CSH guidelines for the diagnosis and treatment of drug-induced liver injury.

Drug-induced liver injury (DILI) is an important clinical problem, which has received more attention in recent decades. It can be induced by small chemical molecules, biological agents, traditional Chinese medicines (TCM), natural medicines (NM), health products (HP), and dietary supplements (DS). Idiosyncratic DILI is far more common than intrinsic DILI clinically and can be classified into hepatocellular injury, cholestatic injury, hepatocellular-cholestatic mixed injury, and vascular injury based on the types of injured target cells. The CSH guidelines summarized the epidemiology, pathogenesis, pathology, and clinical manifestation and gives 16 evidence-based recommendations on diagnosis, differential diagnosis, treatment, and prevention of DILI.

High serum IL-21 levels after 12 weeks of antiviral therapy predict HBeAg seroconversion in chronic hepatitis B.

BACKGROUND & AIMS: Interleukin-21 (IL-21) stimulates T cell and B cell responses and plays a role in control of chronic viral infections. The role of IL-21 in chronic hepatitis B virus (HBV) infection is not understood. METHODS: Serum IL-21 levels were measured by enzyme immunoassay in 75 HBeAg-positive chronic hepatitis B (CHB) patients undergoing telbivudine treatment. The findings were validated in 103 patients from a separate clinical trial of telbivudine. A complete response to telbivudine was defined as having both HBeAg seroconversion and serum HBV-DNA level <300 copies/ml by treatment week 52. The proportions of T-cells producing IL-21 and/or expressing programmed death 1 (PD-1) in peripheral blood mononuclear cells were assessed longitudinally during treatment by intracellular cytokine staining and flow cytometry. RESULTS: Median serum IL-21 levels at treatment week 12 were significantly higher in patients who did achieve vs. patients who did not achieve a complete response in both the initial (128.4 vs. 69.2 pg/ml, p=0.003) and the validation (142.2 vs. 89.9 pg/ml, p=0.004) trials. Serum levels of IL-21 (p=0.005) or HBV-DNA (p=0.003) levels at treatment week 12 independently predicted HBeAg seroconversion in the first year of treatment. The decrease in PD-1 expression on CD4(+) and CD8(+) T cells during the first 12 weeks on telbivudine treatment was not correlated with changes in IL-21 concentrations. CONCLUSIONS: Serum IL-21 levels may be a biomarker for HBeAg seroconversion, and may contribute to individualization of antiviral therapy in HBeAg-positive CHB. IL-21 may also have a role in immunotherapy for CHB.

Complementarity-determining region 3 size spectratypes of T cell receptor beta chains in CD8+ T cells following antiviral treatment of chronic hepatitis B.

An increased CD8(+) T cell response to hepatitis B virus (HBV) peptides occurs between 12 and 24 weeks after starting antiviral therapy for chronic hepatitis B. It is not known whether these cells have antiviral function. The aim of this study was to determine whether clonal expansions of CD8(+) T cells at these time points predict the virological response to therapy. Peripheral blood CD8(+) T cells were obtained from 20 patients treated with lamivudine or telbivudine for chronic hepatitis B at baseline, 12 weeks, and 24 weeks. The CDR3 spectratype of each T cell receptor (TCR) ß chain variable region (Vß) gene family was analyzed, and the changes in the numbers of Vß families with clonal expansions were compared in subjects with (n = 12) and without (n = 8) a virological response (52 week HBV DNA < 300 copies/ml). The number of CD8(+) TCR Vß families with clonal expansions at 12 weeks relative to baseline (median [10th to 90th percentile], +2.5 [0 to +7] versus +1 [0 to +2], P = 0.03) and at 24 weeks relative to 12 weeks (+1 [0 to +2] versus -1 [-3 to +4], P = 0.006) was higher in subjects with a virological response versus subjects without a virological response, as were interleukin-2 (IL-2) but not IL-21 mRNA levels in peripheral blood mononuclear cells. The duration of new expansions at 12 weeks was higher (P < 0.0001) in responders. Increased numbers of CD8(+) T cell expansions after antiviral therapy are associated with a virological response to treatment. These CD8(+) T cells are a potential target for a therapeutic vaccine for chronic hepatitis B.

[C gene-targeting short hairpin RNA suppresses the replication and expression of hepatitis B virus in BHK-21 cells].

