The Expression Levels of TREX1 and IFN-α Are Associated with Immune Reconstitution in HIV-1-Infected Individuals.

TREX1 acts in the initial prevention of an autoimmune response, but it may contribute to the permissiveness of retrovirus infections. This study investigated the association between the levels of TREX1 gene expression with the polymorphisms TREX1 rs3135941 (T/C) and TREX1 rs3135945 (G/A), and the presence of antinuclear antibodies (ANA) in antiretroviral therapy (ART)-naïve individuals and after 1 year of treatment. Blood samples from 119 individuals with HIV-1 were subjected to genotyping of polymorphisms and quantification of TREX1 gene expression and HIV-1 viral load by qPCR. The concentration of IFN-α and the number of CD4+/CD8+ T lymphocytes were determined by ELISA and flow cytometry, respectively; ANA was investigated by immunofluorescence. A control group of 167 seronegative individuals was used for the comparison of genotypic frequencies. The frequency of the polymorphisms were not associated with HIV infection or with variations in the expression of TREX1 and IFN-α (p > 0.05). ART-naïve individuals exhibited higher TREX1 expression and lower IFN-α expression. After 1 year of ART, TREX1 levels were reduced, while IFN-α and CD4+ T lymphocytes were elevated (p < 0.05). Some individuals on ART presented ANA. These results suggest that ART-mediated restoration of immune competence is associated with a reduction in TREX1 expression, which may induce the development of ANA, regardless of the polymorphism investigated.

Severe COVID-19 and long COVID are associated with high expression of STING, cGAS and IFN-α.

The cGAS-STING pathway appears to contribute to dysregulated inflammation during coronavirus disease 2019 (COVID-19); however, inflammatory factors related to long COVID are still being investigated. In the present study, we evaluated the association of cGAS and STING gene expression levels and plasma IFN-α, TNF-α and IL-6 levels with COVID-19 severity in acute infection and long COVID, based on analysis of blood samples from 148 individuals, 87 with acute COVID-19 and 61 in the post-COVID-19 period. Quantification of gene expression was performed by real-time PCR, and cytokine levels were quantified by ELISA and flow cytometry. In acute COVID-19, cGAS, STING, IFN-α, TNF-α, and IL-6 levels were higher in patients with severe disease than in those with nonsevere manifestations (p < 0.05). Long COVID was associated with elevated cGAS, STING and IFN-α levels (p < 0.05). Activation of the cGAS-STING pathway may contribute to an intense systemic inflammatory state in severe COVID-19 and, after infection resolution, induce an autoinflammatory disease in some tissues, resulting in long COVID.

TREX1 531C/T Polymorphism and Autoantibodies Associated with the Immune Status of HIV-1-Infected Individuals.

Autoimmune diseases can develop during HIV-1 infection, mainly related to the individual's immune competence. The study investigated the association of the TREX1 531C/T polymorphism and antinuclear antibodies (ANA) in HIV-1 infection and the time of antiretroviral therapy (ART) used. Cross-sectional and longitudinal assessments were carried out in 150 individuals, divided into three groups: ART-naïve, 5 years and 10 years on ART; ART-naïve individuals were evaluated for 2 years after initiation of treatment. The individuals' blood samples were submitted to indirect immunofluorescence tests, real-time PCR and flow cytometry. The TREX1 531C/T polymorphism was associated with higher levels of TCD4+ lymphocytes and IFN-α in individuals with HIV-1. Individuals on ART had a higher frequency of ANA, higher levels of T CD4+ lymphocytes, a higher ratio of T CD4+/CD8+ lymphocytes and higher levels of IFN-α than therapy-naïve individuals (p < 0.05). The TREX1 531C/T polymorphism was associated with better maintenance of the immune status of individuals with HIV-1 and ANA with immune restoration in individuals on ART, indicating the need to identify individuals at risk of developing an autoimmune disease.

Polymorphisms in the MBL2 gene are associated with the plasma levels of MBL and the cytokines IL-6 and TNF-α in severe COVID-19.

