Prevalence and prognostic significance of main metabolic risk factors in primary biliary cholangitis: a retrospective cohort study of 789 patients.

Background: Metabolic risk factors in primary biliary cholangitis (PBC) have not been well described in China. Additionally, it is unclear whether these factors have an impact on the prognosis of PBC patients. Therefore, this study aimed to investigate the prevalence of main metabolic risk factors in PBC, and to evaluate their prognostic values for liver-related outcomes. Methods: A cohort of 789 PBC patients was retrospectively studied between July 2008 and September 2019 by investigating the main metabolic risk factors and analyzing liver-related outcomes. Results: At presentation, 271 (34.3%) patients had concomitant hyperlipidemia, 126 (16.0%) had hypertension, 94 (11.9%) had type 2 diabetes mellitus (T2DM), and 17 (2.2%) had nonalcoholic fatty liver disease (NAFLD). Hyperlipidemia was found to be associated with the lower risk of liver-related death [P<0.0001, hazard ratio (HR): 0.397, 95% confidence interval (CI): 0.268-0.588] and adverse outcomes (P<0.0001, HR: 0.487, 95% CI:0.367-0.646), while hypertension was noted as a risk factor for liver-related death (P=0.001, HR: 1.788, 95% CI:1.268-2.521) and adverse outcomes (P=0.014, HR: 1.417, 95% CI:1.074-1.869). Moreover, age ≥ 55 years old (P=0.005) and cirrhosis (P<0.0001) had superimposition effects on hypertension as a risk factor for liver-related death, while only cirrhosis (P<0.0001) had an effect on hypertension as a risk factor for adverse outcomes. Additionally, anti-sp100 was associated with adverse outcomes (P=0.013) in PBC patients with hypertension in univariate Cox regression analysis. Conclusion: Hyperlipidemia, hypertension, and T2DM were found as main metabolic risk factors in PBC in China. Hyperlipidemia indicated a benign clinical outcome of PBC, while hypertension indicated a poor outcome of PBC. Older age and cirrhosis had superimposition effects on hypertension for liver-related poor outcomes. Anti-sp100 might be associated with adverse outcomes, especially in PBC patients with hypertension.

Disease predisposition of human leukocyte antigen class II genes influences the gut microbiota composition in patients with primary biliary cholangitis.

Background: The human leukocyte antigen (HLA) susceptibility gene is the main genetic risk factor for primary biliary cholangitis (PBC). The prognosis of patients with PBC is linked to gut microbiota dysbiosis. However, whether the HLA alleles are associated with the gut microbiota distribution and disease severity remains unknown. Methods: A cohort of 964 Chinese patients with PBC was enrolled at Beijing YouAn Hospital, Beijing, China. High-resolution genotyping of the HLA class I and class II loci from 151 of these patients was performed using sequence-based PCR. Stool samples were collected from 43 of the 151 fully HLA-typed patients to analyze their microbiota compositions via 16S RNA gene sequencing. Results: Of the 964 patients, the male:female ratio was 114:850, and 342 of these patients (35.5%) had already developed liver cirrhosis (LC) before enrollment. Patients with PBC showed a significantly higher frequency of HLA DRB1*08:03 than did the controls (21.2% vs. 9.0%, P=0.0001). HLA-DRB1*03:01, DRB1*07:01, DRB1*14:05, and DRB1*14:54 frequencies were also increased but did not reach significance after Bonferroni's correction. Conversely, the DQB1*03:01 frequency was significantly lower in patients with PBC than in the controls (24.5% vs. 39.2%, P=0.0010). The patients' gut microbiota were analyzed from four perspectives. The microbial community abundances were significantly lower in FHRAC-positive patients (patients with a combination of five HLA DRB1 high-risk alleles) than in FHRAC-negative patients (P<0.05). Of the top 10 microbial genera, Lachnospiraceae_incertae_sedis was higher in the FHRAC-positive patients than in the FHRAC-negative patients (P<0.05). linear discriminant analysis (LDA) effect-size (LEfSe) analysis showed different microbes at different levels in the FHRAC-negative patients but not in the FHRAC-positive patients. DQB1*03:01-positive patients contained mostly Lactobacillaceae at the family level. A comparison of the FHRAC-positive patients with and without liver cirrhosis showed that the abundances of Veillonella were significantly higher in patients with cirrhosis and FHRAC than in those without cirrhosis and are FHRAC-negative. Conclusion: The HLA class II genes may influence the gut microbiota compositions in patients with PBC. Differential gut microbiota were expressed at different taxonomic levels. Some bacterial abundances may be increased in FHRAC-positive patients with PBC and cirrhosis.

