VARIOUS abnormalities of serum Proteins and autoimmune phenomena have been reported in conjunction with schizophrenic illness.1 This study reports differences in the major immunoglobulin (yglobulin) classes, IgG, IgA, and IgM, among hospitalized acute, chronic and remitted schizophrenic patients, nonschizophrenic psychiatric patients, and nonmental patient controls. Background Elevation of y-globulin2-8 and of 19S macroglobulin9,10 has been reported in the sera of acute and chronic schizophrenic patients. Hypermacroglobulinemia was not found in a group of drug-free schizophrenic patients11 nor correlated with illness in monozygotic twins discordant for schizophrenia.12 Solomon and co-workers found a slight positive correlation between severity of psychotic symptoms and 19S level in chronic schizophrenic patients.13 Qualitative as well as quantitative disturbances in electrophoretic serum protein patterns in schizophrenic patients (some (drug-free) have been described including: splitting of α2globulin, a line superimposed in the gamma