Antithrombin Milano: A New Variant With Monomeric and Dimeric Inactive Antithrombin III

摘要: A qualitative defect of antithrombin III (AT III) has been demonstrated over three generations in eight members an Italian family by the discrepancy between a normal amount antigen and decreased anti-Xa activity presence or absence heparin. By two-dimensional immunoelectrophoresis heparin, two peaks AT were present all patients9 plasma. was purified from propositus plasma sulfate dextran precipitation followed heparin affinity chromatography. The elution profile patient9s abnormal allowed separation populations III, abnormal. first fraction (normal contained activity, migrated as single peak sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE), band with molecular weight (mol wt) identical to that (60,000). Conversely, last fraction, devoid SDS-PAGE, bands observed: one mol wt 60,000 second 120,000. Western blots clearly cross-reactivity 120,000 monospecific antisera human III. Reduction converted it band, suggesting dimeric form name Milano is proposed for this new variant.