Antibody level after hepatitis B vaccination in hemodialysis patients: influence of hepatitis C virus infection

Long-term immunogenicity and safety of the hepatitis B vaccine HepB-CpG (HEPLISAV-B) compared with HepB-Eng (Engerix-B) in adults with chronic kidney disease

BACKGROUND

Hepatitis B virus (HBV) infection remains a significant global burden, especially for patients with chronic kidney disease (CKD) receiving hemodialysis. Three doses of HepB-CpG (HEPLISAV-B® vaccine) induced a superior immune response compared with 4 double doses of HepB-Eng (Engerix-B®) in a phase 3 trial (HBV-17) in adults with CKD. Here we report the long-term immunogenicity and safety of HepB-CpG and HepB-Eng in eligible participants of HBV-17 who enrolled in this optional 34-month follow-up trial (HBV-19).

METHODS

HBV-19 is a multicenter, open-label, phase 3b trial of adults with CKD who previously received a complete series of HepB-CpG or HepB-Eng in the HBV-17 trial. Participants were assigned to seroprotection categories at enrollment on the basis of their antibody response to hepatitis B surface antigen (anti-HBs) in HBV-17. The objective was to evaluate the durability of seroprotection (defined as an anti-HBs concentration ≥ 10mIU/mL) induced by HepB-CpG and HepB-Eng. Participants whose anti-HBs concentration was below 10mIU/mL received additional HepB-CpG or HepB-Eng doses.

RESULTS

147 participants were enrolled; 66.7 % were men, median age was 65.0 years, and 83.7 % were white. The durability of seroprotection in participants with CKD was similar in those who received HepB-CpG and those who received HepB-Eng. Antibody concentrations ≥ 100mIU/mL persisted for longer in HepB-CpG than HepB-Eng recipients, among those with anti-HBs ≥ 100mIU/mL post vaccination. The geometric mean anti-HBs concentration in the HepB-CpG group was significantly higher than in the HepB-Eng group over time (P ≤ 0.0001). The safety profiles were similar between the vaccine groups.

CONCLUSIONS

Due to the higher antibody levels induced by HepB-CpG in participants with CKD, seroprotection against HBV may be expected to persist longer than that induced by HepB-Eng.

CLINICALTRIALS

gov: NCT01282762.

An open-label, single-arm study evaluating the immunogenicity and safety of the hepatitis B vaccine HepB-CpG (HEPLISAV-B®) in adults receiving hemodialysis

BACKGROUND

Hemodialysis patients are at increased risk of hepatitis B virus (HBV) infection and are poorly responsive to HBV vaccines. Current vaccine recommendations for hemodialysis patients utilize more than twice the amount of hepatitis B surface antigen (HBsAg) used for healthy adults and achieve lower immune responses.

METHODS

An open-label, single-arm, multicenter trial was conducted among adults 18 years of age and older who were initiating or undergoing hemodialysis who had not previously received hepatitis B vaccine. Participants received four doses of HepB-CpG (HEPLISAV-B®) (20 mcg rHBsAg + 3000 mcg CpG 1018, a Toll-like receptor 9 agonist) administered at 0, 4, 8, and 16 weeks. Participants are being followed for 68 weeks. This paper reports the final immunogenicity analysis of the primary endpoint at study week 20 and an interim safety analysis.

RESULTS

We enrolled 119 participants receiving hemodialysis who were followed for a median of 47.4 weeks. Of the 119 participants, 75 were in the per-protocol population. At week 20, the seroprotection rate (% with antibodies to hepatitis B surface antigen [anti-HBs] ≥ 10 mIU/mL) was 89.3% and the percentage of participants with anti-HBs ≥ 100 mIU/mL was 81.3%. The anti-HBs geometric mean concentration was 1061.8 mIU/mL. HepB-CpG was well tolerated with no observed safety concerns.

CONCLUSION

In patients receiving hemodialysis, HepB-CpG given as four doses was well tolerated and induced very high anti-HBs concentrations and seroprotection in a very high proportion of recipients.

Effectiveness of a hepatitis B vaccination program at two tertiary hemodialysis centers

INTRODUCTION

Hemodialysis (HD) patients are at increased risk of hepatitis B infection in comparison to the general population. Despite a more intensified hepatitis vaccination regimen, response rates in HD patients are typically low. The study was conducted to quantify response rate to a new hepatitis B vaccination protocol initiated in late 2015, determine risk factors affecting response rate, and assess adherence to protocol.

METHODS

This retrospective chart review evaluated all HD patients eligible for hepatitis B vaccination in two large dialysis clinics from initiation of the hepatitis B protocol to July 2017. Recombinant hepatitis vaccine (Recombivax® HB) 40 μg was administered in a 3-dose regimen at months 0, 1, and 6 to patients with hepatitis B surface antibodies (anti-HBs) <10 mIU/mL. A repeat series was given if anti-HBs levels remained below 10 mIU/mL after the first series. A booster dose was given if anti-HBs titers fell below 10 mIU/mL after initial response to a second series vaccination.

FINDINGS

Of 411 patients at the two HD centers, 142 patients received hepatitis B vaccination with a total of 168 vaccine courses given, series 1: n = 86, series 2: n = 60 and booster: n = 22. Response rates to vaccination were 61.4%, 58.3%, and 81.8%, respectively. In univariate analysis, adherence to protocol significantly affected response rate (P = 0.035). A multivariate analysis assessing response rates to series 1, 2 or booster confirmed that adherence was a significant risk factor (OR = 2.2; 95% CI 1.4-3.4; P = 0.0005).

DISCUSSION

This was the first study to examine adherence to regimen and identified adherence as an important predictor of vaccine response. Adherence is one of the few modifiable risk factors that can be optimized in an effort to improve response to hepatitis B vaccination.

Factors affecting inadequate response to HBV vaccine in hemodialysis patients: northeast anatolia survey with six hemodialysis centers

BACKGROUND

In hemodialysis patients Hepatitis B virus (HBV) infection is one of the problems. Because of HBV vaccine response is lower than in the general population, in this study it is aimed to determine the factors that may cause inadequate HBV vaccine response in hemodialysis patients.

METHODS

In study, HBsAg, anti-HBs, anti-HBc IgG data belonging to 278 patients were obtained from file and computer records. It was seen that seronegative cases had been given recombinant HBV vaccine. Anti-HBs titers were monitored 1 month after vaccination was completed. According to this, the patients are divided into two groups. Those with anti-HBs < 10 IU/mL were identified as non-responders and with anti-HBs ≥ 10 IU/mL as responders. Factors such as age, serum albumin and urea reduction rate which may affect inadequate response to HBV vaccine were evaluated. As statistical examination, Chi-square test was used for the analysis of the data determined by counting, and logistic regression was used for statistically significant independent variables in chi-square test. p value of < 0.05 was considered statistically significant (Confidence interval: 95%).

RESULTS

Out of 278 patients, according to exclusion criteria 81 patients were excluded. 13.2%(26/197) of HBV vaccinated patients had insufficient response. The inadequate response rate to HBV vaccination was found to be higher in patients with age ≥ 65 (p = 0.039), serum albumin < 3.5 g/dL (p = 0.024) and urea reduction rate ≤ 65 (p = 0.028). No statistically significant relationship was found between inadequate response to HBV vaccine and anti-HCV positivity, presence of diabetes mellitus, anemia status, vitamin D therapy and vascular access pathway variability.

CONCLUSION

We conclude that relatively high patient age, low albumin level and insufficient urea reduction rate may cause inadequate HBV vaccine response. Taking these factors into consideration may provide a useful insight for an adequate response to vaccination.

Immune response to hepatitis B vaccination in HIV-positive individuals with isolated antibodies against hepatitis B core antigen: Results of a prospective Italian study

BACKGROUND AND AIM

Antibodies against hepatitis B core antigen (anti-HBc) are found in 14-44% of patients with HIV infection, but it is still unclear whether hepatitis B virus (HBV) vaccination should be recommended for HIV-positive subjects with isolated anti-HBc (IAHBc). We examined the rate of anamnestic and primary responses (ARs and PRs) and associated factors in a group of HIV-infected patients with an IAHBc profile.

METHODS

This prospective study recruited 25 HIV-positive patients with anti-HBc alone who were vaccinated against HBV infection. Those without an AR (anti-hepatitis B envelope antigen [anti-HBs] levels of <10 U/L) or who were hypo-responsiveness (anti-HBs levels of >10 but <100 U/L) four weeks after the first dose of vaccine underwent a full course of vaccinations. Their clinical and virological data, including the presence of occult hepatitis B infection (OBI), were evaluated in accordance with the vaccination schedule.

