Impact and Efficacy of Everolimus Rescue Immunosuppression in the Treatment of Chronic Allograft Dysfunction in Renal Transplant Recipients

Despite the remarkable improvement in short-term patient and graft survival among the recipients of kidney transplants, the progressive renal dysfunction (chronic allograft dysfunction) accompanied by chronic interstitial fibrosis, tubular atrophy, vascular occlusive changes and glomerulosclerosis remains the chief cause of graft loss. As a result of this damage from immunologic and non-immunologic injury, the long-term survival of kidney transplants has changed little during the past decade. And, among the non-immunologic factors, calcineurin inhibitor nephrotoxicity has been shown to be the most common factor leading to long-term graft damage and progression to graft failure. This is further supported by the previous finding that long-term use of calcineurin inhibitor-based therapy leads to deterioration in kidney function, even in recipients of non-renal organ transplants.

The growing interest in calcineurin inhibitor minimisation protocols to optimize renal transplant outcome offers a new therapeutic options in the management of patients with chronic allograft dysfunction. Recently, mammalian target-of-rapamycin inhibitors (mTOR inhibitors) including everolimus has been shown to achieve an improvement of long-term function through an early modulation of immunosuppressive regimen. In this aspect, percutaneous renal graft biopsy represents an important diagnostic tool to allow visualization of the lesions of chronic allograft dysfunction and therefore the ability to delineate the potential improvement after introduction of everolimus. Histologic and morphometric findings from a protocol-mandated biopsies obtained from renal transplant recipients who are suffering from chronic allograft dysfunction and treated with everolimus are needed to provide a clinical blueprint for the drug's efficacy, if confirmed.