A pocket guide to identify patients at risk for chronic kidney disease after liver transplantation

Current aspects of renal dysfunction after liver transplantation

The development of chronic kidney disease (CKD) after liver transplantation (LT) exerts a severe effect on the survival of patients. The widespread adoption of the model for end-stage liver disease score strongly impacted CKD incidence after the procedure, as several patients are transplanted with previously deteriorated renal function. Due to its multifactorial nature, encompassing pre-transplantation conditions, perioperative events, and nephrotoxic immunosuppressor therapies, the accurate identification of patients under risk of renal disease, and the implementation of preventive approaches, are extremely important. Methods for the evaluation of renal function in this setting range from formulas that estimate the glomerular filtration rate, to non-invasive markers, although no option has yet proved efficient in early detection of kidney injury. Considering the nephrotoxicity of calcineurin inhibitors (CNI) as a factor of utmost importance after LT, early nephroprotective strategies are highly recommended. They are based mainly on delaying the application of CNI during the immediate postoperative-period, reducing their dosage, and associating them with other less nephrotoxic drugs, such as mycophenolate mofetil and everolimus. This review provides a critical assessment of the causes of renal dysfunction after LT, the methods of its evaluation, and the interventions aimed at preserving renal function early and belatedly after LT.

Prediction of chronic kidney disease after orthotopic liver transplantation: development and validation of a nomogram model

Background

We aimed to develop and validate a nomogram model for predicting CKD after orthotopic liver transplantation (OLT).

Methods

The retrospective data of 399 patients who underwent transplantation and were followed in our centre were collected. They were randomly assigned to the training set (n = 293) and validation set (n = 106). Multivariable Cox regression analysis was performed in the training set to identify predictors of CKD. According to the Cox regression analysis results, a nomogram model was developed and validated. The renal function of recipients was monitored, and the long-term survival prognosis was assessed.

Results

The incidence of CKD at 5 years after OLT was 25.6%. Cox regression analysis identified several predictors of post-OLT CKD, including recipient age at surgery (HR 1.036, 95% CI 1.006-1.068; p = 0.018), female sex (HR 2.867, 95% CI 1.709-4.810; p < 0.001), preoperative hypertension (HR 1.670, 95% CI 0.962-2.898; p = 0.068), preoperative eGFR (HR 0.996, 95% CI 0.991-1.001; p = 0.143), uric acid at 3 months (HR 1.002, 95% CI 1.001-1.004; p = 0.028), haemoglobin at 3 months (HR 0.970, 95% CI 0.956-0.983; p < 0.001), and average concentration of cyclosporine A at 3 months (HR 1.002, 95% CI 1.001-1.003; p < 0.001). According to these parameters, a nomogram model for predicting CKD after OLT was constructed and validated. The C-indices were 0.75 and 0.80 in the training and validation sets. The calibration curve of the nomogram showed that the CKD probabilities predicted by the nomogram agreed with the observed probabilities at 1, 3, and 5 years after OLT (p > 0.05). Renal function declined slowly year by year, and there were significant differences between patients divided by these predictors. Kaplan-Meier survival analysis showed that the survival prognosis of recipients decreased significantly with the progression of renal function.

Conclusions

With excellent predictive abilities, the nomogram may be a simple and reliable tool to identify patients at high risk for CKD and poor long-term prognosis after OLT.

Area Under Trough Concentrations of Tacrolimus as a Predictor of Progressive Renal Impairment After Liver Transplantation

BACKGROUND

Tacrolimus minimization is usually restricted to patients with pretransplant renal impairment, and this strategy could result into worse renal outcomes after liver transplantation (LT).

METHODS

A consecutive cohort of 455 LT patients receiving tacrolimus-based immunosuppression was studied (2008-2013). Cumulative exposure to tacrolimus was calculated as the area under curve of trough concentrations (AUCtc). Patients were stratified as tacrolimus minimization, conventional, or high exposure, according to the thresholds based in the COMMIT consensus. Estimated glomerular filtration rates (eGFR) were assessed by the Modification of Diet in Renal Disease formula (MDRD-4) up to 5 years after LT.

