Prevalence of occult HBV infection in haemodialysis patients with chronic HCV

Prevalence of overt and occult hepatitis B virus infections among 135 haemodialysis patients attending a haemodialysis centre at Al-Nasiriyah city, Iraq

Background and Objectives:

The prevalence of Hepatitis B virus (HBV) infection among haemodialysis (HD) patients has been well documented. In addition to overt infection, occult Hepatitis B infection exists in which a patient who is diagnosed seronegative for Hepatitis B surface antigen (HBsAg) shows positive HBV-DNA on using more accurate molecular methods. This study aims to determine the prevalence of overt and occult HBV infection among the HD patients who had attended Al-Nasiriyah dialysis centre during a two-month period.

Materials and Methods:

Serological qualitative detection of HBsAg by rapid test (strips), enzyme immunoassay (EIA, HBsAg) and molecular (real-time polymerase chain reaction (real-time PCR)) was conducted for quantitative detection of HBV in HD patients’ serum.

Results:

The prevalence of overt HBV infection among HD patients was 3.7%. The viral load of HBV positive patients was ranging from 5.85 × 10¹ to 2.16 × 10⁶ copies/ml of serum with median (7.4 × 10⁵ copies/ml). Occult Hepatitis B was not detected in any of the seronegative HD patients (0%). Overt infection was found more in males (80%) than females (20%) (P<0.05). Similarly, infection was found to be higher among patients who had blood transfusions (80%) than those who had not (20%) with statistical significant p<0.05. Although not statistically significant, the mean duration of HD was higher among HBV positive HD patients (17.6) than HBV negative HD patients (14.3). A dual infection of HBV and HCV was not detected in this study.

Conclusion:

Nosocomial transmissions at HD centres and blood transfusion are important risk factors. Besides serological screening, real-time PCR offers a safeguard against the spread of overt and occult HBV infection and determines the viral load of the positive patients.

Occult Hepatitis B Virus Infection in Maintenance Hemodialysis Patients: Prevalence and Mutations in "a" Determinant

Background: Occult hepatitis B virus infection (OBI) is defined as undetectable serum hepatitis B surface antigen (HBsAg) with detectable HBV-DNA in the serum or liver. Patients with maintenance hemodialysis (MHD) are at a high risk of OBI. The prevalence of OBI in MHD patients in China is not well evaluated. In this study, we aim to assess the prevalence of OBI in MHD patients in Sichuan Province, Southwest of China and investigate the mutations in the "a" determinant of HBsAg. Methods: A total of 330 patients undergoing MHD at Sichuan Provincial People's Hospital were enrolled. Serum samples were collected for ELISA assay to test the serological markers of HBV infection, real-time PCR assay to identify the presence of HBV-DNA, and nested PCR plus sequencing analysis to investigate the gene mutations. Results: In a total of 330 MHD patients, we found that the prevalence of OBI was 4.2% (7/165) in the test group, 2.1% (7/330) in the overall dialysis cohort. After a follow-up study of 7 MHD patients with OBI for 2 years, 2 (isolated HBcAb+) of them were still detectable for HBV-DNA. By sequencing analysis, we revealed mutations at the "a" determinant of HBsAg, including Q129R, T131N, M133S, F134L and D144E. The Q129R and M133S mutations were first reported. Conclusions: Our study clarifies the prevalence of OBI in MHD patients in Sichuan Province(4.2% in the test group, 2.1% in the overall dialysis cohort), and demonstrate the mutations of Q129R and M133S in the "a" determinant of HBsAg for the first time.

Occult Hepatitis B Virus Infection Prevalence Among Different Populations of Iran: A Systematic Review and Meta-Analysis

Context: Various frequency rates of occult hepatitis B virus infection (OBI) are reported from different parts of Iran. This systematic review and meta-analysis aimed to characterize the OBI epidemiology in Iran and estimate the pooled prevalence among different populations. Evidence Acquisition: Nine international and Persian electronic databases, as well as some conference proceedings, were searched. Original cross-sectional studies up to December 2018 were included if they investigated the prevalence of OBI by the detection of serum hepatitis B virus surface antigen and hepatitis B virus nucleic acid in at least 30 samples selected with any sampling methods. Comprehensive meta-analysis software was used to analyze the data, and Cochran’s Q-test and I-square statistics were applied to assess the heterogeneity. Meta-regression analysis was performed to assess the impact of the year of study on the OBI frequency. A P value < 0.05 was considered as the level of significance. Results: Of 412 citations found in electronic sources and 35 relevant citations added by searching the gray literature, 83 non-duplicated non-overlapping studies were evaluated. A total of 55 documents comprising 14,485 individuals from 16 provinces met the inclusion criteria and were used in the analysis. The prevalence of OBI considerably varied in different parts of the country with the highest prevalence (63.1%) reported among the HIV-positive population in Fars province. The rates of the OBI prevalence were estimated at 0.06% (95% CI: 0.02 - 0.16%) among blood donors (BDs) regardless of their anti-HBc status, 7.90% (95% CI: 4.33 - 13.99%) among anti-HBc positive BDs, 2.49% (95% CI: 1.2 - 4.81%) among hemodialysis (HD) patients, 4.44% (95% CI: 1.56 - 12.02%) among HIV-positive patients, and 7.76% (95% CI: 4.57 - 12.86%) among HCV-positive patients. No significant trends were observed in OBI prevalence rates among different groups over time (P > 0.05). Conclusions: This review revealed high rates of OBI prevalence among high-risk populations in Iran. It is strongly suggested that occult hepatitis B be investigated among populations with a high chance of its occurrence in our country.

