Combined analyses of proteins in serum and CSF samples from patients with nervous and mental diseases were performed by an improved procedure. In one study, examples are presented that aid diagnosis of neurologic diseases (1). In a second study of patients with schizophrenia, the results revealed differences among these patients in the blood-brain barrier permeability and endogenous IgG production. These findings reflect differing underlying biological mechanisms which are under further investigation (2). In a third study of patients with post-poliomyelitis muscular atrophy, oligoclonal immunoglobulins were found in the majority of these patients indicating the possibility of an antibody response directed against viral or neuronal proteins (3). In a fourth study, cryoglobulins were isolated from serum samples of patients with rheumatoid arthritis (RA), systemic Lupus erythematosus (SLE) and Sjogren's syndrome (SS). The examination of the cryoglobulins from these patients revealed that they were mixed polyclonal in RA and SLE and mixed monoclonal in SS. These findings suggest that in SS a monoclonal B-cell process exists which may lead to monoclonal lymphoid hyperplasia (4).
