Simultaneous liver-kidney transplantation summit: current state and future directions

Simultaneous Liver-Kidney Transplant: Too Many or Just Enough?

For liver transplant candidates with advanced kidney dysfunction, simultaneous liver-kidney (SLK) transplantation is an important option. As the incidence of severe kidney dysfunction has increased over the past decade, so have the numbers of SLK transplants. This has engendered controversy within the transplant community because SLK transplants draw deceased donor kidneys from the kidney transplant candidate pool. Because kidney recovery after liver transplant alone (LTA) is difficult to predict, indications for SLK are not precisely defined. Candidates with hepatorenal syndrome can have kidney recovery after as much as 12 weeks on dialysis, whereas those with CKD may have early ESRD after LTA because of perioperative events and calcineurin inhibitor exposure. Although large observational studies generally show slightly improved survival in SLK recipients compared with LTA, inferences from these studies are limited by selection biases. Therefore, a true survival benefit of SLK in candidates without ESRD is still unproved. Although selection practices vary, generally LTA candidates have more kidney dysfunction because of hepatorenal syndrome and acute kidney injury, whereas SLK candidates have less severe liver disease and more CKD or ESRD. The debate over appropriate SLK is primarily one of the optimal kidney utilization vs the best interests of individual liver transplant candidates.

Kidney Failure and Liver Allocation: Current Practices and Potential Improvements

In February 2002, the United Network for Organ Sharing implemented a system for prioritizing candidates for liver transplantation that was based on the risk of 90-day mortality as determined by the Model for End-Stage Liver Disease (MELD) score. As the MELD score is driven in part by serum creatinine as a marker of kidney function, the prevalence of kidney dysfunction and failure in patients with end-stage liver disease at the time of listing and at transplantation has steadily risen. In this review, we discuss current practices in liver transplantation in patients with kidney dysfunction focusing briefly on the decision to perform simultaneous liver-kidney transplantation. We then discuss pitfalls to the current practices of liver transplantation in patients with kidney dysfunction. We conclude by discussing potential improvements to current practices including the use of the MELD-Na score, alternatives to creatinine and creatinine-based equation for estimating kidney function, and the use of intraoperative kidney replacement therapy during liver transplantation.

Early post-transplant survival: Interaction of MELD score and hospitalization status

BACKGROUND & AIMS

Urgency-based allocation that relies on the MELD score prioritizes patients at the highest risk of waitlist mortality. However, identifying patients at greatest risk for short-term post-transplant mortality is needed in order to optimize the potential gains in overall survival obtained through improved long-term management of transplant recipients. There are limited data on the predictive ability of MELD score for early post-transplant mortality, and no data assessing the interaction between MELD score and hospitalization status.

METHODS

We analyzed UNOS data from 2002 to 2013 on 50,838 non-status 1 single-organ liver transplant recipients and fit multivariable logistic models to evaluate the association and interaction between MELD score and pre-transplant hospitalization status on short-term post-transplant mortality.

RESULTS

There was a significant interaction (p<0.01) between laboratory MELD score and hospitalization status on three-, six-, and 12-month post-transplant mortality in multivariable logistic models. This interaction was most pronounced in patients with a laboratory MELD score <25 transplanted from an ICU, whose adjusted predicted three-, six-, and 12-month post-transplant mortality approximated those of patients with a MELD score ⩾30. Compared to hospitalized patients with a MELD score of 30-34, those with a MELD score ⩾35 in an ICU had significantly increased risk of three-month (OR: 1.54, 95% CI: 1.21-1.97), 6-month (OR: 1.35, 95% CI: 1.09-1.67), and 12-month (OR: 1.25, 95% CI: 1.03-1.52) post-transplant mortality.

DISCUSSION

Pre-transplant ICU status modifies the risk of early post-transplant mortality, independent of MELD score. This should be considered when determining candidacy for transplantation in order to optimize efficient use of a scarce resource.

Liver transplantation in acute on chronic liver failure: challenges and an algorithm for patient selection and management

Acute on chronic liver failure is an entity distinct from acute liver failure and acute decompensation of chronic liver disease. Despite best medical therapy, it is associated with high short-term mortality due to infection and organ failure. Liver transplantation is a potentially curative treatment option that has been shown to have good outcomes in this setting. As there are no reliable ways of predicting which subset of patients will recover spontaneously, early transplantation before establishment of full blown sepsis or organ failure is expected to have favorable outcomes with an acceptable risk. This article reviews current literature on liver transplantation for acute on chronic liver failure, discusses challenges in patient selection, and proposes an algorithm for management.

Outcomes of liver transplantation alone after listing for simultaneous kidney: comparison to simultaneous liver kidney transplantation

BACKGROUND

Data on patient and liver graft survival comparing liver transplantation alone after listing for kidney with simultaneous liver kidney (SLK) transplantation are scanty.