RESULTS

Six of the 25 patients (24%) showed an AR, four of whom had anti-HBs levels of <100 U/L. Ten of 19 (52.6%) remaining patients became seroprotected after the third dose. OBI was detected in four of the six patients with an AR, two of the 10 patients with a PR, and none of the nine patients who did not respond. Multivariate analysis showed that an AR was associated with the presence of OBI (P = 0.0162), and a PR was associated with HCV antibody status. (P = 0.0191).

CONCLUSIONS

Our data suggest that testing for anti-HBc alone may not be a reliable means of assessing protection from HBV infection in HIV-positive patients. OBI-positive patients may benefit from a single vaccine dose. Anti-HCV serostatus may affect PRs.

Evaluation of Response to Hepatitis B Vaccination in Chronic Hemodialysis Patients

Background:

Hemodialysis (HD) patients are at an increased risk of acquiring hepatitis B virus (HBV) infection. Active HBV immunization in these patients is recommended. A response rate in HD patients is variable but generally lower than healthy individuals.

Objective:

The aim of this study is to assess the response of HD patients to the HBV vaccine and correlate response and long-term immunity to various clinical and biomedical factors.

Patients and Methods:

One hundred and one patients, with a mean age 48.7 ± 18.5 years, received 40 μg of HBV vaccine administered intramuscularly in the deltoid region at 0, 1, 2 and 6 months. The patients' responses to the vaccine were determined by measuring hepatitis B surface antibody (HBsAb) 6 weeks after the last injection and monitored thereafter at 3-month intervals.

Results:

Seventy-one patients (70.3%) mounted a response with HBsAb >10 mIU/ml 6 weeks following the fourth dose of vaccine, and thus were considered considered as adequate responders. Forty-nine (48.5%) patients mounted an excellent response with HBsAb >100 mIU/ml 6 weeks after the fourth dose. Thirty patients (29.7%) were nonresponders. Responders were significantly younger than nonresponders (P = 0.01). Gender, hemoglobin level, serum albumin, ferritin, parathyroid hormone level and hepatitis C virus infection had no effect on the response to the vaccine. Similarly, there was no difference in diabetic state and adequacy of HD between the two groups. Fifty-nine patients (88%) had persistent protective antibodies at 1 year, while eight (12%) lost such protection. Predictors of persistent immunity at 1 year were high HBsAb level at the completion of the vaccination regime and, to a lesser extent, young age.

Conclusion:

A 70% response rate to HBV vaccine was observed in the cohort of this study. Young age predicts a favorable response to HBV vaccine in HD patients. High (>100 mIU/ml) HBsAb levels achieved at vaccine completion predict persistent immunity at 1 year.

Factors affecting responsiveness to hepatitis B immunization in dialysis patients

BACKGROUND

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are widespread health problems all over the world and have high morbidity and mortality. Hemodialysis patients are more frequently exposed to these viruses as they have poor immune system and frequently undergo parenteral interventions. The vaccination against HBV prevents infection and it has been recommended for the prevention of HBV infection in all susceptible dialysis patients. This study aimed to determine the seroprevalence of HBV and HCV infections and analyzed the factors affecting inadequate response to HBV vaccine in dialysis patients.

METHODS

The data for 584 dialysis patients that were followed up at seven dialysis centers were analyzed. The patients received four doses of 40 μg recombinant hepatitis B vaccine at 0, 1, 2, and 6 months and were tested for anti-HBs titer after one month of completion of vaccination. If patients showed a titer of anti-HBs <10 IU/mL, an additional 40 μg in four vaccine doses was administered immediately and they were retested for the anti-HBs following the same schedule. The patients were divided into two groups: responders and non-responders.

RESULTS

HBsAg and anti-HCV seroprevalence was 3.4% and 10.3%, respectively. After vaccination schedule, 264 (83.5%) patients had antibody response to HBV vaccine and 52 (16.5%) had no response. Hepatitis B vaccine unresponsiveness is more common in the patients with hepatitis C positivity (p = 0.011), BMI >30 (p = 0.019), over the age of 65 years (p = 0.009), and duration of dialysis treatment >5 years (p = 0.001). There was no statistically significant difference between gender, causes of renal disease, erythropoietin treatment, and the type of dialysis.

CONCLUSION

Hepatitis C infection, obesity, being elderly, and having long hemodialysis period reduced the hepatitis B vaccination response in hemodialysis patients.

Novel Perspectives on the Hepatitis B Virus Vaccine in the Chronic Kidney Disease Population

Background

The prevalence and incidence rates of hepatitis B virus (HBV) among patients undergoing maintenance dialysis in developed countries have declined over the last 2 decades thanks to the implementation of numerous infection control procedures in dialysis units, including the hepatitis B vaccine. It is well known that the immune response against HBV vaccine is unsatisfactory in the chronic kidney disease (CKD) population. The seroprotection rate after the HB vaccine schedule is low and the anti-HB titers are reduced, falling logarithmically over time.

Purpose

We did an extensive review of the medical literature on the mechanisms underlying the reduced response rate towards the HBV vaccine in patients with CKD. The efficacy and safety of HBV vaccines for use in the CKD population was also evaluated.

Results

Currently available vaccines against HBV are mostly plasma-derived or manufactured by recombinant DNA technology (yielding the S protein of the HBV envelope). The most promising strategy to enhance the immune response toward the HBV vaccine in the dialysis population is given by adjuvanted vaccines. Second-generation recombinant HB vaccines provided with a novel adjuvant (AS04, made of 3- O-4′-desacyl-monophosphoryl lipid A adsorbed on aluminum phosphate) demonstrated improved immunogenicity but a number of patients with an unsatisfactory response still occurs. Additional second-generation vaccines containing nonaluminum-based adjuvant systems such as AS02 (3- O-desacyl-4′-monophoshoryl lipid A and QS21) or 1018 (a Toll-like receptor 9 agonist) have shown higher immunogenicity and acceptable safety in the CKD population. The evidence in patients with end-stage renal disease is extremely limited on the use of third-generation vaccines, recombinant HBV vaccines expressed in mammalian cells containing S/Pre-S antigens.

Conclusions

The immunogenicity of HBV vaccines in patients with CKD is suboptimal but novel technologies promise to give better results in the near future.

Hepatitis B vaccine by intradermal route in non responder patients: An update

Vaccination is the main prophylactic measure to reduce the mortality caused by hepatitis B virus (HBV) infection in healthy subjects since the immune response to hepatitis B recombinant vaccination occurs in over 90% of general population. Individuals who develop an anti-HBs titer less than 10 mIU/mL after primary vaccination cycle are defined “no responders”. Many factors could cause a non response to the HBV vaccination, such as administration of the vaccine in buttocks, impaired vaccine storage conditions, drug abuse, smoking, infections and obesity. Moreover there are some diseases, like chronic kidney disease, human immunodeficiency virus infection, chronic liver disease, celiac disease, thalassaemia, type I diabetes mellitus, down’s syndrome and other forms of mental retardation that are characterized by a poorer response to HBV vaccination than healthy subjects. To date it is still unclear how to treat this group of patients at high risk of hepatitis B infection. Recent studies seem to indicate that the administration of HBV recombinant vaccine by the intradermal route is very effective and could represent a more useful strategy than intramuscular route. This review focuses on the use of anti hepatitis B vaccine by intradermal route as alternative to conventional intramuscular vaccine in all non responder patients. A comprehensive review of the literature using PubMed database, with appropriate terms, was undertaken for articles in English published since 1983. The literature search was undertaken in September 2013.

Hemodialysis and hepatitis B vaccination: a challenge to physicians

Hepatitis B is responsible for the development of half of hepatocellular carcinoma cases and is a major cause of hepatic insufficiency. The vaccine against hepatitis B virus does not exhibit the same high efficacy in patients on hemodialysis as it does in immunocompetent individuals. The medical literature recommends vaccination with four doses (40 mg each) of the hepatitis B virus vaccine before beginning hemodialysis; however, approximately one-third of hemodialysis patients do not respond to this vaccination schedule. A new serologic test should be performed each year for individuals who respond adequately, whereas a booster dose should be offered to those with antibody titers below 10 mIU/mL. In this study, we followed 83 hemodialysis patients and collected quantitative serologic measurements every 2 months over a 1-year period. We made the measurements 1 month after the vaccination period. We found that 41% of the patients had antibody titers below 10 mIU/mL (nonresponders), 21.7% had antibody titers between 10 mIU/mL and 100 mIU/mL (poor responders), and 37.3% had antibody titers higher than 100 mIU/mL (good responders). Patients with diabetes and/or hypertension exhibited worse response to vaccination. All subjects displayed decreasing antibody titers during the observation period. The group of poorly responsive patients had antibody titers below 10 mIU/mL at the 6-month follow-up period.

