Reviewing the Clinical Implications of Treating Narcolepsy as an Autoimmune Disorder

Abstract

Narcolepsy type 1 (NT1) is a lifelong sleep disorder, primarily characterized clinically by excessive daytime sleepiness and cataplexy and pathologically by the loss of hypocretinergic neurons in the lateral hypothalamus. Despite being a rare disorder, the NT1-related burden for patients and society is relevant due to the early onset and chronic nature of this condition. Although the etiology of narcolepsy is still unknown, mounting evidence supports a central role of autoimmunity. To date, no cure is available for this disorder and current treatment is symptomatic. Based on the hypothesis of the autoimmune etiology of this disease, immunotherapy could possibly represent a valid therapeutic option. However, contrasting and limited results have been provided so far. This review discusses the evidence supporting the use of immunotherapy in narcolepsy, the outcomes obtained so far, current issues and future directions.

Keywords: immunomodulation; immunotherapy; intravenous immunoglobulin; monoclonal antibodies; narcolepsy type 1; steroid.

Figure 1

Outcomes of IVIG treatment in children and adults NT1 patients. The graphs show the individual patients outcome assessment values at baseline and after each IVIG infusion. Each line represents a single individual, numbered according to the case numbers in Table 2. No significant variations were observed in the majority of cases in respects to cataplexy frequency (A), sleep latency at the multiple sleep latency test (MSLT) (B) or Epworth sleepiness scale (ESS) scores (C) in children and adults.