Introduction: Mannose-binding lectin (MBL) promotes opsonization, favoring phagocytosis and activation of the complement system in response to different microorganisms, and may influence the synthesis of inflammatory cytokines. This study investigated the association of MBL2 gene polymorphisms with the plasma levels of MBL and inflammatory cytokines in COVID-19. Methods: Blood samples from 385 individuals (208 with acute COVID-19 and 117 post-COVID-19) were subjected to real-time PCR genotyping. Plasma measurements of MBL and cytokines were performed by enzyme-linked immunosorbent assay and flow cytometry, respectively. Results: The frequencies of the polymorphic MBL2 genotype (OO) and allele (O) were higher in patients with severe COVID-19 (p< 0.05). The polymorphic genotypes (AO and OO) were associated with lower MBL levels (p< 0.05). IL-6 and TNF-α were higher in patients with low MBL and severe COVID-19 (p< 0.05). No association of polymorphisms, MBL levels, or cytokine levels with long COVID was observed. Discussion: The results suggest that, besides MBL2 polymorphisms promoting a reduction in MBL levels and therefore in its function, they may also contribute to the development of a more intense inflammatory process responsible for the severity of COVID-19.

Low levels of TNFA gene expression seem to favor the development of pulmonary tuberculosis in a population from the Brazilian Amazon.

TNF-α is a Th1 cytokine profile active in the control of Mycobacterium tuberculosis infection, IL-10 is associated with persistence of bacterial infection. The aim of the study was to investigate the association of TNFA -308G/A and IL10 -819C/T polymorphisms and TNFA and IL10 gene expression levels with pulmonary and extrapulmonary tuberculosis (n = 200) and control (n = 200). The individuals were submitted to genotyping and quantification of gene expression performed by real-time quantitative polymerase chain reaction (qPCR). No association was observed between the frequencies of polymorphisms evaluated and pulmonary tuberculosis. The frequency of polymorphic genotypes for TNFA -308G/A were associated with the extrapulmonary tuberculosis (p = 0.0445). The levels of TNFA expression were lower in the pulmonary tuberculosis group than in the control (p = 0.0009). There was a positive correlation between the levels of TNFA and IL10 in patients with pulmonary tuberculosis (r = 0.560; p = 0.0103). Reduced levels of TNFA expression may promote the formation of an anti-inflammatory microenvironment, favoring the persistence of the bacillus in the host, contributing to the establishment of pulmonary tuberculosis.

Epidemiological and Cytokine Profile of Patients with Pulmonary and Extrapulmonary Tuberculosis in a Population of the Brazilian Amazon.

Several factors are associated with the development of different clinical forms of tuberculosis (TB). The present study evaluated epidemiological variables and cytokine levels in samples from 89 patients with TB (75 with pulmonary TB and 14 with extrapulmonary TB) and 45 controls. Cytokines were measured by flow cytometry (Human Th1/Th2/Th17 Cytometric Bead Array kit). The TB group had a higher frequency of individuals who were 39 years of age or older, married, with primary education or illiterate and had a lower family income (p < 0.05). All individuals with extrapulmonary TB reported that they were not working, and the main reasons were related to disease symptoms or treatment. The levels of IFN-γ (OR = 4.06) and IL-4 (OR = 2.62) were more likely to be elevated in the TB group (p = 0.05), and IFN-γ levels were lower in patients with extrapulmonary TB compared to those with pulmonary TB (OR = 0.11; p = 0.0050). The ROC curve was applied to investigate the diagnostic accuracy of IFN-γ levels between the different clinical forms of tuberculosis, resulting in high AUC (0.8661; p < 0.0001), sensitivity (93.85%) and specificity median (65.90%), suggesting that IFN-γ levels are useful to differentiate pulmonary TB from extrapulmonary TB. The dysregulation of pro- and anti-inflammatory cytokine levels represent a risk for the development of TB and contribute to the pathogenesis of the disease, especially variation in IFN-γ levels, which may determine protection or risk for extrapulmonary TB.

The IL6-174G/C Polymorphism Associated with High Levels of IL-6 Contributes to HCV Infection, but Is Not Related to HBV Infection, in the Amazon Region of Brazil.

