plasma proteins in schizophrenia: a review*

Studies of the blood proteins of schizophrenic patients have been reported frequently. If qualitative or quantitative differences between schizophrenics and other groups could be found in these investigations, they would be useful diagnostically and might provide insight into etiology. Studies of blood proteins are of two major types: 1) Investigations in which analytic methods are used to determine whether the concentration or characteristics of one or more blood protein fractions differ from normal in schizophrenic patients. 2) Investigations in which bioassay techniques are used to determine the presence or concentration of a protein characterized by a given biological activity. Examples of the latter approach include 1) determination of plasma enzyme levels; 2) assaying for specific antigens or antibodies through the use of immunological reactions; and 3) assaying the effects of the serum or plasma of schizophrenics on metabolic, physiologic, or behavioral reactions of various biological systems including cell suspensions, tissue slices, and intact organisms. Historically, studies in the bioassay category date back to 1890 when the first attempts were made to find a toxic substance in the body fluids of schizophrenics, and they have been reviewed numerous times since (Bock and Rafaelsen 1974, Eiduson et al. 1964, Fessel 1962, Kety 1959, Weil-Malherbe and Szara 1971, and Wyatt, Termini, and Davis 1971). Several recent reports in the Russian literature describe new bioassay and cytotoxic effects of blood fractions drawn from