Surveillance and impact of occult hepatitis B virus, SEN virus, and torque teno virus in Egyptian hemodialysis patients with chronic hepatitis C virus infection

OBJECTIVES

Egypt ranks first regarding the prevalence of hepatitis C virus (HCV) infection. Many patients have concomitant diseases like kidney disorders requiring hemodialysis, a procedure carrying the hazard of transmitting other hepatitis viruses. The purpose of this study was to investigate for occult hepatitis B virus (HBV), SEN virus (SENV), and torque teno virus (TTV) among chronic HCV patients on maintenance hemodialysis to identify their impacts.

METHODS

A total of 325 hemodialysis patients were enrolled and divided into two groups based on HCV RNA testing results. Blood samples were collected before hemodialysis. Sera were tested for hepatitis B core antibodies (anti-HBc) and hepatitis B surface antibodies (anti-HBs) using ELISA. HBV, SENV, and TTV DNA were detected by PCR. The serum alanine aminotransferase (ALT) level was measured.

RESULTS

Anti-HBc and HBV DNA were detected in 73.1% and 50.8% of group 1 versus 36.4% and 22.6% of group 2. The serum ALT level was higher in group 1 than group 2. SENV was detected in 11.5% of group 1 versus 8.2% of group 2. TTV was detected in 29% of group 1 versus 27% of group 2.

CONCLUSIONS

There is an increased prevalence of occult HBV in our locality among chronic HCV patients undergoing hemodialysis. The existence of SENV and TTV viremia has no clinical impact.

Molecular and serological characterization of occult hepatitis B virus infection among patients with hemophilia

BACKGROUND

The occult hepatitis B virus infection (OBI) is a health concern among high-risk groups and immunosuppressed individuals. There is still a paucity of data regarding the occult hepatitis B virus infection among hemophilic patients. With this in mind, we aimed to evaluate the molecular prevalence of OBI among clients with hemophilia.

METHODS

Totally, 87 hemophilic patients were selected to be studied. To detect OBI, nested polymerase chain reaction test was used to amplify HBV-S, X, and Core regions. Viral load was determined using an in-house real-time PCR assay. Finally, sequence of S gene was used for genotyping and analysis of mutations.

RESULTS

The mean age of patients was 28.4 ± 5.3 years old, with 90.7% of whom were men. HBV-DNA was detected in eight subjects (9.3%). The rate of OBI was much higher in anti-HBs seronegative subjects than that in other patients (P = 0.019). All OBI cases had HBV genotype D, subgenotype D1. In addition, five out of eight cases (62.5%) showed detectable viral loads (a mean viral load of 4.5 × 10 ² copies/mL). sR73H, sI110L, sP120A, sP127T, sQ129H, sG130R, and sC137S were shown to be the most determinant escape mutation and OBI-relevant mutants.

CONCLUSION

The rate of OBI among the studied population of hemophilia seems to be remarkable. Therefore, screening for OBI must be a routine practice in patients with hemophilia and also patients undergoing immunosuppressive treatments. Amino acid substitutions were observed in the major hydrophilic region. However further investigations are needed for analysis of exact function.

Hepatitis B variants among Egyptian patients undergoing hemodialysis

Hepatitis B virus (HBV) infection is a serious nosocomial infection that affects patients undergoing hemodialysis (HD). However, certain HBV variants are not detected by routine serological tests in Egyptian dialysis units because of mutations that change important viral antigens (Ags). Of note, these mutations can result in the appearance of different HBV variants with different clinical manifestations. Thus, the present study aimed to assess different clinical forms of HBV infections and viral genotypes among patients undergoing HD in the Ismailia governorate of Egypt. To this end, serum samples were collected from 150 patients undergoing HD and screened for HBV-DNA using a nested PCR technique. Positive samples were then screened for HBV serological markers (hepatitis B core antibody [HBcAb], hepatitis B surface antigen, hepatitis B surface antibody, hepatitis B e antigen and hepatitis B e antibody) using ELISA and the HBV viral load quantitated by qPCR. HBV genotypes were detected by direct sequencing of the partial surface (S) gene. The most common clinical form of HBV infection in our study cohort was overt HBV infection (10%); followed by seropositive occult hepatitis B infection (7.3%), most of whom had an isolated HBcAb. The least common form was the precore mutant (1.3%). All HBV isolates were genotype D. This study reveals the importance of HBcAb and PCR in screening for HBV, especially for detection of occult hepatitis B infection.

The prevalence of occult hepatitis B in chronic hepatitis C patients treated with interferon-based antiviral therapy

BACKGROUND AND STUDY AIMS

Occult hepatitis B infection (OBI) is known to be mostly prevalent in chronic hepatitis C (CHC) patients and OBI reactivation might be life-threatening in patients undergoing interferon (IFN)-free direct acting antiviral (DAA) therapy. As previous studies have revealed a relationship between OBI and non-response to IFN-based antiviral therapy, the aim of the current study was to determine if there was a higher prevalence of OBI in IFN non-responders than responders.

