Influence of HLA haplotypes on the clinical courses of individuals infected with hepatitis C virus

Understanding Immune Responses to Viruses-Do Underlying Th1/Th2 Cell Biases Predict Outcome?

Emerging and re-emerging viral diseases have increased in number and geographical extent during the last decades. Examples include the current COVID-19 pandemic and the recent epidemics of the Chikungunya, Ebola, and Zika viruses. Immune responses to viruses have been well-characterised within the innate and adaptive immunity pathways with the outcome following viral infection predominantly attributed to properties of the virus and circumstances of the infection. Perhaps the belief that the immune system is often considered as a reactive component of host defence, springing into action when a threat is detected, has contributed to a poorer understanding of the inherent differences in an individual's immune system in the absence of any pathology. In this review, we focus on how these host factors (age, ethnicity, underlying pathologies) may skew the T helper cell response, thereby influencing the outcome following viral infection but also whether we can use these inherent biases to predict patients at risk of a deviant response and apply strategies to avoid or overcome them.

A large-scale investigation into the role of classical HLA loci in multiple types of severe infections, with a focus on overlaps with autoimmune and mental disorders

Background

Infections are a major disease burden worldwide. While they are caused by external pathogens, host genetics also plays a part in susceptibility to infections. Past studies have reported diverse associations between human leukocyte antigen (HLA) alleles and infections, but many were limited by small sample sizes and/or focused on only one infection.

Methods

We performed an immunogenetic association study examining 13 categories of severe infection (bacterial, viral, central nervous system, gastrointestinal, genital, hepatitis, otitis, pregnancy-related, respiratory, sepsis, skin infection, urological and other infections), as well as a phenotype for having any infection, and seven classical HLA loci (HLA-A, B, C, DPB1, DQA1, DQB1 and DRB1). Additionally, we examined associations between infections and specific alleles highlighted in our previous studies of psychiatric disorders and autoimmune disease, as these conditions are known to be linked to infections.

Results

Associations between HLA loci and infections were generally not strong. Highlighted associations included associations between DQB1*0302 and DQB1*0604 and viral infections (P = 0.002835 and P = 0.014332, respectively), DQB1*0503 and sepsis (P = 0.006053), and DQA1*0301 with “other” infections (a category which includes infections not included in our main categories e.g. protozoan infections) (P = 0.000369). Some HLA alleles implicated in autoimmune diseases showed association with susceptibility to infections, but the latter associations were generally weaker, or with opposite trends (in the case of HLA-C alleles, but not with alleles of HLA class II genes). HLA alleles associated with psychiatric disorders did not show association with susceptibility to infections.

Conclusions

Our results suggest that classical HLA alleles do not play a large role in the etiology of severe infections. The discordant association trends with autoimmune disease for some alleles could contribute to mechanistic theories of disease etiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02888-1.

Association of HLA-B22 serotype with SARS-CoV-2 susceptibility in Hong Kong Chinese patients

The coronavirus disease 2019 (COVID‐19) is a highly infectious disease caused by SARS‐CoV‐2. Since its first report in December 2019, COVID‐19 has evolved into a global pandemic causing massive healthcare and socioeconomic challenges. HLA system is critical in mediating anti‐viral immunity and recent studies have suggested preferential involvement of HLA‐B in COVID‐19 susceptibility. Here, by investigating the HLA‐B genotypes in 190 unrelated Chinese patients with confirmed COVID‐19, we identified a significant positive association between the B22 serotype and SARS‐CoV‐2 infection (p = 0.002, Bonferroni‐corrected p = 0.032). Notably, the B22 serotype has been consistently linked to susceptibility to other viral infections. These data not only shed new insights into SARS‐CoV‐2 pathogenesis and vaccine development but also guide better infection prevention/control.

HLA Class II-DRB1 Alleles with Hepatitis C Virus Infection Outcome in Egypt: A Multicentre Family-based Study

INTRODUCTION AND AIM

Hepatitis C virus (HCV) infection is a global medical problem. HLA -DRB1 alleles have an important role in immune response against HCV. The aim of this study is to clarify the contribution of HLA -DRB1 alleles in HCV susceptibility in a multicentre family-based study.

MATERIAL AND METHODS

A total of 162 Egyptian families were recruited in this study with a total of 951 individuals (255 with chronic hepatitis C (CHC), 588 persons in the control group(-ve household contact to HCV) and 108 persons who spontaneously cleared the virus (SVC). All subjects were genotyped for HLA -DRB1 alleles by SSP-PCR and sequence based typing (SBT) methods.

RESULTS

The carriage of alleles 3:01:01 and 13:01:01 were highly significant in CHC when compared to that of control and SVC groups [OR of 3 family = 5.1289, PC (Bonferroni correction ) = 0.0002 and 5.9847, PC = 0.0001 and OR of 13 family = 4.6860, PC = 0.0002 and OR = 6.5987, PC = 0.0001 respectively]. While DRB1*040501, DRB1*040101, DRB1*7:01:01 and DRB1*110101 alleles were more frequent in SVC group than CHC patients (OR = 0.4052, PC = 0.03, OR: OR = 0.0916,PC = 0.0006, OR = 0.1833,PC = 0.0006 and OR = 0.4061, PC = 0.0001 respectively).

CONCLUSIONS

It was concluded that among the Egyptian families, HLA-DRB1*030101, and DRB1*130101 alleles associated with the risk of progression to CHC infection, while DRB1*040101, DRB1*040501, DRB1*7:01:01and DRB1*110101 act as protective alleles against HCV infection.

Identification of novel variants in HLA class II region related to HLA DPB1 expression and disease progression in patients with chronic hepatitis C

Recent genome-wide studies have demonstrated that HLA class II gene may play an important role in viral hepatitis. We studied genetic polymorphism and RNA expression of HLA class II genes in HCV-related liver diseases. The study was performed in groups consisting of 24 patients with HCV-related liver disease (12 of persistent normal ALT: PNALT group and 12 of advanced liver disease: ALD group) and 26 patients without HCV infection (control group). In PBMC samples, RNA expression of HLA class II genes (HLA-DPA1, DPB1, DQA1, DQB1, and DRB1) was analyzed by real-time RT-PCR. Furthermore, 22 single nucleotide polymorphisms (SNPs) in HLA class II gene and two SNPs in IL28B gene were genotyped by genetic analyzer (GENECUBE®). In expression analysis, only DPB1 level was significantly different. Mean expression level of DPB1gene in control group was 160.0, PNALT group 233.8, and ALD group 465.0 (P < 0.01). Of 24 SNPs, allele frequencies were statistically different in two SNPs (rs2071025 and rs3116996) between PNALT groups and ALD group (P < 0.01). In rs2071025, TT genotype was frequently detected in ALD group and expression level was significantly higher than the other genotypes (449.2 vs 312.9, P < 0.01). In rs3116996, TA or TT (non AA) genotype was frequently detected in ALD group and expression level was significantly higher than genotype AA (457.1 vs 220.9, P < 0.01). Genotyping and expression analysis in HLA class II gene revealed that two SNPs of HLA-DPB1 (rs2071025 and rs3116996) were significantly correlated to RNA expression and progression of HCV-related liver diseases.

