Management of hepatitis B virus reactivation in patients with hematological malignancies treated with chemotherapy

Change in Hepatitis B Surface Antibody Titers After Chemotherapy in Patients With Hematological Malignancies

Background The change in hepatitis B surface antibody (anti-HBs) titers after chemotherapy (CT) in patients with hematological malignancy, affecting factors, and its clinical implications have not been sufficiently understood. Therefore, we aim to evaluate the change in anti-HBs titers and hepatitis B virus reactivation (HBVr) after CT. Methods This retrospective study enrolled patients with hematological malignancies who received CT between 2013 and 2021. All patients were followed up for HBVr and a change in anti-HBs titers for one year. Results Overall, 192 patients were included. In total, 33.9% of the patients were anti-HBs (+) and 26% of the patients were anti-HBc (+) ± anti-HBs (+). Hepatitis B virus (HBV) prophylaxis was given to 35 (70%) of 50 Anti-HBc (+) patients. Tenofovir disoproxil fumarate and entecavir prophylaxis were initiated in 25 (71.4%) and 10 (28.6%) patients, respectively. A significant decrease was found in anti-HBs titers of all patients (p=0.017). A significant decrease was also found in anti-HBs titers of HBc IgG (+) patients and those who received four or more courses of CT (p=0.025; p=0.041). HBVr was not diagnosed in any of the patients. Conclusion Chemotherapeutic agents administered for hematological malignancy have serious immunosuppression effects. In these patients, anti-HBs titers may decrease or become negative one year after CT. Anti-HBs titer before CT or its change after CT may not constitute a risk for HBVr patients who received HBV prophylaxis in line with current guidelines and these recommendations.

HBsAg (-)/HBsAb (-)/HBeAg (-)/HBeAb (+)/HBcAb (+) predicts a high risk of hepatitis B reactivation in patients with B-cell lymphoma receiving rituximab based immunochemotherapy

Patterns of hepatitis B virus reactivation (HBV-R) in HBsAg (-)/HBcAb (+) patients with B-cell non-Hodgkin lymphoma (NHL) receiving rituximab based immunochemotherapy have not been well described. The retrospective study included 222 HBsAg (-)/HBcAb (+) NHL patients as training cohort and 127 cases as validation cohort. The incidence of HBV-R in HBsAg (-)/HBcAb (+) B-cell NHL patients was 6.3% (14/222), of which that in HBsAg (-)/HBsAb (-)/HBeAg (-)/HBeAb (+)/HBcAb (+) population was 23.7% (9/38). Multivariate analysis showed that HBsAg (-)/HBsAb (-)/HBeAg (-)/HBeAb (+)/HBcAb (+) correlated with a high risk of HBV-R in B-cell lymphoma patients (training phase hazard ratio [HR], 10.123; 95% confidence interval [CI], 3.389-30.239; p < 0.001; validation phase HR, 18.619; 95% CI, 1.684-205.906; p = 0.017; combined HR, 12.264; 95% CI, 4.529-33.207; p < 0.001). In the training cohort, the mortality rate of HBsAg (-)/HBcAb (+) B-cell NHL caused by HBV-R was 14.3% (2/14) while that for HBV reactivated HBsAg (-)/HBsAb (-)/HBeAg (-)/HBeAb (+)/HBcAb (+) population was up to 44.4% (4/9). As a high incidence of HBV-R and high mortality after HBV-R was found in HBsAg (-)/HBsAb (-)/HBcAb (+)/HBeAg (-)/HBeAb (+) patients with B-cell NHL receiving rituximab based immunochemotherapy, prophylactic antiviral therapy is recommended for these patients.

Comparison of Tenofovir Disoproxil Fumarate and Entecavir in the Prophylaxis of HBV Reactivation

INTRODUCTION

Current guidelines recommend starting antiviral prophylaxis to prevent hepatitis B virus (HBV) reactivation in patients receiving immunosuppressive treatments (IST). The aim of this study was to compare the efficacy of entecavir (ETV) and tenofovir disoproxil fumarate (TDF) for prophylaxis.

METHODS

Patients, who were HBsAg and/or anti-HBc IgG positive and scheduled to receive IST for oncologic and hematologic diseases, were enrolled into the study. Those who were already receiving an antiviral treatment for HBV or had an associated HIV, hepatitis C, D were excluded. The remaining patients with a prophylaxis indication according to the AGA guideline were randomized to receive either ETV (0.5 mg/day) or TDF (245 mg/day). Prophylaxis was continued for 6-12 months after completion of IST. Patients were followed up for 1 year after completion of prophylaxis. The HBV reactivation rates and side effects of the drugs were compared.

RESULTS

The study group included 120 patients. There was no significant difference between the demographic data, viral serologic parameters and reactivation risk profiles of the ETV (n = 60) and TDF (n = 60) groups. Forty-one patients in the ETV and 36 in the TDF group completed the antiviral prophylaxis, and no HBV reactivation was observed. HBV reactivation was observed in 4 of 37 patients (10.8%) in the ETV group and 5 of 35 (14.3%) patients in the TDF group (including one with flare) during the follow-up after completion of prophylaxis. Ten patients in the ETV group (16.7%) and 14 patients (23.3%) in the TDF group experienced side effects (p = 0.77). One patient in the TDF group had to switch to ETV due to severe itchy, maculopapular rash-like lesions.

CONCLUSIONS

ETV and TDF had a similar efficacy in the prophylaxis of HBV reactivation in patients undergoing IST, with none of the patients experiencing reactivation.

Prevalence of occult HBV infection in Western countries

Due to a lack of standardized tests, it is difficult to obtain prevalence data and define the real impact of occult HBV infection (OBI) in Western countries. The present review article addresses the prevalence of OBI, defined as presence of hepatitis B virus (HBV) DNA in liver tissue or plasma in HBsAg-negative subjects, in Western countries. This varies in different studies according to the different methodologies used (based on serology vs virology), to the sample analyzed for the diagnosis (liver tissue vs plasma), to the different populations studied, to the different geographical variations in the HBV spread, to the host characteristics (age, gender, risk factors for acquiring HBV infection) and to the presence of other parenteral infections (hepatitis C virus and/or human immunodeficiency virus [HIV] infections). Considering the different liver diseases analyzed, that is in patients with cryptogenic cirrhosis or advanced liver fibrosis, the prevalence of OBI ranges 4% to 38%. Considering the different populations studied, in the case of parenteral blood exposure it is about 45%, in patients with chronic hepatitis C it is estimated at about 52%, in HIV-infected patients it ranges from 0% to 45%, in blood donors from 0% to 22.7% and in hemodialysis patients it ranges from 0% to 54%. In conclusion, OBI is a virological entity to be considered when performing the patient's evaluation for immunosuppressive diseases, liver pathologies, or for blood transfusions. Knowing the prevalence and clinical impact of OBI will allow better patient management.

Role of hepatitis B antibody in predicting reactivation of resolved hepatitis B virus infection in leukemia patients

BACKGROUND & AIMS

Quantification of anti-HBs and anti-HBc predicts the risk of HBV reactivation (HBVr) in lymphoma patients receiving rituximab treatment. However, it remains unclear whether the quantification is predictive of HBVr in leukemia patients undergoing immunosuppression.