PATIENTS AND METHODS

This retrospective cross-sectional study was conducted in CHC patients who had previously received IFN-based antiviral therapy. Serum samples of 100 HBsAg negative CHC patients were tested for HBV DNA, anti-HBc IgG, anti-HBs, ALT and AST. The presence of OBI was compared between 50 IFN responders and 50 IFN non-responders. Patients with a history of previous HBV infection, patients with evidence of cirrhosis and patients who had received IFN therapy within the last one year were excluded from the study.

RESULTS

Anti-HBc IgG positivity was determined in 53% of the patients. HBV DNA positivity, indicating OBI was determined in 1 (1%) patient. This patient was anti-HBc IgG positive, anti-HBs negative, ALT and AST levels were normal. The HBV DNA and anti-HBc IgG positivity rates were higher in the non-responder group than in the responder group, but the difference was not statistically significant (p = 0.31 and p = 0.07 respectively).

CONCLUSION

According to the results of this study, the prevalence of OBI is lower than expected amongst CHC patients in Turkey and it may not be necessary to apply routine screening to IFN non-responders for OBI infection before DAA therapy. However, there is a need for multicentre studies with larger patient series.

Hepatitis B Virus Infection in the Dialysis Population: Current Perspectives

One of the major advances in the management of patients on regular dialysis has been the control of the spread of hepatitis B virus (HBV) infection in dialysis units. The rate of HBsAg positive patients on regular dialysis in the developed world is currently low, but outbreaks of HBV continue to occur. The diffusion of HBV in dialysis units in developing countries is higher, although available information is not abundant. There are limited data on the natural history of HBV in the dialysis population; they support a detrimental effect of HBV on survival in dialysis patients. The HBV viral load in HbsAg-positive dialysis patients appears low and stable over time and numerous mechanisms have been posited to explain it. Several assays for detecting HBV DNA in serum are available but they should not be used for purposes of routine screening within dialysis units. The epidemiology and clinical significance of occult HBV infection in the dialysis population needs to be addressed adequately - this remains an area of active research. Recent recommendations for the management of HBsAg chronic carriers on maintenance dialysis have been issued. No controlled trials for the treatment of hepatitis B with either interferon or lamivudine in dialysis patients are currently available.

Neopterin and soluble CD14 (sCD14) levels as immunoactivation markers in aHBc-only cases

Aim: Isolated hepatitis B core antibodies (aHBc)-only pattern complicates the diagnosis of HBV infections. We evaluated neopterin and sCD14 levels in HBV infections. Methods: aHBc-only (n: 102), healthy control (healthy control group [HCG], n: 100), and chronic hepatitis (CHB) groups (n: 70) were investigated. Competitive and sandwich ELISA were used. Results: The mean neopterin levels were significantly lower in the aHBc-only group than those in the CHB group (p = 0.0001). No significant difference was found between the aHBc-only group and the HCG (p = 0.854). The mean sCD14 levels were lower in the aHBc-only group than those in the CHB group (p = 0.0001), but no significant difference was found between the aHBc-only group and HCG (p = 0.402). No significant difference was detected between aHBc-only and HCG for mean sCD14 (p = 0.402) and neopterin levels (p = 0.854). Conclusion: These two biomarkers are not useful for diagnosing the aHBc only pattern.

Update on occult hepatitis B virus infection

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

Prevalence of occult hepatitis B virus infection in hemodialysis patients in Isfahan, Iran

BACKGROUND

The absence of a detectable hepatitis B surface antigen (HBsAg) with or without hepatitis B core antibody (anti-HBc) or hepatitis B surface antibody (anti-HBs) in the presence of hepatitis B virus-DNA (HBV-DNA) is defined as occult HBV infection. This study was aimed to evaluate the prevalence of occult HBV infection in patients receiving hemodialysis (HD) in Isfahan, Iran.

MATERIALS AND METHODS

This cross sectional study was done on 400 patients without acute or chronic HBV infection with end-stage renal disease undergoing regular HD. Blood samples were collected prior to the HD session, and serological markers of viral hepatitis B included HBsAg, anti-HBs and anti-HBc were measured using standard third generation commercially available enzyme immunoassays kit, then samples of positive anti-HBc and negative anti-HBs were tested for HBV DNA using quantitative real-time polymerase chain reaction techniques. Data were analyzed by SPSS using t-test and Chi-square test.

RESULTS

The mean age of patients was 51.6 ± 11.2 years. Anti-HBc positive was observed in 32 (8%) of 400 studied patients with negative HBsAg. Of 32 patients with anti-HBc positive, 15 were males and 17 were females with mean age of 49.7 ± 12.6 years. Among 32 patients with anti-HBc positive, 10 patients were negative for anti-HBs. All of 10 patients were negative for HBV DNA. The prevalence of occult HBV infection was 0%.

CONCLUSIONS

The prevalence of occult HBV infection in HBsAg negative patients undergoing HD was 0% and look to be among the lowest worldwide. So, occult HBV infection is not a significant health problem in HD patients in this region.

