Hepatitis C virus infection prevalence and liver dysfunction in a cohort of B-cell non-Hodgkin's lymphoma patients treated with immunochemotherapy

The impact of hepatitis B virus and hepatitis C virus infections in patients with Hodgkin's and non-Hodgkin's lymphoma

BACKGROUND

This study aimed to determine the prevalence of HCV and occult HBV among newly diagnosed pre-treatment Egyptian lymphoma patients and evaluate patients' outcomes based on the presence of the viral infections.

METHODS

The study included 80 therapy-naïve lymphoma patients including 71 non-Hodgkin lymphoma (NHL) and 9 Hodgkin lymphoma disease (HD) in addition to 100 healthy volunteers. HBV screening using HBsAg and anti-HBc IgM and HCV using AB/Ag ELISA and real-time RT-PCR were screened in tested and control groups. The diagnosis was confirmed by histopathology. Overall survival (OS) and progression-free survival (PFS) were conducted to diseased patients.

RESULTS

Healthy patients showed 4/100, (4%) active HCV infection and 1/100, (1%) active HBV infection and no occult HBV infection. Among NHL patients, 28 were positive for HBV (6 active and 22 occult HBV infection). Occult HBV was also detected in 5/9 HD patients. HCV was detected in (30/71, 42.3%) of NHL patients and in a single HD patient. Ten occult HBV NHL patients showed a mixed infection with HCV. The incidence of both HCV and HBV are higher in NHL than HL patients. After antitumor treatment, complete remission for lymphoma was achieved in 45% of patients. Both overall survival (OS) and progression-free survival (PFS) were correlated and significantly associated with patients' LDH levels.

CONCLUSIONS

Our findings claim the suggestive role of HCV and occult HBV infections in NHL but not HL patients in comparison to healthy control, suggesting pre-screening of related factors including occult HBV in for potential better therapy response.

Severe acute exacerbation of HCV infection in cancer patients who undergo chemotherapy without antiviral prophylaxis

No guidelines have been developed for the management of HCV-infected cancer patients receiving chemotherapy. The current study aimed to investigate the incidence of severe acute exacerbation of HCV infection in cancer patients receiving chemotherapy and to search for risk factors predicting severe acute exacerbation of HCV infection. This retrospective cohort study reviewed the clinical data of the cancer patients receiving chemotherapy in our institute from August 2012 to December 2017. Incidences of severe acute exacerbation of HCV infection in different kinds of cancers were assessed, and risk factors were analysed. Cancer patients with HCV infection (n = 306) had a higher frequency of severe acute liver injury (2.3% vs 0.7%; P = .003) than those without HCV infection (n = 4419). The incidence of severe acute exacerbation in HCV-infected haematological cancer patients was higher than that in those with HCC and non-HCC solid tumours (9.4% vs 1.9% and 1.1%). Rituximab-containing chemotherapy and haematological malignancy were the risk factors related to the acute exacerbation (P < .001 and P = .004, respectively). None of the patients with severe acute HCV flares developed hepatic decompensation or mortality. However, 57.1% of them discontinued chemotherapy due to liver dysfunction. In conclusion, HCV infection increases the risk of acute severe liver injury in cancer patients undergoing chemotherapy. Rituximab-containing chemotherapy and haematological malignancy are the risk factors related to severe acute exacerbation of HCV infection in cancer patients undergoing chemotherapy. Pre-chemotherapy HCV testing is therefore mandatory before rituximab-containing chemotherapy for the treatment of haematological malignancy.

Hepatitis B and C Virus Reactivation Patterns in a Romanian Cohort of Patients with Chronic Lymphoproliferative Disorders