RESULTS

Seventy patients (15.4%) had pretransplant eGFR < 60 mL/min, which was associated with increased mortality rates, particularly within the first 5 years post-LT (31.4% versus 17.5%; Breslow P = 0.010). After LT, there was an abrupt eGFR decline within the first 3 months (median 18.6 mL/min; P < 0.001), further decreasing up to 12 months (additional 3 mL/min), without any improvement thereafter. According to AUCtc, 33.7% of patients received tacrolimus minimization, 44.8% conventional exposure, and 21.5% high exposure. Conventional/high exposure to tacrolimus resulted in a more pronounced eGFR decline within the first 3 months when compared with minimization (23.3 mL/min versus 9.5 mL/min; P < 0.001). This gap was even higher in patients with initially preserved renal function. Tacrolimus AUCtc was an independent predictor of eGFR decline within the first 3 months after controlling for potential confounders.

CONCLUSIONS

AUCtc is a surrogate of cumulative exposure to tacrolimus and may be helpful for routine dose adjustments. Tacrolimus minimization should be universally attempted after LT to preserve renal function.

Temporal validation of the CT-PIRP prognostic model for mortality and renal replacement therapy initiation in chronic kidney disease patients

Background

A classification tree model (CT-PIRP) was developed in 2013 to predict the annual renal function decline of patients with chronic kidney disease (CKD) participating in the PIRP (Progetto Insufficienza Renale Progressiva) project, which involves thirteen Nephrology Hospital Units in Emilia-Romagna (Italy). This model identified seven subgroups with specific combinations of baseline characteristics that were associated with a differential estimated glomerular filtration rate (eGFR) annual decline, but the model’s ability to predict mortality and renal replacement therapy (RRT) has not been established yet.

Methods

Survival analysis was used to determine whether CT-PIRP subgroups identified in the derivation cohort (n = 2265) had different mortality and RRT risks. Temporal validation was performed in a matched cohort (n = 2051) of subsequently enrolled PIRP patients, in which discrimination and calibration were assessed using Kaplan-Meier survival curves, Cox regression and Fine & Gray competing risk modeling.

Results

In both cohorts mortality risk was higher for subgroups 3 (proteinuric, low eGFR, high serum phosphate) and lower for subgroups 1 (proteinuric, high eGFR), 4 (non-proteinuric, younger, non-diabetic) and 5 (non-proteinuric, younger, diabetic). Risk of RRT was higher for subgroups 3 and 2 (proteinuric, low eGFR, low serum phosphate), while subgroups 1, 6 (non-proteinuric, old females) and 7 (non-proteinuric, old males) showed lower risk. Calibration was excellent for mortality in all subgroups while for RRT it was overall good except in subgroups 4 and 5.

Conclusions

The CT-PIRP model is a temporally validated prediction tool for mortality and RRT, based on variables routinely collected, that could assist decision-making regarding the treatment of incident CKD patients. External validation in other CKD populations is needed to determine its generalizability.

VI consensus document by the Spanish Liver Transplantation Society

The goal of the Spanish Liver Transplantation Society (La Sociedad Española de Trasplante Hepático) is to promote and create consensus documents about current topics in liver transplantation with a multidisciplinary approach. To this end, on October 20, 2016, the 6th Consensus Document Meeting was held, with the participation of experts from the 24 authorized Spanish liver transplantation programs. This Edition discusses the following subjects, whose summary is offered below: 1) limits of simultaneous liver-kidney transplantation; 2) limits of elective liver re-transplantation; and 3) liver transplantation after resection and hepatocellular carcinoma with factors for a poor prognosis. The consensus conclusions for each of these topics is provided below.

VI consensus document by the Spanish Liver Transplantation Society

The goal of the Spanish Liver Transplantation Society (La Sociedad Española de Trasplante Hepático) is to promote and create consensus documents about current topics in liver transplantation with a multidisciplinary approach. To this end, on October 20, 2016, the 6th Consensus Document Meeting was held, with the participation of experts from the 24 authorized Spanish liver transplantation programs. This Edition discusses the following subjects, whose summary is offered below: 1) limits of simultaneous liver-kidney transplantation; 2) limits of elective liver re-transplantation; and 3) liver transplantation after resection and hepatocellular carcinoma with factors for a poor prognosis. The consensus conclusions for each of these topics is provided below.

