HCV F protein amplifies the predictions of IL-28B and CTLA-4 polymorphisms about the susceptibility and outcomes of HCV infection in Southeast China

Cytotoxic T lymphocyte associated antigen-4(CTLA-4) is an inhibitory receptor with great value in the progression of hepatitis C virus (HCV) infection related diseases. To determine the potential associations of IL-28B rs12979860 and CTLA-4 rs231775, rs3087243 and rs5742909 polymorphisms with the generation of HCV F protein, susceptibility and outcomes of HCV infection, a total of 375 healthy controls, 219 HCV spontaneous recovered patients and 600 chronic HCV patients from Southeast China were recruited and genotyped in this study. And the relative mRNA levels of CTLA-4 in T cells were detected. Logistic regression analysis showed that rs231775 A allele was associated with significantly higher rate of spontaneous viral clearance in anti-HCV F antibody negative patients (adjusted OR = 0.512, P = 0.008), but allele A was related to higher mRNA level of CTLA-4 with the generation of HCV F protein. And rs5742909 T allele added up to the risk of HCV infection chronicity significantly in patients with the presence of HCV F protein (adjusted OR = 2.698, P = 0.003). Also, the rs5742909 CC genotype, along with the presence of HCV F protein, indicated a significantly higher CTLA-4 level than that in anti-HCV F antibody negative patients. The AG+AA genotype of rs3087243 significantly increased the susceptibility to HCV infection in subjects over 56 years old (adjusted OR = 1.595, P = 0.011). Genotype–genotype interaction between IL-28B rs12979860 and CTLA-4 rs3087243 was found to be significantly associated with increased susceptibility to HCV infection (adjusted OR = 1.509, P = 0.005). Haplotype analysis in CTLA-4 also showed significant association with the generation of HCV F protein. All these results indicated the importance of IL-28B and CTLA-4 polymorphisms and their associations with HCV F protein in the risk and chronicity of HCV infection in Chinese Han population in Southeast China.     

Toll-like receptor 7 variations are associated with the susceptibility to HCV infection among Chinese females

Toll-like receptors 7 (TLR7) play a crucial role in provoking an immune response in HCV infection. We aimed to investigate whether single nucleotide polymorphisms (SNPs) of TLR7, including rs179009, rs179010 and rs179012, affect the outcomes of HCV infection among the Chinese population. A total of 1767 Chinese Han individuals were enrolled. The distribution of SNP frequencies among three groups with different outcomes of HCV infection was assessed, including healthy controls, cases with spontaneous clearance and cases with viral persistence. Then TLR7 mRNA expression and the production of IFN-α and IL-6 after TLR7 agonist Imiquimod stimulation in vitro were determined. Our results suggested that rs179009 GG genotype was significantly associated with a higher risk of the susceptibility to HCV infection among female subjects (OR = 2.42, 95% CI = 1.24–4.71, P = 0.01). Haplotype GCG was significantly associated with a high risk for HCV susceptibility (OR = 1.50, 95% CI = 1.11–2.03, P = 0.01) as compared with the reference haplotype ACG among females. In the functional research of rs179009, a lower IFN-α level was observed in GG genotype than in AA genotype (P = 0.032). Our data indicate that TLR7 rs179009 GG genotype and haplotype GCG were associated with an increased risk of the susceptibility to HCV infection among Chinese females, which may be due to the impaired IFN-α response.     

Sex-specific association of estrogen receptor 2 polymorphisms with hepatitis C virus infection outcomes in a high-risk Chinese Han population

Hepatitis C virus (HCV) has different clinical and biological characteristics in women versus men, which suggests the potential involvement of estrogen. Estrogen signaling is mediated by the estrogen receptor, and genetic variations in the estrogen receptor gene might affect the pathology of HCV infection. We performed logistic regression analysis to explore the associations between rs1256049, rs4986938 and rs944459 polymorphisms of the estrogen receptor 2 gene (ESR2) and HCV infection outcomes. The variant A allele of rs4986938 was associated with an increased HCV infection susceptibility in the males (additive model: adjusted OR = 1.493, P = 0.010) and a significantly reduced risk of HCV infection in the female subgroup (GA vs. GG: adjusted OR = 0.710, P = 0.012; dominant model: adjusted OR = 0.686, P = 0.004; additive model: adjusted OR = 0.703, P = 0.002). In addition, females carrying the rs4986938 AA genotype appeared to clear HCV spontaneously more readily (adjusted OR = 0.237, P = 0.011), and additive model analyses showed that each additional allele contributed a decreased risk of approximately 34% for HCV chronicity (adjusted OR = 0.659, P = 0.006). Furthermore, a significant multiplicative interaction between the combined rs1256049 and rs4986938 genotypes was found to decrease HCV infection risk (adjusted OR = 0.583, P = 3.000 × 10⁻⁴). The area under the curve, based on the model and including age, gender, HCV genotypes and the three SNPs, was significantly related to the clearance of HCV (P = 0.003). We provide here the first report that rs4986938 in the ESR2 gene played a potential sex-specific role in the etiology of HCV infection in a high-risk Chinese Han population, suggesting that ESR2 is a candidate susceptibility gene for HCV infection and viral clearance.     

