Mutações Do Gene Do Receptor De Vitamina D E Níveis Séricos De Vitamina D Em Crianças Com Asma

Abstract

Objective: To verify the relationship between polymorphisms of the vitamin D receptor gene (VDR), clinical findings, and serum vitamin D (VD) levels in asthmatics.Methods: A cross sectional study of 77 children aged 7 to 14 years old, who were attended at a specialized clinic. The children were divided into 3 groups: asthmatics who had been using inhaled corticosteroids (ICS) for more than one year; asthmatics who had not been using ICS; non-asthmatics, and children without allergies (according to the International Study of Asthma and Allergies in Childhood ­- ISAAC). Spirometry, skin prick tests, the presence of a VDR promoter CDX2 polymorphism from an allele-specific polimerase chain reaction (PCR), exons 2 and 3 polymorphisms genotyping by PCR-SSCA (single-strand conformational analysis), total immunoglobulin E (IgE) and specific IgE to mites and grass were evaluated in these three groups. Levels of 25-hydroxyvitamin D were determined in asthmatics only.Results: The mean age of the children was 10.8±2.0 years old, 57% were male, 38 were asthmatic and using ICS, 22 were asthmatic and not using ICS, and 17 were non-asthmatic. Allergic rhinitis was present in 90% of asthmatics. Homozygous CDX2 was detected in 23% of the patients and absent in the control group (p=0.03). Lower forced expiratory volume in 1 second (FEV1%) values were observed in CDX2 homozygous asthmatics (p=0.001). Variations in the exon 2 and 3 sequences were not related to asthma or the other tests. VD deficiency or insufficiency was detected in 98% of asthmatics. There was no association between VD levels and genetic polymorphisms from exons 2 and 3.Conclusions: There was a positive association between homozygous CDX2 polymorphism, asthma and lower FEV1% values. CDX2 is capable of modifying cell interaction between VDR and VD, and it could be associated with the prevalence of asthma, and the difficulty in controlling the disease.

Association of vitamin D gene polymorphisms in children with asthma - A systematic review

“…There were several other VDR polymorphisms analysed by several studies. Study done by Santos et al in the promoter region gene CDX2 and in Exons 2 and 3 showed significant association with asthmatic children [ 38 ] . Poon et al.…”

Дискуссионные Проблемы Генетического Полиморфизма Рецептора Витамина D При Бронхиальной Астме

“…The study findings prove that there are some discrepancies in the following receptor gene allele distribution: in the BA group -GG -28.3 %, GA -48.3 %, AA -23.3 %, in the control group -GG -29.4 %, GA -70.6 %, AA -0 %. That is, with the BA the AA allele variant's frequency is rising [16].…”

Vitamina D E Asma: Uma Relação Ainda Por Esclarecer

“…Two vitamin D deficiency situations have been traditionally identified: deficiency, defined as serum levels of 25(OH)D below 20 ng/mL and insufficiency, characterized by 25(OH)D levels between 20 and 30 ng/mL 2 . In the study by Santos et al, 98% of the children evaluated had inadequate vitamin D levels according to these criteria 4 . The current debates on the most appropriate reference levels of 25(OH)D are very important to aid in clinical interpretation of these findings.…”

“…The main finding of the study was the description of a new polymorphism (CDX2) in the vitamin D gene, which is associated with asthma in children. 4 In a recent meta-analysis, other polymorphisms were associated with asthma in children, but the findings vary depending on the ethnicity studied, 5 which reinforces the need for additional local studies on the subject.…”

“…Genetic evidence also associates asthma with vitamin D. Several genes linked to asthma may be regulated by vitamin D, and polymorphisms in the vitamin D receptors are associated with increased risk of developing the disease. 2 The present issue of Revista Paulista de Pediatria brings to you an interesting article by Santos et al 4 that addressed some aspects of the potential relationship between vitamin D and asthma. Vitamin D levels and vitamin D receptor polymorphisms have been assessed in two groups of asthmatics (with and without inhaled corticosteroid treatment) and compared with a control group.…”