Using two-step cluster analysis to classify inpatients with primary biliary cholangitis based on autoantibodies: A real-world retrospective study of 537 patients in China.

Background: A variety of autoantibodies have been detected in primary biliary cholangitis (PBC), while the presence of autoantibody clusters and their clinical significance have not been fully understood. We aimed at defining autoantibody clusters and to better understand the clinical features and prognosis of PBC patients based on autoantibody clusters under real-world conditions. Methods: We retrospectively analyzed 788 inpatients with PBC evaluated between October 2008 and July 2019, and included 537 patients. Nineteen autoantibodies which were measured routinely were investigated for cluster analysis. Two-step clustering, Kaplan-Meier survival, and Cox regression analyses were used. Results: Five clusters were defined. A cluster of antinuclear antibodies (ANA) and anti-gp210 positive patients were identified with a high rate of cirrhosis at baseline and low survival rate; a cluster of ANA, anti-centromere antibodies (ACA) and/or anti-CENP-B female dominant patients with older disease onset, low level of platelet count at baseline, high rate of hepatic decompensation, and low survival rate was also characterized; and another cluster of anti-mitochondrial antibodies (AMA) and/or AMA-M2, anti-Ro52 and a high rate of anti-gp210 positive patients were identified with a high proportion of male patients and low survival rate. A subgroup of patients with anti-SSA and/or anti-SSB coexists with SjS was also identified; patients with only AMA and/or AMA-M2-positive with a benign clinical outcome and relatively high complication of non-alcoholic fatty liver disease (NAFLD) were also identified. Only anti-gp210 was considered as a significant predictor for poor outcomes especially in patients with cirrhosis. Conclusion: Clustering methods allow the identification of distinct autoantibody profiles of PBC that form clinical subsets and can be useful for personalized approaches to diagnosis, clinical management, and the prediction of clinical outcomes. Anti-gp210 was the strongest predictive factor for poor outcomes especially in PBC patients with cirrhosis under real-world conditions.

Clonal characteristics of paired infiltrating and circulating B lymphocyte repertoire in patients with primary biliary cholangitis.

BACKGROUND: PBC is a prototypical autoimmune liver disease characterized by portal lymphoplasmacyte infiltration. ALD is a prototypical environment-driven disease, featured by mild lymphocyte infiltration. We hypothesize that B cells are more involved in the pathogenesis of PBC. By analysing the infiltrating B cell repertoire, we aimed to unveil greater oligoclonal expansion and active clonal exchange between liver and periphery in PBC than in ALD patients. METHODS: Using NGS of Ig H chain genes, we analysed the liver-infiltrating and paired peripheral B lymphocyte repertoire from nine PBC and four ALD patients. RESULTS: In the liver of PBC and ALD patients, (i) roughly 10% of the B lymphocytes were clonally related and highly expressed, and there were also lineages that underwent extensive clonal expansion; (ii) there was different use of IGHV/IGHJ segments between PBC and ALD, suggesting distinct Ag exposure backgrounds, but this did not lead to a significant difference in their clonal expansion level. Analysis of data sets from paired samples further revealed, (iii) direct clonal exchange and evolutionally related B cell clones between the infiltrating and peripheral repertoire; (iv) the seeding of the infiltrating clones to periphery, and peripheral ones to the liver, for further extensive evolution. CONCLUSIONS: The oligoclonally expanded nature of the infiltrating B cell repertoire implies B cell immunity is involved in the pathogenesis of both diseases. The observed clonal exchange might provide an approach to identify and monitor the infiltrating B cells through the periphery.

