Laurence Hanssens

Ataluren (PTC124) induces cystic fibrosis transmembrane conductance regulator protein expression and activity in children with nonsense mutation cystic fibrosis.

RATIONALE Nonsense (premature stop codon) mutations in mRNA for the cystic fibrosis transmembrane conductance regulator (CFTR) cause cystic fibrosis (CF) in approximately 10% of patients. Ataluren (PTC124) is an oral drug that permits ribosomes to readthrough premature stop codons in mRNA to produce functional protein. OBJECTIVES To evaluate ataluren activity, safety, and pharmacokinetics in children with nonsense mutation CF. METHODS Patients were assessed in two 28-day cycles, comprising 14 days on and 14 days off ataluren. Patients took ataluren three times per day (morning, midday, and evening) with randomization to the order of receiving a lower dose (4, 4, and 8 mg/kg) and a higher dose (10, 10, and 20 mg/kg) in the two cycles. MEASUREMENTS AND MAIN RESULTS The study enrolled 30 patients (16 male and 14 female, ages 6 through 18 yr) with a nonsense mutation in at least one allele of the CFTR gene, a classical CF phenotype, and abnormal baseline nasal epithelial chloride transport. Ataluren induced a nasal chloride transport response (at least a -5-mV improvement) or hyperpolarization (value more electrically negative than -5 mV) in 50% and 47% of patients, respectively, with more hyperpolarizations at the higher dose. Improvements were seen in seven of nine nonsense mutation genotypes represented. Ataluren significantly increased the proportion of nasal epithelial cells expressing apical full-length CFTR protein. Adverse events and laboratory abnormalities were infrequent and usually mild. Ataluren pharmacokinetics were similar to those in adults. CONCLUSIONS In children with nonsense mutation CF, ataluren can induce functional CFTR production and is well tolerated.

Basophil activation tests for the diagnosis of food allergy in children

Background Positive skin prick tests (SPT) for food allergens and specific IgE (sIgE) in serum indicate sensitization but do not enable distinction between sensitized but tolerant and clinically allergic patients.

Gender differences in inflammatory markers in children.

No clear explanation exists to understand how sex hormones and/or chromosomes affect the immune system. In vitro studies of human lymphoid cells also show sex differences in immune function. To evaluate these differences in frequent pediatric emergencies, we analyze the expression of inflammatory markers (C-reactive protein, erythrocyte sedimentation rate, and neutrophil count) underlying inflammatory processes in children: 482 children (241 girls and 241 boys) hospitalized for pneumonia (n = 384), pyelonephritis (n = 39), or bronchiolitis (n = 59) matched for age and sex. All patients were younger than 10 years. A control population of 97 children (50 girls and 47 boys) admitted for day surgery (tonsillectomy, circumcision, or strabismus) was included. We observed highly significant differences between girls and boys: median C-reactive protein concentration of 5.45 mg/dL (range, 0.2-36.0 mg/dL) for girls and 2.6 mg/dL (range, 0.3-37.3 mg/dL) for boys (P < 0.0001), and median erythrocyte sedimentation rate of 39.5 mm/h (range, 2-104 mm/h) for girls and 24 mm/h (range, 4-140 mm/h) for boys (P < 0.005). Neutrophil counts were also significantly different: a median of 8,796 cells/&mgr;L (range, 328-27,645 cells/&mgr;L) for girls and 6,774 cells/&mgr;L (range, 600-38,668 cells/&mgr;L) for boys (P < 0.02). The duration of fever after initiating antibiotic therapy was longer in girls than in boys, but there was no difference (Fisher exact test, P < 0.06). The present study documents a relationship between sex and both the production of inflammatory markers and neutrophil recruitment. Sex difference also showed more direct clinical relevance with associations seen between sex and both duration of fever and duration of disease (bronchiolitis P < 0.0007).