Association of the interleukin-12 polymorphic variants with the development of antibodies to surface antigen of hepatitis B virus in hemodialysis patients in response to vaccination or infection

Cytokines, involved in the T-helper 1 system, play a role in the regulation of hepatitis B virus (HBV) clearance and the immune response to HBV antigens during natural infection or planned vaccination. Our aim was to examine whether the polymorphic variants of IL-12 are equally associated with development of antibodies to HBV surface antigen (anti-HBs) in hemodialysis (HD) patients in the case of HBV vaccination or HBV infection. The IL-12A rs568408 and IL-12B rs3212227 polymorphisms were analyzed in relation to anti-HBs development in 602 HD patients with negative antibodies to HBV core antigen (anti-HBc) who were hepatitis B vaccinated (group I) as well as in 237 anti-HBc positive HD patients who were infected with HBV in the past (group II). In group I, 199 patients did not develop an anti-HBs titre >10 IU/L (subgroup Ia), whereas in group II, 55 patients did not develop an anti-HBs titre >10 IU/L (subgroup IIa). Patients of groups I and II that developed an anti-HBs >10 IU/L were included into subgroups Ib and IIb, respectively. In hepatitis B vaccinated HD patients, development of a protective anti-HBs titre was positively associated with vintage of renal replacement therapy (RRT), chronic glomerulonephritis as a cause of RRT, and GA rs 568408 IL-12A (OR 1.6, 95 % CI 1.0-2.5, P = 0.035), but a frequency distribution of this genotype between responders and non-responders was not significant when the Bonferroni correction was applied. In HBV infected HD patients, anti-HBs development was positively associated with AC rs3212227 IL-12B (OR 8.0, 95 % CI 2.6-24.9, P < 0.001), whereas HBsAg positivity, AA rs3212227 IL-12B (OR 0.3, 95 % CI 0.1-0.7, P = 0.007), and CC rs3212227 IL-12B (OR 0.1, 95 % CI 0.03-0.6, P = 0.011) were negative predictors of positive anti-HBs phenotype. When the Bonferroni correction was applied, if appropriate, these associations remained significant. In HD patients, the studied IL-12 polymorphic variants seem to be associated with the anti-HBs phenotype (a) with borderline significance for IL-12A in hepatitis B vaccinated patients, and (b) significantly for IL-12B in patients who underwent natural HBV infection.

Immunogenicity and safety of an investigational hepatitis B vaccine with a toll-like receptor 9 agonist adjuvant (HBsAg-1018) compared with a licensed hepatitis B vaccine in patients with chronic kidney disease

BACKGROUND

Hemodialysis patients are at increased risk of hepatitis B virus (HBV) infection and patients with chronic kidney disease (CKD) are commonly hyporesponsive to HBV vaccines. Current recommendations for CKD patients are to utilize 4 double-doses (2×20 mcg HBsAg) of a licensed hepatitis B vaccine (HBsAg-Eng).

METHODS

An observer-blind, randomized, active-controlled, parallel group, multicenter trial was conducted among 521 patients 18-75 years of age with CKD, comparing 3 single doses of an investigational hepatitis B vaccine (20 mcg rHBsAg+3000 mcg 1018, a toll-like receptor 9 agonist) given at 0, 4, and 24 weeks to 4 double-doses of HBsAg-Eng (2×20 mcg rHBsAg+500 mcg alum) given at 0, 4, 8, and 24 weeks (total of 8 injections). Participants were followed for 1 year.

RESULTS

Among 467 participants in the modified intent-to-treat population, at the primary endpoint at week 28, the seroprotection rate (SPR: % with anti-HBs≥10mIU/mL) in the HBsAg-1018 group (89.9%) met criteria for noninferiority and superiority to the SPR in the HBsAg-Eng group (81.8%). At week 28, the percentage of participants with anti-HBs≥100mIU/mL in the HBsAg-1018 group (73.6%) was significantly higher than in the HBsAg-Eng group (63.2%). In addition, the geometric mean concentration of anti-HBs in the HBsAg-1018 group (587.1mIU/mL) was significantly higher than in the HBsAg-Eng group (156.5mIU/mL). At weeks 8 and 12 after the first study injection, SPRs in the HBsAg-1018 group were significantly higher than in the HBsAg-Eng group. At 52 weeks, the immune response to HBsAg-1018 remained higher than to HBsAg-Eng. HBsAg-1018 was generally well tolerated and had a similar safety profile to HBsAg-Eng.

CONCLUSION

In CKD patients, 3 doses of HBsAg-1018 induced significantly higher seroprotection, earlier seroprotection, and more durable seroprotection than 4 double doses of HBsAg-Eng.

Vaccination strategies in patients with IBD

Patients with IBD are at increased risk of infection, in part owing to the disease itself, but mostly because of treatment with immunosuppressive drugs. Although many of these infections are vaccine-preventable, vaccination coverage in patients with IBD is extremely low. The vaccine strategies examined in this Review are based on data that enable us to provide practical advice for clinicians. Clinical evidence indicates that vaccines do not increase the risk of relapse in patients with IBD. Live vaccines are contraindicated in immunocompromised individuals, but inactivated vaccines can be safely administered. Most patients receiving immunosuppressive therapy develop an immune response after vaccination, but response rates might differ from those of nonimmunosuppressed individuals. Therefore, vaccination status should be checked and updated upon diagnosis of IBD.

Kinetics of anti-hepatitis B surface antigen titers after hepatitis B vaccination in patients with inflammatory bowel disease

BACKGROUND

Clinically significant hepatitis B (HB) virus infection has been documented among immunocompromised patients who do not maintain anti-hepatitis surface antigen (anti-HBs) concentrations ≥ 10 IU/L after an adequate response to the vaccine. The aims of the study were to understand the kinetics of anti-HBs titers over time in patients with inflammatory bowel disease (IBD) who initially responded to vaccination and to identify factors predictive of losing protective anti-HBs titers.

METHODS

Patients with IBD with a response (anti-HBs > 10 IU/L at 1-3 months) to HB virus vaccination were prospectively included. Anti-HBs titers were measured at 6 and 12 months. Anti-HBs titers were considered negative if they were <10 IU/L at any time during the follow-up. The kinetics of anti-HBs titers in the long term was estimated using Kaplan-Meier curves. Cox regression analysis was performed to identify the factors predictive of losing protective anti-HBs titers.

RESULTS

The sample comprised 100 patients (mean age, 42 years; 68% Crohn's disease; 49% on thiopurines; and 14% on anti-tumor necrosis factors during follow-up). The cumulative incidence of loss of anti-HBs titers was 2% after 6 months and 15% after 12 months. The incidence rate of loss of protective anti-HBs titers was 18% per patient-year. Baseline (after vaccination) anti-HBs titers were lower among patients whose titers became negative during the follow-up than among those who maintained them >10 IU/L (191 versus 515 IU/L; P < 0.001). Treatment with anti-TNFs was the only factor associated with a higher risk of loss of anti-HBs (hazard ratio = 3.1; 95% confidence interval = 1.1-8.8; P = 0.03).

CONCLUSIONS

A high proportion of patients with IBD with protective anti-HBs titers after vaccination lose them over time (18% per patient-year of follow-up). The risk of losing protective anti-HBs titers is 3-fold higher among patients on anti- tumor necrosis factors therapy.

Hepatitis B vaccination in chronic kidney disease: review of evidence in non-dialyzed patients

CONTEXT

Hepatitis B vaccination of hemodialysis patients is performed all over the world. There are also recommendations from world health organizations to vaccinate patients with chronic kidney disease (CKD) prior dialysis commencement, but the implementation of a hepatitis B vaccination program is less common and not well organized.

EVIDENCE ACQUISITION

This review article summarizes data indicating why, when and how to vaccinate CKD patients before they start renal replacement therapy. Publication for this review was bringing into being from PubMed.

