Axonal neuropathy with monoclonal IgG kappa that binds to a neurofilament protein

We report a 74-year-old woman with a slowly progressive sensory motor axonal neuropathy and a monoclonal IgG-kappa that bound to a 68-kd axonal protein identified as the low molecular weight neurofilament protein. The sera of control subjects and disease controls did not bind to neurofilament protein.