Hepatitis B virus reactivation in patients receiving chemotherapy for malignancies: role of precore stop-codon and basic core promoter mutations

Roles of Hepatitis B Virus Mutations in the Viral Reactivation after Immunosuppression Therapies

Reactivation of hepatitis B virus (HBV) is a major problem in patients receiving chemotherapy for malignant diseases or immunosuppression therapies. It has been thought that a reduction in the immune responses might result in the reactivation of HBV replication from covalently closed circular DNA (cccDNA) residing in hepatocytes. However, not only the host’s immune status, but also viral mutations have been reported to be associated with reactivation. Especially, several case reports about amino acid mutations in hepatitis B surface antigen (HBsAg) that escape from immune reactions have been reported, and recent reports showed that the frequencies of such mutations are higher than previously expected. In this review, we summarize the characteristics of viral mutations, including immune escape mutations in HBV-reactivated patients, and discuss their significance.

Hepatitis B virus (HBV) reactivation-The potential role of direct-acting agents for hepatitis C virus (HCV)

Hepatitis C virus (HCV) is known to inhibit hepatitis B virus (HBV) replication in patients with HBV/HCV coinfection. Reactivation of HBV in patients treated for HCV with direct-acting agents (DAAs) has emerged recently as an important clinical consideration. A growing number of case reports and case series support the association between new HCV treatments and HBV reactivation. Yet, very little is known about the specific viral characteristics that facilitate reactivation as functional characterization of the reactivated HBV has been conducted only rarely. This review provides the most recent data on HBV reactivation in the context of DAA initiation and highlights the existing viral genomic data from reactivating viruses. Current functional studies of HBV reactivation are largely limited by the retrospective identification of cases, no standardization of genomic regions that are studied with respect to HBV reactivation, and the lack of inclusion of nonreactivating controls to establish specific viral mutations that are associated with HBV reactivation. Importantly, none of these sequencing studies included cases of HBV reactivation after initiation of DAAs. While new HCV treatments have revolutionized care for HCV infected patients, HBV reactivation will likely increase in frequency, as DAAs are more commonly prescribed. Pretreatment determination of HBV status and thoughtful management of HBV coinfections will be necessary and lead to improved patient safety and yield optimal treatment results.

Genetic variation of hepatitis B virus and its significance for pathogenesis

Hepatitis B virus (HBV) has a worldwide distribution and is endemic in many populations. Due to its unique life cycle which requires an error-prone reverse transcriptase for replication, it constantly evolves, resulting in tremendous genetic variation in the form of genotypes, sub-genotypes, and mutations. In recent years, there has been considerable research on the relationship between HBV genetic variation and HBV-related pathogenesis, which has profound implications in the natural history of HBV infection, viral detection, immune prevention, drug treatment and prognosis. In this review, we attempted to provide a brief account of the influence of HBV genotype on the pathogenesis of HBV infection and summarize our current knowledge on the effects of HBV mutations in different regions on HBV-associated pathogenesis, with an emphasis on mutations in the preS/S proteins in immune evasion, occult HBV infection and hepatocellular carcinoma (HCC), mutations in polymerase in relation to drug resistance, mutations in HBV core and e antigen in immune evasion, chronicalization of infection and hepatitis B-related acute-on-chronic liver failure, and finally mutations in HBV x proteins in HCC.

Horizontal transmission of de novo hepatitis B between spouses: A case report

We report a female patient with acute hepatitis B due to horizontal transmission of hepatitis B virus from her husband, who suffered from de novo hepatitis B. A 48-year-old man underwent peripheral blood stem cell transplantation (PBSCT) for adult T-cell leukemia/lymphoma. Nine months after the initial treatment, he was referred to our hospital because of jaundice. Laboratory data showed elevated serum aminotransferase levels and hepatitis B surface antigen (HBsAg) positivity. We diagnosed de novo hepatitis B because a pre-PBSCT serum sample was negative for HBsAg and positive for anti-hepatitis B core antibody (HBcAb). His liver function improved with entecavir therapy. Two months after his diagnosis of hepatitis B, his 31-year-old wife was admitted with fever and appetite loss. She was diagnosed with acute hepatitis B because of increased serum aminotransferase levels and HBsAg and immunoglobulin M HBcAb positivity. Sequencing of HBV DNA in the serum obtained from both patients showed 99.9% homology. Therefore, we diagnosed her acute hepatitis B as due to horizontal transmission of de novo hepatitis B from her husband. HBV derived from de novo hepatitis B should be considered a potential source of infection, although intrafamilial transmission of de novo hepatitis B is rare.

