1 Department of Laboratory Medicine and Pathology (N.A., A.G., V.A.L., S.H., A.M., S.J.P.), Department of Neurology (V.A.L., A.M., S.J.P.), and Department of Immunology (V.A.L.), Mayo Clinic, Rochester, MN; and Institute for Experimental Immunology (L.K., M.S.), Affiliated to Euroimmun AG, Luebeck, Germany.