Guidelines on the investigation and management of the antiphospholipid syndrome.

In 1991, the Haemostasis and Thrombosis Task Force of the British Society for Haematology published guidelines on testing for the lupus anticoagulant (LA) (Machin et al, 1991). Since then there have been major developments in our understanding of the nature of `antiphospholipid antibodies' (aPLs) and improvements in our knowledge of the clinical course of the antiphospholipid syndrome. These revised guidelines have been prepared against this background. They cover both clinical and laboratory aspects.