Hepatitis B virus reactivation in HBsAg-negative patients is associated with emergence of viral strains with mutated HBsAg and reverse transcriptase

BACKGROUND/AIMS

Virological factors associated with hepatitis B virus reactivation (HBV-R), following chemotherapy for cancer in hepatitis B surface antigen (HBsAg)-negative patients, are not well known.

MATERIALS AND METHODS

HBV strains from 16 patients presenting HBV-R following chemotherapy were studied and compared to those obtained from 51 HBV chronically-infected patients.

RESULTS

HBsAg variability was significantly increased within the major hydrophilic region, the a determinant and the C-terminal region. Amino acid substitutions were more frequently found in HBV-R patients as compared to controls at 17 and 11 positions within HBsAg and HBV-RT, respectively. This resulted in atypical serological testing in 56% of patients and detection of resistance mutation to nucleoside analogs in 12.5%.

CONCLUSION

HBsAg and HBV-RT mutations are frequently encountered in patients with HBV-R, resulting in atypical serological testing and emergence of HBV strains resistant to nucleos(t)ides analogs.

Chemotherapy-related reactivation of hepatitis B infection: Updates in 2013

Hepatitis B reactivation is a potentially serious complication of anticancer chemotherapy, which occurs during and after therapy. This condition affects primarily hepatitis B surface antigen (HBsAg)-positive patients, but sometimes HBsAg-negative patients can be at risk, based only on evidence of past infection or occult infection with a low titer of detectable hepatitis B virus (HBV) DNA. The clinical outcomes vary with the different degrees of virologic and biochemical rebound, ranging from asymptomatic elevations in liver enzymes to hepatic failure and even death. Despite the remarkable advancement in the treatment of chronic hepatitis B over the past decade, proper strategies for the prevention and management of HBV reactivation remain elusive. Moreover, with the increasing use of rituximab in patients with lymphoma, HBV reactivation in occult or past infections has become increasingly problematic, especially in HBV-endemic regions. This review addresses the current knowledge on the clinical aspects and management of chemotherapy-related HBV reactivation, updates from recent reports, several unresolved issues and future perspectives.

High-throughput and sensitive next-generation droplet digital PCR assay for the quantitation of the hepatitis C virus mutation at core amino acid 70

The next-generation droplet digital polymerase chain reaction (ddPCR) assay employs an emulsion-based endpoint to quantitate the amount of target DNA and is more robust than real-time PCR when analyzing sequence variations. However, no studies have applied this technique to quantitate mutations in polymorphic viral genomes. To develop this approach, a ddPCR-based assay was designed to quantitate with high-throughput and sensitivity mutations and their frequencies in codon 70 of the hepatitis C virus (HCV) gene that encodes the Core protein. The assay was linear from 2.5 to 10(5) copies per assay, and the limit of detection of mutants in the presence of a 20,000-fold excess of wild type was 0.005%. The results correlated well with those obtained using the COBAS(®) TaqMan(®) HCV Test, which is a real-time PCR assay for the quantitative detection of HCV RNA in human serum (n=87; range, 2.3-7.7log10IU/mL; Pearson's R(2)=0.9120; p<0.0001). The median frequencies of mutations by ddPCR were 0.262% (n=55; range, 0-37.951%) and 99.687% (n=32; range, 52.191-100%) for the wild-type and mutant sequences, respectively, by direct sequencing. The ddPCR assay should be useful for quantitating mutations in other polymorphic viral genomes.