Genotyping of vitamin D receptor gene polymorphisms using mismatched amplification mutation assay in neonatal sepsis patients of Odisha,eastern India

Vitamin D has potent antimicrobial and anti-inflammatory properties. Vitamin D deficiency has been shown to be associated with the risk of vulnerability to different infectious diseases, such as neonatal sepsis. Polymorphisms in vitamin D receptor (VDR) gene can influence the expression of vitamin D in individuals. Hence, it is essential to study the vitamin D status and VDR gene polymorphisms for assessing neonatal sepsis risk. In this study, we assessed the serum 25(OH)D, the main circulating form of vitamin D and VDR polymorphism on 120 subjects in a case-control approach, recruiting 60 subjects in each category. We genotyped Fok1, Bsm1, Apa1 and Taq1 gene polymorphisms in VDR by developing a unique mismatch amplification mutation assay (MAMA) and studied their association in both populations. VDR-MAMA primers were designed by addition of dual mismatches (DM) near the 3′ end and were selected based on high ΔCt values in comparison to single mismatch (SM) primers using SYBR-Green RT-PCR, which were eventually used for VDR genotyping. Genotyping was also performed using PCR-RFLP for further confirmation. Serum 25(OH)D ELISA revealed that cases were vitamin D insufficient (Median = 12.16 ng/ml, 95% CI: 3.84–22.22) and controls were vitamin D sufficient (Median = 30.22 ng/ml, 95% CI: 20.08–46.78; p < 0.0001) respectively, which indicated that vitamin D insufficiency was mostly prevalent in cases. We found no evidence of association between genotypes of the Apa1 polymorphism and neonatal sepsis or 25(OH)D serum levels. The distributions of the Fok1, Bsm1, and Taq1 genotypes were not consistent with Hardy-Weinberg equilibrium in the control group. Future studies in larger populations are required to establish whether the VDR polymorphisms can be potentially used as genetic markers for early screening towards predisposition to neonatal sepsis risk. In this study, we describe a simple, inexpensive and rapid screening of VDR gene polymorphisms using VDR MAMA-PCR, which can be used in both clinical and research laboratories.     

Genetic variation in IL28RA is associated with the outcomes of HCV infection in a high-risk Chinese population

Hepatitis C virus (HCV) infection varies in the outcomes depending on both viral and host factors. This study aims to investigate the association of single-nucleotide polymorphisms (SNPs) of IFNAR2, IL10RB, and IL28RA genes with susceptibility to HCV infection and resolution. Genotyping of IFNAR2, IL10RB, and IL28RA gene polymorphisms were performed using TaqMan® method from 552 patients with sero-positive anti-HCV and 421 uninfected controls. The distribution of IFNAR2 and IL10RB genotypes among the control, persistent infection, and spontaneous clearance groups did not differ. However, IL28RA-rs10903035 A allele was over-represented in persistent infection group when compared with uninfected controls and spontaneous clearance group, respectively (OR = 1.54, 95%CI = 1.23–1.92, P = 0.004; OR = 1.42, 95%CI = 1.12–1.81, P = 0.016), and AA genotype had a significant increased risk of persistent infection in different strata except for the females subgroup (P < 0.05). IL28RA-rs11249006 GG genotype showed reduced susceptibility to persistent HCV infection (OR = 0.53, 95%CI = 0.31–0.91, P = 0.044), and the protective effect was significantly different among subgroups stratified by age and likely source of infection (P < 0.05). Besides, AG genotype had a significant negative effect on spontaneous clearance of HCV among young subjects (aged ?40) and patients infected with viral genotype-1 (P < 0.05). Stratified analysis also showed that IL10RB-rs2834167 AG genotype was associated with an increased risk of persistent HCV infection in females, and GG genotype was associated with an increased risk of persistent HCV infection in females and patients with viral genotype non-1 (P < 0.05). Haplotype analysis showed that IL28RA rs10903035-rs11249006 haplotype GG played a protective effect for HCV infection (OR = 0.21, 95%CI = 0.13–0.36, P < 0.001; OR = 0.20, 95%CI = 0.12–0.34, P < 0.001). This study indicates that two SNPs in IL28RA are correlated with susceptibility to HCV infection and spontaneous viral clearance, which implicates a primary role of IL28RA in the outcomes of HCV infection.     