METHODS

and patients: Clinical and laboratory data of the leukemia patients with resolved HBV infection diagnosed between January 2013 and March 2018 were retrospectively collected. Data series of HBV seromarkers and HBV DNA levels before the patients receiving chemotherapy and/or hematopoietic stem cell transplantation (HSCT) and during follow-up duration were analyzed.

RESULTS

In total, 533 leukemia patients with resolved HBV infection were included. The incidences of HBVr were 5.7% (25/441) and 2.2% (2/92) in patients receiving HSCT and chemotherapy, respectively. In patients receiving HSCT, acute lymphoid leukemia had a significantly higher incidence of HBVr than acute myeloid leukemia (8.9% vs 3.9%, P < 0.05). The incidence varied almost zero to 40% due to the differences in the profiles of HBV antibodies. High anti-HBs (cut-off of 79.2 IU/L) or low anti-HBc levels (cut-off of 4.475, S/CO) at baseline were associated with a low risk of HBVr. Anti-HBe status did not affect the incidence of HBVr. However, the cut-offs were only predictive of HBVr in the patients who had negative anti-HBe.

CONCLUSION

The baseline profiles of HBV antibodies are predictive of the risk of HBVr in leukemia patients undergoing immunosuppression. However, seronegative anti-HBe is a prerequisite for using baseline anti-HBs and anti-HBc quantification to predict HBVr risk.

HBV flare associated with immunosuppressive treatments: it is still dangerous in the third-generation antivirals era

BACKGROUND

There are limited data about the mortality and morbidity of patients with HBV flare related to immunosuppressive treatments (IST) in the third-generation antivirals era. Herein, we performed a multi-centric study in patients treated with entecavir (ETV) or tenofovir disoproxil fumarate (TDF) and evaluated their clinical course.

METHODS

The study group included patients who were referred to gastroenterology or infectious disease specialists at eight different hospitals in Turkey. HBV flare was defined as at least a threefold elevation in alanine aminotransferase (ALT) levels above the upper limit of normal range. The demographic data, IST protocol, virological markers, liver tests, international normalized ratio (INR), HBV DNA, reactivation risk profile according to AGA guideline, MELD and MELD-Na scores were retrospectively evaluated. The primary aim of the study was to determine the liver-related mortality, including transplantation, at 12 weeks and factors predicting it. Secondary aims were to compare ETV and TDF with respect to mortality and time to ALT, bilirubin normalization and HBV DNA undetectability.

RESULTS

The study group included 40 patients (29 males, mean age: 57 ±12 years). Twenty-five patients (62.5%) had a high risk of reactivation. Twenty-six patients received TDF and 14 patients received ETV treatment. Eight (20%) patients developed acute liver failure and one patient (2.5%) underwent living donor liver transplantation. Seven patients died due to liver-related complications, revealing a mortality rate of 17.5%. In multivariate analysis, total bilirubin levels at the onset, ALT levels and delta-MELD score at the first week were the independent risk factors for liver related mortality (HR: 1.222, 1.003, 1.253 and 95% CI: 1.096, 1.362; 1.001, 1.004 and 1.065, 1.470, respectively). There was no significant difference between the TDF and ETV groups with respect to time to normalize ALT and bilirubin levels, HBV DNA undetectability and mortality rates (16% and 21.4%, respectively).

CONCLUSIONS

HBV flare associated with IST has a high mortality in the third-generation antivirals era. High total bilirubin at the onset and high ALT and delta-MELD score at the first week predict poor prognosis.

Reactivation of hepatitis B virus infection in patients with hemo-lymphoproliferative diseases, and its prevention

Reactivation of hepatitis B virus (HBV) replication is characterized by increased HBV-DNA serum values of about 1 log or by HBV DNA turning positive if previously undetectable in serum, possibly associated with liver damage and seldom life-threatening. Due to HBV reactivation, hepatitis B surface antigen (HBsAg)-negative/anti-HBc-positive subjects may revert to HBsAg-positive. In patients with hemo-lymphoproliferative disease, the frequency of HBV reactivation depends on the type of lymphoproliferative disorder, the individual's HBV serological status and the potency and duration of immunosuppression. In particular, it occurs in 10%-50% of the HBsAg-positive and in 2%-25% of the HBsAg- negative/anti-HBc-positive, the highest incidences being registered in patients receiving rituximab-based therapy. HBV reactivation can be prevented by accurate screening of patients at risk and by a pharmacological prophylaxis with anti-HBV nucleo(t)sides starting 2-3 wk before the beginning of immunosuppressive treatment and covering the entire period of administration of immunosuppressive drugs and a long subsequent period, the duration of which depends substantially on the degree of immunodepression achieved. Patients with significant HBV replication before immunosuppressive therapy should receive anti-HBV nucleo(t)sides as a long-term (may be life-long) treatment. This review article is mainly directed to doctors engaged every day in the treatment of patients with onco-lymphoproliferative diseases, so that they can broaden their knowledge on HBV infection and on its reactivation induced by the drugs with high immunosuppressive potential that they use in the care of their patients.

Management of HBV reactivation in non-oncological patients

INTRODUCTION

HBV reactivation (HBVr) in patients undergoing immunosuppressive therapy is a well-known event. While there are clear directives on the management of current or resolved HBV infection in onco-hematological diseases, there are few data regarding patients with non-oncological diseases. Thus, the aim of the present review is to evaluate HBVr in patients with non-oncological diseases, and identify the management of these patients to prevent HBVr. Areas covered: Original papers, case reports and meta-analyses reporting data on HBVr of current or resolved infection in gastrointestinal, dermatological, rheumatologic and neurological diseases were evaluated. Expert commentary: In HBsAg-positive subjects, those with HBV-related hepatitis (both HBeAg-positive or negative) should be treated with a high genetic barrier nucleos(t)ide analog. The patients with HBV-infection (both HBeAg-positive and negative) an antiviral prophylaxis should be used, with lamivudine in those HBeAg-negative without signs of advanced liver disease, and with ETV, TDF or TAF in all the HBeAg-positive or in those HBeAg-negative with signs of advanced liver disease. In HBsAg-negative/anti-HBc positive subjects, when the risk of HBV reactivation is moderate (use of B-cell depleting agents), a prophylaxis-strategy may be considered; instead, in those with low risk of HBVr, a pre-emptive therapy strategy may be used.

Pharmacotherapy-Induced Hepatitis B Reactivation Among Patients With Prior Functional Cure: A Systematic Review

OBJECTIVE

To describe and quantify the incidence and morbidity of hepatitis B reactivation (HBVr) secondary to pharmaceutical agents (eg, rituximab, tumor necrosis factor inhibitors, direct-acting antivirals [DAAs] for hepatitis C) among patients with previously resolved hepatitis B infection.

DATA SOURCES

The MEDLINE database was searched from inception through July 2018 using the terms hepatitis B + ( reactivation OR [drug or drug class linked to HBVr]).

STUDY SELECTION AND DATA EXTRACTION

Relevant English-language cohort studies or randomized trials quantifying the incidence of HBVr secondary to pharmacotherapy among patients negative for hepatitis B surface antigen and DNA and positive for hepatitis B core antibody were included.