Prevalence and clinical relevance of occult hepatitis B virus infection in patients on the waiting list for kidney transplantation

BACKGROUND

Occult hepatitis B virus (HBV) infection can be defined as the long-lasting persistence of viral genomes in the liver tissue, and sometimes also in the serum at low levels of viremia in individuals with undetectable HBV surface antigen (HBsAg). Viral replication can be reactivated by immunosuppressive therapies or immunologic diseases, leading to the development of typical hepatitis B.

METHODS

All patients on the waiting list for renal transplantation at the only 2 transplant centers in our region (Piemonte, Italy) were checked for the presence of occult HBV infection by an highly sensitive quantitative HBV-DNA polymerase chain reaction (PCR) assay (nested PCR); the only exclusion criterion was HBsAg-positivity. The enrollment lasted from October 1, 2006, to May 31, 2007. The prospective follow-up will continue for 5 years.

RESULTS

HBV-DNA sequences were detected in blood samples from 10 of 300 cases examined (3.3%), being more frequent among Asian (1/3; 33.3%) and African (1/16; 6.25%) subjects as compared with the Caucasians (8/281; 2.8%; P = .011), among anti-hepatitis C virus (HCV) positive versus HCV negative patients (3/32 [9.3%] vs 7/268 [2.6%]; P = .004) and mainly among patients with a previous history of overt liver diseases (3/22 [14%] vs 7/278 [2.5%]; P = .019). HBV-DNA sequences became undetectable at 1 month after renal transplantation in 3 patients; the follow-up is in progress for these and the other patients.

CONCLUSION

Occult HBV infection occurs in patients undergoing renal transplantation. Longer observation and prospective studies will clarify the clinical impact of this occult infection on transplant outcomes and the possibility of viral reactivation related to immunosuppressive therapy.

Occult hepatitis B virus infection among chronic hemodialysis patients in Alexandria, Egypt

The prevalence of end-stage renal disease has increased dramatically in developing countries. Hepatitis B virus (HBV) infection is a global health problem that represents a significant co-morbidity event that has led to outbreaks of hepatitis B. There are inadequate data concerning occult HBV infection among Egyptian chronic hemodialysis patients. This study aimed to detect occult HBV infection among chronic hemodialysis patients in Alexandria, Egypt. A cross-sectional study was performed on 100 patients with end-stage renal disease that received maintenance hemodialysis and had tested negative for HBV surface antigen. Blood samples were collected before the initiation of hemodialysis. Sera were tested for hepatitis C virus (HCV) and hepatitis B core (HBc) antibodies using ELISA, and HBV DNA was detected by SYBR Green real-time PCR using specific primers for the s and c genes and by nested PCR using pol gene-specific primers. The serum activity of alanine and aspartate aminotransferase (ALT and AST) were also measured. Anti-HCV and anti-HBc antibodies were detected in 34% and 48% of patients, respectively, and 70.6% of anti-HCV positive patients were also positive for anti-HBc antibodies. This association was statistically significant (p=0.001). HBV DNA was detected in 32% of the hemodialysis patients. A significant association was determined between the presence of HBV DNA and anti-HCV positivity (p=0.021). Aminotransferases were elevated in 21% of the studied patients, more often in patients with positive anti-HCV profiles than in patients negative for anti-HCV (p<0.05). In conclusion, the serological markers of HBV infection should be verified with molecular tests to investigate possible occult infections, especially among anti-HBc-positive hemodialysis patients, to improve our understanding of their clinical, laboratory, and epidemiological characteristics.

Isolated anti-hbc and occult HBV infection in dialysis patients

Background:

Occult Hepatitis B virus (HBV) infection (OBI) is defined as the presence of HBV-DNA in the liver or serum with undetectable hepatitis B surface antigen (HBsAg). Hemodialysis (HD) patients are at risk of acquiring parenterally transmitted infections.

Objectives:

The aim of this study was to assess the prevalence of OBI in HD patients.

Patients and Methods:

A hundred HBsAg negative HD patients were included in this study from main dialysis units in Tehran, Iran. HBsAg, hepatitis B surface antibody (anti-HBs), hepatitis B core antibody (anti-HBc) and liver enzymes levels were examined in all subjects. The presence of HBV-DNA was determined in plasma samples using real-time PCR.

Results:

A hundredpatients with a mean age of 58.5 ± 16.1 years were enrolled in this study. In total, 56.7% were male and 43.3% female. Anti-HBs, anti-HBc, anti-HCV and anti-HIV were detected in 56.7%, 2%, 5.2% and 1% of patients, respectively. Isolated anti-HBc was detected in 2% of cases. HBV-DNA was detected in 1% of HBsAg negative patients.

Conclusions:

This study showed a low rate of isolated anti-HBc and occult HBV infection in HD patients. It can be due to improvement of people’s knowledge about HBV transmission routes, HBV vaccination of HD patients and regular surveillance of HBV infection.

Prevalence of occult hepatitis B virus infection in kidney transplant recipients

In this cross-sectional study, 207 hepatitis B surface antigen (HBsAg)-negative kidney transplant recipients were evaluated based on demographic and epidemiological data and on the levels of serological markers of hepatitis B virus (HBV) and hepatitis C virus infection and liver enzymes. Patients with HBV or human immunodeficiency virus infection were excluded. Sera were analysed for the presence of HBV-DNA. HBV-DNA was detected in two patients (1%), indicating occult hepatitis B (OHB) infection (the HBV-DNA loads were 3.1 and 3.5 IU/mL in these patients). The results of the liver function tests were normal and no serological markers indicative of HBV infection were detected. The prevalence of OHB infection was low among kidney transplant recipients, most likely due to the low HBsAg endemicity in the general population of the study area.