RESULTS

There is an agreement in the nephrological societies and among clinicians and scientists that CKD patients should be vaccinated in early stages of their disease, because a higher glomerular filtration rate is more likely to be associated with the responsiveness to vaccination. Schedules of vaccination and optimal vaccine doses are still being investigated. Differences in data with respect to these problems may result from comparisons of various vaccine doses and vaccination schedules without reference to one gold standard, variations in patients` clinical status and glomerular filtration rate, and also the small groups of the affected patients make statistical analysis non-conclusive. A titer of antibodies to surface antigen of hepatitis B virus (anti-HBs) > 10 IU/L or ≥ 10 IU/L is commonly considered as a marker of seroconversion to anti-HBs positivity after vaccination in both non-dialyzed and dialyzed patients. In advanced CKD, vaccine-induced serconversion rate is seldom observed in more than 90% of vaccinees. Various strategies have been utilized in order to increase vaccine-induced seroconversion rate in patients with advanced CKD. Changing the injection mode, the use of adjuvants and immunostimulants to improve the immunogenicity of existing recombinant hepatitis B vaccines, introduction of mammalian-cell derived pre-S/S HBV vaccines (third-generation vaccines) were tried in order to improve the immunization rate.

CONCLUSIONS

There are a substantial number of non-responders to the hepatitis B vaccine among CKD patients. Therefore, successful prevention of hepatitis B virus transmission and spread will only be attained when hepatitis B vaccination is applied together with full implementation of appropriate infection control procedures.

Future prevention and treatment of chronic hepatitis B infection

Vaccination for hepatitis B virus (HBV) infection and treatment for chronic hepatitis B, while effective for primary prevention and control of the disease, still have their limitations. Global coverage of HBV immunization needs improvement. Several patient populations are noted to have suboptimal seroprotective rates after HBV vaccination. There are currently several potential new vaccines undergoing animal and human studies, most notably vaccines containing immunostimulatory DNA sequences. Long-term nucleoside analogue therapy is necessary in achieving permanent virologic suppression. Potential new treatments explore new mechanisms of action, including the inhibition of hepatitis B surface antigen release, targeting antifibrotic mechanism, and immunomodulation through novel interferons and therapeutic vaccines. The clinical application of potential new vaccines and therapies would enhance the prevention of HBV infection and treatment of chronic hepatitis B.

Improving hepatitis B vaccine efficacy in end-stage renal diseases patients and role of adjuvants

Hepatitis B virus (HBV) infection is a serious global health problem.The prevalence of viral hepatitis is higher in dialysis patients than in the general population because of the opportunity for exposure during the dialysis procedure. Immunization is the most effective way to prevent transmission of hepatitis B virus (HBV) and hence the development of acute or chronic hepatitis B. It is well established that patients with end-stage renal disease including dialysis-dependent patients, have an impaired immune response to hepatitis B vaccine. End stage renal diseases (ESRD) patients have lower seroconversion rates compared with the subjects with intact renal function. Moreover, even after the completion of vaccination schedule anti-hepatitis B (anti-HBs) titers of responder dialysis, patients are low and decline logarithmically with time. The impaired efficacy of HBV vaccine in patients with ESRD has been attributed to numerous factors such as immune compromise because of uremia and some other factors. One approach to improve the immunogenicity of existing HBV vaccines is adjuvantation, and it's very important to find more effective adjutants for improving HBV vaccine efficacy. In this paper we have a brief review on recently known new ways for improving HBV vaccine efficacy.

Erythropoietin use and immunogenicity of hepatitis B virus vaccine in chronic kidney disease patients: a meta-analysis

BACKGROUND

It is known that the immunogenicity of hepatitis B virus (HBV) vaccine is lower in uremic patients than healthy subjects. Numerous inherited or acquired factors have been implicated in this lowered response, and the high frequency of recombinant human erythropoietin use among patients on maintenance dialysis has been suggested to play a pivotal role. However, the impact of therapy with recombinant erythropoietin on the immune response to HBV vaccine in patients with chronic kidney disease (CKD) is not appropriately detailed.

AIM

To evaluate the influence of human recombinant erythropoietin therapy on the immunological response to HBV vaccine in CKD patients by performing a systematic review of the literature with a meta-analysis of clinical studies.

METHODS

We used the random-effects model of DerSimonian and Laird with heterogeneity and sensitivity analyses. The end-point of interest was the rate of patients showing seroprotective anti-hepatitis B titers at completion of a hepatitis B vaccine schedule among human erythropoietin users versus those who did not receive the drug in a CKD population.

RESULTS

We identified 11 studies involving 862 unique patients with CKD. Aggregation of study results did not show a significant increase in response rates among erythropoietin user versus non-user patients (pooled odds ratio = 1.431; 95% CI 0.954; 2.146), according to a random-effects model. No heterogeneity was found, the p value was 0.1 for our test of study heterogeneity (Q = 14.147). Stratified analysis in various subgroups of interest did not significantly change these findings.

CONCLUSIONS

Our meta-analysis showed no link between immunological response to HBV vaccine and therapy with human recombinant erythropoietin among individuals on long-term dialysis. We suggest the use of recombinant vaccine towards hepatitis B in patients on regular dialysis irrespective of erythropoietin treatment.

Meta-analysis: the impact of nutritional status on the immune response to hepatitis B virus vaccine in chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) typically show a diminished immune response to hepatitis B virus (HBV) vaccine compared with individuals with intact kidney function. A number of inherited or acquired factors have been implicated in this suboptimal response. Patients with chronic kidney disease frequently have a compromised nutritional status; however, the impact of malnutrition on the immune response to hepatitis B virus vaccine in chronic kidney disease patients remains unclear.

AIM

To evaluate the influence of nutrition status on the immune response to HBV vaccine in CKD population by performing a systematic review of the literature with a meta-analysis of clinical studies.

METHODS

Study-specific relative risks were weighted by the inverse of their variance to obtain fixed- and random-effects pooled estimates of impaired vaccine response across the published studies. The risk of poor serological response to HBV vaccine in chronic kidney disease population according to nutritional parameters was regarded as the most reliable outcome end-point. Only studies performing multivariate analysis in order to make adjustments for potential confounders were included.

RESULTS

We identified seven studies (15,172 unique patients with CKD). The serum protection rate after a full course of recombinant or plasma-derived vaccine towards HBV ranged between 40 and 86%. Aggregation of study results showed an independent and adverse effect of poor nutrition status, as mostly detected by serum albumin levels, on the protection rate after HBV vaccine course; the summary estimate for adjusted RR was 1.50 with a 95% confidence interval (CI) of 1.02, 2.21; R( i ) = 0.01 (random-effects model). The P value for study heterogeneity was significant (Q = 0.0001). In the subgroup of patients who received HBV recombinant vaccine, the relative risk of impaired serological response after HBV vaccination was 1.63 (95% CI, 1.08, 2.45), R( i ) = 0.90, Q = 0.00001, with poor nutritional parameters at baseline.

CONCLUSIONS

An increased risk exists of impaired serologic response to HBV vaccine response among chronic kidney disease patients having poor nutrition status. Additional studies are needed to understand better the mechanisms underlying the relationship between nutritional status and serological response to HBV vaccine among patients with CKD.

Hepatitis B virus vaccine in chronic kidney disease: improved immunogenicity by adjuvants? A meta-analysis of randomized trials

BACKGROUND

Patients with chronic kidney disease typically show an impaired immune response to hepatitis B virus vaccine compared with healthy individuals. A variety of inherited or acquired factors have been implicated in this diminished response. Some authors suggested a benefit with adjuvantation to improve the immunogenicity of existing HBV vaccines.

AIM

To evaluate the efficacy and safety of adjuvantation for hepatitis B virus vaccine in patients with chronic kidney disease.

METHODS

Only prospective, randomized clinical trials (RCTs) were included. We used the random effects model of DerSimonian and Laird with heterogeneity and subgroups analyses. The primary end-point of interest was the seroprotection rate after HBV vaccination with recombinant vaccine plus adjuvants (study group) versus recombinant vaccine alone (control group).

RESULTS

We identified ten studies involving 1228 unique patients with chronic kidney disease. Pooling of study results did not show a significant increase in seroprotection rate among study (HBV recombinant vaccine plus adjuvants) versus control (HBV recombinant alone) patients; the pooled odds ratio of seroprotection rate was 1.47 (95% CI: 0.88; 2.46, NS). The pooled OR for seroresponse rate after HBV vaccine (adjuvanted recombinant vaccine versus recombinant vaccine alone) did not change in the subgroup of studies based on novel adjuvant systems (i.e., HBV-AS04 or HBV-AS02), the pooled OR was 2.22 (95% CI, 0.72; 6.78), NS. Q-test for heterogeneity being 10.819 (P=0.004).

CONCLUSIONS

Our meta-analysis showed that adjuvanted hepatitis B vaccine did not significantly improve the seroprotection rate in patients with renal insufficiency. These results do not support adjuvantation as an approach to increase the immunogenicity of existing recombinant vaccines towards HBV in this high-risk population.