OBJECTIVE: The vaccines currently developed against infectious diseases fail to induce effective antiviral immune responses to control an abrupt outbreak of viral diseases epidemic in a short space of time. Hence there is an urgent need to develop emergency vaccines capable of producing prophylactic effects against infectious diseases. RNA interference (RNAi) is a mechanism that inhibits gene expression by causing the degradation of specific RNA molecules or hindering the transcription of specific genes. The rapidity and uniqueness of RNAi responses can make up for the current inadequacy of antiviral preventive regimes. Here we evaluate the antiviral potential of short hairpin RNA (shRNA) targeting C (core) gene of hepatitis B virus (HBV). It plays essential roles in HBcAg encoding and viral attachment to susceptible cells during its life cycle. The present study was intended to investigate the inhibitory effect of C-specific shRNAs on HBV replication and expression in BHK-21 cells. METHODS: The reporter gene expression vector of pC-EGFP-N1 was constructed by cloning the DNA (PCR product) of HBV C into the EcoRI-HindIII sites of pEGFP-N1 to fuse C to enhanced green fluorescent protein (EGFP) for providing a reporting system for monitoring siRNA function. Plasmid pC was constructed by cloning the DNA of HBV C into the EcoRI-HindIII sites of pCDNA3.1B(-) directly under the control of cytomegalovirus promoter. Two plasmids (S1 & S2) were constructed to express shRNAs targeting C of HBV with the length of 24 nucleotide (nt) homologous in sequence to the HBV C gene. Plasmids were designed and synthesized according to the HBV genome (HBV genotype B, ayw1 subtype) of chronic hepatic B patients from 56 ethnic minorities in China. After cloning and sequencing, the investigators registered them with the GenBank accession numbers of AY517488 (CYN/2002) and AY517489 (CYN/2000), etc. Simultaneously, one of nonspecific shRNA-S3 with a length of 24 nt was also designed randomly for negative control. After cloning into vector pU6 for constructing shRNA-expressing plasmids, they were then cotransfected into BHK-21 cells along with reporter gene expression vector of pC-EGFP-N1. First, upon a determination of the number of cells exhibiting EGFP expression in BHK-21 cells as detected by an Olympus BH-2 fluorescence microscope and FACS-440 flow cytometry (Becton-Dickinson, USA) at different times after cotransfection, the investigators evaluated the gene inhibitory efficiency of both plasmids by an EGFP reporter system in BHK-21 cells. Subsequently, the antiviral efficacy of both plasmids in BHK-21 cells was further investigated by real-time quantitative polymerase chain reaction. RESULTS: In comparison with single plasmid transfection pC-EGFP-N1 or pEGFP-N1, fluorescence microscope and flow cytometry detection at 24 h post-cotransfection revealed that the expression of reporter gene EGFP in cotransfection group involving S1 or S2 and S1 + S2 cotransfection group was reduced significantly by about 90% in EGFP signal versus the control. And the EGFP expression in control plasmid cotransfected S3 or pU6 was not significantly reduced in BHK-21 cells (P < 0.01). It was found that the expression of mRNAs of HBV C and EGFP gene as detected by real-time quantitative PCR was the same as that detected by fluorescence microscope and flow cytometry (P < 0.01), thereby further corroborating the antiviral efficacy of RNAi. The antiviral efficacy extended to almost 48 hours. The results indicted that a DNA vector-based RNAi technology could effectively and specifically inhibit the replication and expression of HBV in BHK-21 cells. CONCLUSION: For the first time it has been found that RNAi induced by shRNA targeting C gene exerts an effective and unique inhibition of HBV replication and expression in BHK-21 cells. Thus RNAi may provide an effective emergency vaccine against major infectious diseases such as HBV infection.

[Characteristics of CDR3 of TCR beta on CD8+ T cells in chronic hepatitis B patients].

OBJECTIVE: To analyze the characteristics of CDR3 of TCRbeta on CD8+ T cells in chronic hepatitis B patients. METHODS: Eight patients with chronic hepatitis B (ALT more than 2 ULN) were enrolled in this study. CD8+ T cells were isolated from peripheral blood. RT-PCR was proformed to amplify the CDR3 of TCRbeta, and the PCR products were sequenced and analyzed. RESULTS: The chronic hepatitis B patients showed obvious clonal expansion of T cell, and three perturbation patterns of T cell expansion were showed in the CDR3 of TCRbeta, including monoclonicity, oligoclonicity and skewed peak patterns. The number of perturbation families of CD8+ subpopulation was significantly higher than that of CD8- subpopulation (10.6+/-4.7 vs. 4.1+/-3.1, t = 6.619, P less than 0.01). In 3 out of 8 patients, the number of perturbation families of CD8+ subpopulation was also higher than that of PBMCs without depleting CD8+ subpopulation. CONCLUSIONS: The characteristics of CDR3 of TCRbeta may help to understand the inflammatory response in CHB patients.