Hepatitis B and C virus (HBV and HCV) reactivations have become more common following the intensive use of biological therapies for the treatment of chronic lymphoproliferative disorders (CLD). We evaluate risk factors for virus reactivation and exitus in patients diagnosed with CLD and HBV or HCV infection, undergoing rituximab-chemotherapy (R-chemo). A prospective, observational study in two tertiary-care Romanian hospitals, between December 2007 and May 2010, of patients diagnosed with CLD undergoing R-chemo. HBV and HCV serological markers, viral load, fibrosis and necroinflammation were assessed at baseline and every 3-6 months. We screened 502 patients diagnosed with CLDs (77.2% non-Hodgkin lymphomas) and enrolled 57 patients with HBV and/or HCV infection with a mean age of 61.35 ± 11.1 years. The replicative virus was HBV in 23 patients (40.3%), HCV in 33 patients (57.9%). HCV reactivation rate (15.6%) was lower than for HBV (45.5%) (p = 0.02). In univariate analysis, viral reactivation was associated with aggressive CLD (p = 0.01), HBV (p = 0.01) and lymphopenia (p = 0.02). Death was associated with aggressive CLD (p = 0.01), viral reactivation (p = 0.001) and high baseline viremia (p = 0.05). In multivariate analysis, viral reactivation was associated with lymphopenia (OR 0.05, 95% CI 0.003-0.85, p = 0.03). Risk of death was 10 times higher for patients with viral reactivation (95% CI 1.54-65.5, p = 0.01). A quarter of the infected patients were diagnosed with viral reactivation. While hepatitis C was more prevalent than hepatitis B in patients with CLD, viral reactivation was found 3 times more frequently in patients with hepatitis B than C.

Reactivation of Hepatitis C Virus and Its Clinical Outcomes in Patients Treated with Systemic Chemotherapy or Immunosuppressive Therapy

Background/Aims

According to the results of several studies, the outcome of hepatitis C virus (HCV) reactivation is not as severe as the outcome of hepatitis B virus reactivation. The aim of this study was to evaluate the effect of pharmacological immunosuppression on HCV reactivation.

Methods

The medical records of patients who underwent systemic chemotherapy, corticosteroid therapy, or other immunosuppressive therapies between January 2008 and March 2015 were reviewed. Subsequently, 202 patients who were seropositive for the anti-HCV antibody were enrolled. Exclusion criteria were: unavailability of data on HCV RNA levels, a history of treatment for chronic hepatitis C, and the presence of liver diseases other than a chronic HCV infection.

Results

Among the 120 patients enrolled in this study, hepatitis was present in 46 patients (38%). None of the patients were diagnosed with severe hepatitis. Enhanced replication of HCV was noted in nine (27%) of the 33 patients who had data available on both basal and follow-up HCV RNA loads. Reappearance of the HCV RNA from an undetectable state did not occur after treatment. The cumulative rate of enhanced HCV replication was 23% at 1 year and 30% at 2 years.

Conclusions

Although enhanced HCV replication is relatively common in HCV-infected patients treated with chemotherapy or immunosuppressive therapy, it does not lead to serious sequelae.

Acute exacerbation of hepatitis C in hepatocellular carcinoma patients receiving chemotherapy

Acute hepatitis C exacerbations can occur in cancer patients carrying hepatitis C virus (HCV) when receiving systemic chemotherapy. However, clinical studies evaluating these complications remain rare due to the lack of clinically proven effective and tolerable anti-HCV treatments at late cancer stages. Furthermore, no data were available regarding hepatitis C exacerbation in advanced hepatocellular carcinoma (HCC) patients receiving chemotherapy. To address this issue, 48 patients with HCV-related advanced HCC, who underwent systemic chemotherapy using 5- fluorouracil, cisplatin, and mitoxantrone from 2008 to 2014 were analyzed. Nine patients developed acute hepatitis exacerbations defined by HCV-RNA elevation ≥10-fold and alanine transaminase (ALT) elevation ≥5-fold of the upper normal limit. Six were genotype 1b and 3 were genotype 2. Three patterns of clinical courses were observed including single episode of exacerbation (n = 5), fluctuated flares (n = 3), and delayed exacerbation (n = 1). Hepatic failure developed in five patients. Patients with acute exacerbations were less likely to have pretreatment ascites (11.1% vs. 53.8%; P = 0.028) and displayed a lower baseline ALT (44.1 ± 28.5 U/L vs. 72.6 ± 19.2 U/L; P = 0.007). Paradoxically, despite a high risk of hepatic failure, occurrence of hepatitis C exacerbation was associated with a favorable overall survival (P = 0.027; 22.8 vs. 5.4 months). In conclusion, hepatitis C exacerbation can occur in HCC patients receiving chemotherapy, leading to liver failure. However, the flare was associated with a better overall survival, possibly due to its association with a better baseline liver function. J. Med. Virol. 89:153-160, 2017. © 2016 Wiley Periodicals, Inc.

