Hepatitis B virus quasispecies in hepatic and extrahepatic viral reservoirs in liver transplant recipients on prophylactic therapy

Abstract

The characterization of hepatitis B virus (HBV) quasispecies in different compartments in liver transplant (LT) recipients may be helpful in optimizing prophylaxis regimens. The aims of this study were to evaluate liver, peripheral blood mononuclear cells (PBMC), and plasma samples for HBV and to compare the quasispecies in hepatic and extrahepatic sites in LT recipients on long-term prophylaxis. For 12 patients followed for up to 15 years post-LT, liver, plasma, and PBMC samples [all HBV DNA-negative according to conventional polymerase chain reaction (PCR) assays] were evaluated for HBV DNA by a sensitive nested PCR method [covalently closed circular DNA (cccDNA) for liver and PBMC samples] and by the sequencing and phylogenetic analysis of polymerase quasispecies. For the 10 patients on prophylaxis with no clinical recurrence (median time post-LT ¼ 15.5 months, range ¼ 12-96 months), liver samples were HBV DNA-reactive in 9 of 10 cases, plasma samples were HBV DNA-reactive in 3 of 10 cases, and PBMC samples were HBV DNA-reactive in 2 of 7 cases (including 1 case with HBV cccDNA in PBMCs). The sequence analysis showed that all HBV clones had a wild-type (WT) sequence in the liver and PBMCs. In 2 patients with early HBV recurrence post-LT who were treated with nucleosides only, HBV DNA was detected in serum, PBMC, and liver samples, and HBV cccDNA was found in liver samples. An HBV lamivudine-resistant variant with an M204I mutation was identified in liver (70% and 18% of the clones) and plasma samples (100% of the clones), but a WT sequence was found in 70% and 100% of the PBMC clones. In conclusion, despite prophylaxis and the absence of HBV DNA in serum according to conventional assays, HBV is detectable in the serum, liver, and PBMCs of almost all patients, and this supports the use of continued anti-HBV therapy in this group. Antiviral drugresistant variants are more frequent in the liver versus PBMCs, but both compartments are potential sources of reinfection. Liver Transpl 17:955-962,

The detection of (total and ccc) HBV DNA in liver transplant recipients with hepatitis B vaccine against HBV reinfection

“…8 Although there were only a few cases of HBV recurrence after 5 years, low-level HBV DNA was detected in 45.4% of patients who did not experience HBV recurrence during 10 y of follow-up. 11 HBV total and ccc DNA were detectable in the sera, livers, and PBMCs of almost all patients for up to 15 y post-LT. 10 Moreover, Lenci et al found that most patients with undetectable HBV DNA at transplant who received conventional HBV prophylaxis had no evidence of intrahepatic HBV total or ccc DNA; in that study, only one patient experienced HBV recurrence after transplant and tested positive for intrahepatic HBV total and ccc DNA. 9 All patients with HBV reactivation were found to have HBV total and ccc DNA in liver allografts and/or PBMCs.…”

“…9 All patients with HBV reactivation were found to have HBV total and ccc DNA in liver allografts and/or PBMCs. [8][9][10] Recipients with detectable HBV ccc DNA might be considered at high risk of HBV recurrence after liver transplantation. In our study, over one fifth of recipients were found to have HBV DNA in the liver or PBMCs even though they received antiviral agents and HBIG for many years after LT, and this finding was consistent with that of previous studies.…”

“…However, it is very difficult to completely eradicate intrahepatic and extrahepatic HBV DNA and ccc DNA in liver transplant recipients, which are potential sources of reinfection. [8][9][10][11] Active immunization with standard hepatitis B vaccines in these patients is considered a promising substitute to the current treatment strategy, although the results of this new strategy have been controversial. [12][13][14][15][16][17][18][19][20][21][22] Some studies have reported that responders to hepatitis B vaccination, defined as patients with anti-HBs, should stop taking HBIG and/or antiviral agents.…”

Okült Hepati̇t B Vi̇rus Enfeksi̇yonu: Moleküler Mekani̇zmalar Ve Kli̇ni̇k Önemi̇

“…Okült B'li karaciğer ve/ya organ alıcılarında OBİ'li donörden organ nakli sonrası, alıcının yeni karaciğer dokusunda alıcı veya donöre ya da her ikisine ait HBV sekanslarını içeren (ek olarak HBV cccDNA) OBİ varlığı tespit edilebilmekte (64), fakat bu durumun nakil sonrası dönemde HCV pozitif hastalarda progresyon artışına neden olabildiğine dair kısmi verilerin dışında klinik önemi henüz bilinmemektedir. Ayrıca Hepatit B immünglobulin ve lamivudin tedavisi alan nakil sonrası dönemde HBsAg'si negatifleşen HBsAg pozitif organ alıcılarında da OBİ gelişebildiği rapor edilmektedir (64,65). (66)(67)(68).…”

Withdrawal of posttransplant hepatitis B virus prophylaxis: A blind test

“…These results are in contrast with the results of other studies in which the majority of HBsAg negative LT recipients receiving longterm HBV prophylaxis have total HBV DNA or cccDNA detectable in liver and/or peripheral blood mononuclear cells (PBMCs) supporting the rationale for an indefinite post-LT HBV prophylaxis. (12)(13)(14) We reported that 20 out of 44 (45%) HBsAg negative patients 10 years after LT receiving longterm HBIG 6 antiviral have persistence of HBV DNA in the serum (18/20), PBMC (13/20), or liver (10/20). (12) The differences between these results could be explained by differences in patient selection: HBV DNA levels at transplant, rate of HBeAg positivity at transplant, presence of HCC, duration of follow-up, type of HBV prophylaxis, frequency of antibody to hepatitis B core-related antigen (HBc) positive grafts, monocentric versus multicentric studies, sampling variability, and the sensitivity and specificity of the molecular techniques used in quantifying total and cccDNA.…”