Hepatitis C virus and the immunological response to hepatitis B virus vaccine in dialysis patients: meta-analysis of clinical studies

It is well known that the seroconversion rate of patients following hepatitis B virus (HBV) vaccination is lower in uraemic than healthy subjects. A variety of inherited or acquired factors have been implicated in this diminished response, and the high prevalence of hepatitis C virus (HCV) infection among patients on maintenance dialysis has been suggested to play a role. However, the impact of HCV on the immune response to HB vaccine in patients receiving long-term dialysis is not entirely understood. Here, we evaluate the influence of HCV infection on the immunological response to HBV vaccine in dialysis population by performing a systematic review of the literature with a meta-analysis of clinical studies.We used the random-effects model of DerSimonian and Laird with heterogeneity and sensitivity analyses. The end-point of interest was the rate of patients showing seroprotective anti-hepatitis B titres at completion of HBV vaccine schedule among HCV-positive versus HCV-negative patients on chronic dialysis. We identified eight studies involving 520 unique patients on long-term dialysis. Aggregation of study results did not show a significant decrease in response rates among HCV-infected versus noninfected patients [pooled odds ratio = 0.621 (95% CI, 0.285; 1.353)]. The P-value was 0.007 for our test of study heterogeneity. Stratified analysis in various subgroups of interest did not meaningfully change our results. Our meta-analysis showed no association between immunological response to hepatitis B vaccine and HCV infection in individuals on long-term dialysis. These results support the use of recombinant vaccine against hepatitis B in patients on regular dialysis with HCV infection.

Immunogenicity of hepatitis B vaccine among hemodialysis patients: effect of revaccination of non-responders and duration of protection

BACKGROUND

Hepatitis B vaccination is recommended for patients on hemodialysis, however, seroprotection after a primary vaccine series is suboptimum. Limited data are available on the effect of revaccination of non-responders and on persistence of immunity in this population.

METHODS

Hepatitis B vaccine (40 μg/dose) was given to 77 susceptible patients on hemodialysis (0, 1, and 6 month schedule). Levels of hepatitis B surface antibody (anti-HBs) were tested ≥ 28 days after the third dose was administered, and non-responders revaccinated with an additional 3-dose series. Vaccine responders (anti-HBs ≥10 mIU/mL) were re-tested every 6 months and booster doses given as needed. Kaplan-Meier survival curve was used to estimate the probability of maintaining protective antibody level. Cox-proportional hazards models were used to assess the association between time to loss of protective antibody levels and certain explanatory variables.

RESULTS

Overall primary vaccine-induced response was 79.2% (95% CI 68.2%, 87.3%), including 49/77 (63.6%; 95% CI 51.8%, 74.7%) patients who received the initial primary hepatitis B vaccine series and 12/21 (57.1%; 95% CI 34.4%, 77.4%) non-responders who were revaccinated with an additional series. Among weak responders (anti-HBs level 10.0-99.9 mIU/mL), protective antibody levels persisted in 44% for 12 months post-vaccination; whereas among strong responders (anti-HBs level ≥100 mIU/mL), protective antibody levels persisted in 92% for 12 months, and 68% for 24 months post-vaccination. A weak post-vaccination response increased the risk of losing protective antibody levels (adjusted hazard ratio, 9.7; 95% confidence interval, 3.5-28.5; p<0.0001).

CONCLUSION

Revaccinating patients undergoing hemodialysis who do not respond to a primary vaccine series substantially increases the pool of protected patients. The threshold for defining hepatitis B vaccine-induced immunity should be revisited in this patient population to maximize the duration of protection.

Meta-analysis: the impact of diabetes mellitus on the immunological response to hepatitis B virus vaccine in dialysis patients

BACKGROUND

Patients on maintenance dialysis typically show a suboptimal immune response to hepatitis B virus vaccine compared with the non-uraemic population. A variety of inherited or acquired factors have been implicated in this diminished response. It is well known that patients with diabetes mellitus have a compromised immune system, and diabetic nephropathy is an important cause of chronic kidney disease. However, the impact of diabetes mellitus on the immune response to HBV vaccine in patients receiving long-term dialysis remains unclear.

AIM

To evaluate the influence of diabetes mellitus on the immune response to HBV vaccine in dialysis population by performing a systematic review of the literature with a meta-analysis of clinical studies.

METHODS

We used the random effects model of DerSimonian and Laird with heterogeneity and sensitivity analyses. The end-point of interest was the rate of patients showing seroprotective antibody against hepatitis B surface antigen at completion of vaccine schedule in the diabetic vs. the nondiabetic dialysis individuals.

RESULTS

We identified 12 studies involving 1002 unique patients on long-term dialysis. Aggregation of study results showed a significant decrease in response rates among the diabetic vs. the nondiabetic patients [pooled odds ratio=0.52 (95% CI 0.38-0.71)]. The P-value was 0.29 for our test of study heterogeneity. Stratified analysis in various subgroups of interest did not meaningfully change our results.

CONCLUSIONS

Our meta-analysis showed a clear association between diabetes mellitus and impaired response to hepatitis B virus vaccine in individuals on long-term dialysis. Such a relationship is biologically plausible. Vaccination schedules with adapted vaccine doses and frequent serum testing for loss of immunity against hepatitis B virus should be considered in patients on maintenance dialysis with diabetes mellitus.

Antibody response following hepatitis B vaccination in peritoneal dialysis patients: does normalized urea clearance matter?

OBJECTIVES

Data on the factors that contribute to the antibody response to hepatitis B virus vaccination in peritoneal dialysis patients are scarce. The current study was conducted on a group of peritoneal dialysis patients to learn how the response to hepatitis B virus vaccination varies according to the patient's clearance of urea normalized to total body water (Kt/V).

METHODS

A convenience sample of 33 peritoneal dialysis patients (13 women and 20 men, with a mean age of 49 ± 12 years) was administered double doses (20 μg IM in each deltoid muscle) of recombinant hepatitis B vaccine at 0, 1, 2, and 6 months. Response to immunization was measured at one to three months after the final dose of vaccine. The subjects were divided into groups according to the level of antibodies to hepatitis B surface antigen (anti-HBs), including non-responders ( < 10 IU/L), weak responders (10-100 IU/L), and good responders ( > 100 IU/L).

RESULTS

Among non-responders, weak responders, and good responders, significant differences were found in age (54 ± 12 vs. 56 ± 9 vs. 45 ± 12 years, respectively; p = 0.049) and recombinant human erythropoietin use (20 vs. 29 vs. 76%, respectively; p = 0.016). No significant differences in weekly total Kt/V (p = 0.704), weekly peritoneal Kt/V (p = 0.064) and residual glomerular filtration rate (p = 0.355) were found across the three groups.

CONCLUSIONS

Delivered clearance measured by weekly peritoneal Kt/V and total clearance measured by weekly total Kt/V did not predict the response to hepatitis B virus vaccination in patients on peritoneal dialysis.

Immunogenicity and safety of an investigational AS02(v)-adjuvanted hepatitis B vaccine in patients with renal insufficiency who failed to respond or to maintain antibody levels after prior vaccination: results of two open, randomized, comparative trials

An investigational AS02(v)-adjuvanted hepatitis B (HB-AS02) was compared with a licensed conventional recombinant hepatitis B vaccine (HBVAXPRO™; Sanofi Pasteur MSD, Lyon, France) in pre-dialysis, peritoneal dialysis and hemodialysis patients aged ≥18 years who had failed either to respond to prior vaccination with a conventional hepatitis B vaccine (Study A; n=251) or to maintain protective antibody concentrations after prior hepatitis B vaccination (Study B; n=181). These were open, randomized, comparative trials. Mean (range) age was 65.9 (31-92) and 64.6 (29-92) years in the two studies, respectively. In Study A, two doses of HB-AS02 given one month apart were found to be superior to two doses of the licensed vaccine in terms of seroprotection rate (76.9% versus 37.6%) and anti-HBs geometric mean antibody concentration (GMC; 139.3 versus 6.9mIU/ml), with antibody concentrations ≥100mIU/ml in 61.1% and 15.4% of subjects in the two groups, respectively. In Study B, one month after administration of a single booster dose, seroprotection rates were 89.0% in the HB-AS02 group and 90.8% in the licensed vaccine group, 81.3% and 60.9% of subjects had antibody concentrations ≥100mIU/ml, and anti-HBs GMCs were 1726.8 and 189.5mIU/ml. HB-AS02 was found to be more reactogenic than the licensed vaccine. In summary, the investigational HB-AS02 vaccine induced higher seroprotection rates and anti-HBs GMCs than a licensed conventional hepatitis B vaccine in uremic patients who had failed to respond or to maintain protective antibody titers after prior hepatitis B vaccination.

