New autoantibodies in neurological diseases

Introduction The spectrum of antibodies against neural tissues detected by indirect immunofluorescence (IIF) has expanded rapidly. There are now approximately 20 anti-neuronal antibodies (PNAs) detected in association with neurological diseases, especially with underlying malignancies. Many PNAs have been correlated with disease and neurological defects and appear to fall into two groups: those that are cytotoxic (PCA-1 and ANNA-1); and others that are inhibitory (anti-NMDAR, anti-VGCC and anti-VGKC). We present a series of novel antibodies that stain a variety of CNS structures in patients with diverse neurological presentations. Patients and Methods All patients in this study were referred for either anti-neuronal, anti-NMO-IgG (neuromyelitis optica) or anti-NMDAR (N-methyl-D-aspartate receptor) antibody testing. Discussion With the introduction of NMO-IgG IIF testing in 2007 and anti-NMDAR testing in 2010, 4377 patients with increasingly diverse neurological and psychiatric presentations were tested. We have now identified several cohorts of patients with a variety of anti-CNS antibodies targeting (1) cerebellar white matter fibres, (2) glia, (3) axons, and (4) astrocytes. Although the targets for these antibodies appear to be hetero-genous, several patients have staining patterns in common and the pattern of tissue staining often correlates with the clinical presentation. We are undertaking further studies to identify the precise nature of the target antigens.