Immunological characterization of sural nerve biopsies from patients with Guillain-Barré syndrome.

Among eight sural nerve biopsies from patients with the Guillain-Barré syndrome (GBS), demyelination was observed in five and endoneural mononuclear cell infiltrates in three. Receptors for the activated third component of complement (C3b) were detected within the nerve fascicles. The receptor activity was reduced in five biopsies, and in vivo deposition of C3 within the endoneurium occurred in four. Immunoglobulins were found in four biopsies and appeared to be localized along the myelin sheaths. Both T and B lymphocytes could be detected in the mononuclear cell infiltrates, but the relative proportions of these cells could not be determined. Macrophages present in two biopsies were found to possess IgG Fc receptors. The results indicate that the complement receptors may play a role in the binding of complement-containing complexes in the nerve during the GBS disease process.