Antiphospholipid antibody ELISAs: survey on the performance of clinical laboratories assessed by using lyophilized affinity-purified IgG with anticardiolipin and anti-beta2-Glycoprotein I activity.

Lupus anticoagulant (LA) and anticardiolipin (aCL) antibodies are the classical tests used to diagnose the antiphospholipid syndrome (APS). Unfortunately, since these are nonspecific and standardization is lacking, the results of laboratory work-ups upon which diagnosis are made are often misleading. The performance of clinical laboratories in detecting LA using lyophilised affinity purified immunoglobulin has been previously reported.

Antibody profiles for the diagnosis of antiphospholipid syndrome.

Among the so called 'antiphospholipid antibodies', the presence of Lupus Anticoagulant (LA) is associated with thrombosis-related events and defines the antiphospholipid syndrome. The role of anti-cardiolipin (aCL) antibodies and anti-human beta2-glycoprotein I (abeta2GPI) antibodies is less striking. Since the problem of standardization for these tests is far from resolved, we evaluated whether the combination of results (antiphospholipid laboratory profiles) could help to better classify these patients.

A comparison between six- and four-week intervals in surveillance of oral anticoagulant treatment.

We determined whether international normalized ratio (INR) monitoring at 6 weeks rather than 4 weeks would benefit patients and reduce costs. Patients receiving stable oral anticoagulation treatment (target INR, 3.0) with a prosthetic mechanical heart valve for more than 6 months were randomized for a maximum interval between INR determinations of 6 weeks (group 1, n = 59) or 4 weeks (group 2 [control], n = 65).

Oral anticoagulant treatment in very elderly patients with atrial fibrillation.

Many factors can influence the final decision to treat nonrheumatic atrial fibrillation in the very elderly patient with anticoagulants. Therefore, a systemic approach in which the thromboembolic and hemorrhagic risk profiles are taken into account is suggested.

Effect of anti-beta2glycoprotein I Lupus Anticoagulants on fibrin polymerization and fibrinolysis.

Anti-beta2-Glycoprotein I (beta2GPI) autoantibodies are the prominent laboratory feature of Hughes syndrome. By prolonging some coagulation tests in the presence of exogenous phospholipids (PL), they behave as classical Lupus Anticoagulants (LA). We investigated the effect of 3 affinity-purified anti-beta2GPI IgG preparations from patients with Hughes syndrome on fibrin polymerization and fibrinolysis of normal plasma, measured by comparing the optical densities of assay mixtures in the presence of the autoantibodies or normal IgG.

Antiphospholipid antibodies are not present in the membrane of gel-filtered platelets of patients with IgG anticardiolipin antibodies, lupus anticoagulant and thrombosis.

To explore the possibility of an interaction between platelets and antiphospholipid antibodies and its relationship with thromboembolic events, platelets from six patients with IgG anticardiolipin antibodies, lupus anticoagulant and thrombosis were isolated by gel filtration. Five patients had primary antiphospholipid syndrome and one had a form secondary to systemic lupus erythematosus. Two patients had mild thrombocytopenia.