Immunosuppression in Patients with Chronic Hepatitis B

After hepatitis B virus (HBV) infection, HBV DNA persists in minute amounts in hepatocyte nuclei even in individuals with “resolved” infection. Viral replication and development of liver disease depend on the balance between viral mechanisms promoting persistence and host immune control. Patients with active or inactive disease or resolved HBV infection are at risk for reactivation with immunosuppressive therapy use. HBV reactivation varies from a clinically asymptomatic condition to one associated with acute liver failure and death. We review recent studies on HBV reactivation during immunomodulatory therapies for oncologic, gastroenterological, rheumatic, and dermatologic disorders. Risk calculation should be determined through HBV screening and assessment of immunosuppressive therapy potency. We also discuss monitoring for reactivation, prophylactic antiviral therapy, and treatment of reactivation. Prophylactic antiviral treatment is needed for all HBsAg carriers and selected patients who have anti-HBc without HBsAg and is critical for preventing viral reactivation and improving outcomes.

HBV-related events after allogeneic hematopoetic stem cell transplantatıon in a center from Turkey

To investigate the frequency of hepatitis B virus (HBV)-related events after allogeneic HCT in a moderate endemic area for HBV infection. The data of 197 patients who underwent allogeneic hematopoetic stem cell transplatation (HCT) from September 2003 through December 2010 were reviewed retrospectively with respect to HBV-related events. Resolved HBV infection was described as negative HBsAg, positive HBcAb, and positive HBsAb. Latent HBV infection was defined in patients with HBcAb positivity in the abscence of HBV DNA and HBsAb. Hepatitis B naive patients are defined as the patiens with no serological or molecular marker related to HBV. Seropositive patients were the patients with positive HBsAg and HBV-DNA. Median age was 28 (range, 15-64) years, with 128 male and 69 female patients. Median follow-up of the cohort was 8 (range, 0.5-78) months. We detected HBV-related events in 7 (3.6 %) recipients after allogeneic HCT. Five (71.4 %) of these events were HBV reactivation, while two cases (28.6 %) had acute hepatitis B infection. Four of the five reactivations were in the seropositive group (80 %), while one ocurred in a patient with resolved hepatitis. Two patients who developed acute hepatitis B were HBV naive and previously immunized patients, respectively. Hepatitis B virus reactivation remains a problem in seropositive patients and might require more effective treatment strategies.

Hepatitis B virus management to prevent reactivation after chemotherapy: a review

PURPOSE

Reactivation of hepatitis B virus (HBV) infection after chemotherapy can lead to liver failure and death. Conflicting recommendations regarding HBV screening in cancer patients awaiting chemotherapy mean that some patients at risk for HBV reactivation are not being identified and treated with prophylactic antiviral therapy.

METHODS

We performed a narrative review of the existing evidence regarding screening for and management of HBV infection among patients with cancer using Ovid Medline, PubMed, and the Cochrane Library.

RESULTS

Our review showed inconsistencies in the definition and management strategies for HBV reactivation. The timeframe of reactivation is variable, and its molecular mechanisms are not clear. There are five effective antiviral agents that can be used as prophylaxis to prevent reactivation of HBV infection in cancer patients; however, the optimal drug and duration of therapy are unknown. Reactivation is more commonly reported in patients with hematologic malignancies receiving rituximab treatment, but reactivation can occur after other chemotherapies and in patients with solid tumors. Screening with all three screening tests-HBsAg, anti-HBc, and anti-HBs-allows the most thorough interpretation of a patient's serologic profile and assessment of reactivation risk; however, decision-making and cost-effectiveness studies are needed to determine optimal screening strategies.

CONCLUSIONS

Prevention of reactivation of HBV infection depends on identification of patients at risk and initiation of antiviral prophylaxis, but data to guide screening and treatment strategies are lacking. Additional research is necessary to accurately define and predict reactivation, identify best antiviral treatment strategies, and identify cost-effective HBV screening strategies.

KASL Clinical Practice Guidelines: Management of chronic hepatitis B

The guideline on the management of chronic hepatitis B (CHB) was first developed in 2004 and revised in 2007 by the Korean Association for the Study of the Liver (KASL). Since then there have been many developments, including the introduction of new antiviral agents and the publications of many novel research results from both Korea and other countries. In particular, a large amount of knowledge on antiviral resistance--which is a serious issue in Korea--has accumulated, which has led to new strategies being suggested. This prompted the new guideline discussed herein to be developed based on recent evidence and expert opinion.

