Levels of viraemia in subjects with serological markers of past or chronic hepatitis B virus infection

Prediagnostic serum organochlorine insecticide concentrations and primary liver cancer: A case-control study nested within two prospective cohorts

Although experimental evidence indicates that certain organochlorine insecticides are hepatocarcinogens, epidemiologic evidence for most of these chemicals is very limited. We estimated associations, using prospectively collected sera, between organochlorine insecticide concentrations and cancer registry-identified primary liver cancer in two cohorts, one from the United States and one from Norway. In nested case-control studies, we used sera collected in the 1960s-1980s from 136 cases and 408 matched controls from the Kaiser Permanente Northern California Multiphasic Health Checkup (MHC) cohort and 84 cases and 252 matched controls from the population-based Norwegian Janus cohort. We measured concentrations of nine organochlorine insecticides/metabolites and markers of hepatitis B and C in sera. Adjusted odds ratios (OR) and 95% confidence intervals (CI) for tertiles of lipid-corrected organochlorines were calculated for each cohort using conditional logistic regression. Among MHC participants with sera from the 1960s, there was a suggestive exposure-response trend for trans-nonachlor (second and third tertile of analyte ORs = 1.63 and 1.95, respectively; p-trend = 0.08) and a nonsignificantly elevated risk for the highest tertile of oxychlordane (OR = 1.87). Among Janus participants with sera from the 1970s, we observed an apparent trend for p,p'-DDT (second and third tertile ORs = 1.70 and 2.14, respectively; p-trend = 0.15). We observed little consistency in patterns of association between the cohorts. We found limited evidence that exposure to p,p'-DDT and chlordane-related oxychlordane and trans-nonachlor may be associated with increased risk of primary liver cancer. However, the modest strength of these associations and their lack of concordance between cohorts necessitate caution in their interpretation.

Are current screening protocols for chronic hepatitis B virus infection adequate?

Chronic hepatitis B virus (HBV) infection screening usually includes only HBV surface antigen (HBsAg) testing; HBV core and surface antibody (anti-HBc, anti-HBs) assays, indicating resolved infection and immunity, are not routinely performed. Yet, serum HBV DNA is measurable in approximately 10% of HBsAg-negative/anti-HBc-positive cases, representing occult HBV infection (OBI). Patient blood samples from 2 Veterans Affairs medical center look-back investigations were screened for HBV infection using HBsAg enzyme immunoassays. Supplementary testing included anti-HBc and anti-HBs enzyme immunoassays. For anti-HBc-positive samples, HBV DNA testing was performed. Background OBI prevalence was further estimated at these 2 facilities based on HBV serology testing results from 1999-2012. Finally, a literature review was performed to determine OBI prevalence in the published literature. Of 1887 HBsAg-negative cohort patients, 98 (5.2%) were anti-HBc positive/anti-HBs negative; and 175 (9.3%), anti-HBc positive/anti-HBs positive. Six of 273 were HBV DNA positive, representing 0.3% of the total tested and 2.2% who were anti-HBc positive/anti-HBs negative or anti-HBc positive/anti-HBs positive. Among 32,229 general population veterans at these 2 sites who had any HBV testing, 4/108 (3.7%) were HBV DNA positive, none of whom were part of the cohort. In 129 publications with HBsAg-negative patients, 1817/1,209,426 (0.15%) had OBI. However, excluding blood bank studies with greater than 1000 patients, the OBI rate increased to 1800/17,893 (10%). OBI is not rare and has implications for transmission and disease detection. HBsAg testing alone is insufficient for detecting all chronic HBV infections. These findings may impact blood donation, patient HBV screening, follow-up protocols for patients assumed to have cleared the infection, and initiation of immunosuppression in patients with distant or undetected HBV.

Hepatitis B core antibody-positive donors in cardiac transplantation: a single-center experience

Hepatitis B virus (HBV) core antibody (HBcAb)-positive donors are increasingly utilized in solid organ transplantation. We report a single center's experience in cardiac transplantation with 18 HBcAb-positive donors. Available follow-up on recipients of cardiac allografts from HBcAb-positive donors, including 2 donors with low-level serum HBV DNA at the time of transplantation, demonstrated no documented donor-derived HBV transmission.

[Occult hepatitis B virus infection in chronic hepatitis C]

Occult HBV infection is defined as the presence of HBV DNA in the liver (with or without detectable or undetectable HBV DNA in the serum) of individuals testing negative for HBsAg. Studies on occult HBV infection in hepatitis C patients have reported highly variable prevalence, because the prevalence of occult HBV infection varies depending on the hepatitis B risk factors and methodological approaches. The most reliable diagnostic approach for detecting occult HBV detection is through examination of liver DNA extracts. HCV has been suspected to strongly suppress HBV replication up to the point where it may be directly responsible for occult HBV infection development. However, more data are needed to arrive at a definitive conclusion regarding the role of HCV in inducing occult HBV infection. Occult HBV infection in chronic hepatitis C patients is a complex biological entity with possible relevant clinical implications. Influence of occult HBV infection on the clinical outcomes of chronic hepatitis C may be considered negative. However, recent studies have shown that occult HBV infection could be associated with the development of hepatocellular carcinoma and contribute to the worsening of the course of chronic liver disease over time in chronic hepatitis C patients. Nevertheless, the possible role of occult HBV infection in chronic hepatitis C is still unresolved and no firm conclusion has been made up until now. It still remains unclear how occult HBV infection affects the treatment of chronic hepatitis C. Therefore, in order to resolve current controversies and understand the pathogenic role and clinical impacts of occult HBV infection in chronic hepatitis C patients, well-designed clinical studies are needed.

Clinical significance of occult hepatitis B virus infection in chronic hepatitis C patients

Background/Aims

We investigated the frequency of occult hepatitis B virus (HBV) infection in anti-hepatitis C virus (HCV)-positive individuals and the effects of occult HBV infection on the severity of liver disease.

Methods

Seventy-one hepatitis B virus surface-antigen (HBsAg)-negative patients were divided according to their HBV serological status into groups A (anti-HBc positive, anti-HBs negative; n=18), B (anti-HBc positive, anti-HBs positive; n=34), and C (anti-HBc negative, anti-HBs positive/negative; n=19), and by anti-HCV positivity (anti-HCV positive; n=32 vs. anti-HCV negative; n=39). Liver biopsy samples were taken, and HBV DNA was quantified by real-time PCR.

Results

Intrahepatic HBV DNA was detected in 32.4% (23/71) of the entire cohort, and HBV DNA levels were invariably low in the different groups. Occult HBV infection was detected more frequently in the anti-HBc-positive patients. Intrahepatic HBV DNA was detected in 28.1% (9/32) of the anti-HCV-positive and 35.9% (14/39) of the anti-HCV-negative subjects. The HCV genotype did not affect the detection rate of intrahepatic HBV DNA. In anti-HCV-positive cases, occult HBV infection did not affect liver disease severity.

