HLA-DQB1*06:02 allele frequency and clinic-polysomnographic features in Saudi Arabian patients with narcolepsy

The Lehigh Valley Health Network Narcolepsy Cohort: clinical and polysomnographic analysis of 304 cases

STUDY OBJECTIVE

We aimed to characterize clinical features, comorbidities, and polysomnographic characteristics of a large cohort of patients with narcolepsy.

METHODS

We undertook a retrospective chart and polysomnographic review of all patients with a diagnosis of narcolepsy type 1 (NT1) or narcolepsy type 2 (NT2) seen within the Lehigh Valley Health Network between 2000 and 2022.

RESULTS

We found 304 cases with a diagnosis of narcolepsy (52 NT1, 252 NT2), based on International Classification of Sleep Disorders, third edition criteria. Compared to NT2, patients with NT1 had younger diagnosis age (24.5 vs 27.4 years, P = .03), shorter diagnostic gap (3.0 vs 4.6 years, P = .002), more frequent sleep paralysis (55.8% vs 19.4%, P < .0001) and hypnagogic hallucinations (46.2% vs 25.4%, P = .003), and higher Epworth Sleepiness Scale scores (17.8 vs 16.7, P = .02). The most common comorbid sleep disorders were breathing disorders (17.4%) and insomnia (15.5%). Migraine was the most common neurological disorder. Depression was more common in NT2 than NT1 (12 [23.1%] vs 94 [37.3%], P = .05). On the Multiple Sleep Latency Test, patients with NT1 had more sleep onset rapid eye movement periods than patients with NT2 (≥ 3 sleep onset rapid eye movement periods in 59.2% vs 26.9%, P < .0001). Only in NT2, hypnagogic hallucinations and higher Epworth Sleepiness Scale scores were associated with higher numbers of sleep onset rapid eye movement periods (P = .0277 and P = .0179, respectively).

CONCLUSION

This is one of the largest monocentric studies to date of patients with narcolepsy and confirms the frequent comorbidities of narcolepsy. Specific clinical characteristics and comorbidities may help differentiate NT1 from NT2.

CITATION

Jiang RY, Rochart R, Chu I, Duka S, Vendrame M. The Lehigh Valley Health Network Narcolepsy Cohort: clinical and polysomnographic analysis of 304 cases. J Clin Sleep Med. 2025;21(3):479-491.

Development and validation of the narcolepsy severity scale in school aged children

OBJECTIVE

To develop and psychometrically test the pediatric narcolepsy severity scale (P-NSS) for pediatric with narcolepsy type 1 (NT1).

METHODS

Item pool was formed based on literature review, clinical judgement of the expert panel and input of the narcoleptic patients and their parents. Psychometric properties were evaluated after applying the P-NSS in a sample of 200 patients (8-18 years age) with narcolepsy. Analyses included item analysis, validity analysis and reliability analysis.

RESULTS

P-NSS consisted four factors with a total of 17 items. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) revealed four distinct and theoretically coherent factors, explaining 63.4% of the total variance. The fitting results of the CFA model were χ2/dƒ = 2.235, GFI = 0.876, AGFI = 0.822, RMSEA = 0.079, TLI = 0.908, CFI = 0.927. P-NSS score is correlated with Pediatric Daytime Sleepiness Scale (r = 0.512, P < 0.01), Epworth Sleepiness Scale for Children and Adolescents (r = 0.355, P < 0.01) and Narcolepsy quality-of-life instrument with 21 questions (r = -0.512, P < 0.01). Cronbach's α coefficient for P-NSS and four dimensions were from 0.732 to 0.915. The split-half reliability was 0.882 (P < 0.01).

CONCLUSION

P-NSS is proved to be a reliable and valid measure for Chinese children with NT1. It may serve in China as a valuable and easily accessible outcome measure for using in narcolepsy trials, the clinic with improved responsiveness and long term follow-up.

Genetics and epigenetics of rare hypersomnia

Herein we focus on connections between genetics and some central disorders of hypersomnolence - narcolepsy types 1 and 2 (NT1, NT2), idiopathic hypersomnia (IH), and Kleine-Levin syndrome (KLS) - for a better understanding of their etiopathogenetic mechanisms and a better diagnostic and therapeutic definition. Gene pleiotropism influences neurological and sleep disorders such as hypersomnia; therefore, genetics allows us to uncover common pathways to different pathologies, with potential new therapeutic perspectives. An important body of evidence has accumulated on NT1 and IH, allowing a better understanding of etiopathogenesis, disease biomarkers, and possible new therapeutic approaches. Further studies are needed in the field of epigenetics, which has a potential role in the modulation of biological specific hypersomnia pathways.

TCM syndrome differentiation and treatment of narcolepsy based on neurobiological mechanism: A review

Narcolepsy is a relatively rare brain disorder caused by the selective loss of orexin neurons. Narcolepsy is divided into Narcolepsy Type 1 (NT1) and Narcolepsis Type 2 (NT2). The pathogenesis of NT1 has been well established due to the severe loss of orexin neurons, while NT2 is still poorly understood, and little is known about its underlying neurobiological mechanisms. human leukocyte antigen alleles have been found to strongly influence the development of narcolepsy, with more than 90% of NT1 patients carrying the human leukocyte antigen II allele DQB1*06:02. In addition to the genetic evidence for the DQBI*06:02 allele, some other evidence suggests that a T cell-mediated immune mechanism destroys the orexin neurons of NT1, with CD4 + T cells being key. For this disease, traditional Chinese medicine (TCM) therapy has its own characteristics and advantages, especially the combination of acupuncture and medicine in the treatment of this disease in TCM, which has made considerable and gratifying progress. The purpose of this review is to introduce the frontier progress of neurobiology of narcolepsy, and to explore the syndrome differentiation and treatment of narcolepsy with the combined use of TCM and Western medicine combined with TCM.