Meta-analysis: levamisole improves the immune response to hepatitis B vaccine in dialysis patients

BACKGROUND

Patients undergoing maintenance dialysis often fail to mount protective antibodies to hepatitis B virus surface antigen (HBsAg) following vaccination against hepatitis B virus (HBV). Some authors have suggested that levamisole improves immune response to HBV vaccine in dialysis population. However, consistent information on this issue does not exist.

AIM

To evaluate efficacy and safety of levamisole as adjuvant to hepatitis B virus (HBV) vaccine in dialysis patients by performing a systematic review of the literature with a meta-analysis of clinical trials.

METHODS

We used the random-effects model of DerSimonian and Laird, with heterogeneity and sensitivity analyses. Only trials comparing the seroresponse rate in study subjects (levamisole plus HBV vaccine) vs. controls (HBV vaccine alone) were included. The end point of interest was the rate of patients showing seroprotective anti-hepatitis B titres at completion of HBV vaccine schedule in study vs. control groups.

RESULTS

We identified four studies involving 328 unique patients on regular dialysis. Only prospective, randomized clinical trials (RCTs) were included. Pooling of study results showed a significant increase in response rates among study (levamisole plus HBV vaccine) vs. control (HBV vaccine alone) patients; the pooled Odds Ratio was 2.432 (95% Confidence Intervals, 1.34; 4.403), P = 0.002. No study heterogeneity was found. These results did not change in various subgroups of interest.

CONCLUSIONS

Our meta-analysis showed that levamisole significantly improves immune response to hepatitis B vaccine in dialysis population. The limited number of patients precluded more conclusions.

Long-term serologic follow-up of isolated hepatitis B core antibody in HIV-infected and HIV-uninfected women

BACKGROUND

Isolated antibody to hepatitis B core antigen (anti-HBc) is a common serologic finding in persons infected with human immunodeficiency virus (HIV), but the outcome and clinical significance are uncertain.

METHODS

We performed repeated hepatitis B virus (HBV) serologic tests on women who participated in the Women's Interagency HIV Study and who had isolated anti-HBc at study entry.

RESULTS

Repeated serologic tests were performed for 322 women (282 HIV-infected and 40 HIV-uninfected) at a median of 7.5 years after study entry. Seventy-one percent of women retained isolated anti-HBc serologic status, 20% acquired antibody to hepatitis B surface antigen (anti-HBs), and 2% acquired hepatitis B surface antigen (HBsAg). In unadjusted analysis, increasing age, injection drug use, and hepatitis C viremia were negatively associated with acquisition of anti-HBs. For HIV-infected women, predictors of acquisition of anti-HBs were an increase in CD4 cell count and the use of highly active antiretroviral therapy (HAART). Receipt of drugs with activity against HBV and self-reported HBV vaccination did not predict anti-HBs acquisition. In the multivariable regression model, HAART use remained a significant predictor of anti-HBs acquisition, whereas women with hepatitis C viremia were more likely to retain isolated anti-HBc serologic status.

CONCLUSIONS

Isolated anti-HBc status remained stable over time for the majority of women, especially women with chronic hepatitis C virus infection. Development of anti-HBs was predicted by HAART use and an increase in CD4 cell count. We conclude that a proportion of HIV-infected women with isolated anti-HBc have prior natural HBV infection with anti-HBs that is at an undetectable level because of immune dysfunction. Isolated anti-HBc in the presence of chronic hepatitis C virus infection may be attributable to a different phenomenon, such as dysfunctional antibody production.

Hepatitis B vaccination: The key towards elimination and eradication of hepatitis B

Hepatitis B virus infection is a global health problem. Worldwide, about 360 million people are chronically infected with the virus. They continue to spread the virus to others and are themselves at risk of chronic liver diseases and hepatocellular carcinoma. The infection can now be treated by antivirals or interferons and the transmission route can be interrupted. Nevertheless, the most effective means is to immunize all susceptible individuals, especially young children, with safe and efficacious vaccines. The combined efforts of vaccination, effective treatment and interruption of transmission make elimination of the infection plausible and may eventually lead to eradication of the virus. Because hepatitis B vaccination has a key role in the control of hepatitis B, properties of this vaccine, its effectiveness in pre-exposure and post-exposure settings, duration of protection after vaccination and the need of booster doses are discussed. Mass hepatitis B vaccination in children decreases the carriage of the virus, and the diseases associated with acute and chronic infection, including hepatocellular carcinoma. Challenges that need to be solved to expand mass vaccination, and the strategies towards elimination and eventual eradication of hepatitis B in the world are also discussed.

Bivalent inactivated hepatitis A and recombinant hepatitis B vaccine

Hepatitis A and B remain serious global public health problems. Monovalent vaccines against hepatitis A and B have been available for many years. Since 1996, licenses have been gradually introduced for different formulations and immunization schedules of the first combined vaccines against both diseases. Twinrix Adult (with conventional and accelerated schedules) is available for the immunization of individuals aged 16 years or older in Europe and 18 years or older the USA. Twinrix Pediatric, with its three-dose schedule, and AmBirix, with its two-dose schedule, are licensed in Europe for ages 1-15 years. These vaccines offer a single injection for satisfactory protection against hepatitis A and B and an excellent safety and reactogenicity profile in comparison with monovalent vaccines. This article focuses on immunogenicity of the vaccines and proposes expert opinion and future directions in this field.

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.

Safety and immunogenicity of a new hepatitis B vaccine for the protection of patients with renal insufficiency including pre-haemodialysis and haemodialysis patients

BACKGROUND

High susceptibility to infections including the hepatitis B virus (HBV) causes increased morbidity and mortality in patients with end stage renal disease. HBV vaccination is recommended for all patients undergoing dialysis; however, antibody response is much lower than in healthy individuals.

OBJECTIVE

This review discusses the clinical experience with HBV vaccine with a novel adjuvant system among dialysed patients.

METHOD

A new adjuvanted HBV vaccine (Fendrix(), GlaxoSmithKline Biologicals, Rixensart, Belgium) contains as active substance 20 microg recombinant hepatitis B surface antigen produced in Saccharomyces cerevisiae and the novel adjuvant system composed of aluminum salt and 3-O-desacyl-4'-monophosphoryl lipid A (AS04).

CONCLUSION

HBV-AS04 vaccine has a good safety profile with clinically acceptable reactions similar to standard HBV vaccines and has elicited earlier antibody response and higher antibody titres in pre and haemodialysis patients as compared with four double doses of standard HBV vaccine.

A new adjuvant improves the immune response to hepatitis B vaccine in hemodialysis patients

Prehemodialysis and hemodialysis patients are at an increased risk of hepatitis B infection and have an impaired immune response to hepatitis B vaccines. We evaluated the immune response to the new adjuvant of hepatitis B vaccine AS04 (HBV-AS04) in this population. We measured antibody persistence for up to 42 months, and the anamnestic response and safety of booster doses in patients who were no longer seroprotected. The primary vaccination study showed that HBV-AS04 elicited an earlier antibody response and higher antibody titers than four double doses of standard hepatitis B vaccine. Seroprotection rates were significantly higher in HBV-AS04 recipients throughout the study. The decline in seroprotection over time was significantly less in the HBV-AS04 group with significantly fewer primed patients requiring a booster dose over the follow-up period. Solicited/unsolicited adverse events were rare following booster administration. Fifty-seven patients experienced a serious adverse event during the follow-up; none of which was vaccine related. When HBV-AS04 was used as the priming immunogen, the need for a booster dose occurred at a longer time compared to double doses of standard hepatitis B vaccine. Hence, in this population, the HBV-AS04 was immunogenic, safe, and well-tolerated both as a booster dose after HBV-AS04 or standard hepatitis B vaccine priming.