DATA SYNTHESIS

Among 2045 articles, 102 met inclusion criteria. Receipt of rituximab was associated with the highest risk of HBVr (for oncological indication: 6.2% rate [225/3601 patients]) and subsequent hepatitis (up to 52.4% of all HBVr cases). Biologic agents for autoimmune disease were uncommonly associated with HBVr (2.4%, 56/2338), with only 4 cases of hepatitis, all attributable to rituximab. Reactivation caused by DAAs was rare (0.3%, 28/8398), with no cases of hepatitis. Relevance to Patient Care/Clinical Practice: This review compares and contrasts the incidence and clinical relevance of HBVr for various pharmacotherapies among patients with functionally cured hepatitis B, with discussion of appropriate risk mitigation strategies.

CONCLUSIONS

Among patients with prior functional cure of hepatitis B, prophylactic antiviral therapy is recommended with rituximab administration irrespective of indication because of a high risk for HBVr-associated morbidity. Enhanced monitoring alone is reasonable for patients receiving nonrituximab biologics or DAAs.

Hepatitis B virus reactivation in HBsAg-negative, anti-HBc-positive patients receiving immunosuppressive therapy: a systematic review

Background:

The optimal management of HBsAg-negative, anti-HBc-positive patients who receive immunosuppression remains unclarified. We systematically reviewed the available data on potential predictors of the risk of hepatitis B virus (HBV) reactivation in such patients.

Methods:

A literature search identified 55 studies with 3640 HBsAg-negative, anti-HBc-positive patients who received immunosuppressive regimens.

Results:

HBV reactivation was reported in 236 (6.5%) patients. The pooled HBV reactivation rates did not differ between patients with detectable or undetectable HBV DNA in studies with hematological diseases or regimens containing rituximab, but it was higher in patients with detectable than in those with undetectable HBV DNA who were taking rituximab-free regimens (14% vs. 2.6%; risk ratio [RR] 12.67, 95% CI: 95%CI 2.39-67.04, P=0.003) or had non-hematological diseases, although the latter was not confirmed by sensitivity analysis (RR 8.80, 95%CI 0.71-109.00, P=0.09). The pooled HBV reactivation rates were lower in patients with positive than in those with negative anti-HBs in studies with hematological (7.1% vs. 21.8%; RR 0.29, 95%CI 0.19-0.46, P<0.001) or non-hematological (2.5% vs. 10.7%; RR 0.28, 95%CI 0.11-0.76, P=0.012) diseases, and rituximab-containing (6.6% vs. 19.8%; RR 0.32, 95%CI 0.15-0.69, P=0.003) or rituximab-free (3.3% vs. 9.2%; RR 0.36, 95%CI 0.14-0.96, P=0.042) regimens.

Conclusions:

The risk of HBV reactivation is high; therefore, anti-HBV prophylaxis should be recommended in HBsAg-negative, anti-HBc-positive patients with hematological diseases and/or rituximab-containing regimens, regardless of HBV DNA and anti-HBs status. In contrast, patients with non-hematological diseases or rituximab-free regimens have a low risk of HBV reactivation and may not require anti-HBV prophylaxis if they have undetectable HBV DNA and positive anti-HBs.

Eighteen-month lamivudine prophylaxis on preventing occult hepatitis B virus infection reactivation in patients with haematological malignancies receiving immunosuppression therapy

This study evaluated the long-term efficacy and safety of an 18-month lamivudine prophylaxis in 68 HBsAg-negative/anti-HBc-positive patients with oncohaematological disease. All 68 consecutive HBsAg-negative/anti-HBc-positive patients with an oncohaematological disease and naïve for chemotherapy observed from April 2008 to December 2012 at 2 Hematology Units in Naples were treated with lamivudine for 18 months after stopping chemotherapy and monitored for HBsAg at months 1 and 3 during chemotherapy and then every 3 months after its discontinuation. During follow-up, 13 (19.1%) of the 68 patients died of complications related to their oncohaematological disease, and 3 (4%) showed a virological HBV reactivation (retroconversion to HBsAg positivity) 1-7 months after the discontinuation of lamivudine prophylaxis (2 treated for chronic lymphocytic leukaemia and one for Waldenstrom's disease); of these, 2 showed a biochemical reactivation. Comparing the demographic and clinical characteristics of the 3 patients with a virological HBV reactivation to the 65 without, the former were older (median age and range: 67 years [75-78] vs. 61 [24-88]; P = .05) and were less frequently treated for B-cell non-Hodgkin lymphoma (B-NHL) (0 vs. 70.7%, P = .03). In conclusion, a 18 months of lamivudine prophylaxis was effective in preventing HBV reactivation in HBsAg-negative/anti-HBc-positive patients treated for B-NHL. However, in patients with chronic and severe immunodepression, such as those with chronic lymphocytic leukaemia and Waldenstrom's disease, prophylaxis should be continued for an indefinite period.

Randomized prospective study evaluating tenofovir disoproxil fumarate prophylaxis against hepatitis B virus reactivation in anti-HBc-positive patients with rituximab-based regimens to treat hematologic malignancies: The Preblin study

BACKGROUND

Hepatitis B virus (HBV) reactivation in patients with resolved HBV infection (HBsAg negative, antiHBc positive) is uncommon, but potentially fatal. The role of HBV prophylaxis in this setting is uncertain. The aim of this study was to compare the efficacy of tenofovir disoproxil fumarate (TDF) prophylaxis versus close monitoring in antiHBc-positive, HBsAg-negative patients under treatment with rituximab (RTX)-based regimens for hematologic malignancy.

METHODS

PREBLIN is a phase IV, randomized, prospective, open-label, multicenter, parallel-group trial conducted in 17 hospitals throughout Spain. Anti-HBc-positive, HBsAg-negative patients with undetectable HBV DNA were randomized to receive TDF 300 mg once daily (Group I) or observation (Group II). The primary endpoint was the percentage of patients showing HBV reactivation during 18 months following initiation of RTX treatment. Patients with detectable HBV DNA (Group III) received the same dose of TDF and were analyzed together with Group I to investigate TDF safety.

RESULTS

Sixty-one patients were enrolled in the study, 33 in the TDF treatment group and 28 in the observation group. By ITT analysis, HBV reactivation was 0% (0/33) in the study group and 10.7% (3/28) in the observation group (p = 0.091). None of the patients in either group showed significant differences in liver function parameters between baseline and the last follow-up sample. TDF was generally well tolerated and there were no severe treatment-related adverse events.

CONCLUSION

In patients with hematological malignancy and resolved hepatitis B infection receiving RTX-based regimens, HBV reactivation did not occur in patients given TDF prophylaxis.