Association between HLA alleles and sub-phenotype of childhood steroid-sensitive nephrotic syndrome

BACKGROUND

Few studies have addressed the effects of human leukocyte antigen (HLA) alleles on different clinical sub-phenotypes in childhood steroid-sensitive nephrotic syndrome (SSNS), including SSNS without recurrence (SSNSWR) and steroid-dependent nephrotic syndrome/frequently relapse nephrotic syndrome (SDNS/FRNS). In this study, we investigated the relationship between HLA system and children with SSNSWR and SDNS/FRNS and clarified the value of HLA allele detection for precise typing of childhood SSNS.

METHODS

A total of 241 Chinese Han individuals with SSNS were genotyped using GenCap-WES Capture Kit, and four-digit resolution HLA alleles were imputed from available Genome Wide Association data. The distribution and carrying frequency of HLA alleles in SSNSWR and SDNS/FRNS were investigated. Additionally, logistic regression and mediating effects were used to examine the relationship between risk factors for disease process and HLA system.

RESULTS

Compared with SSNSWR, significantly decreased serum levels of complement 3 (C3) and complement 4 (C4) at onset were detected in SDNS/FRNS (C3, P < 0.001; C4, P = 0.018). The average time to remission after sufficient initial steroid treatment in SDNS/FRNS was significantly longer than that in SSNSWR (P = 0.0001). Low level of C4 was further identified as an independent risk factor for SDNS/FRNS (P = 0.008, odds ratio = 0.174, 95% confidence interval 0.048-0.630). The HLA-A*11:01 allele was independently associated with SSNSWR and SDNS/FRNS (P = 0.0012 and P = 0.0006, respectively). No significant HLA alleles were detected between SSNSWR and SDNS/FRNS. In addition, a mediating effect among HLA-I alleles (HLA-B*15:11, HLA-B*44:03 and HLA-C*07:06), C4 level and SDNS/FRNS was identified.

CONCLUSIONS

HLA-I alleles provide novel genetic markers for SSNSWR and SDNS/FRNS. HLA-I antigens may be involved in steroid dependent or frequent relapse in children with SSNS as mediators of immunoregulation.

A 10-Year Longitudinal Observational Study Of Cataplexy In A Cohort Of Narcolepsy Type 1 Patients

PURPOSE

Narcolepsy type 1 (NT1) is thought to have a chronic persistent course. This study aimed to assess the natural course of cataplexy in patients with NT1 at 2, 6, and 10 years after stabilizing symptoms. Other secondary objectives included assessing sleep quality, body mass index (BMI), and comorbidities at recruitment and 10 years later.

PATIENTS AND METHODS

Cataplexy symptoms, the Epworth sleepiness scale (ESS), sleep quality (assessed using the Pittsburgh sleep quality index [PSQI]), BMI, and comorbid conditions were prospectively monitored in 38 patients with NT1. The study sample comprised 38 patients with narcolepsy (males=27). The mean ages at disease onset and recruitment were 17.7 ± 5.6 years and 24.3 ± 8.6 years, respectively.

RESULTS

In 42% of the cohort, the anti-cataplectic medications were stopped at the end of the study without disturbing symptoms of cataplexy. Additionally, there was an apparent significant reduction in the frequency of cataplexy over time. The mean ESS score decreased by more than 4 points from 19.4 ± 2.9 to 15 ± 4.3 (p<0.001) while on the same pharmacotherapy. The number of patients with a PSQI score of <5 (indicating good sleep quality) increased from 6 (15.8%) to 15 (39.5%) (p=0.004). The BMI increased from 30 ± 5.1 to 33.3 ± 6 kg/m² (p=0.001). No changes were documented in comorbidities.

CONCLUSION

The findings suggest that the course of NT1 is not stable. Over a 10-year period, cataplexy symptoms improved or disappeared in a large proportion of patients, and there was an improvement in daytime sleepiness and nighttime sleep quality. More prospective studies that repeatedly monitor CSF-HCRT are needed to confirm the current findings.

Immune-mediated comorbidities in Saudi patients with narcolepsy

Background: Autoimmunity has been proposed as a cause of narcolepsy. A few studies have assessed comorbid autoimmune diseases in patients with narcolepsy, with conflicting results; however, no study has assessed autoimmune diseases in Arab narcolepsy patients. This study aimed to assess the coexistence of immune-mediated conditions such as allergies, autoimmune diseases, and autoinflammatory diseases in patients with narcolepsy type 1 (with cataplexy) (NT1) and narcolepsy type 2 (without cataplexy) (NT2). Methods: Personal and family history of autoimmune/autoinflammatory and allergic disorders was collected using a questionnaire in 80 consecutive Saudi patients with narcolepsy (46 NT1 and 24 NT2), who were diagnosed according to the International Classification of Sleep Disorders, Third Edition. The control group comprised 222 adults from the general population. Results: Comorbid autoimmune/autoinflammatory diseases were reported by 21.4% of the NT1 patients, and 12.2% of the controls, with no significant difference between cases and controls in a model adjusted for confounding covariates. However, allergic disorders were significantly more prevalent among NT1 patients. Both comorbid autoimmune/autoinflammatory and allergic disorders were significantly more prevalent among NT2 patients compared to controls. No differences in demographic and clinical characteristics were detected between narcolepsy patients with and without autoimmune/autoinflammatory diseases. Conclusion: NT1 is not associated with increased comorbid autoimmune diseases in the studied sample of Saudi patients. However, autoimmune diseases are associated with NT2, and allergic disorders are associated with both NT1 and NT2. These findings suggest the existence of dysregulation in the immune system of narcolepsy patients that requires further research.