TARGET POPULATION

The main targets of this guideline comprise patients who are newly diagnosed with CHB and those who are followed or treated for known CHB. This guideline is also intended to provide guidance for the management of patients under the following special circumstances: malignancy, transplantation, dialysis, coinfection with other viruses, pregnancy, and children.

Chronic hepatitis B infection

The management of chronic hepatitis B virus (HBV) infection requires understanding the natural history of the disease as well as the risks, benefits, and limitations of the therapeutic options. This article covers the principles governing when to start antiviral therapy, discusses recent advances using hepatitis B surface antigen quantification to better define various phases of infection, describes the use of HBV core, precore, and viral genotyping as well as host IL28B genotyping to predict response to interferon therapy, and reports on the management of HBV in 3 special populations (pregnancy, postliver transplantation, and in the setting of chemotherapy or immunosuppression).

Detection of HBV genotypes of tumor tissues and serum by a fluorescence polarization assay in north-western China's hepatocellular carcinoma patients

BACKGROUND

The understanding of the distribution of hepatitis B virus genotypes and the occult hepatitis B virus infection in hepatocellular carcinoma may shed light into the prevention and treatment of hepatocellular carcinoma. The purpose of the study is to investigate hepatitis B virus genotypes distribution, the high-risk genotypes and the occult infection in north-western China's hepatocellular carcinoma patients.

METHODS

Hepatitis B virus genotypes A-D of hepatocellular carcinoma tumor tissues and serum samples in 268 north-western China hepatocellular carcinoma patients were detected by fluorescence polarization assay. The hepatitis B virus genotypes in serum and matched primary tumor tissue samples were compared. Hepatitis B surface antigen and α-fetoprotein in serum were detected. Occult hepatitis B virus infections were analyzed. The relationship between hepatitis B virus genotypes and clinicopathologic characteristics were analyzed statistically using SPSS v.10.0.

RESULTS

Intrahepatic hepatitis B virus DNA was detected in 83.6% of 268 patients, whereas serum hepatitis B virus DNA was detected in 78.7%. The hepatitis B virus genotypes in serum were consistent with the results in matched tumor tissue. Intrahepatic hepatitis B virus genotype B and C were detected respectively in 11.6% and 54.5% of the patients. Mixed intrahepatic hepatitis B virus genotypes were detected in 13.4% of 268 patients. There was not mixed hepatitis B virus infection in Edmondonson grade I. The patients with mixed HBV genotypes exhibited statistically significant different Edmondson grade than the patients with single type HBV infection (p < 0.05). Hepatitis B surface antigens were positive in 77.2% of 268 patients. Hepatitis B virus genotype C was detected in 64.7% of occult infected patients. There was no significant differences of patients' ages and α-fetoprotein level in different groups of intrahepatic hepatitis B virus genotypes (p > 0.05).

CONCLUSIONS

Hepatitis B virus genotype C was associated closely with the development of hepatocellular carcinoma and the occult hepatitis B virus infection in patients in north-western China. There was a relatively high prevalence of mixed hepatitis B virus infection in Edmondonson grade III-IV.

Hepatitis B Reactivation in a HBsAg-Negative, HBcAb-Positive Patient Receiving Fludarabine for the Treatment of Chronic Lymphocytic Leukaemia

Hepatitis B virus (HBV) reactivation is an increasingly recognized cause of morbidity and mortality in patients undergoing chemotherapy. In haematology, the risk of reactivation of B hepatitis among HBsAg-positive patients has been documented; therefore, use of lamivudine prophylaxis is recommended before starting chemotherapy. Differently, for HBsAg-negative patients with markers of previous HBV infection (i.e., presence of isolated anti-HBc positivity) (anticore patients) management strategies are not univocal. We describe a rare case of HBV reactivation in an anticore patient after fludarabine therapy for chronic lymphocytic leukaemia. The patient fully recovered after a 6-month course of lamivudine with persistent HBV-DNA clearance and loss of HBsAg. The most important feature of this case is that fludarabine alone infrequently determines HBV reactivation, especially in anticore patients. Therefore, we suggest that patients candidates to receive fludarabine therapy should be considered for lamivudine prophylaxis, not only if HBsAg-positive, but even if anticore-positive only.