KIR and HLA Genotypes Implicated in Reduced Killer Lymphocytes Immunity Are Associated with Vogt-Koyanagi-Harada Disease

Cytotoxic T lymphocytes (CTL) and natural killer (NK) cells are killer lymphocytes that provide defense against viral infections and tumor transformation. Analogous to that of CTL, interactions of killer-cell immunoglobulin-like receptors (KIR) with specific human leukocyte antigen (HLA) class I ligands calibrate NK cell education and response. Gene families encoding KIRs and HLA ligands are located on different chromosomes, and feature variation in the number and type of genes. The independent segregation of KIR and HLA genes results in variable KIR-HLA interactions in individuals, which may impact disease susceptibility. We tested whether KIR-HLA combinations are associated with Vogt-Koyanagi-Harada (VKH) disease, a bilateral granulomatous panuveitis that has strong association with HLA-DR4. We present a case control study of 196 VKH patients and 209 controls from a highly homogeneous native population of Japan. KIR and HLA class I genes were typed using oligonucleotide hybridization method and analyzed using two-tailed Fisher’s exact probabilities. The incidence of Bx-KIR genotypes was decreased in VKH patients (odds ratio [OR] 0.58, P = 0.007), due primarily to a decrease in centromeric B-KIR motif and its associated KIRs 2DS2, 2DL2, 2DS3, and 2DL5B. HLA-B22, implicated in poor immune response, was increased in VKH (OR = 4.25, P = 0.0001). HLA-Bw4, the ligand for KIR3DL1, was decreased in VKH (OR = 0.59, P = 0.01). The KIR-HLA combinations 2DL2+C1/C2 and 3DL1+Bw4, which function in NK education, were also decreased in VKH (OR = 0.49, P = 0.012; OR = 0.59, P = 0.013). Genotypes missing these two inhibitory KIR-HLA combinations in addition to missing activating KIRs 2DS2 and 2DS3 were more common in VKH (OR = 1.90, P = 0.002). These results suggest that synergistic hyporesponsiveness of NK cells (due to poor NK education along with missing of activating KIRs) and CTL (due to HLA-B22 restriction) fail to mount an effective immune response against viral-infection that may trigger VKH pathogenesis in genetically susceptible individuals, such as HLA-DR4 carriers.

Human Leukocyte Antigen Class II Alleles Are Associated with Hepatitis C Virus Natural Susceptibility in the Chinese Population

Human leukocyte antigen (HLA) class II molecule influences host antigen presentation and anti-viral immune response. The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) within HLA class II gene were associated with different clinical outcomes of hepatitis C virus (HCV) infection. Three HLA class II SNPs (rs3077, rs2395309 and rs2856718) were genotyped by TaqMan assay among Chinese population, including 350 persistent HCV infection patients, 194 spontaneous viral clearance subjects and 973 HCV-uninfected control subjects. After logistic regression analysis, the results indicated that the rs2856718 TC genotype was significantly associated with the protective effect of the HCV natural susceptibility (adjusted OR: 0.712, 95% CI: 0.554–0.914) when compared with reference TT genotype, and this remained significant after false discovery rate (FDR) correction (p = 0.024). Moreover, the protective effect of rs2856718 was observed in dominant genetic models (adjusted OR: 0.726, 95% CI: 0.574–0.920), and this remained significant after FDR correction (p = 0.024). In stratified analysis, a significant decreased risk was found in rs2856718C allele in the male subgroup (adjusted OR: 0.778, 95% CI: 0.627–0.966) and hemodialysis subgroup (adjusted OR: 0.713, 95% CI: 0.552–0.921). Our results indicated that the genetic variations of rs2856718 within the HLA-DQ gene are associated with the natural susceptibility to HCV infection among the Chinese population.

Naturally occurring mutations in the nonstructural region 5B of hepatitis C virus (HCV) from treatment-naïve Korean patients chronically infected with HCV genotype 1b

The nonstructural 5B (NS5B) protein of the hepatitis C virus (HCV) with RNA-dependent RNA polymerase (RdRp) activity plays a pivotal role in viral replication. Therefore, monitoring of its naturally occurring mutations is very important for the development of antiviral therapies and vaccines. In the present study, mutations in the partial NS5B gene (492 bp) from 166 quasispecies of 15 genotype-1b (GT) treatment-naïve Korean chronic patients were determined and mutation patterns and frequencies mainly focusing on the T cell epitope regions were evaluated. The mutation frequency within the CD8+ T cell epitopes was significantly higher than those outside the CD8+ T cell epitopes. Of note, the mutation frequency within predicted CD4+ T cell epitopes, a particular mutational hotspot in Korean patients was significantly higher than it was in patients from other areas, suggesting distinctive CD4+ T cell-mediated immune pressure against HCV infection in the Korean population. The mutation frequency in the NS5B region was positively correlated with patients with carrier-stage rather than progressive liver disease (chronic hepatitis, liver cirrhosis and hepatocellular carcinoma). Furthermore, the mutation frequency in four codons (Q309, A333, V338 and Q355) known to be related to the sustained virological response (SVR) and end-of treatment response (ETR) was also significantly higher in Korean patients than in patients from other areas. In conclusion, a high degree of mutation frequency in the HCV GT-1b NS5B region, particularly in the predicted CD4+ T cell epitopes, was found in Korean patients, suggesting the presence of distinctive CD4+ T cell pressure in the Korean population. This provides a likely explanation of why relatively high levels of SVR after a combined therapy of pegylated interferon (PEG-IFN) and ribavirin (RBV) in Korean chronic patients with GT-1b infections are observed.

HLA-DQB1*03 confers susceptibility to chronic hepatitis C in Japanese: a genome-wide association study

Hepatitis C virus (HCV) establishes a chronic infection in 70-80% of infected individuals. Many researchers have examined the effect of human leukocyte antigen (HLA) on viral persistence because of its critical role in the immune response against exposure to HCV, but almost all studies have proven to be inconclusive. To identify genetic risk factors for chronic HCV infection, we analyzed 458,207 single nucleotide polymorphisms (SNPs) in 481 chronic HCV patients and 2,963 controls in a Japanese cohort. Next, we performed a replication study with an independent panel of 4,358 cases and 1,114 controls. We further confirmed the association in 1,379 cases and 25,817 controls. In the GWAS phase, we found 17 SNPs that showed suggestive association (P < 1 × 10^-5). After the first replication study, we found one intronic SNP in the HLA-DQ locus associated with chronic HCV infection, and when we combined the two studies, the association reached the level of genome-wide significance. In the second replication study, we again confirmed the association (P_combined = 3.59 × 10⁻¹⁶, odds ratio [OR] = 0.79). Subsequent analysis revealed another SNP, rs1130380, with a stronger association (OR=0.72). This nucleotide substitution causes an amino acid substitution (R55P) in the HLA-DQB1 protein specific to the DQB1*03 allele, which is common worldwide. In addition, we confirmed an association with the previously reported IFNL3-IFNL4 locus and propose that the effect of DQB1*03 on HCV persistence might be affected by the IFNL4 polymorphism. Our findings suggest that a common amino acid substitution in HLA-DQB1 affects susceptibility to chronic infection with HCV in the Japanese population and may not be independent of the IFNL4 genotype.

Divergent contributions of regulatory T cells to the pathogenesis of chronic hepatitis C

Hepatitis C virus, a small single-stranded RNA virus, is a major cause of chronic liver disease. Resolution of primary hepatitis C virus infections depends upon the vigorous responses of CD4(+) and CD8(+) T cells to multiple viral epitopes. Although such broad CD4(+) and CD8(+) T-cell responses are readily detected early during the course of infection regardless of clinical outcome, they are not maintained in individuals who develop chronic disease. Purportedly, a variety of factors contribute to the diminished T-cell responses observed in chronic, virus-infected patients including the induction of and biological suppression by CD4(+)FoxP3(+) regulatory T cells. Indeed, a wealth of evidence suggests that regulatory T cells play diverse roles in the pathogenesis of chronic hepatitis C, impairing the effector T-cell response and viral clearance early during the course of infection and suppressing liver injury as the disease progresses. The factors that affect the generation and biological response of regulatory T cells in chronic, hepatitis C virus-infected patients is discussed.

A genome-wide association study of HCV-induced liver cirrhosis in the Japanese population identifies novel susceptibility loci at the MHC region

BACKGROUND & AIMS

We performed a genome-wide association study (GWAS) of hepatitis C virus (HCV)-induced liver cirrhosis (LC) to identify predictive biomarkers for the risk of LC in patients with chronic hepatitis C (CHC).

METHODS

A total of 682 HCV-induced LC cases and 1045 CHC patients of Japanese origin were genotyped by Illumina Human Hap 610-Quad bead Chip.

RESULTS

Eight SNPs which showed possible associations (p<1.0 × 10(-5)) at the GWAS stage were further genotyped using 936 LC cases and 3809 CHC patients. We found that two SNPs within the major histocompatibility complex (MHC) region on chromosome 6p21, rs910049 and rs3135363, were significantly associated with the progression from CHC to LC (pcombined=9.15 × 10(-11) and 1.45 × 10(-10), odds ratio (OR)=1.46 and 1.37, respectively). We also found that HLA-DQA1(*)0601 and HLA-DRB1(*)0405 were associated with the progression from CHC to LC (p=4.53 × 10(-4) and 1.54 × 10(-4) with OR=2.80 and 1.45, respectively). Multiple logistic regression analysis revealed that rs3135363, rs910049, and HLA-DQA1(*)0601 were independently associated with the risk of HCV-induced LC. In addition, individuals with four or more risk alleles for these three loci have a 2.83-fold higher risk for LC than those with no risk allele, indicating the cumulative effects of these variations.