Regulation of T cell proliferation by JMJD6 and PDGF-BB during chronic hepatitis B infection.

T cell functional exhaustion during chronic hepatitis B virus (HBV) infection may contribute to the failed viral clearance; however, the underlying molecular mechanisms remain largely unknown. Here we demonstrate that jumonji domain-containing protein 6 (JMJD6) is a potential regulator of T cell proliferation during chronic HBV infection. The expression of JMJD6 was reduced in T lymphocytes in chronic hepatitis B (CHB) patients, and this reduction in JMJD6 expression was associated with impaired T cell proliferation. Moreover, silencing JMJD6 expression in primary human T cells impaired T cell proliferation. We found that JMJD6 promotes T cell proliferation by suppressing the mRNA expression of CDKN3. Furthermore, we have identified platelet derived growth factor-BB (PDGF-BB) as a regulator of JMJD6 expression. PDGF-BB downregulates JMJD6 expression and inhibits the proliferation of human primary T cells. Importantly, the expression levels of JMJD6 and PDGF-BB in lymphocytes from CHB patients were correlated with the degree of liver damage and the outcome of chronic HBV infection treatment. Our results demonstrate that PDGF-BB and JMJD6 regulate T cell function during chronic HBV infection and may provide insights for the treatment strategies for CHB patients.

Human leucocyte antigen alleles and haplotypes and their associations with antinuclear antibodies features in Chinese patients with primary biliary cirrhosis.

BACKGROUND & AIMS: Primary biliary cirrhosis (PBC) is an autoimmune liver disease. Genetic factors are critical in determining susceptibility to PBC. Among human leuocyte antigen (HLA) genes, an association between the DRB1*08 allele and PBC has been reported in many populations, but not in Chinese patients. METHODS: We investigated HLA-A, B, DRB1, and DQB1 alleles and haplotypes in 145 PBC patients and 500 healthy subjects. Patients were also stratified according to autoantibody features, and associations between these and HLA alleles were analyzed. RESULTS: Significant associations existed between HLA-DRB1*08:03 (22.1% vs. 9.0%, Pc < 0.0001, OR = 2.86), DQ2 (41.4% vs. 25.4%, Pc < 0.0001, OR = 2.07) and DQB1*06:01 (31.0% vs. 17.8%, Pc = 0.014, OR = 2.08) alleles and PBC. DRB1*08:03-DQB1*06:01 (22.1% vs. 8.2%, P < 0.0001, OR = 3.17) and DRB1*07:01-DQB1*02:02 haplotypes (28.3% vs. 17.6%, P = 0.005, OR = 1.85) were also associated with PBC susceptibility. In contrast, the DQB1*03:01 allele (21.4% vs. 39.2%, Pc < 0.0001, OR = 0.42) and DRB1*12:02-DQB1*03:01 haplotype (6.9% vs. 14.6%, P = 0.015, OR = 0.43) were significantly decreased in PBC patients compared with controls. DRB1*14:54 and DQ5(1) protected against antinuclear antibody (ANA) (OR = 0.25) and anti-gp210 antibody (OR = 0.39) production, respectively, while HLA-B*44:03 predisposed patients to anti-gp210 antibody (OR = 5.70) production. CONCLUSION: These results suggest that Chinese patients with PBC have a distinct genetic background in eastern Asia, and we confirmed the role of HLA genes in determining PBC susceptibility and autoantibody features in the Chinese population.

Liver transplantation in acute-on-chronic liver failure patients with high model for end-stage liver disease (MELD) scores: a single center experience of 100 consecutive cases.