Role of surface antibody in hepatitis B reactivation in patients with resolved infection and hematologic malignancy: A meta-analysis

Patients with resolved hepatitis B virus (HBV) infection who are treated for hematological malignancies remain at risk for HBV reactivation. Because of conflicting studies about whether the antibody to hepatitis B surface antigen (anti-HBs) protects against reactivation in patients with resolved infection (hepatitis B surface antigen negative) receiving chemotherapy for hematological malignancies, we conducted a meta-analysis to determine if anti-HBs reduces HBV reactivation risk. We sought English-language studies through March 1, 2016, in Medline and other sources that examined reactivation in patients with resolved HBV infection receiving chemotherapy for hematologic malignancies. The absolute risks and odds ratio (OR) of reactivation with versus without anti-HBs were estimated in random-effects model meta-analyses. In 20 studies involving 1,672 patients not receiving antiviral prophylaxis, the reactivation risk was 14% (95% confidence interval [CI] 9.4%-19%) in 388 patients who had antibodies to hepatitis B core antigen only versus 5.0% (95% CI 3.0%-7.0%) in 1,284 patients who also had anti-HBs. Anti-HBs reduced reactivation risk with a pooled OR of 0.21 (95% CI 0.14-0.32) versus patients with antibody to hepatitis B core antigen only. Similar results were found when limiting the analysis to rituximab chemotherapy (OR = 0.19, 95% CI 0.11-0.32) and lymphoma (OR = 0.18, 95% CI 0.11-0.28).

CONCLUSION

In patients with resolved HBV receiving chemotherapy for hematological malignancies without antiviral prophylaxis, anti-HBs positivity is associated with a decreased risk of reactivation; HBV screening in this patient population should include the routine use of anti-HBs, and those who are anti-HBs-negative should receive antiviral prophylaxis. Future studies should examine the effect of anti-HBs serum titers, the potential role for booster vaccinations, and antiviral prophylaxis prior to chemotherapy in this patient population. (Hepatology 2017;66:379-388).

The Impact of Chemotherapy on Hepatitis B Antibody Titer in Patients with Hematological Malignancies

Objective:

To investigate the influence of chemotherapy (CT) on HBsAb titer in patients receiving CT due to hematological malignancy.

Materials and Methods:

The data of 75 patients who received CT with the diagnosis of various hematological malignancies and who had serum HBsAb levels measured prior to and after the cessation of CT were evaluated retrospectively.

Results:

The median age of the patients was 52 years (range: 16-78) with 49 (65%) males and 26 (35%) females. Median HBsAb titer decreased significantly after CT compared to the pre-CT median HBsAb titer [68 (range: 0-1000) vs. 100 (range: 6.2-1000)] (p=0.001). In subgroup analysis, median HBsAb titer decreased significantly after CT in acute leukemia patients [110 (range: 6.2-1000) vs. 67.8 (range: 0-1000)] (p=0.003) and in patients receiving intensive CT [97.2 (range: 6.2-1000) vs. 71 (range: 0-1000)] (p=0.036). The decrease in median HBsAb titer was significant in male patients (p<0.001). HBsAb became negative after CT in 9 patients who were HBcAb-negative and had lower pre-CT HBsAb levels.

Conclusion:

HBsAb decreased after CT, especially in acute leukemia and male patients, and in patients receiving intensive CT.

PREVALENCE OF OCCULT HEPATITIS B INFECTION IN IRANIAN CANCER PATIENTS BEFORE CHEMOTHERAPY TREATMENT

BACKGROUND

Occult hepatitis B infection is characterized by negative hepatitis B surface antigen (HBsAg) and also detectable hepatitis B virus (HBV) -DNA, with or without hepatitis B core antibody (anti-HBc). HBV reactivation in individuals under immunosuppressive therapy is critical, occurring in occult HBV.

OBJECTIVE

In this study, we aimed to determine the prevalence of occult HBV infection among hepatitis B surface antigen negative in cancer patients before receiving chemotherapy.

METHODS

Sera from 204 cancer patients who were negative for HBsAg, were tested for anti-HBc antibodies. The samples that were negative for HBsAg but positive for anti-HBc also examined for HBV-DNA by polymerase chain reaction (PCR).

RESULTS

Of the 204 HBsAg negative blood samples, 11 (5.4%) samples were positive for anti-HBc antibodies. HBV-DNA was detected in 9/11 (81%) of anti-HBc positive samples. Occult HBV infection in hematological cancers was more than solid cancers, 4.8% and 4.3% respectively. There was no significant difference in HBc antibody positivity based on vaccination, previous blood transfusions, history of familial hepatitis or biochemical parameters (ALT, AST, total and direct bilirubin levels) (P>0.05).

CONCLUSION

Screening of occult HBV infection by HBsAg, HBV DNA and anti HB core antibody should be suggested as a routine investigation in cancer patients before receiving chemotherapy.

Update on occult hepatitis B virus infection

The event of mutations in the surface antigen gene of hepatitis B virus (HBV) results in undetectable hepatitis B surface antigen with positive/negative anti-hepatitis B core (anti-HBc) antibody status in serum and this phenomenon is named occult hepatitis B infection (OBI). The presence of anti-HBc antibody in serum is an important key for OBI tracking, although about 20% of OBI cases are negative for anti-HBc antibody. The diagnosis of OBI is mainly based on polymerase chain reaction (PCR) and real-time PCR assays. However, real-time PCR is a more reliable method than PCR. OBI is a great issue for the public health problem and a challenge for the clinical entity worldwide. The persistence of OBI may lead to the development of cirrhosis and hepatocellular carcinoma. With regard to OBI complications, the screening of HBV DNA by the highly sensitive molecular means should be implemented for: (1) patients with a previous history of chronic or acute HBV infection; (2) patients co-infected with hepatitis C virus/human immunodeficiency virus; (3) patients undergoing chemotherapy or anti-CD20 therapy; (4) recipients of organ transplant; (5) blood donors; (6) organ transplant donors; (7) thalassemia and hemophilia patients; (8) health care workers; (9) patients with liver related disease (cryptogenic); (10) hemodialysis patients; (11) patients undergoing lamivudine or interferon therapy; and (12) children in time of HBV vaccination especially in highly endemic areas of HBV. Active HBV vaccination should be implemented for the close relatives of patients who are negative for OBI markers. Thus, the goal of this review is to evaluate the rate of OBI with a focus on status of high risk groups in different regions of the world.

Occult HBV infection in the oncohematological setting

INTRODUCTION

Occult hepatitis B infection (OBI), a virological condition characterized by a low release of Hepatitis B Virus (HBV) from liver cells and low HBV-DNA levels in serum and/or liver tissue of HBsAg-negative subjects, may reactivate in oncohematological patients undergoing immunosuppression by aggressive chemotherapy or hematopoietic stem cell transplantation. The entity of OBI reactivation varies from an increase in HBV replication without liver damage to an active HBV replication followed by liver cell necrosis, frequently severe and in some cases life threatening. Because of a possible severe outcome associated with OBI reactivation (hepatic failure or death due to the discontinuation of chemotherapy), prophylaxis with anti-HBV nucleot(s)ide analogues is recommended in relation to the foreseeable degree of immunosuppression.

MATERIALS AND METHODS

This review article focuses on the clinical impact of OBI in the oncohematological setting and is addressed to all health care workers having in care oncohematological patients or involved in the treatment of HBV infection and OBI prophylaxis.

CONCLUSION

International guidelines have indicated lamivudine prophylaxis in hematopoietic stem cell transplantation and when high-dose corticosteroids or anti-CD20 or anti-CD52 monoclonal antibodies are used. Entecavir or tenofovir should replace lamivudine for patients with advanced liver diseases for whom reactivation of OBI may be life threatening. When anti-CD20 or anti-CD52 sparing schedules or other non-aggressive chemotherapies are used, monitoring may be indicated, but very early treatment with highly effective antiviral drugs (entecavir or tenofovir) should be administered once a reactivation of OBI has occurred.

