HBV-Positive Donor Kidneys Safe, Effective in Immunized HBV-Negative Recipients

Hengjun Xiao, MD

Credit: Third Affiliated Hospital of Sun Yat-sen University

New research is providing evidence supporting the safety and efficacy of using hepatitis B surface antigen (HBsAg)-positive donor kidneys in HBsAg-negative recipients, highlighting a lack of significant impact on the recovery of graft function and overall survival.¹

Findings suggest comparable rates of posttransplant delayed graft function, estimated glomerular filtration rate (eGFR), and graft and recipient survival with low rates of HBV transmission, especially with the maintenance of an HBsAb titer above 100 mIU/mL in non-HBV chronic infection candidates.¹

According to the United States Renal Data System 2020 Annual Data Report, nearly 808,000 people in the US are living with end-stage kidney disease (ESKD), 69% of whom are on dialysis.² Kidney transplantation is the preferred treatment for patients with ESKD because it is associated with reduced mortality and improved quality of life compared to dialysis, but the number of patients with ESKD awaiting a kidney transplant exceeds the number of organ donations globally.³ Recent advances in anti-HBV therapy have allowed for the use of HBV-positive donor kidneys to expand the donor pool, but limited evidence exists regarding the impact on transplant outcomes.¹

“There is currently insufficient evidence regarding the safety and efficacy of HBV-positive kidneys,” Hengjun Xiao, MD, associate chief physician of the department of urology at the Third Affiliated Hospital of Sun Yat-sen University in China, and colleagues wrote.¹

To assess the impact of the use of HBV-positive donor kidneys on transplant outcomes, investigators retrospectively reviewed kidney transplantation cases from January 1, 2015, to December 31, 2021, at a single transplant center. All donor sources were from deceased citizen donors. All data were sourced from the China Organ Transplant Response System, medical records, tests, and examinations from donation hospitals and transplant hospitals.¹

All cases of HBV-positive donors to HBV-negative recipients were reviewed by the transplant teams and the recipients before transplantation, and informed consent was obtained after discussing the balance of benefits and risks with the participants.¹

Acknowledging the different transmission risks of various donor and recipient HBV crossmatch statuses, investigators divided all transplant cases into 3 groups: donor HBsAg+/recipient HBsAg– (D+R–) group; donor HBsAg–/recipient HBsAg– (D–R–) group; and donor HBsAg±/recipient HBsAg+ (D±R+) group. The primary outcomes were recipient HBV infection, delayed graft function, peak eGFR within 12 months, recipient survival, and death-censored graft survival.¹

A total of 743 screened kidney transplantation cases were included for analysis, including 649 D–R– cases and 94 D+R– cases. In total, 231 of 649 D–R– cases and 72 of 94 D+R– cases had HBV tests during follow-up, which constituted the HBV-tested set. Investigators pointed out the D+R– population had a greater proportion of male donors, higher donor and recipient age, a lower proportion of positive panel reactive antibody and recipient hepatitis B surface antibody (HBsAb) prevalence rate, and a higher proportion of donors with a history of diabetes.¹

During a median follow-up of 34 (Interquartile range [IQR], 16–52) months, 9 new HBV infection episodes were observed, 6 of which occurred in patients in the D+R– group. Investigators noted the D+R– group had a significantly increased risk of HBV infection compared to the D–R– group (Relative risk, 6.4; P = .007).¹

In the D+R− group, 4 HBV transmissions occurred in HBV-naïve recipients, resulting in a transmission rate of 26.7%. In recipients with HBsAb titers of 10–100 mIU/mL, the transmission rate was 10.5%. Of note, no transmission occurred in recipients with HBsAb titers of 100–1,000 mIU/mL and over 1,000 mIU/mL. Further analysis revealed the risk of HBV transmission decreased significantly with increasing HBsAb titer (P for trend = .003).¹

Investigators pointed out the D+R– group did not exhibit an increased risk of delayed graft function compared to the D–R– group (Odds ratio, 0.70; P = .51) and noted both groups had similar peak eGFR within 12 months (β = 1.01; P = .71). Additionally, the D+R– group had no significant effect on patient survival (hazard ratio [HR], 0.36; P = .10) or death-censored graft survival (HR, 0.79; P = .59) after adjustment in the shared-frailty Cox model.¹

Investigators outlined several limitations to these findings, including the lack of consideration for donors’ HBV DNA viral load level in serum as an impact factor for analysis; the absence of a regular schedule for HBV monitoring during the follow-up period; the lack of differentiation between HBV transmission and HBV reactivation in HBcAb-positive recipients; and the fact that D+R− recipients were not subdivided into susceptible, immune, and resolved infection groups.¹

“This study demonstrates that the use of HBsAg-positive donor kidneys is relatively safe for HBV-immunized recipients during a short follow-up period,” investigators concluded.¹ “The graft function recovery of HBV-infected donor kidneys is not compromised, as evidenced by comparable rates of posttransplant DGF, eGFR levels, and graft and recipient survival.”

References

1. ^{Luo Y, Zhang R, Hu X, et al. The impact of donor hepatitis B virus infection on transplant outcomes in deceased donor kidney transplantation recipients. Kidney Research and Clinical Practice. doi:https://doi.org/10.23876/j.krcp.23.233}
2. ^{National Institute of Diabetes and Digestive and Kidney Diseases. Kidney Disease Statistics for the United States. Health Statistics. May 2023. Accessed July 31, 2024. https://www.niddk.nih.gov/health-information/health-statistics/kidney-disease}
3. ^{Srisuwarn P, Sumethkul V. Kidney transplant from donors with hepatitis B: A challenging treatment option. World J Hepatol. doi:10.4254/wjh.v13.i8.853}