Outi Saarenpää-Heikkilä

AS03 Adjuvanted AH1N1 Vaccine Associated with an Abrupt Increase in the Incidence of Childhood Narcolepsy in Finland

Background Narcolepsy is a chronic sleep disorder with strong genetic predisposition causing excessive daytime sleepiness and cataplexy. A sudden increase in childhood narcolepsy was observed in Finland soon after pandemic influenza epidemic and vaccination with ASO3-adjuvanted Pandemrix. No increase was observed in other age groups. Methods Retrospective cohort study. From January 1, 2009 to December 31, 2010 we retrospectively followed the cohort of all children living in Finland and born from January 1991 through December 2005. Vaccination data of the whole population was obtained from primary health care databases. All new cases with assigned ICD-10 code of narcolepsy were identified and the medical records reviewed by two experts to classify the diagnosis of narcolepsy according to the Brighton collaboration criteria. Onset of narcolepsy was defined as the first documented contact to health care because of excessive daytime sleepiness. The primary follow-up period was restricted to August 15, 2010, the day before media attention on post-vaccination narcolepsy started. Findings Vaccination coverage in the cohort was 75%. Of the 67 confirmed cases of narcolepsy, 46 vaccinated and 7 unvaccinated were included in the primary analysis. The incidence of narcolepsy was 9.0 in the vaccinated as compared to 0.7/100,000 person years in the unvaccinated individuals, the rate ratio being 12.7 (95% confidence interval 6.1–30.8). The vaccine-attributable risk of developing narcolepsy was 1∶16,000 vaccinated 4 to 19-year-olds (95% confidence interval 1∶13,000–1∶21,000). Conclusions Pandemrix vaccine contributed to the onset of narcolepsy among those 4 to 19 years old during the pandemic influenza in 2009–2010 in Finland. Further studies are needed to determine whether this observation exists in other populations and to elucidate potential underlying immunological mechanism. The role of the adjuvant in particular warrants further research before drawing conclusions about the use of adjuvanted pandemic vaccines in the future.

Antigenic Differences between AS03 Adjuvanted Influenza A (H1N1) Pandemic Vaccines: Implications for Pandemrix-Associated Narcolepsy Risk

Background Narcolepsy results from immune-mediated destruction of hypocretin secreting neurons in hypothalamus, however the triggers and disease mechanisms are poorly understood. Vaccine-attributable risk of narcolepsy reported so far with the AS03 adjuvanted H1N1 vaccination Pandemrix has been manifold compared to the AS03 adjuvanted Arepanrix, which contained differently produced H1N1 viral antigen preparation. Hence, antigenic differences and antibody response to these vaccines were investigated. Methods and Findings Increased circulating IgG-antibody levels to Pandemrix H1N1 antigen were found in 47 children with Pandemrix-associated narcolepsy when compared to 57 healthy children vaccinated with Pandemrix. H1N1 antigen of Arepanrix inhibited poorly these antibodies indicating antigenic difference between Arepanrix and Pandemrix. High-resolution gel electrophoresis quantitation and mass spectrometry identification analyses revealed higher amounts of structurally altered viral nucleoprotein (NP) in Pandemrix. Increased antibody levels to hemagglutinin (HA) and NP, particularly to detergent treated NP, was seen in narcolepsy. Higher levels of antibodies to NP were found in children with DQB1*06∶02 risk allele and in DQB1*06∶02 transgenic mice immunized with Pandemrix when compared to controls. Conclusions This work identified 1) higher amounts of structurally altered viral NP in Pandemrix than in Arepanrix, 2) detergent-induced antigenic changes of viral NP, that are recognized by antibodies from children with narcolepsy, and 3) increased antibody response to NP in association of DQB1*06∶02 risk allele of narcolepsy. These findings provide a link between Pandemrix and narcolepsy. Although detailed mechanisms of Pandemrix in narcolepsy remain elusive, our results move the focus from adjuvant(s) onto the H1N1 viral proteins.

Maternal and paternal sleep during pregnancy in the Child-sleep birth cohort

STUDY OBJECTIVES Maternal and paternal sleep insufficiency during pregnancy appears to be a risk factor for health and wellbeing in young families. Here, we evaluated the prevalence of sleep insufficiency and symptoms of insomnia during pregnancy (at 32nd pregnancy week) and their relationship to depression, anxiety and environmental stress. METHODS The study is based on a population based sample from Finland consisting of 1667 mothers and 1498 fathers from the Child-sleep birth cohort. We evaluated both the core symptoms of insomnia (sleep onset problems, nocturnal awakenings, too-early awakenings, and poor sleep quality) and the presence of insufficient sleep. Insufficient sleep was defined as a two-hour difference between self-assessed sleep need and reported sleep duration, or sleep duration shorter than six hours per night. RESULTS We found that symptoms of insomnia were more prevalent among women than among men (9.8% vs. 6.2%), whereas sleep debt was less prevalent among women than among men (4.5% vs. 9.6%). Overall, 11.8% of the women and 14.9% of the men reported either significant insomnia or short sleep. Symptoms of insomnia were related to symptoms of depression both among women and men (AOR 3.8, 95% CI 2.6-5.6 vs. AOR 1.9, 95% CI 1.1-3.2), while short sleep was related to depression among women (AOR 3.3, 95% CI 1.8-5.8), and to low education, poor health and a larger number of children among men. CONCLUSIONS The study showed that insomnia and sleep insufficiency are prevalent among women and men during pregnancy. The findings underline the impact of insomnia to both maternal and paternal health during pregnancy as well as to the implementation of effective interventions to prevent negative consequences of sleep disturbances.