METHODS

United Network Organ Sharing network database (1994-2011) queried for liver transplantation alone after being listed for kidney and SLK transplants.

RESULTS

Of 65,206 first liver transplants, 3549 were listed for simultaneous kidney. Of these, 422 (12%) received only liver (LIST) and differed from SLK recipients for the white race (64% vs. 57%; 0.005), diabetes (27% vs. 37%; P = 0.02), model for end-stage liver disease era (68% vs. 82%; P = 0.0001), serum creatinine (2.9±1.9 vs. 4.3±2.5; P < 0.0001), dialysis (35% vs. 64%; P < 0.0001), and donor risk index (1.6±0.4 vs. 1.5±0.3; P < 0.0001). Overall survival was poorer in the LIST group (55% vs. 76%; P < 0.0001). A higher proportion of patients died within 2 days of transplantation in LIST group (11% vs. 0.5%; P < 0.0001), mostly from cardiovascular causes. After excluding these patients, odds of patient mortality and liver graft loss were about 1.2-fold and twofold higher in the LIST group. A total of 103 (24%) patients needed a renal transplantation in the LIST group with 16 (4%) receiving kidney within first year after transplantation. After excluding patients receiving kidney within first year, about 33% recovered renal function to above estimated GFR of greater than 60 mL per min.

CONCLUSION

Guidelines are needed for patient selection to list for and receipt of simultaneous liver kidney transplantation.

Adoption of MELD score increases the number of liver transplant

Background

Liver transplantation is performed at large transplant centers worldwide as a therapeutic intervention for patients with end-stage liver diseases.

Aim

To analyze the outcomes and incidence of liver transplantation performed at the University of São Paulo and to compare those with the State of São Paulo before and after adoption of the Model for End-Stage Liver Disease (MELD) score.

Method

Evaluation of the number of liver transplantations before and after adoption of the MELD score. Mean values and standard deviations were used to analyze normally distributed variables. The incidence results were compared with those of the State of São Paulo.

Results

There was a high prevalence of male patients, with a predominance of middle-aged. The main indication for liver transplantation was hepatitis C cirrhosis. The mean and median survival rates and overall survival over ten and five years were similar between the groups (p>0.05). The MELD score increased over the course of the study period for patients who underwent liver transplantation (p>0.05). There were an increased number of liver transplants after adoption of the MELD score at this institution and in the State of São Paulo (p<0.001).

Conclusion

The adoption of the MELD score led to increase the number of liver transplants performed in São Paulo.

Update on the management of the liver transplant patient

PURPOSE OF REVIEW

To review and highlight recent literature regarding the medical management of adult patients undergoing liver transplantation.

RECENT FINDINGS

The addition of serum sodium concentration to the model for end-stage liver disease (MELD) score more accurately predicts 90-day waitlist mortality. Predictors of waitlist mortality and posttransplant survival include lower albumin and the presence of ascites, varices, and encephalopathy, as well as more nontraditional predictors such as older age, obesity, frailty, and sarcopenia. Indications for liver transplantation are evolving with the advent of effective therapy for hepatitis C and the increased prevalence of nonalcoholic steatohepatitis. Disparities persist in the current allocation system, including geographic variation and MELD inflation for hepatocellular carcinoma. Share 35 allows for broader regional sharing of organs for patients with the highest need, without detrimental effects on waitlist mortality or survival. Everolimus is a recently approved option for posttransplant immunosuppression that spares renal function.

SUMMARY

The MELD score has enabled the liver transplant community to equitably allocate organs. Recent literature has focused on the limitations of the MELD score and the disparities inherent in the current system. The next steps for liver transplantation will be to develop strategies to further optimize waitlist prioritization and organ allocation.

Renal dysfunction in cirrhosis

PURPOSE OF REVIEW

Renal dysfunction causes significant morbidity in cirrhotic patients. Diagnosis is challenging because it is based on serum creatinine, which is used to calculate estimated glomerular filtration rate, which itself is not an ideal measure of renal function in patients with cirrhosis. Finding the exact cause of renal injury in patients with cirrhosis remains problematic due to the limitations of the current diagnostic tests. The purpose of this review is to highlight studies used to diagnose renal dysfunction in patients with renal dysfunction and review current treatments.

RECENT FINDINGS

New diagnostic criteria and classification of renal dysfunction, especially for acute kidney injury (AKI), have been proposed in hopes of optimizing treatment and improving outcomes. New biomarkers that help to differentiate structural from functional AKI in cirrhotic patients have been developed, but require further investigation. Vasoconstrictors are the most commonly recommended treatment of hepatorenal syndrome (HRS). Given the high mortality in patients with type 1 HRS, all patients with HRS should be evaluated for liver transplantation. When renal dysfunction is considered irreversible, combined liver-kidney transplantation is advised.

