Incidence and risk factors of renal dysfunction after liver transplantation in Korea

[Kidney failure after liver transplantation]

One third of cirrhotic patients present impaired kidney function. It has multifactorial causes and has a harmful effect on patients' morbi-mortality before and after liver transplant. Kidney function does not improve in all patients after liver transplantation and liver-transplant recipients are at high risk of developing chronic kidney disease. Causes for renal dysfunction can be divided in three groups: preoperative, peroperative and postoperative factors. To date, there is no consensus for the modality of evaluation the risk for chronic kidney disease after liver transplantation, and for its prevention. In the present review, we describe the outcome of kidney function after liver transplantation, and the prognostic factors of chronic kidney disease to determine a risk stratification for each patient. Furthermore, we discuss therapeutic options to prevent kidney dysfunction in this setting, and highlight the indications of combined liver-kidney transplantation.

Kidney Failure after Liver Transplantation

One-third of patients with cirrhosis present kidney failure (AKI and CKD). It has multifactorial causes and a harmful effect on morbidity and mortality before and after liver transplantation. Kidney function does not improve in all patients after liver transplantation, and liver transplant recipients are at a high risk of developing chronic kidney disease. The causes of renal dysfunction can be divided into three groups: pre-operative, perioperative and post-operative factors. To date, there is no consensus on the modality to evaluate the risk of chronic kidney disease after liver transplantation, or for its prevention. In this narrative review, we describe the outcome of kidney function after liver transplantation, and the prognostic factors of chronic kidney disease in order to establish a risk categorization for each patient. Furthermore, we discuss therapeutic options to prevent kidney dysfunction in this context, and highlight the indications of combined liver–kidney transplantation.

Outcomes after liver transplantation in Korea: Incidence and risk factors from Korean transplantation registry

BACKGROUND/AIMS

To analyze the incidence and risk factors of outcomes after liver transplantation (LT) in the Korean population.

METHODS

This study analyzed data from the liver cohort of Korean Organ Transplantation Registry (KOTRY) who had LT between May 2014 and December 2017. Study measures included the incidence of post-LT outcomes in recipients of living donor LT (LDLT) and deceased donor LT (DDLT). Cox multivariate proportional hazards model was used to determine the potential risk factors predicting the outcomes.

RESULTS

A total of 2,563 adult recipients with LT (LDLT, n=1,956; DDLT, n=607) were included, with mean±standard deviation age of 53.9±8.9 years, and 72.2% were male. The post-LT outcomes observed in each LDLT and DDLT recipients were death (4.0% and 14.7%), graft loss (5.0% and 16.1%), rejection (7.0% and 12.0%), renal failure (2.7% and 13.8%), new onset of diabetes (12.5% and 15.4%), and hepatocellular carcinoma (HCC) recurrence (both 6.7%). In both LDLT and DDLT recipients, the most common post-LT complications were renal dysfunction (33.6% and 51.4%), infection (26.7% and 48.4%), and surgical complication (22.5% and 23.9%). Incidence of these outcomes were generally higher among recipients of DDLT than LDLT. Multivariate analysis indicated recipient age and DDLT as significant risk factors associated with death and graft loss. DDLT and ABO incompatible transplant were prognostic factors for rejection, and HCC beyond Milan criteria at pre-transplant was a strong predictor of HCC recurrence.

CONCLUSION

This study is a good indicator of the post-LT prognosis in the Korean population and suggests a significant burden of post-LT complications.

Chronic Kidney Disease after Liver Transplantation: Recent Evidence

Chronic kidney disease is a common complication after liver transplantation with an incidence ranging between 20% and 80%. Studies of renal function after liver transplantation have yielded conflicting results: the wide range in incidence rates of chronic kidney disease (CKD) following liver transplantation is related to the methods for measuring kidney function, and various criteria for defining renal dysfunction, among others. An important cause of CKD among liver transplant recipients is calcineurin inhibitor-based immunosuppression. Additional predictors of CKD post-liver transplantation include pre-transplant kidney function, peri-operative acute kidney failure, age, and hepatitis C. A recent meta-analysis of observational studies revealed that, in the subgroup of studies provided with glomerular filtration rate at baseline, the summary estimate of relative risk and 95% confidence intervals (CI) for developing chronic renal failure among liver transplant recipients with diminished renal function at transplant was 2.12 (95% CI, 1.01–4.46, p=0.047). Acute renal insufficiency is common immediately after liver transplantation, whereas the course of CKD after liver transplantation appears progressive over time. Only preliminary information exists on kidney pathological findings in recipients of liver transplants with CKD. Introduction of the Model for End-stage Liver Disease for the allocation of liver grafts has not increased the occurrence of renal dysfunction following liver transplantation. Chronic kidney disease following liver transplantation increases cardiovascular burden dramatically. The use of mycophenolic acid- or sirolimus-based immunosuppression in calcineurin-inhibitors sparing protocols is an area of intense research.

