Dara O'Donoghue

A 3-D Well-Differentiated Model of Pediatric Bronchial Epithelium Demonstrates Unstimulated Morphological Differences Between Asthmatic and Nonasthmatic Cells

There is a need for reproducible and effective models of pediatric bronchial epithelium to study disease states such as asthma. We aimed to develop, characterize, and differentiate an effective, an efficient, and a reliable three-dimensional model of pediatric bronchial epithelium to test the hypothesis that children with asthma differ in their epithelial morphologic phenotype when compared with nonasthmatic children. Primary cell cultures from both asthmatic and nonasthmatic children were grown and differentiated at the air–liquid interface for 28 d. Tight junction formation, MUC5AC secretion, IL-8, IL-6, prostaglandin E2 production, and the percentage of goblet and ciliated cells in culture were assessed. Well-differentiated, multilayered, columnar epithelium containing both ciliated and goblet cells from asthmatic and nonasthmatic subjects were generated. All cultures demonstrated tight junction formation at the apical surface and exhibited mucus production and secretion. Asthmatic and nonasthmatic cultures secreted similar quantities of IL-8, IL-6, and prostaglandin E2. Cultures developed from asthmatic children contained considerably more goblet cells and fewer ciliated cells compared with those from nonasthmatic children. A well-differentiated model of pediatric epithelium has been developed that will be useful for more in vivo like study of the mechanisms at play during asthma.

Differential cytopathogenesis of respiratory syncytial virus prototypic and clinical isolates in primary pediatric bronchial epithelial cells

BackgroundHuman respiratory syncytial virus (RSV) causes severe respiratory disease in infants. Airway epithelial cells are the principle targets of RSV infection. However, the mechanisms by which it causes disease are poorly understood. Most RSV pathogenesis data are derived using laboratory-adapted prototypic strains. We hypothesized that such strains may be poorly representative of recent clinical isolates in terms of virus/host interactions in primary human bronchial epithelial cells (PBECs).MethodsTo address this hypothesis, we isolated three RSV strains from infants hospitalized with bronchiolitis and compared them with the prototypic RSV A2 in terms of cytopathology, virus growth kinetics and chemokine secretion in infected PBEC monolayers.ResultsRSV A2 rapidly obliterated the PBECs, whereas the clinical isolates caused much less cytopathology. Concomitantly, RSV A2 also grew faster and to higher titers in PBECs. Furthermore, dramatically increased secretion of IP-10 and RANTES was evident following A2 infection compared with the clinical isolates.ConclusionsThe prototypic RSV strain A2 is poorly representative of recent clinical isolates in terms of cytopathogenicity, viral growth kinetics and pro-inflammatory responses induced following infection of PBEC monolayers. Thus, the choice of RSV strain may have important implications for future RSV pathogenesis studies.

Chronic kidney disease and diabetes in the National Health Service: a cross-sectional survey of the UK National Diabetes Audit

We investigated the prevalence of chronic kidney disease and attainment of therapeutic targets for HbA1c and blood pressure in a large UK‐based diabetes population.

Obesity and kidney disease in type 1 and 2 diabetes: an analysis of the National Diabetes Audit

BACKGROUND Obesity is increasingly prevalent in many countries. Obesity is a major risk factor for the development of type 2 diabetes but its relationship with diabetic kidney disease (DKD) remains unclear. Some studies have suggested that the metabolic syndrome (including obesity) may be associated with DKD in type 1 diabetes. AIM To investigate the association between obesity and DKD. DESIGN Retrospective cross-sectional study. METHODS National Diabetes Audit data were available for the 2007-08 cycle. Type 1 and 2 diabetes patients with both a valid serum creatinine and urinary albumin:creatinine ratio were included. DKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2), albuminuria or both. Logistic regression was used to analyse associations of obesity (body mass index ≥30 kg/m(2)) and other variables including year of birth, year of diagnosis, ethnicity and stage of kidney disease. RESULTS A total of 58 791 type 1 and 733 769 type 2 diabetes patients were included in the analysis. After adjustment, when compared with type 1 diabetes patients with normal renal function those with DKD were up to twice as likely to be obese. Type 2 DKD patients were also more likely to be obese. For example, type 2 diabetes patients with an eGFR <15 ml/min/1.73 m(2) and normoalbuminuria, microalbuminuria or macroalbuminuria were all more likely to be obese; odds ratios (95% CI) 1.65 (1.3-2.1), 1.56 (1.28-1.92) and 1.27 (1.05-1.54), respectively. CONCLUSION This study has highlighted a strong association between obesity and kidney disease in type 1 diabetes and confirmed their association in type 2 diabetes.

