Simultaneous Determination of Cerebrospinal Fluid Oligoclonal Bands and the “y-Protein Index ” by Agarose Electrophoresis and Densitometry

cerebrospinal fluid, and the “y-protein index ” was concurrent-ly calculated from the same strip. For the index, an upper limit of normal of 0.66 was established. We compared results with the clinical diagnosis in 69 patients with multiple sclerosis and 48 control patients with other diseases. Sensitivity, specificity, and positive predictive values of 73%, 96%, and 96%, respectively, were obtained from the index. An abnor-mal index and the presence of oligoclonal bands combined Increased the positive predictive value to 100%. This ap-proach may allow adequate qualitative and quantitative as-sessment of gamma-globulin abnormalities in cerebrospinal fluid after a single laboratory procedure. AddItional K.yphraees: multiple sclerosis gamma-globulin ab-normalities In multiple sclerosis (MS) a key finding is increase