Association of genetic polymorphisms in CD8 + T cell inhibitory genes and susceptibility to and progression of chronic HBV infection

BackgroundPrevious studies have shown that multiple inhibitory genes play an important role in HBV-specific CD8 + T cell exhaustion and dysfunction in the setting of chronic HBV infection. Polymorphic variants of these genes are thought to be predisposing factors for HBV susceptibility, clearance, and disease progression. The aim of this retrospective study was to identify variants affecting chronic HBV infection in a Chinese Han population.MethodsWe chose 28 tgSNPs from HapMap data on 5 key genes. They were genotyped on a total of 858 chronic HBV patients, 429 patients who underwent spontaneous recovery, and 239 healthy controls. We evaluated the correlation between the polymorphisms and HBV susceptibility, spontaneous clearance, and disease progression.ResultsThe association of rs3827537 of BIM genotype TA and allele A was significantly different (P = 0.016, OR = 2.049; P = 0.031, OR = 1.925) between HBV patients and healthy controls. The rs36084323 of PD-1, as well as rs3766377, rs485618, rs4656942 of CD244 showed significant associations with the risk for HBV-related cirrhosis and hepatocellular carcinoma (HCC) (P = 0.009, OR = 0.482; P = 0.009, OR = 4.573; P = 0.015, OR = 0.580; P = 0.028, OR = 2.855). MDR analysis revealed that the four SNPs (rs36084323, rs3766377, rs485618, rs4656942) modulated the predisposition to cirrhosis and HCC in patients with chronic HBV infection (P = 0.006). Using a luciferase reporter assay, we demonstrated that various alleles of rs3766377 had differential effects, and rs3766377 and rs485618 might have interactive effects.ConclusionsThe present study reveals genetic associations among PD-1 and CD244 variants that may be involved in the development of cirrhosis and HCC in patients with chronic HBV infection. The BIM variant was associated with HBV susceptibility.     

rs2243268 and rs2243274 of Interleukin-4 (IL-4) gene are associated with reduced risk for extrapulmonary and severe tuberculosis in Chinese Han children

Interleukin-4 (IL-4) and IL-10, which are produced by Th2 cells, serve as anti-inflammatory cytokines in the immune responses to tuberculosis (TB). In order to investigate the association between susceptibility to TB and single-nucleotide polymorphisms (SNPs) of the IL-4 and IL-10 genes, a case–control study including 346 TB patients and 374 healthy controls was performed in Chinese Han children in North China. Though no significant differences in the allelic and genotypic distributions of SNPs of these two genes were observed between control group and TB group, rs2243268-A and rs2243274-G of the IL-4 gene were associated with reduced risk of developing extrapulmonary tuberculosis (EPTB) (P_rs2243268 = 0.005 and P_rs2243274 = 0.004) and severe TB (P_rs2243268 = 0.003 and P_rs2243274 = 0.003). The haplotype comprising rs2243268-A and rs2243274-G was found to be a resistance factor against EPTB and severe TB. In addition, after stimulation with inactivated H37Rv, blood samples of the rs2243268 AA + AC carriers showed significantly reduced IL-10 production (P = 0.045) compared to the CC carriers. In conclusion, rs2243268-A and rs2243274-G of the IL-4 gene were found to confer resistance to EPTB and severe TB in Chinese Han children.     

