thyroid disease within the general population is likely and the threshold set by the manufacturer may capture early disease. 57 Only very limited data have been published for Australian general population cohorts to date; this includes a study of the Busselton population in 1972 using a more limited range of assays, some of which are now historic.…”

The Significance of Anti-Beta-2-Glycoprotein I Antibodies in Antiphospholipid Syndrome

“…Another study looked at the ability of anti-B2GPI isotypes to stratify thrombotic risk in patients with lupus anticoagulant, and found that those with IgG anti-B2GPI had a higher incidence of thrombosis whereas there was no association for IgM anti-B2GPI [22]. A recent study from Western Australia assessed the clinical phenotype of 128 hospital patients who had tested positive for at least one anti-B2GPI isotype [23]. There was a higher proportion of patients with a history of unprovoked venous and arterial thrombosis among those who were IgG anti-B2GPI positive compared to those who lacked IgG anti-B2GPI.…”