Association of vitamin D receptor gene polymorphisms with response to peginterferon plus ribavirin in Asian patients with chronic hepatitis C

Single-nucleotide polymorphisms in genes associated with the vitamin D pathway related to clinical and therapeutic outcomes of American tegumentary leishmaniasis

Background

The vitamin D pathway contributes to the microbicidal activity of macrophages against Leishmania infection. In addition to induction of this pathway, interferon-gamma (IFNγ), interleukin (IL)-15, and IL32γ are part of a network of pro-inflammatory cytokines. The aim of this study was to evaluate single-nucleotide polymorphisms (SNPs) in the components of the vitamin D pathway and associated cytokine genes that could be related to resistance or susceptibility to American tegumentary leishmaniasis (ATL).

Methods

The expressions of IFNG, IL15, IL32, CYP27B1, VDR, and other pro-inflammatory cytokines TNF, IL6, and IL17 genes were evaluated using real-time polymerase chain reaction (qPCR) in lesions of patients with localized cutaneous leishmaniasis (LCL) or mucosal leishmaniasis (ML). SNP genotypes/alleles (in IL15, IL32, CYP27B1, and VDR) were evaluated by TaqMan PCR assays using DNA from the blood of patients and healthy individuals. Serum vitamin D levels were determined by chemiluminescence.

Results

Vitamin D pathway-associated genes were expressed in cutaneous as well as mucosal lesions. IFNG, IL6, and IL17 were more highly expressed in ML than in LCL. In contrast, IL32γ/CYP27B1/VDR mRNAs were mainly correlated in LCL, and IL32γ in ML makes strong connections with all cytokines. The SNP IL32 rs1555001 was less frequent in patients with ML. In addition, some SNPs appear to influence the VDR and CYP27B1 (IL15 rs10519613 and IL15 rs3775597) and IL6 (VDR rs7975232) expressions in LCL and the IL17 expression in ML (IL15 rs3775597). Gene expression was also correlated with clinical parameters, such as number of lesions (CYP27B1 mRNA) and treatment failure (VDR mRNA). In addition, one SNP was associated with treatment failure in ML (VDR rs7975232).

Conclusions

Our findings suggested that some SNPs in the vitamin D pathway-associated genes can be related to resistance and therapeutic outcomes of ATL. They are promising candidates that need to be further evaluated to understand their biological effects in the control or immunopathogenesis of ATL.

Treatment outcome and germline predictive factors of ropeginterferon alpha-2b in myeloproliferative neoplasm patients

BACKGROUND

Studies have shown that some single nucleotide polymorphisms (SNPs) could serve as excellent markers in foretelling the treatment outcome of interferon (IFN) in myeloproliferative neoplasms (MPN). However, most work originated from western countries, and data from different ethnic populations have been lacking.

METHODS

To gain insights, targeted sequencing was performed to detect myeloid-associated mutations and SNPs in eight loci across three genes (IFNL4, IFN-γ, and inosine triphosphate pyrophosphatase [ITPA]) to explore their predictive roles in our cohort of 21 ropeginterferon alpha-2b (ROPEG)-treated MPN patients, among whom real-time quantitative PCR was also performed periodically to monitor the JAK2V617F allele burden in 19 JAK2V617F-mutated cases.

RESULTS

ELN response criteria were adopted to designate patients as good responders if they achieved complete hematological responses (CHR) within 1 year (CHR1) or attained major molecular responses (MMR), which occurred in 70% and 45% of the patients, respectively. IFNL4 and IFN-γ gene SNPs were infrequent in our population and were thus excluded from further analysis. Two ITPA SNPs rs6051702 A>C and rs1127354 C>A were associated with an inferior CHR1 rate and MMR rate, respectively. The former seemed to be linked to grade 2 or worse hepatotoxicity as well, although the comparison was of borderline significance only (50%, vs. 6.7% in those with common haplotype, p = 0.053). Twelve patients harbored 19 additional somatic mutations in 12 genes, but the trajectory of these mutations varied considerably and was not predictive of any response.

CONCLUSIONS

Overall, this study provided valuable information on the ethnics- and genetics-based algorithm in the treatment of MPN.