Mitochondrial DNA Depletion and Deletions in Paediatric Patients with Neuromuscular Diseases: Novel Phenotypes

OBJECTIVE To study the clinical manifestations and occurrence of mtDNA depletion and deletions in paediatric patients with neuromuscular diseases and to identify novel clinical phenotypes associated with mtDNA depletion or deletions. METHODS Muscle DNA samples from patients presenting with undefined encephalomyopathies or myopathies were analysed for mtDNA content by quantitative real-time PCR and for deletions by long-range PCR. Direct sequencing of mtDNA maintenance genes and whole-exome sequencing were used to study the genetic aetiologies of the diseases. Clinical and laboratory findings were collected. RESULTS Muscle samples were obtained from 104 paediatric patients with neuromuscular diseases. mtDNA depletion was found in three patients with severe early-onset encephalomyopathy or myopathy. Two of these patients presented with novel types of mitochondrial DNA depletion syndromes associated with increased serum creatine kinase (CK) and multiorgan disease without mutations in any of the known mtDNA maintenance genes; one patient had pathologic endoplasmic reticulum (ER) membranes in muscle. The third patient with mtDNA depletion was diagnosed with merosine-deficient muscular dystrophy caused by a homozygous mutation in the LAMA2 gene. Two patients with an early-onset Kearns-Sayre/Pearson-like phenotype harboured a large-scale mtDNA deletion, minor multiple deletions and high mtDNA content. CONCLUSIONS Novel encephalomyopathic mtDNA depletion syndrome with structural alterations in muscle ER was identified. mtDNA depletion may also refer to secondary mitochondrial changes related to muscular dystrophy. We suggest that a large-scale mtDNA deletion, minor multiple deletions and high mtDNA content associated with Kearns-Sayre/Pearson syndromes may be secondary changes caused by mutations in an unknown nuclear gene.

Sleep apnea reduces the amount of computational deep sleep in the right frontopolar area in school-aged children

OBJECTIVE Obstructive sleep apnea (OSA) causes different symptoms in children, even though polysomnographic parameters that assess sleep quality may remain normal. Our spectral analysis of NREM sleep revealed local deep sleep reductions in adult OSA patients. We hypothesize that our method would also reveal local changes in pediatric OSA patients. METHODS Polysomnographies were part of a larger study evaluating snoring in school-aged children. All right-handed children with OSA with matched peers (n=10+10) were included. The median sleep depth (in Hz) and the amount of deep sleep <4Hz (DS%) were extracted for the whole NREM sleep time and for the first four NREM sleep episodes from frontopolar, central and occipital EEG-channels. RESULTS The main findings were that NREM sleep was lighter and DS% decreased in the right frontopolar area (p-values 0.034 and 0.019) in the OSA group when compared with the control group. CONCLUSION Local sleep quality changes might provide new insights to evaluate the effects of pediatric OSA as our method revealed a local computational deep sleep decrease in the right frontopolar area in the OSA group. SIGNIFICANCE The presented findings might implicate delayed local cortical development in childrens OSA, which may account for the cognitive problems found in pediatric OSA.

Variants in calcium voltage-gated channel subunit Alpha1 C-gene (CACNA1C) are associated with sleep latency in infants

Genetic variants in CACNA1C (calcium voltage-gated channel subunit alpha1 C) are associated with bipolar disorder and schizophrenia where sleep disturbances are common. In an experimental model, Cacna1c has been found to modulate the electrophysiological architecture of sleep. There are strong genetic influences for consolidation of sleep in infancy, but only a few studies have thus far researched the genetic factors underlying the process. We hypothesized that genetic variants in CACNA1C affect the regulation of sleep in early development. Seven variants that were earlier associated (genome-wide significantly) with psychiatric disorders at CACNA1C were selected for analyses. The study sample consists of 1086 infants (520 girls and 566 boys) from the Finnish CHILD-SLEEP birth cohort (genotyped by Illumina Infinium PsychArray BeadChip). Sleep length, latency, and nightly awakenings were reported by the parents of the infants with a home-delivered questionnaire at 8 months of age. The genetic influence of CACNA1C variants on sleep in infants was examined by using PLINK software. Three of the examined CACNA1C variants, rs4765913, rs4765914, and rs2239063, were associated with sleep latency (permuted P<0.05). There was no significant association between studied variants and night awakenings or sleep duration. CACNA1C variants for psychiatric disorders were found to be associated with long sleep latency among 8-month-old infants. It remains to be clarified whether the findings refer to defective regulation of sleep, or to distractibility of sleep under external influences.