The effect of anticancer therapy on anti-hepatitis B antibody titres in patients with haematological malignancies and solid tumours

Objective

To investigate the effect of immunosuppressive anticancer therapy on titre levels of anti-hepatitis B surface antibodies (anti-HBs) in hepatitis B surface antigen (HBsAg) negative and anti-HBs positive patients with haematological malignancies or solid tumours.

Methods

This retrospective study reviewed the medical records of patients with haematological malignancies or solid tumours. Pretreatment HBsAg negative and anti-HBs positive patients were included in the analysis. Anti-hepatitis B core antibody status was used to evaluate vaccinated patients and those with resolved HBV infections.

Results

The medical records of 237 patients were reviewed retrospectively. The median anti-HBs titre decreased significantly after anticancer therapy compared with the pretreatment median anti-HBs titre in all patients (71 mIU/ml versus 57 mIU/ml). Anti-HBs titre decreased significantly in patients with haematological malignancies (70 mIU/m versus 37 mIU/ml) and in patients administered rituximab-based chemotherapy (67 mIU/ml versus 33 mIU/ml) following chemotherapy, whereas there was no significant change in patients with solid tumours. After chemotherapy, patients with low pretreatment anti-HBs titres (<100 mIU/ml) were more likely to become seronegative (<10 mIU/ml).

Conclusion

High levels of anti-HBs may have a protective effect against the reactivation of HBV especially in patients with haematological malignancies who received immunosuppressive anticancer therapy.

A comparison of lamivudine vs entecavir for prophylaxis of hepatitis B virus reactivation in allogeneic hematopoietic stem cell transplantation recipients: a single-institutional experience

The aim of this study was to compare the efficacy of lamivudine vs entecavir in the prevention of hepatitis B virus (HBV) reactivation in HBV surface Ag (HBsAg)-positive patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). A total of 216 consecutive patients were enrolled and retrospectively reviewed. Of these patients, 119 received lamivudine and 97 received entecavir. The median treatment duration to complete virological response in patients with baseline HBV-DNA levels >10(5) copies/mL was 2.0 months in the entecavir group, significantly shorter than that of the lamivudine group. After a median follow-up of 24 months post transplantation, the cumulative incidence rates of HBV reactivation at 6, 12 and 24 months following transplantation were 3.0%, 7.0% and 24.0% in the lamivudine group, and 0%, 0% and 2.0% in the entecavir group, respectively. In addition, entecavir treatment was associated with lower cumulative incidence rates of severe hepatitis caused by HBV reactivation. Mutations leading to drug resistance were detected in 25 patients in the lamivudine group and in only one patient in the entecavir group. Our data indicate that compared with lamivudine, entecavir has more potent antiviral efficacy and may be a better choice for prophylaxis of HBV reactivation in HBsAg-positive allo-HSCT recipients.

Hepatitis B reactivation in HBsAg-negative/HBcAb-positive patients receiving rituximab for lymphoma: a meta-analysis

Patients with chronic hepatitis B (HBsAg-positive) are at risk of viral reactivation if rituximab is administered without antiviral treatment, a potentially fatal complication of treatment. Patients with so-called 'resolved hepatitis B virus infection' (HBsAg-negative/cAb-positive) may also be at risk. We performed a systematic review of the English and Chinese language literature to estimate the risk of hepatitis B virus (HBV) reactivation in HBsAg-negative/cAb-positive patients receiving rituximab for lymphoma. A pooled risk estimate was calculated for HBV reactivation. The impact of HBsAb status and study design on reactivation rates was explored. Data from 578 patients in 15 studies were included. 'Clinical HBV reactivation', (ALT >3 × normal and either an increase in HBV DNA from baseline or HBsAg seroreversion), was estimated at 6.3% (I(2) = 63%, P = 0.006). Significant heterogeneity was detected. Reactivation rates were higher in prospective vs retrospective studies (14.2% vs 3.8%; OR = 4.39, 95% CI 0.83-23.28). Exploratory analyses found no effect of HBsAb status on reactivation risk (OR = 0.083; P = 0.151). Our meta-analysis confirms a measurable and potentially substantial risk of HBV reactivation in HBsAg-negative/cAb-positive patients exposed to rituximab. However, heterogeneity in the existing literature limits the generalizability of our findings. Large, prospective studies, with uniform definitions of HBV reactivation, are needed to clarify the risk of HBV reactivation in HBsAg-negative/cAb-positive patients.

Radiation-induced hepatitis B virus reactivation in hepatocellular carcinoma: A case report

Hepatitis B virus (HBV) reactivation associated with radiotherapy is rare. The present study reports the case of a 46-year-old man that experienced fatal HBV reactivation. The patient suffered from hepatocellular carcinoma (HCC) with portal vein tumor thrombus, which was treated by radiotherapy at a daily fraction of 2 Gy over 5 weeks, up to a total radiation dose of ~50 Gy. The patient presented with fatigue, yellow sclera and abdominal distension ~8 weeks subsequent to the administration of radiotherapy. The liver function tests, including the level of total bilirubin and prothrombin time, suggested acute-on-chronic liver failure. The serum HBV-DNA level had also increased between undetectable levels and 7.2×10⁴ copies/ml. Although the present patient with HCC was treated with 0.5 mg/day entecavir for 8 weeks, in addition to radiotherapy, radiation-induced HBV reactivation occurred. The condition of the patient worsened gradually. The present study emphasizes the importance of liver function and HBV-DNA screening and pre-emptive antiviral prophylaxis prior to radiotherapy in patients with HCC.

HIV-related hematological malignancies: a concise review

HIV (Human Immunodeficiency Virus) and its consequence, AIDS (acquired immunodeficiency syndrome) are responsible for a human tragedy of incalculable proportions. Patients afflicted by it are susceptible due to an early senescence of the immune system to opportunistic infections and malignancies. Since the introduction in 1996 of highly active anti-retroviral therapy (HAART), the landscape of malignancies associated to HIV/AIDS has changed in a significant manner as a direct result of significant improvement in the morbidity, mortality and life expectancy of HIV infected patients. While there has been a significant decrease in developed countries of malignancies such as Kaposi's sarcoma and Primary CNS lymphomas associated to the pre-HAART HIV-related immunodeficiency, hematological malignancies, particularly non-Hodgkin lymphomas continue to be the most common cancer-related cause of death in HIV infected individuals. This concise review of the subject highlights aspects of the natural history of HIV disease as it relates to the cause of malignancies with emphasis in the management and treatment of HIV-related hematological malignancies.

Giving rituximab in patients with occult or resolved hepatitis B virus infection: are the current guidelines good enough?

INTRODUCTION

Hepatitis B virus (HBV) reactivation after 'resolved' infection can occur in the setting of immunosuppression, including iatrogenically induced by anti-CD20 antibodies. The presence of antibodies against the HBV core antigen (anti-HBc) is a marker of risk for this phenomenon. The risk of this occurring in patients with circulating HBV surface antigen (HBsAg) is well characterized, but is less well characterized in patients who are HBsAg negative.

