Antibodies to human heat shock protein in patients with schizophrenia and major depression

Different immunological abnormalities were reported in schizophrenia and major depression. Heat shock proteins are produced in every cell type in reaction to different stressors. They are found in cells in normal conditions in minor quantities. In autoimmune diseases they were found in large quantities. Kilidries et al. reported an increase of hsp60 antibodies in the serum of patients with schizophrenia. The serum of 26 patients with schizophrenia, 8 with major depression and 22 normal subjects, were tested for the presence of hsp antibodies. The serum samples were tested for antibody binding to protein extracts of IMR-32 neuroblastoma cell line on Western blots. In Western blots IgG in the serum of all patients but one, and of normal subjects, reacted with a protein of 60 kD. The intensity of each band in the 60 kD region was quantified in a scale of four groups. No significant differences were found among the three groups. On the other hand, IgG of 8 patients with schizophrenia (30.71%) formed a band in the region of 85 kD. This band was not formed with the serum of other groups. hsp60 kD is an antigen of many pathogens and antibodies against it can be a result of an infection and may thus not be a good indicator of an autoimmune process. The presence of antibodies against hsp90 kD might be a much more specific indicator.