[Changes of serum HBsAg in HBeAg positive chronic hepatitis patients with sustained viral response to long-term lamivudine treatment].

OBJECTIVE: HBsAg loss is rare in chronic hepatitis B patients, even in the patients with long-term nucleos(t)ide analogue therapy; therefore information about serum HBsAg kinetics will be of value in understanding this unusual occurrence. METHODS: Forty-five consecutive patients were studied, which were all HBeAg positive and never had antiviral therapy prior to lamivudine treatment; they then achieved rapid and good viral responses (defined as undetectable HBV DNA [Roche Lightcycler, less than 1000 copies/ml] at treatment week 24 and they remained so until week 156). Abbott Architect HBsAg assay was used to quantify serum HBsAg and HBV genotypes were determined by direct sequencing. RESULTS: Twenty-six (57.8%) patients had HBeAg loss during the observation and one patient had HBsAg loss following his HBeAg seroconversion. Serum HBsAg levels decreased to 39.5% (median) of their baseline values at week 12, but no further significant reductions of serum HBsAg were found afterwards. Changes of serum HBsAg were comparable between patients with or without HBeAg loss. Serum HBsAg levels at their baselines were higher in HBV genotype B (HBV/B, n = 21) patients than in genotype C (HBV/C, n = 24) patients. HBV/B patients achieved many more HBsAg reductions than HBV/C ones (75.5 vs. 26.0%, median, P less than 0.05) in the first 12 treatment weeks, however HBsAg levels at week 156 were comparable between these two subgroups. HBsAg changes mainly showed two distinct patterns: a biphasic pattern (HBsAg levels were less than 60% of baseline ones at week 12 and 24, n = 25) and a maintaining pattern (HBsAg levels were greater than 80% of the baseline ones at week 12 and 24, n = 14). Logistic regression analysis showed that low serum HBsAg at baseline (odds ratio 0.020, 95% confidence interval 0.002-0.743, P less than 0.05) and HBV/C infection (odds ratio 8.206, 95% confidence interval 1.070-62.948, P less than 0.05) were the determinants of the occurrences of the maintaining pattern. CONCLUSION: In patients we examined, their HBsAg changes were mainly presented as either a biphasic pattern or a maintaining pattern, which were associated with HBV genotypes (B/C) but not with HBeAg loss. This might explain that why HBsAg loss is a rare occurrence even with long-term lamivudine therapy.

[Characteristics of HBcAg(18-27) CTL epitopes of the main epidemic HBV strains in China].

OBJECTIVE: To study the characteristics of the virology background of HLA-A2 restricted HBcAg(18-27) epitope mutations in HBV infected patients in China. METHOD: 30 HBV sequences with different genotypes from Genbank were analyzed by bioinformatics and the mismatched primers were designed for constructing a PCR-RFLP method to screen HBcAg(18-27)V/I in China. The distributions of HBcAg(18-27)V/I of 160 samples with HBV genotype B/C infection from 8 areas in China were screened and analyzed by PCR-RFLP and sequencing. The affinity of HBcAg(18-27)V/I to HLA-A0201 was analyzed through referencing the bioinformatics websites. RESULTS: We successfully constructed a PCR-RFLP method for screening HBcAg(18-27)V/I from genotype B/C, and only 3 samples with HBcAg(18-27)V sequence were found in the 160 samples (3/160, 1.88%). The affinity of HBcAg(18-27)I to HLA-A 0201 was lower than the one of HBcAg(18-27)V through bioinformatic analysis (HLA ligand score was 123 vs 156, and the SYFPEITHI score was 22 vs 24). CONCLUSION: The last amino acid of most HBcAg(18-27) sequences of epidemic HBV strains in China is isoleucine, and not valine. Therefore HBcAg(18-27) sequence background in different HBV genotypes should be thoroughly considered when using it as a reference or control in immunological research about HBV.

[Kinetics of HBV mutants conferring adefovir resistance (rtn236t) and a method to detect them rapidly].

