Philadelphia—Kidney injury and graft failure are increasingly being associated with BK nephropathy. Current literature suggests an association between high immunosuppression dose and increased incidence of BK viruria, viremia, and nephropathy. According to Pradeep Vaitla, MD, and colleagues, most transplant centers in the United States use antibody induction with rabbit antihymocyte globulin or alemtuzumab to minimize maintenance immunosuppression.
The researchers recently conducted a retrospective chart review of 441 kidney transplants performed at a single center from November 2007 to December 2011. Dr. Vaitla et al. reported results of the review during a poster session at Kidney Week 2014 in a poster titled BK Nephropathy in Kidney Transplant Recipients Induced with Alemtuzumab.
The protocol for immunosuppression at the Ochsner Clinic included a single dose of alemtuzumab 30 mg, tacrolimus to achieve serum trough level 7-10 ng/mL, mycophenolate mofetil (MMF) 500 mg orally twice daily, and methylprednisolone 500 mg post-operative day 0, 250 mg post-operative day 1, and 125 mg post-operative day 2 with rapid steroid withdrawal.
Of the 441 kidney transplant charts included in the review, 311 recipients received alemtuzumab for induction immunosuppression; the researchers obtained demographic, laboratory and clinical data (including biopsy proven acute rejection) during 1 year of follow-up.
Current follow-up protocol at the clinic calls for polymerase chain reaction (PCR)-based screening for BK virus in urine at 3, 6, 9, 12, 18, and 24 months post-transplant. A BK viral load >10 million copies/mL is an indication for serum BVK PCR every 2 weeks and a possible kidney biopsy.
Among the 311 transplant recipients, the incidence of BK viruria was 29% (n=90/311); the incidence of BK viremia was 9% (n=9/311); and the incidence of BK nephropathy was 0.9% (n=3/311). At the end of 1 year, the incidence rate of biopsy proven rejection rate was 8% and graft survival rate was 99% for the entire cohort. During follow-up, there was no loss of allografts due to BK nephropathy.
“Induction therapy with alemtuzumab in renal transplant recipients, combined with screening protocol for BJK virus PCR is effective and has a low incidence of BK nephropathy compared with other protocols reported in the transplant literature,” the researchers said.
Source: Vaitla P, Patel U, Mascarenhas RC, et al. BK nephropathy in kidney transplant recipients induced with alemtuzumab, a single center experience. Abstract of poster presented at Kidney Week 2014, Philadelphia, Pennsylvania, November 13, 2014.