Protective effects of HLA-DPA1/DPB1 variants against Hepatitis B virus infection in an Indonesian population

Human leukocyte antigen (HLA) DPA1/DPB1 variants have been reported to influence Hepatitis B virus (HBV) infection. HLA-DPA1/DPB1 plays a pivotal role in antigen presentation to CD4⁺ helper T cells and influences the outcome of HBV infection. To investigate the influence of HLA-DP variants on the outcome of HBV infection in an Indonesian population where it has the third-highest prevalence of HBV infection worldwide, we performed a case–control study of 686 participants, including patients with HBV-related advanced or nonadvanced liver disease, patients with spontaneously resolved HBV, and healthy controls. Single-nucleotide polymorphisms in HLA-DPA1 (rs3077) and HLA-DPB1 (rs3135021, rs9277535, and rs228388) were genotyped using real-time TaqMan® genotyping assays. Because rs2281388 deviated from Hardy–Weinberg equilibrium, it was excluded from subsequent analyses. The results of logistic regression analyses showed that the HLA-DPB1 rs9277535 variants were associated with a reduced risk of persistent HBV infection (odds ratio [OR] 0.70, 95% confidence interval [95% CI] 0.52–0.96, P = 0.026, additive genetic model; OR 0.60, 95% CI 0.38–0.96, P = 0.033, dominant genetic model). The HLA-DPA1 rs3077 variant was associated with a protective effect increasing the spontaneously resolved HBV infection (OR 0.64, 95% CI 0.41–0.98, P = 0.039, dominant genetic model). By contrast, the HLA-DPB1 rs3135021 variant was not associated with the outcome of HBV infection, including susceptibility, spontaneously resolved, or disease progression. Combinations of haplotype markers were also associated with HBV susceptibility (CA for rs3077–rs9277535, OR 0.57, 95% CI 0.36–0.92, P = 0.021; GA for rs3135021–rs9277535, OR 0.56, 95% CI 0.36–0.86, P = 0.0087). In conclusion, these findings confirm that HLA-DPA1/DPB1 variants were associated with the outcomes of HBV infection in an Indonesian population.     

Vitamin D3 and 25-hydroxyvitamin D3 in raw and cooked pork cuts

The contents of vitamin D₃ and its metabolically active metabolite 25-hydroxyvitamin D₃ (25OHD₃) were examined by HPLC in different parts of four common raw pork cuts (loin boneless, leg inside, thin belly, neck) and in cooked meat (loin boneless). In whole raw pork cuts, varying in fat content from 2.2 to 26.5 g/100 g, concentrations of vitamin D₃ from 0.05 to 0.21 μg/100 g were measured. Pork cuts also contained significant amounts of 25OHD₃, from 0.07 to 0.14 μg/100 g. Further, the study demonstrated that most of the vitamin D₃ and 25OHD₃ is located in the fatty tissues, and that rind, despite its limited fat content, has a high concentration of vitamin D₃ and 25OHD₃. Cooking increased vitamin D₃ and 25OHD₃ calculated per 100 g of tissue in all parts and in the whole cut (in whole cuts in raw and cooked meat, respectively: vitamin D₃: 0.15 (0.08–0.24) μg/100 g and 0.18 (0.11–0.28) μg/100 g; P=0.33; 25OHD₃: 0.09 (0.06–0.18) μg/100 g and 0.13 (0.10–0.18) μg/100 g; P=0.02); however, correcting for differences in dry matter content, ameliorated all significant differences. 25OHD₃ has a higher (from 1.5 to 5 times) biological activity than vitamin D₃. Meat 25OHD₃ contributes significantly to vitamin D activity. Food databases should include concentrations of both vitamin D and 25OHD.     

Genetic variants at 18q11.2 and 8q24 identified by genome-wide association studies were not associated with pulmonary tuberculosis risk in Chinese population

ObjectiveGenome-wide association study (GWAS) recently identified several susceptibility loci in ASAP1 gene on chromosome 8q24 for tuberculosis (TB) in a Russian population, but no relevant studies have been performed to validate these findings. In addition, previous GWAS in Ghana and Gambia found that the variant rs4331426 at 18q11.2 was a susceptibility locus for TB. However, the follow-up studies reported conflicting results. Herein, we investigated the contribution of genetic variants at 8q24 and 18q11.2 to TB in Chinese population.MethodsWe genotyped four genetic variants at 8q24 (rs10956514 and rs11774633) and 18q11.2 (rs4331426 and rs6507226) in a case–control study with 355 newly bacteriologically confirmed pulmonary TB cases and 395 healthy controls using TaqMan allelic discrimination assay. Subsequently, we conducted a meta-analysis including 4 reported studies in Chinese populations and our case–control study with a total of 3118 cases and 3226 controls to further evaluate the relationship between rs4331426 at 18q11.2 and TB risk.ResultsWe did not find significant association between genetic variants at 8q24 and risk of TB (rs10956514: OR = 0.89, 95%CI: 0.72–1.09, P = 0.253; rs11774633: OR = 0.86, 95%CI: 0.69–1.08, P = 0.206). We did not observe significant association for genetic variants at 18q11.2 (rs4331426: OR = 0.62, 95%CI: 0.34–1.14, P = 0.122; and rs6507226: OR = 0.98, 95%CI: 0.80–1.20, P = 0.853). Moreover, the pooled results from the Meta-analysis further supported that rs4331426 at 18q11.2 was not associated with TB risk in Chinese population (OR = 0.90, 95% CI: 0.63–1.29).ConclusionsOur findings indicate that TB risk-associated loci at 8q24 and 18q11.2 identified by GWAS from the other populations may not contribute to TB susceptibility in Chinese population.     

