Anti-β2-glycoprotein I antibodies and ischemic stroke in a 20-month-old boy

Antibodies to beta2-glycoprotein I (anti-beta2GPI) have been associated with recurrent thrombosis and pregnancy morbidity. However, the prevalence of anti-beta2GPI in children suffering from cerebral infarction is unknown. We report on a 20-month-old boy who had an ischemic stroke, secondary to antiphospholipid syndrome with high titers of immunoglobulin G anti-beta2GPI (first titer: 132 U; second titer 6 weeks later: 350 U; normal range: 0-100 U). Anticardiolipin antibodies and lupus anticoagulant tests were negative. All other causes of infarction were excluded. Laboratory studies showed anti-beta2GPI IgG levels of 164 U and 216 U at 6 months and 2 years, respectively, after the onset. The patient received treatment with low-dose aspirin. To our knowledge, this is the first reported case of childhood ischemic stroke with only anti-beta2GPI but no antibodies detectable in standard antiphospholipid assays. This case supports the recommendation of others to search for these antibodies in the presence of strong clinical suspicion of antiphospholipid syndrome, when anticardiolipin antibodies and lupus anticoagulant tests are negative.