SUMMARY

Development of new biomarkers to differentiate the different types of AKI in cirrhosis holds promise. Early intervention in cirrhotic patients with renal dysfunction offers the best hope of improving outcomes.

Incidence and impact of rejection following simultaneous liver-kidney transplantation

BACKGROUND & AIMS

Due to hepatic immunoregulation, simultaneous liver-kidney recipients are presumed to be reasonably protected from kidney rejection and typically receive less immunosuppression compared to kidney transplants alone. However, data to support these conclusions and practices are sparse.

METHODS

We characterized the incidence and types of rejection, graft function, and graft and patient survival in a large population of simultaneous liver-kidney recipients (n=140) with long-term follow-up at our centre (1998-2010).

RESULTS

Acute cellular, antibody-mediated, and chronic kidney rejection was diagnosed in 9 (6.4%), 2 (1.4%), and 1 (0.7%) patient, respectively. Borderline acute kidney rejection was diagnosed in another 16 patients (11.4%). Acute cellular liver rejection occurred in 16 (11.4%) and chronic liver rejection in 4 (2.9%). One-, three-, and five-year patient survival was 86.4%, 78.0%, and 74.0%, respectively, and did not significantly differ by presence or absence of kidney or liver rejection. However, kidney rejection was associated with decreased renal function by lower serum GFR over time (p=0.003).

CONCLUSIONS

Various forms of kidney rejection occurred in ∼20% of our simultaneous liver-kidney recipients and were associated with deterioration in graft function, indicating that the liver may not confer complete protective allo-immunity. More stringent graft monitoring and management strategies, perhaps more akin to kidney transplant alone, should be prospectively studied in simultaneous liver-kidney recipients.

Accuracy of urine collection methods compared to measured GFR in adults with liver disease

BACKGROUND

Assessment of kidney function is necessary to stage kidney disease, dose medications, and to make decisions about organ allocation. Estimating equations that incorporate serum creatinine (SCr) are not consistently reliable. However, assessment of creatinine clearance (CrCl) using 24-hour urine collection methods is also prone to errors. The purpose of this study was to evaluate the accuracy of measured CrCl determined using shorter urine collection times compared to glomerular filtration rate measured by (125)I-iothalamate clearance ((125)I-CL) in patients with liver disease.

METHODS

Adult patients with chronic liver disease were enrolled. All patients received (125)I-iothalamate and had a catheter placed for urine collection. Blood samples were collected at designated times over 8 hours to determine (125)I-CL. CrCl was determined from a 1-hour and a 4-hour urine collection and compared to (125)I-CL.

RESULTS

Characteristics of the eight patients enrolled included age 52 ± 6 years; SCr 1.2 ± 0.4 mg/dL; and Model for End-stage Liver Disease score of 13 ± 3. All patients were Child-Pugh Class B. Mean estimates of kidney function (mean ± SD, mL/min/1.73 m(2)) by method were 74 ± 38 for (125)I-CL, 79 ± 28 for the 1-hour urine collection, and 72 ± 26 for the 4-hour urine collection. Measured CrCl did not differ significantly from (125)I-CL (P = .641 for 1-hour CrCl versus (125)I-CL, and P = 1.0 for the 4-hour CrCl versus (125)I-CL).

CONCLUSION

When urine collection methods are necessary for an individualized assessment of kidney function, shorter collection times can provide accurate results and would be more feasible for the patient.

Review of anesthesia in liver transplantation

Liver transplantation (LT) is a well-accepted treatment modality of many end-stage liver diseases. The main issue in LT is the shortage of deceased donors to accommodate the needs of patients waiting for such transplants. Live donors have tremendously increased the pool of available liver grafts, especially in countries where deceased donors are not common. The main ethical concern of this procedure is the safety of healthy donors, who undergo a major abdominal surgery not for their own health, but to help cure others. The first part of the review concentrates on live donor selection, preanesthetic evaluation, and intraoperative anesthetic care for living liver donors. The second part reviews patient evaluation, intraoperative anesthesia monitoring, and fluid management of the recipient. This review provides up-to-date information to help improve the quality of anesthesia, and contribute to the success of LT and increase the long-term survival of the recipients.

Plasma protein biomarkers enhance the clinical prediction of kidney injury recovery in patients undergoing liver transplantation

