*Purpose: Background: De novo donor specific anti-HLA antibodies (dnDSA) has profound effect on the renal graft long-term function and survival. Studies has shown identifications of dnDSA in transplant recipients and pre-emptive treatment may improve graft function. However, in the process of clearing antibodies with intensive immunosuppressive treatment can have unintended consequence of increasing infection risks.

The Objective of this study is to examine how systemic monitoring dnDSA and aggressive management protocol for positive dnDSA can effect the development of BK viremia at one single center (Erie County Medical Center).

*Methods: This is a retrospective cohort study of patients who received a kidney transplant at ECMC from 1/1/2012 to 12/31/2017. Immunosuppression consisted of thyroglobulin induction (3-4.5 mg/kg) followed by tracrolimus, MMF, and prednisone. Development of dnDSA was assessed at 1, 2, 3, 6, 12 months, and then yearly thereafter; more frequently if DSA was positive (MFI>1500). If dnDSA with MFI >3000 is present, maintenance immunosuppression was maximized, biopsy of transplant kidney was performed, and specific treatments based on biopsy findings were performed. Plasma BK PCR was screening at monthly post-transplant for 6 months, then every 3 months until 12 months post-transplant; if BK PCR is positive, the frequencies of testing is based on clinical indications. We examined and compared the development of BK viremia in patients who developed dsDSA vs. those who did not developed dsDSA.

*Results: About 12% (n=71) kidney transplant recipients developed dnDSA, with HLA class 1 occurring earlier, and HLA class 2 occurring later post-transplant. There were 489 recipients with no dsDSA . The rate of BK viremia in dsDSA recipients was 29.6%, higher than in those without dsDSA (22%, p<0.05). The dnDSA were grouped in 5 groups: transient dnDSA without intervention (N=13), transient dnDSA with intervention (N=19), persistent DSA with MFI <3000 (N=12), persistent DSA with MFI 3000-6000 (N=8), persistent DSA with MFI >6000 (N=22). In each above groups, % of BK viremia ranges between 25-31%. Factors attributed to development of dnDSA included rejection (20%:AMR, ACR, mixed), infection [16%: 9 BK, 1 UTI, 2 CMV], high cPRA/prior transplant (15%), non-adherence (11%), unknown (5%), cancer (4%).

*Conclusions: As expected, in the kidney transplant recipients with De Novo DSA who required more intense immunosuppression treatment have higher rate of BK viremia. Development of dnDSA can be a consequence of lowering immunosuppressive regimen secondary to infection such as development of BK viremia, or as consequence of increasing immunosuppression regimen secondary of rejections. Careful monitoring plasma BK PCR is warranted in transplant recipients who are receiving intensified immunosuppressive therapy.

« Back to 2020 American Transplant Congress