BACKGROUND: Acute-on-chronic liver failure (ACLF) is a severe clinical condition for which liver transplantation (LT) is the only curative option. However, there are little published data on risk factors and outcomes of LT for ACLF. METHODS: The objective of this study was to analyze preoperative, intraoperative, postoperative, and overall survival data on 100 consecutive cases with ACLF in order to try to determine for which patients LT are futile. RESULTS: One hundred consecutive patients with pathology-confirmed ACLF who underwent LT from June 2004 to September 2012 were enrolled. The preoperative data showed that all patients were in a serious condition with a median high model for end-stage liver disease (MELD) score of 32, total bilirubin of 440.20 umol/L, international normalized ratio (INR) of 3.012, and at least one organ dysfunction as assessed by a Sequential Organ Failure Assessment (SOFA) score of ≥9. The patients had either deceased or a living donor LT with an overall mortality of 20%. The 1-, 3-, and 5-year cumulative survival rates were 76.8%, 75.6%, and 74.1%, respectively, and graft 1-, 3-, and 5-y accumulative survival rates were 73.3%, 72.1%, and 70.6%, respectively. However, the area under receiver operating characteristic of SOFA score, MELD score, as well as Child-Pugh score were 0.552, 0.547, and 0.547, respectively. CONCLUSIONS: Both deceased and living donor LT are effective therapeutic options for patients with ACLF and the short- and long-term survival rates are encouraging. It is important to conduct more prospective and multi-center studies to define preoperatively which patients would benefit from LT.

[The characteristic of T cells response to HBV-specific antigen proteins in patients with HBV infection].

OBJECTIVE: To analyze the characteristic of T cell response to specific antigen proteins in patients with hepatitis B virus infection. METHODS: 76 cases were recruited, including four groups, acute hepatitis B (AHB), active phase of chronic hepatitis B (CHB), inactive HBV carriers (AsC) and past HBV infection. T cell responses stimulated by 3 antigen specific proteins of HBV were detected using enzyme linked immunospot (ELISPOT) assay. RESULTS: (1) There were no significant difference in frequencies to HBsAg, HBcAg and HBeAg in AHB and CHB. The frequencies to HBsAg and HBcAg in AsC were lower than that to HBeAg, and the frequencies to HBsAg in group of past HBV infection were significantly lower than that to HBcAg and HBeAg. (2) The frequencies to HBsAg in AHB and CHB both were higher than in group of past HBV infection. The frequencies to HBcAg of AHB, CHB and AsC were higher than that of group of past HBV infection. (3) There were no significant difference in magnitude to HBsAg, HBcAg and HBeAg in AHB and AsC. In CHB, the magnitude to HBsAg was lower than that to HBcAg. The magnitude of in group of past HBV infection were HBcAg > HBeAg > HBsAg. (4) In four groups, the sequence of the magnitude to HBsAg from high to low was AHB, CHB, group of past HBV infection and AsC. The magnitude to HBcAg in of AsC was lower than other three groups. As to the magnitude to HBeAg, the difference was no significant between any two groups except between AHB and CHB. CONCLUSIONS: The T cell responses in group of AsC to HBeAg were the highest, while the T cell responses to HBcAg were the highest in group of other groups.

[The impact of antiviral therapy on virus-specific T-cell reactivity in patients with chronic hepatitis B].

OBJECTIVE: To investigated the impact of viral load decline on virus-specific T-cell reactivity on patients with chronic hepatitis B. METHODS: 23 cases of patients with chronic hepatitis B were recruited randomized to therapy with nucleoside analogue or alpha interferon from January 2009 to April 2010. Peripheral blood mononuclear cells (PBMCs) were collected longitudinally at baseline and the time of HBV DNA undetected. T-cell reactivity to HBV core antigens were tested using Elispot assays and Luminex. RESULTS: (1) The frequency of T cell reactivity induced by HBcAg in patients with chronic hepatitis B were 91.3% at the time of HBV DNA undetected, which significantly higher than The frequency of 69.6% at baseline. The frequency between nucleoside analogue treatment group and alpha interferon treatment group was no significant difference. (2) The average response magnitude was expressed as spot forming unit (SFU) per million input cells. SFU of T cell responses to HBcAg was 120 SFU/10(6) PBMCs at baseline, much lower than SFU of 1060 SFU/10(6) PBMCs at the time of HBV DNA undetected. No significant difference between patients with negative T cell reactivity at baseline and patients with positive T cell reactivity at baseline was found. In patients with initial virological response (IVR) to therapy and patients with early virological response (EVR), no significant difference was found in the magnitude at baseline as well as at the time of HBV DNA undetected. (3) The average response magnitude of nucleoside analogue treatment group was 1713 SFU/10(6) PBMCs at the time the time of HBV DNA undetected, higher than 189 SFU/10(6) PBMCs at baseline. But in interferon treatment group, the average response magnitude was no significant difference, 120 SFU/10(6) PBMCs at the baseline and 305 SFU/10(6) PBMCs at the time the time of HBV DNA undetected respectively. The average response magnitude in nucleoside analogue treatment group was greater than that in interferon treatment group. (4) As to compare difference of IFN-γ concentration in supernatant of T cell culture solution stimulated by HBcAg, IFN-γ secreted by T cell at the time of HBV DNA undetected was clearly higher than IFN-γ secreted at baseline, (38 ± 9) ng/L and (90 ± 9) ng/L respectively. CONCLUSIONS: Antiviral therapy made profit to improve virus-specific T-cell reactivity in patients with chronic hepatitis B, suggesting the importance to investigate HBV specific T cell responses.

