Relationship of vitamin D receptor gene polymorphisms in Helicobacter pylori gastric patients

Vitamin D and Its Association with H. pylori Prevalence and Eradication: A Comprehensive Review

Taking into account previous data that sustain a relationship between vitamin D deficiency and higher H. pylori infection positivity rates, this review aims to assess the influence of vitamin D deficiency and/or insufficiency upon the prevalence of H. pylori infection and its eradication success. Three major databases were searched for articles that analyzed a relationship between vitamin D status and H. pylori infection. The literature search retrieved a total of 37 reports, after the article selection process. Hypovitaminosis D emerged as a potential risk factor for H. pylori infection, given the higher prevalence of vitamin D deficiency and/or insufficiency among H. pylori-positive subjects. Furthermore, the same type of micronutrient deficiency has been directly linked to H. pylori eradication failure. An inverse linear relationship between vitamin D status and gastric cancer risk exists, but the additional involvement of H. pylori in this correlation is still in question. The potential benefit of oral supplements in enhancing the success of classical therapeutic regimens of H. pylori still requires future research. Future population-based studies from larger geographical areas are warranted to address this subject in more depth.

Association Between Vitamin D Receptor Polymorphism and the Response to Helicobacter Pylori Treatment

Background & Aims

This research aimed to determine how variations in the vitamin D receptor gene affected the response of H. pylori infections to eradication therapy.

Patients and Methods

On 105 adult H. Pylori-positive patients, a prospective cohort study was carried out. PCR was used to genotype all patients' VDR gene polymorphisms. The patients in the study received standard triple eradication medication (clarithromycin 500 mg, amoxicillin 1000 mg, and omeprazole 20 mg) twice daily for 14 days. A stool test for H. pylori Ag was conducted 4 weeks following the end of treatment.

Results

In our study, the usual triple therapy's H. pylori eradication rate was 75.2%. The successful eradication of H. pylori and VDR rs 2228570 gene polymorphisms was more prevalent in CT gene polymorphism (64.6%) compared to non-responders (19.2%), while treatment failure was more prevalent in CC gene polymorphism (73.1% in non-responders compared to responders 24.1%), which is statistically significant. In regards to the eradication of H. pylori and VDR rs7975232 gene polymorphisms, the success of eradication was more prevalent in AC gene polymorphism (54.4%) vs non-responders (30.4%), while all patients (14) with gene AA (17.7%) are responders to standard treatment, while the failure of treatment was more prevalent in CC gene polymorphism (69.2% in non-responder vs 27.8% in responders) which is statistically significant. Our findings demonstrated a strong correlation between patients' responses to H. pylori treatment and polymorphisms in the VDR gene (ApaI and TaqI) (P 0.05).

Conclusion

As far as we are aware, this is the first study to identify a potential link between the FokI and Apal VDR polymorphism and treatment response in H pylori-positive patients. To evaluate the findings, more research with larger number of patients and different population is required.

Vitamin D receptor gene variations and their haplotypic association: Possible impact on gastric cancer risk

Background

Vitamin D receptor (VDR) gene alterations have been associated with the occurrence and prognosis of various types of cancers, but only few studies have focussed on gastric cancer (GC) risk.

Objectives

This case-control study was conceived to evaluate possible association of VDR polymorphisms (Fok1, Taq1, and Cdx2) with GC risk.

Materials and Methods

A total of 293 subjects, including 143 GC patients and 150 controls were included in this study. The genotypes were elucidated by polymerase chain reaction-restriction fragment length polymorphism followed by DNA sequencing.

Results

The frequency of Fok1 genotypes (TC and TT) was found higher in GC cases compared to controls (P ≤ 0.05). In the stratified analysis, we observed a significant association of the (CT + TT) variant with GC risk in males, rural dwellers, smokers, and preobese cases, and those having no family history of Gastrointestinal cancer (P ≤ 0.05). In silico analysis predicted that the Fok1 variant impacts the stability and functional efficiency of the protein. Some exact haplotypes (CCG and CCA) of the VDR gene may act as low penetrance alleles in inclination to GC.

Conclusion

VDR Fok1 polymorphism is significantly associated with GC risk in the Kashmiri population. Specific haplotypes in the VDR gene could act synergistically in the development of GC.

