ABSTRACT
This study was thought to characterized clinical and laboratory findings of a narcoleptic patients in an out patients unit at São Paulo, Brazil. METHOD: 28 patients underwent polysomnographic recordings (PSG) and Multiple Sleep Latency Test (MSLT) were analyzed according to standard criteria. The analysis of HLADQB1*0602 allele was performed by PCR. The Hypocretin-1 in cerebral spinal fluid (CSF) was measured using radioimmunoassay. Patients were divided in two groups according Hypocretin-1 level: Normal (N) - Hypocretin-1 higher than 110pg/ml and Lower (L) Hypocretin-1 lower than 110 pg/ml. RESULTS: Only 4 patients of the N group had cataplexy when compared with 14 members of the L group (p=0.0002). DISCUSSION: This results were comparable with other authors, confirming the utility of using specific biomarkers (HLA-DQB1*0602 allele and Hypocretin-1 CSF level) in narcolepsy with cataplexy. However, the HLADQB1*0602 allele and Hypocretin-1 level are insufficient to diagnose of narcolepsy without cataplexy.
Este estudo foi idealizado para avaliar as características clinicas e laboratoriais de uma população de narcolépticos atendidos num centro de referência na cidade de São Paulo (Brasil). MÉTODO: 28 pacientes realizaram polissonografia e teste de múltiplas latências do sono segundo critérios internacionais. O alelo HLADQB1*0602 foi identificado por PCR. A Hipocretina-1 no líquido cefalorradiano (LCR) foi mensurada por radioimunoensaio. Os pacientes foram divididos em 2 grupos conforme o nível de Hipocretina-1. Normal (N) - Hypocretin-1 >110pg/ml e baixa (B) - Hypocretina-1 <110pg/ml. RESULTADOS: Somente 4 pacientes do grupo N tinham cataplexia quando comparados com 14 pacientes do grupo B (p=0,0002). DISCUSSÃO: Estes resultados foram comparáveis com outros autores, confirmando a utilidade do uso de biomarcadores específicos (HLA-DQB1*0602 e nível da hipocretina-1 no LCR) em narcolepsia com cataplexia. Porém, o alelo HLADQB1*0602 e a dosagem da Hipocretina-1 são insuficientes para o diagnóstico da narcolepsia sem cataplexia.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , HLA-DQ Antigens/genetics , Intracellular Signaling Peptides and Proteins/cerebrospinal fluid , Membrane Glycoproteins/genetics , Narcolepsy/diagnosis , Neuropeptides/cerebrospinal fluid , Alleles , Biomarkers , Cataplexy/cerebrospinal fluid , Cataplexy/diagnosis , Cataplexy/genetics , Narcolepsy/cerebrospinal fluid , Narcolepsy/genetics , Polymerase Chain Reaction , Polysomnography , RadioimmunoassayABSTRACT
OBJECTIVE: Narcolepsy (with and without cataplexy) and idiopathic hypersomnia, are disorders with common features but with different HLA-DQB1*0602 allele prevalence. The present study describes the prevalence of HLA-DQB1*0602 allele in narcoleptics with and without cataplexy and in patients with idiopathic hypersomnia. METHOD: Subjects comprised 68 patients who were diagnosed for narcolepsy or idiopathic hypersomnia and 23 healthy controls according to the International Classification of Sleep Disorders-2. Subjects comprised 43 patients with narcolepsy and cataplexy, 11 patients with narcolepsy but without cataplexy, 14 patients with idiopathic hypersomnia and 23 healthy controls. Genotyping of HLA-DQB1*0602 allele was performed for all subjects. RESULTS: The prevalence of the HLA-DQB1*0602 allele was increased in idiopathic hypersomnia and in narcoleptic patients with and without cataplexy when compared to healthy subjects (p = 0.04; p = 0.03 and p < 0.0001, respectively). CONCLUSIONS: This finding is in accordance with those of previous studies. The gold standard exam of narcolepsy with cataplexy is Hypocretin-1 dosage, but in patients without cataplexy and idiopathic hypersomnia, there are no specific diagnostic lab findings. The presence of the HLA-DQB1* 0602 allele may be important for the differential diagnosis of situations that resemble those sleep disorders such as secondary changes in sleep structure due to drugs' consumption.
OBJETIVO: Narcolepsia (com e sem cataplexia) e hipersonolência idiopática são transtornos com características clínicas comuns, mas com prevalências do alelo HLA-DQB1*0602 diferentes. Este estudo descreve a prevalência do alelo HLA-DQB1*0602 em pacientes narcolépticos com e sem cataplexia e em pacientes com hipersonolência idiopática. MÉTODO: A amostra consistiu de 68 pacientes com diagnóstico de narcolepsia ou hipersonolência idiopática e 23 controles saudáveis segundo o International Classification of Sleep Disorders-2. A amostra foi composta de 43 pacientes com narcolepsia e cataplexia, 11 pacientes com narcolepsia e sem cataplexia, 14 pacientes com hipersonolência idiopática e 23 controles saudáveis. A análise da presença do alelo HLA-DQ*0602 foi realizada em todos os sujeitos. RESULTADOS: A prevalência do alelo HLA-DQB1*0602 foi maior nos grupos de pacientes com hipersonolência idiopática e em pacientes narcolépticos com e sem cataplexia quando comparada com a dos sujeitos saudáveis (p = 0,04; p = 0,03 e p < 0,0001, respectivamente). CONCLUSÕES: Os resultados são compatíveis com o de estudos anteriores. O exame padrão-ouro para a confirmação da narcolepsia em pacientes com cataplexia é a dosagem de hipocretina, mas em pacientes sem cataplexia e hipersonolência idiopática não há testes laboratoriais específicos para o diagnóstico. A presença do alelo HLA-DQB1*0602 pode ser importante no diagnóstico diferencial de situações semelhantes a esses distúrbios do sono, como alterações secundárias na estrutura do sono causadas por consumo de drogas.
