Clinical course of kidney transplant patients with acute rejection and BK virus replication following Campath therapy

Background: Kidney transplant recipients with active BK virus (BKV) replication are generally treated with reduction in immunosuppression to allow a successful immune response against the virus. Methods: We inadvertently administered Campath to two patients with BKV viruria, and one patient with BKV nephropathy, since allograft biopsies showed severe tubulitis or intimal arteritis, and results of PCR and in situ hybridization were not available at the time of therapeutic intervention. Results: Increased viral replication was observed, but not uniformly in all cases, and follow-up biopsies showed nephropathy in one additional case. Extra-renal dissemination did not occur. With subsequent reduction of immunosuppression or antiviral therapy, it was still possible to obtain clearance of viremia in all cases. Serum creatinine fell transiently after Campath in one patient; however, at one yr post-treatment all had increased levels over baseline. One graft was lost to persistent acute rejection that led to interstitial fibrosis and tubular atrophy. Conclusions: These cases suggest that Campath treatment does not (i) irreversibly deplete cells believed to be important in mounting an immune response against BKV, or (ii) preclude subsequent eradication of viral DNA from the blood.