Vitamin D Receptor Gene Polymorphisms and Risk of Atopic Dermatitis in Chinese Han Population

Effect of weekly vitamin D supplementation on the severity of atopic dermatitis and type 2 immunity biomarkers in children: A randomized controlled trial

BACKGROUND

Vitamin D (VD) deficiency is common among patients with atopic dermatitis (AD) and often associated with severity. However, randomized trials of VD supplementation in AD have had equivocal results, and there is little information regarding the effect of VD supplementation on type 2 immunity in AD patients.

OBJECTIVES

To investigate the efficacy of VD supplementation to decrease severity of AD and to alter type 2 immunity biomarkers.

METHODS

We performed a randomized, double-blind, placebo-controlled trial. We randomly assigned 101 children with AD to weekly oral vitamin D3 (VD3) or placebo for 6 weeks. The primary outcome was the change in the Severity Scoring of AD (SCORAD).

RESULTS

Mean age of subjects was 6.3 ± 4.0 years, and baseline SCORAD was 32 ± 29. At baseline, 57% of children were VD deficient, with no difference between groups. Change in 25(OH)D was significantly greater with VD3 than placebo (+43.4 ± 34.5 nmol/L vs. +2.3 ± 21.2 nmol/L, p < 0.001). SCORAD change at 6 weeks was not different between VD and placebo (-5.3 ± 11.6 vs. -5.5 ± 9.9, p = 0.91). There were no significant between-group differences in change of eosinophil counts, total IgE, Staphylococcal enterotoxin specific IgE, CCL17, CCL22, CCL27, LL-37 or Staphylococcus aureus lesional skin colonization. Vitamin D receptor (VDR) gene single nucleotide polymorphisms FokI, ApaI and TaqI did not modify subjects' response to VD supplementation.

CONCLUSIONS

Among children with AD, weekly VD supplementation improved VD status but did not modify AD severity or type 2 immunity biomarkers compared to placebo (ClinicalTrials.gov NCT01996423).

The Association of Vitamin D Receptor Gene Polymorphisms with Vitamin D, Total IgE, and Blood Eosinophils in Patients with Atopy

BACKGROUND

In order to improve the control of atopic diseases, it is important to clarify the pathogenesis of atopy and identify its various triggers. Single nucleotide polymorphisms (SNPs) of the vitamin D receptor gene (VDR) may impact atopy. The aim of this study was to investigate the possible associations between VDR SNPs and vitamin D, total IgE, and eosinophils in atopy.

METHODS

In total, 203 adults, including 122 patients with atopic diseases (45 with atopic dermatitis, 77 with allergic asthma) and 81 healthy controls, were involved in the study. The blood eosinophil count was determined with an automated hematology analyzer. Vitamin D and total immunoglobulin E (IgE) levels were evaluated using the ELISA method. Polymorphisms in the VDR gene were analyzed with real-time PCR using TaqMan probes.

RESULTS

We analyzed six VDR single nucleotide polymorphisms and found a significant association between VDR rs731236 GG genotype and normal vitamin D levels in atopic patients and healthy subjects (OR 11.33; 95% CI: 1.049-122.388 and OR 4.04; 95% CI: 1.117-14.588, respectively, p < 0.05). Additionally, the study results revealed a significant relationship between the VDR rs2228570 GG genotype and normal vitamin D levels in patients with atopy and healthy subjects (OR 3.80; 95% CI: 1.190-12.134 and OR 2.09; 95% CI: 1.044-4.194, respectively, p < 0.05). The rs2228570 allele A was associated with decreased vitamin D levels in patients with atopy and healthy subjects (OR 0.28; 95% CI: 0.098-0.804 and OR 0.229; 95% CI: 0.069-0.761, respectively, p < 0.05). The VDR rs3847987 genotypes AA and AC were significantly associated with normal vitamin D levels in healthy subjects (OR 35.99; 95% CI: 6.401-202.446 and OR 4.72; 95% CI: 1.489-15.007, respectively, p < 0.05). In addition, a decreased amount of vitamin D was associated with atopic diseases such as atopic dermatitis and allergic asthma (OR 0.49; 95% CI: 0.439-1.308 and OR 0.58; 95% CI: 0.372-0.908, respectively, p < 0.05). The rs11168293 allele T was associated with the normal range of total IgE in atopy (OR 2.366; 95% CI: 1.133-5.027; p < 0.05). Significant associations were found between VDR rs731263 allele G, rs11168293 allele G, and increased blood eosinophil levels in patients with atopy (OR 0.319; 95% CI: 0.163-0.934 and OR 0.323; 95% CI: 0.112-0.935, respectively, p < 0.05).

CONCLUSIONS

A decreased vitamin D level showed a significant relationship with atopic diseases (atopic dermatitis and allergic asthma). The association between the VDR gene polymorphisms rs2228570, rs731236, and rs11168293 and vitamin D, total IgE, and blood eosinophils in patients with atopy suggested that VDR polymorphisms and the vitamin D level should be considered when examining the factors associated with atopy.

The relationship between single nucleotide polymorphisms and skin cancer susceptibility: A systematic review and network meta-analysis

Background

Single nucleotide polymorphisms (SNPs) interfere with the function of certain genes and thus may influence the probability of skin cancer. The correlation between SNPs and skin cancer (SC) lacks statistical power, however. Therefore, the purpose of this study was to identify the gene polymorphisms involved in skin cancer susceptibility using network meta-analysis and to determine the relationship between SNPs and SC risk.

Methods

PubMed, Embase, and Web of Science were searched for articles including "SNP" and different types of SC as keywords between January 2005 and May 2022. The Newcastle-Ottawa Scale was used to assess bias judgments. The odds ratio (ORs) and their 95% confidence intervals (CIs) were determined to estimate heterogeneity within and between studies. Meta-analysis and network meta-analysis were carried out to identify the SNPs associated with SC. The P-score of each SNP was compared to obtain the rank of probability. Subgroup analyses were performed by cancer type.

Results

A total of 275 SNPs from 59 studies were included in the study. Two subgroup SNP networks using the allele model and dominant model were analyzed. The alternative alleles of rs2228570 (FokI) and rs13181 (ERCC2) were the first-ranking SNPs in both subgroups one and two of the allele model, respectively. The homozygous dominant genotype and heterozygous genotype of rs475007 in subgroup one and the homozygous recessive genotype of rs238406 in subgroup two were most likely to be associated with skin cancer based on the dominant model.

Conclusions

According to the allele model, SNPs FokI rs2228570 and ERCC2 rs13181 and, according to the dominant model, SNPs MMP1 rs475007 and ERCC2 rs238406 are closely linked to SC risk.