COMPARATIVE-STUDY OF ANTIPHOSPHOLIPID ANTIBODY DETECTION IN 11 BELGIAN LABORATORIES

Twenty-six plasma samples have been sent to 11 different Belgian labor atories in order to detect the presence of antiphospholipid antibodies , either by immunological methods and/or by coagulation tests. A good concordance between Laboratories was observed for coagulation tests. L aboratories using detection tests and performing mixing procedures and neutralisation procedures displayed the highest sensitivity as compar ed with laboratories which did not perform one of these two latter pro cedures. The concordance between laboratories for the immunological me thods was much worse as compared with coagulation tests. This may be a ttributable either to an intrinsic problem of the immunological tests or to a selection bias due the fact that the plasmas used in this stud y were selected in coagulation laboratories only where the chance to f ind a lupus anticoagulant positive/ELISA antiphospholipid negative sam ple is high.