Durability of Antibody Response Against the Hepatitis B Virus in Kidney Transplant Recipients: A Proposed Immunization Guideline From a 3-Year Follow-up Clinical Study

Hepatitis B Vaccine Compliance, Serologic Response, and Durability in Adult Thoracic Organ Transplant Recipients

INTRODUCTION

Hepatitis B virus (HBV) vaccination is recommended for solid organ transplant (SOT) candidates. However, there is a lack of data on the HBV vaccine compliance, serologic response, and durability of HBV seroprotection in thoracic organ transplantation recipients.

METHODS

We conducted a retrospective study of adult thoracic organ (heart and lung) transplant candidates who received HBV vaccination at Mayo Clinic sites in Minnesota, Arizona, and Florida between January 2018 and August 2023. Conventional recombinant hepatitis B vaccine (Recombivax HB) was used before 2020, and Heplisav-B was preferred after 2020. HBV seroprotection was defined as hepatitis B surface antibody (HBsAb) ≥ 10 IU/L. Furthermore, we compared characteristics between recipients who maintained HBV seroprotection and those who lost HBV seroprotection (HBsAb < 10 IU/L) at 30 days posttransplantation (D30).

RESULTS

Among 922 candidates who were eligible for HBV vaccination, 430 (47%) completed the HBV vaccine series. Patients receiving Heplisav-B were more likely to complete the series than Recombivax HB (81% vs. 60%, p < 0.001) and Heplisav-B had a higher seroprotection rate than Recombivax HB (75% vs. 64%, p = 0.023). Multivariate logistic regression analysis identified receiving Heplisav-B as an independent predictor for HBV seroprotection (adjusted odds ratio [aOR] 1.723; 95% confidence interval [CI] 1.056-2.810; p = 0.029). A total of 145 thoracic organ transplant recipients achieved HBV seroprotection at the date of transplantation. Loss of HBV seroprotection occurred in 38 (26%) patients at D30. Multivariate logistic regression analysis identified two predictors for HBV seroprotection loss at D30: age ≥ 60 years (aOR, 2.503; 95% CI 1.026-6.107; p = 0.044), and pretransplant HBsAb level between 10 and 100 IU/L (aOR, 18.575; 95% CI 5.211-66.209; p < 0.001).

CONCLUSIONS

Although less than half of thoracic organ transplant candidates completed HBV vaccine series pretransplant, Heplisav-B provided a higher vaccine completion rate and seroprotection than the 3-dose Recombivax HB. Clinicians should also be aware of the increased loss of HBV seroprotection in thoracic organ transplant recipients with age ≥ 60 years and pretransplant HBsAb between 10 and 100 IU/L. Assessment of seroprotection after HBV vaccination should be prioritized during the pretransplant period.

Report on post-transplantation cancer in southeast Asia from the Thai kidney transplantation cohort

Post-transplantation cancer is a significant cause of mortality among kidney transplant recipients (KTR). The incidence of post-transplantation cancer varies based on geographic region and ethnicity. However, data on KTR from South East Asia, where characteristics differ from other parts of Asia, is lacking. We conducted a retrospective cohort study at a transplant center in Thailand to investigate the incidence of post-transplantation cancer and mortality rates. Factors associated with post-transplantation cancer and patient outcomes were analyzed using competing-risks regression. The study included 1156 KTR with a post-transplant follow-up duration of 5.1 (2.7-9.4) years. The age- and sex-adjusted incidence rate of post-transplant cancer was highest for urothelial cancer (6.9 per 1000 person-years), which also resulted in the highest standardized incidence ratio (SIR) of 42.5 when compared to the general population. Kidney cancer had the second-highest SIR of 24.4. Increasing age was the factor associated with an increased risk of post-transplant cancer (SHR 1.03; 95% CI 1.01-1.05). Human leukocyte antigen (HLA) DR mismatch was associated with a decreased risk of post-transplant cancer (SHR 0.72; 95% CI 0.52-0.98). Post-transplantation cancer was significantly associated with patient mortality (HR 3.16; 95% CI 2.21-4.52). Cancer significantly contributes to KTR mortality, and the risk profile for cancer development in Thai KTRs differs from that of Western and most Asian counterparts. Further research is essential to explore appropriate screening protocols for countries with high rates of urothelial and kidney cancer, including Thailand.

Size Matters! Anti-HBs Titer and HBV Reactivation During Anti-TNF Therapy

BACKGROUND AND AIMS

We and others have previously described that hepatitis B surface antibody (anti-HBs) seems to protect against clinically significant HBV reactivation in cohort studies of patients undergoing anti-tumor necrosis factor (TNF) therapy. However, there were too few cases of HBV reactivation within cohort studies to assess the role of anti-HBs titer on reactivation. The purpose of this study was to systematically review the correlation between anti-HBs titer and the degree of clinically relevant HBV reactivation in patients undergoing anti-TNF therapy.