Prevalence of occult HBV among hemodialysis patients in two districts in the northern part of the West Bank, Palestine

Occult hepatitis B infection is the case with undetectable HBsAg, but positive for HBV DNA in liver tissue and/or serum. Occult hepatitis B infection among hemodialysis patients in Palestine has been understudied. In this study, 148 hemodialysis patients from 2 northern districts in Palestine, Jenin (89) and Tulkarem (59), were investigated for occult hepatitis B, HBV, HCV infections with related risk factors. ELISA and PCR were used for the detection of anti-HBc and viral DNA, respectively. The overall prevalence of occult hepatitis B infection among the study group was 12.5% (16/128). Occult hepatitis B infection is more prevalent among males with most cases (15/16) from Jenin District. About one-third (42/132) of the hemodialysis patients were anti-HBc positive. Approximately 27% of the hemodialysis patients were infected with HCV. Around 20% (28/140) were positive for HBV DNA, but only 8.2% (12/146) of the hemodialysis patients were positive for HBsAg. The comparison between hemodialysis patients with occult hepatitis B infection and those without occult hepatitis B infection for selected risk factors and parameters as liver Enzyme, age, sex, HCV infection, blood transfusion, kidney transplant, anti-HBc, and vaccination showed no statistical significance between both categories. Duration of hemodialysis significantly affected the rate of HCV infection. HCV is significantly higher in hemodialysis patients with both Diabetes mellitus and hypertension. The prevalence of occult hepatitis B infection among hemodialysis patients is high; requiring stringent control policies. HBsAg assay is insufficient test for accurate diagnosis of HBV infection among hemodialysis patients.

Occult HBV infection: a faceless enemy in liver cancer development

The hepatitis B virus (HBV) represents a worldwide public health problem; the virus is present in one third of the global population. However, this rate may in fact be higher due to occult hepatitis B virus infection (OBI). This condition is characterized by the presence of the viral genome in the liver of individuals sero-negative for the virus surface antigen (HBsAg). The causes of the absence of HBsAg in serum are unknown, however, mutations have been identified that produce variants not recognized by current immunoassays. Epigenetic and immunological host mechanisms also appear to be involved in HBsAg suppression. Current evidence suggests that OBI maintains its carcinogenic potential, favoring the progression of fibrosis and cirrhosis of the liver. In common with open HBV infection, OBI can contribute to the establishment of hepatocellular carcinoma. Epidemiological data regarding the global prevalence of OBI vary due to the use of detection methods of different sensitivity and specificity. In Latin America, which is considered an area of low prevalence for HBV, diagnostic screening methods using gene amplification tests for confirmation of OBI are not conducted. This prevents determination of the actual prevalence of OBI, highlighting the need for the implementation of cutting edge technology in epidemiological surveillance systems.

Occult hepatitis B virus infection in hemodialysis patients in Recife, State of Pernambuco, Brazil

INTRODUCTION: Persistence of the hepatitis B virus (HBV) genome in individuals negative for the HBV surface antigen (HBsAg) reflects occult infection. The aim of this study was to identify occult HBV infection among hemodialysis patients at 5 clinics in Recife, State of Pernambuco, Brazil, between August 2006 and August 2007. METHODS: Serum samples underwent enzyme-linked immunosorbent assay to investigate total antibodies against HBcAg (anti-HBc), HBsAg, and antibodies against HBsAg (anti-HBs). Samples that were HBsAg-negative were tested for total anti-HBc, and those that were positive for total anti-HBc were tested for anti-HBs. HBV DNA was investigated with an in-house PCR technique to identify samples positive for total anti-HBc. Subsequently, the samples positive for HBV DNA were sequenced to identify the genotype and mutations. RESULTS: The study population (n = 752) had a mean age of 50 15.1 years and included both sexes. All samples analyzed were negative for HBsAg. The seroprevalence of total anti-HBc was 26.7% (201/752), while that of anti-HBs was 67.2% (135/201). Total anti-HBc alone was detected in 5.7% of the patients. Occult infection was found in 1.5%, comprising genotypes A (33.3%, 1/3) and D (66.7%, 2/3). No mutations were found. CONCLUSIONS: The study detected occult hepatitis B virus infection in hemodialysis patients. Molecular studies on HBV are of fundamental importance because they identify patients that had been considered virus-negative but who, in reality, host the virus and have the ability to transmit it to other patients and staff.

Occult hepatitis B virus infection in hemodialysis patients: a concept for consideration

Hemodialysis patients potentially have an increased risk of infection with parenterally transmitted viral agents due to an impaired host immune response and multiple transfusion requirements. Viral hepatitis is considered as a problem for hemodialysis patients because 1.9% of all deaths among this population are related to the consequence of viral hepatitis. Hepatitis B virus (HBV) is one of the most important causes of transmitted infections by the parenteral route in hemodialysis patients. Occult HBV infection is characterized by presence of HBV infection without detectable hepatitis B surface antigen (HBsAg), which harbors potential risk of HBV transmission through hemodialysis. There are conflicting reports on the prevalence of occult HBV infection (OBI) in hemodialysis patients. Considering the importance of occult HBV infection in hemodialysis patients and the growing evidence on this subject, the purpose of this review is to provide comprehensive information on OBI prevalence in hemodialysis patients and highlight the most important points in this issue.

