ISOELECTRIC-FOCUSING IN AN IMMOBILIZED PH GRADIENT FOR THE DETECTION OF INTRATHECAL IGG IN CEREBROSPINAL-FLUID - SENSITIVITY AND SPECIFICITY FOR THE DIAGNOSIS OF MULTIPLE-SCLEROSIS

Cerebrospinal fluid and serum from 192 patients was analysed for the p resence of intrathecally synthesized oligoclonal IgG bands using isoel ectric focusing in an immobilized pH gradient pH 7- 10. The sensitivit y of this method for the diagnosis of multiple sclerosis (MS) was 95% (21 of 22), or 75% if patients with suspected MS were included. The sp ecificity for the diagnosis of MS was 98%, or 96% if the suspected MS patients were included. The very high specificity may be because the i ntrathecally synthesized oligoclonal IgG associated with MS is more al kaline than IgG from serum and is better detected in an immobilized al kaline pH gradient.