Serum bile acids as a prognostic biomarker in biliary atresia following Kasai portoenterostomy

BACKGROUND AND AIMS

In biliary atresia, serum bilirubin is commonly used to predict outcomes after Kasai portoenterostomy (KP). Infants with persistently high levels invariably need liver transplant, but those achieving normalized levels have a less certain disease course. We hypothesized that serum bile acid levels could help predict outcomes in the latter group.

APPROACH AND RESULTS

Participants with biliary atresia from the Childhood Liver Disease Research Network were included if they had normalized bilirubin levels 6 months after KP and stored serum samples from the 6-month post-KP clinic visit ( n  = 137). Bile acids were measured from the stored serum samples and used to divide participants into ≤40 μmol/L ( n  = 43) or >40 μmol/L ( n  = 94) groups. At 2 years of age, the ≤40 μmol/L compared with >40 μmol/L group had significantly lower total bilirubin, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, bile acids, and spleen size, as well as significantly higher albumin and platelet counts. Furthermore, during 734 person-years of follow-up, those in the ≤40 μmol/L group were significantly less likely to develop splenomegaly, ascites, gastrointestinal bleeding, or clinically evident portal hypertension. The ≤40 μmol/L group had a 10-year cumulative incidence of liver transplant/death of 8.5% (95% CI: 1.1%-26.1%), compared with 42.9% (95% CI: 28.6%-56.4%) for the >40 μmol/L group ( p  = 0.001).

CONCLUSIONS

Serum bile acid levels may be a useful prognostic biomarker for infants achieving normalized bilirubin levels after KP.

Serum biomarkers correlated with liver stiffness assessed in a multicenter study of pediatric cholestatic liver disease

BACKGROUND AND AIMS

Detailed investigation of the biological pathways leading to hepatic fibrosis and identification of liver fibrosis biomarkers may facilitate early interventions for pediatric cholestasis.

APPROACH AND RESULTS

A targeted enzyme-linked immunosorbent assay-based panel of nine biomarkers (lysyl oxidase, tissue inhibitor matrix metalloproteinase (MMP) 1, connective tissue growth factor [CTGF], IL-8, endoglin, periostin, Mac-2-binding protein, MMP-3, and MMP-7) was examined in children with biliary atresia (BA; n = 187), alpha-1 antitrypsin deficiency (A1AT; n = 78), and Alagille syndrome (ALGS; n = 65) and correlated with liver stiffness (LSM) and biochemical measures of liver disease. Median age and LSM were 9 years and 9.5 kPa. After adjusting for covariates, there were positive correlations among LSM and endoglin ( p = 0.04) and IL-8 ( p < 0.001) and MMP-7 ( p < 0.001) in participants with BA. The best prediction model for LSM in BA using clinical and lab measurements had an R2 = 0.437; adding IL-8 and MMP-7 improved R2 to 0.523 and 0.526 (both p < 0.0001). In participants with A1AT, CTGF and LSM were negatively correlated ( p = 0.004); adding CTGF to an LSM prediction model improved R2 from 0.524 to 0.577 ( p = 0.0033). Biomarkers did not correlate with LSM in ALGS. A significant number of biomarker/lab correlations were found in participants with BA but not those with A1AT or ALGS.

CONCLUSIONS

Endoglin, IL-8, and MMP-7 significantly correlate with increased LSM in children with BA, whereas CTGF inversely correlates with LSM in participants with A1AT; these biomarkers appear to enhance prediction of LSM beyond clinical tests. Future disease-specific investigations of change in these biomarkers over time and as predictors of clinical outcomes will be important.

Comparing clinical bladder diaries and recalled patient reports for measuring lower urinary tract symptoms in the symptoms of Lower Urinary Tract Dysfunction Research Network (LURN)

PURPOSE

Bladder diaries are a key source of information about lower urinary tract symptoms (LUTS); however, many patients do not complete them as instructed. Questionnaire-based patient-reported outcome measures (PROMs) are another option for reporting LUTS but may have recall bias. We assessed the strength of the associations between PROMs and a 3-day bladder diary.

MATERIALS AND METHODS

Symptomatic adults from 6 tertiary care sites completed a 3-day paper bladder diary and 3-, 7-, and 30-day electronic PROMs. We assessed the linear associations between mapped pairs of diary variables and responses to PROM items using biserial and polyserial correlation coefficients with 95% confidence intervals.

RESULTS

Of 290 enrolled participants, 175 (60%) completed the bladder diary as instructed and at least one corresponding PROM. Linear associations were strongest between the diary and 3-day recall of daytime frequency (r = 0.75) and nighttime frequency (r = 0.69), followed by voids with urgency sensations (r = 0.62), and an item reporting any incontinence (r = 0.56). Linear associations between bladder diary and specific incontinence variables (e.g., stress, urgency) were low to negligible (ranging from r = 0.16-0.39). Linear associations were consistent across the 3-, 7-, and 30-day recall periods.

CONCLUSIONS

Missing and unusable bladder diary data were common, highlighting the patient burden associated with this method of data collection. A questionnaire-based PROM is a reasonable alternative to a diary for reporting voiding frequency and may offer an easier option for reporting some symptoms.