Association of human leukocyte antigen DP/DQ gene polymorphisms with chronic hepatitis B in Chinese Han and Uygur populations

Several genome-wide association studies (GWAS) have shown that human leukocyte antigen (HLA) DP/DQ gene polymorphisms are associated with susceptibility to chronic hepatitis B virus (HBV) infection. We clarified the roles of the HLA-DP/DQ gene in HBV infection in different nationalities. Three single nucleotide polymorphisms (SNPs) in HLA-DP (rs9277471, rs9277535 and rs9277542) and the SNP rs9272346 in HLA-DQ were studied. In total, 779 patients were recruited to this study, including 400 Chinese Han and 399 Uygurs. The rs9277535 variant genotypes were directly associated with HBV persistence compared to healthy controls in an additive model of the Chinese Han population (odds ratio [OR] = 1.88, 95% confidence interval [CI] = 1.03–3.41, P = 0.040), and in a recessive model of the Chinese female population (OR = 2.02, 95% CI = 1.26–3.24, P = 0.003). In addition, rs9277471 and rs9277542 variant genotypes significantly decreased the risk of HBV infection compared to healthy controls in an additive model of the Chinese Han population (OR = 0.53, 95% CI = 0.29–0.98, P = 0.042; OR = 0.53, 95% CI = 0.29–0.97, P = 0.039) and in a dominant model of the Chinese female population (OR = 0.50, 95% CI = 0.31–0.80, P = 0.004; OR = 0.49, 95% CI = 0.31–0.79, P = 0.003). The GG genotype of rs9277346 was associated with HBV infection in the Chinese Han population (additive model: OR = 0.38, 95%CI = 017–0.82, P = 0.014; recessive model: OR = 0.41, 95% CI = 0.19–0.86, P = 0.019) and in males (additive model: OR = 0.31, 95% CI = 0.14–0.65, P = 0.002; dominant model: OR = 0.65, 95% CI = 0.43–0.97, P = 0.034; recessive model: OR = 0.36, 95% CI = 0.18–0.73, P = 0.005). In addition, allele G of rs9277346 was marginally related to a reduction in risk for HBV infection in the Uygur population. Our study suggests that HLA-DP/DQ polymorphisms can affect susceptibility and resistance to HBV infection in Chinese populations, and are possibly linked to race and sex.     

The -94Ins/DelATTG polymorphism in NFκB1 promoter modulates chronic hepatitis C and liver disease progression

Infection with Hepatitis C Virus (HCV) is one of the most important risk factor of hepatocellular carcinoma (HCC). HCV is suspected to induce HCC primarily through chronic inflammation and promotion of cirrhosis, a well-known pre-neoplastic condition. The NF-κB pathway is a key regulator of immune and inflammatory processes and plays a pivotal role in oncogenesis. Genetic variations affecting the pathway may alter NF-κB activity in response to HCV infection and contribute to liver tumorigenesis. The present study aims to evaluate the association between -94Ins/DelATTG (rs28362491) polymorphism in NF-κB1 gene promoter region and 2758G > A (rs696) single nucleotide polymorphism in the 3ʹUTR region of NFκBIA and the outcomes of HCV infection.In this case–control study, 559 subjects (343 patients with HCV infection including 237 mild chronic hepatitis patients and 106 patients with Advanced Liver Disease (AdLD), 78 individuals who naturally cleared HCV and 138 healthy subjects) were genotyped for the NFκB1 and NFκBIA SNPs using PCR-RFLP. Logistic regression was used to assess the association between polymorphisms and the outcome and progression of the infection.Variation at rs696 was not associated with HCV resolution or progression (P > 0.05). By contrast, the Ins/Ins genotype was associated with a 4-fold increase of AdLD risk when compared to mild chronic hepatitis C (OR = 4.69; 95% CI, 2.15–10.19; P = 0.0001) and the risk was more pronounced when compared to healthy controls (OR = 5.02; 95% CI, 2.30–10.98; P = 0.00005). Furthermore, carriage of Ins allele at rs28362491 was significantly associated with higher viral loads (P = 0.003).Our results suggest that variation in NFκB1 gene promoter modulates the progression of chronic hepatitis C toward advanced liver disease.     

