Narcolepsy Type 1 Patients Research Articles

Enhanced influenza A H1N1 T cell epitope recognition and cross-reactivity to protein-O-mannosyltransferase 1 in Pandemrix-associated narcolepsy type 1

Narcolepsy type 1 (NT1) is a chronic neurological disorder having a strong association with HLA-DQB1*0602, thereby suggesting an immunological origin. Increased risk of NT1 has been reported among children or adolescents vaccinated with AS03 adjuvant-supplemented pandemic H1N1 influenza A vaccine, Pandemrix. Here we show that pediatric Pandemrix-associated NT1 patients have enhanced T-cell immunity against the viral epitopes, neuraminidase 175–189 (NA175–189) and nucleoprotein 214–228 (NP214–228), but also respond to a NA175–189-mimic, brain self-epitope, protein-O-mannosyltransferase 1 (POMT1675–689). A pathogenic role of influenza virus-specific T-cells and T-cell cross-reactivity in NT1 are supported by the up-regulation of IFN-γ, perforin 1 and granzyme B, and by the converging selection of T-cell receptor TRAV10/TRAJ17 and TRAV10/TRAJ24 clonotypes, in response to stimulation either with peptide NA175–189 or POMT1675–689. Moreover, anti-POMT1 serum autoantibodies are increased in Pandemrix-vaccinated children or adolescents. These results thus identify POMT1 as a potential autoantigen recognized by T- and B-cells in NT1.

A/H1N1 hemagglutinin antibodies show comparable affinity in vaccine-related Narcolepsy type 1 and control and are unlikely to contribute to pathogenesis

An increased incidence of narcolepsy type 1 (NT1) was observed in Scandinavia following the 2009–2010 influenza Pandemrix vaccination. The association between NT1 and HLA-DQB1*06:02:01 supported the view of the vaccine as an etiological agent. A/H1N1 hemagglutinin (HA) is the main antigenic determinant of the host neutralization antibody response. Using two different immunoassays, the Luciferase Immunoprecipitation System (LIPS) and Radiobinding Assay (RBA), we investigated HA antibody levels and affinity in an exploratory and in a confirmatory cohort of Swedish NT1 patients and healthy controls vaccinated with Pandemrix. HA antibodies were increased in NT1 patients compared to controls in the exploratory (LIPS p = 0.0295, RBA p = 0.0369) but not in the confirmatory cohort (LIPS p = 0.55, RBA p = 0.625). HA antibody affinity, assessed by competition with Pandemrix vaccine, was comparable between patients and controls (LIPS: 48 vs. 39 ng/ml, p = 0.81; RBA: 472 vs. 491 ng/ml, p = 0.65). The LIPS assay also detected higher HA antibody titres as associated with HLA-DQB1*06:02:01 (p = 0.02). Our study shows that following Pandemrix vaccination, HA antibodies levels and affinity were comparable NT1 patients and controls and suggests that HA antibodies are unlikely to play a role in NT1 pathogenesis.

Autonomic mechanisms of blood pressure alterations during sleep in orexin/hypocretin-deficient narcoleptic mice.

Increase in arterial pressure (AP) during sleep and smaller differences in AP between sleep and wakefulness have been reported in orexin (hypocretin)-deficient mouse models of narcolepsy type 1 (NT1) and confirmed in NT1 patients. We tested whether these alterations are mediated by parasympathetic or sympathetic control of the heart and/or resistance vessels in an orexin-deficient mouse model of NT1. Thirteen orexin knock-out (ORX-KO) mice were compared with 12 congenic wild-type (WT) mice. The electroencephalogram, electromyogram, and AP of the mice were recorded in the light (rest) period during intraperitoneal infusion of atropine methyl nitrate, atenolol, or prazosin to block muscarinic cholinergic, β 1-adrenergic, or α 1-adrenergic receptors, respectively, while saline was infused as control. AP significantly depended on a three-way interaction among the mouse group (ORX-KO vs WT), the wake-sleep state, and the drug or vehicle infused. During the control vehicle infusion, ORX-KO had significantly higher AP values during REM sleep, smaller decreases in AP from wakefulness to either non-rapid-eye-movement (non-REM) sleep or REM sleep, and greater increases in AP from non-REM sleep to REM sleep compared to WT. These differences remained significant with atropine methyl nitrate, whereas they were abolished by prazosin and, except for the smaller AP decrease from wakefulness to REM sleep in ORX-KO, also by atenolol. Sleep-related alterations of AP due to orexin deficiency significantly depend on alterations in cardiovascular sympathetic control in a mouse model of NT1.