Gender differences and inflammation: an in vitro model of blood cells stimulation in prepubescent children

BackgroundGender influences clinical presentations and markers in inflammatory diseases. In many chronic conditions, frequency of complications is greater in females, suggesting that continuous inflammatory reaction may induce greater damage in targeted organs and functions.MethodsTo investigate gender dimorphism at a cellular level, we evaluated the production of cytokines implicated in inflammatory processes (IL -1, IL- 6, PGE-2 and TNF alpha), in healthy prepubescent children of both sex and Turners syndrome (TS) patients (genotype XO). We used stimulation by LPS (0.2 and 1 ng/ml) and Pokeweed Mitogen (PWM) on overnight cultures from whole blood samples, collected in 57 subjects: 22 girls/26 boys (5-96 months), and 9 TS patients (6-15 years). The primary outcome was to evaluate if gender influences the production of cytokines, with potential relation to X chromosome monosomy. Secondary endpoints were to relate different cytokines level productions and conditions.ResultsWe confirm the male over female increased cytokine productions already observed in adults. This is contrasting with numerous observations obtained in vivo about increased production of inflammatory markers in females (CRP, ESR and neutrophil counts), as we recently reported in children. Relative variations of the dimorphism according to stimulus, its concentration and cytokine type are discussed, presenting IL6 with a modulating function that could be more potent in males. TS subjects follow mostly the male pattern of reactivity, sustaining the role of some gene expression differing with X chromosome monosomy and disomy.ConclusionsPersistence of the latter dimorphism throughout life casts doubts on its direct relationship with individual hormonal status, as already documented by others in vitro, and supports the need for alternative hypothesis, such as the influence of X chromosome gene products escaping X inactivation in females and absent in subjects with X monosomy (males, TS).

Severe Gastritis in an Insulin-dependent Child With an IPEX Syndrome

Gastric mucosal atrophy is a rare finding in children and it is seldom seen even in association with Helicobacter pylori infection (1). Atrophic gastritis predisposing to gastric tumours is observed in 20% of patients with autoimmune type 1 insulin-dependent diabetes mellitus (IDDM) patients with parietal cell antibodies (2). Evidence for type 1 diabetes being an autoimmune process is based on the presence of ‘‘diabetes autoantibodies’’ (3). The role of CD4þCD25þ regulatory T cells in protecting against a variety of autoimmune diseases is admitted (4). Autoimmune gastritis is a disease caused by a CD4þT cell response to the gastric Hþ/Kþ-ATPase encoded by Atp4a and Atp4b Hþ/Kþ-ATPase. In recent experimental work on mice, it is proposed that prevention of autoimmune gastritis requires extrathymic T cell deletion and suppression by regulatory T cells (5). We report the case of a boy with early IDDM who developed an extensive exfoliative gastritis progressing toward mucosal atrophy with intestinal and malpighian metaplasia. An attenuated form of immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX) was eventually confirmed by FoxP3 mutation.

Sampling and decontamination method for culture of nontuberculous mycobacteria in respiratory samples of cystic fibrosis patients

ABSTRACT We confirmed that chlorhexidine decontamination yielded more nontuberculous mycobacteria than did the N-acetyl-l-cysteine-NaOH-oxalic acid procedure from respiratory samples of cystic fibrosis patients on solid cultures. However, this improved recovery is mostly balanced if the latter is combined with liquid culture. Furthermore, none of the 145 cough swabs, used to sample young children, cultured positive, suggesting that swabs are low-quality samples.

Chronic inflammatory diseases in children are more severe in girls.

In humans and animal models, females express higher immune reactivity and more robust inflammatory responses. We analyzed the expression of current inflammatory markers in 149 children (74 girls and 75 boys) with three chronic inflammatory diseases: 50 with asthma, 47 with cystic fibrosis, and 52 with sickle cell anemia to evaluate the potential differences in clinical response according to sex. Data including temperature, neutrophil count (NC), and C-reactive protein were recorded for each patient at several time points according to his/her disease. In asthma, NC was higher in girls than in males (P < 0.02), as were doses of cortisone (P < 0.04) or inhaled bronchodilators (P < 0.01) received at recovery. In cystic fibrosis, NC became significantly higher in girls at age 5 years (P < 0.003), whereas episodes of infection and antibiotic administration were already significantly more frequent in girls at age 2 years (P < 0.02 and P < 0.05, respectively). In sickle cell anemia, the number of crises since diagnosis and number of acute chest syndrome episodes were significantly higher in girls (P < 0.01 and P < 0.05, respectively). Our study extends the documentation of a relationship between sex, inflammatory markers, and clinical outcome in prepubescent children, suggesting a genetic predetermination is more likely than hormonal influence.