Critical appraisal of rituximab in the maintenance treatment of advanced follicular lymphoma

Rituximab is an IgG1, chimeric monoclonal antibody specifically designed to recognize the CD20 antigen expressed on the surface of normal and malignant B-lymphocytes, from the B-cell precursor to the mature B-cells of the germinal center, and by most neoplasms derived from B-cells. After 2 decades of use, rituximab is firmly positioned in the treatment of follicular lymphoma (FL), both in the front line and in the relapsing disease, improving previous results by including it in classical chemotherapy regimens. However, the pharmacology of rituximab continues to generate controversial issues especially regarding the mechanisms of action in vivo. The contribution of rituximab as a maintenance treatment in FL has been significant progress in the management of this disease without an increase in side effects or a decrease in the quality of life of patients. With the widespread use of rituximab, there are new security alerts and side effects not previously detected in the pivotal trials that clinicians should learn to recognize and manage. In this article, we will review the pharmacokinetics and pharmacodynamics of rituximab, the management issues in the treatment of advanced FL focusing on maintenance rituximab, its long-term efficacy and safety profile, and its effect on the quality of life.

Incidence and antiviral response of hepatitis C virus reactivation in lupus patients undergoing immunosuppressive therapy

Objective

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease and usually requires immunosuppressive therapy, which is a major cause of viral reactivation. The incidence and antiviral response in SLE patients with hepatitis C virus (HCV) reactivation is unclear and needs to be investigated.

Methods

One hundred and sixty-six SLE patients with antibody to HCV (anti-HCV) status were retrospectively reviewed regarding the events of HCV reactivation. Patients with HCV reactivation were treated with pegylated interferon plus ribavirin treatment. The virological response and relapse rate were evaluated.

Results

Twenty-six patients were positive for anti-HCV. During a mean 8.4 years of follow-up, 10 (38.5%) cases developed HCV reactivation. No clear relationship was noted between immunosuppressive therapy and the HCV reactivation. Eight patients underwent antiviral therapy and the rapid virological response (RVR), early virological response, and sustained virological response (SVR) rates were 37.5%, 87.5%, and 75.0%, respectively. However, late relapse (reappearance of HCV RNA in serum after archiving SVR) was found in two (33.3%) of six patients achieving SVR. The two cases were HCV genotype 1 b concurrent with corticosteroid treatment.

Conclusions

HCV reactivation in anti-HCV-positive SLE patients was possibly associated with glucocorticoids. The virological response to interferon plus ribavirin treatment is not inferior to the general population. However, monitoring HCV RNA after SVR is necessary for patients concurrent with corticosteroid treatment due to the risk of late relapse.

Hepatitis C virus syndrome: A constellation of organ- and non-organ specific autoimmune disorders, B-cell non-Hodgkin's lymphoma, and cancer

The clinical course of chronic hepatitis C virus (HCV) infection is characterized by possible development of both liver and extrahepatic disorders. The tropism of HCV for the lymphoid tissue is responsible for several immune-mediated disorders; a poly-oligoclonal B-lymphocyte expansion, commonly observed in a high proportion of patients with HCV infection, are responsible for the production of different autoantibodies and immune-complexes, such as mixed cryoglobulins. These serological alterations may characterize a variety of autoimmune or neoplastic diseases. Cryoglobulinemic vasculitis due to small-vessel deposition of circulating mixed cryoglobulins is the prototype of HCV-driven immune-mediated and lymphoproliferative disorders; interestingly, in some cases the disease may evolve to frank malignant lymphoma. In addition, HCV shows an oncogenic potential as suggested by several clinico-epidemiological and laboratory studies; in addition to hepatocellular carcinoma that represents the most frequent HCV-related malignancy, a causative role of HCV has been largely demonstrated in a significant percentage of patients with isolated B-cells non-Hodgkin's lymphomas. The same virus may be also involved in the pathogenesis of papillary thyroid cancer, a rare neoplastic condition that may complicate HCV-related thyroid involvement. Patients with HCV infection are frequently asymptomatic or may develop only hepatic alteration, while a limited but clinically relevant number can develop one or more autoimmune and/or neoplastic disorders. Given the large variability of their prevalence among patients' populations from different countries, it is possible to hypothesize a potential role of other co-factors, i.e., genetic and/or environmental, in the pathogenesis of HCV-related extra-hepatic diseases.