CONCLUSIONS

Our findings elucidated the crucial roles of multiple genetic variations within the MHC region as prognostic/predictive biomarkers for CHC patients.

Altered expressions of peripheral CD11c, CD80, CD83 markers and associations of HLA class II allele and haplotypes in self-limiting Hepatitis E infection

Hepatitis E virus (HEV), the major cause of self limiting viral hepatitis, is associated with a robust humoral, moderate CD4 T cell and CTL response. However, key questions like the probable involvement of HLA class II alleles and peripheral DCs/monocytes in regulating the innate and adaptive immune responses in Hepatitis E remain unanswered. One eighty four self- limiting Hepatitis E patients and 283 anti-HEV negative controls from Western India were studied for the distribution of HLA class II alleles and the frequencies of peripheral CD80, CD83, CD86, HLA-DR and CD11c by PCR SSP method and flow cytometry respectively. Frequency of DRB1(∗)11 allele group was significantly low while haplotypes DRB1(∗)15/DQB1(∗)06 and DRB1(∗)10/DQB1(∗)05 were significantly high in the patient population. CD11c, CD80 and CD83 expressions were high in the patient groups. CD11c expression was positively associated with viral load. CD86 expression was significantly low in the patients having DQB1(∗)06 allele. Association of HLA-DRB1(∗)11 and the emergence of DRB1(∗)15/DQB1(∗)06 and DRB1(∗)10/DQB1(∗)05 as susceptible haplotypes towards HEV infection is being reported for the first time. Positive correlation of CD11c with HEV viral load suggested that increased frequencies of the same might be associated with HEV replication.

Protective effect of HLA-DRB1 11 and predisposition of HLA-C 04 in the development of severe liver damage in Brazilian patients with chronic hepatitis C virus infection

The objective of this study was to investigate human leucocyte antigen (HLA) genes in patients chronically infected with hepatitis C virus (HCV) and to analyse the possible role of these genes in the progression of chronic hepatitis C. One hundred and forty-five (145) Brazilian patients infected only with HCV genotype 1 were evaluated. HLA class I (A, B, C) and class II (DRB1, DQA1, DQB1) typing were carried out by PCR-SSO, through Luminex technology. Associations were found with protection against development of liver damage by both DRB1 11 (5.0% versus 18.2%, P=0.0016, OR=0.23, CI 95% = 0.09-0.58; Pc=0.0208) and DRB1 11-DQA1 05-DQB1 03 haplotype (4.2% versus 15.3%, P=0.0032; OR = 0.24, CI 95% = 0.08-0.64). Liver damage was associated with HLA-C 04 in patients with <20 years of infection (38.4% versus 9.1%, P = 0.002, OR = 6.25, CI 95%=1.97-19.7; Pc=0.0238). It is concluded that HLA alleles can influence the development of liver damage in HCV type-1 chronically infected Brazilian patients.

Dendritic cells, regulatory T cells and the pathogenesis of chronic hepatitis C

Hepatitis C virus (HCV) is a small, enveloped RNA virus and a major cause of chronic liver disease. Resolution of primary HCV infections depends upon the vigorous responses of CD4⁺ and CD8⁺ T cells to multiple viral epitopes. Although such broad-based responses are readily detected early during the course of infection regardless of clinical outcome, they are not maintained in individuals who develop chronic disease. Ostensibly, a variety of factors contribute to the diminished T cell responses observed in chronic, HCV-infected patients including impaired dendritic cell function and the induction of CD4⁺FoxP3⁺ regulatory T cells. Overwhelming evidence suggests that the complex interaction of dendritic cells and regulatory T cells plays a critical role in the pathogenesis of chronic hepatitis C.

DLA class II alleles and haplotypes are associated with risk for and protection from chronic hepatitis in the English Springer spaniel

Chronic hepatitis (CH) is common in dogs in the United Kingdom. An increased prevalence of the disease is seen in the English Springer spaniel (ESS), and this breed suffer from a severe form with young to middle aged female dogs being predisposed. The disease shares histological features with those of human viral hepatitis, although the specific aetiological agent has not yet been identified. The aim of the current study was to investigate whether dog leucocyte antigen (DLA) class II alleles and haplotypes are associated with susceptibility/resistance to CH in the ESS. Sequence-based genotyping of the polymorphic exon 2 from DLA-DRB1, -DQA1 and -DQB1 class II loci were performed in 66 ESSs with CH and 84 healthy controls. There was a significant difference in the distribution of the protective alleles DRB1*00501 (3.0% vs. 12.0%, odds ratio [OR] = 0.23, 95% confidence interval [CI] = 0.06–0.74) and DQB1*00501 (3.8% vs. 12.0%, OR = 0.29, 95% CI = 0.09–0.85) between cases and controls. The haplotype DLA-DRB1*00501/DQA1*00301/DQB1*00501 was present in 11.9% of controls and 3.0% of cases and was significantly associated with protection against disease development (OR = 0.26, 95% CI = 0.08–0.80). There was a significant difference in the distribution of the risk alleles DRB1*00601 (14.4% vs. 6.5%, OR = 2.40, 95% CI = 1.10–5.63) and DQB1*00701 (14.4% vs. 6.5%, OR = 2.40, 95% CI = 1.10–5.63) between cases and controls. A risk haplotype (DLA-DRB1*00601/DQA1*005011/DQB1*00701) was present in 14.4% of cases and 6.5% of controls and conferred an elevated risk of developing CH with an OR of 3.13 (95% CI = 1.20–8.26). These results demonstrate that DLA class II is significantly associated with risk and protection from developing CH in ESSs.

Correlations of CTLA-4 gene polymorphisms and hepatitis C chronic infection

BACKGROUND

Cytotoxic T lymphocyte-associated factor 4 (CTLA-4) functions as a negative regulator of T cell-mediated immune response. Molecular changes associated to CTLA-4 gene polymorphisms could reduce its ability to suppress and control lymphocyte proliferation.

AIMS

To evaluate the frequency of CTLA-4 gene polymorphisms in chronic hepatitis C virus (HCV) infected patients and correlate to clinical and histological findings.

METHODS

We evaluated 112 HCV-infected subjects prospectively selected and 183 healthy controls. Clinical and liver histological data were analysed. -318C > T, A49G and CT60 CTLA-4 single-nucleotide polymorphisms (SNPs) were studied by PCR-RFLP and AT(n) polymorphism by DNA fragment analysis by capillary electrophoresis in automatic sequencer.

RESULTS

Eight AT repetitions in 3'UTR region were more frequent in HCV-infected subjects. We found a positive association of -318C and + 49G with HCV genotype 3 (P = 0.008, OR 9.13, P = 0.004, OR 2.49 respectively) and an inverse association of both alleles with HCV genotype 1 (P = 0.020, OR 0.19, P = 0.002, OR 0.38 respectively). Allele + 49G was also associated to aminotransferases quotients > 3 (qALT, P = 0.034, qAST, P = 0.041). Allele G of CT60 SNP was also associated with qAST > 3 (P = 0.012). Increased number of AT repetitions was positively associated to severe necroinflammatory activity scores in liver biopsies (P = 0.045, OR 4.62).

CONCLUSION

CTLA-4 gene polymorphisms were associated to HCV-infection. Eight AT repetitions were more prevalent in HCV-infected subjects. -318C and + 49G alleles were associated to genotypes 1 and 3 infections and increased number of AT repetitions in 3'UTR region favoured severe necroinflammatory activity scores in liver biopsies.

