Long-term renal function deteriorates at a similar rate among liver transplant patients with preserved renal function at 1 year and in the general population: is chronic calcineurin inhibitor nephrotoxicity overrated?

Abstract

Background: Chronic calcineurin inhibitor (CNI) nephrotoxicity is associated with histologic kidney lesions, but the contribution of maintenance-dose CNI use to the decline over time in glomerular filtration rate (GFR) post liver transplantation (OLT) remains unclear.

Methods: We studied annual changes in estimated GFR >1 year posttransplant among 105 CNI-treated adult OLT patients with a GFR of 60-100 mL/min at 1 year during a mean follow-up of 7 years (20 years in 20 patients).

Results: The annual GFR decline >1 year posttransplant was 0.2 mL/min per year (SD 3.8). This decline rate was unaffected by the decade of OLT, follow-up period, or GFR at 1 year, and showed no correlation with CNI blood levels. Of the 13 (12%) patients with a GFR deterioration >3 mL/min per year, 77% presented with hypertension, diabetes, and/or dyslipidemia. The decline in GFR >1 year post-OLT did not exceed the decline of 0.5-0.8 mL/min per year reported in the general population. Declines faster than 3 mL/min per year, which occurred no more frequently among patients than in the general population, seemed attributable to coexistent vascular risk factors.

Conclusions: Among OLT patients with preserved renal function at 1 year posttransplant, our findings challenge the clinical impact of chronic progressive CNI nephrotoxicity and highlight the importance of a tight control of blood pressures, glucose and lipid levels, and other modifiable risk factors in order to preserve long-term renal function.