Epidemiology of occult hepatitis B infection among thalassemic, hemophilia, and hemodialysis patients

CONTEXT

Hepatitis B virus (HBV) is the most common disease commuted through blood transfusion. Occult hepatitis B infection (OBI) is a form of the disease which does not present Hepatitis B surface antigens (HBsAg) in the serum of patients; however, HBV-DNA is detectable in the serum and hepatocytes of patients. OBI is an important risk factor to induce post transfusion hepatitis (PTH), cirrhosis, hepatocellular carcinoma (HCC) and reactivation of the HBV. Recently, several reports from various regions of the world have been published regarding PTH among blood recipients as well as HCC, and cirrhosis among patients who require permanent blood transfusion, including diseases such as hemophilia, hemodialysis and thalassemia. This form of the hepatitis also creates problems for individuals that are co-infected with other viruses such as HCV and HIV. To determine the prevalence of OBI among hemophilia, hemodialysis and thalassemia patients is important because it is a high risk factor for PTH, HCC and cirrhosis therefore, its detection is a critical strategy for most health care services. This review addresses recent information regarding prevalence of OBI in relation to the mentioned diseases.

EVIDENCE ACQUISITION

The data presented here was collected by searching the key words in Pubmed and Scopous databases.

RESULTS

Our searching in the published papers revealed that OBI prevalence is frequent in patients receiving frequent blood transfusions.

CONCLUSIONS

it seems that one of the main mechanisms for OBI transmission is most likely through infected blood and its component and evaluation of the prevalence of OBI in donors and patients, especially those with hemophilia and thalassemia should be foul considered.

Molecular mechanisms underlying occult hepatitis B virus infection

Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section.

Molecular mechanisms underlying occult hepatitis B virus infection

Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section.

Prevalence of occult hepatitis B virus infection in hemodialysis patients from egypt with or without hepatitis C virus infection

BACKGROUND

While prevalence of Hepatitis B virus (HBV) in patients with end-stage renal failure (ESRF) who are undergoing dialysis has decreased significantly during the past few decades, it still remains a distinct clinical problem. The immunosuppressive nature of renal disease often leads to chronicity of the HBV infection and an opportunity for nosocomial spread of the infection among dialysis patients. Egypt is among the countries with intermediate endemicity of HBsAg (range, 2%-7%). Large-scale geographic heterogeneity in HBV prevalence has been reported worldwide and HBV prevalence is especially heterogeneous in Egypt.

OBJECTIVES

To assess the prevalence of occult HBV infection (OBI) in hemodialysis patients with or without chronic hepatitis C (HCV) from Minia and Assuit, Upper Egypt, using HBV DNA assays.

PATIENT AND METHODS

Sera from 145 hemodialysis patients with negative HbsAg were investigated for HBV DNA using real-time polymerase chain reaction (RT-PCR). Only serum samples with repeatedly detectable HBV DNA were considered positive. Patients were divided into 2 groups: HCV RNA positive and HCV RNA negative, based on the results of a third generation enzyme linked immunosorbent assay (ELISA) anti-HCV test and HCV RNA PCR.

RESULTS

HBV DNA was detected in 6 of the 145 patients (4.1%) and HBcAb was detected in 29/145 patients (20%). There were no statistically significant differences in the age, duration of hemodialysis, biochemical parameters, serological markers of HBV, or HBV DNA between patients with and without HCV infection.

CONCLUSIONS

Four percent of the hemodialysis patients had OBI. There was no significant difference in the prevalence of OBI between hemodialysis patients with or without HCV co-infection.

Prevalence of occult hepatitis B virus infection in hemodialysis patients from egypt with or without hepatitis C virus infection

BACKGROUND

While prevalence of Hepatitis B virus (HBV) in patients with end-stage renal failure (ESRF) who are undergoing dialysis has decreased significantly during the past few decades, it still remains a distinct clinical problem. The immunosuppressive nature of renal disease often leads to chronicity of the HBV infection and an opportunity for nosocomial spread of the infection among dialysis patients. Egypt is among the countries with intermediate endemicity of HBsAg (range, 2%-7%). Large-scale geographic heterogeneity in HBV prevalence has been reported worldwide and HBV prevalence is especially heterogeneous in Egypt.

OBJECTIVES

To assess the prevalence of occult HBV infection (OBI) in hemodialysis patients with or without chronic hepatitis C (HCV) from Minia and Assuit, Upper Egypt, using HBV DNA assays.

PATIENT AND METHODS

Sera from 145 hemodialysis patients with negative HbsAg were investigated for HBV DNA using real-time polymerase chain reaction (RT-PCR). Only serum samples with repeatedly detectable HBV DNA were considered positive. Patients were divided into 2 groups: HCV RNA positive and HCV RNA negative, based on the results of a third generation enzyme linked immunosorbent assay (ELISA) anti-HCV test and HCV RNA PCR.

