Anti-ganglioside antibodies in patients with rheumatoid arthritis complicated by peripheral neuropathy

Gangliosides are a diverse class of glycolipids found in the plasma membrane of mammalian cells and are particularly abundant in cells of the nervous system. Serum antibodies to gangliosides have been detected in various neurological disorders with some evidence that they play a pathogenic role. In this study, we have investigated whether anti-ganglioside antibodies were elevated in a group of patients with rheumatoid arthritis (RA) who developed peripheral neuropathy (PN). An ELISA technique was used to test sera from 28 patients with RA and PN. 38 RA patients without PN and 20 normal controls for the presence of IgG and IgM anti-GM1 and sulphatide antibodies. The patients with RA and PN had higher pain scores (P < 0.005), more extra-articular features (P < 0.05), higher erosive scores (P < 0.0001), lower haemoglobin (P < 0.005), higher ESR (P < 0.001) and were more often on disease-modifying drugs (P < 0.05). Twelve RA patients with PN (43%), but only two RA controls (5%), had positive titres against one or more gangliosides (P < 0.001). The neurologic disability score (NDS) correlated with RA duration (P < 0.05), and with levels of IgM anti-GM1 (P < 0.001) and IgM anti-sulphatide (P < 0.05) antibodies. We conclude that PN is more common in patients with severe rheumatoid disease, and a significant proportion have elevated levels of anti-ganglioside antibodies.