De-novo Belatacept Therapy Is Associated With More BK Viremia And Less BK Clearance In Kidney Transplantation Patients

Author(s):
Gregory Petrossian; Jorge Ortiz; Kathryn Addonizio; Alexander Hsiao; Lisa Teixeira; Naoru Koizumi; Rosy James; Sunil Patel; David Conti; Robert Plews

Background:

Recently there has been increased utilization of belatacept (bela) for long-term maintenance immunosuppression following kidney transplantation. However, data regarding the risk of post-transplant BK viremia in de-novo bela patients is limited.

Hypothesis:

De-novo belatacept maintenence immunosuppression will be associated with increased rates and severity of BK viremia in patients after kidney transplantation.

Methods:

Patients who underwent kidney transplantation at one academic medical center between 2015 to 2021 were divided into two groups based on maintenance immunosuppression regimens: standard dose mycophenolate, rapamune, and tacrolimus vs. low-dose mycophenolate, low-dose tacrolimus, and bela (5.0 mg/kg monthly). Serum BK polyoma PCR was obtained monthly and continued for two years or until establishing viral clearance following transplantation. BK viremia was defined as a PCR level >3,000 copies/mL. The severity of BK viremia was stratified based on maximum quantified levels of >5,000 and >10,000 copies/mL. Time intervals from transplantation to BK viremia and the incidence of acute rejection within the first 12 months following transplant was also assessed.

Results:

246 no bela vs. 119 de-novo bela patients were identified. There was a significant difference in the incidence of BK viremia between bela and no bela treatment groups (28.6% vs. 16.7%, respectively, p=.01). Bela treatment was also associated with significantly higher maximum quantified levels of >5,000 (bela 25.2% vs. no bela 14.6%, p=.02) and >10,000 (bela 21.8% vs. no bela 13%, p=.04). The time interval from transplantation to viremia was similar between groups (mean days: bela 167 vs. no bela 213, p=.30). Patients receiving bela were less likely to achieve clearance of BK viremia when compared with no bela (21.6% vs. 72.6%, respectively, p<.001). Acute rejection within 12 months of transplantation was similar between bela (2.6%) and no bela (2.3%).

Conclusions:

Our data shows that de-novo belatacept treatment is associated with a significantly greater incidence of BK viremia despite similar rates of treatment for acute rejection. Additionally, bela was associated with higher maximum BK titers, and a lower likelihood of complete viremia clearance. Therefore, belatacept-based maintenance immunosuppression may necessitate more vigilant post-operative BK surveillance and immunosuppression tapering at the onset of BK viremia diagnosis.