Some Immunological Investigations on Antithrombin III ‘Budapest’

Immunoelectrophoretic studies were carried out on plasma from a patient with an abnormal antithrombin III molecule (antithrombin III 'Budapest'). One-dimensional immunoelectrophoresis using a commercial antibody to antithrombin III (antibody to alpha2-AtIII) showed two precipitin peaks of alpha2-AtIII antigen. Two-dimensional immunoelectrophoresis showed two precipitin peaks, one with normal electrophoretic mobility, the other with increased electrophoretic mobility. It was shown that alpha2-AtIII antigen with normal mobility was identical to normal alpha2-AtIII, and that the alpha2-AtIII antigen with increased electrophoretic mobility was antigenically deficient, and appeared to be present in higher concentration than the normal alpha2-AtIII antigen. Although one-dimensional immunoelectrophoresis on plasma from the patient's son showed only one peak, two-dimensional immunoelectrophoresis revealed that the son also had two populations of alpha2-AtIII, one with normal mobility, the other with increased mobility. However, the alpha2-AtIII antigen with normal mobility appeared to be present in higher concentration than the alpha2-AtIII antigen with increased mobility. One- and two-dimensional immunoelectrophoresis using a different commercial antibody to alpha2-AtIII showed only one precipitin peak using the patient's plasma. The precipitin peak observed following two-deminsional immunoelectrophoresis was asymmetric and showed increased mobility.