Viral interaction and clinical implications of coinfection of hepatitis C virus with other hepatitis viruses

Coinfection with other hepatitis viruses modifies the viral profile in serum and leads to more liver damage and more rapid progression during the course of hepatitis C virus infection. The viral interference is not only carried out by virus-virus or by virus-cell interactions but also by an enhanced immune response. A superinfecting viral infection does not crossactivate protective immune responses to the pre-existing virus albeit the latter can become undetectable. The induced cytokine stimulation might enhance the hepatic inflammation. Moreover, hepatitis B virus coinfection increases the risk of development of hepatocellular carcinoma in hepatitis C virus patients through common necro-inflammatory pathways or by direct oncogenic activity of hepatitis B virus. Viral interaction also complicates the management of the coinfection because hepatitis C virus impairs the humoral response to hepatitis A virus and hepatitis B virus vaccines, and because pharmacological suppression of hepatitis C virus endangers dually infected patients with reactivation of coinfected hepatitis B virus. Optimized strategies and follow-up are thus necessary in the treatment of infection with multiple viruses. It seems thus necessary to look for markers of hepatitis B virus and/or hepatitis D virus infection in chronic hepatitis patients positive for hepatitis C virus antibodies but negative for hepatitis C virus RNA, and equally well to search for hepatitis C virus RNA in HBsAg-negative/anti-HBc-positive patients with a low level of serum hepatitis B virus DNA.

Meta-analysis: the adjuvant role of granulocyte macrophage-colony stimulating factor on immunological response to hepatitis B virus vaccine in end-stage renal disease

BACKGROUND

Chronic dialysis patients often fail to produce protective antibodies to hepatitis B virus surface antigen after vaccination towards hepatitis B virus (HBV). Several authors suggested a benefit for granulocyte macrophage-colony stimulating factor (GM-CSF) as an adjuvant to HBV vaccination in patients with end-stage renal disease (ESRD). However, consistent information is still lacking.

AIMS

To evaluate efficacy and safety of GM-CSF as adjuvant to hepatitis B vaccine in patients with ESRD by performing a systematic review with a meta-analysis of prospective controlled clinical trials (CCTs).

METHODS

Only trials comparing the seroresponse rate in study (GM-CSF plus HBV vaccine) versus control (HBV vaccine alone) patients were included. We used the random effects model of DerSimonian and Laird, with heterogeneity and sensitivity analyses. The end-point of interest was the rate of patients showing seroprotective anti-hepatitis B titers at completion of HBV vaccine schedule in study versus control groups.

RESULTS

We identified seven studies involving 187 unique patients with ESRD. Only prospective CCTs were included. Pooling of study results showed a significant increase in response rates among study (GM-CSF plus HBV vaccine) versus control (HBV vaccine alone) patients (pooled Odds Ratio, 4.63 [95% Confidence Intervals, 1.42; 15.14]). The P-value was 0.02 for our test of study heterogeneity.

CONCLUSIONS

Our meta-analysis showed improved seroprotection rates with HBV vaccine after GM-CSF administration.

Overview of vaccination in chronic kidney disease

Infections are a major cause of death in end-stage renal disease (ESRD) patients, second only to cardiovascular disease, and also contribute to significant morbidity in patients with earlier stages of chronic kidney disease (CKD). Vaccines are a strategy to attempt to reduce morbidity related to infections. Patients with CKD and ESRD may not respond as well to vaccines as patients without kidney failure, but adequate seroresponse with standard or augmented regimens for vaccinations against influenza, hepatitis B, pneumococcus, and varicella have been documented. Influenza, in particular, seems to provide adequate protection with standard dosing regimens. Despite somewhat reduced effectiveness of certain vaccines in patients with CKD, there is emerging evidence of benefit to vaccination in these populations. However, vaccination rates are relatively low. Given the accumulating evidence of benefit, continuing quality improvement programs focused on increasing vaccination rates in patients with all levels of CKD are needed.

Meta-analysis: the adjuvant role of thymopentin on immunological response to hepatitis B virus vaccine in end-stage renal disease

BACKGROUND

It has been calculated that 30-40% of dialysis patients fail to produce antibodies to HBsAg antigen after vaccination towards hepatitis B virus. Several authors have reported on the benefit of thymopentin (TP5) as adjuvant to vaccine against hepatitis B virus in patients receiving regular dialysis. However, consistent information on this issue is still lacking.

AIMS

To evaluate efficacy and safety of thymopentin as adjuvant to hepatitis B vaccine in dialysis patients by performing a systematic review with a meta-analysis of clinical trials.

METHODS

We used the random effects model of DerSimonian and Laird, with heterogeneity and sensitivity analyses.

RESULTS

We identified 11 studies involving 272 unique patients with end-stage renal disease. Only prospective, controlled trials were included. Pooling of study results did not show a significant increase in seroresponse rate among study (thymopentin plus hepatitis B virus vaccine) vs. control (hepatitis B virus vaccine alone) patients; the pooled odds ratio of failure to respond to hepatitis B virus vaccine was 0.677 (95% confidence intervals: 0.285-1.605); no heterogeneity was found (P = 0.0001). Thymopentin significantly improved the seroresponse rate in the subgroup of trials based on greater thymopentin doses (OR: 0.184; 95% CI: 0.085-0.398).

CONCLUSIONS

Our meta-analysis showed that thymopentin significantly improved the seroresponse rate towards hepatitis B vaccine only in dialysis patients treated with higher thymopentin doses. The limited number of patients precluded definitive conclusions.

Meta-analysis: the dialysis mode and immunological response to hepatitis B virus vaccine in dialysis population

BACKGROUND

Patients on maintenance dialysis typically show a suboptimal immune response to hepatitis B virus vaccine compared with the non-uraemic population. Some authors have claimed that dialysis mode has an impact on the immune response to hepatitis B virus vaccine but consistent information is lacking on this issue.

AIM

To evaluate the relationship between dialysis mode and immune response to hepatitis B vaccine in dialysis population by performing a systematic review with a meta-analysis of clinical trials.

METHOD

We used the random effects model of DerSimonian and Laird; sources of heterogeneity in effect estimates were explored by performing sensitivity analyses.

RESULTS

The relative risk of failure to respond to hepatitis B vaccine among patients who underwent maintenance haemodialysis vs. peritoneal dialysis was the end point of interest. We identified 14 clinical trials involving 1211 unique patients on maintenance dialysis. Pooling of study results did not show a significant decreased risk of response to hepatitis B vaccine among haemodialysis patients (overall risk ratio: 1.0, 95% confidence intervals: 0.92-1.1). The P-value was 0.13 for our test of study heterogeneity.

CONCLUSION

There is no significant link between dialysis mode and seroresponse to hepatitis B virus vaccine in dialysis population.

Immunogenicity and safety of an adjuvanted hepatitis B vaccine in pre-hemodialysis and hemodialysis patients

BACKGROUND

Due to their impaired immune system, patients with renal insufficiency have a suboptimal response to hepatitis B (HB) vaccination and frequent boosters are needed to maintain protection. GlaxoSmithKline Biologicals has developed a HB vaccine containing a new adjuvant system AS04 for use in this immunocompromised patient population.

METHODS

In an open, randomized clinical trial conducted in pre-hemodialysis (documented creatinine clearance < or =30 mL/min) and hemodialysis patients, over 15 years of age and naïve for HB, the immunogenicity and safety of single doses of HB-AS04 (Fendrix, GlaxoSmithKline Biologicals) were compared to double doses of commercially available HB vaccine (Engerix, GlaxoSmithKline Biologicals) administered at 0, 1, 2, and 6 months, and followed-up for 36 months.

RESULTS

The HB-AS04 vaccine elicited a more rapid onset of protection than the currently licensed vaccine for this particular population, with 74% versus 52% of subjects seroprotected at month 3. After the vaccination course, seroprotection rates increased to 91% versus 84% in the HB-AS04 and standard vaccine groups, respectively. Differences persisted up to 36 months post-vaccination (73% vs. 52%, respectively). Antibody concentrations were higher following the HB-AS04 vaccine at all post-vaccination time points. During the follow-up, significantly fewer subjects primed with the HB-AS04 vaccine needed a booster dose as a consequence of anti-HBs loss below seroprotective levels (11/62 subjects in the HB-AS04 group vs. 22/57 subjects in the standard vaccine group, respectively, P = 0.014). The HB-AS04 was more locally reactogenic than the standard immunization regimen, with pain at the injection site occurring with 41% of HB-AS04 doses versus 19% of standard vaccine doses. The occurrence of grade 3 pain was less than 1% in both groups and all events resolved within the 4-day follow-up period.

CONCLUSION

The improved immunogenicity profile and clinically acceptable reactogenicity of HB-AS04 vaccine are of key importance to provide a more rapid, enhanced, and longer seroprotection to these immunocompromised patients at risk for HB infection.

Hepatitis B vaccination in human immunodeficiency virus-infected adults receiving hemodialysis

BACKGROUND

The Centers for Disease Control and Prevention (CDC) recommends hepatitis B virus (HBV) immunization for all hemodialysis (HD) patients because they are at high risk of infection. Several studies have shown that the development of protective antibody titers after HBV vaccination is much lower in HD patients. We hypothesized that human immunodeficiency virus (HIV) infection in patients with end-stage renal disease (ESRD) would further impair the immune response to hepatitis B vaccination.