VDR gene polymorphisms are associated with the increased susceptibility to COVID-19 among iranian population: A case-control study

Coronavirus disease 2019 (COVID‐19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), but the pathogenesis is unclear. Host genetic background is one of the main factors influencing the patients' susceptibility to several viral infectious diseases. This study aimed to investigate the association between host genetic polymorphisms of two genes, including vitamin D receptor (VDR) and vitamin D binding protein (DBP), and susceptibility to COVID‐19 in a sample of the Iranian population. This case‐control study enrolled 188 hospitalized COVID‐19 patients as the case group and 218 suspected COVID‐19 patients with mild signs as the control group. The VDR (rs7975232, rs731236 and rs2228570) and DBP (rs7041) gene single nucleotide polymorphisms (SNPs) were genotyped by Polymerase Chain Reaction Restriction – Fragment Length Polymorphism (PCR‐RFLP) method. A significant association between rs2228570 SNP in the VDR gene and the susceptibility of COVID‐19 was found between case and control groups. The CT genotype (Heterozygous) of rs2228570 C > T polymorphism showed significant association with a 3.088 fold increased odds of COVID‐19 (p < .0001; adjusted OR: 3.088; 95% CI: 1.902–5.012). In addition, a significant association between CC genotype of rs2228570 CT polymorphism and increased odds of COVID‐19 in male and female groups (p = .001; adjusted OR: 3.125; 95% CI: 1.630–5.991 and p = .002; adjusted OR: 3.071; 95% CI: 1.485–6.354 respectively) were determined. Our results revealed no significant differences in the frequency of genotype and allele of VDR (rs7975232 and rs731236) and DBP (rs7041) between SARS‐CoV‐2‐infected patients and controls (p > .05). Our results showed that polymorphism of VDR (rs2228570) probably could influence individual susceptibility to COVID‐19. The polymorphisms of VDR (rs7975232 and rs731236) and DBP (rs7041) were not associated with SARS‐CoV‐2 infection susceptibility.

Vitamin D Receptor Genetic Variations May Associate with the Risk of Developing Late Fracture-Related Infection in the Chinese Han Population

Variations in the vitamin D receptor (VDR) gene are related to several inflammatory disorders. However, the potential links between such alternations and the risk of developing late fracture-related infection (FRI) remain unclear. This study investigated associations between genetic variations in the VDR and susceptibility to late FRI in the Chinese Han population. Between January 2016 and December 2019, 336 patients with late FRI and 368 healthy controls were genotyped six VDR genetic variations, including ApaI (rs7975232), BsmI (rs1544410), FokI (rs2228570), TaqI (rs731236), GATA (rs4516035), and Cdx-2 (rs11568820). Significant associations were observed between rs7975232 and FRI susceptibility in the recessive (P = 0.019, OR = 0.530, 95% CI 0.310–0.906) model. Patients with AA genotype had a relatively higher level of serological vitamin D (20.6 vs. 20.3 vs. 17.9 ng/ml) (P = 0.021) than those of AC and CC genotypes. Although no statistical differences were observed, potential correlations may exist between rs1544410 (dominant model: P = 0.079, OR = 0.634), rs2228570 (dominant model: P = 0.055, OR = 0.699), and rs4516035 (dominant model: P = 0.065, OR = 1.768) and the risk of FRI development. In the Chinese cohort, ApaI was associated with a decreased risk of developing FRI, and patients with the AA genotype had a higher vitamin D level. Further studies are required to assess the role of genetic variations in BsmI, FokI, and GATA in the pathogenesis of late FRI.

Association of Vitamin D Receptor Polymorphisms (FokI (Rs2228570), ApaI (Rs7975232), BsmI (Rs1544410), and TaqI (Rs731236)) with Gastric Cancer in a Kurdish Population from West of Iran

Background

The association of 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) and its receptor, vitamin D receptor (VDR), with cancer types have been studied. However, there are controversial findings regarding the association of specific VDR polymorphisms with different kinds of cancers. In the current study, we investigated the association of VDR polymorphisms (Fok1 (rs2228570), ApaI (rs7975232), BsmI (rs1544410), and TaqI (rs731236)) with the risk of gastric cancer in a Kurdish population of Kermanshah in Iran for the first time.

Methods

In this case-control study, the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used in 99 gastric cancer patients and 100 healthy subjects as controls.

Results

The frequencies of f (FokI), b (BsmI), t (TaqI), and a (ApaI) alleles were: 55.6%, 27.3%, 62.1%, and 44.95% in the patient group, respectively and 42%, 29.5%, 54.5%, and 46.0% in the control group, respectively. Analysis of the results indicated that there was a positive association between the frequency of FokI genotypes with gastric cancer risk (p= 0.021). However, no statistically significant association of BsmI, Taq1, and ApaI polymorphisms of VDR was detected in gastric patients when compared with healthy individuals.

Conclusion

VDR-FokI polymorphism could increase the risk of GC development and predispose to the disease by mechanisms.

Association Between Vitamin D Receptor Gene Polymorphisms and Helicobacter Pylori Infection

Background & Aims:

Human genetic polymorphism has been reported in the susceptibility and clinical development of infection. In this regard, this study aimed to investigate the link between Vitamin D Receptor (VDR) gene polymorphism and H. pylori infection.