Human leukocyte antigen class II molecules confer both susceptibility and progression in Japanese patients with primary biliary cirrhosis

Along with twin and family studies, recent genome-wide association studies suggest that genetic factors contribute to the susceptibility and severity of primary biliary cirrhosis (PBC). Although several reports have demonstrated that the human leukocyte antigen (HLA) DRB1*08:03 allele is associated with disease susceptibility in Japan, the precise analysis of HLA haplotypes and the role of amino acid alignment have not been fully clarified. We investigated HLA class I A, B, and C and HLA class II DRB1 and DQB1 alleles and haplotypes in 229 Japanese patients with PBC and compared them with the published data of 523 healthy subjects. Significant associations were found with PBC susceptibility for the DRB1*08:03-DQB1*06:01 (13% versus 6%; P = 0.000025; odds ratio [OR] = 2.22) and DRB1*04:05-DQB1*04:01 haplotypes (17% versus 13%; P = 0.044; OR = 1.38). Conversely, there were significant protective associations with the DRB1*13:02-DQB1*06:04 (2% versus 5%; P = 0.00093; OR = 0.27) and DRB1*11:01-DQB1*03:01 haplotypes (1% versus 4%; P = 0.03; OR = 0.37). The frequency of the DRB1*09:01-DQB1*03:03 haplotype was significantly higher in patients who had received orthotopic liver transplantation (33% versus 11%; P = 0.0012; OR = 3.96). Furthermore, the frequency of serine at position 57 (P = 0.0000015; OR = 1.83) of the DRβchain differed the most in patients with PBC, compared with healthy subjects.

CONCLUSION

This study established the role of HLA haplotypes in determining PBC susceptibility and progression in the Japanese population. Further resequencing of the HLA region is required to more precisely identify the genetic components of PBC.

Influence of HLA alleles in response to treatment with pegylated interferon-alpha and ribavirin in patients with chronic hepatitis C

The objective of this study was to analyse the possible role of HLA polymorphism of chronically infected hepatitis C virus patients in the response outcome to treatment with pegylated interferon-alpha plus ribavirin. To that end, 144 Brazilian patients infected only with genotype 1 of the virus were treated with pegylated interferon-alpha at 1.5 μg kg(-1) in conjunction with ribavirin (1000 mg if patient weight was <75 kg and 1250 mg if >75 kg) for 48 weeks. The patients did not have concomitant HBV or HIV infections or liver disease, did not undergo previous antiviral treatment, and were followed up for 24 weeks after the end of treatment to assure they presented a sustained virological response. Patients were classified according to response to treatment in responsive (SVR), nonresponsive (NRS) and relapsers (REL). HLA class I and class II typing were carried out through PCR-SSO using Luminex technology. A statistically higher frequency of DRB1*11 patients was observed in the SVR group (39.6% vs. 14.3%P = 0.0012; Pc = 0.0156; OR = 3.94; 95% CI = 1.8-8.8). HLA-DQB1*03 patients were also more frequent in the SVR group, but the P value lost significance after Bonferroni correction (62.3% vs. 41.7%P = 0.024; Pc = 0.14, OR = 2.3; 95% CI = 1.14-4.60). HLA class II antigens can positively influence the response to treatment with pegylated interferon-alpha and ribavirin.

HLA class II alleles and chronic hepatitis C virus infection

The aim of this study was to investigate association of human leucocyte antigens (HLA)-DRB1 and DQB1 polymorphisms with hepatitis C virus (HCV) infection and with the occurrence of severe liver fibrosis/cirrhosis in chronically infected patients. Ninety-nine white patients, from southeast Brazil, with confirmed HCV chronic infection were included in the study. Severe fibrosis/cirrhosis (METAVIR scores F3-F4) was present in 49 patients. HLA-DRB1 specificities and DRB1*11 and DQB1* alleles were determined by PCR-SSP, and their frequencies were compared between patients and a control group of 103 healthy white Brazilian individuals. The results confirmed previous reports of the association of DRB1*11 and DQB1*03 with protection from chronic HCV infection, but did not confirm their association with protection from severe fibrosis/cirrhosis. Furthermore, the results suggested that the polymorphic sites on HLA molecules responsible for protection from chronic HCV infection are encoded not only by the DRB1*1101 and DQB1*0301, as suggested in the literature, but also by other DRB1*11 and DQB1*03 alleles. Thus, we hypothesized that the common polymorphic residues shared by different DRB1*11 and/or DQB1*03 alleles might be responsible for selection of viral epitopes for presentation to CD4(+) T cells, leading to an efficient immune response against the virus.

Type 1 diabetes and interferon therapy: a nationwide survey in Japan

OBJECTIVE

Interferon therapy can trigger induction of several autoimmune diseases, including type 1 diabetes. To assess the clinical, immunologic, and genetic characteristics of type 1 diabetes induced by interferon therapy, we conducted a nationwide cross-sectional survey.

RESEARCH DESIGN AND METHODS

Clinical characteristics, anti-islet autoantibodies, and HLA-DR typing were examined in 91 patients for whom type 1 diabetes developed during or shortly after interferon therapy.

RESULTS

Median age at the onset of type 1 diabetes was 56 (interquartile range 48-63) years and mean ± SD BMI was 20.8 ± 2.7 kg/m(2). The time period from the initiation of interferon therapy to type 1 diabetes onset in patients receiving pegylated interferon and ribavirin was significantly shorter than that in patients with nonpegylated interferon single therapy (P < 0.05). Anti-islet autoantibodies were detected in 94.5% of patients at diabetes onset. Type 1 diabetes susceptibility HLA-DRs in the Japanese population, DR4 and DR9, were also associated with interferon treatment-related type 1 diabetes. Furthermore, the prevalence of HLA-DR13 was significantly higher in interferon treatment-related type 1 diabetes than in healthy control subjects (odds ratio 3.80 [95% CI 2.20-7.55]; P < 0.0001) and classical type 1 diabetes (2.15 [1.17-3.93]; P < 0.05).

CONCLUSIONS

Anti-islet autoantibodies should be investigated before and during interferon therapy to identify subjects at high risk of type 1 diabetes. Stronger antiviral treatment may induce earlier development of type 1 diabetes. Furthermore, patients who develop interferon-induced type 1 diabetes are genetically susceptible.

The relation of HLA genotype to hepatitis C viral load and markers of liver fibrosis in HIV-infected and HIV-uninfected women

BACKGROUND

Human leukocyte antigen (HLA) class I and II genotype is associated with clearance of hepatitis C virus (HCV) infection, but little is known regarding its relation with HCV viral load or risk of liver disease in patients with persistent HCV infection.

METHODS

High-resolution HLA class I and II genotyping was conducted in a prospective cohort of 519 human immunodeficiency virus (HIV)-seropositive and 100 HIV-seronegative women with persistent HCV infection. The end points were baseline HCV viral load and 2 noninvasive indexes of liver disease, fibrosis-4 (FIB-4), and the aspartate aminotransferase to platelet ratio index (APRI), measured at baseline and prospectively.

RESULTS

DQB1*0301 was associated with low baseline HCV load (β = -.4; 95% confidence interval [CI], -.6 to -.3; P < .00001), as well as with low odds of FIB-4-defined (odds ratio [OR], .5; 95% CI, .2-.9; P = .02) and APRI-defined liver fibrosis (OR, .5; 95% CI, .3-1.0; P = .06) at baseline and/or during follow-up. Most additional associations with HCV viral load also involved HLA class II alleles. Additional associations with FIB-4 and APRI primarily involved class I alleles, for example, the relation of B*1503 with APRI-defined fibrosis had an OR of 2.0 (95% CI, 1.0-3.7; P = .04).

CONCLUSIONS

HLA genotype may influence HCV viral load and risk of liver disease, including DQB1*0301, which was associated with HCV clearance in prior studies.

Dysfunction of Immune Systems and Host Genetic Factors in Hepatitis C Virus Infection with Persistent Normal ALT

Patients with chronic hepatitis C (CHC) virus infection who have persistently normal alanine aminotransferase levels (PNALT) have mild inflammation and fibrosis in comparison to those with elevated ALT levels. The cellular immune responses to HCV are mainly responsible for viral clearance and the disease pathogenesis during infection. However, since the innate and adaptive immune systems are suppressed by various kinds of mechanisms in CHC patients, the immunopathogenesis of CHC patients with PNALT is still unclear. In this review, we summarize the representative reports about the immune suppression in CHC to better understand the immunopathogenesis of PNALT. Then, we summarize and speculate on the immunological aspects of PNALT including innate and adaptive immune systems and genetic polymorphisms of HLA and cytokines.

