Isoelectric focusing of CSF and serum proteins in neurological disorders combined with benign and malignant proliferations of reticulocytes, lymphocytes and plasmocytes.

The clinical data and the CSF and serum findings on isoelectric focusing (IEF) and electrophoresis were studied in nine patients with neurological disorders combined with proliferations of reticulocytes, lymphocytes or plasmocytes. Paraneoplastic neurological manifestations were considered in some of the subjects. CSF findings compatible with intrathecal synthesis of oligoclonal immunoglobulins were observed in two patients with lymphoreticular neoplasms. One of these had an IEF band spectrum differing from those found with multiple sclerosis (MS), while the other had changes indistingusihable from those with MS. On IEF the CSF and serum M components of the patients with plasma cell dyscrasias, as well as the serum M components of nine other patients with myelomatosis, exhibited considerable microheterogeneity with 3-18 abnormal bands. The isoelectric point (pI) of the individual bands was 5.8-9.2, mostly greater than 6.4; the band spectra exhibited pI ranges of 0.4-2.5 pH units, most frequently 0.4-1.2. The CSF findings, possible modified by the blood-CSF barrier, reflected the serum changes of plasma cell dyscrasias. The immunoglobulins produced in such disorders gave IEF band spectra differing from those of intrathecally produced immunoglobulins in MS.