Materials and Methods:

This cross-sectional study was conducted on 224 adult patients with upper gastrointestinal symptoms who underwent an upper gastrointestinal endoscopy between July 2017 and May 2019 in two major university hospitals. All patients were evaluated for helicobacter pylori infection. Two gastric antral biopsy specimens were taken from each patient. One of those Biopsy specimens was evaluated for histopathology examination and the other one was immersed in a saline solution ready for genomic DNA extraction.

Results:

There were statistically significant differences between different genotypes of VDR rs7975232 polymorphism between H. pylori infected and non-infected groups (CC was higher in H. pylori negative and AC and AA were the most common in H. pylori positive group). There were statistical differences between different genotypes of VDR rs2228570 between H. pylori infected and non-infected groups (TT was higher in H. pylori negative and CT and CC were the most common in H. pylori positive group). Regarding VDR rs 7975232 gene polymorphisms; the (A) allele was significantly higher H. pylori infected, while (C) allele was significantly higher in uninfected patients. Regarding VDR rs 2228570 gene polymorphisms; the (C) allele was significantly higher H. pylori infected, while (T) allele was significantly higher in uninfected patients.

Conclusion:

There is a possible association between the FokI and Apal VDR polymorphism and H. pylori infection.

Positive correlation between vitamin D receptor gene TaqI variant and gastric cancer predisposition in a sample of Iranian population

Gastric cancer is the second cause of cancer-related mortality and the fourth most common cancers worldwide. Owing to the immune modulatory effect of vitamin D in the body, the role of vitamin D receptor gene in vitamin D regulation receives a great deal of research interest. The aim of the current study was to highlight the association between two variants of TaqI and FokI in the vitamin D receptor gene and gastric cancer predisposition in a sample of South Khorasan population. The present investigation consisted of 69 patients affected with gastric cancer and 100 healthy individuals. The genomic DNA was extracted by salting out the protocol from peripheral venous blood. Genotyping of TaqI and FokI variants were performed by PCR-RFLP method. Our findings manifested that TC genotype of TaqI polymorphism was statistically significant between the case and the control groups (p = 0.002). Moreover, the frequency of TC + CC genotypes was statistically significant between the two groups (p = 0.009). Furthermore, we could not find any meaningful association between FokI variant and the participant groups. The present results declared that, in our population, TC genotype of TaqI polymorphism has an association with gastric cancer susceptibility. In addition, more investigation with greater sample sizes is needed to confirm our results.

Effect of 25-hydroxyvitamin D on Helicobacter pylori eradication in patients with type 2 diabetes

BACKGROUND

Various studies have reported a lower Helicobacter pylori eradication rate and a more frequent reinfection rate in type 2 diabetes mellitus (T2DM). Vitamin D has anti-inflammatory and immunoregulatory activity and the role of the vitamin D receptor (VDR) in the antimicrobial activity against H. pylori has been reported. When it comes to the risk factors of H. pylori eradication, the function of vitamin D is not always taken into account. The aim of this study was to assess the role of 25-hydroxyvitamin D in H. pylori eradication in T2DM.

METHODS

In this retrospective study data from 160 patients with T2DM who underwent eradication therapy for H. pylori in Anhui Provincial Hospital between July 2015 and September 2017 were analyzed. According to eradication status, patients were divided into two groups, the successful eradication group (n = 124) and the eradication failure group (n = 36). The following information was obtained from participants' records before eradication treatment: age, sex, body mass index (BMI), duration of T2DM, prescription of medication use, smoking and drinking history. All patients were tested for glycated hemoglobin (HbA1c), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL‑C), triglyceride (TG) and 25-hydroxyvitamin D (25-OHD) at baseline.

RESULTS

The H. pylori was eradicated in 124 (77.5%) patients, while in 36 (22.5%) patients the treatment was unsuccessful. The eradication failure group had a lower mean vitamin D concentration than the group with successful eradication (15.09 ± 7.72 ng/ml vs. 19.87 ± 6.35 ng/ml, p = 0.004). The estimated odds ratio (OR) for eradication failure in individuals with serum vitamin D deficiency (<20 ng/ml) compared to those with sufficient vitamin D levels (>30 ng/ml) were 1.489 (95% confidence interval, CI: 1.046-2.121, P = 0.027), Individuals with long duration of diabetes (≥10 years) had odds of eradication failure of 1.467 (95% CI: 1.017-2.114, P = 0.040) compared to subjects with short duration of diabetes (<10 years).

CONCLUSIONS

Lower 25-OHD was not only associated with H. pylori eradication failure but was also related to dyslipidemia in T2DM patients. Increasing serum 25-OHD to appropriate levels by activated vitamin D use may improve the eradication rate.