Detection of neural autoantibodies in dogs with non-infectious inflammatory central nervous system disorders

Abstract

BACKGROUND: Easily obtainable biomarkers for non-infectious, inflammatory central nervous system (CNS) disorders in dogs are lacking. HYPOTHESIS/OBJECTIVES: Dogs with non-infectious inflammatory CNS disorders might have specific neural autoantibodies in serum or cerebrospinal fluid (CSF), or both, discoverable by commercially available indirect immunofluorescence (IIF) assays. ANIMALS: Dogs (n = 23) with non-infectious inflammatory CNS disorders, including meningoencephalomyelitis of unknown origin, were recruited from the University Hospital for Companion Animals (Copenhagen, Denmark). METHODS: Using an exploratory, prospective study design, serum and CSF from dogs were investigated for specific neural autoantibodies with cell- and tissue-based IIF assays used to identify neural autoantibodies in humans. RESULTS: Astrocytic autoantibodies against glial fibrillary acidic protein were present in 2 dogs, neuronal targeted autoantibodies against N-methyl-D-aspartate receptors (NMDAR) in 2 dogs, and tripartite motif-containing protein 46 in 1 dog. Additionally, autoantibodies toward myelin were suspected in 6 dogs and myelin-oligodendrocyte glycoprotein in 4 dogs. Autoantibodies against a neuronal surface structure were suspected in 1 dog but could not be further specified. CONCLUSIONS AND CLINICAL IMPORTANCE: This study confirmed the presence of neural autoantibodies in several dogs with non-infectious inflammatory CNS disorders. The importance of both tissue- and cell-based assays (CBA) is emphasized by the fact that all specific autoantibodies apart from those targeting NMDAR were detected by tissue-based assays and then confirmed on cell-based assays (CBA).