Combination of TACE and Sorafenib Improves Outcomes in BCLC Stages B/C of Hepatocellular Carcinoma: A Single Centre Experience

BACKGROUND AND AIM

Transarterial chemoembolization (TACE) or sorafenib is recommended for hepatocellular carcinoma BCLC stages B and C respectively. We studied the role of combination of TACE and sorafenib in BCLC stages B/C.

MATERIAL AND METHODS

We undertook an observational study on a cohort of cirrhotics with HCC from August 2010 through October 2014. Patients in BCLC stages B/C who had received TACE and/or sorafenib were included. mRECIST criteria were used to assess tumor response. The primary end point was overall survival.

RESULTS

Out of 124 patients, 47.6% were in BCLC-B and 52.4% in BCLCC. Baseline characteristics were comparable. The predominant etiology was cryptogenic (37.2% and 38.5%, p = NS). 49.1% in BCLC-B and 56.9% in BCLC-C had received TACE+sorafenib. In BCLC-B, the overall survival improved from 9 months (95% CI 6.3-11.7) using TACE only to 16 months (95% CI 12.9-19.1) using TACE+sorafenib (p &lt; 0.05). In BCLC-C, addition of TACE to sorafenib improved the overall survival from 4 months (95%CI 3-5) to 9 months (95%CI 6.8-11.2) (p &lt; 0.0001). As per mRECIST criteria, patients on TACE+sorafenib had reduced progressive disease (37.8% vs. 83.3%), improved partial response (43.2% vs. 3.3%) and one had complete response compared to those on sorafenib alone (p &lt; 0.0001) in BCLC-C but not in BCLC-B group. Hand foot syndrome was noted in 27.7% patients on sorafenib and post TACE syndrome in 80.2% patients, but both were reversible. No major adverse events were noted.

CONCLUSION

TACE+sorafenib was more effective than TACE or sorafenib alone in HCC BCLC stages B or C with a significant survival benefit and improved tumour regression especially in BCLC-C patients.

Results of Simultaneous Liver and Kidney Transplantation: A Single-Center Review

BACKGROUND

The decision for a simultaneous liver and kidney transplantation (SLKT) is fraught with controversy. The aim of this study was to compare SLKT with liver transplantation alone (LTA) in patients with pretransplantation renal failure.

STUDY DESIGN

A retrospective review comparing patients undergoing SLKT and LTA (with renal failure) between January 2000 and December 2014 was performed.

RESULTS

Of 1,129 liver transplantations, 132 had renal failure pretransplantation; 52 had SLKT and 80 recipients had LTA. Model for End-Stage Liver Disease score and BMI were lower in the SLKT group (p = 0.001). Simultaneous liver and kidney transplantation patients had better overall survival rates at 1 and 5 years compared with LTA (92.3% and 81.6% vs 73.3% and 64.3% respectively; p < 0.01). Graft survival was also superior in patients undergoing SLKT vs LTA. Six of 52 (11.5%) SLKT patients had final positive cross match, but only 1 of 52 (1.9%) kidney grafts was lost to rejection. In the SLKT group, 9 of 52 (17.3%) patients required dialysis post transplantation, but only 2 remained on dialysis beyond 30 days. All patients in the LTA group were on dialysis pretransplantation and significantly more patients (52 of 80 [65%]) required dialysis post LTA (p ≤ 0.0001); 31 of 80 (38.8%) were dialysis dependent for more than 30 days or died on dialysis within 30 days. Two LTA recipients were subsequently listed for kidney transplant.

CONCLUSIONS

Patients with end-stage liver disease on dialysis who undergo liver transplantation have significantly better survival when SLKT is performed. In selected patients, SLKT is an appropriate use of a scarce resource, but better prognostic indicators for selection of patients are still needed.