A mathematical model of the intracellular replication and within host evolution of hepatitis type B virus: Understanding the long time course of chronic hepatitis

Hepatitis B virus (HBV) causes acute and chronic liver disease. Especially, chronic hepatitis is a major risk factor of liver cirrhosis and hepatocellular carcinoma. Viral kinetics of HBV observed in peripheral blood is quite different depending on the clinical course of hepatitis. But the relationship between the intracellular replication dynamics and clinical course of HBV infection is unclear. Further it is very difficult to predict the long time course of hepatitis because the nature of HBV is changed by mutation within host with high mutation rate. We investigate the intracellular replication dynamics and within host evolution of HBV by using a mathematical model. Two different intracellular replication patterns of HBV, "explosive" and "arrested", are switched depending on the viral gene expression pattern. In the explosive replication, prominent growth of HBV is observed. On the other hand, the virion production is restricted in the arrested replication. It is suggested that the arrested and explosive replication is associated with chronic hepatitis and exacerbation of hepatitis respectively. It is shown by our evolutionary simulation that the exacerbation of hepatitis is caused by the emergence of explosive genotype of HBV from arrested genotype by mutation during chronic hepatitis. It is also shown that chronic infection without exacerbation is maintained by short waiting time for virion release and superinfection with arrested genotype. It is suggested that extension of waiting time for virion release and existence of uninfected hepatocyte in the liver may become risk factors for the exacerbation of hepatitis.

Clinical and virological factors associated with hepatitis B virus reactivation in HBsAg-negative and anti-HBc antibodies-positive patients undergoing chemotherapy and/or autologous stem cell transplantation for cancer

We studied clinical outcome and clinico-virological factors associated with hepatitis B virus reactivation (HBV-R) following cancer treatment in hepatitis B virus surface antigen (HBsAg)-negative/anti-hepatitis B core antibodies (anti-HBcAb)-positive patients. Between 11/2003 and 12/2005, HBV-R occurred in 7/84 HBsAg-negative/anti-HBcAb-positive patients treated for haematological or solid cancer. Virological factors including HBV genotype, core promoter, precore, and HBsAg genotypic and amino acid (aa) patterns were studied. Patients presenting with reactivation were men, had an hepatitis B virus surface antibody (HBsAb) titre <100 IU/L and underwent >1 line of chemotherapy (CT) significantly more frequently than controls. All were treated for haematological cancer, 3/7 received haematopoietic stem cell transplantation (HSCT), and 4/7 received rituximab. Using multivariate analysis, receiving >1 line of CT was an independent risk factor for HBV-R. Fatal outcome occurred in 3/7 patients (despite lamivudine therapy in two), whereas 2/4 survivors had an HBsAg seroconversion. HBV-R involved non-A HBV genotypes and core promoter and/or precore HBV mutants in all cases. Mutations known to impair HBsAg antigenicity were detected in HBV DNA from all seven patients. HBV DNA could be retrospectively detected in two patients prior cancer treatment and despite HBsAg negativity. HBV-R is a concern in HBsAg-negative/anti-HBcAb-positive patients undergoing cancer therapy, especially in males presenting with haematological cancer, a low anti-HBsAb titre and more than one chemotherapeutic agent. HBV DNA testing is mandatory to improve diagnosis and management of HBV-R in these patients. The role of specific therapies such as rituximab or HSCT as well as of HBV aa variability deserves further studies.

HBV reactivation after fludarabine chemotherapy identified on investigation of suspected transfusion-transmitted Hepatitis B virus

BACKGROUND & AIMS

Multi-transfused patients often receive treatments inducing various levels of immunodeficiency. Acute viral infections may then be attributed either to transfusion-transmitted infection (TTI) or reactivation of a past infection.

