Evaluation of a modified procedure for Staclot LA for the confirmation of lupus anticoagulants.

Staclot LA is a hexagonal (II) phase phospholipid clotting assay used to confirm the presence of lupus anticoagulants (LA). However, there have been complaints that the procedure contains several incubation steps requiring 15 min of operator time. The authors were able to shorten this procedure to a single 5 min incubation without affecting assay sensitivity. Both procedures were performed on 45 known lupus anticoagulant positive specimens, 25 normal donors, eleven plasmas from patients with known factor VIII or factor V inhibitors and ten other specimens submitted for lupus anticoagulant or anticardiolipin antibody testing but without complete testing to confirm the presence of LA prior to testing with Staclot LA. Excellent agreement was observed between the two procedures with concurrence in 87 of 91 specimens (95.6%). Each method detected 39 of 45 LA positive specimens giving a sensitivity of 86.7%. This modification shortens technologist time by two-thirds without compromising assay sensitivity, which will allow for automation on commonly used coagulation analysers.