Long-term outcomes in paediatric asthma

Inhaled corticosteroid-phobia and childhood asthma: Current understanding and management implications

Asthma is the most prevalent chronic disease in children. Inhaled corticosteroids (ICS) is the first-line controller therapy for children with persistent asthma, however, suboptimal compliance to ICS therapy remains as a major obstacle in paediatric asthma management. Steroid-phobia, the fear of side-effects and subsequent aversion of ICS, has been widely reported in parents of asthmatic children. The reported prevalence of steroid-phobia varies widely from 19% to 67% in different populations. The concerns about ICS frequently raised by parents include growth suppression, weight gain, bone weakness, addiction and psychiatric disturbances. Outside of growth suppression, which is statistically significant yet mild in clinical studies, the other concerns are not evidence-based and are misconceptions. Conflicting results have been reported regarding the impact of steroid-phobia on ICS compliance. In contrast, steroid-phobia has consistent and negative effects on asthma control in children. While asthma educational programmes have demonstrable benefits in general paediatric populations, the generalisability of such programmes to steroid-phobic parents remains undetermined. There is a paucity of data on specific educational programmes to clear misconceptions and reduce steroid-phobia. Given the continually raising prevalence of paediatric asthma, high-quality studies are warranted to investigate the prevalence and impact of steroid-phobia, with an ultimate goal of developing effective strategies to tackle steroid-phobia and improve asthma care in children.

Effects of inhaled ciclesonide and fluticasone propionate on cortisol secretion and airway responsiveness to adenosine 5'monophosphate in asthmatic patients

The efficacy and systemic effects of ciclesonide, a novel glucocorticosteroid, inhaled via pressurized metered-dose inhaler (pMDI) were compared with fluticasone propionate pMDI in 26 patients with asthma, using a randomized, double blind, placebo-controlled, double dummy, 6-period crossover study design. Treatments were placebo, ciclesonide 320 microg (ex-actuator dose) once daily (o.d.), ciclesonide 640 microg o.d., ciclesonide 640 microg twice daily (b.i.d.), fluticasone propionate 440 microg (ex-actuator dose) b.i.d., and fluticasone propionate 880 microg b.i.d. The primary variable was area under the plasma cortisol concentration-time curve over 24 h (plasma cortisol AUC(0-24), relative to placebo) derived from samples taken every 2 h, on the 9th day of treatment. Secondary variables were 24-h urinary cortisol excretion and PC20 for adenosine 5'-monophosphate (AMP) (relative to placebo and expressed in doubling concentrations). Ciclesonide did not affect 24-h cortisol secretion. Fluticasone propionate suppressed cortisol secretion as demonstrated by a decrease in plasma cortisol AUC(0-24), relative to placebo, by 29% (95% CI 15-41) and 59% (95% CI 51-66) with 440 and 880 microg b.i.d., respectively. PC20 more than doubled with each active treatment, but no statistically significant dose-response effect could be established. It was concluded that moderate to high doses of fluticasone propionate suppressed cortisol secretion, that ciclesonide did not suppress cortisol secretion, and that all active treatments decreased hyperresponsiveness to AMP.

Epithelial stress and structural remodelling in childhood asthma

BACKGROUND

In adult asthma the bronchial epithelium shows high expression of the epidermal growth factor receptor (EGFR) and the cyclin dependent kinase inhibitor, p21waf, linked to ongoing stress and injury.

METHODS

To determine if these are early markers of disease, sections of bronchial specimens obtained post mortem or by bronchoscopy from non-asthmatic (n = 7), moderate (n = 7), or severe (n = 9) asthmatic children aged 5-15 years were examined immunohistochemically. All severe and one moderately asthmatic children were receiving inhaled corticosteroids.

RESULTS

The lamina reticularis of the asthmatic biopsy sections was found to be thicker (p = 0.01) than normal with increased deposition of collagen III (p = 0.007); submucosal eosinophil numbers did not differ between groups. As in adults, there was an asthma-related increase in epithelial EGFR (p<0.002) but there was no evidence of proliferation, with Ki67 being reduced (p = 0.001) and p21waf increased (p<0.004). The thickness of the lamina reticularis was significantly correlated with epithelial EGFR (rho = 0.77, p<0.001).

CONCLUSIONS

These data provide evidence that, in asthmatic children, the epithelium is stressed or injured without significant eosinophilic inflammation. This change in the epithelial phenotype is associated with collagen deposition in the lamina reticularis, suggesting that the epithelial mesenchymal trophic unit is active early in, and may contribute to, the pathogenesis of asthma.

Biochemical markers of bone metabolism and calciuria with inhaled budesonide therapy

We investigated the changes in renal excretion of calcium, sodium, and potassium in asthmatic children treated with inhaled budesonide, an inhaled glucocorticoid. Twenty-two asthmatic patients (7 female, 15 male, mean age 10.1+/-4.3 years) treated with 400-600 microg/day inhaled budesonide and 23 healthy children (6 female, 17 male, mean age 10.2+/-2.8 years) were enrolled in the study. The parameters recorded were serum sodium, potassium, calcium, phosphorus, alkaline phosphatase (ALP), type I collagen carboxyterminal telopeptide (ICTP), osteocalcin, intact parathyroid hormone (PTH) levels, first spot morning urine calcium/creatinine ratio, sodium/potassium ratio, and daily renal calcium excretion rate (UCa-ER). These parameters were measured in the control group and pre- and post-budesonide treatment in asthmatic children. Serum electrolytes, ALP, PTH, ICTP, and UCa-ER were in the normal ranges and were not significantly different between controls and asthmatic children. Serum levels of ICTP increased, while levels of osteocalcin decreased after budesonide therapy in the asthmatic group ( P=0.001, P=0.005). UCa-ER was decreased after budesonide therapy in asthmatics ( P=0.000). In conclusion, moderate doses of inhaled budesonide cause hypocalciuria and decreased bone turnover. These results may be attributed to a mechanism compensating for decreased absorption of calcium in the gut due to the topical effect of swallowed budesonide rather than the systemic effects of the drug. Increased bone metabolism and decreased turnover may have an important role in this compensatory mechanism.

Efficacy of steroid treatments in the asthmatic preschool child

Asthma represents the most common chronic disease in preschool children. Hospital admission for wheezy disorders is the most common paediatric chronic disease causing hospital admission and more common in young children than later in life.