Clinical Risk Scoring Models for Prediction of Acute Kidney Injury after Living Donor Liver Transplantation: A Retrospective Observational Study

Acute kidney injury (AKI) is a frequent complication of liver transplantation and is associated with increased mortality. We identified the incidence and modifiable risk factors for AKI after living-donor liver transplantation (LDLT) and constructed risk scoring models for AKI prediction. We retrospectively reviewed 538 cases of LDLT. Multivariate logistic regression analysis was used to evaluate risk factors for the prediction of AKI as defined by the RIFLE criteria (RIFLE = risk, injury, failure, loss, end stage). Three risk scoring models were developed in the retrospective cohort by including all variables that were significant in univariate analysis, or variables that were significant in multivariate analysis by backward or forward stepwise variable selection. The risk models were validated by way of cross-validation. The incidence of AKI was 27.3% (147/538) and 6.3% (34/538) required postoperative renal replacement therapy. Independent risk factors for AKI by multivariate analysis of forward stepwise variable selection included: body-mass index >27.5 kg/m² [odds ratio (OR) 2.46, 95% confidence interval (CI) 1.32–4.55], serum albumin <3.5 mg/dl (OR 1.76, 95%CI 1.05–2.94), MELD (model for end-stage liver disease) score >20 (OR 2.01, 95%CI 1.17–3.44), operation time >600 min (OR 1.81, 95%CI 1.07–3.06), warm ischemic time >40 min (OR 2.61, 95%CI 1.55–4.38), postreperfusion syndrome (OR 2.96, 95%CI 1.55–4.38), mean blood glucose during the day of surgery >150 mg/dl (OR 1.66, 95%CI 1.01–2.70), cryoprecipitate > 6 units (OR 4.96, 95%CI 2.84–8.64), blood loss/body weight >60 ml/kg (OR 4.05, 95%CI 2.28–7.21), and calcineurin inhibitor use without combined mycophenolate mofetil (OR 1.87, 95%CI 1.14–3.06). Our risk models performed better than did a previously reported score by Utsumi et al. in our study cohort. Doses of calcineurin inhibitor should be reduced by combined use of mycophenolate mofetil to decrease postoperative AKI. Prospective randomized trials are required to address whether artificial modification of hypoalbuminemia, hyperglycemia and postreperfusion syndrome would decrease postoperative AKI in LDLT.

Clinical usefulness of kidney biopsy in liver transplant recipients with renal impairment

Background

Chronic kidney disease is a common complication after liver transplantation. In this study, we analyzed the results of kidney biopsy in liver transplantation recipients with renal impairment.

Methods

Between 1999 and 2012, 544 liver transplants were performed at our hospital. We retrospectively analyzed the clinical and histological data of 10 liver transplantation recipients referred for kidney biopsy.

Results

The biopsies were performed at a median of 24.5 months (range, 3–73 months) after liver transplantation. The serum creatinine level was 1.81±0.5 mg/dL at the time of kidney biopsy. There were no immediate complications. The most common diagnosis was glomerulonephritis (GN), such as immunoglobulin A nephropathy (n=4), mesangial proliferative GN (n=1), focal proliferative GN (n=1), and membranous GN (n=1). Typical calcineurin inhibitor (CNI)-induced nephrotoxicity was detected in three cases (30%). Chronic tissue changes such as glomerulosclerosis, interstitial fibrosis, and tubular atrophy were present in 90%, 80%, and 80% of cases, respectively, and mesangial proliferation was detected in 40% of cases. We began treatment for renal impairment based on the result of kidney biopsy; for example, angiotensin-receptor blockers or steroids were prescribed for GN, and the CNI dose was reduced for CNI nephrotoxicity. As a result, eight of 10 patients showed improvement in glomerular filtration rate, but two progressed to end-stage renal disease.

Conclusion

Kidney biopsy is a safe and effective method for determining the cause of renal impairment after liver transplantation. Management of patients based on the result of kidney biopsy may improve renal outcomes.

Risk factors for consequent kidney impairment and differential impact of liver transplantation on renal function

BACKGROUND

Chronic kidney disease (CKD) develops frequently after liver transplantation (LTx), and it is important to identify and correct risk factors that negatively affect kidney function. Risk factors have not been well evaluated in Asian countries where hepatitis B virus (HBV) infection is a dominant cause.