Cerebrospinal fluid monoamine levels in central disorders of hypersomnolence.

Whether the cause of daytime sleepiness in narcolepsy type 1 (NT1) is a direct consequence of the loss of orexin (ORX) neurons or whether low orexin reduces the efficacy of the monoaminergic systems to promote wakefulness is unclear. The neurobiology underlying sleepiness in other central hypersomnolence disorders, narcolepsy type 2 (NT2), and idiopathic hypersomnia (IH), is currently unknown. Eleven biogenic amines including the monoaminergic neurotransmitters and their metabolites and five trace amines were measured in the cerebrospinal fluid (CSF) of 94 drug-free subjects evaluated at the French National Reference Center for Narcolepsy: 39 NT1(orexin-deficient) patients, 31 patients with objective sleepiness non orexin-deficient (NT2 and IH), and 24 patients without objective sleepiness. Three trace amines were undetectable in the sample: tryptamine, octopamine, and 3-iodothyronamine. No significant differences were found among the three groups for quantified monoamines and their metabolites in crude and adjusted models; however, CSF 5-hydroxyindoleacetic acid (5-HIAA) levels tended to increase in NT1 compared to other patients after adjustment. Most of the biomarkers were not associated with ORX-A levels, clinical or neurophysiological parameters, but a few biomarkers (e.g. 3-methoxy-4-hydroxyphenylglycol and norepinephrine) correlated with daytime sleepiness and high rapid eye movement (REM) sleep propensity. We found no striking differences among CSF monoamines, their metabolites and trace amine levels, and few associations between them and key clinical or neurophysiological parameters in NT1, NT2/IH, and patients without objective sleepiness. Although mostly negative, these findings are a significant contribution to our understanding of the neurobiology of hypersomnolence in these disorders that remain mysterious and deserve further exploration.

Chapter 12 - Narcolepsy Type I as an autoimmune disorder

Narcolepsy Type 1 (NT1) is hypothesized to be an autoimmune disease targeting the hypocretin/orexin neurons in the lateral hypothalamus. Ample genetic and epidemiologic evidence point in the direction of a pathogenesis involving the immune system. Many autoantibodies have been detected in blood samples from NT1 patients, but none in a consistent manner. Importantly, T cells directed toward hypocretin/orexin neurons have been detected in samples from NT1 patients. However, it remains to be seen if these potentially autoreactive T cells are also present in the hypothalamus and if they are pathogenic. For this reason, NT1 does still not fully meet the criteria for being classified as a genuine autoimmune disease, even though more and more results are pointing in that direction as will be described in this chapter. The autoimmune hypothesis has led to many attempts at slowing or stopping disease progression with immunomodulatory treatment, but so far the overall results have not been very encouraging. It is clear that more research into the pathogenesis of NT1 is needed to establish the precise role of the immune system in disease development.

Hypothalamus and amygdala functional connectivity at rest in narcolepsy type 1

Introductionfunctional and structural MRI studies suggest that the orexin (hypocretin) deficiency in the dorso-lateral hypothalamus of narcoleptic patients would influence both brain metabolism and perfusion and would cause reduction in cortical grey matter. Previous fMRI studies have mainly focused on cerebral functioning during emotional processing. The aim of the present study was to explore the hemodynamic behaviour of spontaneous BOLD fluctuation at rest in patients with Narcolepsy type 1 (NT1) close to disease onset. MethodsFifteen drug naïve children/adolescents with NT1 (9 males; mean age 11.7 ± 3 years) and fifteen healthy children/adolescents (9 males; mean age 12.4 ± 2.8 years) participated in an EEG-fMRI study in order to investigate the resting-state functional connectivity of hypothalamus and amygdala. Functional images were acquired on a 3 T system. Seed-based functional connectivity analyses were performed using SPM12. Regions of Interest were the lateral hypothalamus and the amygdala. Resultscompared to controls, NT1 patients showed decreased functional connectivity between the lateral hypothalamus and the left superior parietal lobule, the hippocampus and the parahippocampal gyrus. Decreased functional connectivity was detected between the amygdala and the post-central gyrus and several occipital regions, whereas it was increased between the amygdala and the inferior frontal gyrus, claustrum, insula, and putamen. Conclusionin NT1 patients the abnormal connectivity between the hypothalamus and brain regions involved in memory consolidation during sleep, such as the hippocampus, may be linked to the loss of orexin containing neurons in the dorsolateral hypothalamus. Moreover, also functional connectivity of the amygdala seems to be influenced by the loss of orexin-containing neurons. Therefore, we can hypothesize that dysfunctional interactions between regions subserving the maintenance of arousal, memory and emotional processing may contribute to the main symptom of narcolepsy.

