Anti-β2-glycoprotein I autoantibodies from patients with the “antiphospholipid” syndrome bind to β2-glycoprotein I with low affinity : dimerization of β2-glycoprotein I induces a significant increase in anti-β2-glycoprotein I antibody affinity - Sheng, Y; Kandiah, DA; Krilis, SA (J Immunol, 1998)