Association between TLR3 rs3775291 and resistance to HIV among highly exposed Caucasian intravenous drug users

BackgroundTLR3 recognizes dsRNA and triggers immune responses against RNA and DNA viruses. A polymorphism in TLR3, rs3775291 (Leu412Phe), has been associated with the increased susceptibility to enteroviral myocarditis, protection against tick-borne encephalitis virus and HIV-1 infection. We investigated Caucasian intravenous drug users (IDUs) and blood donors in order to evaluate the associations between TLR3 genotypes and susceptibility to HIV infection.Materials and methodsA total of 345 Caucasian IDUs were recruited, 50% of them were HIV positive, 89% HCV and 77% HBV positive. Based on their history of needle sharing, 20 of the HIV negative IDUs were classified as highly exposed HIV seronegatives (HESNs), 68 as non-HESNs and 85 as unexposed. The control group consisting of 497 blood donors tested negative for all three viruses. TLR3 rs3775291 were determined by using TaqMan Allelic Discrimination Assay.ResultsThe TLR3 rs3775291 T allele frequency was similar among the HIV negative and HIV positive IDUs and blood donors – 36%, 31% and 34%, respectively. The frequency of persons possessing at least one TLR3 rs3775291 T allele was significantly higher in HESNs compared with blood donors and HIV positive IDUs (80% vs. 55%; p = 0.037 and 80% vs. 53%; p = 0.031, respectively). In the univariate analysis, persons who possessed at least one T allele had reduced odds of being HIV seropositive (OR = 0.29, 95% CI = 0.09–0.90). This association remained significant (OR = 0.25, 95% CI = 0.07–0.87) after the adjustment for other co-variates (HCV, HBV serostatus and duration of intravenous drug use).ConclusionsThe TLR3 rs3775291 T allele has a protective effect against HIV infection among HESNs IDUs.     

Rs1914663 of SFTPA 1 gene is associated with pediatric tuberculosis in Han Chinese population

Surfactant protein A (SP-A), a part of the innate immune system of the lung, performs a vital role in the host defense against Mycobacterium tuberculosis (MTB) infection. In order to investigate the relationship between SFTPA polymorphism variations and Tuberculosis (TB) in a Chinese pediatric group, we conducted a case–control study using single-nucleotide polymorphism (SNP) analysis. Significant difference of the allelic distribution of rs1914663 in SFTPA gene was observed between TB group and control group and, T allele of rs1914663 was associated with increased risk for TB (control vs. TB, OR: 1.42, 95% CI: 1.10–1.81, P = 0.005). In addition, the TC + TT genotype of rs1914663 was higher in PTB and non-severe TB than that in controls. The haplotype comprising rs17881720-A and rs17879335-G was a resistance factor while the haplotype comprising rs1914663-T and rs1059225-G was found to be a susceptibility factor to TB. Using a case–control study, we identified a genetic polymorphism in the SFTPA that regulates host susceptibility to pediatric TB in the Han Chinese population.     

Analysis of TLR4 (Asp299Gly and Thr399Ile) gene polymorphisms and mRNA level in patients with dengue infection: A case-control study

