Process for the separation of antifactor VIII:C antibodies, more particularly usable for the purification of the blood plasma of a type a hemophiliac

A process for the separation of antiVIII:C antibodies present in a liquid, which comprises:

• (a) contacting said liquid with a solid support constituted by a polymer or copolymer having substitutable groups in its chain and whereof at least part is substituted by
• groups of formula --(SO.sub.3).sub.x M, in which M represents a metal which does not react with the liquid and x represent the valency of M,
• groups of formula --SO.sub.2 Y, or
• groups of formula --COY, in which Y represents a radical obtained by removing a hydrogen atom from the amino function of an .alpha.-amino acid other than arginine or an .alpha.-amino acid derivative other than arginine having an affinity for antiVIII:C antibodies and a selectivity for antiVIII:C antibodies with respect to other immunoglobulins and
• (b) separating the liquid from the support on which have been adsorbed the antiVIII:C antibodies.