Glycine receptor antibody — a marker for NMO/ NON-MS demyelination?

BackgroundAntibodies against glycine receptors (GlyR Ab) have been strongly linked to progressive encephalomyelitis with rigidity and myoclonus (PERM). Their association with other neurological disorders is poorly understood.MethodsWe looked retrospectively at all patients who were tested for (GlyR Abs) in the Walton Centre between 2010–2014.Results138 patients were tested. The pre-test diagnoses (n) were transverse myelitis (34), NMO (22, (7 AQP4 IgG+ve and 15 AQP4 IgG-ve), optic neuritis (17), MS (22), ADEM (4), other atypical demyelination (4), encephalitis (11), epilepsy (4), dementia (4), parkinsonism (3), functional disorders (3) and others (10). 53.6% (74) had a relapsing course6/138 (4%) were positive for GlyR Ab. The diagnoses (n) were optic neuritis (2) one of which was AQP4 IgG+ve, NMO-AQP4-IgG negative (1), transverse myelitis (1), tumefactive demyelination (1) and undiagnosed spastic ataxic syndrome with normal imaging (1). 5/6 had a relapsing course and are on immunosuppressants.ConclusionAntibodies against GlyR are not common and seem to be associated with some non-PERM inflammatory CNS diseases, with a relapsing course. Larger studies are required to understand the clinical and prognostic significance of these early findings.