Causes of Death in Anti-IgLON5 Disease: A Novel Case Report and Systematic Literature Review

BACKGROUND/OBJECTIVES: Anti-IgLON5 disease is a neurological disorder characterized by the presence of autoantibodies directed against the neuronal cell adhesion protein IgLON5. Pathophysiology involves both autoimmune inflammation and neurodegenerative processes. The most common causes of death are sudden death, central hypoventilation, dysphagia, and aspiration. However, the high rate of largely unclear sudden deaths calls for further research in this area.

METHODS: We performed a systematic search of the literature on causes of death in anti-IgLON5 disease following the PRISMA guidelines. In addition, we present a new case that was followed up in our clinic until death.

RESULTS: Of 258 publications with anti-IgLON5 disease, 21 publications comprising 61 cases that reported the causes of death were included in the analysis. The most common cause of death was death due to complications at 36.1%, followed by sudden death, accounting for 32.8% of the cases. Other causes include respiratory, cardiac, and unknown causes. The patient presented here as a case report was also diagnosed with cardiac amyloidosis and died from a cardiac cause of sudden death.

CONCLUSIONS: Sudden death in anti-IgLON5 disease is one of the most common causes of death in the literature. A progressive neurodegenerative process in the brain stem causing central hypoventilation is generally assumed as a major causative factor. The case reported here had concomitant cardiac amyloidosis, which may raise the question as to whether unrecognized cardiac causes, which are not routinely screened for in this population, might represent another cause of sudden death, which would have important therapeutic implications.