PLoS One. 2015 Jun 26;10(6):e0130209. doi: 10.1371/journal.pone.0130209.
Total Hepatitis B Core Antigen Antibody, a Quantitative Non-Invasive Marker of Hepatitis B Virus Induced Liver Disease.
Yuan Q1, Song LW1, Cavallone D2, Moriconi F2, Cherubini B2, Colombatto P2, Oliveri F2, Coco BA2, Ricco G2, Bonino F3, Shih JW1, Xia NS1, Brunetto MR2.
Author information
1State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Institute of Diagnostics and Vaccine Development in Infectious Diseases, School of Public Health, Xiamen University, Xiamen, China.
2Laboratory of Molecular Genetics and Pathology of Hepatitis Viruses, Hepatology Unit, Reference Center of the Tuscany Region for Chronic Liver Disease and Cancer, University Hospital of Pisa, Pisa, Italy.
3Digestive and Liver Disease, General Medicine II Unit, University Hospital of Pisa, Pisa, Italy.
Abstract
Non invasive immunologic markers of virus-induced liver disease are unmet needs. We tested the clinical significance of quantitative total and IgM-anti-HBc in well characterized chronic-HBsAg-carriers. Sera (212) were obtained from 111 HBsAg-carriers followed-up for 52 months (28-216) during different phases of chronic-HBV-genotype-D-infection: 10 HBeAg-positive, 25 inactive-carriers (HBV-DNA≤2000IU/ml, ALT<30U/L), 66 HBeAg-negative-CHB-patients and 10 with HDV-super-infection. In 35 patients treated with Peg-IFN±nucleos(t)ide-analogues (NUCs) sera were obtained at baseline, end-of-therapy and week-24-off-therapy and in 22 treated with NUCs (for 60 months, 42-134m) at baseline and end-of-follow-up. HBsAg and IgM-anti-HBc were measured by Architect-assays (Abbott, USA); total-anti-HBc by double-antigen-sandwich-immune-assay (Wantai, China); HBV-DNA by COBAS-TaqMan (Roche, Germany). Total-anti-HBc were detectable in all sera with lower levels in HBsAg-carriers without CHB (immune-tolerant, inactive and HDV-superinfected, median 3.26, range 2.26-4.49 Log10 IU/ml) versus untreated-CHB (median 4.68, range 2.76-5.54 Log10 IU/ml), p<0.0001. IgM-anti-HBc positive using the chronic-hepatitis-cut-off" (0.130-S/CO) were positive in 102 of 212 sera (48.1%). Overall total-anti-HBc and IgM-anti-HBc correlated significantly (p<0.001, r=0.417). Total-anti-HBc declined significantly in CHB patients with response to Peg-IFN (p<0.001) and in NUC-treated patients (p<0.001); the lowest levels (median 2.68, range 2.12-3.08 Log10 IU/ml) were found in long-term responders who cleared HBsAg subsequently. During spontaneous and therapy-induced fluctuations of CHB (remissions and reactivations) total- and IgM-anti-HBc correlated with ALT (p<0.001, r=0.351 and p=0.008, r=0.185 respectively). Total-anti-HBc qualifies as a useful marker of HBV-induced-liver-disease that might help to discriminate major phases of chronic HBV infection and to predict sustained response to antivirals.