Cytokine and apoptosis gene polymorphisms influence the outcome of hepatitis C virus infection

BACKGROUND

Hepatitis C virus (HCV) infection is thought to be chronic and the factors leading to viral clearance or persistence are poorly understood. This study was undertaken to investigate the possibility of a significant relationship between the spontaneous clearance or the persistence of hepatitis C virus (HCV) infection and cytokine and apoptosis gene polymorphisms in Tunisian patients on hemodialysis.

METHODS

Polymorphisms of the genes IL-1 (-889 IL-1alpha, -511 and +3954 IL-1beta, IL-1Ra), IL-18 (-137 and -607), IL-12 (-1188) and Apo1/Fas (-670) were determined by PCR-RFLP, PCR-SSP and PCR-VNTR in 100 healthy blood donors and 100 patients infected with HCV and undergoing hemodialysis. The patients were classified into two groups: G1 consisted of 76 active chronic hepatitis patients (positive for HCV RNA) and G2 consisted of 24 hemodialysed patients who spontaneously eliminated the virus (negative for HCV RNA).

RESULTS

The frequency of genotype association [-137GC/-607CA] IL-18 was higher in G2 (41.7%) than in G1 (15.8%) (P=0.008; OR=0.26; 95% CI, 0.10-0.73). We also found a higher frequency of the AA genotype of the Apo1/Fas gene in G2 (41.6%) than in G1 (17.5%) (P=0.026; OR=3.49; 95% CI, 1.13-10.69). Adjustment for known covariate factors (age, gender and genotype) confirmed these univariate findings and revealed that the genotype association GC-CA of the (-137 and -607) IL-18 gene and the AA genotype of the Apo1/Fas gene were associated with the clearance of HCV (P=0.041 and 0.017, respectively).

CONCLUSION

The two genotypes GC-CA of the (-137 and -607) IL-18 polymorphism and the AA genotype of the Apo1/Fas gene influence the outcome of HCV infection in Tunisian patients on hemodialysis.

Possession of HLA class II DRB1*1303 associates with reduced viral loads in chronic HIV-1 clade C and B infection

BACKGROUND

The HLA class II molecules play a central role in the generation of human immunodeficiency virus (HIV)-specific CD4(+) T-helper cells, which are critical for the induction of cytotoxic CD8(+) T cell responses. However, little is known about the impact of HLA class II alleles on HIV disease progression.

METHODS

In this study we investigated the effect of HLA class II alleles on HIV disease outcome and HIV-specific T cell responses in a cohort of 426 antiretroviral therapy-naive, HIV-1 clade C-infected, predominantly female black South Africans.

RESULTS

The HLA class II allele DRB1*1303 was independently associated with lower plasma viral loads in this population (P = .02), an association that was confirmed in a second cohort of 1436 untreated, HIV-1 clade B-infected, male European Americans, suggesting that DRB1*1303-mediated protection is independent of ethnicity, sex, and viral clade. Interestingly, DRB1*1303 carriage was not associated with an increased frequency of interferon (IFN) γ-positive HIV-specific CD4(+) T cell responses.

CONCLUSIONS

These data demonstrate the independent effect of an HLA class II allele, DRB1*1303, on HIV disease progression, in the absence of increased IFN-γ-positive HIV-specific CD4(+) T cell frequencies, suggesting that the protective activity of DRB1*1303 may be mediated via an alternative mechanism.

Association of human leucocyte antigen Class I (HLA-A and HLA-B) with chronic hepatitis C virus infection in Egyptian patients

Egypt has the highest prevalence of hepatitis C virus (HCV) in the world, ranging from 6% to 28% with an average of approximately 13.8% in the general population. It has been reported that human leucocyte antigen (HLA) alleles are associated with the outcome of HCV infection, but this associations showed ethnic and geographical differences. The objective of this study is to investigate the association between the frequencies of HLA Class I and chronic HCV infection in Egyptian patients and to find out whether there is a relation between certain HLA Class I antigens and HCV viral load, degree of fibrosis, activity and alanine aminotransferase (ALT) level. A case control study was conducted on 100 patients with chronic HCV infection and 150 healthy controls. HLA-A and HLA-B typing by complement-dependent micro-lympho-cytotoxicity assay was performed for both groups. HLA-A11 antigen was significantly increased in patients with chronic HCV infection versus controls (OR 3.98; 95% CI = 1.85-8.89; P = 0.001; and Pc = 0.021). HLA-B12, HLA-B13, HLA-B17 and HLA-B40 were higher in patients, and HLA-A32 and HLA-B14 were higher in controls, although the significance was lost after correction for multiple testing. HLA-A9 was significantly associated with low viral load (P = 0.008, Pc = 0.048). The results of this work implicate that HLA-A11 antigen may influence chronic HCV infection and may play a role in viral persistence. Different HLA Class I antigens are not associated with degree of liver fibrosis, grades of activity or level of ALT. However, HLA-A9 is associated with low HCV viral load in chronic HCV Egyptian patients.

An Assessment of the Use of Chimpanzees in Hepatitis C Research Past, Present and Future: 2. Alternative Replacement Methods

The use of chimpanzees in hepatitis C virus (HCV) research was examined in the report associated with this paper ( 1: Validity of the Chimpanzee Model), in which it was concluded that claims of past necessity of chimpanzee use were exaggerated, and that claims of current and future indispensability were unjustifiable. Furthermore, given the serious scientific and ethical issues surrounding chimpanzee experimentation, it was proposed that it must now be considered redundant — particularly in light of the demonstrable contribution of alternative methods to past and current scientific progress, and the future promise that these methods hold. This paper builds on this evidence, by examining the development of alternative approaches to the investigation of HCV, and by reviewing examples of how these methods have contributed, and are continuing to contribute substantially, to progress in this field. It augments the argument against chimpanzee use by demonstrating the comprehensive nature of these methods and the valuable data they deliver. The entire life-cycle of HCV can now be investigated in a human (and much more relevant) context, without recourse to chimpanzee use. This also includes the testing of new therapies and vaccines. Consequently, there is no sound argument against the changes in public policy that propose a move away from chimpanzee use in US laboratories.

Relationship between host genetic polymorphisms and the outcome of hepatitis C virus infection

Acute hepatitis C virus (HCV) infection can induce host innate and adaptive immune responses. Approximately 15%-25% of HCV-infected patients successfully eliminated the virus whereas the majority of these patients developed chronic liver disease, cirrhosis and hepatocellular carcinoma. Numerous studies have demonstrated that host genetic polymorphisms may lead to differences in host immune function and therefore influence the clinical outcome of HCV infection. This review briefly summarizes the relationship between host genetic polymorphisms and the outcome of HCV infection.

Hepatitis C virus NS4 protein impairs the Th1 polarization of immature dendritic cells

Dendritic cells (DCs) in chronic hepatitis C patients display impaired function, although the details remain unclear. To investigate the hepatitis C virus (HCV) protein that has the most impact on DC function, we compared five recombinant proteins and seven HCV protein genes in modulating DC phenotype and function. Immature DCs (iDCs) were established from healthy donor peripheral blood monocytes with granulocyte-macrophage colony stimulating factor (GM-CSF) and IL-4. Lipopolysaccharide was used to establish mature DCs (mDCs). Cells were then pulsed with HCV recombinant proteins or transfected with HCV plasmids and subsequently assayed for cell surface marker expression by flow cytometry. For cytokine and proliferative T-cell response analysis, DCs were cultured with autologous CD4 T cells and tuberculin purified protein derivative (PPD). Mean fluorescent intensity of CD86 was reduced in HCV protein-pulsed iDCs. Proliferative T-cell responses and Th1 cytokine concentrations were reduced with HCV nonstructural proteins (NS), particularly with HCV NS4. HCV nonstructural proteins, particularly NS4, change the iDC phenotype and reduce antigen-specific T-cell stimulatory function with Th1 cytokine reductions.

