Diagnostic value of anti-GM1 ganglioside serology and validation of the INCAT-ELISA

Abstract The Inflammatory Neuropathy and Treatment (INCAT) group developed a standardized ELISA method for the detection of serum anti-GM1 antibodies. The diagnostic value of anti-GM1 antibodies determined by this method has not yet been established in large groups of patients. We assessed the reproducibility, sources of variation, optimal cut-off values and evaluated the diagnostic relevance of the INCAT-ELISA in various groups of patients and controls ( N  = 1232). The coefficient of variance was 11.2% for IgM and 3.8% for IgG. High IgG titers were only found in Guillain–Barre syndrome (GBS) and other inflammatory polyneuropathies. High IgM titers were associated with GBS and multifocal motor neuropathy. Low IgM titers had no additional diagnostic value. The INCAT-ELISA is a reliable test with additional diagnostic value in specific clinical situations.