Nephrologists should be aware of HBV flare in kidney transplant recipients
Kidney transplantation in hepatitis B virus (HBV)-infected donors and/or recipients has become possible with the advent of antiviral therapies, but nephrologists should be aware of the potential risks of HBV flare and ensure that timely preventive measures are instituted.
“HBV infection in kidney recipients can manifest as acute hepatitis, chronic hepatitis, fibrosing cholestatic hepatitis, cirrhosis and hepatocellular carcinoma. HBV core antibody [anti-HBc] positivity and HBV surface antigen [HBsAg] positivity are predictors of deceased donor kidney discard in the US,” said Professor Tak-Mao Chan of the Department of Medicine, The University of Hong Kong. [Transplantation 2017;101:1690-1697] “However, as an HBV endemic area and due to the low organ donation rate, discarding HBsAg-positive kidney in Hong Kong may not be feasible.”
“For an HBsAg-positive kidney donor, transplantation appears safe if the recipient is HBsAg-positive or has HBV surface antibody [anti-HBs] levels >10 IU/mL. In both cases, prophylactic antiviral therapy is needed,” he continued. “In general, kidney transplantation should not be performed from an HBsAg-positive donor to an HBsAg-negative and anti-HBs–negative recipient, but may be considered under exceptional circumstances and should always be accompanied by antiviral therapies.”
“Kidney transplantation is possible in donors who had HBV clearance following prior HBV exposure [ie, HBsAg-negative but anti-HBc–positive],” noted Chan. “Antivirals should be given to HBsAg-positive recipients as well as HBsAg-negative and anti-HBs–negative recipients following transplantation. For HBsAg-negative and anti-HBs–positive recipients, antivirals are not required except when anti-HBc–positive recipients are given rituximab or other potent immunosuppressive biologics.”
According to Chan, treatment of HBV infection in kidney transplant recipients has become possible and simple with the advent of antiviral therapies.
“The nucleos[t]ide analogues entecavir and tenofovir are the mainstay of HBV antiviral therapy for kidney transplant recipients,” he said. “Adefovir, telbivudine and lamivudine are associated with higher rates of side effects and drug resistance. Interferon should not be used in this context, as it may induce allograft dysfunction and acute rejection.”
At Chan's centre, antiviral treatment has led to significant survival improvements in kidney transplant recipients vs a historical cohort with no antiviral treatment (20-year survival rate, 83 percent vs 34 percent; p=0.006). [Transplantation 2010;90:325-330]
“In HBV-infected kidney recipients, HBV reactivation and hepatitis flares are frequently reported after immunosuppression,” noted Chan. “Currently, prophylactic treatment is the standard practice in patients at high risk of HBV flare. Entecavir and tenofovir have high barrier to drug resistance and good renal safety profile, and are therefore the most commonly used first-line options for treatment-naïve renal transplant recipients.”
“Tenofovir alafenamide [TAF] is a newer formulation of tenofovir. Compared with the older formulation tenofovir disoproxil fumarate, TAF has similar efficacy but a better renal safety profile,” he added.
“While consultation with hepatologists is essential in the management of kidney transplant recipients, nephrologists must be aware of the potential risks and complications of HBV infection, and ensure that timely preventive measures are instituted,” Chan concluded.