Impact of COVID-19 pandemic lockdown on narcolepsy type 1 management.

Study ObjectivesNarcolepsy type 1 (NT1) is a chronic rare hypersomnia of central origin requiring a combination of behavioral and pharmacological treatments. During the coronavirus disease 2019 (COVID‐19) pandemic, in Italy the population was forced into a lockdown. With this study, we aimed to describe the lockdown impact on NT1 symptom management, according to different patients' working schedule.MethodsIn the period between 10 April and 15 May 2020, we performed routine follow‐up visits by telephone (as recommended during the COVID‐19 emergency) to 50 patients >18 years old (40% males) under stable long‐term treatment. We divided patients into three groups: unchanged working schedule, forced working/studying at home, and those who lost their job (“lost occupation”). Current sleep–wake habit and symptom severity were compared with prelockdown assessment (six months before) in the three patient groups.ResultsAt assessment, 20, 22, and eight patients belonged to the unchanged, working/studying at home, and lost occupation groups, respectively. While in the lost occupation group, there were no significant differences compared with prepandemic assessment, the patients with unchanged schedules reported more nocturnal awakenings, and NT1 patients working/studying at home showed an extension of nocturnal sleep time, more frequent daytime napping, improvement of daytime sleepiness, and a significant increase in their body mass index. Sleep‐related paralysis/hallucinations, automatic behaviors, cataplexy, and disturbed nocturnal sleep did not differ.ConclusionsNarcolepsy type 1 patients working/studying at home intensified behavioral interventions (increased nocturnal sleep time and daytime napping) and ameliorated daytime sleepiness despite presenting with a slight, but significant, increase of weight.

Dream Generation and Recall in Daytime NREM Sleep of Patients With Narcolepsy Type 1.

The less rigid architecture of sleep in patients with narcolepsy type 1 (NT1) compared with healthy subjects may provide new insights into some unresolved issues of dream experience (DE), under the assumption that their DE frequencies are comparable. The multiple transition from wakefulness to REM sleep (sleep onset REM period: SOREMP) during the five trials of the Multiple Sleep Latency Test (MSLT) appears of particular interest. In MSLT studies, NT1 patients reported a DE after about 80% of SOREMP naps (as often as after nighttime REM sleep of themselves and healthy subjects), but only after about 30% of NREM naps compared to 60% of daytime and nighttime NREM sleep of healthy subjects. To estimate accurately the “real” DE frequency, we asked participants to report DE (“dream”) after each MSLT nap and, in case of failure, to specify if they were unable to retrieve any content (“white dream”) or DE did not occur (“no-dream”). The proportions of dreams, white dreams, and no dreams and the indicators of structural organization of DEs reported after NREM naps by 17 adult NT1 patients were compared with those reported by 25 subjects with subjective complaints of excessive daytime sleepiness (sc-EDS), who take multiple daytime NREM naps. Findings were consistent with the hypothesis of a failure in recall after awakening rather than in generation during sleep: white dreams were more frequent in NT1 patients than in sc-EDS subjects (42.86 vs 17.64%), while their frequency of dreams plus white dreams were similar (67.86 and 61.78%) and comparable with that of NREM-DEs in healthy subjects. The longer and more complex NREM-DEs of NT1 patients compared with sc-EDS subjects suggest that the difficulty in DE reporting depends on their negative attitude toward recall of contents less vivid and bizarre than those they usually retrieve after daytime SOREMP and nighttime REM sleep. As this attitude may be reversed by some recall training before MSLT, collecting wider amounts of DE reports after NREM naps would cast light on both the across-stage continuity in the functioning of cognitive processes underlying DE and the difference in content and structural organization of SOREM-DEs preceded by N1 or also N2 sleep.

