Antiphospholipid Syndrome With Isolated Isotype M Anticardiolipin and/or Anti-B2GPI Antibody Is Associated With Stroke

    loading  Checking for direct PDF access through Ovid


Background and Purpose—International classification criteria for antiphospholipid syndrome (APS) include IgM (immunoglobulin M), aCL (anticardiolipin), and aB2GPI (anti-β2-glycoprotein-I) antibodies, but their relevance is still debated. We aimed to assess whether patients with isolated IgM aCL and/or aB2GPI at diagnosis have specific characteristics and outcomes.Methods—We retrospectively included APS patients with isolated IgM antiphospholipid antibodies (isolated-IgM-APS) and compared them to APS patients with IgG and IgM, or IgG alone and/or lupus anticoagulant (nonisolated-IgM-APS).Results—Among the 168 APS patients included, 24 (14.3%) had isolated IgM. Median follow-up was 92.5 months (36–151.5). Isolated-IgM-APS patients were 9.5 years older. At diagnosis, stroke was more frequent in isolated-IgM-APS after adjustment for cardiovascular risk factors (odds ratio, 3.8; 95% CI, 1.3–11.5). IgM isotype remained isolated in 17 of 24 (70.8%) patients over time. Global relapse-free survival did not differ between the two groups. In thrombotic APS, monotherapy with antiplatelet agents was more frequently used in isolated-IgM-APS group with 14 of 20 versus 28 of 134 patients (P<0.0001), with a higher relapse rate with antiplatelet agent alone compared to vitamin K antagonists, especially for patients presenting with a stroke (hazard ratio, 7.37; 95% CI, 1.19–19.0).Conclusions—Isolated IgM APS patients should not be disregarded because they represent 14.3% of an APS population. They have some characteristics: older age at diagnosis and a strong association with stroke. Clinicians must be aware of this situation because antiplatelet agent do not seem to well prevent relapses compared to vitamin K antagonist.

    loading  Loading Related Articles