Glycine receptor antibodies and coeliac disease-related neurological dysfunction

Gluten sensitivity can manifest with a spectrum of neurological dysfunction including ataxia, encephalopathy and neuropathy with or without associated coeliac disease (CD). Gluten sensitivity can also present with central nervous system (CNS) hyperexcitability and cortical myoclonus which is often accompanied with refractory CD. CNS hyperexcitability can also be associated with Glutamic Acid Decarboxylase (GAD) antibodies or much less commonly with Glycine Receptor Antibodies (GlyR-Abs) but the direct pathogenic roles of these antibodies remain debatable. We have previously reported a link between gluten sensitivity and anti-GAD associated ataxia which improves with the adoption of gluten-free diet. It is unclear if a similar link exists between gluten driven CNS hyperexcitability and the presence of GlyR-Abs. We report two cases of CD presenting with CNS hyperexcitability and associated GlyR-Abs. Apart from ataxia and cortical myoclonus, one patient had refractory CD and died from enteropathy-associated T-cell lymphoma. The other patient not only improved with strict gluten-free diet but also showed serological elimination of circulating GlyR-Abs. We conclude that there is an interaction between gluten sensitivity and GlyR-Abs-associated CNS hyperexcitability and in such patients gluten-free diet is an important therapeutic intervention. The elimination of GlyR-Abs by the adoption of gluten free diet suggests that these antibodies may represent an epiphenomenon rather than being directly implicated in the pathogenesis.