[Clinical characteristics of drug-induced liver injury in 31 pediatric cases].

OBJECTIVE: To investigate the clinical characteristics and responsible agents of drug-induced liver injury (DILI) in pediatric patients. METHODS: Thirty-one cases of DILI treated in our hospital's pediatric ward were retrospectively analyzed. The clinical data for each patient were extracted from the patient's medical records, and included reported causes, physical and biochemical features, natural history, blood examination results, and hepatic pathology findings. RESULTS: The 31 pediatric cases of DILI accounted for 1.7% of the 1831 total cases of drug-induced liver injury treated at our hospital between February 2002 to June 2011. The pediatric DILI population was composed of 20 males and 11 females, with an average age of 8.8+/-3.9 years old (range, 0.3-14.0). The liver injury patterns represented among the cases were: hepatocellular (25.8%), cholestasis (25.8%), and mixed hepatocellular-cholestatic (48.4%). Antimicrobials were the most common cause (41.9%) of DILI, followed by the herbal medicine (29.0%) and febrifuge drugs (19.4%). A single drug was implicated in nine cases (29.0%), and two or more drugs were implicated in 22 cases (71%). Most of the children had good prognosis, but those with pre-existing disease had poor prognosis. One child died of hepatic failure, making the death rate 3.23%. The average hospitalization time was 25.2 days, and the patients with hepatocellular injury had shorter hospitalization time than those with mixed injury. CONCLUSION: Drug-induced liver injury in our pediatric population was most often caused by antimicrobials, followed by herbal medicine and febrifuge drugs. Most patients presented with mixed hepatocellular-cholestatic injury. Children with pre-existing diseases or hepatic failure had poor prognosis.

Downregulation of the AU-rich RNA-binding protein ZFP36 in chronic HBV patients: implications for anti-inflammatory therapy.

Inflammation caused by chronic hepatitis B virus (HBV) infection is associated with the development of cirrhosis and hepatocellular carcinoma; however, the mechanisms by which HBV infection induces inflammation and inflammatory cytokine production remain largely unknown. We analyzed the gene expression patterns of lymphocytes from chronic HBV-infected patients and found that the expression of ZFP36, an AU-rich element (ARE)-binding protein, was dramatically reduced in CD4(+) and CD8(+) T lymphocytes from chronic HBV patients. ZFP36 expression was also reduced in CD14(+) monocytes and in total PBMCs from chronic HBV patients. To investigate the functional consequences of reduced ZFP36 expression, we knocked down ZFP36 in PBMCs from healthy donors using siRNA. siRNA-mediated silencing of ZFP36 resulted in dramatically increased expression of multiple inflammatory cytokines, most of which were also increased in the plasma of chronic HBV patients. Furthermore, we found that IL-8 and RANTES induced ZFP36 downregulation, and this effect was mediated through protein kinase C. Importantly, we found that HBsAg stimulated PBMCs to express IL-8 and RANTES, resulting in decreased ZFP36 expression. Our results suggest that an inflammatory feedback loop involving HBsAg, ZFP36, and inflammatory cytokines may play a critical role in the pathogenesis of chronic HBV and further indicate that ZFP36 may be an important target for anti-inflammatory therapy during chronic HBV infection.