Biomarkers predictive of recovery from acute kidney injury (AKI) after liver transplantation (LT) could enhance decision algorithms regarding the need for liver-kidney transplantation or renal sparing regimens. Multianalyte plasma/urine kidney injury protein panels were performed immediately before and 1 month post-LT in an initial test group divided by reversible pre-LT AKI (rAKI = post-LT renal recovery) versus no AKI (nAKI). This was followed by a larger validation set that included an additional group: irreversible pre-LT AKI (iAKI = no post-LT renal recovery). In the test group (n = 16), six pre-LT plasma (not urine) kidney injury proteins (osteopontin [OPN], neutrophil gelatinase-associated lipocalin, cystatin C, trefoil factor 3, tissue inhibitor of metalloproteinase [TIMP]-1, and β-2-microglobulin) were higher in rAKI versus nAKI (P < 0.05) and returned to normal values with renal recovery post-LT. In the validation set (n = 46), a number of proteins were significantly higher in both rAKI and iAKI versus nAKI. However, only pre-LT plasma OPN (P = 0.009) and TIMP-1 (P = 0.019) levels were significantly higher in rAKI versus iAKI. Logistic regression modeling was used to correlate the probability of post-LT rAKI, factoring in both pre-LT protein markers and clinical variables. A combined model including elevated OPN and TIMP-1 levels, age <57, and absence of diabetes had the highest area under the curve of 0.82, compared to protein-only and clinical variable-only models.

CONCLUSION

These data suggest that plasma protein profiles might improve the prediction of pre-LT kidney injury recovery after LT. However, multicenter, prospective studies are needed to validate these findings and ultimately test the value of such protein panels in perioperative management and decision making.

Renal outcomes of simultaneous liver-kidney transplantation compared to liver transplant alone for candidates with renal dysfunction

It is unclear whether a concomitant kidney transplant grants survival benefit to liver transplant (LT) candidates with renal dysfunction (RD). We retrospectively studied LT candidates without RD (n = 714) and LT candidates with RD who underwent either liver transplant alone (RD-LTA; n = 103) or simultaneous liver-kidney transplant (RD-SLKT; n = 68). RD was defined as renal replacement therapy (RRT) requirement or modification of diet in renal disease (MDRD)-glomerular filtration rate (GFR) <25 mL/min/1.73 m(2) . RD-LTAs had worse one-yr post-transplant survival compared to RD-SLKTs (79.6% vs. 91.2%, p = 0.05). However, RD-LTA recipients more often had hepatitis C (60.2% vs. 41.2%, p = 0.004) and more severe liver disease (MELD 37.9 ± 8.1 vs. 32.7 ± 9.1, p = 0.0001). Twenty RD-LTA recipients died in the first post-transplant year. Evaluation of the cause and timing of death relative to native renal recovery revealed that only four RD-LTA recipients might have derived survival benefit from RD-SLKT. Overall, 87% of RD-LTA patients recovered renal function within one month of transplant. One yr after RD-LTA or RD-SLKT, serum creatinine (1.5 ± 1.2 mg/dL vs. 1.4 ± 0.5 mg/dL, p = 0.63) and prevalence of stage 4 or 5 chronic kidney disease (CKD; 5.9% vs. 6.8%, p = 0.11) were comparable. Our series provides little evidence that RD-SLKT would have yielded substantial short-term survival benefit to RD-LTA recipients.

Kidney and liver transplantation in children with fibrocystic liver-kidney disease: data from the US Scientific Registry of Transplant Recipients: 1990-2010

The natural history and survival of children with fibrocystic liver-kidney disease undergoing solid organ transplantation have infrequently been described. We report outcomes in a cohort of US children with fibrocystic liver-kidney disease receiving solid organ transplants over 20 yr. Retrospective cohort study of pediatric transplant recipients with diagnoses of fibrocystic liver-kidney disease from 1/1990 to 3/2010, using data from the SRTR. Subjects were categorized by the first transplanted organ: LT, KT, or SLK. Primary outcomes were death, re-transplant, transplant of the alternate organ, or initiation of dialysis. Seven hundred and sixteen subjects were transplanted in this period. Median age at first transplant was 9.7 yr. Of the LT, 14 (19%) required a second liver transplant at median of 0.2 yr, and five (7%) required kidney transplant or dialysis at a median of 9.0 yr. Of the KT, 188 (31%) required a second kidney transplant or dialysis at a median of 5.9 yr. Twenty-nine (5%) subsequently received liver transplant at a median of 6.0 yr. Among patients in this registry, far more children underwent kidney than liver transplants. The risk of subsequently needing transplantation of an alternate organ was low.

Hepatitis C virus infection and kidney transplantation in 2014: what's new?

Chronic hepatitis C virus (HCV) infection remains an important health problem, which is associated with deleterious consequences in kidney transplant recipients. Besides hepatic complications, several extrahepatic complications contribute to reduced patient and allograft survival in HCV-infected kidney recipients. However, HCV infection should not be considered as a contraindication for kidney transplantation because patient survival is better with transplantation than on dialysis. Treatment of HCV infection is currently interferon-alpha (IFN-α) based, which has been associated with higher renal allograft rejection rates. Therefore, antiviral treatment before transplantation is preferable. As in the nontransplant setting, IFN-free treatment regimens, because of their greater efficacy and reduced toxicity, currently represent promising and attractive therapeutic options after kidney transplantation as well. However, clinical trials will be required to closely evaluate these regimens in kidney recipients. There is also a need for prospective controlled studies to determine the optimal immunosuppressive regimens after transplantation in HCV-infected recipients. Combined kidney and liver transplantation is required in patients with advanced liver cirrhosis. However, in patients with cleared HCV infection and early cirrhosis without portal hypertension, kidney transplantation alone may be considered. There is some agreement about the use of HCV-positive donors in HCV-infected recipients, although data regarding posttransplant survival rates are controversial.

