IgG reactivity in the spinal cord and motor cortex in amyotrophic lateral sclerosis
J. I. Engelhardt and S. H. Appel
Department of Neurology, Baylor College of Medicine, Houston, Tex. 77030.
The spinal cord and motor cortex of patients with amyotrophic lateral
sclerosis (ALS) were examined with immunohistochemical methods for the
presence of IgG. In 13 of 15 spinal cords, a population of motoneurons
stained positively for IgG in a granular pattern, characteristic of binding
to the rough endoplasmic reticulum. In 6 of 11 motor cortices, a proportion
of pyramidal cells also stained positively for IgG. No such reactivity was
noted in motoneurons of control human tissues, although positive IgG
staining was present in astrocytes of ALS and control specimens. Reactive
microglia and/or macrophages were detected in the territory of degenerating
pyramidal tracts and ventral horns. The surface of most of these cells
stained positively for IgG, and 50% stained positively for HLA-DR. The
accumulation of IgG in motoneurons and the presence of immunologically
active macrophages provide additional evidence for the participation of
immunologic factors in the pathogenesis of ALS.