The dysregulation of cytokine production can lead to an inefficient immune response, promoting viral persistence that induces the progression of chronic viral hepatitis. The study investigated the association of the IL6-174G/C polymorphism with changes in cytokine levels and its influence on the persistence and progression of chronic hepatitis caused by HBV and HCV in 72 patients with chronic hepatitis B (HBV), 100 patients with hepatitis C (HCV), and a control group of 300 individuals. The genotyping of the IL6-174G/C polymorphism was performed by real-time PCR, and cytokine levels were measured by enzyme-linked immunosorbent assay (ELISA). HCV patients with the wild-type genotype (GG) had a higher viral load (p = 0.0230). The plasma levels of IL-6 were higher among patients infected with HBV and HCV than among the control group (p < 0.0001). Patients with HCV were associated with increased inflammatory activity (A2−A3; p < 0.0001). In hepatitis C, carriers of the GG genotype had higher levels of IL-6 (p = 0.0286), which were associated with A2−A3 inflammatory activity (p = 0.0097). Patients with A2−A3 inflammatory activity and GG genotype had higher levels of IL-6 than those with the GC/CC genotype (p = 0.0127). In conclusion, the wild-type genotype for the IL6-174G/C polymorphism was associated with high levels of IL-6 and HCV viral load and inflammatory activity, suggesting that this genotype may be a contributing factor to virus-induced chronic infection.

Plasma Levels of sFas-sFasL and FASL Gene Expression Are Associated with Tuberculosis.

Apoptosis of macrophages infected by Mycobacterium tuberculosis via Fas-FasL is an important immune mechanism against infection. This study investigated the association of tuberculosis (TB) with the presence of the polymorphisms FAS -670A/G and FASL -124A/G, the levels of sFas and sFasL, and the gene expression of FASL and cytokines. Samples of 200 individuals diagnosed with TB and 200 healthy controls were evaluated. Real-time PCR (genotyping and gene expression) and ELISA (dosages of sFas, sFasL, IFN-γ, and IL-10) tests were performed. There was no association of FAS -670A/G and FASL -124A/G polymorphisms with TB. The TB group exhibited high plasma levels of sFas and reduced plasma levels of sFasL (p < 0.05). The correlation analysis between these markers revealed a positive correlation between the levels of sFas and sFasL, sFasL and FASL expression, and between sFas and FASL expression (p < 0.05). In the TB group, there was a positive correlation between FASL expression and IFN-γ levels and higher levels of IL-10 compared to IFN-γ (p < 0.05). High levels of sFas and reduced levels of sFasL and FASL expression may contribute to the inhibition of apoptosis in infected cells and represent a possible bacterial resistance resource to maintain the infection.

The Genetic Profile and Serum Level of IL-8 Are Associated with Chronic Hepatitis B and C Virus Infection.

The present study evaluated the IL8-251 A/T polymorphism in samples from 74 patients with chronic hepatitis B (HBV), 100 patients with chronic hepatitis C (HCV), and 300 healthy donors (CG). The correlations of this polymorphism with plasma IL-8 and disease stage were calculated. Polymorphisms were identified by real-time PCR. IL-8 was measured by enzyme-linked immunosorbent assay. The IL8-251 A/T genotype was not associated with susceptibility to infection by HBV or HCV. The wild-type allele (A) was associated with higher levels of inflammation (p = 0.0464) and fibrosis scores (p = 0.0016) in the HBV group, representing an increased risk for increased inflammatory activity (OR = 1.84; p = 0.0464) and for high fibrosis scores (OR = 2.63; p = 0.0016). Viral load was higher in HBV patients with polymorphic genotypes (TA and TT) at the IL8-251 A/T polymorphism than in those with the wild-type genotype (p = 0.0272 and p = 0.0464, respectively). Plasma IL-8 was higher among patients infected with HBV or HCV than in the control group (p = 0.0445 and p = 0.0001, respectively). The polymorphic genotype was associated with lower IL-8 than the wild-type genotype in the HBV group (p = 0.0239) and the HCV group (p = 0.0372). The wild-type genotype for IL8-251 A/T and high IL-8 were associated with a worse prognosis for infections; therefore, they may contribute to viral persistence and the development of more severe forms of chronic viral liver diseases.

