[A new immune serum globulin preparation for intravenous administration (author's transl)]

A new immune serum globulin preparation has been developed which is suitable for i.v. administration. This product was prepared from Cohn fraction II by selective reduction with dithiothreitol of one or more of the interchain disulfide bonds between the heavy chains and subsequent alkylation of the formed sulfhydryls (about 8--10 per 160 000 daltons) with iodoacetamide. The of these chemical reactions has been termed MISG (modified immune serum globulin). It is free of anticomplement activity, contains essentially all of the antibody potency of immune serum globulin, sediments as essentially a single entity with a sedimentation coefficient of about 7 S, has been freed of all reactants, is non-toxic, and in rabbits is antigenically with normal human immune serum globulin. MISG with its Fc fragment portion intact maintains its complement mediated function as evidenced by its opsonic activity against bacteria. MISG had been tested extensively in vitro, in animals, and in humans. Half-life measurements in humans averaged 22.4 days (range 15.5--28.7 days) and efficacy was demonstrated in a 2-year crossover clinical study in which MISG was compared with normal immune serum globulin administered i.m.