These review results were mixed on the use of immunotherapy to treat narcolepsy, with benefits typically being temporary.
The chronic sleep disorder narcolepsy is characterized by excessive daytime sleepiness (EDS), and studies show it can do extensive damage if not treated. It also is associated with cataplexy, the loss of muscle tone triggered by intense, usually positive, emotions while awake. Other symptoms include hallucination and sleep paralysis. Onset is typically within the first 2 decades of life, and up to 65% of cases happen before age 20.
It is considered a rare disorder, affecting just 1 of 2000 individuals, and there is no cure; current treatment is to address symptoms. Results of a recent review published in Nature and Science of Sleep—which highlights that the total incidence is 20 to 50 cases per 100,000 individuals worldwide—show that the condition might instead be an autoimmune disorder that could benefit from immunotherapy.
However, previous results on study in this area are mixed. More well known, the authors point out, is that patients with narcolepsy “have lower education and higher unemployment rates compared to the general population and present with higher frequency of other medical/psychiatric comorbidities and concurrent medication usage, and reduced rates of marriage/cohabitation.”
Their review covered supportive evidence for immunotherapy’s use in treating narcolepsy, outcomes, current issues, and future directions.
The evidence the authors found supporting a possible autoimmune-related role in the narcolepsy space are the following:
Previous research does show that HLA-DQB1*06:02 can increase the risk of narcolepsy, even more so in the presence of comorbid cataplexy.
In addition, immunotherapy use results were mixed:
Noting that a majority of the evidence they found on immunotherapy use in narcolepsy came from small, uncontrolled case studies with “different treatment schemes and highly heterogeneous outcome measures,” the investigators said current evidence does not support immunotherapy’s use for this disease state.
“Randomized controlled clinical trials are needed to provide substantial evidence and avoid bias related to placebo effect and to spontaneous disease improvements,” they noted. “No disease-modifying cure is available, calling for future research on treatment strategies as well as on diagnostic approaches able to identify patients who will develop NT1 among those complaining of only EDS.”
The time is ripe, they concluded, for randomized, double-blind, placebo-controlled trials into the use of immunotherapy in narcolepsy.
Maggie L. Shaw contributed to this article.
Giannoccaro MP, Liquori R, Plazzi G, Pizza F. Reviewing the clinical cmplications of treating narcolepsy as an autoimmune disorder. Nat Sci Sleep. 2021;13:557-577. doi:10.2147/NSS.S275931