Is narcolepsy an autoimmune disease? According to researchers at the Stanford University School of Medicine in California narcolepsy—a chronic disorder where one’s brain can’t control sleep-wake cycles and involves random bouts of sleep and loss of voluntary muscle tone–is indeed an autoimmune disease. Narcolepsy researcher Emmanuel Mignot, immunologist Elizabeth Mellins and their collaborators had their research publicized in the current issue of the online magazine Science Translational Medicine.
Their study confirms a longstanding hypothesis and reveals that in people who are genetically susceptible, the chronic disease is caused by the loss of neurons that create the hormone hypocretin which keeps people awake. The research confirms that in these individuals “the immune system attacks healthy cells.”
Specifically, these individuals have a unique group of a type of immune cell named CD4+ T that targets hypocretin possibly because it is similar to the H1N1 “swine flu” virus. Mellins said: “Up till now, the idea that narcolepsy was an autoimmune disorder was a very compelling hypothesis, but this is the first direct evidence of autoimmunity. “I think these cells are a smoking gun.”
While it is uncertain why some individuals make these T cells and others don’t, genetics appears to play a part. In fact, prior studies, Mignot noted, have proven “that 98% of people with narcolepsy have a variant of the gene HLA” that is present in 25% of the general population.
Mellins also noted that infections are relevant as well adding that narcolepsy occurs when individuals with a genetic predisposition involving numerous narcolepsy-related gene variants come across “an environmental factor that mimics hypocretin” initiating a response from the immune system.
A neurologist at Harvard Medical School in Boston, Massachusetts, Thomas Scammell concludes the discovery is “one of the biggest things to happen in the narcolepsy field for some time.”
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