The dynamic quantification range of the new total-anti-HBc assay allows to distinguish chronic-HBV-infection associated with HBV-induced liver disease, namely chronic-hepatitis-B (CHB), from chronic HBV infection without HBV-induced liver damage, namely non-inflammatory HBeAg-positive and inactive HBeAg-negative phases, independently from HBV-genotypes. Our validation study confirms in well characterized HBsAg-carriers infected with genotype-D- HBV the results obtained in Asian patients infected with genotype B and C [21]; the highest levels of total-anti-HBc were detected in CHB, both HBeAg-positive and HBeAg-negative and the lowest levels in inactive-carriers (Fig 1). Very low levels of the antibody were reported in the non-inflammatory, HBeAg-positive immune-tolerant-phase in genotype-B and-C infections [21–23]. Consistently in our HBeAg-positive-carriers total-anti-HBc levels comparable to those of inactive-carriers were found only in an immune-tolerant carrier, whereas the remaining CHB-patients showed high antibody levels. Total-anti-HBc declined during antiviral and correlated with response to Peg-IFN±NUC at EOT in both REL and SVR and at EOF in SVR during NUC treatment (Figs 1 and 3). In SVR-patients total-anti-HBc levels declined reaching at EOF values comparable to inactive-carriers. Interestingly in NUC-treated patients, the lower total-anti-HBc serum levels corresponded to the longer follow-up in disease remission. Antibody levels were significantly lower in NUC-treated patients) tested about 60 months after starting therapy as compared with patients with Peg-IFN SVR tested 24-weeks after EOT (p = 0.002). The distribution pattern of IgM-anti-HBc in the same subgroups mimics that of total-anti-HBc, but unfortunately the dynamic quantification range of the IgM-assay hampers the diagnostic accuracy since half of values fall below the analytical specificity cut-off of the assay. Comparing the kinetics of the different HBV-markers according to response to Peg-IFN we found (Fig 3) that the decline of total-anti-HBc during therapy parallels that of HBV-DNA and this may be useful in clinical practice to confirm the effectiveness of Peg-IFN antiviral activity. However, during Peg-IFN-treatment total-anti-HBc is unable to distinguish REL from SVR who are instead identified better by HBsAg-kinetics as reported previously [17–20]. During NUC therapy the kinetics of total anti-HBc differ from those of the other HBV markers and the total-anti-HBc decline provides an added value to HBV-DNA and HBsAg monitoring beckoning the remission of HBV-induced liver damage under effective antiviral therapy. In patients treated with Entecavir or Tenofovir viral load is consistently suppressed in the very early phase of treatment, whereas HBsAg declines very slowly over time [17–20]. Interestingly long-term NUC-treated patients with very low levels of total-anti-HBc experienced the HBsAg-clearance with anti-HBs-sero-conversion during follow-up. Thus, quantification of total-anti-HBc might help to predict HBsAg loss and future long-term prospective studies should address the issue in larger cohort of patients. Finally, the findings that total-anti-HBc kinetics correlate with ALT levels as well as IgM-anti-HBc in both naturally-occurring [25–27] and therapy-induced remission and reactivation phases [26,27] support the view that total-anti-HBc is a reliable marker of HBV-induced liver disease in chronic HBsAg-carriers. In chronic HBeAg positive hepatitis B baseline total-anti-HBc levels were shown to predict HBeAg to anti-HBe seroconversion in Asiatic HBeAg-positive-CHB patients, treated with Peg-IFN or NUC infected with HBV genotype B and C [24]. Our findings underline the potential of the assay also in the management of chronic HBeAg-negative-CHB of the Mediterranean Area infected with HBV genotype D. In addition our work suggests that quantification of total-anti-HBc may be helpful to distinguish the inactive HBsAg carrier from HBeAg-negative-CHB which is characterized by intervening phases of disease remission and reactivation [25–26], to identify patients with higher chance of HBsAg clearance and to provide a new tool to answer the unmet needs for treatment tailoring [27–30].
All available data support the view that q-anti-HBc is complementary to HBsAg quantification. HBsAg is a product of HBV replication, ccc-HBV-DNA transcription and viral mRNAs translation whereas total-anti-HBc is expression of the antiviral immune response against the HBV “core” antigen. Our data suggest that symmetry or asymmetry of the two markers may have important diagnostic implications: high levels of HBsAg associated with low levels of total-anti-HBc are diagnostic for the immune-tolerance or florid non-inflammatory phase of HBeAg-positive HBV-infection, while high levels of both markers identify chronic hepatitis B (either HBeAg-positive and HBeAg-negative). In cirrhotic patients with advanced HBeAg-negative-CHB total-anti-HBc levels are high because of persistent HBV-induced liver disease whereas HBsAg may decline because of HBsAg deletion mutants which hamper HBsAg secretion. In treated patients the decline of total-anti-HBc parallel HBsAg-kinetics in patients who respond to anti-viral treatment (sustained responders to therapy), but is asymmetric with the unchanged HBsAg levels in patients whose hepatitis B recurs after treatment discontinuation (Relaspers). In addition the decline of HBsAg during antiviral therapy is HBV genotype dependent whereas the decline of total-anti-HBc is HBV genotype independent. Thus the combined used of both markers can improve the management of the HBsAg carrier consistently.
In conclusion total-anti-HBc as measured by double-antigen-sandwich-immune-assay is a reliable non invasive marker of HBV-induced liver disease helpful to identify chronic-HBV-infection associated with HBV-induced liver disease. Larger prospective studies are needed address to address its significance particularly in the clinical management of NUC-treated patients.作者: StephenW 时间: 2015-6-29 16:33