Conclusions

Low levels of intrahepatic HBV DNA were detected frequently in both HBsAg-negative and anti-HCV-positive cases. However, the frequency of occult HBV infection was not affected by the presence of hepatitis C, and occult HBV infection did not have a significant effect on the disease severity of hepatitis C.

Long-term outcome of patients with lamivudine after early cessation of hepatitis B immunoglobulin for prevention of recurrent hepatitis B following liver transplantation

BACKGROUND

The aim of this study is to examine the efficacy of long-term prophylaxis with lamivudine (LAM) after a course of post-operative hepatitis B immunoglobulin (HBIG) in patients who underwent liver transplantation (LT) for hepatitis B virus (HBV)-related disease.

RESULT

The medical records of HBV-infected patients who underwent a LT in our institution between July 2001 and May 2005 were reviewed. There were 15 liver transplant recipients who were administered HBIG for <18 months and used LAM as a maintenance prophylaxis regime enrolled in this study. At enrollment, all patients were hepatitis B surface antigen (HBsAg) positive and three patients were HBeAg positive. There were 13 patients who were HBV DNA positive with a mean viral load of 5.4 log copies/mL, and among them, 12 recipients were on antiviral therapy with LAM (100 mg/d orally) for 12-168 d, resulting in HBV DNA negative levels in nine patients prior to their transplant. HBV recurrence post-LT was noted in two patients who had very high-HBV DNA levels pre-LT. Both of these patients showed LAM-resistant mutation at the time of recurrence. The 11 patients who were HBV DNA negative before LT (low-risk patients) had no HBV recurrence during a follow-up at a median of 58 months post-LT. This included five patients who had intermittent low-level HBV DNA post-LT (HBsAg negative), of whom two had YMDD mutation and these two were given adefovir in addition to LAM.

CONCLUSION

Our retrospective study demonstrated excellent long-term outcomes in the low-risk patients treated with LAM after a short course of HBIG.

The underlying mechanisms for the 'anti-HBc alone' serological profile

The serological pattern, "anti-HBc alone", characterized by the presence of antibodies against the core antigen of hepatitis B virus (anti-HBc) as the only marker of hepatitis B, is not rare in a diagnostic setting. Depending on the prevalence of HBV infection and the patient group investigated, 1-31% of positive anti-HBc results are isolated positive findings. Anti-HBc alone is frequently observed in intravenous drug addicts, HIV-infected individuals, patients who are coinfected with HBV and hepatitis C virus, and pregnant women. However, it is not clear how this profile should be interpreted. Several studies have shown that anti-HBc alone is not only compatible with acute and resolved HBV infection but also with chronic infection. The reasons for the lack of HBsAg and anti-HBs in anti-HBc-alone individuals are not clear, but several mechanisms and possibilities have been suggested that could explain this phenomenon, some of which are delineated in this article.

Lower baseline ALT cut-off values and HBV DNA levels better differentiate HBeAg(-) chronic hepatitis B patients from inactive chronic carriers

AIM: To determine whether new cut-off values for alanine aminotransferase (ALT) and baseline hepatitis B virus (HBV) DNA levels better differentiate HBeAg(-) chronic hepatitis B (CHB) patients from inactive chronic carriers.

METHODS: Ninety-one patients [32 HBeAg(+) CHB, 19 inactive carriers and 40 HBeAg(-) CHB] were followed up for 2 years and were tested for HBV DNA levels by a PCR-based assay. ALT was tested twice during the last 6 mo using new cut-off values: ULN (upper limit of normal) 30 IU/L for males, 19 IU/L for females. Diagnostic accuracy, sensitivity, specificity, positive and negative predictive values were calculated by discriminant analysis.

RESULTS: When using the revised ALT cut-off values, the lowest optimal HBV DNA level that differentiated HBeAg(-) CHB patients from inactive carriers was 50 000 copies/mL. The diagnostic accuracy of HBV DNA to determine inactive carriers with a cut-off of 50 000 copies/mL was similar to the previously recommended cut-off of 100 000 copies/mL (91%). HBV DNA levels were lower than the cut-off value in 95% of inactive carriers and in 28% of HBeAg(-) CHB patients. With ALT < 30 IU/L in men and < 19 IU/L in women and HBV DNA levels < 100 000 copies/mL, the risk of CHB is 5%. On the other hand, if ALT values were > 30 IU in men and > 19 IU in women and baseline HBV DNA levels were > 100 000 copies/mL, the risk is 86%.

CONCLUSION: New cut-off values for ALT together with HBV DNA levels proposed by AASLD (American Association for the Study of Liver Diseases) and NIH (National Institute of Health) consensus seem appropriate to characterize inactive carriers.

Anti-HBc screening in Egyptian blood donors reduces the risk of hepatitis B virus transmission

Occult hepatitis B virus (HBV) in blood donors is considered as a potential risk for transmission of HBV infection. The aim of this study was to determine the prevalence of anti-hepatitis B core antibody (anti-HBC) positivity in Egyptian blood donations as well as to estimate the frequency of HBV-DNA in anti-HBc-positive donations. The study included 760 Egyptian healthy blood donors, representing 26 different Egyptian governorates screened according to routine practice for the presence of hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibodies (Abs), HIV-1/2 Abs and Treponema Abs. The accepted blood units for donation were tested for the presence of total anti-HBc Abs by two tests. Positive units for anti-HBc were further tested for HBV-DNA by polymerase chain reaction. According to routine screening, a total of 48/760 units (6.3%) were rejected [38 (5%) HCV-Ab-positive units, 9 (1.18%) HbsAg-positive units and 1 (0.13%) Treponema-Ab-positive unit]. Among the accepted blood units for donation, prevalence of anti-HBc was 78/712 units (10.96%). HBV-DNA was detected in 9/78 (11.54%) of the anti-HBc-positive units, and thus, occult HBV infection was detected in 9/712 (1.26%) of the accepted blood donations. Implementing anti-HBc test to the routine assay for the forthcoming two decades would certainly eliminate possible HBV-infected units. Rejection of these units will be beneficial to decrease the risk of HBV transmission with its potential consequences particularly in immunocompromised recipients.

The evaluation of immune responses to hepatitis B vaccination in diabetic and non-diabetic haemodialysis patients and the use of tetanus toxoid

AIM

The aim of this study was to investigate whether haemodialysis (HD) patients suffering from diabetes mellitus could be considered at risk for the development of the protective antibodies to hepatitis B (HB) vaccination and, to evaluate the effectiveness of tetanus toxoid (TT) administrated 2 days before HB vaccination.

METHODS

Forty-nine HD patients were divided into two groups: group A (19 diabetic patients) and group B (30 non-diabetic patients). A dose of 40 microg recombinant HB vaccine was injected intramuscularly to the patients at 0, 1, 2 and 6 months.