Comparison of modafinil and pitolisant in narcolepsy: a non-inferiority meta-analytical approach.

AimTo assess the non-inferiority of pitolisant, a new compound for the relief of excessive daytime sleepiness (EDS) and cataplexy in narcolepsy, compared with modafinil.MethodsRandomized controlled trials (RCTs) in narcolepsy were searched systematically. Network meta-analysis (NMA) compared the efficacy and safety of pitolisant and modafinil. The main endpoints are Epworth Sleepiness Scale (ESS), Maintenance of Wakefulness Test (MWT), the number of cataplexies, and overall safety.ResultsOf 312 articles after removing duplicates, 10 RCTs were eligible for NMA. For ESS, a non-significant superior beneficial decrease (−0.69, [−2.18, 0.79]) showed non-inferiority of pitolisant (non-inferiority margin [NIM]=1, p=0.015). An MWT beneficial increase (2.12 minutes [−0.95, 5.19]; p=0.18) showed non-inferiority of pitolisant (NIM=−1). For cataplexy, the mean beneficial effect of pitolisant was significant, providing evidence of pitolisant superiority in addition to non-inferiority. The risk ratio (RR) of treatment-suspected adverse events for pitolisant/modafinil was 0.86 [0.44, 1.24] favoring pitolisant, confirming non-inferiority considering a safety margin of RR=1.25 (tolerance of 25%).ConclusionsPitolisant is non-inferior to modafinil in relieving EDS, but superior to modafinil in reducing cataplexy, outranking modafinil in narcolepsy type-1 patients. Despite a slight superiority of pitolisant in EDS relief, both drugs perform equally in narcolepsy type-2 patients.

CSF Levels of the Endocannabinoid Anandamide are Reduced in Patients with Untreated Narcolepsy Type 1: A Pilot Study.

Endocannabinoids (ECs) modulate both excitatory and inhibitory components in the CNS. There is a growing body of evidence that shows ECs influence both hypothalamic orexinergic and histaminergic neurons involved in narcolepsy physiopathology. Therefore, ECs may influence sleep and sleep-wake cycle. To evaluate EC levels in the CSF of untreated narcoleptic patients to test whether ECs are dysregulated in Narcolepsy Type 1 (NT1) and Type 2 (NT2). We compared CSF Anandamide (AEA), 2-Arachidonoylglycerol (2-AG) and orexin in narcoleptic drug-naïve patients and in a sample of healthy subjects. We compared NT1 (n=6), NT2 (n=6), and healthy controls (n=6). We found significantly reduced AEA levels in NT1 patients compared to both NT2 and controls. No differences were found between AEA levels in NT2 versus controls and between 2-AG levels in all groups, although a trend toward a decrease in NT1 was evident. Finally, the CSF AEA level was related to CSF orexin levels in all subjects. We demonstrated that the EC system is dysregulated in NT1.

0755 Pitolisant (Wakix) is an Effective Anti-Cataplexy Agent in Narcolepsy Type 1

Abstract Introduction Harmony Biosciences initiated the Pitolisant Expanded Access Clinical Evaluation (PEACE) program to allow treatment with pitolisant in adult patients with narcolepsy while pitolisant was an investigational medication in the United States. Starting in March 2019, Comprehensive Sleep Medicine Associates (CSMA) offered enrollment to patients who met the inclusion/exclusion criteria and who were deemed appropriate based on clinical judgment. All patients who enrolled were taking at least one standard-of-care agent for narcolepsy at enrollment. Many of the enrolled patients had refractory/challenging cases of narcolepsy. On August 14, 2019, Wakix received FDA approval for the treatment of excessive daytime sleepiness in adult patients with narcolepsy, which contrasts with the European label that states that Wakix is indicated for the treatment of narcolepsy in adults with or without cataplexy. Methods CSMA enrolled 21 patients in the PEACE program. The charts for all 10 narcolepsy type 1 (NT1) patients were reviewed. The 2 patients who did not have follow up after starting pitolisant were excluded. Results Of the 8 NT1 patients who had at least one follow up visit after initiating pitolisant, 6 reported substantial improvement or complete resolution of cataplexy compared to baseline. For example, one patient’s wife stated, “I forgot my husband was funny because he would avoid telling jokes until he started pitolisant.” Another stated, “I have not had an episode of cataplexy since starting pitolisant.” 5 of these patients were taking an anti-cataplectic agent at the time of starting pitolisant (sodium oxybate 3, venlafaxine 2). Conclusion While a relatively small sample size, these results demonstrate that in a “real world” uncontrolled population of refractory/challenging NT1 patients, pitolisant is an effective anti-cataplectic agent. As there are relatively few treatment options for NT1, clinicians should consider use of pitolisant for patients with cataplexy, and further consideration for adding an indication for pitolisant to treat cataplexy is warranted. Support Harmony Biosciences (PEACE trial)