Intrahepatic TLR3 and IFNL3 Expressions Are Associated with Stages of Fibrosis in Chronic Hepatitis C.

An inefficient immune response against the hepatitis C virus (HCV), combined with viral evasion mechanisms, is responsible for the chronicity of infection. The need to evaluate the innate mechanisms of the immune response, such as TLR3 and IFN-λ3, and their relationship with the virus-host interaction is important for understanding the pathogenesis of chronic hepatitis C. The present study aimed to investigate the gene expressions of TRL3 and IFNL3 in liver tissue, seeking to evaluate whether these could be potential biomarkers of HCV infection. A total of 23 liver biopsy samples were collected from patients with chronic HCV, and 8 biopsies were collected from healthy control patients. RNA extraction, reverse transcription and qPCR were performed to quantify the relative gene expressions of TLR3 and IFNL3. Data on the viral load; AST, ALT, GGT and AFP levels; and the viral genotype were collected from the patients' medical records. The intrahepatic expression of TLR3 (p = 0.0326) was higher in chronic HCV carriers than in the control group, and the expression of IFNL3 (p = 0.0037) was lower in chronic HCV carriers than in the healthy control group. The expression levels of TLR3 (p = 0.0030) and IFNL3 (p = 0.0036) were higher in the early stages of fibrosis and of necroinflammatory activity in the liver; in contrast, TLR3 and IFNL3 expressions were lower in the more advanced stages of fibrosis and inflammation. There was no correlation between the gene expression and the serum viral load. Regarding the initial METAVIR scale scores, liver transaminase levels were lower in patients with advanced fibrosis when correlated with TLR3 and IFNL3 gene expressions. The results suggest that in the early stages of the development of hepatic fibrosis, TLR3 and IFN-λ3 play important roles in the antiviral response and in the modulation of the tolerogenic liver environment because there is a decrease in the intrahepatic expressions of TLR3 and IFNL3 in the advanced stages of fibrosis, probably due to viral evasion mechanisms.

Intrahepatic interleukin 10 expression modulates fibrinogenesis during chronic HCV infection.

INTRODUCTION: Liver fibrosis is a result of continuous damage to the liver combined with accumulation of the extracellular matrix and is characteristic of most chronic liver diseases such as hepatitis C virus (HCV) infection. METHODS: This study evaluated interleukin 10 (IL10) expression in the liver and plasma of 45 HCV patients and its association with the pathogenesis and progression of liver fibrosis. The expression of transforming growth factor beta (TGFB1) was also assessed. Patients were divided into three groups according to the METAVIR classification (F0-F1, F2 and F3-F4); there was also a control group (n = 8). RESULTS: In the control group, high intrahepatic IL10 mRNA expression showed a positive association with F0-F1 fibrosis, no inflammation, low concentrations of liver enzymes and a high viral load; conversely, low intrahepatic IL10 mRNA expression showed a negative association with fibrosis progression. Intrahepatic TGFB1 mRNA expression was greater in the HCV group than in the control group, and regarding different disease phases, its expression increased as fibrosis evolved to more severe forms. CONCLUSION: Intrahepatic IL10 mRNA expression decreases with persistent fibrosis, probably due to the production of TGF-ß1, a potent antimitotic and fibrogenic cytokine. IL10 restricts and decreases the immune response and limits the fibrogenic response; however, a decrease in IL10 favors persistent inflammatory infiltrate, resulting in severe fibrosis.

The SAMHD1 rs6029941 (A/G) Polymorphism Seems to Influence the HTLV-1 Proviral Load and IFN-Alpha Levels.