BackgroundDengue is a systemic viral infection that spreads to humans by the bite of infected Aedes mosquitoes. The secreted NS1 protein of dengue virus activates macrophages and human PBMCs via TLR4 and induce the release of pro-inflammatory cytokines which is responsible for the pathogenesis of disease. Mutations in TLR4 gene have been associated with the increased susceptibility to many viral, bacterial and parasitic diseases.ObjectiveTo study the impact of TLR4 Asp299Gly (rs4986790) and Thr399Ile (rs4986791) gene polymorphisms with susceptibility to dengue infection.MethodsA total of 120 dengue infected (57; DHF/DSS and 63; DF) and 200 healthy controls were included in the study. TLR4 Asp299Gly and Thr399Ile gene polymorphisms was studied by PCR-RFLP. Expression of TLR4 mRNA was evaluated by rRT-PCR.ResultsIndividuals with heterozygous genotype for TLR4 Asp299Gly and Thr399Ile polymorphisms had increased susceptibility to dengue infection (OR-1.70, 95% CI = 1.01–2.86 P = 0.042 and OR-2.17, 95% CI = 1.10–4.28, P = 0.024, respectively). The frequency of Gly and Ile alleles were higher in dengue patients as compared to controls (OR-1.67, 95% CI = 1.05–2.64, P = 0.029 and OR-2.20, 95% CI = 1.19–4.07, P = 0.011, respectively). IIe/Gly haplotype was associated with the risk of the disease when compared with controls (OR = 3.15, 95% CI = 1.09–9.09, P = 0.035). The mRNA expression was higher in DF when compared with DHF/DSS and controls (P = 0.040 and 0.009, respectively).ConclusionA higher expression of TLR4 mRNA was associated with DF. The TLR4 Asp299Gly and Thr399Ile gene polymorphisms were associated with the susceptibility of dengue infection probably by altering the immune response.     

Influence of HLA-G polymorphisms in human immunodeficiency virus infection and hepatitis C virus co-infection in Brazilian and Italian individuals

ObjectiveThis study aimed to investigate the role of Human Leukocyte Antigen (HLA)-G in the susceptibility to HIV-1 infection through the analysis of the HLA-G 3′ untranslated region (UTR) polymorphisms 14 bp insertion/deletion (rs66554220) and +3142C>G (rs1063320).DesignWe analyzed 582 HIV-1 infected patients and 626 uninfected individuals from Brazil and Italy in a case-control study.MethodsHLA-G polymorphisms were genotyped using PCR, PCR-RFLP assays or direct sequencing. All analyses were stratified by ethnicity. Genotypic, allelic and diplotypic frequencies were compared between HIV-1 infected subjects and controls using Chi-square or Fischer exact tests. Also, haplotypic frequencies were estimated using MLocus software.ResultsAfrican-derived HIV-infected individuals presented a higher frequency of the 14 bp insertion allele as compared to non-infected individuals (0.468 versus 0.373, respectively; p_Bonf = 0.010). A higher frequency of the 14 bp insertion +3142G (insG) haplotype (0.456 versus 0.346, p < 0.001) and the insG/insG diplotype (OR = 1.88, 95%CI = 1.08–3.23, p = 0.021) was observed among African-derived patients as compared to uninfected controls. Also, we observed a higher frequency of the ins/ins genotype among African-derived HIV patients co-infected with HCV (OR = 2.78, 95%CI = 1.20–6.49, p = 0.008).ConclusionsOur data point out to an increased frequency of alleles and genotypes associated with low HLA-G expression among African-derived patients, suggesting a potential role for HLA-G in the susceptibility to HIV-1 infection and HCV co-infection in those individuals.     

Interferon-γ (IFNG) microsatellite repeat and single nucleotide polymorphism haplotypes of IFN-α receptor (IFNAR1) associated with enhanced malaria susceptibility in Indian populations

Pro-inflammatory cytokines IFNγ and IFNα function through their cellular receptors IFNγR1 and IFNαR1, respectively to mediate immune processes during malaria infection. A total of 21 SNPs, 2 ins/del polymorphisms and a microsatellite repeat, selected on the basis of their reported association with infectious diseases including malaria in world populations, were analysed for association with Plasmodium falciparum malaria susceptibility in a case-control study with adult patients and ethnically-matched controls drawn from a disease meso- to hyperendemic and a nonendemic region of India. Among the five IFNG SNPs tested, an intron 3 and a 3′UTR SNP associated with disease in the endemic region. In addition, large (CA)_n repeats of IFNG intron 1 associated with protection from severe malaria in the endemic region (severe vs. control, odds ratio = 0.21, 95% CI = 0.08–0.52, P = 1.3 × 10⁻⁴). The TA11CAG haplotype (rs2069705 T/C, rs2430561 A/T, rs3138557 (CA)_n, rs2069718 T/C, rs2069727 A/G, rs2069728 G/A) carrying a short CA₁₁ repeat also exhibited very strong association with severe malaria, particularly in the endemic region (severe vs. control, OR = 14.56, 95% CI = 3.39–85.81, P = 3 × 10⁻⁵). One SNP each from the IFNA8 and IFNA17 of IFNA gene cluster had a protective effect in the non-endemic region but not in the endemic region. A promoter and an intron 2 SNP of IFNAR1 were risk factors for disease and the IFNAR1 haplotype GCCAGG (rs2843710 C/G, rs2850015 C/T, +6993 C/T, rs2243594 A/G, rs1012335 G/C, rs2257167 G/C) carrying both the risk alleles strikingly associated with disease manifestation in the endemic region (severe vs. control, OR = 27.14, 95% CI = 3.12–1254, P = 2 × 10⁻⁵; non-severe vs. control, OR = 61.87, 95% CI = 10.08–2521, P = 1 × 10⁻⁸). The data indicates dissimilar contribution of cytokine and cytokine receptor variants to disease in populations residing in areas of differential malaria endemicity.     