Urinary biomarkers and progression of AKI in patients with cirrhosis

BACKGROUND AND OBJECTIVES

AKI is a common and severe complication in patients with cirrhosis. AKI progression was previously shown to correlate with in-hospital mortality. Therefore, accurately predicting which patients are at highest risk for AKI progression may allow more rapid and targeted treatment. Urinary biomarkers of structural kidney injury associate with AKI progression and mortality in multiple settings of AKI but their prognostic performance in patients with liver cirrhosis is not well known.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A multicenter, prospective cohort study was conducted at four tertiary care United States medical centers between 2009 and 2011. The study comprised patients with cirrhosis and AKI defined by the AKI Network criteria evaluating structural (neutrophil gelatinase-associated lipocalin, IL-18, kidney injury molecule-1 [KIM-1], liver-type fatty acid-binding protein [L-FABP], and albuminuria) and functional (fractional excretion of sodium [FENa]) urinary biomarkers as predictors of AKI progression and in-hospital mortality.

RESULTS

Of 188 patients in the study, 44 (23%) experienced AKI progression alone and 39 (21%) suffered both progression and death during their hospitalization. Neutrophil gelatinase-associated lipocalin, IL-18, KIM-1, L-FABP, and albuminuria were significantly higher in patients with AKI progression and death. These biomarkers were independently associated with this outcome after adjusting for key clinical variables including model of end stage liver disease score, IL-18 (relative risk [RR], 4.09; 95% confidence interval [95% CI], 1.56 to 10.70), KIM-1 (RR, 3.13; 95% CI, 1.20 to 8.17), L-FABP (RR, 3.43; 95% CI, 1.54 to 7.64), and albuminuria (RR, 2.07; 95% CI, 1.05-4.10) per log change. No biomarkers were independently associated with progression without mortality. FENa demonstrated no association with worsening of AKI. When added to a robust clinical model, only IL-18 independently improved risk stratification on a net reclassification index.

CONCLUSIONS

Multiple structural biomarkers of kidney injury, but not FENa, are independently associated with progression of AKI and mortality in patients with cirrhosis. Injury marker levels were similar between those without progression and those with progression alone.

Renal dysfunction in patients with cirrhosis: Where do we stand?

Patients with cirrhosis and renal failure are high-risk patients who can hardly be grouped to form precise instructions for diagnosis and treatment. When it comes to evaluate renal function in patients with cirrhosis, determination of acute kidney injury (AKI), chronic kidney disease (CKD) or AKI on CKD should be made. First it should be excluded the prerenal causes of AKI. All cirrhotic patients should undergo renal ultrasound for measurement of renal resistive index in every stage of liver dysfunction and urine microscopy for differentiation of all causes of AKI. If there is history of dehydration on the ground of normal renal ultrasound and urine microscopy the diuretics should be withdrawn and plasma volume expansion should be tried with albumin. If the patient does not respond, the correct diagnosis is HRS. In case there is recent use of nephrotoxic agents or contrast media and examination shows shock, granular cast in urinary sediment and proteinuria above 0.5 g daily, acute tubular necrosis is the prominent diagnosis. Renal biopsy should be performed when glomerular filtration rate is between 30-60 mL/min and there are signs of parenchymal renal disease. The acute renal function is preferable to be assessed with modified AKIN. Patients with AKIN stage 1 and serum creatinine ≥ 1.5 mg/dL should be at close surveillance. Management options include hemodynamic monitoring and management of fluid balance and infections, potentially driving to HRS. Terlipressin is the treatment of choice in case of established HRS, administered until there are signs of improvement, but not more than two weeks. Midodrine is the alternative for therapy continuation or when terlipressin is unavailable. Norepinephrine has shown similar effect with terlipressin in patients being in Intensive Care Unit, but with much lower cost than that of terlipressin. If the patient meets the requirements for transplantation, dialysis and transjugular intrahepatic portosystemic shunt are the bridging therapies to keep the transplant candidate in the best clinical status. The present review clarifies the latest therapeutic modalities and the proposed recommendations and algorithms in order to be applied in clinical practice.

Acute-on-chronic liver failure

The Model for End-Stage Liver Disease (MELD) has been the single best predictor of outcome of the progression of cirrhosis. Acute-on-chronic liver failure (ACLF) has been proposed as an alternative path in the natural history of cirrhosis. ACLF occurs in patients with chronic liver disease and is characterized by a precipitating event, resulting in acute deterioration in liver function, multiorgan system failure, and high short-term mortality. In this review, the natural course of patients with ACLF, especially as it relates to management of cirrhotic patients on the transplant waiting list, and its impact on liver transplantation outcomes are defined.

