Although the antibody-dependent cytotoxicity (ADCC) is the main patomechanism of GAD65Ab-dependent diabetes mellitus, so far the pathogenetic and prognostic role of GAD65Ab level in SPS has been unknown.8 Contrary to ADCC, the CNS autoantibodies to GAD may cause predominant functional impairment of GABA neurons (reversible injury). This evidence concerns the gene GAD1 and stiff-person syndrome.