CHAPTER 21: Chronic Kidney Disease in Nonrenal Solid Organ Transplantation

INTRODUCTION

Chronic kidney disease (CKD) is a major contributor to morbidity and mortality after solid organ transplantation (SOT).¹ CKD not only occurs after kidney transplantation, but its incidence is higher in virtually all SOT recipients. In this chapter we will review the incidence of CKD in nonrenal SOT, the pathophysiology of CKD in SOT, and the means of reducing the incidence of CKD in nonrenal SOT.

EPIDEMIOLOGY

In a landmark paper, Ojo and colleagues found CKD to be common in a variety of SOT recipients. With a median follow-up of 23 years, CKD stage 4 or greater developed in 16.5% of all SOT patients, and 4.7% required maintenance dialysis. Five-year risk of CKD varied according to type of SOT and ranged from 6.9% to 21.3%. Predictors of CKD included increasing age, female sex, pretransplant hepatitis C, hypertension (HTN), diabetes, and postoperative acute kidney injury (AKI). The following points summarize the risk of CKD per type of nonrenal SOT:

• Heart: 10.9% developed CKD stage 4 in 5 years

• Heart/lung: 6.9% developed CKD stage 4 in 5 years

• Intestine: 21.3% developed CKD stage 4 in 5 years

• Liver transplantation: 18.1% developed CKD stage 4 in 5 years

• Lung: 15.8% developed CKD stage 4 in 5 years

Other studies focusing on specific types of organ transplantation have found similar risks.

Heart and Lung Transplantation

• In a study of lung and heart/lung transplant recipients with median follow-up of 79 months, 55% had doubled their serum creatinine and 7.3% progressed to end-stage kidney disease (ESKD). Most of the loss in kidney function occurred within the first year.²

• In a single-center study of heart transplant recipients, the cumulative incidence of CKD stage 4 was 4.2%, 10.4%, and 12.5% at 5, 10, and 15 years of follow-up. Pretransplant estimated glomerular filtration rate (eGFR) was an important predictor of posttransplant decline of renal function.³

Intestine Transplantation

• The highest incidence of CKD seems to occur after intestine transplantation. In a recent study of the Scientific Registry of Transplant Recipients (SRTR), Huard et al. found the cumulative incidence of CKD stage 4 or greater to be 3.2%, 35.2%, and 54.1% at 1, 5, and 10 years after intestine transplant.⁴

Liver Transplantation

• The incidence of ESKD has been found to be as high as 9.5% at 13 years post–liver transplantation. Patients with hepatorenal syndrome pretransplant may have a higher risk of ESKD post–liver transplantation.⁵

Pancreas Transplantation

CKD has also been seen after pancreas transplantation. However, early decline seems to stabilize after 10 years, possibly from improvement of baseline diabetic lesions in the kidney.⁶

In all reports posttransplant CKD has been associated with worse mortality.