Human leukocyte antigen class I and II alleles in non-Hodgkin lymphoma etiology

Genome-wide association and candidate gene studies implicate different genetic variants within the 6p21 chromosomal region with different non-Hodgkin lymphoma (NHL) subtypes. Complementing these efforts, we conducted human leukocyte antigen (HLA) class I and class II genotyping among 610 NHL cases and 555 controls of non-Hispanic white descent from a US multicenter study. Allele-disease associations were assessed by logistic regression for NHL and its subtypes. Statistically significant associations between HLA and NHL subtypes include HLA-DRB1*0101 for follicular lymphoma (odds ratio [OR] = 2.14, P < .001), HLA-DRB1*0401 for diffuse large B-cell lymphoma (DLBCL; OR = 0.45, P = .006), and HLA-DRB1*13 and follicular lymphoma (OR = 0.48, P = .008). We further observed significant heterozygote advantage for HLA class I alleles and NHL, and particularly DLBCL (P trend = .01 for elevated risk with increasing number of homozygous alleles). Our results support a role for HLA in the etiology of NHL and its subtypes.

Specific human leukocyte antigen class I and II alleles associated with hepatitis C virus viremia

Studies of human leukocyte antigen (HLA) alleles and their relation with hepatitis C virus (HCV) viremia have had conflicting results. However, these studies have varied in size and methods, and few large studies assessed HLA class I alleles. Only one study conducted high-resolution class I genotyping. The current investigation therefore involved high-resolution HLA class I and II genotyping of a large multiracial cohort of U.S. women with a high prevalence of HCV and HIV. Our primary analyses evaluated associations between 12 HLA alleles identified through a critical review of the literature and HCV viremia in 758 HCV-seropositive women. Other alleles with >5% prevalence were also assessed; previously unreported associations were corrected for multiple comparisons. DRB1*0101 (prevalence ratio [PR] = 1.7; 95% confidence interval [CI] = 1.1-2.6), B*5701 (PR=2.0; 95% CI = 1.0-3.1), B*5703 (PR = 1.7; 95% CI = 1.0-2.5), and Cw*0102 (PR = 1.9; 95% CI = 1.0-3.0) were associated with the absence of HCV RNA (i.e., HCV clearance), whereas DRB1*0301 (PR = 0.4; 95% CI = 0.2-0.7) was associated with HCV RNA positivity. DQB1*0301 was also associated with the absence of HCV RNA but only among HIV-seronegative women (PR = 3.4; 95% CI = 1.2-11.8). Each of these associations was among those predicted. We additionally studied the relation of HLA alleles with HCV infection (serostatus) in women at high risk of HCV from injection drug use (N = 838), but no significant relationships were observed.

CONCLUSION

HLA genotype influences the host capacity to clear HCV viremia. The specific HLA associations observed in the current study are unlikely to be due to chance because they were a priori hypothesized.

Patient HLA-DRB1* and -DQB1* allele and haplotype association with hepatitis C virus persistence and clearance

Hepatitis C virus (HCV) infection is prevalent throughout the world and interferon (IFN)-based treatments are currently the only therapeutic option. However, depending upon variations in their human leukocyte antigen (HLA), some patients do not respond well to IFN therapy. The current study evaluated the HLA allele and haplotype distribution of 204 HCV-seropositive individuals from Islamabad, Pakistan, who were receiving standard IFN therapy. In this cohort, 150 patients (74%) showed a sustained virological response to IFN therapy, whereas 54 (26%) did not. In addition to the HCV patients, 102 unrelated healthy volunteers were used as controls. DNA was isolated from the blood of the patients and controls for HLA-DRB1 and HLA-DQB1 allele typing, whilst plasma was used for HCV detection and genotyping. HLA-DRB1*04 was found to impart a significant protective advantage [Bonferroni-corrected P value (pc)=0.047] against HCV infection. In patients on IFN therapy, HLA-DRB1*11 and -DQB1*0301 (pc=0.044) were found to be associated with viral clearance. In contrast, HLA-DRB1*07 (pc=0.008) individually or in combination with HLA-DQB1*02 was found to be associated with viral persistence. These associations of HLA with HCV persistence or clearance will be beneficial in deciding the therapeutic regimen for Pakistani patients infected with HCV genotype 3a.

Characterization of the cellular immune response in hepatitis C virus infection

Hepatitis C virus (HCV), a hepatotropic RNA virus, is a major causative agent of chronic hepatitis, liver cirrhosis, and hepatocellular carcinomas. The host immune responses, especially cellular immune responses, play an important role in viral clearance, liver injury, and persistent HCV infection. A thorough characterization of the HCV cellular immune responses is important for understanding the interplays between host immune system and viral components, as well as for developing effective therapeutic and prophylactic HCV vaccines. Recent advances that provide better understanding the cell immune responses in HCV infection are summarized in this article.

Enhanced ability of regulatory T cells in chronic hepatitis C patients with persistently normal alanine aminotransferase levels than those with active hepatitis

In hepatitis C virus (HCV) infection, the Th1-type immune response is involved in liver injury. A predominance of immunosuppressive regulatory T cells (Treg) is hypothesized in patients with persistently normal alanine aminotransferase (PNALT). Our aim was to clarify the role of Treg in the pathogenesis of PNALT. Fifteen chronically HCV-infected patients with PNALT, 21 with elevated ALT (CH) and 19 healthy subjects (HS) were enrolled. We determined naturally-occurring Treg (N-Treg) as CD4+CD25high+FOXP3+ T cells. The expression of FOXP3 and CTLA4 in CD4+CD25high+ cells was quantified by real-time reverse transcriptase-polymerase chain reaction. Bulk or CD25-depleted CD4+ T cells cultured with HCV-NS5 loaded dendritic cells were assayed for their proliferation and cytokine release. We examined CD127-CD25-FOXP3+ cells as distinct subsets other than CD25+ N-Treg. The frequencies of N-Treg in patients were significantly higher than those in HS. The FOXP3 and CTLA4 transcripts were higher in PNALT than those in CH. The depletion of CD25+ cells enhanced HCV-specific T cell responses, showing that co-existing CD25+ cells are suppressive. Such inhibitory capacity was more potent in PNALT. The frequency of CD4+CD127-CD25-FOXP3+ cells was higher in CH than those in PNALT. Treg are more abundant in HCV-infected patients, and their suppressor ability is more potent in patients with PNALT than in those with active hepatitis.

Immunogenetics of drug-induced skin blistering disorders. Part II: Synthesis

The overall immunopathogenesis relevant to a large series of disorders caused by a drug or its associated hyperimmune condition is discussed based upon examining the genetics of severe drug-induced bullous skin problems (sporadic idiosyncratic adverse events including Stevens–Johnson syndrome and Toxic epidermal necrolysis). New results from an exemplar study on shared precipitating and perpetuating inner causes with other related disease phenotypes including aphtous stomatitis, Behçets, erythema multiforme, Hashimoto’s thyroiditis, pemphigus, periodic fevers, Sweet’s syndrome and drug-induced multisystem hypersensitivity are presented. A call for a collaborative, wider demographic profiling and deeper immunotyping in suggested future work is made.

The history of the "natural history" of hepatitis C (1968-2009)

In the late 1960's, only types A and B hepatitis were believed to exist, distinguished by circumstances of exposure and incubation periods. In the early 1970's, studies of transfusion recipients were begun with the belief that hepatitis B would be responsible should transfusion-associated hepatitis develop. After discovery of the viruses of hepatitis A and B, neither agent was found responsible, hence non-A, non-B (NANB) hepatitis. Initial follow-up of these cases showed that approximately 50% developed chronic hepatitis based on persistence of serum enzymes for at least 6 months. Approximately 15 years later, after the hepatitis C virus had been identified as the cause for NANB hepatitis, chronic hepatitis was found to develop more frequently as indicated by persistent viral infection in over 80% of infected adults but in only about 50% of infected children or young women. Follow-up over 2 to 4 decades indicated that many infected persons developed progressive hepatic fibrosis, sometimes culminating in cirrhosis and/or liver cancer. Long-term natural history studies have proved to be challenging because disease onset is often silent and progression extremely slow. Differing strategies have been used to determine the natural history, the descriptions and results of which are presented in this review.

Molecular and contextual markers of hepatitis C virus and drug abuse

The spread of hepatitis C virus (HCV) infection involves a complex interplay of social risks, and molecular factors of both virus and host. Injection drug abuse is the most powerful risk factor for HCV infection, followed by sexual transmission and additional non-injection drug abuse factors such as co-infection with other viruses and barriers to treatment. It is clearly important to understand the wider context in which the factors related to HCV infection occur. This understanding is required for a comprehensive approach leading to the successful prevention, diagnosis, and treatment of HCV. An additional consideration is that current treatments and advanced molecular methods are generally unavailable to socially disadvantaged patients. Thus, the recognition of behavioral/social, viral, and host factors as components of an integrated approach to HCV is important to help this vulnerable group. Equally important, this approach is key to the development of personalized patient treatment - a significant goal in global healthcare. In this review, we discuss recent findings concerning the impact of drug abuse, epidemiology, social behavior, virology, immunopathology, and genetics on HCV infection and the course of disease.

