Identification of light chain type bands in CSF and serum oligoclonal IgG from patients with multiple sclerosis

The light (L) chain types (kappa and lambda) of oligoclonal IgG bands of matching CSF and serum from 10 MS patients were identified in immunofixation after isoelectric focusing in polyacrylamide gel. Each specimen showed 10-15 oligoclonal bands in pH region of 7.5-9.3. In 7 MS CSF and 5 sera a greater number of oligoclonal IgG bands were of kappa (kappa)-type whereas in 3 CSF and 2 sera the majority was of lambda (lambda)-type. In 3 sera a clearcut correlation of bands with either type of L chain was not observed due to diffuse staining background. Only a small number of oligoclonal IgG bands in 7 of 10 CSF and serum pairs had identical isoelectric points and the same type of L chain. The results show that the individual MS patient had oligoclonal IgG bands in serum, differ with respect to number, isoelectric point and L chain type from the oligoclonal IgG profile seen in the patient's CSF.