Controversial Effects of Vitamin D and Related Genes on Viral Infections, Pathogenesis, and Treatment Outcomes

Vitamin D (VD) plays an essential role in mineral homeostasis and bone remodeling. A number of different VD-related genes (VDRG) are required for the metabolic activation of VD and the subsequent induction of its target genes. They include a set of genes that encode for VD-binding protein, metabolic enzymes, and the VD receptor. In addition to its well-characterized skeletal function, the immunoregulatory activities of VD and the related polymorphisms of VDRG have been reported and linked to its therapeutic and preventive actions for the control of several viral diseases. However, in regards to their roles in the progression of viral diseases, inconsistent and, in some cases, contradictory results also exist. To resolve this discrepancy, I conducted an extensive literature search by using relevant keywords on the PubMed website. Based on the volume of hit papers related to a certain viral infection, I summarized and compared the effects of VD and VDRG polymorphism on the infection, pathogenesis, and treatment outcomes of clinically important viral diseases. They include viral hepatitis, respiratory viral infections, acquired immunodeficiency syndrome (AIDS), and other viral diseases, which are caused by herpesviruses, dengue virus, rotavirus, and human papillomavirus. This review will provide the most current information on the nutritional and clinical utilization of VD and VDRG in the management of the key viral diseases. This information should be valuable not only to nutritionists but also to clinicians who wish to provide evidence-based recommendations on the use of VD to virally infected patients.

Genetic associations of vitamin D receptor polymorphisms with advanced liver fibrosis and response to pegylated interferon-based therapy in chronic hepatitis C

Vitamin D receptor (VDR) modulates host immune responses to infections such as hepatitis C virus (HCV) infection, including interferon signaling. This study aimed to investigate the associations of VDR polymorphisms with advanced liver fibrosis and response to pegylated interferon (PEG-IFN)-based therapy in patients with chronic HCV infection. In total, 554 Thai patients with chronic HCV infection treated with a PEG-IFN-based regimen were enrolled. Six single-nucleotide polymorphisms (SNPs) were genotyped: the IL28B C > T (rs12979860) SNP and five VDR SNPs, comprising FokI T > C (rs2228570), BsmI C > T (rs1544410), Tru9I G > A (rs757343), ApaI C > A (rs7975232), and TaqI A > G (rs731236). In total, 334 patients (60.3%) achieved sustained virological response (SVR), and 255 patients (46%) were infected with HCV genotype 1. The bAt (CCA) haplotype, consisting of the BsmI rs1544410 C, ApaI rs7975232 C, and TaqI rs731236 A alleles, was associated with poor response (in terms of lack of an SVR) to PEG-IFN-based therapy. The IL28B rs12979860 CT/TT genotypes (OR = 3.44, 95% CI [2.12-5.58], p < 0.001), bAt haplotype (OR = 2.02, 95% CI [1.04-3.91], p = 0.03), pre-treatment serum HCV RNA (logIU/mL; OR = 1.73, 95% CI [1.31-2.28], p < 0.001), advanced liver fibrosis (OR = 1.68, 95% CI [1.10-2.58], p = 0.02), and HCV genotype 1 (OR = 1.59, 95% CI [1.07-2.37], p = 0.02) independently predicted poor response. Patients with the bAt haplotype were more likely to have poor response compared to patients with other haplotypes (41.4% vs 21.9%, p = 0.03). The FokI rs2228570 TT/TC genotypes (OR = 1.63, 95% CI [1.06-2.51], p = 0.03) and age ≥55 years (OR = 2.25; 95% CI [1.54-3.32], p < 0.001) were independently associated with advanced liver fibrosis, assessed based on FIB-4 score >3.25. VDR polymorphisms were not associated with pre-treatment serum HCV RNA. In Thai patients with chronic HCV infection, the bAt haplotype is associated with poor response to PEG-IFN-based therapy, and the FokI rs2228570 TT/TC genotypes are risk factors for advanced liver fibrosis.

Role of VDR, GC, and CYP2R1 Polymorphisms in the Development of Hepatocellular Carcinoma in Hepatitis C Virus-Infected Patients

Aims: This study was designed to determine if vitamin D receptor (VDR), carrier globulin/binding protein (GC), and cytochrome P-450 family 2, subfamily R, polypeptide 1 (CYP2R1) gene polymorphisms are risk factors in the development of hepatocellular carcinoma (HCC) in hepatitis C virus (HCV)-infected patients from Northeast India. Materials and Methods: A total of 351 HCV-infected patients were enrolled of which 167 were diagnosed with chronic hepatitis C (CHC), 124 with liver cirrhosis (LC), and 60 with HCC together with 102 age- and sex-matched healthy controls. VDR (BsmI, ApaI, and TaqI), GC (rs4588, rs7051), and CYP2R1 (rs10741657) gene polymorphisms were genotyped for all subjects. Statistical data were analyzed using SPSS ver. 22.0. Results: The frequency of the ApaI CC genotype, ApaI C allele, and bAt haplotype of the VDR gene was significantly higher in HCC and LC patients than controls. After adjusting for other covariates (age, gender, platelet count, AST, ALT, serum albumin, and viral load) logistic regression analysis showed that the ApaI CC genotype and bAt haplotype were independent predictors of HCC development. No significant associations was found for the GC and CYP2R1 polymorphisms examined with the occurrence of HCC. Conclusions: The presence of the VDR ApaI CC genotype and bAt haplotype appear to be important indicators in the development of HCC among HCV-infected patients. Larger studies are needed to further clarify and establish this potential causal relationship.