RESULTS

After the completion of the course, the patients in group A were found to have a lower protective antibody rates than the patients in group B (57.8% vs 70%) (P > 0.05). After the administration of additional booster doses during 12 months, the protective antibody to hepatitis B surface antigen (HBsAb) levels were detected in 78.9% and 96.6% of the patients in group A and group B, respectively (P > 0.05). The patients not having protective HBsAb levels were administered TT and HB vaccines, and after course, all of them have produced protective HBsAb levels.

CONCLUSION

The present study showed that diabetic patients on HD may carry a greater risk of not seroconverting than non-diabetic ones for antibody response to HB vaccination. The use of TT 2 days before HB vaccination may be a useful and effective method of enhancing the immune response to HB vaccination, especially in the patients with diabetes mellitus on HD.

Molecular testing in the diagnosis and management of chronic hepatitis B

Hepatitis B virus (HBV) is an enveloped virus with a small (3.2-kb) partially double-stranded DNA genome that causes acute and chronic infections. The impact of these infections on public health worldwide is enormous, with an estimated prevalence of 2 billion acute infections and 360 million chronic infections globally. This review focuses on chronic hepatitis B and the molecular assays used in its diagnosis and management. Background information, including that about features of the hepatitis B virion, viral replication, and epidemiology of infection, that is important for understanding chronic hepatitis B and molecular diagnostic tests for HBV is provided. To facilitate an understanding of the utility of molecular testing for chronic hepatitis B, the four stages of chronic hepatitis B infection that are currently recognized, as well as an additional entity, occult hepatitis B, that can be diagnosed only by sensitive nucleic acid amplification methods, are reviewed in detail, including available therapeutic agents. The molecular diagnostic content focuses on tests for HBV DNA quantification, genotyping, and mutation detection (including precore/core promoter and antiviral resistance mutations). The discussion of these tests encompasses their current utility and performance characteristics, drawing from current clinical guidelines and other studies from the literature. In recognition of the continual evolution of this field, the final section describes emerging molecular markers with future diagnostic potential.

Hepatitis B virus and HIV coinfection: relationship of different serological patterns to survival and liver disease

OBJECTIVES

Eighty per cent of HIV-positive patients show evidence of past or current infection with hepatitis B virus (HBV). The impact of chronic HBV infection or the presence of isolated HBV core antibody on survival in the era of highly active antiretroviral therapy (HAART) has not been well studied.

METHODS

This retrospective analysis included patients from the HIV Atlanta Veterans Affairs Cohort Study (HAVACS). This cohort comprises 2818 HIV-positive patients followed since 1982. For this analysis, 1685 patients with available HBV serologies were included, based on laboratory records available since 1992. Adjusted survival analyses were performed for patients showing any of four serological patterns for HBV: (1) surface antigen positive (chronic HBV infection), (2) isolated core antibody, (3) surface antibody with or without core antibody (resolved/vaccinated) and (4) no HBV markers (negative group). Risk factors for liver disease were identified.

RESULTS

A trend was seen for a lower survival rate from AIDS to death in the chronic HBV infection group compared with the negative group [hazard ratio (HR) 1.43; P=0.118]. The only independent predictor of lower survival rate was hepatitis C virus positivity (HR 1.62; P=0.008). Protective factors were use of HAART (HR 0.40; P=0.0003), use of lamivudine (HR 0.36; P<0.0001) and use of tenofovir (HR 0.23; P<0.0001). Survival from HIV diagnosis to death was not different among the HBV groups. Isolated core antibody patients did not have a lower survival rate compared with those with resolved HBV infection. Patients with chronic HBV infection were 3.5 times more likely to have liver disease than those with no HBV infection (P<0.02).

CONCLUSIONS

There is a trend towards a lower survival rate in patients with HIV and chronic HBV infection, but the difference did not reach statistical significance. The presence of isolated core antibody was not associated with a lower survival rate.

Low risk of hepatitis B virus recurrence after withdrawal of long-term hepatitis B immunoglobulin in patients receiving maintenance nucleos(t)ide analogue therapy

Hepatitis B virus (HBV) recurrence rates of 0-16% had been reported in patients maintained on nucleoside analogues (NA) after hepatitis B immunoglobulin (HBIG) discontinuation after orthotopic liver transplantation (OLT). However, follow-up in most studies was short. We aimed to determine the long-term risk of HBV recurrence using this strategy. All HBV patients who received > or =7 doses of intravenous HBIG after OLT, with no HBV recurrence while receiving HBIG, and who eventually discontinued HBIG and were maintained on NA, were included. HBV recurrence was defined as HBsAg-positive or HBV DNA > or =5 log copies/mL on 2 consecutive occasions. Twenty-one patients met the inclusion criteria. Immediate post-OLT prophylaxis was combination HBIG and NA in 15 patients, whereas 6 patients received HBIG monotherapy for 62-109 months before NA was added. HBIG was discontinued a median of 26 (range, 0.2-121) months after OLT. Median follow-up post-HBIG discontinuation was 40 (range, 5-51) months. Only 1 patient, who had 12 months of HBIG and was noncompliant to NA therapy, had HBV recurrence, 34 months after HBIG discontinuation. One patient had HBV DNA of 3.3 log copies/mL 47 and 48 months after HBIG discontinuation but remained HBsAg-negative. Lamivudine-resistant mutations were detected in both patients. Probability of HBV recurrence was 0% and 9% at 2 and 4 years after HBIG discontinuation. Three patients had 1-2 episodes of transiently detectable HBV DNA. All were HBV DNA and HBsAg negative on repeated tests over a period of 2-36 months. Maintenance therapy with NA after discontinuation of long-term HBIG therapy is associated with a low risk of HBV recurrence after OLT in compliant HBV patients.

Hepatitis B virus DNA in unusual serological profiles of hepatitis B surface antigen-positive sera

On the basis of a seroepidemiological survey of hepatitis B virus (HBV) infection conducted on 6208 random serum samples from four provinces of Thailand, we found 19 of 246 (7.7%) hepatitis B surface antigen (HBsAg)-positive samples with unusual serological constellations of HBV infection. Ten samples tested positive for HBsAg, anti-HBc (anti-hepatitis B core antibody), and anti-HBs (anti-hepatitis B surface antibody) markers (group I), 3 specimens were HBsAg and anti-HBs positive without detectable anti-HBc (group II), and the remaining 6 specimens showed only HBsAg (group III). In group I, 7 of 10 HBsAg-positive sera could be confirmed by HBsAg neutralization, yielding positive results for all samples. None of the group II sera were available in sufficient amounts for confirmation. In group III, five of six sera were confirmed by HBsAg neutralization, with four showing a positive reaction. HBV DNA was detected in 7 of 10 (70%) specimens in group I, in 1 of 3 (33.3%) specimens in group II, and in 3 of 6 (50%) specimens in group III. On the basis of HBsAg neutralization, HBV DNA was found in five of seven (71.4%) HBsAg-positive samples in group I and in three of four (75%) HBsAg-positive samples in group III, whereas the one confirmed HBsAg-negative sample in group III also remained negative for HBV DNA. Amino acid sequences were compared with those specifying the "a" determinant of the wild-type virus, particularly focusing on HBV-S protein variations between positions 110 and 160. Among 11 HBV DNA-positive sera, G145A was detected in 2 samples in group I, with the remaining samples identical to the wild-type virus. These unusual serological profiles may be due to the altered immune response of the host or to HBV variants.

