Abnormal CSF immunoglobulin components detected by isoelectric focusing.

The results from thin-layer isoelectric focusing of 4000 paired CSF and serum samples were examined for the occurrence of abnormal CSF immunoglobulin components. Such changes, not referable to serum protein abnormalities, were detected in 630 samples from 465 patients. All but 3 of these subjects had symptoms and signs of an affection of the nervous system, predominantly MS and encephalitic or myelitic/radiculitic disorders of known or presumed infectious etiology. The abnormal, microheterogeneous immunoglobulin components were mostly focused in the pI range approximately 7.5--9 with generally a shift towards pI-values > 8 pH units; a distribution differing from that of M components in plasma cell dyscrasias.