International classification criteria for antiphospholipid syndrome: synopsis of a post-conference workshop held at the Ninth International (Tours) aPL Symposium.

An international workshop on classification criteria for antiphospholipid syndrome (APS) was held on 16 September 2000 in Tours, France, following the Ninth International APS Symposium. The workshop addressed issues that were not resolved by the previous (1998) international workshop on the classification criteria. Participants at the workshop agreed that no changes should be made to the international (Sapporo) criteria at the present time. However, to improve the criteria, future efforts should be focused on the following: (1) further evaluation of the international (Sapporo) criteria for definite APS; (2) definition of other categories of APS such as 'probable' and 'possible' APS; (3) guidelines for the clinical diagnosis as distinct from classification of APS; (4) strategies to improve the compliance of laboratories worldwide, with recommended procedures for Lupus anticoagulant (LA) and anticardiolipin (aCL) assays; (5) development of monoclonal antibody standard reagents for aCL and LA assays; and (6) refinement and subsequent evaluation of antibeta2GPI assays for use in idenfitication of APS.