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September 1969

Recurrent Encephalopathy: Associated With Low Molecular Weight γM in the Serum and Cerebrospinal Fluid

Author Affiliations

Bethesda, Md
From the Medical Neurology Branch, National Institutes of Neurological Diseases and Stroke (Drs. Griggs and McFarlin), and the Metabolism Branch, National Cancer Institute (Dr. Strober), National Institutes of Health, Bethesda, Md.

Arch Neurol. 1969;21(3):303-314. doi:10.1001/archneur.1969.00480150093012

IMMUNOGLOBULIN M, γM, is not detectable by immunoprecipitation techniques in normal cerebrospinal fluid (CSF).1 In early studies, this immunoglobulin was shown to be a macroglobulin with a sedimentation coefficient of 19S.2,3 In recent studies,3-13 however, smaller proteins with antigenic determinants identical with the heavy chain (μ) of 19S-γM (HMW-γM) have been demonstrated. These lower molecular weight forms of γM (LMW-γM) occur in patients with a variety of disorders including systemic lupus erythematosus (SLE),6,7 ataxia-telangiectasia,7 antibody deficincy syndromes,5,7,12,13, malignancy of the plasma-cell-lymphatic system,10 and as an M protein in a lymphomatous disorder.9 Some LMW-γM proteins have been shown to have antinuclear and incomplete isohemagglutinin activity.7 To date, LMW-γM has not been demonstrated in the CSF.

This report presents a case characterized clinically by recurrent central nervous system (CNS) symptoms and skin findings typical of SLE, in whom LMW-γM was found in