OBJECTIVE: The aim was to build a PCR-RFLP method for detecting rtN236T mutants and to observe their kinetics in chronic hepatitis B (CHB) patients. METHODS: Seven CHB patients who had suboptimal viral response or viral breakthrough under adefovir mono-therapy were studied. Part of the HBV reverse transcriptional gene from serial sera samples was sequenced with PCR products or cloned HBV DNA; mutations at rt236 were simultaneously analyzed by a PCR-RFLP assay. Genetic diversity of HBV was observed by calculating Hamming distance within domains B, C and D of RT. RESULTS: Three patients had viral breakthrough and one with suboptimal viral response had adefovir-resistance mutants, one had rtA181V mutation and three had rtN236T mutation. A novel PCR-RFLP assay based on restriction enzyme HpaI or DraI for on the detection of rtN236T mutant was established, which detected 10% minor strains with 100% specificity. Mutants (rtA181V or rtN236T) appeared 0-8 months earlier than the viral breakthrough, then afterwards became the dominant ones. In one patient after stopping the adefovir therapy, 3 months later a wild type virus re-took again the mutant one (rtN236T); in one patient who developed a rt236T mutant after 132 weeks of adefovir treatment, a novel mutant (rtN236V) appeared and then became the dominant one while adefovir treatment continued. CONCLUSIONS: A rapid and easy method was established to detect rtN236T mutants. Mutants for adefovir-resistance accumulated rapidly then became dominant, but they could be taken over again by a wild type or novel mutant HBV.

[Distribution of hepatitis B virus genotype B subgenotype in China].

OBJECTIVE: To investigate the distribution of hepatitis B virus (HBV) genotype B subgenotype in China. METHODS: A cohort of 511 patients with chronic HBV genotype B infection, collected from 7 centers across China, were analyzed by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or nucleotide sequencing. RESULTS: For the 511 patients, only subgenotype Ba was identified and subgenotype Bj was not found. CONCLUSION: In China, subgenotype Ba was the most prevalent HBV strains, while subgenotype Bj was very rarely found.

[Affects of HBV genotypes (B/C) on the levels of serum and intrahepatic HBsAg].

OBJECTIVE: To observe the effects of HBV genotypes on the level of HBsAg in serum and hepatocytes in chronic hepatitis B patients without antiviral therapy. METHODS: Seventy-six chronic hepatitis B inpatients were enrolled into this study, and liver biopsies and histologic diagnosis were performed, and serum samples were collected at the time point of liver biopsy. PCR-RFLP method was adopted to determine the genotype of hepatitis B virus and Abbott Architect HBsAg assay was used to quantify the serum HBsAg. Immunostaining for antigens in liver tissues with monoclonal antibody (for HBsAg) or polyclonal antibodies (for HBcAg) was carried out in consecutive slides. The percentages of hepatocytes for HBsAg stain, hepatocytes for HBcAg nuclear stain and hepatocytes for HBcAg cytoplasm stain were estimated in the ranges of 0 (negative), < or = 1%, 1+; 2% - 5%, 2+; 6% - 25%, 3+; 26% - 50%, 4+; and > 50%, 5+. The distributions of positive cells in slides are described as single or isolated, cluster or widespread. Surface gene was directly sequenced with the serum HBV DNA from 6 patients with genotype B and 8 with genotype C HBV infection, respectively. RESULTS: Four HBV genotypes were detected in 76 patients: 47 patients with B, 21 with C, 3 with D and 5 were infected by genotype B mixed with C HBV infection. Age, gender, serum HBV DNA level, ALT, AST or histological evaluation (grades and stages scores) were not different between the patients infected with genotype B or C HBV. The level of serum HBsAg was not significantly different between the patients infected with genotype B or C HBV, but the proportions of hepatocytes stained with HBsAg was greater in patients with C type HBV infection than B (P < 0.01). In the liver slides from the patients infected HBV genotype B, HBsAg was stained frequently in single or isolated hepatocytes (22/47), and widespread HBsAg-positive hepatocytes were often seen in the patients with C type HBV (8/21), P < 0.01. In the patients with B type HBV, serum HBsAg was positively correlated with serum HBV DNA (r = 0.674, P = 0.000), proportion of hepatocytes with HBcAg in nucleus (r = 0.534, P = 0.000) and in cytoplasm (r = 0.405, P = 0.004). In the patients with C type HBV infection, serum HBsAg had positive correlation only with serum HBV DNA (r = 0.503, P = 0.017). Proportion of HBsAg positive hepatocytes was positively correlated only with the proportion of HBcAg cytoplasm positive hepatocytes in the patients with B type HBV (r = 0.318, P = 0.029) and no correlation with serum HBsAg, HBV DNA, or proportions of hepatocytes with HBcAg in nucleus. Analysis of the first 40 amino acid sequences of surface antigen showed that variations most existed at amino acid 3, 4, 5 and 8. CONCLUSION: Proportion of HBsAg in hepatocytes is significantly greater in the patients with C type HBV than those with B type HBV. Positive correlation between serum HBsAg and viral replication was seems to be more significant in the patients with HBV genotype B infection.