SAMHD1, a host dNTPase, acts as a retroviral restriction factor by degrading the pool of nucleotides available for the initial reverse transcription of retroviruses, including HTLV-1. Polymorphisms in the SAMDH1 gene may alter the enzymatic expression and influence the course of infection by the virus. The present study investigated the effect of polymorphisms on HTLV-1 infection susceptibility and on progression to disease in 108 individuals infected by HTLV-1 (47 symptomatic and 61 asymptomatic) and 100 individuals in a control group. SAMHD1 rs6029941 (G/A) genotyping and HTLV-1 proviral load measurements were performed using real-time PCR and plasma IFN-α was measured by ELISA. Polymorphism frequency was not associated with HTLV-1 infection susceptibility or with the presence of symptoms. The proviral load was significantly higher in symptomatic individuals with the G allele (p = 0.0143), which presented lower levels of IFN-α (p = 0.0383). SAMHD1 polymorphism is associated with increased proviral load and reduced levels of IFN-α in symptomatic patients, and may be a factor that contributes to the appearance of disease symptoms.

TREX1 531C>T Polymorphism is Associated with High Proviral Load Levels in HTLV-1-Infected Persons.

Human T-lymphotropic virus type 1 (HTLV-1) deregulates the immune system and cell cycle, resulting in loss of immune tolerance and disease, including HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Three prime repair exonuclease 1 (TREX1) maintains innate immune tolerance of the host and host-cell permissiveness to retroviral infections. TREX1 polymorphisms may influence the course of infection and autoimmune manifestations. The influence of TREX1 531C/T polymorphism was investigated in HTLV-1 infection and development of symptoms among 151 persons infected with HTLV-1 (32 HAM/TSP, 19 rheumatologic manifestations, two dermatitis, five more than one diagnosis, two probable HAM/TSP, and 91 asymptomatic individuals) and 100 uninfected persons in the control group. Polymorphism genotyping and proviral load quantification were performed by real-time polymerase chain reaction (PCR) and antinuclear antibodies (ANAs) were screened by an indirect immunofluorescence assay. No statistically significant difference was found in polymorphism genotype and allele frequencies between the infected and control groups. HAM/TSP patients showed higher frequency of TT genotype than asymptomatic persons (p = 0.0339). Proviral load was significantly higher among individuals with CT/TT genotypes and CC genotype carriers had lower proviral load and higher levels of proinflammatory cytokines. ANAs were present only in the HAM/TSP group. TREX1 531C>T polymorphism seems to be associated with TREX-1 regulation and HTLV-1 infection.

Association of serum levels of C-reactive protein with CRP-717 T/C polymorphism and viremia in HCV and HBV carriers.

INTRODUCTION: The present study investigated the association of the rs2794521 polymorphism in the CRP gene in individuals with chronic hepatitis B and C, correlating it with markers of hepatic inflammation, fibrosis scores, viral load, and plasma protein levels. METHODS: The study analyzed 185 blood samples obtained from patients with hepatitis B (n=74) and hepatitis C (n=111) and 300 samples from healthy donors. Genotyping was performed by real-time polymerase chain reaction, and protein levels were quantified using the automated immunoturbidimetric method. RESULTS: The TT genotype was the most frequent in all studied groups and was associated with higher plasma levels of the protein but not with the progression of liver disease. Low levels of C-reactive protein were associated with increased viremia and scores indicative of severe fibrosis and cirrhosis. CONCLUSIONS: The present results demonstrated a close relationship between the ability of the virus to replicate and cause liver damage and low serum concentrations of C-reactive protein. Future research may determine if these results can be interpreted as a possible form of escape for the virus by decreasing its action as an opsonin and decreasing phagocytosis, which are functions of C-reactive protein in the immune response.

