In autoimmune disease, anti-apolipoprotein H (AAHA) antibodies, also called anti-β 2 glycoprotein I antibodies, comprise a subset of anti-cardiolipin antibodies and lupus anticoagulant.. Apolipoprotein H (Apo-H), previously known as β 2-glycoprotein I and beta-2 glycoprotein I, is a 38 kDa multifunctional apolipoprotein that in humans is encoded by the APOH gene . Abstract. AIMS--To investigate the effect of beta 2-glycoprotein I (beta 2 GPI) on the thrombin/thrombomodulin dependent activation of protein C; and to determine whether beta 2 GPI dependent anticardiolipin antibodies have any effect.. The persistent presence of IgG and/or IgM beta 2 glycoprotein I (B2GPI) antibodies (greater than 99th percentile) is a laboratory criterion for the diagnosis of antiphospholipid syndrome (APS).. . .