Identification of T cell epitopes on soluble liver antigen in Chinese patients with auto-immune hepatitis.

AIM: To identify soluble liver antigen (SLA)-specific dominant epitopes and analyse the correlation between SLA-specific T cell response and the status of the disease. METHODS: A cross-sectional analysis of SLA-specific T cell responses to 54 overlapping peptides covering the entire SLA sequence was performed using an interferon (IFN)-γ ELISpot assay in 31 patients with auto-immune hepatitis (AIH)-1, 15 patients with primary biliary cirrhosis, 16 hepatitis B virus, seven hepatitis C virus infection and 10 healthy subjects, in order to assess the correlation between SLA-specific T cell responses and the clinical outcome. RESULTS: Soluble liver antigen-specific IFN-γ responses in AIH were significantly more frequent in AIH patients (58.1%) than those in controls (6.7% in PBC, P=0.001; 4.3% in hepatitis B/C, P<0.001 and 0% in healthy subjects, P=0.0015). Among 31 AIH patients, the frequency of recognition and the magnitude of response to SLA peptides in anti-SLA antibody-positive patients were higher and stronger than those negative for anti-SLA antibodies (P=0.02 and 0.037 respectively). We further analysed T-cell restriction and found that six individual SLA peptides (4, 9, 11, 12, 41 and 44) were recognized by CD4 T cells, and the most frequently recognized peptides were peptides 12 (61.1% of participants), followed by peptide 4 and peptide 44 (55.6 and 38.9% respectively). Moreover, a positive association was found between the breadth of recognition of SLA peptides and the indices of liver damage. CONCLUSION: T cell response to SLA in Chinese patients with AIH is broad and associated with hepatocyte damage.

Prognostic factors and survival analysis of antimitochondrial antibody-positive primary biliary cirrhosis in Chinese patients.

BACKGROUND AND AIMS: Primary biliary cirrhosis (PBC) is a relatively uncommon liver disease, and information on the prognosis and survival of PBC patients in mainland China is lacking. We therefore conducted a retrospective study to investigate the prognostic factors and survival in Chinese PBC patients. METHODS: Between October 2001 and May 2009, patients registered at Beijing You'an Hospital with abnormal liver function and serum positivity for antimitochondrial antibody (AMA) and/or AMA-M2 (n = 391) were screened. Patients diagnosed with PBC were identified, and their medical data were reviewed and analyzed for mortality predictors. RESULTS: A total of 147 PBC patients were identified (mean age: 54 years, range: 28-81), of whom 126 (85.7%) were women. At the time of diagnosis, 119 patients (81.0%) were symptomatic, 28(19.0%) had hepatic decompensation, and no patients were asymptomatic. During a median follow-up period of 48 months (range: 2-312), 36 patients (24.5%) died or underwent liver transplantation, and 65 patients (44.2%) developed hepatic decompensation. The overall 5-year survival rate was 79%. Multivariate analysis indicated that Mayo risk score ≥6.11(P = 0.008), and serum IgG ≥ 17.20 g/l (P = 0.016) were associated with mortality. CONCLUSIONS: Most Chinese PBC patients in this study were symptomatic at diagnosis and had significant mortality. Mayo risk score, and serum IgG were independent prognostic factors for survival.

[Clinical significance of liver function and autoantibodies in patients with acute or chronic drug-induced liver injury].