HLA-class II alleles in Egyptian patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is linked to environmental, dietary, and life style factors. Its incidence and distribution vary widely among ethnic groups, sex, and geographic regions. HBV and HCV Infection, liver cirrhosis, male gender, and old age are important risk factors of HCC. Variability in outcome following exposure, and the clustering of HCC within families raise the possibility that genetic factors are also involved in susceptibility to HCC. The Major Histocompatibility Complex (MHC) plays a key role in anti-virus and tumor defense. HLA polymorphism is implicated in conferring genetic susceptibility to a large number of immune-mediated diseases, including some cancers. The association between HLA class II antigen and HCC in different ethnic populations that has been reported is controversial. Therefore, the aim of this work was to study the association between HLA class II-DRB1 and DQB1 polymorphism and HCC in Egyptian patients and to investigate their role as risk factors for the development of HCC.

METHODS

HLA-class II (DRB1 and DQB1) typing was done by SSP for 100 subjects; 50 patients suffering from HCC (45 males and 5 females) with age range 40-64 years (51.16 years (y) +/- 6.16); and 50 normal healthy control subjects.

RESULTS

1. A significantly increased frequency of DRB1*04, and DQB1 *02 in HCC patients versus control group (p = 0.016, and 0.032, respectively) was found; 2. A significantly decreased frequency of DQB1*06 (p = 0.032) was found; 3. A significantly increased frequency of DRB1*07 (odds ratio (OR) = 4.929) was found; and 4. A significantly decreased frequency of DRB1*15 (OR = 0.316) was seen. In conclusion, while some alleles are significantly associated with HCC (DRB1*04, DQB1*02) and others are not associated (DQB1*06); therefore, it can be concluded that the DRB1*04 and DQB1*02 alleles might be risk factors for the occurrence of HCC (OR = 4.373 and 3.807, respectively), and DQB1*06 may be a protective allele (OR = 0.259).

Polymorphism in the human major histocompatibility complex and early viral decline during treatment of chronic hepatitis C

The dynamics of the viral decline immediately after the start of therapy for chronic hepatitis C virus (HCV) infection may have prognostic potential for ultimate sustained virologic response. Considerable interindividual variability in the decline has been reported, including differences by race. The human major histocompatability complex (MHC) genes encode the human leukocyte antigens, which are important in the immune response to viral infections. We examined whether carriage of specific human MHC alleles are associated with the rate of the early viral decline. Longitudinal viral level data (baseline and days 1, 2, 7, 14, and 28 of treatment), medium resolution MHC genotyping, and random coefficients models were used to examine associations between MHC class I and class II allele carriage and the dynamics of the viral decline in 180 African-Americans (AAs) and 194 Caucasian Americans (CAs) with genotype-1 HCV infection over the first 28 days of treatment with peginterferon alpha2a plus ribavirin. Baseline viral levels were similar by race, irrespective of allele carriage. However, the rate of change in the viral decline was associated with both allele and race. Among the four subgroups defined by race and specific allele, the fastest rates of decline were observed (in terms of estimated mean viral declines log(10) IU/ml during the first four weeks) in CA noncarriers for A*03 (2.75; P = 0.018), in CA carriers for Cw*03 (2.99; P = 0.046), and in CA noncarriers for DQA1*04 (2.66; P = 0.018) or DQB1*0402 (2.65; P = 0.018). MHC alleles are associated with the viral decline during the first 28 days of peginterferon therapy.

Distribution of the human leukocyte antigen class II alleles in Brazilian patients with chronic hepatitis C virus infection

Hepatitis C virus (HCV) infection is a global medical problem. The current standard of treatment consists of the combination of peginterferon plus ribavirin. This regimen eradicates HCV in 55% of cases. The immune response to HCV is an important determinant of disease evolution and can be influenced by various host factors. HLA class II may play an important role in immune response against HCV. The objective of the present study was to determine the distribution of HLA class II (DRB1 and DQB1) alleles, their association with chronic HCV infection and their response to interferon therapy. One hundred and two unrelated white Brazilian patients with chronic HCV infection, 52 responders (45 males and 7 females) and 50 non-responders (43 males and 7 females) to antiviral treatment, were included in the study. Healthy Brazilian bone marrow donors of Caucasian origin from the same geographic area constituted the control group (HLA-DRB1, N = 99 and HLA-DQB1, N = 222 individuals). HLA class II genotyping was performed using a low-resolution DRB1, DQB1 sequence-specific primer amplification. There were higher frequencies of HLA-DRB1*13 (26.5 vs 14.1%) and HLA-DQB1*02 (52.9 vs 38.7%) in patients compared with controls; however, these were not significantly different after P correction (Pc = 0.39 and Pc = 0.082, respectively). There was no significant difference between the phenotypic frequencies of HLA-DRB1 (17.3 vs 14.0%) and HLA-DQB1 alleles in responder and non-responder HCV patients. The HLA-DRB1*07 allele was significantly more common in HCV patients (33.3 vs 12.1%) than in controls (Pc = 0.0039), suggesting that the HLA-DRB1*07 allele is associated with chronic HCV infection.

The association between the genetic polymorphism of HLA-DQA1, DQB1, and DRB1 and serum alanine aminotransferase levels in chronic hepatitis C in the Chinese population

BACKGROUND AND AIM

To investigate a possible association between HLA genes with serum alanine aminotransferase (ALT) levels and evaluate whether the HLA-DQA1, DQB1, and DRB1 genes could influence the development of liver damage in chronic hepatitis C.

METHODS

A total of 145 patients with chronic hepatitis C virus (HCV) infection (36 patients with persistently normal ALT values; 109 patients with elevated ALT levels) and 160 uninfected healthy controls were examined for HLA-DQA1, DQB1, and DRB1 molecules by using polymerase chain reaction-sequencing based typing (PCR-SBT).

RESULTS

Among the patients chronically infected with HCV, the frequencies of DQA1*0501, DQB1*0301, and DRB1*0401 alleles were significantly increased in the normal ALT group compared with those with abnormal ALT levels, whereas that of DQB1*0201 was significantly lower. As compared to uninfected healthy controls, DQA1*0501, DQB1*0301, and DRB1*0401 allele frequencies were also statistically higher in the normal ALT group, whereas that of DQB1*0201 was the inverse. The haplotype frequencies of DQA1*0301-DQB1*0301, DQA1*0501-DQB1*0301, and DRB1*1101-DQB1*0301 were found to be significantly higher in the normal ALT group. Multivariate logistic regression indicated that female sex, and the DQB1*0301 allele and DRB1*0401 allele were independently associated with normal ALT values, whereas DQB1*0201 allele was the inverse.

CONCLUSIONS

These results suggest that particular HLA alleles may have an influence on the serum ALT level of chronic HCV infection as a host genetic factor in the Chinese population. The DQA1*0501, DQB1*0301, and DRB1*0401 alleles, and the DQA1*0301-DQB1*0301, DQA1*0501-DQB1*0301, and DRB1*1101-DQB1*0301 haplotypes seem to be associated with low hepatitis activity; whereas DQB1*0201 allele is closely correlated with the progression of liver injury in chronic HCV infection.

Host genetic factors and antiviral immune responses to hepatitis C virus

Human genome variations explain some of the heterogeneity in the immune response to antigenic stimuli. Such differences in response to hepatitis C virus (HCV) antigens can account for the ability of the immune response to clear HCV after an acute infection or to develop more rapidly progressive liver disease. Several studies have examined polymorphisms in several candidate immune-response genes for their relation to these HCV outcomes. Results of some of these studies complement knowledge gained from immunology studies, and others offer new insights into HCV biology. This review summarizes published studies on variation in immune-response genes and HCV outcomes.