Renal dysfunction in end-stage liver disease and post-liver transplant

Renal dysfunction is a frequent complication in patients with end-stage liver disease awaiting orthotopic liver transplantation and in the post-liver transplant period. Although the stereotypical form of renal dysfunction is the hepatorenal syndrome, other causes of acute kidney injury in this population include prerenal azotemia and acute tubular necrosis. Renal injury in a patient with cirrhosis is associated with a poor prognosis.

Glomerular filtration rate equations for liver-kidney transplantation in patients with cirrhosis: validation of current recommendations

Simultaneous liver and kidney transplantation (SLKT) remains the procedure of choice for patients with both endstage liver disease and kidney failure. Stringent guidelines are needed to avoid unnecessary kidney transplantation. A recent consensus meeting proposed criteria based on the Modified Diet in Renal Disease (MDRD)-6 equation to estimate glomerular filtration rate (GFR). The aims of this study were to compare GFR equations to true GFR in candidates for liver transplantation (LT) and to determine the impact of inaccuracies on the current guidelines for SLKT. Three hundred stable cirrhosis patients evaluated for LT were studied. All patients had iohexol clearance to measure GFR at evaluation under stable conditions. Measured GFR (mGFR) was compared to MDRD-4, MDRD-6, and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. MDRD-6 was the most accurate equation to predict GFR. In the 290 patients with mGFR >30 mL/min/1.73 m(2), 15 patients (7%) had estimated GFR (eGFR) ≤40 mL/min/1.73 m(2) based on the MDRD-6 equation, defining "discordant" patients. Among them, two underwent SLKT and 13 underwent LT alone. None of those who survived more than 1 year after LT alone (n = 8) developed renal dysfunction thereafter. In multivariate analysis, discordant patients were older (P = 0.03) and had lower sodium level (P = 0.02).

CONCLUSION

The MDRD-6 equation was superior to other equations at identifying cirrhosis patients with true GFR <30 mL/min/1.73 m(2). However, the MDRD-6 equation also tended to underestimate renal function in a subgroup of patients with true GFR >30 mL/min/1.73 m(2), with a potential risk of unnecessary kidney transplantation if applying current U.S. recommendations for SLKT.

Review article: advances in the management of patients with cirrhosis and portal hypertension-related renal dysfunction

BACKGROUND

In cirrhosis, portal hypertension is associated with a spectrum of renal dysfunction that has significant implications for morbidity and mortality.

AIM

To discuss recent progress in the patho-physiological mechanisms and therapeutic options for portal hypertension-related renal dysfunction.

METHODS

A literature search using Pubmed was performed.

RESULTS

Portal hypertension-related renal dysfunction occurs in the setting of marked neuro-humoral and circulatory derangement. A systemic inflammatory response is a pathogenetic factor in advanced disease. Such physiological changes render the individual vulnerable to further deterioration of renal function. Patients are primed to develop acute kidney injury when exposed to additional 'hits', such as sepsis. Recent progress has been made regarding our understanding of the aetiopathogenesis. However, treatment options once hepatorenal syndrome develops are limited, and prognosis remains poor. Various strategies to prevent acute kidney injury are suggested.

CONCLUSION

Prevention of acute kidney injury in high risk patients with cirrhosis and portal hypertension-related renal dysfunction should be a clinical priority.

Excessive immunosuppression as a potential cause of poor survival in simultaneous liver/kidney transplantation for hepatitis C

Appropriate recipient selection of simultaneous liver/kidney transplantation (SLKT) remains controversial. In particular, data on liver graft survival in hepatitis C virus-infected (HCV+) SLKT recipients are lacking. We conducted a single-center, retrospective study of HCV+ SLKT recipients (N = 25) in comparison with HCV- SLKT (N = 26) and HCV+ liver transplantation alone (LTA, N = 296). Despite backgrounds of HCV+ and HCV- SLKT being similar, HCV+ SLKT demonstrated significantly impaired 5-year liver graft survival of 35% (HCV- SLKT, 79%, P = 0.004). Compared with HCV+ LTA, induction immunosuppression was more frequently used in HCV+ SLKT. Five-year liver graft survival rate for HCV+ SLKT was significantly lower than that for LTA (35% vs. 74%, respectively, P < 0.001). Adjusted hazard ratio of liver graft loss in HCV+ SLKT was 4.9 (95% confidence interval 2.0-12.1, P = 0.001). HCV+ SLKT recipients were more likely to succumb to recurrent HCV and sepsis compared with LTA (32% vs. 8.8%, P < 0.001 and 24% vs. 8.8%, P = 0.030, respectively). Ten HCV+ SLKT recipients underwent anti-HCV therapy for recurrent HCV; only 1 achieved sustained virological response. HCV+ SLKT is associated with significantly decreased long-term prognosis compared with HCV- SLKT and HCV+ LTA.

