Pulmonary exacerbations are a cause of significant morbidity in patients with primary ciliary dyskinesia (PCD) and are frequently used as an outcome measure in clinical research into chronic lung diseases. So far, there has been no consensus on the definition of pulmonary exacerbations in PCD. 30 multidisciplinary experts and patients developed a consensus definition for children and adults with PCD. Following a systematic review, the panel used a modified Delphi process with a combination of face-to-face meetings and e-surveys to develop a definition that can be used in research settings for children and adults with PCD. A pulmonary exacerbation was defined by the presence of three or more of the following seven items: 1) increased cough, 2) change in sputum volume and/or colour, 3) increased shortness of breath perceived by the patient or parent, 4) decision to start or change antibiotic treatment because of perceived pulmonary symptoms, 5) malaise, tiredness, fatigue or lethargy, 6) new or increased haemoptysis, and 7) temperature >38°C. The consensus panel proposed that the definition should be used for future clinical trials. The definition should be validated and the usability assessed during these studies.

Primary ciliary dyskinesia (PCD) is a genetic, heterogeneous disease caused by dysfunction of cilia. Evidence is sparse and reports of lung function in PCD patients range from normal to severe impairment. This systematic review and meta-analysis of studies of lung function in PCD patients examines the spirometric indices of PCD patients and differences by age group and sex. We searched PubMed, Embase and Scopus for studies that described lung function in 10 or more patients with PCD. We performed meta-analyses and meta-regression to explain heterogeneity. We included 24 studies, ranging from 13 to 158 patients per study. The most commonly reported spirometric indices were forced expiratory volume in 1 s (FEV1) and forced vital capacity presented as mean and standard deviation of percent predicted values. We found considerable heterogeneity for both parameters (I 2=94-96%). The heterogeneity remained when we stratified the analysis by age; however, FEV1 in adult patients was lower. Even after taking into account explanatory factors, the largest part of the between-studies variance remained unexplained. Heterogeneity could be explained by genetic differences between study populations, methodological factors related to the variability of study inclusion criteria or details on the performance and evaluation of lung function measurements that we could not account for. Prospective studies therefore need to use standardised protocols and international reference values. These results underline the possibility of distinct PCD phenotypes as in other chronic respiratory diseases. Detailed characterisation of these phenotypes and related genotypes is needed in order to better understand the natural history of PCD.

Genetic association studies suggest a genetic predisposition for cisplatin-induced ototoxicity. Among other candidate genes, thiopurine methyltransferase (TPMT) is considered a critical gene for susceptibility to cisplatin-induced hearing loss in a pharmacogenetic guideline. The PanCareLIFE cross-sectional cohort study evaluated the genetic associations in a large pan-European population and assessed the diagnostic accuracy of the genetic markers. 1,112 pediatric cancer survivors who had provided biomaterial for genotyping were screened for participation in the pharmacogenetic association study. 900 participants qualified for inclusion. Based on the assessment of original audiograms, patients were assigned to three phenotype categories: no, minor, and clinically relevant hearing loss. Fourteen variants in eleven candidate genes (ABCC3, OTOS, TPMT, SLC22A2, NFE2L2, SLC16A5, LRP2, GSTP1, SOD2, WFS1, and ACYP2) were genotyped. The genotype and phenotype data represent a resource for conducting meta-analyses to derive a more precise pooled estimate of the effects of genes on the risk of hearing loss due to platinum treatment.

Assessing exposure to infections in early childhood is of interest in many epidemiological investigations. Because exposure to infections is difficult to measure directly, epidemiological studies have used surrogate measures available from routine data such as birth order and population density. However, the association between population density and exposure to infections is unclear. We assessed whether neighbourhood child population density is associated with respiratory infections in infants.

Chest wall abnormalities are a poorly studied complication after treatment for childhood cancer. Chest wall abnormalities are not well-described in the literature, and little is known on the impact on daily life of survivors.

COVID-PCD is a participatory study initiated by people with primary ciliary dyskinesia (PCD) who have an essential vote in all stages of the research from the design of the study to the recruitment of participants, and interpretation and communication of the study results. COVID-PCD aims to collect epidemiological data in real-time from people with PCD throughout the pandemic to describe incidence of coronavirus disease 2019 (COVID-19), symptoms and course of disease; identify risk factors for prognosis; and assess experiences, wishes and needs. The study is advertised through patient support groups and participants register online on the study website (www.covid19pcd.ispm.ch). The study invites persons of any age from anywhere in the world with a suspected or confirmed PCD. A baseline questionnaire assesses details on PCD diagnosis, habitual symptoms and COVID-19 episodes that occurred before study entry. Afterwards, participants receive a weekly follow-up questionnaire with questions on incident severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, current symptoms, social contact behaviour and physical activity. Occasional thematic questionnaires are sent out focussing on emerging questions of interest chosen by people with PCD. In case of hospitalisation, patients or family members are asked to obtain a hospital report. Results are continuously analysed and summaries put online. The study started recruitment on April 30, 2020, and 556 people with PCD completed the baseline questionnaire by November 2, 2020. The COVID-PCD study is a participatory study that follows people with PCD during the COVID-19 pandemic, helps to empower affected persons, and serves as a platform for communication between patients, physicians and researchers.