OBJECTIVE: To investigate the clinical significance of liver function and autoantibodies in patients with acute or chronic drug-induced liver injury. METHODS: 51 patients with drug-induced liver injury were divided into acute drug induced liver injury group and chronic drug induced liver injury group, liver function and autoantibodies were compared between these two groups. RESULTS: There was no significant difference (P more than 0.05) in alanine aminotransferase [(412.1+/-387.5) U/L and (376.0+/-319.7) U/L], aspartate aminotransferase [(352.5+/-457.9) U/L and (198.8+/-142.7) U/L], total bilirubin [(109.7+/-104.80)micromol/L and(102.4+/-135.7)micromol/L], direct bilirubin [(66.4+/-73.3)micromol/L and (61.2+/-72.1)micromol/L], alkaline phosphatase [(133.4+/-50.1) U/L and (147.4+/-97.3) U/L], gamma-glutamyltransferase [(139.9+/-134.1) U/L and (180.6+/-227.9) U/L], and albumin [(41.3+/-4.9) g/L and (39.8+/-5.3)g/L] between these two groups, however, the level of globulin [(25.1+/-5.3) g/L and (28.6+/-5.1) g/L] was significantly different between these two groups (P less than 0.05). The titers of Anti-nuclear antibody (ANA) and smooth muscle antibody (SMA) were less than or equal to 1:320 in patients with acute drug induced liver injury. The titers of ANA, antimitochondrial antibody (AMA), and SMA were more than or equal to 1:320 in most of the patients with chronic drug induced liver injury. CONCLUSION: Liver function has no value in the diagnosis of acute or chronic drug induced liver injury. High titer autoantibodies are found in patients with chronic drug induced liver injury.

[Detection of antigen-epitope-specific cytotoxic T lymphocytes in patients with hepatitis B virus infection by enzyme linked immunospot assay].

OBJECTIVE: To investigate the ability of secreting interferon-gamma (IFN-gamma) of the peripheral blood monocular cells (PBMC) stimulated by hepatitis B virus (HBV)-specific cytotoxic T lymphocyte (CTL) epitopes peptides and to analyze the difference of CTL immune response in patients with HBV infection. METHODS: Four HLA-A2-restricted HBV cytotoxic T lymphocyte epitopes [Tp: HBV polymerase 575-583 (FLLSLGIHL), Te1: envelope 28-39 (IPQSLDSWWTSL), Te2: envelope 183-191 (FLLTRILTI) and Tc: core 18-27 (FLPSDFFPSV)] were synthesized. Human leucocyte antigen (HLA)-A2 typing was detected by Flow cytometry. PBMCs which were isolated from patients with chronic hepatitis B(CHB), patients with chronic severe hepatitis B(CSH), subjects with past HBV infection(N1) and healthy blood donors (N2) were stimulated by the four HLA-A2-restricted HBV CTLs epitopes. Enzyme linked immunospot (ELISPOT) assay was used to detect the frequency of secreting IFN-gamma CTL in each group. RESULTS: (1) HLA-A2 typing: 20 of 44 patients with CHB (45.5%) were HLA-A2 positive, 10/18 (55.6%) in CSH and 6/10 (60%) in group N1 were HLA-A2 positive.10 healthy blood donors' HLA-typing was detected in the early study.(2) ELISPOT results: (1) The total responses to the four epitopes in CHB, CSH, N1 and N2 groups were 50% (10/20), 10% (1/10), 83.3% (5/6) and 10% (1/10), respectively. The response in N1 group was significantly higher than that in CSH group (chi(2) = 9.000, P = 0.008) and N2 group (chi(2) = 9.000, P = 0.008). (2) The CTL average magnitude response to Tp epitope, Te1 epitope, Te2 epitope and Tc epitope was also significantly higher in past HBV infection group (77 SFC/10(6) PBMC, 59 SFC/10(6) PBMC, 100 SFC/10(6) PBMC and 57 SFC/10(6) PBMC, respectively) than that of CSH group (10 SFC/10(6) PBMC, 0 SFC/10(6) PBMC, 0 SFC/10(6) PBMC and 20 SFC/10(6) PBMC respectively, all P < 0.01) and N2 group (15 SFC/10(6) PBMC, 0 SFC/10(6) PBMC, 22 SFC/10(6) PBMC and 30 SFC/10(6) PBMC respectively, all P < 0.01). CONCLUSION: This study indicates that the T cell immune response to HBV-specific epitopes might be detected either in patient with chronic HBV infection or with previous HBV infection. This response should be much higher in patients with past HBV infection, even the virus had been cleared for long time. These results demonstrate that HBV-specific CTL might play an important role in the clearance of the virus.