0769 FDG-PET Imaging In Narcolepsy Type 1, Idiopathic Hypersomnia, And Non-Sleepy Controls

Abstract Introduction Functional imaging of narcolepsy type 1 (NT1) has shown disparate results, with evidence for both regional hyper- and hypo-metabolism. A FDG-PET study of idiopathic hypersomnia (IH) demonstrated regional hypermetabolism within the salience network. Methods Patients with NT1 (n=14) or IH (n=16) were recruited, with age-matched, non-sleepy controls (HC, n=8). Patients discontinued treatment for ≥5 half-lives. Participants underwent injection of 18F-fludeoxyglucose (FDG) in a dimly-lit room and were asked to remain awake, seated quietly. Simultaneous 6-channel EEG, EOG, and EMG were collected. Participants were alerted by a loud noise if sleep onset was observed. Thirty minutes after injection, patients underwent 36-minute PET scan. Images were spatially normalized to MPRAGE images and analyzed for group differences using SPM8. Results Groups were similar in age (NT1: 30.0 (+/-SD 8.3), IH: 36.3 (+/-12.4), HC: 33.2 (+/-16.2), p=0.29) and gender (%women, NT1: 71%, IH: 87.5%, HC: 62.5%, p=0.37). Patients were sleepier than controls by Epworth (NT1: 18.2 (+/-3.5), IH: 15.8 (+/-3.2), HC: 5.0 (+/-2.7), p<0.0001) and MSLT mean latency (NT1: 2.0 (+/-1.4), IH: 5.1 (+/-1.7), HC: 14.6 (+/-2.6), p<0.0001). Despite attempts to remain awake, NT1 patients had difficulty maintaining wakefulness during uptake, obtaining 6.2 (+/-5.9) minutes sleep versus <1 minute for the other groups. Compared to controls, NT1 patients demonstrated increased activation in bilateral precentral gyri, left postcentral gyrus, left middle frontal gyrus, right insula, right inferior and superior temporal gyri, right fusiform gyrus, and bilateral inferior frontal gyri. Compared to controls, IH patients demonstrated increased activation in bilateral precuneus, bilateral inferior and middle frontal gyri, left middle and superior temporal gyri, left inferior parietal lobule, and left anterior cingulate. Conclusion Different patterns of metabolic activity are seen in two hypersomnia disorders, implying disease-specific activity rather than non-specific sleepiness. Inadvertent sleep during uptake is more common in NT1. Support K23 NS083748

0142 TAK-925, an Orexin 2 Receptor-Selective Agonist, Enhanced Cortical Arousal in a Narcolepsy Mouse Model Different from Effects of Modafinil

Abstract Introduction Patients with narcolepsy type 1 (NT1) suffer from distressing symptoms such as excessive daytime sleepiness (EDS) and cataplexy. Modafinil is widely used as a therapy for NT1; however, it has limited efficacy for EDS and no efficacy for cataplexy. TAK-925 is an orexin 2 receptor (OX2R)-selective agonist which improves multiple symptoms of narcolepsy such as fragmentation of wakefulness and cataplexy-like episodes, and also reduces weight gain, in orexin/ataxin-3 mice, a narcolepsy mouse model. An early proof of concept study showed TAK-925 increased wakefulness compared to placebo in individuals with NT1; however, a head-to-head comparison between TAK-925 and modafinil in NT1 has not been performed to date. In this study, we carefully compared the wake-promoting effects of TAK-925 and modafinil in orexin/ataxin-3 mice. Methods TAK-925 or modafinil was administered to orexin/ataxin-3 mice at zeitgeber time 12, and the sleep/wakefulness states were evaluated based on electroencephalogram (EEG) and electromyogram measurements. EEG spectral analysis was performed by fast Fourier transform during wakefulness. EEG frequency band was divided into five frequency bands: delta, theta, alpha, beta, and gamma. Results Both TAK-925 and modafinil significantly increased wakefulness time, and ameliorated fragmentation of wakefulness, in orexin/ataxin-3 mice during active phase. In contrast, TAK-925, but not modafinil, significantly decreased delta power, and increased alpha and gamma power during wakefulness in orexin/ataxin-3 mice, suggesting a shift in EEG power density toward higher frequencies. Conclusion TAK-925, but not modafinil, enhanced cortical arousal and suppressed signs of somnolence and drowsiness. In a phase 1 study in individuals with NT1, TAK-925 was found to have pronounced effects on the maintenance of wakefulness test, reaching a total duration of 40 minutes wake time at some doses tested. Spectral analysis will be evaluated in future studies in NT1 patients. Support This work was conducted by Takeda Pharmaceutical Company Limited.