METHODS

A patient with chronic lymphocytic leukemia (CLL) who had >250 blood donor exposures developed acute Hepatitis B virus (HBV) infection. Routine donor testing for HB core antibodies (anti-HBc) was in place in the relevant period and investigations undertaken on the blood donors were negative.

RESULTS

Review of historical, molecular, and antigenic evidence demonstrated reactivation of a recovered HBV infection dating >30 years and the selection of a rare escape mutant that briefly replicated and caused acute liver disease. This mutant was unreactive with several HBsAg assays and poorly reactive with an HBV vaccine plasma. Correcting the C139Y substitution by site directed mutagenesis of recombinant surface proteins re-established assay reactivity.

CONCLUSIONS

Fludarabine, but not Chlorambucil, appeared sufficiently immunosuppressive to trigger reactivation despite low levels of neutralizing antibodies. Differentiating between TTI and reactivation of HBV becomes more challenging with the increasing frequency of immunocompromised blood recipients. Chemotherapy with Fludarabine alone should be considered as carrying high risk of viral reactivation. Pre-treatment testing and peripheral blood sample archiving may be indicated in HBsAg negative patients.

How I treat and monitor viral hepatitis B infection in patients receiving intensive immunosuppressive therapies or undergoing hematopoietic stem cell transplantation

Hepatitis B virus (HBV) reactivation is a serious but preventable complication of immunosuppression. Full HBV serologic profile must be obtained from all patients receiving intensive immunosuppressive therapy. In general, preemptive anti-HBV therapy is more effective than giving treatment after development of reactivation. Prompt lamivudine therapy should be given to at-risk patients who are hepatitis B surface antigen (HBsAg)-positive. It is recommended that lamivudine be continued until at least 6 months after the cessation of immunosuppression. Some patients requiring a longer duration of lamivudine therapy are at risk of developing drug resistance. The newer anti-HBV agents are effective in overcoming lamivudine resistance. Early use of these agents may be considered. HBV reactivation was observed in HBsAg-negative patients with occult HBV infection (HBV DNA-positive) who are on heavy immunosuppression. The optimal management of this group of patients is unclear. For patients receiving allogeneic HSC transplants, the HBV status of the donors requires special attention. To minimize the risk of transmission of infection to recipients, HBsAg-positive donors should receive adequate anti-HBV therapy before HSC donation. As the result of adoptive immune transfer, clearance of HBsAg is observed in HBsAg-positive patients receiving HSC transplants from donors who are positive for hepatitis B surface and core antibodies.

Molecular characterization of a variant virus that caused de novo hepatitis B without elevation of hepatitis B surface antigen after chemotherapy with rituximab

Hepatitis B virus (HBV) reactivation in hepatitis B surface antigen (HBsAg)-negative patients following treatment with rituximab has been reported increasingly. The aim of this study was to investigate the molecular mechanisms underlying HBV reactivation in an HBsAg-negative patient. HBV was reactivated in a 75-year-old man following chemotherapy with rituximab, without elevation of HBsAg. The patient's full-length HBV genome was cloned and the entire sequence was determined. Transfection studies were performed in vitro using recombinant wild-type HBV (wild-type), the patient's HBV (patient), and two chimeric HBV constructs, in which the preS/S region of the patient and wild-type virus had been exchanged with one another. Secreted HBsAg and intra- and extra-cellular HBV DNA were measured. The number of amino acid substitutions in HBV from this patient was much higher than in previous reports of HBV mutants, such as occult HBV and vaccine escape HBV mutants. Levels of HBsAg and HBV DNA production in vitro were significantly lower in the patient compared to wild-type transfections. From analyses of the chimeric constructs, the altered preS/S region was responsible mainly for this impairment. These results show that highly mutated HBV can reactivate after chemotherapy with rituximab, despite an unusually large number of mutations, resulting in impaired viral replication in vitro. Severe immune suppression, probably caused by rituximab, may permit reactivation of highly mutated HBV. These findings have important clinical implications for the prevention and management of HBV reactivation and may explain partially the mechanism of recent, unusual cases of HBV reactivation.