Association of serum levels of C-reactive protein with CRP-717 T/C polymorphism and viremia in HCV and HBV carriers

Abstract INTRODUCTION: The present study investigated the association of the rs2794521 polymorphism in the CRP gene in individuals with chronic hepatitis B and C, correlating it with markers of hepatic inflammation, fibrosis scores, viral load, and plasma protein levels. METHODS: The study analyzed 185 blood samples obtained from patients with hepatitis B (n=74) and hepatitis C (n=111) and 300 samples from healthy donors. Genotyping was performed by real-time polymerase chain reaction, and protein levels were quantified using the automated immunoturbidimetric method. RESULTS: The TT genotype was the most frequent in all studied groups and was associated with higher plasma levels of the protein but not with the progression of liver disease. Low levels of C-reactive protein were associated with increased viremia and scores indicative of severe fibrosis and cirrhosis. CONCLUSIONS: The present results demonstrated a close relationship between the ability of the virus to replicate and cause liver damage and low serum concentrations of C-reactive protein. Future research may determine if these results can be interpreted as a possible form of escape for the virus by decreasing its action as an opsonin and decreasing phagocytosis, which are functions of C-reactive protein in the immune response.

The -3279C>A and -924A>G polymorphisms in the FOXP3 Gene Are Associated With Viral Load and Liver Enzyme Levels in Patients With Chronic Viral Liver Diseases.

The transcription factor FOXP3 is an essential marker of the development and activation of regulatory T cells (Tregs), which are cells specialized in the regulation and normal tolerance of the immune response. In the context of chronic viral liver diseases, Tregs participate in the maintenance of infections by promoting histopathological control and favor the immune escape of viral agents by suppressing the antiviral response. Single nucleotide polymorphisms (SNPs) may influence the function of FOXP3 in a number of pathological conditions. The present study sought to evaluate the influence of SNPs in the FOXP3 gene promoter region in patients with chronic viral liver diseases. Three SNPs (-3279C>A, -2383C>T, and -924A>G) were analyzed in groups of patients with chronic hepatitis C (CHC), active chronic hepatitis B (CHB-A), inactive chronic hepatitis B (CHB-I), and a healthy control group (CG) using real-time PCR. The frequencies of the polymorphic variants were compared between groups and correlated with liver histopathological characteristics and enzyme levels [i.e., alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT)] obtained via biopsy and from the clinical records of the participating patients, respectively. For the -2338C>T SNP, no significant differences were found in the frequencies of variants between groups or in the histological findings. Significant associations between the polymorphisms and the CHB-I group were not established. The -3279C>A SNP was associated with altered viral loads (log10) and GGT levels in CHC patients with advanced stages of inflammatory activity and liver fibrosis. The -924A>G SNP was associated with altered viral loads (log10) and liver enzyme levels among CHB-A patients with milder inflammation and fibrosis. However, the frequencies of the -3279C>A and -924A>G polymorphisms were not directly associated with the histopathological profiles of the analyzed patients. These polymorphic variants may influence hepatic function in patients with chronic viral liver diseases but are not directly associated with the establishment of the degree of inflammatory activity and liver fibrosis.

HBV Viral Load and Liver Enzyme Levels May Be Associated with the Wild MBL2 AA Genotype.

The present study investigated the frequencies of rs1800450 (MBL ⁎B, G>A), rs1800451 (MBL ⁎C, G>A), and rs5030737 (MBL ⁎D, C>T) polymorphisms in exon 1 of the MBL2 gene among patients with chronic viral hepatitis. Blood samples from patients infected with hepatitis B virus (HBV; n = 65), hepatitis C virus (HCV; n = 92), and a noninfected control group (n = 300) were investigated. The presence of polymorphisms was detected using a real-time polymerase chain reaction to correlate with liver disease pathogenesis and fibrosis staging according to the Metavir classification. The genotypic and allelic frequencies showed no significant differences between the groups, but patients with active HBV and the wild AA genotype presented a positive correlation between increased transaminase and HBV DNA levels and the presence of mild to moderate fibrosis. Patients with HCV and the wild AA genotype presented mild inflammation and higher HCV RNA levels, although the same association was not observed for the fibrosis scores. The results suggest that the mutations in exon 1 of the MBL2 gene do not contribute directly to the clinical and laboratory features of HCV and HBV infections, but further studies should be performed to confirm whether the wild AA genotype has indirect effect on disease progression.

Intrahepatic mRNA Expression of FAS, FASL, and FOXP3 Genes Is Associated with the Pathophysiology of Chronic HCV Infection.