Reduction of the Six-Minute Walk Distance in Children with Sickle Cell Disease Is Correlated with Silent Infarct: Results from a Cross-Sectional Evaluation in a Single Center in Belgium

Background The 6-minute walk test (6MWT) is used in adults and children affected by a wide range of chronic diseases to evaluate their sub-maximal exercise capacity. It reflects the global response of various physiological systems in a situation simulating a daily life activity. Methods We analyzed factors affecting the 6MWT in 46 Sickle Cell Disease children. Forty-two were treated with hydroxyurea (HU). Patients with normal test (>80% of the age-standardized predicted value) were compared to patients with abnormal test (≤80%). Baseline hematological values, clinical events, cerebrovascular disease, cardio-pulmonary parameters and disease-modifying treatment were compared according to the performance of the test. Results Among the 46 patients, 14 had an abnormal 6MWT. In univariate analysis, both groups were similar for biological and clinical data. Six of the 14 patients with an abnormal 6MWT had silent infarct (SI) compared to 6/32 with a normal test (P = 0.09). When excluding chronically transfused patients, 4 of the 11 patients with an abnormal 6MWT had SI compared to 1/26 (P = 0.02). Baseline pulse oximetry was normal in both groups but slightly lower in patients with abnormal 6MWT (P = 0.02). No patient presented exercise-induced desaturation. In multivariate analysis, the only factor associated with abnormal 6MWT was the presence of SI (P = 0.045). Conclusions In our cohort of 46 patients characterized by high exposure rate to HU and by the absence of severe cardiopulmonary disease, the sole factor independently associated with 6MWT was the presence of SI. The lower exercise capacity of children with SI may reflect some subclinical neurological impairment as they do not differ by hemoglobin level or cardiopulmonary parameters.

The clinical benefits of long-term supplementation with omega-3 fatty acids in cystic fibrosis patients – A pilot study

Effectiveness of omega-3 supplementation in cystic fibrosis (CF) remains controversial. This study sought to evaluate clinical status, exercise tolerance, inflammatory parameters, and erythrocyte fatty acid profile after 1 year of oral omega-3 supplementation in CF patients. Fifteen ΔF508-homozygous patients undergoing chronic azithromycin were randomized to receive omega-3 fish oil supplementation at a dose of 60mg/Kg/day or placebo. In comparison with the previous year, in the supplemented group, the number of pulmonary exacerbations decreased at 12 months (1.7 vs. 3.0, p<0.01), as did the duration of antibiotic therapy (26.5 days vs. 60.0 days, p<0.025). Supplementation significantly increased the levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as early as <3 months of administration, with concomitant decreases in arachidonic acid (AA) levels. This pilot study suggests that long-term omega-3 supplementation offers several clinical benefits as to the number of exacerbations and duration of antibiotic therapy in CF patients.

ePS05.9 Benefits of long-term supplementation with omega-3 polyunsaturated fatty acids in cystic fibrosis

Clinical symptoms and lung function of CF may be influenced by correcting essential fatty acids (EFA) deficiency. Nevertheless, the value of EFA supplementation in CF remains controversial. Objectives The aim of this longitudinal randomized double-blind placebo-controlled clinical trial was to assess the benefits of an oral supplementation with omega-3 on clinical and nutritional status, lung function and exercise tolerance. Methods A supplementation with a triglyceride source of omega-3 (Omega 3 Premium®, Laboratoires Ponroy, France) at a daily dose of 60 mg/kg during 1 year was administered to ΔF508 homozygous CF patients above 5 years of age. Patients were assessed at 3, 6, 9 and 12 months. Lung function was performed at each visit and an exercise test before and at the end of study. Results Of the 16 patients included, 13 completed the study. Six received omega-3 and 7 the placebo. Compared to the control group the cumulative duration of antibiotic therapy decreased in the intervention group at 9 months (24.5 days vs 46.0 days, p=0.02) and at 12 months (26.5 days vs 65.0 days, p Conclusions This longitudinal randomized placebo-controlled study shows some clinical benefits of long-term omega-3 supplementation in CF patients. However, additional studies with larger populations are needed. Supported by a grant from the Belgian Cystic Fibrosis Association.