Investigation of molecular markers in the diagnosis of refractory coeliac disease in a large patient cohort

Aims: Some patients with coeliac disease, despite strict adherence to a gluten-free diet, continue to have significant symptoms and/or a severe small intestinal histological lesion. The term “refractory coeliac disease” (rCD) is used to describe this condition. The purpose of this study was to investigate the value of tissue molecular markers reported to help in the diagnosis of rCD. Methods: Details on 61 patients with suspected rCD were collected. The clinical and laboratory findings in these patients were carefully evaluated, in part to determine whether patients were adhering to a strict gluten-free diet. The co-expression of CD3 and CD8 on intraepithelial lymphocytes was investigated by monoclonal antibody staining of small intestinal biopsy tissue; a finding of less than 50% CD3+ cells co-expressing CD8 was defined as an aberrant phenotype. T cell receptor gene rearrangement was assessed when a sufficient tissue sample was available. Results: A diagnosis of rCD was made in 38 patients based on clinical, laboratory and histological data. An aberrant intraepithelial lymphocyte population was found in 20 of these patients and in this group a clonal T cell population was found in five of seven patients tested. In the remaining 18 patients, the CD3/CD8 ratio was normal and two of seven tested had a clonal T cell population. After detailed monitoring, a diagnosis of rCD was excluded in the remaining 23 patients. Conclusions: This study supports the use of phenotypic and T cell clonality investigations in identifying patients with true rCD.

Night-to-night variation of pulse oximetry in children with sleep-disordered breathing

Background Sleep-disordered breathing is a common and serious feature of many paediatric conditions and is particularly a problem in children with Down syndrome. Overnight pulse oximetry is recommended as an initial screening test, but it is unclear how overnight oximetry results should be interpreted and how many nights should be recorded. Methods This retrospective observational study evaluated night-to-night variation using statistical measures of repeatability for 214 children referred to a paediatric respiratory clinic, who required overnight oximetry measurements. This included 30 children with Down syndrome. We measured length of adequate trace, basal SpO2, number of desaturations (>4% SpO2 drop for >10 s) per hour (‘adjusted index’) and time with SpO2<90%. We classified oximetry traces into normal or abnormal based on physiology. Results 132 out of 214 (62%) children had three technically adequate nights’ oximetry, including 13 out of 30 (43%) children with Down syndrome. Intraclass correlation coefficient for adjusted index was 0.54 (95% CI 0.20 to 0.81) among children with Down syndrome and 0.88 (95% CI 0.84 to 0.91) for children with other diagnoses. Negative predictor value of a negative first night predicting two subsequent negative nights was 0.2 in children with Down syndrome and 0.55 in children with other diagnoses. Conclusions There is substantial night-to-night variation in overnight oximetry readings among children in all clinical groups undergoing overnight oximetry. This is a more pronounced problem in children with Down syndrome. Increasing the number of attempted nights’ recording from one to three provides useful additional clinical information.

A difficult diagnosis in a pale child.

INTRODUCTION A previously healthy 4-year-old girl was referred to the emergency department with a history of abdominal pain, poor appetite, lethargy, and pallor. That morning she had vomited blood. She had previously been well. On examination, the child was pale with no evidence of lymphadenopathy, jaundice, or bruising. Initial investigations revealed a hypochromic, microcytic anemia. She was discharged after blood transfusion but later returned with anemia and shortness of breath. Subsequent investigations revealed that the child had diffuse alveolar hemorrhage. A discussion of the condition follows.