AREAS COVERED

This article reviews the literature regarding HBV reactivation in the context of rituximab therapy. We have limited our review to HBsAg-negative patients, and clinical outcomes following HBV reactivation.

EXPERT OPINION

We have recommended prophylactic anti-viral therapy for all HBsAg-negative/anti-HBc-positive patients undergoing rituximab therapy in combination with other immunosuppressive therapy.

Prevalence, characteristics and management of occult hepatitis B virus infection in patients with chronic lymphocytic leukemia: a single center experience

Several reports have emphasized the risk of hepatitis B virus (HBV) reactivation in patients with lymphoproliferative disorders undergoing cytotoxic treatment. To determine the prevalence of occult B infection (OBI) in a population with chronic lymphocytic leukemia (CLL) and management with universal prophylaxis (UP) in all patients undergoing chemoimmunotherapy or targeted prophylaxis (TP) in patients experiencing seroreversion during therapy, we analyzed 397 patients with CLL from our database. The prevalence of OBI in our patients with CLL was 8.6% (34 patients). When comparing patients with OBI/CLL with those with CLL, we did not find any statistical difference among clinical-biological parameters and time dependent endpoints except for a lower peripheral blood lymphocyte count in the OBI/CLL group (p = 0.036). From 2000 to 2010 careful follow-up and TP were adopted; two out of 10 patients (20%) showed seroreversion. From June 2010 we adopted UP during and 12 months after immunosuppressive treatment in all patients with CLL with OBI; no evidence of seroreversion was detected.

Prevalence and chemotherapy-induced reactivation of occult hepatitis B virus among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma: significance of hepatitis B core antibodies screening

BACKGROUND

Occult hepatitis B infection (OBI) is characterized by negative hepatitis B surface antigen (HBsAg) and detectable hepatitis B virus (HBV)-DNA in the liver and/or serum, with or without hepatitis B core antibody (anti-HBc). Anti-HBc is the most sensitive marker of previous HBV. HBV reactivation in patients under immunosuppressive treatment is life-threatening, occurring in both overt and occult HBV especially in hematological malignancies.

AIM OF THE WORK

To evaluate the prevalence and chemotherapy-induced reactivation of OBI among hepatitis B surface antigen negative patients with diffuse large B-cell lymphoma (DLBCL) patients and to determine the significance of anti-HBc screening among this group of patients before receiving chemotherapy.

PATIENTS AND METHODS

This cross-sectional study included 72 DLBCL patients negative for HBsAg, HBsAb and hepatitis C virus antibodies (anti-HCV). Patients were subjected to investigations including anti-HBc. All patients underwent alanine transaminase (ALT) monitoring before each cycle of chemotherapy and monthly for 12 months after the end of chemotherapy. Patients with suspected OBI were tested for HBV-DNA using real-time polymerase chain reaction (PCR).

RESULTS

Anti-HBc was detected in 10 of 72 HBsAg negative sera (13.89%) (95% confidence interval 6.9-22.2%). Five of the 10 anti-HBc positive patients in this study had OBI reactivation.

CONCLUSION

The study concluded that anti-HBc screening is mandatory before chemotherapy. HBsAg-negative/anti-HBc-positive patients should be closely observed for signs of HBV reactivation through the regular monitoring of ALT. Prophylaxis lamivudine is recommended for anti-HBc positive patients before chemotherapy.

Risk and prophylaxis strategy of hepatitis B virus reactivation in patients with lymphoma undergoing chemotherapy with or without rituximab

Hepatitis B virus (HBV) reactivation is a serious but preventable complication for patients with lymphoma receiving systemic therapy. Without antiviral prophylaxis, the HBV reactivation rate is estimated to be > 50% in patients who are positive for hepatitis B surface antigen (HBsAg), and fatal hepatic failure is not uncommon. Current guidelines suggest that routine antiviral prophylaxis should be administered to all HBsAg-positive patients until 6-12 months after completion of chemotherapy. For those who are negative for HBsAg and positive for hepatitis B core antibody, HBV reactivation is uncommon when a conventional dose of chemotherapy is administered. However, with rituximab-containing immunochemotherapy, the HBV reactivation rate is 18% and the clinical course can vary from asymptomatic viremia to fulminant hepatic failure that can be potentially fatal. In this review, we discuss the risk, clinical course and prophylactic strategy of HBV reactivation in patients with lymphoma treated with chemotherapy with or without rituximab.

Lack of evidence of viral reactivation in HBsAg-negative HBcAb-positive and HCV patients undergoing immunosuppressive therapy for psoriasis

BACKGROUND

HBV and HCV reactivation have been widely reported in patients undergoing immunosuppressive therapy (IT); however, few data are available on the risk of reactivation in patients with psoriasis receiving IT. The aim of our study was to assess the prevalence of HBV and HCV infection in patients with psoriasis and to evaluate the effects of IT during the course of the infection.

METHODS

The study included psoriatic patients who attended an Italian tertiary referral hospital from 2009 to 2012. A total of 224 patients were enrolled. We evaluated: HBV and HCV markers, type of IT and the occurrence of viral reactivation. The observational period ranged from the beginning of IT to the last visit, with a mean follow-up period of 54 months.

RESULTS

Two hundred and twenty patients (135 males and 89 females; mean age 59 years; range 18-86 years) with psoriasis, with or without psoriatic arthritis, receiving conventional IT and/or biological drugs were tested for markers of infection. We identified 23/224 patients (10.2%) with isolated positivity for HBcAb positivity, 36/224 (16%) with positivity for HBsAb/HBcAb, and 15/224 (6.6%) with positivity for HCV-Ab. No patient was HBsAg positive, none of them underwent pre-emptive therapy with lamivudine or other antiviral drugs and no one showed episodes of viral reactivation.

CONCLUSIONS

The prevalence of HBsAg in patients with psoriasis is lower than that observed in the general population. The prevalence of isolated positivity for HBcAb and of combined positivity for HBcAb and HBsAb is 10.2% and 16%, respectively. The prevalence of HCV infection (HCV-RNA+) is 4%. In patients with psoriasis and HCV-Ab or HBcAb positivity, the IT seems to be safe, regardless of the type of drugs.

Clinical impact of occult hepatitis B virus infection in immunosuppressed patients

Occult hepatitis B infection (OBI), is characterized by low level hepatitis B virus (HBV) DNA in circulating blood and/or liver tissue. In clinical practice the presence of antibody to hepatitis B core antigen in hepatitis B surface antigen (HBsAg)-/anti-HBs-negative subjects is considered indicative of OBI. OBI is mostly observed in the window period of acute HBV infection in blood donors and in recipients of blood and blood products, in hepatitis C virus chronic carriers, in patients under pharmacological immunosuppression, and in those with immunodepression due to HIV infection or cancer. Reactivation of OBI mostly occurs in anti-HIV-positive subjects, in patients treated with immunosuppressive therapy in onco-hematological settings, in patients who undergo hematopoietic stem cell transplantation, in those treated with anti-CD20 or anti-CD52 monoclonal antibody, or anti-tumor necrosis factors antibody for rheumatological diseases, or chemotherapy for solid tumors. Under these conditions the mortality rate for hepatic failure or progression of the underlying disease due to discontinuation of specific treatment can reach 20%. For patients with OBI, prophylaxis with nucleot(s)ide analogues should be based on the HBV serological markers, the underlying diseases and the type of immunosuppressive treatment. Lamivudine prophylaxis is indicated in hemopoietic stem cell transplantation and in onco-hematological diseases when high dose corticosteroids and rituximab are used; monitoring may be indicated when rituximab-sparing schedules are used, but early treatment should be applied as soon as HBsAg becomes detectable. This review article presents an up-to-date evaluation of the current knowledge on OBI.