CSF and serum ferritin levels in narcolepsy type 1 comorbid with restless legs syndrome.

ObjectivesTo investigate whether cerebrospinal fluid (CSF) and serum ferritin levels differ between patients with narcolepsy type 1 (NT1) comorbid with restless legs syndrome (RLS) or periodic leg movements during sleep (PLMS), and patients with NT1 or controls without comorbid RLS or PLMS.MethodsSixty‐six drug‐free patients with NT1 (44 males, age 38.5 years [14–81]) were enrolled, including 20 with RLS, 18 with PLMS index ≥15/h (six with both RLS and PLMS). Thirty‐eight drug‐free patients (12 males, age 22.5 years [12–61]) referred for sleepiness complaint, but without central hypersomnia, RLS, PLMS were included as controls. Clinical, electrophysiological and biological (CSF/serum ferritin, orexin [ORX]) data were quantified.ResultsNT1 patients with and without RLS did not differ for age, gender, and body mass index (BMI). No between‐group differences were found for CSF ferritin, ORX, and serum ferritin levels. No CSF ferritin, ORX, and serum ferritin level differences were found between NT1 patients with and without PLMS, or with RLS or PLMS versus not. CSF‐ferritin levels were not different between NT1 and controls in adjusted analyses. CSF‐ferritin levels in the whole population correlated positively with age, serum‐ferritin, BMI, negatively with ORX, but not with PLMS index. In NT1, CSF‐ferritin levels correlated with age and serum‐ferritin but not with PLMS.ConclusionThe absence of CSF ferritin deficiency in NT1 with comorbid RLS or PLMS indicates normal brain iron levels in that condition. This result suggests that the frequent association between RLS, PLMS, and NT1 is not based on alterations in brain iron metabolism, a pathophysiological mechanism involved in primary RLS.

HLA associations in narcolepsy type 1 persist after the 2009 H1N1 pandemic

We aimed to compare HLA-DQB1-associations in narcolepsy type 1 (NT1) patients with disease onset before and after the 2009 H1N1 pandemic in a large Dutch cohort. 525 NT1 patients and 1272 HLA-DQB1*06:02-positive healthy controls were included. Because of the discussion that has arisen on the existence of sporadic and post-H1N1 NT1, HLA-DQB1-associations in pre- and post-H1N1 NT1 patients were compared. The associations between HLA-DQB1 alleles and NT1 were not significantly different between pre- and post-H1N1 NT1 patients. Both HLA-DQB1-associations with pre- and -post H1N1 NT1 reported in recent smaller studies were replicated. Our findings combine the results of studies in pre- and post-H1N1 NT1 and argue against considering post-H1N1 NT1 as a different entity.