Spinal muscular atrophy (SMA) is an autosomal recessive disorder causing progressive proximal muscular, respiratory, and bulbar weakness. We present outcome data on motor function, ventilation, nutrition, and language development of SMA patients treated with nusinersen in Switzerland. This multicenter, observational study included 44 patients. At treatment initiation, after 2 months and then every 4 months we assessed motor function with the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND), Hammersmith Functional Motor Scale expanded (HFMSE) and 6-Minute Walk Test (6MWT). At treatment initiation, patients were 0.1-44.6 years old, treatment duration ranged from 6 to 41 months. All 11 SMA type 1 children achieved higher CHOP-INTEND scores at the last assessment compared to treatment initiation, 4 acquired stable sitting. Six type 1 children were <18 months-old at treatment initiation. Two of them did not need ventilation or nutritional support at the last assessment; three had delayed language development and 3 articulation difficulties. 5/21 SMA type 2 patients achieved higher HFMSE scores. All ambulant type 3 patients showed a gain in the 6MWT. Nusinersen is an effective treatment, with gains in motor function occurring particularly in children and SMA type 1, but also in type 2 and 3, adolescents and adults.

Primary ciliary dyskinesia (PCD) presents with symptoms early in life and the disease course may be progressive, but longitudinal data on lung function are scarce. This multinational cohort study describes lung function trajectories in children, adolescents and young adults with PCD. We analysed data from 486 patients with repeated lung function measurements obtained between the age of 6 and 24 years from the International PCD Cohort and calculated z-scores for forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio using the Global Lung Function Initiative 2012 references. We described baseline lung function and change of lung function over time and described their associations with possible determinants in mixed-effects linear regression models. Overall, FEV1, FVC and FEV1/FVC z-scores declined over time (average crude annual FEV1 decline was -0.07 z-scores), but not at the same rate for all patients. FEV1 z-scores improved over time in 21% of patients, remained stable in 40% and declined in 39%. Low body mass index was associated with poor baseline lung function and with further decline. Results differed by country and ultrastructural defect, but we found no evidence of differences by sex, calendar year of diagnosis, age at diagnosis, diagnostic certainty or laterality defect. Our study shows that on average lung function in PCD declines throughout the entire period of lung growth, from childhood to young adult age, even among patients treated in specialised centres. It is essential to develop strategies to reverse this tendency and improve prognosis.

Genotype-phenotype analyses of rare diseases often suffer from a lack of power, due to small sample size, which makes identifying significant associations difficult. Sinusoidal obstruction syndrome (SOS) of the liver is a rare but life-threatening complication of hematopoietic stem cell transplantation (HSCT). The alkylating agent busulfan is commonly used in HSCT and known to trigger SOS. We developed a novel pipeline to identify genetic determinants in rare diseases by combining in vitro information with clinical whole-exome sequencing (WES) data and applied it in SOS patients and controls.

Objectives: There is little data on SARS-CoV-2 in people with rare chronic diseases. We studied incidence and severity of SARS-CoV-2 and its risk factors in people with primary ciliary dyskinesia (PCD) from May 2020 to May 2022. Methods: We used self-reported questionnaire data from the COVID-PCD study at baseline or during weekly follow-ups. We studied factors associated with SARS-CoV-2 and symptoms using Poisson regression. Results: By May 2022, 728 people participated (40% male, median age 27 years; range 0-85). 87 (12%) reported SARS-CoV-2 at baseline or during follow-up and 62 people reported an incident SARS-CoV-2 infection during 716 person-years (incidence rate 9 per 100 person years). The strongest predictors for reporting SARS-CoV-2 were exposure during periods where Delta variant was dominant (IRR 4.52, 95% CI 1.92-10.6) and Omicron variants (IRR 13.3, 95% CI 5.2-33.8). Severity was mild; 12 (14%) were asymptomatic and 75 (86%) had symptoms among whom four were hospitalized. None needed intensive care and nobody died. Conclusion: The COVID-PCD study participants did not have a higher incidence of SARS-CoV-2 infections nor higher risk of severe COVID-19 disease than people from the general population.

Survival rates after childhood cancer now reach nearly 80% in developed countries. However, treatments that lead to survival and cure can cause serious adverse effects with lifelong negative impacts on survivor quality of life. Hearing impairment is a common adverse effect in children treated with cisplatin-based chemotherapy or cranial radiotherapy. Ototoxicity can extend from high-tone hearing impairment to involvement of speech frequencies. Hearing impairment can impede speech and language and neurocognitive development. Although treatment-related risk factors for hearing loss following childhood cancer treatment have been identified, the individual variability in toxicity of adverse effects after similar treatment between childhood cancer patients suggests a role for genetic susceptibility. Currently, 12 candidate gene approach studies have been performed to identify polymorphisms predisposing to platinum-induced ototoxicity in children being treated for cancer. However, results were inconsistent and most studies were underpowered and/or lacked replication.