Can Donors With Prior Hepatitis Be Safely Used for Heart Transplantation?

BACKGROUND

Heart transplantation represents a significant life-saving and increased quality-of-life intervention for patients with refractory cardiac failure. Successful transplantation requires continuous immunosuppression to avoid immune rejection. Unfortunately, persistent viral infections in donors may be transmitted to recipients in the process of heart transplantation. With the severe shortage of available organs and significant waiting list mortality there is a rationale for considering use of organs from donors with evidence of prior hepatitis B and/or hepatitis C infection.

METHODS

Published literature articles were searched using Medline, PaperChase and further review of references in relevant articles on issues related to hepatitis B and hepatitis C and heart transplantation.

RESULTS

Donor and recipient testing for hepatitis B and hepatitis C is important for relative risk assessment. Nucleic acid testing for hepatitis B DNA and hepatitis C RNA represent emerging technologies, which may add valuable information to traditional serologic testing.

CONCLUSIONS

Heart transplant recipient risk may be modified by vaccination against hepatitis B before transplantation. There is currently no available vaccine for hepatitis C. Recently described effective treatments for hepatitis B and hepatitis C provide further rationale for reconsideration of using hearts from donors with evidence of hepatitis B and/or hepatitis C infection.

Epidemiology of HBV infection in Asian blood donors: Emphasis on occult HBV infection and the role of NAT

Hepatitis B virus (HBV) infection is endemic in many Asian countries. Among many transmission routes, transfusion is the one that should be prevented. The first major success in enhancing transfusion safety came with the implementation of hepatitis B surface antigen (HBsAg) in the early 1970s. However, the studies quoted in this review demonstrate that transmission by blood components negative for HBsAg can still occur in the acute phase of infection during the seronegative window period, or during chronic stages of infection (i.c. "occult" HBV infection, OHB). OHB is defined as the presence of HBV DNA in blood or liver tissues in patients negative for HBsAg, with or without any HBV antibodies. Because of limitations in current blood screening practices, OHB is an overlooked source of HBV transmission. For policy development on screening for HBV infection in blood donors, it would be useful to assess the relative contribution of the above two sources of transfusion-transmitted HBV infection from HBsAg-negative donations. New screening policy should be evaluated on the basis of available data or newly designed studies. While anti-HBc screening can climinate residual risk of occult HBV transmission by transfusion in low-endemic areas, it would not be practical in most parts of the world where the prevalence of anti-HBc is >10% as too many otherwise healthy donors will be ineligible. On the contrary, studies mentioned in this paper indicate that nucleic acid amplification test (NAT) or new HBsAg tests of enhanced sensitivity would be effective in the screening of blood donors for OHB in highly endemic countries. However, the cost-effectiveness of blood screening tests is a major concern in Asia. We therefore have systemically reviewed the literature on prevalence and infectivity of OHB in Asian countries and the possible role of NAT for identifying blood donors in the pre-HBsAg window phase or in later stages of OHB.

Transmission of occult hepatitis B virus by transfusion to adult and pediatric recipients in Taiwan

BACKGROUND/AIMS

The infectivity of occult hepatitis B virus (HBV), defined as HBsAg-negative but HBV DNA-positive, after transfusion has been low but not negligible. To address this, we investigated the incidence of post-transfusion HBV infection after receiving screened blood units in Taiwan.

METHODS

Consecutive HBV-naïve (anti-HBc-negative) recipients with normal ALT were followed for HBV DNA and serologic markers before and after transfusion. Among 4448 blood recipients, 467 (10.5%) were anti-HBc-negative. Post-transfusion 6-month follow-up was completed for 327. We identified 5 (1.5%) who developed hepatitis B viremia 1 week after transfusion. Three were children who later seroconverted to anti-HBc but with normal ALT indicating subclinical acute infection, despite all had anti-HBs from previous vaccination. One had transient transfusion-transmitted HBV without seroconversion to anti-HBc and one possibly had occult HBV infection. Our findings suggested the possibility that occult HBV infection was transmissible by transfusion. The incidence of post-transfusion acute HBV infection was 0.9% (100 per million units) in naïve recipients in Taiwan, a figure 7 approximately 40-fold higher than in developed countries. Moreover, some vaccinated children with anti-HBs were still susceptible.

CONCLUSIONS

Therefore, despite active immunization, sensitive screening assays for occult HBV infection such as nucleic acid amplification test could be considered in endemic areas.

Evidence of occult hepatitis B virus infection among Omani blood donors: a preliminary study

OBJECTIVES

The aim of this study was to determine the prevalence of hepatitis B surface antigen (HBsAg), hepatitis B core antibodies (anti-HBc) and hepatitis B virus (HBV) DNA among a selected group of Omani blood donors.

MATERIALS AND METHODS

Two hundred HBsAg-negative donors were screened for anti-HBc. Those found to be positive were investigated for HBV DNA by polymerase chain reaction. HBsAg was retested on these sera following an immune complex dissociation technique.

RESULTS

HBsAg was present in 2.8% of the donors. Forty-one out of 200 (20.5%) HBsAg-negative donors were positive for anti-HBc. Eleven were positive for HBsAg after dissociation, whereas 8 gave readings just over the cutoff. HBV DNA was not detected in this group.

CONCLUSION

Findings indicate that testing donors for HBsAg alone is not sufficient to eliminate HBV from the blood supply in Oman.

Occult hepatitis B virus infection before and 1 year after start of HAART in HIV type 1-positive patients

Occult hepatitis B virus (HBV) infection is diagnosed when HBc antibodies and HBV-DNA are detectable in serum while hepatitis B surface antigen (HBsAg) is not. The clinical relevance of this phenomenon in HIV-1 patients starting highly active antiretroviral therapy (HAART) is unknown. We followed 93 therapy naive HIV-1-infected adults who were anti-HBc positive, HBsAg and HBeAg negative, during first year of HAART. At baseline, HBV-DNA was quantified, and HBV genotype was determined in the HBV-DNA-positive patients by sequencing a part of the HBV genome. Four of 93 patients (4%) were HBV DNA positive at baseline. All four patients tested negative for HBV-DNA after 1 year. They all received lamivudine as part of their HAART. They had no clinically significant liver enzyme elevations (LEE) during the first year of HAART. Two of the patients had a genotype A, one genotype E, and in the fourth patient sequencing was not possible. In one patient we found significant mutations in the a determinant region of HBsAg, at positions 142 and 144. In our population of therapy-naive HIV-1-infected adults who were anti-HBc positive, we found occult HBV infection in 4% of the patients. We did not find an increased risk for LEE in our population of patients after the start of HAART. Our results illustrate that occult HBV infection is more a diagnostic than a clinical problem. It may be caused by very low levels of HBV replication, concurrent presence of HBsAg and anti-HBs, or mutations in the HBsAg a determinant.