Clinical impact of occult hepatitis B virus infection in immunosuppressed patients

Occult hepatitis B infection (OBI), is characterized by low level hepatitis B virus (HBV) DNA in circulating blood and/or liver tissue. In clinical practice the presence of antibody to hepatitis B core antigen in hepatitis B surface antigen (HBsAg)-/anti-HBs-negative subjects is considered indicative of OBI. OBI is mostly observed in the window period of acute HBV infection in blood donors and in recipients of blood and blood products, in hepatitis C virus chronic carriers, in patients under pharmacological immunosuppression, and in those with immunodepression due to HIV infection or cancer. Reactivation of OBI mostly occurs in anti-HIV-positive subjects, in patients treated with immunosuppressive therapy in onco-hematological settings, in patients who undergo hematopoietic stem cell transplantation, in those treated with anti-CD20 or anti-CD52 monoclonal antibody, or anti-tumor necrosis factors antibody for rheumatological diseases, or chemotherapy for solid tumors. Under these conditions the mortality rate for hepatic failure or progression of the underlying disease due to discontinuation of specific treatment can reach 20%. For patients with OBI, prophylaxis with nucleot(s)ide analogues should be based on the HBV serological markers, the underlying diseases and the type of immunosuppressive treatment. Lamivudine prophylaxis is indicated in hemopoietic stem cell transplantation and in onco-hematological diseases when high dose corticosteroids and rituximab are used; monitoring may be indicated when rituximab-sparing schedules are used, but early treatment should be applied as soon as HBsAg becomes detectable. This review article presents an up-to-date evaluation of the current knowledge on OBI.

Reactivation of hepatitis B virus in patients with undetectable HBsAg undergoing chemotherapy for malignant lymphoma or multiple myeloma

Despite increasing reports of hepatitis B virus (HBV) reactivation in hematological malignancies, its incidence, and risk factors are still obscure. The aim of this study was to clarify the frequency and risk factors of HBV reactivation in hepatitis B surface antigen (HBsAg) undetectable patients with malignant lymphoma or multiple myeloma, during or after chemotherapy. A total of 109 patients with undetectable HBsAg undergoing chemotherapy for malignant lymphoma or multiple myeloma were enrolled in this study. Anti-hepatitis B surface (anti-HBs) and anti-hepatitis B core (anti-HBc) were checked before treatment, and HBV DNA in sera was quantified monthly during and after chemotherapy. Out of 109 patients, 42 (38.5%) had anti-HBs and 59 (54.1%) had anti-HBc. Among the 59 anti-HBc positive patients, four patients (4/59, 6.8%) showed HBV reactivation during 20.5 median follow-up months. In all four patients with HBV reactivation, peripheral lymphocyte counts before chemotherapy were lower than those without HBV reactivation (P=0.033). HBV reactivation occurred during and after chemotherapy containing rituximab for non-Hodgkin lymphoma. Four patients, who had HBV reactivation, did not develop de novo hepatitis due to HBV reactivation and were able to undergo chemotherapy against malignant lymphoma as scheduled. Monitoring of HBV DNA in sera is useful for the early diagnosis of HBV reactivation, and preemptive therapy is an useful alternative to prevent hepatitis due to HBV reactivation. Patients must be monitored periodically for HBV-DNA levels during and after chemotherapy.

Hepatitis B virus reactivation associated with anti-neoplastic therapy

Reactivation of hepatitis B virus (HBV) infection is a known complication during and after anti-cancer therapy. This condition can affect two patient populations: it is most commonly seen in patients who are seropositive for hepatitis B surface antigen (HBsAg), but it is also being increasingly reported among patients who are HBsAg-negative but who have prior infection, as evident by seropositive status for antibody to hepatitis B core antigen (anti-HBc), irrespective of their anti-HBs (antibody to HBsAg) status. The clinical course can vary from asymptomatic hepatitis to fulminant hepatic failure that can be potentially fatal. With the increasing use of biological agents in addition to potent cytotoxic chemotherapy in the armamentarium of anti-cancer treatments, reactivation of hepatitis B has become a common clinical situation that is faced by both oncologists and hepatologists especially in HBV endemic areas. In this review, we discuss the clinical course of reactivation in the two HBV-infected sub-populations, and the role of anti-virals in the prevention and management of HBV reactivation in association with cytotoxic chemotherapy and biological therapies.

[Immunologic changes in diffuse large B-cell lymphomas after rituximab-CHOP treatment: own data and review of the literature]

INTRODUCTION

Rituximab treatment may induce a long-term B-cell depletion, which can be accompanied with an increased infection risk.

AIMS

To examine the changes of the white blood cell, CD19+ B-cell and CD4+ T-cell counts and the levels of immunoglobulin G, A, M after rituximab containing chemotherapy and to explore the infectious complications in our patients and review of the literature.

PATIENTS AND METHODS

Thirty-five diffuse large B-cell lymphoma patients were examined, who were treated with rituximab-cyclophosphamide-vincristine-doxoribicine-prednisolone (R-CHOP). The B- and T-cell populations were analyzed with flow-cytometry while the immunoglobulin levels were measured by nephelometry.

RESULTS

CD19+ B-lymphocytes were undetectable after the treatment and their count only increased from the post-therapeutic 12th month. Infection did not occur in this group of patients.

CONCLUSIONS

Rituximab induced B-cell depletion was appreciable also in this group of patients, while serious or unexpected infection did not occur. Increased infectious risk primarily can be observed after long-term, maintenance rituximab treatment.

A fatal case of hepatitis B virus (HBV) reactivation during long-term, very-low-dose steroid treatment in an inactive HBV carrier

Hepatitis B virus (HBV) may be reactivated after chemotherapy or immunosuppressive therapy, and therefore administration of antiviral agents before such treatment is recommended. Most reported cases of reactivation are associated with high doses of immunosuppressive agents or combination therapy. We present a case of a previously inactive HBV carrier with an acute severe flare-up during a long-term, very-low-dose (2.5 mg/day) steroid treatment for rheumatoid arthritis. We suggest that even a minimal dose of single-regimen oral steroid can cause reactivation of indolent, inactive HBV.

Patients with hematological malignancies and serological signs of prior resolved hepatitis B

Hepatitis B virus (HBV) infection affects a large part of the world population. Within the different virological HBV categories that have been identified, patients with occult HBV infection represent a peculiar group. These individuals harbor a replication competent virus, inhibited in its replicative function. Accordingly, cases of reactivations have been observed in immunosuppressed individuals who lose immunological control over the infection. Patients with hematological malignancies (HM) are treated with intense myelo- and immunosuppressive chemotherapy regimens which favor HBV reactivation. This event can have severe consequences, such as hepatitis flare, hepatic failure and even death. In addition, it can lead to delays or interruptions of curative treatments, resulting in a decreased disease free and overall survival. In this review, we will examine the event of HBV reactivation in patients with signs of resolved HBV infection undergoing treatment for HM and propose possible management strategies.