[Management of hepatitis B virus reactivation during chemotherapy or immunosuppressive therapy]

Reactivation of viral hepatitis B is a well-known complication in patients receiving chemotherapy or immunosuppressive therapy; its incidence reaches 50%. This reactivation is associated with a high rate of morbidity and mortality. Prophylactic treatment of viral reactivation with lamivudine resulted in lowering the incidence of this risk and improving prognosis in recent studies. Patients with hematological malignancies and other cancers require a precise assessment of their hepatitis B status and adequate management. There is not yet a consensus about the appropriateness of prophylactic treatment of occult hepatitis B infection or of pretreatment virologic assessment, especially measurement of viral DNA.

Multicenter study of a new fully automated HBsAg screening assay with enhanced sensitivity for the detection of HBV mutants

In a multicenter study a new, fully automated Roche Diagnostics Elecsys HBsAg II screening assay with improved sensitivity to HBsAg mutant detection was compared to well-established HBsAg tests: AxSYM HBsAg V2 (Abbott), Architect HBsAg (Abbott), Advia Centaur HBsAg (Bayer) Enzygnost HBsAg 5.0 (Dade-Behring), and Vitros Eci HBsAg (Ortho). A total of 16 seroconversion panels, samples of 60 HBsAg native mutants, and 31 HBsAg recombinant mutants, dilution series of NIBSC and PEI standards, 156 HBV positive samples comprising genotypes A to G, 686 preselected HBsAg positive samples from different stages of infection, 3,593 samples from daily routine, and 6,360 unselected blood donations were tested to evaluate the analytical and clinical sensitivity, the detection of mutants, and the specificity of the new assay. Elecsys HBsAg II showed a statistically significant better sensitivity in seroconversion panels to the compared tests. Fifty-seven out of 60 native mutants and all recombinant mutants were found positive. Among 156 HBV samples with different genotypes and 696 preselected HBsAg positive samples Elecsys HBsAg II achieved a sensitivity of 100%. The lower detection limit for NIBSC standard was calculated to be 0.025 IU/ml and for the PEI standards ad and ay it was <0.001 and <0.005 U/ml, respectively. Within 2,724 daily routine specimens and 6.360 unselected blood donations Elecsys HBsAg II showed a specificity of 99.97 and 99.88%, respectively. In conclusion the new Elecsys HBsAg II shows a high sensitivity for the detection of all stages of HBV infection and HBsAg mutants paired together with a high specificity in blood donors, daily routine samples, and potentially interfering sera.

The safety profile of cyclophosphamide in multiple sclerosis therapy

Cyclophosphamide (Cyc) is an alkylating agent used to treat malignancies and autoimmune diseases, such as lupus nephritis, rheumatoid arthritis and immune-mediated neuropathies. Over the past 40 years, Cyc has also been applied to treat multiple sclerosis (MS) and the effective stabilisation of rapidly progressive forms of MS has been demonstrated in several studies. Cyc has a dose-dependent bimodal effect on the immune system. High doses have been demonstrated to induce an anti-inflammatory immune deviation (i.e., suppression of T helper 1 and enhancement of T helper 2 activity), affect CD4CD25(high) regulatory T cells and establish a state of marked immunosuppression. Data from the literature suggest that Cyc is particularly indicated in the treatment of young MS patients, suffering from a very active inflammatory disease characterised by frequent relapses and rapid accumulation of disability and displaying gadolinium-enhancing lesions on brain magnetic resonance. The most common Cyc-based therapeutic protocol applied in MS consists of monthly intravenous pulses for 1 year followed by bimonthly pulses for the second year, with or without prior infusion of corticosteroids. This protocol is usually well tolerated by the patients. Indeed, most of the side effects (mild alopecia, nausea and vomiting, cystitis) are dose dependent, transient and completely reversible. Definitive amenorrhoea is observed only in older female patients (aged > 40 years). Cyc has a safety and efficacy profile similar to that of mitoxantrone and can be used in patients whose disease is not controlled by IFN-beta or glatiramer acetate. Short course (6-12 months) of Cyc therapy can precede the initiation of immunomodulatory treatment in selected patients with an aggressive MS onset.