Evaluation of the COBAS amplicor HBV monitor assay and comparison with the ultrasensitive HBV hybrid capture 2 assay for quantification of hepatitis B virus DNA

Performance characteristics of the COBAS Amplicor HBV Monitor test (Roche Diagnostics), which measures hepatitis B virus (HBV) DNA quantitatively, were evaluated and compared with the Ultrasensitive HBV Hybrid Capture 2 (HC2; Digene Corporation) assay. Linearity and within-run precision were assessed for both methods by using eight HBV DNA-positive samples serially diluted to obtain a range of <100 to 500,000 HBV DNA copies/ml and run in triplicate. Agreement between the methods was studied with 100 clinical samples. HC2 assay performance near the limit of detection was investigated through repeat testing of 149 samples with HC2 and testing of 37 samples with HC2 results of <4,700 HBV DNA copies/ml by Amplicor assay and a qualitative PCR assay. The linearity experiment for Amplicor had regression of observed values compared to expected values (y = 1.073x - 0.247; R(2) = 0.993, n = 32; for HC2, y = 0.855x + 0.759, R(2) = 0.729, n = 18). Within-run standard deviation of log HBV DNA copies/ml ranged from 0.003 to 0.348 (Amplicor) and 0.027 to 0.253 (HC2). Agreement assessed by Deming regression was poor [Amplicor = 1.197(HC2) - 0.961; R(2) = 0.799, standard error of the estimate (SEE) = 0.710, n = 94]. Near the lower limit of detection, 32 of 149 repeat HC2 results were <4,700 HBV DNA copies/ml. Of the 37 samples with HC2 results of <4,700 HBV DNA copies/ml, HBV DNA was not detected in 15 samples, while HBV DNA was detected by at least one PCR method in 12 samples. Amplicor is linear from 200 to 200,000 HBV DNA copies/ml with undiluted samples, and this range can be expanded through dilution. Inconsistent HC2 results near the limit of detection justify use of a grey zone.

Occult hepatitis B virus infection in dialysis patients: a multicentre survey

BACKGROUND

The epidemiology and clinical significance of occult hepatitis B virus infection (serum hepatitis B surface antigen-negative patients with detectable hepatitis B virus viraemia in serum) remains controversial with only limited information about its prevalence in patients on long-term dialysis.

AIM

To address the epidemiology of occult HBV infection in a large cohort of dialysis patients.

METHODS

We screened a large cohort (n = 585) of Italian chronic dialysis patients; from this population, a group of hepatitis B virus surface antigen seronegative patients (n = 213) was tested by Amplicor hepatitis B virus Monitor Test to detect hepatitis B virus viraemia (hepatitis B virus-DNA) in serum.

RESULTS

Occult hepatitis B virus infection was absent (zero of 213 = 0%). Persistent hepatitis B virus surface antigen carriage was less frequent than anti-hepatitis B virus core antibody (anti-hepatitis B core antigen) seropositive status in this study group [1.88% (11 of 585) vs. 36% (216 of 585), P = 0.0001]. No dialysis patients seropositive for anti-hepatitis B core antibody in serum (zero of 123 = 0%) had detectable hepatitis B virus-DNA by polymerase chain reaction technology. No significant association between abnormal biochemical liver tests and serum anti-hepatitis B core antibody was noted in our population. Nominal logistic regression analysis demonstrated an independent and significant relationship between anti-HCV antibody and anti-hepatitis B virus core antibody in serum (Wald chi-square 16.06, P = 0.0001). The rate of seropositive patients for anti-hepatitis B virus core antibody was higher among study patients than controls with normal renal function [36.9% (216 of 585) vs. 21.4% (59 of 275), P = 0.0001]; this difference partially persisted after correction for demographic parameters, and viral markers.

CONCLUSION

In conclusion, occult hepatitis B virus was absent in our study group. Anti-hepatitis B core antibody was significantly related to presence of anti-HCV antibody supporting shared modes of transmission. Clinical studies based on molecular biology techniques provided with higher sensitivity are planned.

Biological qualification of blood units: considerations about the effects of sample's handling and storage on stability of nucleic acids

BACKGROUND

In transfusional setting introduction of nucleic amplification technique (NAT) for HBV-DNA, HCV-RNA and HIV-RNA in biological qualification of blood units suggest some problems. At first the opportunity to operate on mini-pool, at second the need to store the samples at +4 degrees C. The authors therefore have tried to estimate the impact of these conditions on the operativity of NAT testing in the transfusional setting.

METHODS

The following parameters has been estimated: distribution of viral-load in untreated subjects, stability of nucleic acids during storage at +4 degrees C, stability of nucleic acids after repeated cycles of freezing and defrosting, robustness of the test to the cross-contamination, definition of the detection-limit (95%). Quantitative tests has been performed by using the following kits: Cobas Amplicor HBV Monitor, Cobas Amplicor HCV Monitor, Cobas Amplicor HIV Monitor; the qualitative tests has been performed by using the following kits: Ampliscreen HBV, Ampliscreen HCV 2,0, Ampliscreen HIV 1,5 all supplied by Roche Molecular System (Brancburg, NJ).

RESULTS

Viral load in untreated subjects showed wide variation for HBV, HCV and HIV. HBV has been demonstrated much stable to the conservation +4 degrees C also until 168 h while for HCV and HIV a greater decrease of the viral-load was observed. For all and three virus the conservation to +4 degrees C until 72 h does not seem to involve meaningful fall in the viral-load. A remarkable reduction of the viral-load has been observed after five cycles of freezing and defrosting. All the tests showed a good robustness to cross-contamination. The detection-limit (95%) was 8 U/ml for HBV, 21 U/ml for HCV and 27 copy/ml for HIV.

CONCLUSIONS

Samples for NAT testing, can be stored until 72 h to +4 degrees C without appreciable lowering of the viral-load. Repeated cycles of changes of state should be avoided. The tests showed a good robustness to cross-contamination. NAT tests for biological qualification of blood units had a minimal sensibility around 50 (copy/unit/ml). In our experience the detection-limit (95%) was 21 U/ml for HCV, 27 copies/ml for HIV, 8 U/ml for HBV. The availability of NAT test for HBV-DNA, HCV-RNA e HIV-RNA, sensitive and reliable, together with epidemiological data, suggest the opportunity to place side by side, in the biological qualification of the blood units, to add the tests for HBV-DNA and HIV-RNA to the test for HCV-RNA mandatory by low, in Italy in the biological qualification of blood units.