RESULTS

HBV DNA was detected in 6 of the 145 patients (4.1%) and HBcAb was detected in 29/145 patients (20%). There were no statistically significant differences in the age, duration of hemodialysis, biochemical parameters, serological markers of HBV, or HBV DNA between patients with and without HCV infection.

CONCLUSIONS

Four percent of the hemodialysis patients had OBI. There was no significant difference in the prevalence of OBI between hemodialysis patients with or without HCV co-infection.

Post-transfusion occult hepatitis B (OBI): a global challenge for blood recipients and health authorities

Hepatitis B is one of the most frequent post-transfusion infections. Occult hepatitis B infection (OBI) is a form of hepatitis B infection in which, despite the presence of HBV-DNA in the serum and hepatocytes of the carrier, HBsAg is absent. In addition to the risk of transmission through the transfusion of infected blood, reactivation of hepatitis B in OBI patients and recipients of their blood can lead to cirrhosis, hepatic cancer, and reactivation of viral replication in the carrier. Therefore, effective assays to assess and screen for OBI in blood donors are of paramount importance and require urgent attention. Recently, several investigations in various regions of Iran have reported OBI in blood donors. In response, there has been a drive to apply more specific, sensitive, and accurate methods for the detection of HBV, which should become an obligatory screening process for all blood transfusion services. In this review, we address the progression of occult hepatitis B and the common problems associated with occult hepatitis B worldwide. Finally, we reflect on the research and screening that is being performed in Iran to deal with this problem.

Prevalence of occult hepatitis B virus infection

Occult hepatitis B virus (HBV) infection (OBI) is characterized by the persistence of HBV DNA in the liver tissue in individuals negative for the HBV surface antigen. The prevalence of OBI is quite variable depending on the level of endemic disease in different parts of the world, the different assays utilized in the studies, and the different populations studied. Many studies have been carried out on OBI prevalence in different areas of the world and categories of individuals. The studies show that OBI prevalence seems to be higher among subjects at high risk for HBV infection and with liver disease than among individuals at low risk of infection and without liver disease.

Treatment of HBV/HCV coinfection

IMPORTANCE OF THE FIELD

Hepatitis B (HBV) and hepatitis C (HCV) virus infections are among the most common causes of advanced chronic liver disease worldwide. HBV/HCV coinfection is not uncommon with an estimated 7 - 20 million individuals affected worldwide. Patients with HBV/HCV coinfection have an increased risk for cirrhosis, hepatocellular carcinoma (HCC) and even death.

AREAS COVERED IN THIS REVIEW

The pathophysiology of HBV/HCV coinfection is complex, as different patterns of virological dominance may occur, which can even fluctuate over time. Recently, combination of pegylated interferon (PEG-IFN) plus ribavirin has been explored in HBV/HCV coinfected patients who are positive for HCV-RNA. HBV polymerase inhibitors may be indicated if HBV-DNA concentrations are above 2000 IU/ml. In this review, we summarize the epidemiology, viral interaction, its clinical features and the available treatment options.

WHAT THE READER WILL GAIN

Insights into viral interaction of HBV/HCV coinfection and treatment individualization strategies are provided in the review.

TAKE HOME MESSAGE

Detailed serological and virological evaluations are required for HBV/HCV coinfected patients before initiation of antiviral therapy. At present, PEG-IFN-alpha plus ribavirin should be the treatment of choice in patients with dominant HCV replication. However, HBV rebound may occur after elimination of HCV, and thus close monitoring for both viruses is recommended even for patients with initially suppressed HBV-DNA.

Prevalence of occult hepatitis B virus infection in haemodialysis patients from central Greece

AIM: To assess the hepatitis B virus (HBV)-DNA and the prevalence of occult HBV infection in end-stage renal failure (ESRF) patients from Central Greece.

METHODS: Sera from 366 ESRF patients attending five out of six dialysis units from Central Greece were investigated for HBV-DNA by real-time polymerase chain reaction. Only serum samples with repeatedly detectable HBV-DNA were considered positive. IgG antibodies to hepatitis C virus (anti-HCV) were tested by a third generation enzyme linked immunosorbent assay (ELISA), while IgG antibodies to hepatitis E virus (anti-HEV) were tested by two commercially available ELISAs.

RESULTS: HBV-DNA was detected in 15/366 patients (4.1%) and HBsAg in 20/366 (5.5%). The prevalence of occult HBV infection was 0.9% (3/346 HBsAg-negative patients). Occult HBV was not associated with a specific marker of HBV infection or anti-HCV or anti-HEV reactivity. There was no significant difference in HBV-DNA titres, demographic and biochemical features, between patients with occult HBV infection and those with HBsAg-positive chronic HBV infection.

CONCLUSION: In central Greece, 4% of ESRF patients had detectable HBV-DNA, though in this setting, the prevalence of occult HBV seems to be very low (0.9%).

Occult hepatitis B virus infection and lamivudine-resistant mutations in isolates from renal patients undergoing hemodialysis

BACKGROUND AND AIMS

Patients undergoing hemodialysis are at risk of infection with both hepatitis B virus (HBV) and hepatitis C virus (HCV). Occult HBV infection is usually associated with low levels of HBV and is frequently detected in HCV-infected patients. The aims of the present study were to compare the prevalence of occult HBV infection among anti-HCV-positive and anti-HCV-negative patients undergoing hemodialysis, and characterize the molecular patterns of HBV isolates from patients with occult infection.