Eveningness associates with smoking and sleep problems among pregnant women

ABSTRACT Sleep problems during pregnancy impair maternal health and increase the risk for adverse pregnancy outcome. The circadian preference toward eveningness has been associated with sleep problems in previous studies. Here, we studied whether evening-type women had more sleep problems during their pregnancy, as compared with other chronotypes, in a sample consisting of 1653 pregnant women from the Finnish CHILD-SLEEP Birth Cohort. Chronotype was assessed with a shortened version of the morningness–eveningness questionnaire. Pregnant evening-type women reported more sleep problems, including troubles of falling asleep (OR = 3.4, p < 0.0001), poor sleep quality (OR = 2.9, p < 0.01) and daily tiredness (OR = 3.2, p < 0.0001) than the morning-type women, even after controlling for sleep duration and sleep deprivation. They had higher scores on Epworth Sleepiness Scale (p < 0.05), Basic Nordic Sleep Questionnaire (p < 0.0001) and Global Seasonality Score (p < 0.01) and were also more often smokers, also during pregnancy (p < 0.001) and reported poorer general health (p < 0.001) than the morning-type women. They also reported having had more sleep problems during their childhood (OR = 1.5, p < 0.05) and adolescence (OR = 2.0, p < 0.001) than the morning-type women. Our results indicate that eveningness is associated with more sleep problems and unhealthy life habits during pregnancy.

The significance of supportive and undermining elements in the maternal representations of an unborn baby

Abstract Objective: The maternal representations of an unborn baby begin to develop during pregnancy. However, the factors that moderate them are not well identified. The objective of this study was to jointly explore supportive and undermining factors in the maternal representations of an unborn baby and motherhood. Methods: Cross-sectional data comprising 1646 women studied during the third trimester of pregnancy. Maternal expectations were measured using a 12-item self-report questionnaire, Mother’s Representations about an Unborn Baby. Depression, anxiety, family atmosphere and adult attachment were measured using standardised questionnaires. Statistical analysis is based on multivariate linear regression analysis. Results: The most powerful predictors of a mother’s prenatal expectations were the mother’s educational status, age, closeness in adult relationships, higher levels of depressive symptoms and family atmosphere. In accordance with our hypothesis, depression was related to the mother’s more negative expectations on their relationship with the unborn baby and on regularity in the baby’s sleeping and eating patterns. A positive family atmosphere and the mother’s ability for closeness and dependence (i.e. confidence) in adult relationships were related to more positive expectations of the mother–unborn baby relationship. On the other hand, stress, anxiety and adverse life events were not related to the mother’s expectations of her unborn baby. Conclusions: The results may be helpful in identifying families who need early professional support and call for studies where the prenatal phase is explored as a proactive phase for the development of the child–parent relationship.

Noncoding RET variants explain the strong association with Hirschsprung disease in patients without rare coding sequence variant

The pathogenesis of Hirschsprung disease is complex. Although the RET proto-oncogene is the most frequently affected gene in Hirschsprung disease, rare coding sequence variants explain only a small part of Hirschsprung disease cases. We aimed to assess the genetic background of Hirschsprung disease using a genome-wide association analysis combined with sequencing all RET exons in samples from 105 Hirschsprung disease cases (30 familial and 75 sporadic) and 386 controls. As expected, variants in or near RET showed the strongest overall association with Hirschsprung disease and the most statistically significant association was observed when using a recessive genetic model (rs2435357, NC_000010.10:g.43582056T > C; genotype TT, OR = 17.31, P = 1.462 × 10-21). Previously published associations in variants in SEMA (rs11766001, NC_000007.13:g.84145202A > C; allele C, OR = 2.268, P = 0.009533) and NRG1 (rs4541858, NC_000008.10:g.32410309A > G; allele G, OR = 1.567, P = 0.015; rs7835688, NC_000008.10:g.32411499G > C; allele C, OR = 1.567, P = 0.015) were also replicated in the genome-wide association analysis. Sequencing revealed a total of 12 exonic RET rare variants. Of these, eight amino acid changing rare variants and two frameshift variants caused or possibly caused Hirschsprung disease. Only a minority of the Hirschsprung disease cases (9/30 familial; 7/75 sporadic) carried one of the rare variants. Excluding the rare variant carriers from the genome-wide association analysis did not appreciably change the association of rs2435357 with Hirschsprung disease. We estimate that approximately two thirds of the sporadic cases may be statistically attributed to the recessive action of the common non-coding RET variants. Thus, even though most cases do not carry rare RET variants, combinations of rare variants and the common non-coding RET variant cause the majority of the cases in our population.

Behavioral Problems and Neurocognitive Functioning in Snoring School-Aged Children

2Department of Pediatrics, Tampere University Hospital, Tampere, Finland 3Department of Clinical Neurophysiology, Medical Imaging Centre, Pirkanmaa Hospital District, Tampere, Finland; School of Medicine, University of Tampere, Tampere, Finland *Corresponding author Kati Hagström, MS Psychology Clinic School of Social Sciences and Humanities University of Tampere Kalevantie 4, 33014 Tampere, Finland Tel. +358 3 355 111 Fax: +358 3 3551 7345 E-mail: hagstrom.kati.j@student.uta.fi