METHODS

Four hundred thirty-one Korean recipients who underwent LTx between 1997 and 2008 were analysed. CKD was defined as a sustained decrease in estimated glomerular filtration rate (eGFR) of <60 (mL/min/1.73 m(2)) for at least three consecutive months using an abbreviated Modification in Renal Disease (MDRD) formula.

RESULTS

Eighty percent of the patients had HBV-related underlying diseases. The recipients whose pretransplant eGFR had been low (<30 mL/min/1.73 m(2)) improved their renal function after LTx, but significant functional decline occurred in recipients whose pretransplant eGFR was high (>or=60 mL/min/1.73 m(2)). A multivariate Cox regression analysis revealed that the overall risk of CKD development (eGFR < 60 mL/min/1.73 m(2)) was associated with old age of recipients, cyclosporine, posttransplant acute renal failure (ARF), cause [calcineurin inhibitor (CNI) nephrotoxicity] and severity of posttransplant ARF, low pretransplant eGFR, pretransplant hepatorenal syndrome, pretransplant proteinuria, high Child-Pugh score and high Model for End-Stage Renal Disease (MELD) score. Especially in recipients whose pre-operative eGFR was high (>or=60 mL/min/1.73 m(2)), rapid progression of kidney disease was associated with high tacrolimus level, non-HBV disease, posttransplant ARF, cause (CNI nephrotoxicity) and severity of posttransplant ARF and Child-Pugh score. CNI toxicity and focal segmental sclerosis, but not immune-complex disease, were revealed as significant contributors to CKD after LTx in HBV recipients.

CONCLUSION

Judicious use of CNIs should be applied to liver recipients to prevent kidney dysfunction.

Early Postoperative Renal Dysfunction in the Adult Living Donor Liver Transplantation

Living donor liver transplantation (LDLT) is a widely accepted treatment for end-stage liver diseases. Renal dysfunction, a frequent complication after liver transplantation, has an unfavorable effect on the prognosis. Despite special characteristics of LDLT, such as small-for-size graft syndrome (SFS), the relations between graft size and postoperative renal dysfunction have not been evaluated. So we described the relevance of previously known risk factors with SFS (graft-recipient body weight ratio [GRWR] < 0.8%) and early postoperative renal dysfunction in LDLT. The study population consisted of adults who received LDLT from May 1996 to November 2005. The 284 patients who were followed to 3 months after LDLT were classified as group I (n = 201, creatinine < 1.5 mg/dL) versus group II (n = 83, creatinine > or = 1.5 mg/dL). Univariate analysis showed renal dysfunction in the early postoperative period was related to preoperative total bilirubin, blood urea nitrogen, creatinine, prothrombin time level, model for end-stage liver disease (MELD) score, GRWR, presence of preoperative renal dysfunction, transfusion of packed red blood cell, fresh frozen plasma, cryoprecipitate, reoperation, and the need for renal replacement therapy (RRT). Upon multivariate analysis, MELD score, GRWR, preoperative renal dysfunction, and need for RRT were related to early postoperative renal dysfunction. In conclusion, there was a significant relationship between SFS (GRWR < 0.8) and early postoperative renal dysfunction.

Chronic kidney disease post-liver transplantation

BACKGROUND

Renal disease is a recognized complication of orthotopic liver transplantation (OLT). We aimed to determine the incidence of all stages of chronic kidney disease (CKD), as defined in the Kidney Disease Outcomes Quality Initiative Guidelines. We also wanted to determine the risk factors for development of CKD and its impact on patient survival.

METHODS

All patients who underwent cadaveric OLT, from January 1993 until July 2004, were analysed. The glomerular filtration rate (GFR) was determined using the equation developed by the Modification of Diet in Renal Disease Study. Thirty potential risk factors were examined by univariate and multivariate ordinal logistic regression analysis. Kaplan-Meier survival analysis, the log-rank test and Cox regression analysis were performed to evaluate the survival data.

RESULTS

A total of 230 patients were included (107 males and 123 females) with a mean age of 47.7 years (4.5-70.35). Mean follow-up was 5.57 years (0.53-16.5). The following was the 10 year cumulative incidence for each stage of CKD: 0/1, 9.61%; 2, 53.71%; 3, 56.77%; 4, 6.11%; 5, 2.62%. Female gender, age, pre-OLT proteinuria, lower GFR from 1 year and higher creatinine from 6 months were associated with progression of CKD. The use of tacrolimus had a favourable impact. A GFR <30 ml/min, the need for re-transplantation and fulminant hepatic failure were all associated with reduced patient survival.

CONCLUSIONS

Moderate CKD was very prevalent. We identified the risk factors for progression of CKD and also that severe CKD was associated with reduced patient survival.