HEPARIN MONITORING IN ACUTE THROMBOSIS ASSOCIATED WITH ANTIPHOSPHOLIPID ANTIBODY SYNDROME

Antiphospholipid antibody syndrome is associated with recurrent thromb oembolism and the presence of antibodies directed against negatively c harged phospholipids. Despite significant hypercoagulability, patients with the disorder often have elevated baseline activated partial thro mboplastin times. Although heparin is indicated for the treatment of a cute thrombosis, heparin monitoring is complicated by laboratory test interference. A practical treatment approach involves patient-specific screening for a reagent insensitive to the presence of the inhibitor, and determination of a reagent-specific therapeutic range in seconds that corresponds to heparin serum concentrations of 0.2-0.4 U/ml. Othe r monitoring methods, including using the patient's baseline activated partial thromboplastin time or using an antifactor Xa activity assay, have not been reported or studied but may offer alternatives for hepa rin monitoring in patients with coagulation laboratory test interferen ce associated with antiphospholipid antibody syndrome.