SFRP1 variations influence susceptibility and immune response to Mycobacterium tuberculosis in a Chinese Han population

ObjectivesSFRP1 acts as a well-established inhibitory regulator of the Wnt signaling pathway, whose polymorphisms have been demonstrated to be associated with the risk of inflammation, infection as well as cancer. We verified the hypothesis that single nucleotide polymorphisms (SNPs) within SFRP1 gene are associated with susceptibility and clinical characteristics of tuberculosis disease in a Chinese Han population.MethodsSix candidate SNPs were genotyped using MassARRAY method in a case–control design (260 tuberculosis patients and 252 healthy controls). A comprehensive analysis of single locus including the genotypic, allelic frequencies and the genetic models, haplotypic construction as well as gene–gene interaction was conducted to investigate the relationships between SNPs and TB. Significant SNPs were further interrogated in relation to TB clinical features and host inflammatory status.ResultsGenotype frequencies of rs4736958 and rs7832767 within SFRP1 gene were significantly different (p = 0.011, p = 0.008, respectively) between tuberculosis group and control group. Subjects carrying C allele for rs4736958 showed a decreased tuberculosis risk (OR = 0.66, 95% CI = 0.51–0.87, p = 0.003), whereas individuals carrying rs7832767 T allele had a significant increased risk in tuberculosis susceptibility (OR = 1.32, 95% CI = 1.01–1.74, p = 0.046). Genetic model analysis revealed that dominant, co-dominant and recessive models of rs4736958 were associated with decreased susceptibility to tuberculosis (p all < 0.05), while the recessive and co-dominant models of rs7832767 were related to significantly increased risk for tuberculosis (p all < 0.05). There was a reduced tuberculosis risk in association with the haplotype CC (representing rs3242 and rs4736958) of SFRP1 (OR = 0.73, 95% CI = 0.56–0.96, p = 0.026). Further stratification analysis indicated that TB patients with genotype CT for rs4736958 were associated with higher CRP concentrations, and heterozygous patients (CT genotype) of rs7832767 trended towards greater ESR levels.ConclusionSNPs rs4736958 and rs7832767 of SFRP1 gene were significantly associated with tuberculosis susceptibility and might influence the expression levels of inflammatory markers of tuberculosis patients in a Chinese Han population.     

Genetic polymorphisms of the IFNλ genes are associated with biochemical features in Han Chinese with HCV infection from Yunnan Province,China

Hepatitis C virus (HCV) is the pathogenic factor for hepatitis C disease, which could lead to chronic or serious hepatic diseases. Previous studies have identified that the IL28B gene polymorphisms were associated with therapeutic effect and viral clearness of HCV patients. We aimed to test whether genetic polymorphisms of three IFNλ genes (IL28A, IL28B and IL29) are associated with HCV infection in Han Chinese. We collected whole blood of 261 HCV infectious patients without any therapy and 265 matched normal controls from Yunnan Province. Among these subjects, 28.4% (74/261) of HCV patients and 26.8% (71/265) of controls were male. Ten SNPs (rs8099917, rs10853728, rs11883177, rs12980602, rs4803224, rs11671087, rs11665818, rs8108008, rs7248931, and rs30461), which covered the whole region of the IL28A, IL28B, and IL29 genes, were genotyped. Our results showed that there was no association between genotypes and alleles of the IFNλ gene polymorphisms and HCV infection. One haplotype (TGCTGTGGAT), which was consisted of ten SNPs, showed a significantly higher frequency in HCV patients (11/522 = 2.1%) than in controls (1/530 = 0.2%) (P = 0.003). We performed association analyses for biochemical features and genotype of each SNP, and found that HCV patients with certain genotypes of some SNPs had a higher level of the ALT/AST ratio and total blood bilirubin (TBIL) compared to healthy controls. Our results suggested the IFNλ gene polymorphisms might be associated with clinical features of HCV patients from Yunnan Province, China.