Hepatitis C virus and diffuse large B-cell lymphoma: Pathogenesis, behavior and treatment

A significant association between hepatitis C virus (HCV) infection and B-cell lymphoma has been reported by epidemiological studies, most of them describing a strong relationship between indolent lymphomas and HCV. Furthermore, the curative potential of antiviral therapy on HCV related indolent lymphomas supports a specific role for the virus in lymphomagenesis. These observations are reinforced by numerous laboratory experiments that led to several hypothetical models of B-cell transformation by HCV. Diffuse large B-cell lymphoma (DLBCL), the most common lymphoma subtype in the western countries, has been associated to HCV infection despite its aggressive nature. This association seems particularly prominent in some geographical areas. Clinical presentation of HCV-associated DLBCL has consistently been reported to differ from the HCV-negative counterpart. Nevertheless, histopathology, tolerance to standard-of-care chemo-immunotherapy (R-CHOP or CHOP-like regimens) and final outcome of HCV-positive DLBCL patients is still matter of debate. Addition of rituximab has been described to enhance viral replication but the probability of severe hepatic complications remains low, with some exceptions (i.e., hepatitis B virus or immune immunodeficiency virus co-infected patients, presence of grade > 2 transaminases elevation, cirrhosis or hepatocarcinoma). HCV viral load in this setting is not necessarily directly associated with liver damage. Overall, treatment of HCV associated DLBCL should be performed in an interdisciplinary approach with hepatologists and hematologists with close monitoring of liver function. Available reports reveal that the final outcome of HCV-positive DLBCL that receive standard immunochemotherapy is not inferior to their HCV-negative counterpart. This review summarizes data on epidemiology, pathogenesis and therapeutic approach on HCV-associated DLBCL. Several issues that are matter of debate like clinical management of patients with transaminase elevation, criteria for discontinuing or starting immuno-chemotherapy, as well as the exact role of monoclonal antibodies will be analyzed.

Hepatitis C virus reactivation in cancer patients in the era of targeted therapies

The purpose of this review is to summarize the evidence of hepatitis C reactivation in cancer patients in the era of targeted therapies. Targeted therapies are novel therapeutics frequently used in cancer patients. During treatment with targeted therapies, viral replication is one of the major problems that can occur. The PubMed database, ASCO, and ASCO Gastrointestinal Cancer Symposium abstracts were searched up until September 15, 2013 using the following search keywords: “targeted therapies, rituximab, alemtuzumab, brentuximab, hepatitis, hepatitis C reactivation, tyrosine kinase inhibitors, imatinib, mammalian target of rapamycin (mTOR) inhibitors, everolimus, anti-HER therapies, trastuzumab, pertuzumab, lapatinib, anti-epidermal growth factor receptor therapies, cetuximab, panitumumab, and ipilimumab”. Papers considered relevant for the aim of this review were selected by the authors. The data about rituximab-induced hepatic flare in hepatitis C virus (HCV) positive patients is controversial. However, there is the possibility of life-threatening hepatic flare that can develop after HCV ribonucleic acid (HCV-RNA) viral load increases. Routine follow-up of liver function tests should be advised. Especially in high-risk patients, such as those with baseline chronic active hepatitis and cirrhosis, and where there are plans to administer rituximab concomitantly with corticosteroids, it is advised to have close follow-up of HCV viral load. The data is insufficient to make accurate statements about the association of alemtuzumab therapy and HCV reactivation. However, alemtuzumab may cause deep immunosuppression. Due to this, it is better to follow up with liver function tests and HCV RNA levels during alemtuzumab therapy. Brentuximab has effects on antibody dependent cellular toxicity and may decrease humoral immunity. Thus, we believe that during brentuximab treatment of HCV infected patients, clinicians may encounter hepatitis C reactivation. There have been no reported cases of hepatitis C reactivation with imatinib therapy. However, there are many reports of hepatitis B reactivation with imatinib treatment. Based on the evidence of hepatitis B reactivation with imatinib and the effects of imatinib on immune system functions, we suggest that imatinib therapy might be a risk factor for HCV reactivation. Anti-human epidermal growth factor receptor 2 therapies are not associated with hepatic flare in HCV infected patients. Post-transplant studies reported that mTOR was safely administered to patients with active hepatitis C without causing hepatic flare. Cetuximab and panitumumab have not been associated with HCV reactivation. Two cases of HCV infected melanoma were safely treated with ipilimumab without any HCV reactivation or hepatic flare. Targeted therapies are a new and emerging area of oncology treatment modalities. While treating HCV infected cancer patients, clinicians should be mindful of the immunosuppressive properties of targeted therapies. Further randomized trials are needed to establish algorithms for this issue.