First successful case of simultaneous liver and kidney transplantation for patients with chronic liver and renal failure in Japan

Establishment of a preferential liver allocation rule for simultaneous liver and kidney transplantation (SLK) and revisions of laws regarding organ transplants from deceased donors have paved the way for SLK in Japan. Very few cases of SLK have been attempted in Japan, and no such recipients have survived for longer than 40 days. The present report describes a case of a 50-year-old woman who had undergone living donor liver transplantation at the age of 38 years for management of post-partum liver failure. After the first transplant surgery, she developed hepatic vein stenosis and severe hypersplenism requiring splenectomy. She was then initiated on hemodialysis (HD) due to the deterioration of renal function after insertion of a hepatic vein stent. She was listed as a candidate for SLK in 2011 because she required frequent plasma exchange for hepatic coma. When her Model for End-stage Liver Disease score reached 46, the new liver was donated 46 days after registration. The reduced trisegment liver and the kidney grafts were simultaneously transplanted under veno-venous bypass and intraoperative HD. The hepatic artery was reconstructed prior to portal reconstruction in order to shorten anhepatic time. Although she developed subcapsular bleeding caused by hepatic contusion on the next day, subsequent hemostasis was obtained by transcatheter embolization. Thereafter, her recovery was uneventful, except for mild rejection and renal tubular acidosis of the kidney graft. This case highlights the need to establish Japanese criteria for SLK.

Heart and combined heart-kidney transplantation in patients with concomitant renal insufficiency and end-stage heart failure

In patients with end-stage heart failure (ESHF) who are candidates for isolated heart transplant (HRT), dialysis dependence (DD) is considered an indication for combined heart-kidney transplantation (HKT). HKT remains controversial in ESHF transplant candidates with nondialysis-dependent renal insufficiency (NDDRI). Using United Network for Organ Sharing data, we examined the cumulative incidences of transplant and mortality in patients with DD and NDDRI waitlisted for HKT or HRT. In all groups, 3-month waitlist mortality was dismal: 31% and 21% for HRT- and HKT-listed patients with DD and 12% and 7% for HRT- and HKT-listed patients with NDDRI. Five-year posttransplant survival was improved in HKT recipients compared with HRT recipients for both patients with DD (73% vs. 51%, p<0.001) and NDDRI (80% vs. 69%, p<0.001). Likewise, multivariable analysis associated HKT with better outcomes than HRT in HKT-listed patients, although both improved survival. These data argue strongly for HKT in ESHF transplant candidates with DD. However, in patients with NDDRI, HKT must be weighed against the possibility of renal recovery with isolated HRT. Whether HRT (followed by a staged kidney transplant in patients who do not recover renal function after HRT), as opposed to HKT, maximizes organ benefit for patients with NDDRI and ESHF requires assessment. Nevertheless, given their dismal waitlist outcomes and excellent posttransplant results, we suggest that patients with DD and NDDRI with ESHF be considered for early listing and transplant.

Geographic determinants of access to pediatric deceased donor kidney transplantation

Children receive priority in the allocation of deceased donor kidneys for transplantation in the United States, but because allocation begins locally, geographic differences in population and organ supply may enable variation in pediatric access to transplantation. We assembled a cohort of 3764 individual listings for pediatric kidney transplantation in 2005-2010. For each donor service area, we assigned a category of short (<180 days), medium (181-270 days), or long (>270 days) median waiting time and calculated the ratio of pediatric-quality kidneys to pediatric candidates and the percentage of these kidneys locally diverted to adults. We used multivariable Cox regression analyses to examine the association between donor service area characteristics and time to deceased donor kidney transplantation. The Kaplan-Meier estimate of median waiting time to transplantation was 284 days (95% confidence interval, 263 to 300 days) and varied from 14 to 1313 days across donor service areas. Overall, 29% of pediatric-quality kidneys were locally diverted to adults. Compared with areas with short waiting times, areas with long waiting times had a lower ratio of pediatric-quality kidneys to candidates (3.1 versus 5.9; P<0.001) and more diversions to adults (31% versus 27%; P<0.001). In multivariable regression, a lower kidney to candidate ratio remained associated with longer waiting time (hazard ratio, 0.56 for areas with <2:1 versus reference areas with ≥5:1 kidneys/candidates; P<0.01). Large geographic variation in waiting time for pediatric deceased donor kidney transplantation exists and is highly associated with local supply and demand factors. Future organ allocation policy should address this geographic inequity.