Breastfeeding is said to protect children from eczema (atopic dermatitis), but the available evidence is conflicting and subject to the influences of parental atopy and reverse causation (when mothers extended duration of breastfeeding because their children had eczema).

Objectives: Primary ciliary dyskinesia (PCD) is a rare genetic disease that causes recurrent respiratory infections. People with PCD may be at high risk of severe COVID-19 and protection against SARS-CoV-2 is therefore important. We studied facemask usage and problems reported in relation with their use among people with PCD. Methods: We used data from COVID-PCD, an international observational cohort study. A questionnaire was e-mailed to participants in October 2020 that asked about facemask usage. Results: In total, 282 participants from 27 countries were included (Median age 32 years; 63% female). In total, 252 (89%) wore facemasks everywhere in public, 13 (5%) wore facemasks in most places, and 17 (6%) did not wear facemasks in public. Half of the participants reported that it was uncomfortable to wear facemasks because of runny nose, cough, or difficulty breathing. Participants less often wore facemasks when there was no national requirement. Conclusion: Most people with PCD wore facemasks despite frequent respiratory problems related to their use. Facemask usage was most frequent in countries with a national requirement emphasizing the importance of nationwide policies mandating facemasks.

Childhood cancer survivors are at high risk of long-term adverse effects of cancer and its treatment, including cardiac events. The pan-European PanCareSurFup study determined the incidence and risk factors for cardiac events among childhood cancer survivors. The aim of this article is to describe the methodology of the cardiac cohort and nested case-control study within PanCareSurFup.

Data on primary ciliary dyskinesia (PCD) epidemiology is scarce and published studies are characterised by low numbers. In the framework of the European Union project BESTCILIA we aimed to combine all available datasets in a retrospective international PCD cohort (iPCD Cohort).We identified eligible datasets by performing a systematic review of published studies containing clinical information on PCD, and by contacting members of past and current European Respiratory Society Task Forces on PCD. We compared the contents of the datasets, clarified definitions and pooled them in a standardised format.As of April 2016 the iPCD Cohort includes data on 3013 patients from 18 countries. It includes data on diagnostic evaluations, symptoms, lung function, growth and treatments. Longitudinal data are currently available for 542 patients. The extent of clinical details per patient varies between centres. More than 50% of patients have a definite PCD diagnosis based on recent guidelines. Children aged 10-19 years are the largest age group, followed by younger children (≤9 years) and young adults (20-29 years).This is the largest observational PCD dataset available to date. It will allow us to answer pertinent questions on clinical phenotype, disease severity, prognosis and effect of treatments, and to investigate genotype-phenotype correlations.

Survivors of childhood cancer are at risk of subsequent primary malignant neoplasms (SPNs), but the risk for rarer types of SPNs, such as oral cancer, is uncertain. Previous studies included few oral SPNs, hence large-scale cohorts are required to identify groups at risks.

Pediatric patients with cancer are at high risk for severe infections. Infections can trigger changes of vital signs long before clinical symptoms arise. Continuous recording may detect such changes earlier than discrete measurements. We aimed to assess the feasibility of continuous recording of vital signs by a wearable device (WD) in pediatric patients undergoing chemotherapy for cancer.

Survivors of childhood cancer have a higher mortality than the general population. We describe cause-specific long-term mortality in a population-based cohort of childhood cancer survivors. We included all children diagnosed with cancer in Switzerland (1976-2007) at age 0-14 years, who survived ≥5 years after diagnosis and followed survivors until December 31, 2012. We obtained causes of death (COD) from the Swiss mortality statistics and used data from the Swiss general population to calculate age-, calendar year-, and sex-standardized mortality ratios (SMR), and absolute excess risks (AER) for different COD, by Poisson regression. We included 3,965 survivors and 49,704 person years at risk. Of these, 246 (6.2%) died, which was 11 times higher than expected (SMR 11.0). Mortality was particularly high for diseases of the respiratory (SMR 14.8) and circulatory system (SMR 12.7), and for second cancers (SMR 11.6). The pattern of cause-specific mortality differed by primary cancer diagnosis, and changed with time since diagnosis. In the first 10 years after 5-year survival, 78.9% of excess deaths were caused by recurrence of the original cancer (AER 46.1). Twenty-five years after diagnosis, only 36.5% (AER 9.1) were caused by recurrence, 21.3% by second cancers (AER 5.3) and 33.3% by circulatory diseases (AER 8.3). Our study confirms an elevated mortality in survivors of childhood cancer for at least 30 years after diagnosis with an increased proportion of deaths caused by late toxicities of the treatment. The results underline the importance of clinical follow-up continuing years after the end of treatment for childhood cancer.

Healthy lifestyle including sufficient physical activity may mitigate or prevent adverse long-term effects of childhood cancer. We described daily physical activities and sports in childhood cancer survivors and controls, and assessed determinants of both activity patterns.

In epidemiological studies, childhood asthma is usually assessed with questionnaires directed at parents or children, and these may give different answers. We studied how well parents and children agreed when asked to report symptoms of wheeze and investigated whose answers were closer to measurable traits of asthma.