Abstract
Vitamin D deficiency has been described in numerous chronic inflammatory diseases.
We sought to investigate vitamin D in children with asthma and its interaction with disease variables and inflammatory responses.
Methods: Thirty-nine children with asthma in a stable state were enrolled. Samples were obtained in summer. Lung function was measured on the same day. Serum concentrations of vitamin D were assayed with a radioimmunoassay kit, 30 healthy children acted as controls. CD4+ blood lymphocytes were investigated for cytokines expression (IFNg, IL4, IL10, IL17) by intracytoplasmic cytokines expression quantified by cytofluorometry. CD4+ CD25+FoxP3+ cells were identified as regulatory T cells.
Only 15% of our patients had a sufficient serum 25(OH) D ((33.83 + 3.31 ng/ml). Deficient values were observed in 43% of asthmatic patients (14.40 + 3.30; P = 0.0001). A positive correlation was found between FVC percent predicted and vitamin D (r = 0.35; P = 0.027). A negative correlation was observed between serum IL-17 and vitamin D (r = - 0.617; P = 0.001). Th1/Th2 ratios of controls were higher (27.26 + 14.35%) than those of patients (13.48 + 8.55%; P = 0.0001). In asthma, Th1/Th2 ratio was correlated with vitamin D (r= 0.68; P = 0.0001). Tr1/Th17 ratio was significantly decreased in asthmatic children. A positive correlation was observed between vitamin D and IL-10+ cells (r = 0.428; P = 0.008). A correlation was observed between the percentage of CD25+FoxP3+ Treg cells and vitamin D values in asthmatics (r = 0.368)
Conclusions: Asthma was associated with lower serum Vitamin D levels despite high levels of sun exposure. Our findings suggest that vitamin D is an important promoter of T cell regulation in vivo in asthma patients.
- © 2011 ERS