Steroid requirements and immune associations with vitamin D are stronger in children than adults with asthma

Abstract

Background the effects of serum vitamin D status on atopy, steroid requirement and functional responsiveness to corticosteroids in children vs. adults with asthma have not been studied systematically. Objective to explore age-specific effects of vitamin D in asthma. Methods serum vitamin D levels were examined in a prospective study of adults and children (102 normal controls and 103 asthmatics). Peripheral blood mononuclear cells (PBMC) were cultured for 3h +/−100nM dexamethasone (DEX) and the expression of corticosteroid-regulated genes was detected by real time PCR. Serum IgE levels were measured; information about asthmatics’ steroid requirement was collected. Results 47.6% of asthmatics and 56.8% normal control subjects had deficient serum vitamin D levels (<20ng/ml) with mean ± SD of 20.7±9.8ng/ml and 19.2±7.7ng/ml, respectively. In multivariate regression models, a significant positive correlation between serum vitamin D and the expression of vitamin D regulated targets - cyp24a by PBMC (p=0.0084, pediatric asthma group only) and serum LL-37 levels (p=0.0006, pediatric; but p=0.0067 in adult asthma groups) was found. An inverse association between vitamin D and serum IgE levels was observed in the pediatric (p=0.006) asthma group. Serum vitamin D (p=0.05) as well as PBMC cyp24a expression (p=0.0312) demonstrated significant inverse relationship with daily ICS dose in the pediatric asthma group only. Cyp24a expression in PBMC correlated positively with in vitro suppression of TNFα (p=0.05) and IL-13 (p=0.0094) in PBMC by DEX only in the pediatric asthma group. Conclusions this study demonstrated significant associations between serum vitamin D status and steroid requirement and in vitro responsiveness to corticosteroids in the pediatric but not the adult asthma group. Vitamin D was also related to IgE levels in children but not in adults. Clinical Implication The results of this study suggest that vitamin D supplementation in children may enhance corticosteroid responses, control atopy and could thereby improve asthma control.

Serum 25-hydroxyvitamin D levels do not correlate with asthma severity in a case-controlled study of children and adolescents

“…A third case-control study involving children and adults reported a non-significant difference in 25(OH)D levels between 103 asthmatic patients and 102 controls. This study, however, showed a significant inverse association between vitamin D and serum IgE, as well as vitamin D and daily inhaled corticosteroid dose in the pedia tric asthma group only (17) . Among the non casecontrol studies that reported significant inverse correlation with asthma severity, one study evaluated 616 asthmatic patients (13) , another studied 75 asthmatic patients (14) , whereas a third study investigated 86 asthmatic patients (16) .…”

“…Goleva et al (17) reported a significant inverse correlation between serum IgE and serum vitamin D levels in pediatric patients with asthma but not in adult asthmatic patients. They also found significant associations between serum vitamin D levels and vitamin D-regulated targets and the patients ' steroid responses in vitro, as well as steroid requirements in pediatric asthmatic patients but not in the adult asthmatic patients.…”

Enhanced production of IL-17A in patients with severe asthma is inhibited by 1α,25-dihydroxyvitamin D3 in a glucocorticoid-independent fashion

“…Several studies have pointed out striking links in populations between vitamin D deficiency and asthma severity or requirements for anti-inflammatory medication (27)(28)(29)(30). In previous studies investigating the immunological basis of this relationship, we have shown that 1 α,25-dihydroxyvitamin D3…”

“…This arises in part from studies demonstrating that patients with poorly controlled asthma and/or poor responsiveness to corticosteroid have significantly reduced vitamin D, at least as assessed by the circulating precursor 25-hydroxyvitamin D3 (27)(28)(29)(30)47). We and others have previously demonstrated an association with 25(OH)2D3 status and airways smooth muscle mass (27,28,48).…”

Ефективність Застосування Вітаміну D У Дітей, Хворих На Бронхіальну Астму Та Атопічний Дерматит

“…Дефіцит ві-таміну D сприяє розвитку БА в дітей [7]. Зниження рівня 25(OH)D 3 у крові пов'язане з більш високими шансами загострення БА [3].…”