UNLABELLED: This study aimed to evaluate the relative mRNA expression of Fas receptor (FAS), Fas ligand (FASL), and forkhead box protein 3 (FOXP3) in liver biopsy specimens obtained from patients with viral and non-viral chronic hepatitis and correlate their expression with the fibrosis stage. A total of 51 liver biopsy specimens obtained from HBV (n = 6), HCV (n = 28), and non-viral hepatic disease (NVHD) (n = 9) patients and from individuals with normal liver histology (n = 8) (control-CT) were analyzed. Quantifications of the target genes were assessed using qPCR, and liver biopsies according to the METAVIR classification. The mRNA expression levels of FAS and FASL were lower in the CT group compared to the groups of patients. The increase in the mRNA expression of FAS and FASL was correlated with higher levels of inflammation and disease progression, followed by a decline in tissues with cirrhosis, and it was also associated with increased levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Higher mRNA expression of FOXP3 was observed in the HCV and NVHD groups, with the peak observed among patients with cirrhosis. The increased FOXP3 mRNA expression was positively correlated with increased FAS and FASL mRNA expression and the AST and ALT levels in all patients. CONCLUSIONS: These results suggest that regardless of the cause, the course of chronic liver disease may be modulated by the analyzed genes and correlated with an increase in regulatory T cells during the liver damage followed by hepatocyte destruction by Fas/FasL system and subsequent non specific lymphocytic infiltrate accumulation.

Lack of Association between Polymorphisms of the TLR4 Gene and Infection with the Hepatitis B and C Viruses.

Toll-like receptor 4 (TLR4) plays a crucial role in the early recognition of pathogenic microorganisms and provides an ideal model to investigate the consequences of genetic variation and susceptibility to diseases. The present study investigated the occurrence of the single nucleotide polymorphisms (SNPs) rs4986790 (A>G) and rs4986791 (C>T) in the TLR4 gene in chronic carriers of the hepatitis B (HBV) and C (HCV) viruses. A total of 420 blood samples were collected (HBV, 49; HCV, 72; and controls, 299) at the liver disease outpatient clinic of Hospital da Fundação Santa Casa de Misericórdia do Pará (FSCMPA). Genomic DNA extracted from leukocytes was subjected to real-time polymerase chain reaction (qPCR) analysis to identify the genetic profile of the participants. No significant differences were found in the allele and genotype frequencies between the infected participants and controls. No significant associations were found between the investigated polymorphisms and inflammatory activity, fibrosis, and the presence of cirrhosis; the same results were obtained in the haplotype analysis. The results showed a lack of association between the rs4986790 and rs4986791 SNPs and susceptibility to infection with HBV and HCV, as well as clinical and laboratory information of the patients.

Toll-like receptor 3 gene polymorphisms are not associated with the risk of hepatitis B and hepatitis C virus infection.

INTRODUCTION: The present study investigated the prevalence of two single-nucleotide polymorphisms (SNPs) in the Toll-like receptor 3 (TLR3) gene in patients infected with hepatitis B virus (HBV) and hepatitis C virus (HCV). METHODS: Samples collected from HCV (n = 74) and HBV (n = 35) carriers were subjected to quantitative real-time PCR (qPCR) to detect the presence of the SNPs rs5743305 and rs3775291 in TLR3 and to measure the following biomarkers: alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), and prothrombin time (PT). A healthy control group was investigated and consisted of 299 HCV- and HBV-seronegative individuals. RESULTS: No significant differences in allele, genotype and haplotype frequencies were observed between the investigated groups, and no association was observed between the polymorphisms and histopathological results. Nevertheless, genotypes TA/AA (rs5743305) and GG (rs3775291) appear to be associated with higher levels of ALT (p<0.01), AST (p<0.05) and PT (p<0.05). In addition, genotypes TT (rs5743305; p<0.05) and GG (rs3775291; p<0.05) were associated with higher GGT levels. CONCLUSIONS: This genetic analysis revealed the absence of an association between the polymorphisms investigated and susceptibility to HBV and HCV infection; however, these polymorphisms might be associated with a greater degree of biliary damage during the course of HCV infection.