Reactivation of hepatitis B virus and hepatitis C virus in patients with cancer

Infections with hepatitis B virus (HBV) or hepatitis C virus (HCV) are associated with significant morbidity and mortality among patients with cancer, especially in patients with hematologic malignancies and those who undergo hematopoietic stem-cell transplantation. Reported rates of HBV reactivation in HBV carriers who undergo chemotherapy range from 14-72%. In these patients, mortality rates range from 5-52%. HCV reactivation seems to be less common than HBV reactivation and is usually associated with a good outcome and low mortality. However, once severe hepatitis develops, as a result of viral reactivation, mortality rates seem to be similar among patients infected with HBV or HCV. Liver damage owing to viral reactivation frequently leads to modifications or interruptions of chemotherapy, which can negatively affect patients' clinical outcome. Risk factors for the development of severe HBV or HCV reactivation need to be better defined to permit identification of patients who may benefit from preventive measures, early diagnosis, and therapy. In this article, we review the epidemiology, pathogenesis, risk factors, and clinical and laboratory manifestations associated with reactivation of HBV and HCV during immunosuppressive therapy. We also discuss strategies for the prevention and treatment of viral reactivation, including the management of reactivation with new antiviral agents.

Current trends in management of hepatitis B virus reactivation in the biologic therapy era

Hepatitis B virus (HBV) reactivation represents an emerging cause of liver disease in patients undergoing treatment with biologic agents. In particular, the risk of HBV reactivation is heightened by the use monoclonal antibodies, such as rituximab (anti-CD20) and alemtuzumab (anti-CD52) that cause profound and long-lasting immunosuppression. Emerging data indicate that HBV reactivation could also develop following the use of other biologic agents, such as tumor necrosis factor (TNF)-α inhibitors. When HBV reactivation is diagnosed, it is mandatory to suspend biologic treatment and start antiviral agents immediately. However, pre-emptive antiviral therapy prior to monoclonal antibody administration is crucial in preventing HBV reactivation and its clinical consequences. Several lines of evidence have shown that risk of HBV reactivation is greatly reduced by the identification of high-risk patients and the use of prophylactic antiviral therapy. In this article, we discuss current trends in the management of HBV reactivation in immunosuppressed patients receiving biologic therapy, such as rituximab, alemtuzumab and TNF-α antagonists.

Reactivation of hepatitis B virus infection after cytotoxic chemotherapy or immunosuppressive therapy

Reactivation of hepatitis B is defined as the recurrence or an abrupt rise in hepatitis B virus (HBV) replication, often accompanied by an increase in serum transaminase levels, and both events occurring in a patient with a previous inactive hepatitis B infection. This reactivation can occur in situations in which the ratio of HBV replication and immune response is altered. It can happen during the treatment of hemato-oncological malignancies with chemotherapy and in immunosuppression of autoimmune diseases. Clinical manifestations of hepatitis B reactivation are variable and can range from asymptomatic to acute hepatitis, which are sometimes serious and result in acute liver failure with risk of death, and usually occur in the periods between cycles or at the end of chemotherapy. Immunosuppressive drugs such as corticosteroids or azathioprine can induce HBV reactivation in patients carrying hepatitis B virus surface antigen (HBsAg) or anti-HBc, but much less frequently than chemotherapy treatments. The tumor necrosis factor α inhibitors infliximab, etanercept and adalimumab may cause reactivation of hepatitis B, and the overall frequency with infliximab may be similar (50%-66%) to that caused by chemotherapy. Baseline HBV serology is recommended for all patients receiving chemotherapy and immunosuppressive drugs, and HBsAg positive patients should receive anti-HBV prophylaxis to decrease virus reactivation and death rates.

Reactivation of hepatitis B virus following rituximab-plus-steroid combination chemotherapy

Reactivation of hepatitis B virus (HBV) has been reported as a fatal complication following systemic chemotherapy or other immunosuppressive therapy. The risk of HBV reactivation differs according to both the patient's HBV infection status prior to systemic chemotherapy and the degree of immunosuppression due to chemotherapy. For establishing an optimal strategy for hepatitis prevention and treatment, it is necessary to understand the characteristics, the clinical course and the risk factors for HBV reactivation and to recognize the difference between hepatitis B surface antigen (HBsAg)-positive and -negative patients with HBV reactivation. Among the important viral risk factors, HBV-DNA level and HBV-related serum markers have been reported to be associated with HBV reactivation in addition to cccDNA, genotypes and gene mutations. Rituximab-plus-steroid combination chemotherapy has recently been identified as a host risk factor for HBV reactivation in hepatitis B core antibody (anti-HBc)-positive and/or hepatitis B surface antibody (anti-HBs) positive--but nonetheless HBsAg-negative--lymphoma patients. For these patients with resolved hepatitis B, preemptive therapy guided by serial HBV-DNA monitoring is a reasonable strategy to enable early diagnosis of HBV reactivation and initiation of antiviral therapy. In this review, we summarize the characteristics of HBV reactivation following rituximab-plus-steroid combination chemotherapy, mainly in HBsAg-negative lymphoma patients, and propose a strategy for managing HBV reactivation.

Antiviral treatment including entecavir plus tenofovir disoproxil fumarate for HBV reactivation following a rituximab-based regimen

Entecavir and tenofovir disoproxil fumarate are potent and effective antiviral drugs that now represent recommended treatment options for chronic HBV infection. However, no or very limited clinical evidence is currently available on these drugs for the management of HBV reactivation in patients with haematological malignancies. Herein, we report a case of HBV reactivation in a patient with non-Hodgkin's lymphoma following a rituximab-based regimen, and who was successfully treated with a combination antiviral treatment including entecavir and tenofovir disoproxil fumarate.

A case of severe acute hepatitis C and delayed antibody production due to rituximab therapy

A 59-year-old male patient underwent surgical treatment for non-Hodgkin's lymphoma of the right scrotum in October 2007. He received a total of 4 courses of two different adjuvant chemotherapy regimens including rituximab from January to April 2008. In June 2008 he was hospitalized due to severe liver dysfunction with an alanine aminotransferase of 2039 IU/l and a prothrombin time of 23.3%. He was diagnosed with acute hepatitis C by the detection of hepatitis C virus (HCV) RNA and negative anti-HCV antibody, and his hepatic function improved with bed rest during hospitalization; however, the production of anti-HCV antibodies was not detected until January 2009. Severe liver dysfunction is uncommon among patients with acute hepatitis C, and the long window (8 months) between HCV infection and the development of anti-HCV antibodies observed in the present case may have been due, at least in part, to a B cell disorder caused by rituximab therapy. In addition to the well-known risk of reactivation of hepatitis B virus infection in patients undergoing chemotherapy, physicians should be aware of the potential effects of chemotherapy on the clinical course of HCV infection.