Revisiting multi-organ transplantation in the setting of scarcity

In the setting of organ scarcity, the ethics of multi-organ transplantation (MOT) deserve new examination. MOT offers substantial benefits to certain recipients, including avoiding serial surgeries. However, MOT candidates in the United States commonly receive priority for their nonprimary organ over many individuals who need that organ, which may undermine equity. The absence of standard criteria for MOT eligibility also enables large and unfair regional variation in MOT, such as simultaneous liver-kidney transplantation. Unfortunately, MOT may also undermine utility (optimal patient and graft survival) in circumstances where providing multiple organs to one person fails to achieve the greater collective benefit attained by providing transplants to multiple people. Policy reforms should include the adoption of minimal clinical criteria for MOT candidacy with the attendant goal of decreasing regional variation in MOT. In the future, these minimal criteria can be revised to accommodate new research about which patients derive the most benefit from MOT. Incentives to perform MOT should also be reduced, such as by including MOT outcomes in center-specific reports. These reforms run the risk that the transplant community could be perceived as abandoning MOT candidates, but offer an opportunity to align transplant practice and ethical principles.

Management of acute kidney injury in cirrhosis

Acute kidney injury (AKI) is a relatively frequent problem, occurring in approximately 20 % of hospitalized patients with cirrhosis. Although serum creatinine (S Cr) is the most commonly used method to determine AKI because of easy availability and low cost, practically it underestimates the extent of kidney injury in patients with chronic liver disease. AKI is defined as an abrupt rise in S Cr of 0.3 mg/dl or more (>26.4 mmol/l) or an increase of 150 % or more (1.5-fold) from baseline. The cause of AKI in cirrhosis is multifactorial and is unique in terms of pathogenesis. The most common causes of AKI in cirrhosis can be subdivided into either functional or structural. The functional group includes volume-responsive (prerenal azotemia) and volume-unresponsive states (hepatorenal syndrome). Volume responsive is the most common type of AKI due to frequent use of diuretics, large volume abdominal paracentesis and gastrointestinal bleeding in patients with liver disease. The structural causes include acute tubular necrosis, tubulointerstitial and glomerular diseases. Patients with decompensated cirrhosis are in a vasodilatory state leading to a decrease in effective arterial blood volume, predisposing to AKI. Therefore, management of AKI depends on the underlying cause, and therapy should be directed toward removal of the cause. The outcome in cirrhosis when patients are on dialysis is very dismal. Every effort should be made to prevent AKI.

Model for End-stage Liver Disease

Model for end-stage liver disease (MELD) score, initially developed to predict survival following transjugular intrahepatic portosystemic shunt was subsequently found to be accurate predictor of mortality amongst patents with end-stage liver disease. Since 2002, MELD score using 3 objective variables (serum bilirubin, serum creatinine, and institutional normalized ratio) has been used worldwide for listing and transplanting patients with end-stage liver disease allowing transplanting sicker patients first irrespective of the wait time on the list. MELD score has also been shown to be accurate predictor of survival amongst patients with alcoholic hepatitis, following variceal hemorrhage, infections in cirrhosis, after surgery in patients with cirrhosis including liver resection, trauma, and hepatorenal syndrome (HRS). Although, MELD score is closest to the ideal score, there are some limitations including its inaccuracy in predicting survival in 15-20% cases. Over the last decade, many efforts have been made to further improve and refine MELD score. Until, a better score is developed, liver allocation would continue based on the currently used MELD score.

Short-term pretransplant renal replacement therapy and renal nonrecovery after liver transplantation alone

BACKGROUND AND OBJECTIVES

Candidates with AKI including hepatorenal syndrome often recover renal function after successful liver transplantation (LT). This study examined the incidence and risk factors associated with renal nonrecovery within 6 months of LT alone among those receiving acute renal replacement therapy (RRT) before LT.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Scientific Registry of Transplant Recipients data were linked with Centers for Medicare and Medicaid Services ESRD data for 2112 adult deceased-donor LT-alone recipients who received acute RRT for ≤90 days before LT (February 28, 2002 to August 31, 2010). Primary outcome was renal nonrecovery (post-LT ESRD), defined as transition to chronic dialysis or waitlisting or receipt of kidney transplant within 6 months of LT. Cumulative incidence of renal nonrecovery was calculated using competing risk analysis. Cox regression identified recipient and donor predictors of renal nonrecovery.

RESULTS

The cumulative incidence of renal nonrecovery after LT alone among those receiving the pre-LT acute RRT was 8.9%. Adjusted renal nonrecovery risk increased by 3.6% per day of pre-LT RRT (P<0.001). Age at LT per 5 years (P=0.02), previous-LT (P=0.01), and pre-LT diabetes (P<0.001) were significant risk factors of renal nonrecovery. Twenty-one percent of recipients died within 6 months of LT. Duration of pretransplant RRT did not predict 6-month post-transplant mortality.

CONCLUSIONS

Among recipients on acute RRT before LT who survived after LT alone, the majority recovered their renal function within 6 months of LT. Longer pre-LT RRT duration, advanced age, diabetes, and re-LT were significantly associated with increased risk of renal nonrecovery.