VDR rs7975232/ApaI genetic variation predicts sustained HBsAg loss in HBeAg-positive chronic hepatitis B patients treated with pegylated interferon

AIM

To evaluate the predictive value of vitamin D and its metabolic pathway gene polymorphisms in response to pegylated interferon (Peg-IFN) in hepatitis B early antigen (HBeAg)-positive chronic hepatitis B (CHB) patients.

METHODS

One hundred and nineteen HBeAg-positive CHB patients who received Peg-IFN monotherapy for 48 weeks and then were followed-up for another 48 weeks were prospectively enrolled; baseline 25-hydroxy vitamin D (25-(OH)D) and hepatitis B virus serologic marker levels were detected, nine critical single nucleotide polymorphisms within vitamin D metabolism were genotyped.

RESULTS

Forty-five (37.8%), 44 (37.0%), 35 (29.4%), and 11 (9.2%) of the patients achieved virological response (VR), HBeAg loss, combined response (CR), and hepatitis B surface antigen (HBsAg) level < 200 IU/mL at the end of treatment (EOT; week 48), respectively; 42 (35.3%) and six (5.0%) people achieved HBeAg and HBsAg loss at the end of follow-up (EOF; week 96). Baseline HBeAg level was independent predictor of VR (odds ratio [OR], 0.470; 95% confidence interval [CI], 0.294-0.751; P = 0.002), HBeAg loss (OR, 0.395; 95% CI, 0.243-0.643; P < 0.001), CR (OR, 0.392; 95% CI, 0.215-0.714; P = 0.002) at EOT and HBeAg loss at EOF (OR, 0.334; 95% CI, 0.203-0.559; P < 0.001); baseline HBsAg level itself was independent predictor of both HBsAg < 200 IU/mL at EOT (OR, 0.257; 95% CI, 0.103-0.642; P = 0.004) and HBsAg loss at EOF (OR, 0.232; 95% CI, 0.077-0.702; P = 0.010). Age was also independent predictors of HBsAg loss at EOF (OR, 0.775; 95% CI, 0.634-0.948; P = 0.013). Concerning genetic variation of VDR rs7975232/ ApaI, A allele was the genetic independent predictor of VR at EOT (OR, 1.824; 95% CI, 1.024-3.248; P = 0.041) and HBsAg loss at EOF (OR, 3.566; 95% CI, 1.057-12.029; P = 0.040).

CONCLUSIONS

Genetic variation of VDR rs7975232/ ApaI is a pretreatment predictor of sustained HBsAg loss in HBeAg-positive CHB patients with Peg-IFN monotherapy.

Vitamin D deficiency in hepatitis C virus infection: what is old? what is new?

In the past few years, a growing body of clinical evidence has highlighted the risk of vitamin D deficiency in patients with chronic hepatitis C and that vitamin D levels are associated with the course of hepatitis C virus (HCV) infection, adverse effects, and treatment response to peginterferon/ribavirin. Recently, studies have found that vitamin D status is related to drug resistance and increased risk of infection in patients with liver cirrhosis. Vitamin D-related gene polymorphisms have been found to explain the interactions between vitamin D deficiency and HCV infection, offering a new perspective toward understanding the current problems such as the development of insulin resistance and racial differences in sustained virological response. Studies have been conducted to determine whether vitamin D supplementation as an adjuvant yields a better result compared with traditional HCV treatment. Here, we provide a brief review of the past and present knowledge of vitamin D in HCV infection.