Adherence to wakefulness promoting medication in patients with narcolepsy

ObjectiveNarcolepsy management usually requires lifelong pharmacotherapy. However, we know little about adherence to prescribed treatment in narcolepsy. We assessed adherence to wakefulness-promoting agents in narcolepsy patients. Patients and methodsWe retrospectively assessed adherence to wakefulness promoting medication in patients with narcolepsy using the Medicines Possession Ratio (MPR). Three levels of adherence were defined: poor (≤50%), intermediate (51–79%), and good (≥80%). Refractory daytime sleepiness was defined as an Epworth sleepiness scale (ESS) score >12 despite trialling at least three wakefulness-promoting agents. We compared demographic and clinical factors, and prescribed medications between patients, stratified by levels of adherence, as well as by presence or not of refractory sleepiness. ResultsWe included 116 patients with narcolepsy (54.3% female, mean age 39.4 (±14) years). In sum, 93 (80.2%) patients had a diagnosis of narcolepsy type 1 (NT1), and 23 (19.8%) of type 2 (NT2). Suboptimal symptom control was common: 39.8% had refractory sleepiness, and 47.3% of NT1 patients had persistent cataplexy. Good adherence was seen in only 55.2% of patients, while 12.9% were intermediately and 31.9% poorly adherent. Patients with poor adherence were more likely to have a diagnosis of NT2, but adherence did not vary according to gender, age, the presence of psychiatric co-morbidity, or the presence of apparent intractable symptoms. Levels of good adherence to therapy were no better in patients with refractory sleepiness than in those with satisfactory symptom control (56.5% vs 54.3%; p = 0.81). ConclusionSuboptimal adherence to prescribed therapy is common in narcolepsy patients, including those with apparent intractable symptoms, and particularly in patients with NT2.

Structural organization of dream experience during daytime sleep-onset rapid eye movement period sleep of patients with narcolepsy type 1.

To assess the frequency of dream experience (DE) developed during naps at Multiple Sleep Latency Test (MSLT) by patients with narcolepsy type 1 (NT1) and establish, using story-grammar analysis, the structural organization of DEs developed during naps with sleep onset rapid eye movement (REM) period (SOREMP) sleep compared with their DEs during early- and late-night REM sleep. Thirty drug-free cognitively intact adult NT1 patients were asked to report DE developed during each MSLT nap. Ten NT1 patients also spent voluntarily a supplementary night being awakened during the first-cycle and third-cycle REM sleep. Patients provided dream reports, white dreams, and no dreams, whose frequencies were matched in naps with SOREMP versus non-REM (NREM) sleep. All dream reports were then analyzed using story-grammar rules. DE was recalled in detail (dream report) by NT1 patients after 75% of naps with SOREMP sleep and after 25% of naps with NREM sleep. Dream reports were provided by 8 out of 10 NT1 patients after both awakenings from nighttime REM sleep. Story-grammar analysis of dream reports showed that SOREMP-DEs are organized as hierarchically ordered sequences of events (so-called dream-stories), which are longer and more complex in the first and fourth SOREMP naps and are comparable with nighttime REM-DEs. The similar structural organization of SOREMP-DEs with nighttime REM-DEs indicates that their underlying cognitive processes are highly, albeit not uniformly, effective during daytime SOREMP sleep. Given the peculiar neurophysiology of SOREMP sleep, investigating SOREMP-DEs may cast further light on the relationships between the neurophysiological and psychological processes involved in REM-dreaming.

Screening for autoantibody targets in post-vaccination narcolepsy using proteome arrays.

Narcolepsy type 1 (NT1) is a chronic sleep disorder caused by a specific loss of hypocretin-producing neurons. The incidence of NT1 increased in Sweden, Finland and Norway following Pandemrix®-vaccination, initiated to prevent the 2009 influenza pandemic. The pathogenesis of NT1 is poorly understood, and causal links to vaccination are yet to be clarified. The strong association with Human leukocyte antigen (HLA) DQB1*06:02 suggests an autoimmune pathogenesis, but proposed autoantigens remain controversial. We used a two-step approach to identify autoantigens in patients that acquired NT1 after Pandemrix®-vaccination. Using arrays of more than 9000 full-length human proteins, we screened the sera of 10 patients and 24 healthy subjects for autoantibodies. Identified candidate antigens were expressed in vitro to enable validation studies with radiobinding assays (RBA). The validation cohort included NT1 patients (n=39), their first-degree relatives (FDR) (n=66), population controls (n=188), and disease controls representing multiple sclerosis (n=100) and FDR to type 1 diabetes patients (n=41). Reactivity towards previously suggested NT1 autoantigen candidates including Tribbles homolog 2, Prostaglandin D2 receptor, Hypocretin receptor 2 and α-MSH/proopiomelanocortin was not replicated in the protein array screen. By comparing case to control signals, three novel candidate autoantigens were identified in the protein array screen; LOC401464, PARP3 and FAM63B. However, the RBA did not confirm elevated reactivity towards either of these proteins. In summary, three putative autoantigens in NT1 were identified by protein array screening. Autoantibodies against these candidates could not be verified with independent methods. Further studies are warranted to identify hypothetical autoantigens related to the pathogenesis of Pandemrix®-induced NT1.