METHODS

Serum samples from 100 patients negative for hepatitis B surface antigen undergoing hemodialysis, half of whom were positive for anti-HCV antibodies, were tested for the presence of HBV-DNA using semi-nested polymerase chain reaction (PCR). PCR products of the S gene were directly sequenced.

RESULTS

HBV-DNA was detected in 15 samples. There were no significant differences in HCV status, sex, age, time of dialysis, alanine aminotransferase levels or HBV serological markers between patients with or without occult HBV infection, with the exception of antibody to hepatitis B core antigen (anti-HBc)-only serological marker (P = 0.003). All six HBV isolates that could be sequenced were of genotype A/subgenotype A1. Four of these six HBV isolates contained mutations associated with lamivudine resistance in the DNA polymerase (two with L180M/M204V and two with rt173V/180M/204V) and a specific substitution (Y100C) in the HBV small surface protein.

CONCLUSIONS

HBV isolates with the identified substitutions have the potential to spread silently by nosocomial transmission within the hemodialysis unit. These results have potential implications for the management of patients with occult HBV infection undergoing hemodialysis.

KDIGO clinical practice guideline for the care of kidney transplant recipients

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression, graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially on the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.

Occult hepatitis B infection and its possible impact on chronic hepatitis C virus infection

As a well-recognized clinical phenomenon, persistent detectable viral genome in liver or sera in the absence of other serological markers for active hepatitis B virus (HBV) replication is called occult HBV infection. The main mechanism through which occult infection occurs is not completely understood and several possible explanations, such as integration into human genome and maintenance in peripheral mononuclear cells, exist. Occult HBV infection has been reported in different populations, especially among patients with Hepatitis C (HCV) related liver disease. The probable impact of occult HBV in patients with chronic HCV infection has been previously investigated and the evidence suggests a possible correlation with lower response to anti-viral treatment, higher grades of liver histological changes, and also developing hepatocellular carcinoma. However, in the absence of conclusive results, further studies should be conducted to absolutely assess the impact of occult HBV contamination on the HCV related liver disease.

No detected hepatitis B virus-DNA in thalassemic patients infected by hepatitis C virus in Kerman province of Iran

This research was aimed to investigate the prevalence and clinical impact of occult HBV infection in thalassemic patients with chronic HCV infection. In this cross-sectional study we have totally examined 60 patients suffering HBV and HCV infections by PCR and RT-PCR methods, respectively, in Kerman province of Iran. ELISA technique (RADIM, Italy) was used to detect anti-HBc, anti-HBs and HBsAg. The serum level of liver enzymes (SGOT, SGPT, DB, TB and ALK) were analyzed in the HCV infected patients (MAN, IRAN). Statistical analyses performed using t-test and Chi-square. We found that 27 cases (out of 60) were infected by HCV but HBV-DNA was not seen in HCV infected patients. Present findings also showed that none of samples were HBsAg positive but 9 (33%) (out of 27) HCV-RNA positive patients were anti-HBc positive and 11 (40.7%) were positive for anti-HBs. We found that SGOT, SGPT, DB, TB and ALK are above normal in 27 (100%), 19(70.3%), 12(44.5%), 15 (55.5%) and 15 (55.5%) RNA-HCV positive patients, respectively. The prevalence of hepatitis C infection is very high in thalassemic patients and based on other studies our results showed that the prevalence of HCV infection in Kerman is more than other provinces of Iran. In contrast with other studies HBV-DNA in these patients could not be detected, hence, it seems that occult HBV infection isn't frequent in Iranian thalassemic patients who suffering from chronic HCV infection.

Occult hepatitis C virus infection is more common than hepatitis B infection in maintenance hemodialysis patients

Patients of end stage renal disease on maintenance hemodialysis were enrolled to study the prevalence of occult and dual hepatitis B virus (HBV) and hepatitis C virus (HCV) infection and non-occult hepatitis B and C virus infection. One hundred and two patients were enrolled. Thirty patients had HCV infection, three of them were positive in anti-HCV. So, 27 (90%) of HCV-positive patients had occult HCV infection. Eleven (11%) patients had HBV infection. Five patients were positive in anti-HBc or HBV-DNA, but negative in HBsAg (occult HBV infection). Three (3%) patients had dual HBV and HCV infection. None of the patients showed changes in viral markers during the follow-up of 8 mo on average (1-12 mo).

Occult hepatitis B virus infection

The persistence of hepatitis B virus (HBV) genomes in HBV surface antigen (HBsAg) negative individuals is termed occult HBV infection. Occult HBV status is associated in some cases with mutant viruses undetectable by HBsAg assays, but more frequently it is due to a strong suppression of viral replication and gene expression. Occult HBV infection is an entity with world-wide diffusion, although the available data of prevalence in various categories of individuals are often contrasting because of the different sensitivity and specificity of the methods used for its detection in many studies. Occult HBV may impact in several different clinical contexts, including the transmission of the infection by blood transfusion or organ transplantation and its acute reactivation when an immunosuppressive status occurs. Moreover, much evidence suggests that it can favour the progression of liver fibrosis and above all the development of hepatocellular carcinoma.