Therapy with interferon-alpha and ribavirin for chronic hepatitis C virus infection upregulates membrane HLA-ABC, CD86, and CD28 on peripheral blood mononuclear cells

Multiple interferon-stimulated genes (ISGs) involving T-cell activation are upregulated during initial interferon-alpha-based therapy for chronic hepatitis C virus (HCV) infection. However, the long-term impact on therapeutic outcome in patients remains unknown. In this study, the effects of anti-HCV therapy on the surface expression of HLA-ABC, CD86, and CD28 were longitudinally assessed. These proteins are integral membrane receptors of antigen presentation and triggering of costimulatory signals for activating CD8+ T cells. Peripheral blood mononuclear cells were collected at baseline and post-treatment for 1 day, and 2, 4, 12, and 24 weeks, respectively. This treatment led to a time-related elevation of membrane levels of HLA-ABC and CD86 on B-cells and monocytes in patients with a sustained response (n = 23), but not in those without (n = 8). Meanwhile, upregulation of CD28 on CD4+ and CD8+ T cells was comparable in both groups of sustained responders and non-responders. Steady increases in the B cells' surface and intracellular HLA-ABC were observed, thus, the surface-to-intracellular ratios did not alter over the period of treatment. Furthermore, multivariate analysis shows that increased HLA-ABC on monocytes by week 12 correlates significantly with sustained response (P = 0.033). In conclusion, differential modulation of T-cell activation ISGs, such as HLA-ABC and CD86 might correlate with the outcome of interferon-alpha-based therapy in chronic hepatitis C patients.

Disease progression in chronic hepatitis C: modifiable and nonmodifiable factors

The hepatic complications of chronic hepatitis C (CHC) usually occur only after progression to cirrhosis has taken place. Progression to cirrhosis, however, is extremely variable and depends on a broad set of host and viral factors that modify the rate at which fibrosis develops in a given individual. Despite their inherent limitations, studies of the natural history of CHC have identified several nonmodifiable factors associated with disease progression. These include age at acquisition of infection, sex, and race. More recent reports suggest important roles for host genetic polymorphisms and viral factors. Of greater immediate relevance to patients and their clinicians are the potentially modifiable factors, which include excessive alcohol consumption; smoking (tobacco and marijuana); insulin resistance; and coinfection with hepatitis B virus, human immunodeficiency virus type 1, or schistosomiasis. Unfortunately, to date, there are no reliable predictive models that can accurately estimate the risk of CHC disease progression.

HLA-DPbeta chain may confer the susceptibility to hepatitis C virus-associated hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a heart muscle disease characterized by hypertrophy and diastolic dysfunction of cardiac ventricles. It is suggested that one possible aetiology of HCM is the hepatitis C virus (HCV) infection, but molecular mechanisms underlying development of HCV-associated HCM (HCV-HCM) remains unknown. Because the human leucocyte antigen (HLA) molecule is involved in the control of progression/suppression of viral infection, extensive HLA allelic diversity may modulate the post-infectious course of HCV and pathogenesis of HCV-HCM. Here we undertook a case-control study with 38 patients with HCV-HCM and 132 unrelated healthy controls to reveal the potential impact of polymorphisms in seven classical and two non-classical HLA genes on the pathogenesis of HCV-HCM. It was found that DPB1*0401 and DPB1*0901 were significantly associated with increased risk to HCV-HCM in dominant model (P < 0.028, OR = 3.94, 95% confidence interval (CI) = 1.19, 13.02) and in recessive model (P < 0.007, OR = 9.85, 95% CI = 1.83, 53.04), respectively. The disparity in the gene-dose effect by two susceptible DPB1 alleles may be attributable to the difference between the susceptible (36 A and 55 A) and resistant (8L, 9F, 11G, 57E and 76M) residue-combination consisting of DPbeta anchor pocket for antigenic peptide-binding. These results implied that the HLA-DP molecules with specificity pocket appropriate for HCV antigen(s) might confer the progressive process of HCM among the HCV-infected individuals.

Impact of diabetes mellitus on prognosis of patients infected with hepatitis C virus

Diabetes is a risk factor for the progression of liver fibrosis and development of hepatocellular carcinoma in chronic hepatitis C. However, the impact of diabetes on the long-term prognosis and the synergistic interactions of various host factors for diabetes to the progression of liver fibrosis are unknown. In the present study, we examined the host factors associated with the progression of hepatitis C in 68 patients with a posttransfusion hepatitis (PTH) and analyzed the relationships. Multivariate analysis showed that age of PTH, being male, and type 2 diabetes mellitus were risk factors for the progression of liver fibrosis. By the Kaplan-Meier method, the cirrhosis-free survival rates after the onset of PTH were significantly lower in the diabetic group than in the nondiabetic group (P < .01). Diabetes also had a great impact on the long-term prognosis of chronic hepatitis C by reducing the time from PTH to the occurrence of hepatocellular carcinoma (P < .01) and to liver-related death (P < .05). Coexistence of obesity (body mass index > or =25 kg/m(2)) or hypertriglyceridemia (> or =150 mg/dL) with diabetes had a synergistic effect on liver fibrosis progression in patients with chronic hepatitis C. Thus, the treatment of diabetes, obesity, and hypertriglyceridemia may hold the key to improving the prognosis of chronic hepatitis.

Clearance and persistence of hepatitis C virus in a Tunisian population: association with HLA class I and class II

Human leukocyte antigens (HLAs) of class I and class II are reported to influence the outcome of hepatitis C virus (HCV) infection. The aim of this study was to assess the role of HLA class I and class II in influencing spontaneous viral clearance or persistence in HCV-infected patients. HLA class I (A and B) typing was performed by lymphocytotoxicity test and HLA class II (DRB1) was determined by low-resolution PCR-SSP (polymerase chain reaction amplification with sequence-specific primers) for 99 subjects (48 men and 51 women). Of these, 75 had chronic infection and 24 had viral clearance. No significant differences were observed between individuals with spontaneous viral clearance or chronic HCV infection for age, sex, source of infection, and risk factors. HLAB-w35 and HLA-DRB1*08 occurred more frequently in those with viral clearance (21.7 and 16.6%, respectively) compared with those with chronic infection (5.5 and 2.6%; p < 0.04 and p < 0.01, respectively). DRB1*15 occurred more often in those with chronic infection (29.3%) compared with those with viral clearance (16.66%), but the difference did not reach statistical significance. These results support the hypothesis that specific HLA class I and class II alleles might influence the clearance or persistence of HCV infection. Both Bw35 and DRB1*08 are associated with clearance of circulating HCV whereas DRB1*15 appears to predispose to progression of liver disease in Tunisian patients. Taken together, our results and those previously reported suggest that HLA associations with the outcome of hepatitis C viremia vary in relation to the ethnicity of the population studied. Further prospective studies of larger cohorts of HCV-infected subjects are needed to evaluate, in different populations, the role of specific HLA class I and class II alleles in the outcome of HCV infection.

Long-term follow-up of the hepatitis C HENCORE cohort: response to therapy and occurrence of liver-related complications

The aims of the study were to verify the long-term effect of time on viral clearance in hepatitis C virus (HCV) patients and to find out factors possibly associated with disease progression. A total of 1641 patients recruited from eight European centres in 1996-1997 were re-analysed 5-7 years after inclusion. The occurrence of decompensated cirrhosis, hepatocellular carcinoma (HCC) and liver transplantation was analysed in relation to different host and viral factors. Ninety-three per cent of the HCV patients who had cleared the virus (spontaneously or after antiviral therapy) remained HCV-RNA-negative during follow up and may be considered as 'cured'. Among patients who were sustained responders at inclusion, 2.3% developed liver complications during follow up, and 31% of non-responders did. Advanced age at infection and presence of the human leucocyte antigen (HLA) DRB1*1201-3 allele were possibly associated with a higher rate of progression to decompensated cirrhosis or HCC. Decompensated cirrhosis might be further associated with male gender, non-response to previous therapy, and lack of HLA DRB1*1301 allele, whereas HCC seems to be associated with the presence of the HLA DQ02 allele. Long-term follow up of HCV patients indicates that virological response persists over time and is associated with a very low incidence of liver complications. Advanced age at inclusion, advanced age at infection, viral genotype 1, non-response to previous therapy and possibly some specific HLA alleles are factors independently associated with a faster rate of progression towards liver complications. The large proportion of patients lost to follow up stresses the need for a strengthened and optimized management of HCV patients.