CD40LG and deep vein thrombosis: The 1999 Sapporo classification criteria for APS included laboratory criteria of the lupus anticoagulant or medium to high titre aCL IgG or IgM positive over 6 weeks.25 The Sydney revision added a new requirement that the aPL antibody must be repeatedly positive over 3 months.26–32 Clinical criteria (thrombosis and pregnancy related) had to be present within 5 years of the positive aPL antibody assay.