Occult hepatitis B virus infection: implications in transfusion

Hepatitis B virus (HBV) presents a higher residual risk of transmission by transfusion than hepatitis C virus (HCV) or human immunodeficiency virus (HIV). While most infectious blood units are removed by screening for hepatitis B surface antigen (HBsAg), there is clear evidence that transmission by HBsAg-negative components occurs, in part, during the serologically negative window period, but more so during the late stages of infection. Donations negative for HBsAg, but positive for HBV DNA, with or without the presence of HBV antibodies, correspond to 'occult' HBV infection (OBI). The frequency of OBI depends on the relative sensitivity of both HBsAg and HBV DNA assays. It also depends on the prevalence of HBV infection in the population. OBI may follow recovery from infection, displaying antibody to hepatitis B surface antigen (anti-HBs) and persistent low-level viraemia, escape mutants undetected by the HBsAg assays, or healthy carriage with antibodies to hepatitis B e antigen (anti-HBe) and to hepatitis B core antigen (anti-HBc). Over time, in the latter situation, anti-HBe and, later, anti-HBc may become undetectable. The critical question is whether or not OBI is infectious by transfusion. All forms have been shown to be infectious in immunocompromised individuals, such as organ- or bone marrow-transplant recipients. In immunocompetent recipients, there is no evidence that anti-HBs-containing components (even at low titre) are infectious. Anti-HBc only, with HBV DNA, can be associated with infectivity, as can rare cases of HBV DNA without any serological HBV marker. If HBV nucleic acid amplification technology (NAT) is considered, the OBI viral load would usually be < 500 IU/ml, making testing of plasma pools unsuitable unless the sensitivity of NAT significantly increases by genome enrichment or test improvement.

Low rate of occult hepatitis B virus infection among anti-HBc positive blood donors living in a low prevalence region in Brazil

OBJECTIVE

The aim of this study was to determine the rate of occult hepatitis B virus (HBV) infection among blood donors living in a geographic region of low (5.6%) anti-HBc prevalence.

SUBJECTS AND METHODS

Sera from 150 candidate blood donors whose blood was rejected due to total anti-HBc reactivity (despite absence of HBsAg) were tested for anti-HBs and IgM anti-HBc antibodies, as well as for HBeAg/anti-HBe. Serum HBV DNA was sought by using a PCR assay able to amplify part of the surface gene. Viral load was measured in the PCR positive samples.

RESULTS

The pattern 'anti-HBc alone' (without HBsAg and anti-HBs antibodies) was found in 64 (42.7%) subjects. IgM anti-HBc and anti-HBe antibodies were detected in 2 (1.3%) and 80 (53.3%) samples, respectively. No sample was HBeAg-reactive. HBV DNA was repeatedly found in five (3.3%) samples, three of which were anti-HBs positive and two anti-HBs negative. All five HBV DNA positive samples showed a low viral load (<1000copies/ml).

CONCLUSIONS

The data indicated a low rate of occult infection among anti-HBc positive, HBsAg negative blood donors living in a region of low prevalence of infection. Viral load was very low in all HBV infected subjects.

Development of a sensitive PCR inhibition method to demonstrate HBV nucleic acid inactivation

BACKGROUND

The evaluation of pathogen reduction technologies with relevant viruses currently contaminating the blood supply is limited by the availability of high-titer virus inocula and sensitive in vitro or in vivo infectivity assays. Because HBV infectivity can only be assessed by in vivo studies with chimpanzees, a sensitive PCR inhibition assay was developed to measure PEN110 inactivation of HBV.

STUDY DESIGN AND METHODS

PCR amplification of 1.1 kb of HBV genome was optimized to determine DNA damage introduced by treatment with PEN110 in RBCs. Inactivation of duck HBV (DHBV) in RBCs, with measurement of the in vitro infectivity, was performed to validate the PCR assay.

RESULTS

The PCR was highly specific and sensitive for amplification of the HBV genome and used to demonstrate a reduction of at least 7.2 and 8.1 log geq per mL within the first 18 hours of PEN110 treatment. PEN110 inactivation of DHBV was also achieved within the first 18 hours with a reduction factor of at least 5.0 log tissue culture infectious dose 50 percent per mL, suggesting that PCR inhibition is an alternative to infectivity assays.

CONCLUSION

This study establishes PCR inhibition as a reasonable approach to assess the efficiency of PEN110 inactivation of human pathogens with human plasma donations that have been found to contain high titers of relevant agents during different stages of infection.

Occult hepatitis B virus infection

The detection of HBV DNA without HBsAg with or without the presence of HBV antibodies outside the acute phase window period defines occult HBV infection. This condition has been described in hepatocellular carcinoma (HCC), chronic hepatitis B, healthy HBV carriage and recovered infection, chronic hepatitis C and individuals without serological markers of HBV. The frequency of the diagnosis depends on the relative sensitivity of both HBsAg and HBV DNA assays. It also depends on the prevalence of HBV infection in the population. Occult HBV in blood donors has a wide range of potential origins within the natural history of the infection. It may originate from recovered infections with anti-HBs and persistent, low-level, viral replication, escape mutants undetected by the HBsAg assays or healthy chronic carriage. The last situation is mostly found with anti-HBc only. Over time, antibody markers may become undetectable leaving HBV DNA as the only marker of the infection. In all cases, the viral load is low, mostly below 10(4) IU/ml, often below 100 IU/ml. At these levels, nucleic acid testing (NAT) in pools is likely to be largely ineffective. Is occult HBV transmissible by transfusion? Carriers of anti-HBs or anti-HBc only were shown infectious in immunosuppressed organ or bone marrow transplant recipients. In immunocompetent recipients, there is no evidence that anti-HBs-containing components are infectious, even in low titre. Donations carrying anti-HBc only and HBV DNA can be infectious and this is a threat where anti-HBc is not screened. Anti-HBc screening identifies most occult HBV infection but not all. HBV NAT needs either extreme sensitivity or to be performed on individual donations to eliminate HBV DNA-containing units.

Prevalence of hepatitis B virus DNA in anti-HBc-positive/HBsAg-negative sera correlates with HCV but not HIV serostatus

BACKGROUND

Hepatitis B virus (HBV) DNA often remains detectable in serum despite clinical recovery and loss of HBsAg.

OBJECTIVE

To study whether coinfection with HIV and HCV influence the chance of detecting HBV DNA in sera with markers of past hepatitis B.

