Schmidt-Lanterman's incisures--the principal target of autoimmune attack in demyelinating Guillain-Barré syndrome?

We used immunocytochemical staining of peripheral (trigeminal) nerve to screen sera of patients with Guillain-Barré syndrome (GBS) for the presence of autoantibodies, using sera from patients with other neurological diseases and healthy volunteers as controls. Most sera mildly reacted with axons, myelin sheaths, or sensory neurons without correlation to a specific disease. A characteristic staining, however, was found in 23 demyelinating cases (89%) out of 26 investigated GBS sera. With these sera, dark, oval and often paired small blobs were observed throughout the sections. A similar picture was rarely observed with sera from patients with other disorders or healthy controls. Using immunocytochemical marker proteins and high light microscopic resolution, the blobs were identified as Schmidt-Lanterman's incisures (SLIs). Further investigations will be necessary to identify the corresponding antigen and to answer the question, whether these antibodies represent an epiphenomenon or play a role in the causative mechanism of the disease.