Anti-CD20 monoclonal antibodies and associated viral hepatitis in hematological diseases

Over the past decade, the administration of anti-CD20 monoclonal antibodies such as rituximab has demonstrated various degrees of effectiveness and has improved patients’ outcomes during the treatment of autoimmune hematological disorders and hematological malignancies. However, the depletion of B-cells, the distribution of T-cell populations, and the reconstruction of host immunity resulting from the use of anti-CD20 monoclonal antibodies potentially lead to severe viral infections, such as hepatitis B virus (HBV), hepatitis C virus (HCV), parvovirus B19, and herpes viruses, in patients who are undergoing immune therapy or immunochemotherapy. Of these infections, HBV- and HCV-related hepatitis are a great concern in endemic areas because of the high morbidity and mortality rates in untreated patients. As a result, prophylaxis against HBV infection is becoming a standard of care in these areas. Parvovirus B19, a widespread pathogen that causes red blood cell aplasia in immunocompromised hosts, also causes hepatitis in healthy individuals. Recently, its association with hepatitis was recognized in a patient treated with rituximab. In addition, adenovirus, varicella-zoster virus, hepatitis E virus, and rituximab itself have been linked to the occurrence of hepatitis during or after rituximab treatments. The epidemiologies and pathogeneses of these etiologies remain unknown. Because of the increasing use of anti-CD20 monoclonal antibodies for the treatment of hematological malignancies or autoimmune hematological disorders, it is imperative that physicians understand and balance the risks of hepatotropic virus-associated hepatitis against the benefits of using anti-CD20 monoclonal antibodies.

Liver abnormalities in the immunosuppressed

The immunosuppressed state may arise due to medical illness or drug therapy, which can result in a diverse array of liver derangements. This article discusses the commonly-encountered immunosuppressed conditions and the associated specific liver diseases. Due to the frequency of blood-borne viral disease globally, viral hepatitis (hepatitis B and C) during chemotherapy, transplantation and the increasingly utilised biological therapies for autoimmune disorders is discussed. An overview of human immunodeficiency virus co-infection with hepatitis B and C is provided. This article aims to highlight the variety of liver diseases which can occur in clinically relevant, particularly iatrogenic, immunosuppressed conditions, and summarise learning and practice points for clinicians. Recognition and prevention of viral liver disease is crucial and early involvement of experts prior to administration of immunosuppressive therapy is advised.

Reactivation of hepatitis viruses following immunomodulating systemic chemotherapy

Reactivation of hepatitis B virus (HBV) or hepatitis C virus (HCV) infection following anticancer chemotherapy and immunosuppressive therapy is a well-known complication. HBV reactivation has been reported to be associated with anti-CD20 monoclonal antibody rituximab-containing chemotherapy and tumor necrosis factor-α inhibitor-containing immunosuppressive therapy in HBV resolved patients (hepatitis B surface antigen negative and antibodies against hepatitis B core antigen positive and/or antibodies against surface antigen positive). On the other hand, HCV reactivation has been reported to be associated with liver damage or hepatic dysfunction, but fulminant hepatitis due to HCV reactivation is a rare complication. In this review, we describe the pathophysiology of the reactivation of HBV and HCV infection, as well as the clinical evidence and management of HCV reactivation.