HLA high-resolution typing by next-generation sequencing in Pandemrix-induced narcolepsy.

The incidence of narcolepsy type 1 (NT1) increased in Sweden following the 2009–2010 mass-vaccination with the influenza Pandemrix-vaccine. NT1 has been associated with Human leukocyte antigen (HLA) DQB1*06:02 but full high-resolution HLA-typing of all loci in vaccine-induced NT1 remains to be done. Therefore, here we performed HLA typing by sequencing HLA-DRB3, DRB4, DRB5, DRB1, DQA1, DQB1, DPA1 and DPB1 in 31 vaccine-associated NT1 patients and 66 of their first-degree relatives (FDR), and compared these data to 636 Swedish general population controls (GP). Previously reported disease-related alleles in the HLA-DRB5*01:01:01-DRB1*15:01:01-DQA1*01:02:01-DQB1*06:02:01 extended haplotype were increased in NT1 patients (34/62 haplotypes, 54.8%) compared to GP (194/1272 haplotypes, 15.3%, p = 6.17E-16). Indeed, this extended haplotype was found in 30/31 patients (96.8%) and 178/636 GP (28.0%). In total, 15 alleles, four extended haplotypes, and six genotypes were found to be increased or decreased in frequency among NT1 patients compared to GP. Among subjects with the HLA-DRB5*01:01:01-DRB1*15:01:01-DQA1*01:02-DQB1*06:02 haplotype, a second DRB4*01:03:01-DRB1*04:01:01-DQA1*03:02//*03:03:01-DQB1*03:01:01 haplotype (p = 2.02E-2), but not homozygosity for DRB1*15:01:01-DQB1*06:02:01 (p = 7.49E-1) conferred association to NT1. Alleles with increased frequency in DQA1*01:02:01 (p = 1.07E-2) and DQA1*03:02//*03:03:01 (p = 3.26E-2), as well as with decreased frequency in DRB3*01:01:02 (p = 8.09E-3), DRB1*03:01:01 (p = 1.40E-2), and DQB1*02:01:01 (p = 1.40E-2) were found among patients compared to their FDR. High-resolution HLA sequencing in Pandemrix-associated NT1 confirmed the strong association with the DQB1*06:02:01-containing haplotype but also revealed an increased association to the not previously reported extended HLA-DRB4*01:03:01-DRB1*04:01:01-DQA1*03:02//*03:03:01-DQB1*03:01:01 haplotype. High-resolution HLA typing should prove useful in dissecting the immunological mechanisms of vaccination-associated NT1.

Clinical autonomic dysfunction in narcolepsy type 1.

(1) To compare the presence of autonomic symptoms using the validated SCOPA-AUT questionnaire in untreated patients with narcolepsy type 1 (NT1) to healthy controls, (2) to study the determinants of a high total SCOPA-AUT score in NT1, and (3) to evaluate the effect of drug intake on SCOPA-AUT results in NT1. The SCOPA-AUT questionnaire that evaluates gastrointestinal, urinary, cardiovascular, thermoregulatory, pupillomotor, and sexual dysfunction was completed by 92 consecutive drug-free adult NT1 patients (59 men, 39.1 ± 15.6 years old) and 109 healthy controls (63 men, 42.6 ± 18.2 years old). A subgroup of 59 NT1 patients completed the questionnaire a second time, under medication (delay between two evaluations: 1.28 ± 1.14 years). Compared to controls, NT1 patients were more frequently obese, had more dyslipidemia, with no difference for age and gender. The SCOPA-AUT score of NT1 was higher than in controls in crude and adjusted models. Patients experienced more problems than controls in all subdomains. A higher score in NT1 was associated with older age, longer disease duration, altered quality of life and more depressive symptoms, but not with orexin levels and disease severity. Among patients evaluated twice, the SCOPA-AUT score total did not differ according to treatment status, neither did each subdomain. We captured a frequent and large spectrum of clinical autonomic dysfunction in NT1, with impairment in all SCOPA-AUT domains, without key impact of medication intake. This assessment may allow physicians to screen and treat various symptoms, often not spontaneously reported but associated with poor quality of life.