Analysis of the CDR3 length of TCR alphabeta T cells in the peripheral blood of patients with chronic hepatitis B.

To clarify the characteristics of TCR alphabeta T cells in the peripheral blood of patients with chronic hepatitis B (CHB), we investigated the patterns of Complementarity Determining Region3 (CDR3) length distribution for all 24 TCR BV gene families and 32 TCR AV gene family in the peripheral blood lymphocytes of two patients with CHB and two healthy controls by immunoscope spectratyping technique. We found that the profiles of CDR3 length distribution for all TCR AV and TCR BV family showed Gaussian distribution (the polyclonal TCR alphabeta T cells) in healthy controls, however, the restricted usage of TCR BV and TCR AV family (the oligoclonal TCR alphabeta T cells) has been monitored in two CHB patients, furthermore, the oligoclonal TCR alphabeta T cells showed the different CDR3 sequences and length, it might be correlated to the different epitope of hepatitis B virus (HBV) or the different HLA type of the patients. Detailed analysis of the CDR3 length of TCR alphabeta T cells might be interesting to light on the further study of the individualized immunotherapy of CHB and the further research of the new T lymphocyte epitope vaccine of HBV.

[Analysis of T cell receptor BV dominant usage and CDR3 sequences during acute exacerbation in patients with chronic hepatitis B].

OBJECTIVES: To understand the role cellular immunology plays in the pathogenesis of chronic hepatitis B (CHB) through analysis of T cell receptor (TCR) beta chain variable region gene (BV) family dominant usage and beta chain complementarity determining region3 (CDR3) sequences of peripheral blood mononuclear cells of the patients. METHODS: TCR BV families were amplified by inverse polymerase chain reaction (RT-PCR), and the dominant usage of BV families and CDR3 repertoire were analyzed by immunoscope technology for 8 CHB patients during their acute exacerbations and for 4 healthy blood donors who served as controls. The clonality of the T cells suspected by immunoscope was further confirmed by CDR3 sequencing. RESULTS: The TCR BV CDR3 repertoire of the 4 healthy blood donors showed a Gaussian distribution. In the 8 CHB patients, however, the clonal expansion of T cells showed different TCR BV families with each patient. The T cells of the clonal expansion shared different CDR3 sequences. CONCLUSION: The peripheral blood T cells of CHB patients during their acute exacerbation showed significantly a clonal expansion and their T cell clonal expansion may be stimulated by several HBV epitopes. These results indicate that cellular immunology is involved in the pathogenesis of the liver inflammation process of CHB.

[Establishment and application of real-time fluoriescene-based metry polymerase chain reaction for hepatitis B virus genotyping].

OBJECTIVE: To explore a new method for determining hepatitis B virus (HBV) genotypes B-D with real-time fluorescence-based PCR. METHODS: The PCR primers and probes were designed according to the analysis of 143 complete HBV genomes from GenBank and on the basis of a search for genotype-specific nucleotide sequences which were conserved in the 3 HBV genotypes. Real-time fluorescence-based PCR was performed for HBV genotyping of 128 samples collected from Lanzhou. Three samples of each genotype of B, C and D were randomly selected and their S gene was sequenced for confirmation of the results of PCR-based method. RESULTS: Real-time PCR identified genotype B in 26 (20.3%), genotype C in 92 (71.9%), and genotype D in 10 (7.8%) cases. The sequencing results of the S gene of 18 PCR-produced clones were in complete consistence with those of fluorescence-based PCR. CONCLUSION: The real-time PCR method is convenient, highly sensitive, rapid and accurate, especially suitable in clinical and large-scale epidemiological studies.