Acute exacerbation and reactivation of chronic hepatitis C virus infection in cancer patients

BACKGROUND & AIMS

Data on acute exacerbation and reactivation of chronic hepatitis C virus (HCV) infection following chemotherapy are very limited. We sought to characterize the episodes of acute exacerbation and viral reactivation of HCV infection in cancer patients.

METHODS

The medical records of HCV-infected patients seen at our institution (2008-2009) were analyzed retrospectively. Acute exacerbation was defined as greater than 3-fold increase in serum level of alanine aminotransferase, and viral reactivation as ≥ 1 log(10) IU/ml increase of HCV viral load following chemotherapy.

RESULTS

Acute exacerbation occurred in 33 (11%) of 308 patients with proven HCV infection. Patients with acute exacerbation more often had underlying hematological malignancies (73% vs. 29%; p<0.001) and lymphopenia (6% vs. 0%; p=0.01) than patients without it. In multivariate analysis, underlying hematological malignancies (p=0.02; odds ratio, 3.2; 95% confidence interval, 1.2-8.7) and use of rituximab (p=0.004; odds ratio, 4.2; 95% confidence interval, 1.6-10.9) were associated with acute exacerbation. Patients with acute exacerbation received higher median cumulative dose of rituximab than those without exacerbation. Discontinuation of chemotherapy due to liver dysfunction was more common in patients with acute exacerbation than in patients without it (45% vs. 11%; p<0.001). Eight (36%) of 22 patients with known pre- and post-chemotherapy viral load had viral reactivation.

CONCLUSIONS

Acute exacerbation and reactivation of chronic HCV infection occur often after chemotherapy. Liver dysfunction can lead to discontinuation of potentially life-saving chemotherapy in nearly one-half of the patients with exacerbation of HCV infection.

Hepatitis C virus infection in the immunocompromised host: a complex scenario with variable clinical impact

The relationship between Hepatitis C Virus (HCV) infection and immunosuppression is complex and multifaceted. Although HCV-related hepatocytolysis is classically interpreted as secondary to the attack by cytotoxic T lymphocytes against infected cells, the liver disease is usually exacerbated and more rapidly evolutive in immunosuppressed patients. This generally occurs during the immunosuppression state, and not at the reconstitution of the host response after immunosuppressive therapy discontinuation. The field of immunosuppression and HCV infection is complicated both by the different outcome observed in different situations and/or by contrasting data obtained in the same conditions, with several still unanswered questions, such as the opportunity to modify treatment schedules in the setting of post-transplant follow-up. The complexity of this field is further complicated by the intrinsic tendency of HCV infection in itself to lead to disorders of the immune system. This review will briefly outline the current knowledge about the pathogenesis of both hepatic and extrahepatic HCV-related disorders and the principal available data concerning HCV infection in a condition of impairment of the immune system. Attention will be especially focused on some conditions - liver or kidney transplantation, the use of biologic drugs and cancer chemotherapy - for which more abundant and interesting data exist.

Efficient palliative involved-field radiotherapy on highly progressive diffuse large B-cell primary gastric lymphoma with liver cirrhosis

We report the case of a 73-year-old woman having diffuse large B-cell primary gastric lymphoma with a cirrhotic liver caused by hepatitis C virus infection. She visited our hospital with symptoms of nausea and vomiting, which appeared to be caused by stenosis due to the tumor. Metastatic tumors were seen in the gastric and jugular lymph nodes. The clinical stage was IVB with a high risk of poor prognosis according to the international index. Because of poor hepatic reserve function, standard chemotherapy could not be administered. To maintain her quality of life, palliative involved-field radiotherapy was performed. The symptoms and tumor markers significantly improved, and computed tomography and endoscopy indicated the disappearance of the primary gastric tumor. Two months after radiotherapy and her return home, she died of pneumonia. Autopsy showed neither lymphoma cells nor stenosis of gastric lesion. The significant anti-tumor effect on primary tumor in our case suggests that the involved-field radiotherapy, although palliative, can be a therapeutic option for primary gastric lymphoma patients with various complications.

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.