APOH and systemic lupus erythematosus: Visvanathan et al. (33) studied the response of PBMCs to native plasma-derived β2GPI using a serum-free system in 24 aPL-positive (anti-CL- or lupus anticoagulant [LA]-positive) individuals, 7 aPL-negative individuals with various autoimmune diseases (including SLE), and 15 healthy controls.