Subject(s)
Adolescent , Adult , Aged , Child, Preschool , Female , Humans , Male , Middle Aged , Young Adult , Alleles , HLA-DQ Antigens/genetics , Idiopathic Hypersomnia/diagnosis , Idiopathic Hypersomnia/genetics , Membrane Glycoproteins/genetics , Narcolepsy/diagnosis , Narcolepsy/genetics , Brazil , Case-Control Studies , Chi-Square Distribution , Diagnosis, Differential , Statistics, Nonparametric , Young AdultABSTRACT
BACKGROUND: Studies have shown a high prevalence of migraine among narcoleptic patients. HLA-DQB1*0602 and HLA DRB1 alleles are closely associated with narcolepsy. An increase in the HLA-DRB1 allele frequency in patients with visual aura has raised greater awareness of the genetic background in migraine. PURPOSE: Since the regions DR and DQ of the HLA are in tightly linkage desiquilibrium we hypothesize that HLA-DQB1*0602 might be associated to the pathophysiology of migraine. METHOD: We analyzed the presence of HLA DQB1*0602 allele in 50 healthy subjects with no history of migraine, 53 patients with migraine without aura and 52 patients with migraine with aura. RESULTS: There was no difference in the frequency of HLA DQB1*0602 allele when control subjects and all patients were compared. We failed to note any difference in frequencies when comparing migraine patients with and without aura. CONCLUSION: Further studies with different patient populations, with other hypothalamic markers (melatonin, hypocretin) in migraine patients may shed light on to its pathophysiology.
CONTEXTO: Estudos têm demonstrado o aumento da prevalência de enxaqueca em pacientes com narcolepsia, um distúrbio de sono associado a um gene do sistema HLA, o alelo HLA-DQB1*0602. As regiões DQ e DR do HLA estão em alto desequilíbrio de ligação e já foi descrito um aumento da freqüência do alelo HLA DRB1 em pacientes com enxaqueca com aura visual, o que fortalece uma hipótese de herança genética para a enxaqueca. OBJETIVO: Nossa hipótese é que o alelo HLA-DQB1*0602 pode estar relacionado com a fisiopatologia da enxaqueca destes pacientes. MÉTODO: Nós analisamos a presença do alelo HLA-DQB1*0602 em 50 voluntários sadios sem história de enxaqueca, 53 pacientes com enxaqueca sem aura e 52 pacientes com aura. RESULTADOS: Não houve diferença entre os controles sadios e os pacientes com enxaqueca. Não houve diferença entre os pacientes com enxaqueca com e sem aura. CONCLUSÃO: Futuros estudos com diferentes populações, com outros marcadores (melatonina e hipocretina) em pacientes com enxaqueca devem ser realizados para melhor esclarecimento de fisiopatologia.
Subject(s)
Adult , Female , Humans , Male , Alleles , HLA-DQ Antigens/genetics , Membrane Glycoproteins/genetics , Migraine with Aura/genetics , Migraine without Aura/genetics , Case-Control Studies , Genetic Markers , Genetic Predisposition to Disease , Polymerase Chain Reaction , PrevalenceABSTRACT
OBJECTIVES: Narcolepsy is a sleep disorder, characterized by excessive daytime sleepiness, cataplexy, sleep paralysis and hypnagogic hallucination. Among these symptoms, cataplexy is one of the most pathognomonic symptoms in narcolepsy. This study was designed to investigate the clinical features, frequency of DQB1*0602 and CSF hypocretin levels in Korean narcoleptics with cataplexy to compare with those who have not cataplexy. METHODS: From August 2003 to July 2005, we selected 72 patients who have narcolepsy confirmed by nocturnal polysomnography and multiple sleep latency test (MSLT) as well as their history and clinical symptoms at Sleep Disorders Clinic of St. Vincent's Hospital, Catholic University of Korea. Patients were divided into 56 cataplexy-positive group (narcolepsy with cataplexy group) and 12 cataplexy-negative group (narcolepsy without cataplexy group). HLA typing was done in all patients for the presence of DQB1*0602, and patients received spinal tapping to measure the level of CSF hypocretin. Clinical variables were examined by semi-structured interview for narcolepsy patients. RESULTS: 1) In cataplexy-positive group, compared with cataplexy-negative group, the frequency of HLA-DQB1*0602 was found to be significantly increased (50 subjects, 89.3% vs. 8 subjects, 50.0%)(p=0.000). 2) In 48 out of 56 cataplexy-positive patients (85.7%), hypocretin levels were decreased (< or =110 pg/ml) or were below the detection limit of assay (<40 pg/ml). However, only 6 out of 16 cataplexy-negative patients (37.5%) exhibited decreased hyopcretin level. The difference between two groups were statistically significant (p=0.000). 3) Cataplexy-positive group, compared to cataplexy-negative group, reported more frequent hypnagogic hallucinations (36 subjects, 64.3% vs. 4 subjects, 25.0%)(p=0.005). However, there were no significant differences in frequency or severity of daytime sleepiness, sleep paralysis and demographic data. 4. In nocturnal polysomnography and MSLT findings, there were no significant differences in all sleep parameters between two groups. CONCLUSION: Higher frequency of HLA-DQB1*0602, and lower hypocretin levels in cataplexy-positive groups than catapelxy-negatives suggest that narcoleptics with cataplexy might be a etiologically different disease entity from narcoleptics without cataplexy. Additionally, Current criteria prevail for the diagnosis of narcolepsy need to be reclassified according to the presence of cataplexy or not.