Immunofixation superior to plasma agarose electrophoresis in detecting small M-components in patients with polyneuropathy.

Abstract

Monoclonal immunoglobulins (M-components) in blood are found in some patients with polyneuropathy and are thought to be of pathogenetic importance, especially if the M-component is of IgM isotype. As the finding of an M-component may indicate a treatable polyneuropathy, the potential of the method to uncover an M-component is of importance. Cellulose acetate or agarose electrophoresis used in routine practice may miss small M-components covered by other proteins. We therefore applied the uncovering and specific method of immunofixation in comparison with agarose electrophoresis on patients investigated for polyneuropathy. Of 83 consecutive patients, 5 had M-components. Two of these 5 patients, one with an axonal polyneuropathy and the other with a lower motor neuron syndrome, had extra bands on agarose electrophoresis, verified as IgG M-components by immunofixation. In the 3 additional patients an M-component was uncovered only by immunofixation, not seen in the agarose electrophoresis of plasma; 2 of them were of IgM isotype and one was of IgG isotype. These 3 patients were diagnosed as having a demyelinating (i.e., possibly immune-mediated) polyneuropathy by means of neurophysiology and in one by means of nerve biopsy. A 6th patient had 2 small bands in the gamma region on the agarose electrophoresis, verified as oligoclonal bands of IgG isotype by immunofixation but was not judged as an M-component. Three out of the 83 patients, were judged as having motor neuron diseases. All remaining 80 were found to have polyneuropathy.(ABSTRACT TRUNCATED AT 250 WORDS)

• Authors: M Vrethem, B Larsson, H von Schenck, J Ernerudh
• Journal: Journal of the neurological sciences (J Neurol Sci) Vol. 120 Issue 1 Pg. 93-8 (Dec 01 1993) ISSN: 0022-510X [Print] Netherlands
• PMID: 8289086 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Immunoglobulin A
• Immunoglobulin G
• Immunoglobulin M

Topics

• Adult
• Aged
• Aged, 80 and over
• Electrophoresis, Agar Gel (methods)
• Female
• Humans
• Immunoglobulin A (blood)
• Immunoglobulin G (blood)
• Immunoglobulin M (blood)
• Male
• Middle Aged
• Motor Neuron Disease (blood, immunology)
• Nervous System Diseases (blood, etiology, immunology)
• Reference Values
• Sensitivity and Specificity