STUDY DESIGN AND RESULTS

The test panel included 160 anti-HBc-positive/HBsAg-negative sera collected in the diagnostic setting. The following parameters were determined in the sera: anti-HIV (32% positive), anti-HCV (34% positive), HCV RNA (18% positive), and anti-HBs (37% positive). A highly sensitive PCR (90%-detection limit 100 copies/ml) amplifying the terminal protein (TP) region of HBV was established and HBV DNA was detected in 12.5% of the samples. In 70% of these samples, the HBV DNA concentration was below 500 copies/ml as measured by real-time PCR in the S gene. Logistic regression analysis revealed that the chance of detecting HBV DNA was increased by a positive HCV serostatus (odds ratio 5.0, 95%-CI 1.6-15.7), whereas HIV coinfection (odds ratio 2.0, 95%-CI 0.7-5.8), anti-HBs (odds ratio 0.9, 95%-CI 0.3-2.6), and HCV RNA status (odds ratio 0.4, 95%-CI 0.1-1.7) had no statistically significant influence. In contrast, the chance of detecting HCV RNA in the subgroup of anti-HCV-positive sera was increased by HIV coinfection (odds ratio 4.5, 95%-CI 1.2-17.4). Sequencing of the TP PCR products revealed neither a specific phylogenetic origin of the circulating HBV DNA nor clustering of uncommon mutations in the TP region.

CONCLUSIONS

The prevalence of HBV DNA in serum of anti-HBc-positive/HBsAg-negative subjects correlates with HCV rather than HIV serostatus.

Evolution of naturally acquired hepatitis B immunity in the long-term hemodialysis population

BACKGROUND

Although the natural history of vaccination-induced hepatitis B virus (HBV) antibodies (Abs) is becoming clearer, little is known about naturally acquired immunity. Some assume that these patients never lose their Abs.

METHODS

To document the natural history of HBV immunity, we prospectively followed up all naturally immune patients initiating hemodialysis (HD) therapy at St Michael's Hospital (Toronto, Canada). Patients presenting with Ab to hepatitis B surface antigen (HBsAb) who had no history of vaccination had a core Ab level measured to confirm natural immunity. When HBsAb titer decreased to less than 10 IU/L, patients were administered a single dose of 40 microg of Engerix B vaccine (Smith Kline Beecham Pharma Inc, Oakville, Ontario, Canada) intramuscularly as a booster dose.

RESULTS

We identified 29 patients beginning HD therapy with natural immunity. Nine patients (30%) subsequently lost immunity (defined as Ab titer decreasing to < 10 IU/L) during follow-up. They were older and had a lower Ab titer at initiation of HD therapy. Four of 5 patients with a low response to the booster dose were 75 years or older. Two patients with a low peak Ab titer after the booster dose again had their Ab titer decrease to less than 10 IU/L after 6 and 10 months. Both patients were switched to intradermal vaccination. All other patients were still immune after a median of 26 months.

CONCLUSION

Individuals who are naturally immune against HBV may experience a decrease in Ab titer. Their responses to booster vaccinations varied widely. It is possible that elderly patients with natural immunity require closer surveillance. We provide recommendations for surveillance in these patients.

Significance of hepatitis B viremia levels determined by a quantitative polymerase chain reaction assay in patients with hepatitis B e antigen-negative chronic hepatitis B virus infection

OBJECTIVES

In hepatitis B e antigen (HBeAg)-negative chronic hepatitis B virus (HBV) infection, the clinical relevance of low viremia levels remains unclear. We evaluated the clinical significance of a single baseline serum HBV DNA measurement by a quantitative polymerase chain reaction (PCR) assay in this setting.

METHODS

In total, 196 patients with HBeAg-negative chronic HBV infection (62 inactive carriers, 134 with chronic hepatitis B) were studied. ALT activity was normal at baseline in 25/134 HBeAg-negative chronic hepatitis B patients (18.7%), whereas it remained normal throughout follow-up in all inactive carriers.

RESULTS

HBV DNA was <30,000 copies/ml in 14 (10.5%) and <100,000 copies/ml in 17 (12.9%) HBeAg-negative chronic hepatitis B patients, whereas it was <30,000 copies/ml in all inactive carriers (undetectable in 14). In particular, HBV DNA levels were <100,000 copies/ml in eight (32%) and <30,000 copies/ml in five (20%) of the 25 patients with HBeAg-negative chronic hepatitis B and normal baseline ALT values. HBV DNA levels with a cut-off at 30,000 or 100,000 copies/ml could correctly classify 92.9% or 91.3% of patients with HBeAg-negative chronic HBV infection, whereas ALT or IgM anti-HBc (IgM class antibody to HBV core antigen) index > 0.200 could correctly classify only 87.2% and 82.1% of patients, respectively. A combined HBV DNA and IgM anti-HBc index performed better by correctly classifying 94.4% of cases.

CONCLUSIONS

Serum HBV DNA levels evaluated by sensitive quantitative PCR assays can be used for differentiation between HBeAg-negative chronic hepatitis B and inactive hepatitis B surface antigen carrier state, but the cut-off level should be set at approximately 30,000 copies/ml and certainly lower than the recently suggested level of 100,000 copies/ml.

A randomized study comparing lamivudine monotherapy after a short course of hepatitis B immune globulin (HBIg) and lamivudine with long-term lamivudine plus HBIg in the prevention of hepatitis B virus recurrence after liver transplantation

BACKGROUND/AIMS

To compare the efficacy in preventing hepatitis B virus (HBV) recurrence of lamivudine vs. lamivudine plus hepatitis B immune globulin (HBIg) after a short course of HBIg and lamivudine in liver transplanted chronic hepatitis B patients.

METHODS

Forty-six patients with HBV cirrhosis received lamivudine before liver transplantation and were then randomized to receive lamivudine plus HBIg for 1 month followed by lamivudine or both drugs for 17 months.

RESULTS

Thirty-two patients were transplanted and 29 were randomized to receive combination therapy (15 cases) or lamivudine monotherapy (14 cases). HBV DNA was undetectable in all cases (17 induced by lamivudine therapy) at the time of liver transplantation. After 18 months of follow-up, all patients survived without HBV recurrence: hepatitis Bs antigen and HBV DNA were negative; however, HBV DNA was detected by polymerase chain reaction in four cases (three with HBIg plus lamivudine and one with lamivudine). Alanine aminotransferase levels were normal except in six cases (one HCV and two HDV coinfections). There were no drug-related adverse events.

CONCLUSIONS

Lamivudine monotherapy after a short course of lamivudine and HBIg is equally as efficacious in preventing HBV recurrence as HBIg plus lamivudine during the first 18 months after liver transplantation. This strategy is more economic and convenient to administer than long-term HBIg plus lamivudine.