Impact of vitamin D receptor and binding protein gene polymorphisms in clinical and laboratory data of HCV patients: Cross sectional study

Potential relationship of vitamin D, vitamin D receptor (VDR), and vitamin D binding protein (DBP) have been suggested in the pathophysiology of hepatitis C virus (HCV) infection. The aim of this observational study is to determine vitamin D levels, and VDR and DBP genetic polymorphism according demographic and laboratory data in chronic HCV patients (CHC).A total of 148 CHC patients gave serum samples for testing 25-hydroxyvitamin D (25 (OH)D) level by immunochemiluminometric assay (<20 ng/mL defined as deficient) and donated blood samples to allelic discrimination analysis using TaqMan assays. Analyzed single nucleotide polymorphisms (SNPs) were: VDR-rs7975232 (ApaI) C>A, rs731236 A>G (TaqI), rs1544410 C>T (BsmI), rs10735810 T>C (FokI) and carrier globulin/binding protein (GC)-rs4588 and rs7041 and the haplotype bAt [CCA]. Hepatic fibrosis was assessed using Fib-4 and Forns index.Eighty-two (54.40%) patients demonstrated deficiency of vitamin D and this was associated to AST (P = .019 [CI: 1.003-1.034]), total cholesterol (P = .038 [CI: 1.004-1.164]), fibrosis grade (P < .001 [CI: 0.000-0.844]), and FokI (P = .028) allele T presence. Association was found between VDR polymorphism and fibrosis (BsmI andTaqI), triglycerides (TaqI), and HDL (FokI). DBP polymorphism was associated to HCV genotype (GC rs7041), previous HCV treatment, and GGT (GC rs4588).In conclusion, low frequency of vitamin D deficiency was found, but VDR polymorphisms were frequently associated to fibrosis grade suggesting that they could be used as disease evaluation markers to understand the mechanisms underlying the virus-host interaction.

Vitamin D-related gene polymorphism predict treatment response to pegylated interferon-based therapy in Thai chronic hepatitis C patients

BACKGROUND

Patients with chronic hepatitis C (HCV) infection have high prevalence of vitamin D deficiency. Genome-wide association study data has showed that several genetic variants within vitamin D cascade affect vitamin D function. This study aimed to determine whether genetic polymorphisms of genes in the vitamin D pathway are associated with treatment responses to pegylated interferon (PEG-IFN)-based therapy in patients with chronic HCV infection.

METHODS

The study included 623 Thai patients from 2 university hospitals diagnosed with chronic HCV infection who were treated with a PEG-IFN and ribavirin. Patients were genotyped for functional variants on vitamin D synthetic pathway including GC (rs4588, rs7041, rs22020, rs2282679), CYP2R1 (rs2060793, rs12794714), CYP27B1 (rs10877012), and DHCR7 (rs12785878). Pre-treatment predictors of sustained virologic response (SVR) at 24 weeks following discontinuation of therapy were identified using a logistic regression analysis.

RESULTS

SVR was achieved by 60.5% of patients (52.9% with HCV genotype 1; 66.7% with HCV non-genotype 1). In 44.6% of HCV genotype 1-infected patients, only the variant rs12785878 in the DHCR7 locus was significantly associated with an SVR. HCV genotype 1 patients who had DHCR7 rs12785878 GT/TT had a higher rate of SVR than those with the GG allele (59.7% vs. 43.4%, P = 0.03), but in HCV non-genotype 1-infected patients, the SVR rate did not differ between the two groups (63.3% and 59.1% for GT/TT and GG allele, P = 0.54). By multivariate analysis, liver fibrosis stage 0-1 (OR = 5.00; 95% CI, 2.02-12.37; P < 0.001), and DHCR7 rs12785878 GT/TT allele (OR = 2.69; 95% CI, 1.03-7.05; P = 0.04) were independent pre-treatment predictors of SVR following PEG-IFN-based therapy in HCV genotype 1 patients. Baseline HCV RNA < 400,000 IU/ml (OR = 1.96; 95% CI, 1.13-3.39; P = 0.02) was the only independent predictor of SVR in HCV non-genotype 1 patients. The polymorphisms of GC, CYP2R1 and CYP27B1 were not associated with treatment outcome even in genotype 1 or non-genotype 1 HCV infection.

CONCLUSION

The DHCR7 polymorphism may be a pre-treatment predictive marker for response to PEG-IFN-based therapy in chronic HCV genotype 1 infection.

Vitamin D in liver disease: Current evidence and potential directions

Consistent with its multifaceted nature, growing evidence links vitamin D with hepatic disease. In this review, we summarise the roles of vitamin D in different liver pathologies and explore the clinical utility of vitamin D-based treatments in hepatology. We find that the small number of clinical trials coupled with the profound heterogeneity of study protocols limits the strength of evidence needed to ascribe definite clinical value to the hormone in liver disease. Nevertheless, the experimental data is promising and further bench and bedside studies will likely define a clearer role in hepatic therapeutics.