Cryoglobulins as indicators of upregulated immune response in schizophrenia

Objective: In the present work the concentration of abnormal immune complexes, cryoglobulins (Cgs), in the blood of schizophrenic patients was determined, and immunochemical composition of these complexes was studied. Patients and methods: Eighty multiple-episode schizophrenia-affected subjects (55 medicated, 25 drug-free) and 40 healthy controls were involved in the study. Cgs were isolated by exposure of blood serum samples to precipitation at low temperature followed by extensive washings of Cg-enriched pellets. The immunochemical composition of Cgs was analyzed using different electrophoretic and immunoblotting systems. Results: Significantly increased blood serum levels of type III Cgs were detected in all schizophrenia-affected subjects, as compared to controls. We also revealed the presence of C1q and C3 complement proteins and their activation products in Cgs isolated from the blood of schizophrenic patients. Conclusions: The results of the present study suggest that Cgs are involved in schizophrenia-associated upregulated immune response by binding the complement proteins, activating the complement cascade and triggering aberrant apoptosis. (c) 2007 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.