Impact of donor infections on outcome of orthotopic liver transplantation

Infection occurs when microbial agents enter the host, either through airborne transmission or by direct contact of a substance carrying the infectious agent with the host. Human body fluids, solid organs, or other tissues often are ideal vectors to support microbial agents and can transmit infections efficiently from donor to recipient. In the case of blood transfusion and tissue transplantation, the main consequence of such a transmission is infection of the recipient. However, in the case of solid-organ transplantation, and particularly for liver transplantation, donor infections are not only transmitted to the recipient, the donor infection also may affect the donated liver's preservability and subsequent function in the recipient irrespective of the systemic consequences of the infection. In addition, solid organ recipients of infected organs are less able to respond to the infectious agent because of their immunosuppressive treatment. Thus, transmission of infections from organ donor to liver recipient represents serious potential risks that must be weighed against a candidate's mortality risk without the transplant. However, the ever-increasing gap between the number of donors and those waiting for liver grafts makes consideration of every potential donor, regardless of the infection status, essential to minimize waiting list mortality. In this review, we will focus on assessing the risk of transmission of bacterial, fungal, viral, and parasitic infectious agents from cadaveric liver donors to recipients and the effect such a transmission has on liver function, morbidity, and mortality. We will also discuss risk-benefit deliberations for using organs from infected donors for certain types of recipients. These issues are critically important to maximize the use of donated organs but also minimize recipient morbidity and graft dysfunction.

Quantitative serum HBV DNA levels during different stages of chronic hepatitis B infection

The goals of this retrospective study were to determine whether there is a threshold hepatitis B virus (HBV) DNA value associated with spontaneous or antiviral therapy-related hepatitis B e antigen (HBeAg) clearance. We also investigated whether there is an HBV DNA value that can be used for differentiating inactive carriers from patients with HBeAg-negative chronic hepatitis B. HBV DNA levels in sequential serum samples of 165 Chinese patients with different stages of chronic HBV infection were quantified by a polymerase chain reaction (PCR)-based assay. Our results showed that almost all of the patients (89%) who remained HBeAg-positive had HBV DNA levels that were persistently above 10(5) copies/mL. Serum HBV DNA levels decreased by a mean of 3 log(10) in patients with HBeAg loss, but 51% had levels above 10(5) copies/mL at the time HBeAg first became undetectable. Mean serum HBV DNA levels were significantly lower in HBeAg-negative patients. HBV DNA value above 10(5) copies/mL would exclude all inactive carriers, but 45% of patients with HBeAg-negative chronic hepatitis would also be excluded if testing were only performed at presentation and 30% would be excluded if testing were performed on 3 occasions. In conclusion, serum HBV DNA levels decreased significantly in patients with HBeAg loss, but there was no threshold HBV DNA level associated with HBeAg clearance. Given the fluctuating course of HBeAg-negative chronic hepatitis, it is not possible to define a single cutoff HBV DNA value for differentiating inactive carriers from patients with HBeAg-negative chronic hepatitis.

Use of hepatitis B core antibody-positive donors for liver transplantation

1. Livers from donors previously exposed to hepatitis B virus (HBV) can fail after transplantation as a result of severe HBV reactivation in the transplant recipient. 2. Antibody against hepatitis B core antigen (HBcAb) in the donor is a marker for risk for transmission of HBV and reactivation after liver transplantation. 3. Recipient HBcAb positivity and antibody to hepatitis B surface antigen (HBsAb) positivity are associated with less risk for HBV reactivation. Conversely, the absence of HBcAb and/or HBsAb in the transplant recipient, higher Child-Pugh score, and presence of HBV DNA in the donor liver may be risk factors for HBV reactivation in the transplant recipient. 4. Recipients of HBcAb-positive (HBcAb(+)) livers at high risk for HBV reactivation should be treated prophylactically with lamivudine alone or a combination of hepatitis B immunoglobulin (HBIg) and lamivudine. The value of monoprophylaxis with HBIg has not been established in this setting. 5. Until data from larger studies are available, for low-risk recipients of HBcAb(+) livers, no prophylaxis, with very close serological and virological monitoring, appears to be a potential alternative to lamivudine monoprophylaxis. 6. Recipients of HBcAb-negative livers should be investigated for HBV infection when an episode of allograft dysfunction is not readily explained by the usual causes (rejection, ischemia, or hepatitis C recurrence).

Approach to the management of allograft recipients following the detection of hepatitis B virus in the prospective organ donor

Hepatitis B virus (HBV) is a highly infectious blood-borne pathogen that can be transmitted by a solid organ allograft and result in substantial morbidity and mortality. Recent advances in the management of HBV infection prompt a reappraisal of the approach to the management of allograft recipients from cadaver donors previously exposed to HBV, because of the on-going shortage of organ donors. This report reviews current knowledge regarding the risk of HBV transmission by an organ from cadaver donors testing positive for markers of HBV infection and makes recommendations for the evaluation, treatment, and surveillance of the allograft recipients.

Virological response to interferon therapy of chronic hepatitis B as measured by a highly sensitive assay

In the interferon (IFN) treatment of chronic hepatitis B, there is no accepted definition of virological response as measured by highly sensitive HBV DNA assays. In the present study of 98 patients given IFN (10 MU/day for 1 week, then 10 MU TIW for 11 weeks) with or without prednisolone priming, a virological response was identified as log HBV DNA/mL below 6.0 (by Amplicor Monitor, Roche) 6 months post-treatment. At this time, 92% (33/36) of the sustained responders (SR) still had detectable viraemia with log HBV DNA/mL at 4.30 +/- 0.15 (+/- SEM), as compared with 8.69 +/- 0.097 in nonsustained responders. Pretreatment viraemia below a threshold at 500 million copies/mL was associated with higher chance of response (P=0.023). Prednisolone enhanced the sustained response (53% vs. 30%, P=0.025), and in particular end-of-treatment response (ETR, 50% vs. 10%, P < 0.0001). ETR was predictive for SR (P < 0.0001), especially when log HBV DNA/mL was < 4.0 (PPV=92%). The potential value of differentiating the therapy of chronic hepatitis B on the basis of viraemia levels, as measured by highly sensitive assays, should be further investigated.

Subcellular localisation of the X protein in HBV infected hepatocytes

Hepatitis B virus X protein (HBx) is a multifunctional protein that exerts its effects primarily by acting as a transcriptional transactivator of viral and multiple host cell genes. HBx is thought to be essential for maintaining viral replication and has been implicated in the development of hepatocellular carcinoma in patients chronically infected with hepatitis B virus. Very little is known about its functional mechanisms and although interactions with several nuclear and cytoplasmic proteins have been demonstrated in vitro, there is no clear consensus as to where HBx localises in infected hepatocytes. In this study, the expression and intracellular distribution of HBx were examined in human liver biopsies using an anti-HBx rabbit polyclonal antiserum. HBx was detected in a high proportion (69%) of samples from patients with chronic HBV infection. Detection of HBx correlated with the absence of cirrhosis and the presence of serum e-antigen. HBx was detected predominantly in the cytoplasm; however, it was also found in the nuclei of up to 20% of positively stained hepatocytes, either exclusively nuclear or localised both in the nucleus and cytoplasm within the same cell. Furthermore, the intracellular distribution of HBx was analysed in transfected Huh-7 cells by confocal microscopy, using the monoclonal antibody 16F1. In these experiments, a substantial nuclear detection was confirmed in a significant proportion of HBx expressing cells. The data indicate a high functional significance of nuclear HBx, consistent with the concept that transactivation may involve interactions with nuclear proteins.