METHODS

We performed a retrospective cohort study of patients undergoing long-term hemodialysis from 1990 to 2002 at the United States-based dialysis facilities of Gambro Corporation, North America. The response rate defined as an increase in anti-HBs levels >/=10 mIU/L after a month of the third dose of HBV vaccination was determined in HIV-infected and a randomly selected group of ESRD patients. The demographic information, laboratory data, and hepatitis B surface antibody (anti-HBs) titers were recorded from the Gambro Corporation database on these patients.

RESULTS

Of the 347 adult HIV ESRD patients, 116 received three doses of recombinant hepatitis B vaccination. Seventy percent were male, and the majority (86%) were black. Of the 116 patients who received three doses of HBV vaccination, 62 (53.4%) developed protective antibody titers. This was comparable to the response rate of 50.4% in the randomly selected 220 non-HIV hemodialysis patients. Among HIV ESRD patients, the mean hemoglobin (Hgb) was higher in patients who developed protective antibody titers (Hgb 11.61 +/- 2 vs. 10.55 +/- 1.86, P value <0.01). On multivariate logistic regression analysis, higher Hgb was associated with protective antibody titers (odds ratio: 1.34, 95% CI 0.99-1.72). Seventy percent of the HIV-infected responders maintained protective antibody titers 6 months after vaccination.

CONCLUSION

Hepatitis B vaccination should be offered to all HIV-infected ESRD patients because over half of the patients with HIV and ESRD can develop protective antibodies.

Meta-analysis: the effect of age on immunological response to hepatitis B vaccine in end-stage renal disease

BACKGROUND

Patients on maintenance dialysis typically show a suboptimal immune response to hepatitis B virus vaccine compared with the non-uraemic population. A variety of inherited or acquired factors have been implicated in this diminished response. Age-associated changes in immune status may contribute to decreased vaccine efficacy in older individuals although contradictory results have been reported in individuals with normal kidney function.

AIMS

To evaluate the relationship between age and immune response to hepatitis B vaccine in patients with end-stage renal disease by performing a systematic review of the literature with a meta-analysis of clinical trials.

METHOD

We used the random effects model of DerSimonian and Laird; sources of heterogeneity in effect estimates were explored by performing sensitivity analyses.

RESULTS

We identified 17 clinical trials (1800 unique patients); six (35%) were controlled studies. Pooling of study results demonstrated a significantly decreased risk of response to hepatitis B vaccine among older dialysis patients (overall risk ratio: 0.74; 95% confidence intervals: 0.70-0.79). The P-value was 0.0139 for our test of study heterogeneity. A lowered risk of response to hepatitis B vaccine persisted after exclusion of trials based on plasma-derived vaccines; it was present even when 'older' individuals were defined as being as 50 years (RR: 0.85, 95% CI: 0.75-0.96) or more (cut-off 60 years RR: 0.75; 95% CI: 0.66-0.85). An effect of age on seroprotection rate was present in all clinical reports, irrespective of the geographic origin of the study group: Europe (RR: 0.76; 95% CI: 0.70-0.83) North America (RR: 0.67; 95% CI: 0.60-0.74) or other countries (RR: 0.83; 95% CI: 0.71-0.97). Additional doses of vaccine did not appear to have an impact on RR of response by age.

CONCLUSIONS

Our meta-analysis showed a clear association between older age and impaired response to hepatitis B virus vaccine in end-stage renal disease patients. Such a relationship is biologically plausible. Vaccination schedules with adapted vaccine doses and frequent serum testing for loss of immunity against hepatitis B virus are recommended in elderly patients on maintenance dialysis.

Anti-HBs cellular immune response in kidney recipients before and 4 months after transplantation

Patients with renal failure represent a population at risk for hepatitis B, since only 50 to 60% of them develop protective humoral responses after vaccination. As this could be due to an altered regulation of cellular immune responses, the objectives of the present study were to evaluate the proliferative abilities of lymphocytes from patients with chronic renal failure after stimulation in vitro with a mitogen (pokeweed mitogen [PWM]) or HBsAg. In order to differentiate between the immunodeficiency associated with renal failure and that due to immunosuppression posttransplantation, the same subjects were tested before and 4 months after kidney transplantation. The lymphoproliferation assay used was performed by flow cytometry, which is based on sequential analysis of the cell cycle and which allows analysis of cytokine production. Serologically, the group of 36 patients tested comprised 22% nonresponders, 30% poor responders, and 48% responders. Lymphocyte growth was observed for all patients after stimulation with PWM, indicating that these cells had the capacity to proliferate in vitro. The level of lymphoproliferation in response to PWM was significantly reduced after transplantation, yet both before and after transplantation, all serologic nonresponders developed cellular responses to at least two vaccines. No correlation between humoral and cellular responses was shown. Proliferating cells were lymphocytes, which mostly secreted interleukin 4 (IL-4) and IL-10 for the three serologic groups. This study suggests that even when repeated vaccination fails to induce significant antibody levels in patients with renal failure, specific HBs cellular responses develop, and these may prove to be efficient in protecting these patients against hepatitis B.

Stage of chronic kidney disease predicts seroconversion after hepatitis B immunization: earlier is better

BACKGROUND

Hepatitis B virus (HBV) infection remains a concern in dialysis populations, and vaccination programs have been less successful than those in the general population. Reasons for poor response include malnutrition, uremia, and the generalized immunosuppressive state of patients with chronic kidney disease (CKD). This prospective cohort study evaluated factors impacting on the effectiveness of a vaccination program before dialysis therapy initiation, including level of kidney function.

METHODS

All patients receiving care in the Kidney Function Clinic (St Paul's Hospital, Vancouver, Canada) were screened for previous HBV infection or vaccination. Those who were marker negative were administered a standardized hepatitis B vaccination schedule recommended for patients with CKD. The primary outcome measure, seroconversion, is defined as hepatitis B surface antibody titer greater than 10 IU 3 months after completion of the vaccination schedule.

RESULTS

The study population of 165 patients included 64% men with a mean age of 60 years, mean serum creatinine level of 3.4 +/- 1.5 mg/dL (300 +/- 133 micromol/L), and median estimated glomerular filtration rate (GFR) of 20 mL/min (interquartile range, 14 to 20). Seroconversion rate was 82%. Multivariate analyses showed the independent predictive value of level of GFR. The model showed that patients with the lowest level of kidney function and who were older and had diabetes were less likely to seroconvert (P < 0.05).

CONCLUSION

This is the largest study to show in a well-characterized cohort that patients with higher GFR levels are more likely to respond to hepatitis B vaccination programs with seroconversion, independent of other factors. Future studies will explore specific mechanisms to explain this phenomenon.

The Value of Vaccination in Chronic Kidney Disease

There has been much attention directed toward the high mortality of patients with end-stage renal disease (ESRD), with much of the focus on cardiovascular disease. However, infectious disease is the second most common cause of death in late-stage chronic kidney disease (CKD) patients. Although CKD patients are immunocompromised, some vaccines such as influenza, retain their efficacy and reduce infection rates with a standard immunization schedule. Other vaccines, such as hepatitis B and pneumococcal vaccines, require more frequent and/or higher doses to produce and maintain protective antibody levels. Attention has recently been given to the efficacy of influenza vaccination in ESRD patients in reducing morbidity and mortality. Centers with vaccination protocols have demonstrated reduced infection rates and resultant decreased morbidity and mortality. It could be extrapolated from this that widespread vaccination would reduce the total cost of ESRD patient care, and potentially improve patient well-being. However, vaccination appears to be underutilized in CKD patients, and it is a readily available intervention to improve outcomes.

Intramuscular versus intradermal administration of anti-hepatitis B vaccine in non-cirrhotic hepatitis C patients

Intradermal vaccination has been proposed as an alternative for the administration of anti-hepatitis B vaccine. Patients (n=66) with chronic viral hepatitis C without cirrhosis were randomised into two groups (intramuscular, n=38; and intradermal, n=28) for prospective immunisation with 20 microg recombinant vaccine, using an ultra-rapid schedule (doses at 0, 15 and 30 days). Sero-conversion (antibody level >/=10 mU/ml) in the intramuscular group was reached by 20, 40 and 72% of patients at days 15, 30 and 60 compared to 4, 8 and 36% for the intradermal group (P=0.010 at day 60). Additionally, levels rose more rapidly in the intramuscular group (P=0.004). Our results do not support the use of intradermal route of immunisation against HBV in HCV patients.