Diagnostic Tests

CLINICAL ASSOCIATIONS

Mitogen’s IgLON5 Sleep Disorder Test is an autoimmune diagnostic test that helps determine if a sleep disorder is due to the presence of autoantibodies to IgLON5 – a cell membrane antigen that is an immunological target for specific autoantibodies. IgLON5 (immunoglobulin-like cell adhesion molecule 5) is a protein that acts as neuronal cell surface adhesion molecule with unknown function. It is, however, known that the IgLON protein family is involved in neuronal development and synaptic formation (ie. neurite sprouting and cell adhesion, astrocyte growth and limbic axonal differentiation), as well as cortical and hippocampal proliferation and synaptogenesis. Some scientists speculate that IgLONs play a role in the evolution of brain anatomy and complex maturation as well as influencing cellular migration and brain-blood barrier integrity.

The association of IgLON5-autoantibodies is strongly associated with sleep disorders from parasomnia to complete sleeplessness. The disorders occur both in the rapid-eye movement (REM) as well as in the non-REM sleep phases. The most frequent symptoms during these sleep dysfunctions are abnormal movement and behaviour, obstructive sleep apnoea, stridor, dysarthria, dysphagia, sleepwalking, ataxia and chorea.

Treatment Options: Immunotherapy treatments such as immunosuppressant, IV corticosteroid, IV immunoglobulins, Rituximab, Cyclophosphamide, Azathioprine and Mycophenolat Mofetil have been used and used in parallel leading to improved patient outcomes. Regardless, aggressive immunotherapy treatment is reported to be crucial for outcome, as untreated patients appear to have a higher mortality.

References:
Sabater L, Planaguma J, Dalmau J, Graus F. Cellular investigations with human antibodies associated with the anti-IgLON5 syndrome. J Neuroinflammation. (2016) 13:226. 10.1186/s12974-016-0689-1
Hashimoto T, Maekawa S, Miyata S. IgLON cell adhesion molecules regulate synaptogenesis in hippocampal neurons. Cell Biochem Funct. (2009) 27:496–8. 10.1002/cbf.1600
Kubick N, Brosamle D, Mickael ME. Molecular evolution and functional divergence of the IgLON family. Evol Bioinformatics Online. (2018) 14:1176934318775081. 10.1177/1176934318775081
Nissen MS, Blaabjerg M. Anti-IgLON5 Disease: A Case With 11-Year Clinical Course and Review of the Literature. Front Neurol. 2019; 10: 1056. Published online 2019 Oct 2. doi: 10.3389/fneur.2019.01056