METHODS AND RESULTS

We systemically reviewed all studies discussing anti-TNF therapy in patients with resolved HBV infection, defined as hepatitis surface antigen (HBsAg) negative and hepatitis B core antibody (anti-HBc) positive. We identified a total of 48 cases of reactivation from 5 cohort studies and 10 case reports or case series; 21 were anti-HBs negative, 7 were only reported as anti-HBs positive, 16 were anti-HBs positive with titer below 100, and 4 were anti-HBs positive with titer above 100. HBsAg sero-reversion was dominantly seen in patients with negative, low and/or declining anti-HBs titers. There was a significant trend toward less clinically relevant form of reactivation with increase in baseline anti-HBs titer (p = 0.022).

CONCLUSION

Anti-HBs titers greater than 100 iU/L protect against clinically relevant HBV reactivation, while patients with low anti-HBs titers or negative anti-HBs had more clinically relevant HBV reactivation and higher rates of HBsAg sero-reversion. This suggests the importance of baseline quantitative anti-HBs prior to starting anti-TNF therapy and consideration vaccination for boosting anti-HBs titers prior to and/or during therapy.

Age-related decline in anti-HBV antibodies in vaccinated kidney transplant recipients

BACKGROUND

Hepatitis B virus (HBV) vaccination is indicated for all end stage kidney disease patients, including all solid organ transplant candidates. Maintenance of adequate immunity is especially important for immunosuppressed solid organ recipients who are at increased risk for donor or community acquired HBV. The impact of age and immunosuppression on long-term maintenance of HBV immunity postvaccination has not been fully investigated.

METHODS

We performed a single-center retrospective study of 96 kidney transplant recipients, transplanted between July 2012 and December 2020, who had Hepatitis B surface antibody (HBsAb) levels measured pretransplantation and 1-year posttransplantation. We compared the change in HBsAb levels stratified by patient's age (<45, 45-60, and >60) and by whether or not the patient received lymphocyte depleting induction therapy.

RESULTS

Our results demonstrate that HBsAb IgG levels vary by age group, decreased significantly at 1-year posttransplant (p < .0001) and were significantly lower in the older cohort (p = .03). Among recipients who received rabbit anti-thymocyte globulin induction (rATG), the log HbsAb levels were significantly lower in the older age group (2.15 in age <45, 1.75 in age 45-60 and 1.47 in age >60, p = .01). Age group (p = .004), recipient HBcAb status (p = .002), and rATG (p = .048) were independently associated with >20% reduction in log HBsAb levels posttransplant.

CONCLUSION

Significant declines in HBsAb levels occur postkidney transplantation, especially in older individuals, thus placing exposed older kidney transplant recipients at greater risk of HBV infection and associated complications.

Use of Hepatitis B Viremic donors in kidney transplant recipients: A single center experience

BACKGROUND

Utilization of Hepatitis B virus (HBV)-infected kidney allografts represents an opportunity to bridge the gap between organ supply and demand. Highly efficacious vaccines and anti-viral therapies allow these allografts to be transplanted with negligible risk to the recipient.

OBJECTIVE

The purpose of this study was to describe the prophylactic strategies and related clinical outcomes of kidney transplant recipients who received a kidney from an HBV viremic donor.

RESULTS

Eight patients received an allograft from an HBV viremic deceased kidney donor between January 1, 2017 and December 4, 2020. All recipients were immune to hepatitis B with a surface antibody titer greater than or equal to 10 mIU/mL (range: 12 - >1000 mIU/mL). After transplant, 62.5% demonstrated HBV core antibody seroconversion at an average of 47.4 ± 28.5 days post-transplant. Anti-viral prophylaxis was initiated in 87.5% of patients; 62.5% preemptively during the transplant admission (range 1-3 days post-transplant) and 25% following HBcAb seroconversion (range 45-304 days post-transplant). Of the four patients who were started on entecavir preemptively, two subsequently core converted. These two patients had an HBV surface antibody less than 100 mIU/mL at the time of transplant. None of the recipients converted to HBV surface antigen positivity. The average estimated glomerular filtration rate was 41 ± 19 mL/min/1.73m² , and there were no significant elevations in liver enzymes through one year post-transplant.

CONCLUSION

The use of HBV viremic kidney allografts may represent an additional source of transplant organs; however, more studies are needed to better elucidate the optimal protective strategies for these recipients. This article is protected by copyright. All rights reserved.

Kidney transplant from donors with hepatitis B: A challenging treatment option

Utilizing kidneys from donors with hepatitis B is one way to alleviate the current organ shortage situation. However, the risk of hepatitis B virus (HBV) transmission remains a challenge that undermines the chance of organs being used. This is particularly true with hepatitis B surface antigen (HBsAg) positive donors despite the comparable long-term outcomes when compared with standard donors. To reduce the risk of HBV transmission, a comprehensive approach is needed. This includes assessment of donor risk, optimal allocation to the proper recipient, appropriate immunosuppressive regimen, optimizing the prophylactic therapy, and post-transplant monitoring. This review provides an overview of current evidence of kidney transplants from donors with HBsAg positivity and outlines the challenge of this treatment. The topics include donor risk assessment by adopting the nucleic acid test coupled with HBV DNA as the HBV screening, optimal recipient selection, importance of hepatitis B immunity, role of nucleos(t)ide analogues, and hepatitis B immunoglobulin. A summary of reported long-term outcomes after kidney transplantation and proposed criteria to utilize kidneys from this group of donors was also defined and discussed.