Nonfasted Liver Stiffness Correlates with Liver Disease Parameters and Portal Hypertension in Pediatric Cholestatic Liver Disease

Elastographic measurement of liver stiffness is of growing importance in the assessment of liver disease. Pediatric experiences with this technique are primarily single center and limited in scope. The Childhood Liver Disease Research Network provided a unique opportunity to assess elastography in a well-characterized multi-institutional cohort. Children with biliary atresia (BA), alpha-1 antitrypsin deficiency (A1ATD), or Alagille syndrome (ALGS) followed in a prospective longitudinal network study were eligible for enrollment in a prospective investigation of transient elastography (FibroScan). Studies were performed in participants who were nonfasted and nonsedated. Liver stiffness measurements (LSMs) were correlated with standard clinical and biochemical parameters of liver disease along with a research definition of clinically evident portal hypertension (CEPH) graded as absent, possible, or definite. Between November 2016 and August 2019, 550 participants with a mean age of 8.8 years were enrolled, 458 of whom had valid LSMs (BA, n = 254; A1ATD, n = 104; ALGS, n = 100). Invalid scans were more common in participants <2 years old. There was a positive correlation between LSM and total bilirubin, international normalized ratio (INR), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), GGT to platelet ratio (GPR), pediatric end-stage liver disease score, AST to platelet ratio index, and spleen size, and a negative correlation with albumin and platelet count in BA, with similar correlations for A1ATD (except AST, ALT, and albumin) and ALGS (except for INR, GGT, GPR, and ALT). Possible or definite CEPH was more common in BA compared to ALGS and A1ATD. LSM was greater in definite versus absent CEPH in all three diseases. Disease-specific clinical and biochemical characteristics of the different CEPH grades were observed. Conclusion: It is feasible to obtain LSMs in children, especially over the age of 2 years. LSM correlates with liver parameters and portal hypertension, although disease-specific patterns exist.

Best practices to optimize utilization of the National Living Donor Assistance Center for the financial assistance of living organ donors

Living organ donors face direct costs when donating an organ, including transportation, lodging, meals, and lost wages. For those most in need, the National Living Donor Assistance Center (NLDAC) provides reimbursement to defray travel and subsistence costs associated with living donor evaluation, surgery, and follow-up. While this program currently supports 9% of all US living donors, there is tremendous variability in its utilization across US transplant centers, which may limit patient access to living donor transplantation. Based on feedback from the transplant community, NLDAC convened a Best Practices Workshop on August 2, 2018, in Arlington, VA, to identify strategies to optimize transplant program utilization of this valuable resource. Attendees included team members from transplant centers that are high NLDAC users; the NLDAC program team; and Advisory Group members. After a robust review of NLDAC data and engagement in group discussions, the workgroup identified concrete best practices for administrative and transplant center leadership involvement; for individuals filing NLDAC applications at transplant centers; and to improve patient education about potential financial barriers to living organ donation. Multiple opportunities were identified for intervention to increase transplant programs' NLDAC utilization and reduce financial burdens inhibiting expansion of living donor transplantation in the United States.

Symptom Based Clustering of Men in the LURN Observational Cohort Study

PURPOSE

Conventional classification of patients with lower urinary tract symptoms into diagnostic categories based on a predefined symptom complex or predominant symptom appears inadequate. This is due to the frequent presentation of patients with multiple urinary symptoms which could not be perfectly categorized into traditional diagnostic groups. We used a novel clustering method to identify subtypes of male patients with lower urinary tract symptoms based on detailed multisymptom information.

MATERIALS AND METHODS

We analyzed baseline data on 503 care seeking men in the LURN (Symptoms of Lower Urinary Tract Dysfunction Research Network) Observational Cohort Study. Symptoms and symptom severity were assessed using the LUTS (Lower Urinary Tract Symptoms) Tool and the AUA SI (American Urological Association Symptom Index), which include a total of 52 questions. We used a resampling based consensus clustering algorithm to identify patient subtypes with distinct symptom signatures.

RESULTS

Four distinct symptom clusters were identified. The 166 patients in cluster M1 had predominant symptoms of frequency, nocturia, hesitancy, straining, weak stream, intermittency and incomplete bladder emptying suggestive of bladder outlet obstruction. The 93 patients in cluster M2 mainly endorsed post-micturition symptoms (eg post-void dribbling and post-void leakage) with some weak stream. The 114 patients in cluster M3 reported mostly urinary frequency without incontinence. The 130 patients in cluster M4 reported severe frequency, urgency and urgency incontinence. Most other urinary symptoms statistically differed between cluster pairs. Patient reported outcomes of bowel symptoms, mental health, sleep dysfunction, erectile function and urological pain significantly differed across the clusters.

CONCLUSIONS

We identified 4 data derived clusters among men seeking care for lower urinary tract symptoms. The clusters differed from traditional diagnostic categories. Further subtype refinement will be done to incorporate clinical data and nonurinary patient reported outcomes.

Clustering of the structures by using "snakes-&-dragons" approach, or correlation matrix as a signal

Biological, ecological, social, and technological systems are complex structures with multiple interacting parts, often represented by networks. Correlation matrices describing interdependency of the variables in such structures provide key information for comparison and classification of such systems. Classification based on correlation matrices could supplement or improve classification based on variable values, since the former reveals similarities in system structures, while the latter relies on the similarities in system states. Importantly, this approach of clustering correlation matrices is different from clustering elements of the correlation matrices, because our goal is to compare and cluster multiple networks-not the nodes within the networks. A novel approach for clustering correlation matrices, named "snakes-&-dragons," is introduced and illustrated by examples from neuroscience, human microbiome, and macroeconomics.

Are three-day voiding diaries feasible and reliable? Results from the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN) cohort

AIMS

The aims of this study were to assess the completeness of voiding diaries in a research context and to correlate diary data with patient-reported questionnaires.

METHODS

Men and women enrolled in the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN) were given a 3-day voiding and fluid-intake diary to fill-out. Diaries were assessed for completeness and intake-output imbalances. They were assigned to one of four categories based on a percentage of missing data and fluid imbalance: no diary submitted, unusable (>40% missing void or intake volumes, or unphysiological fluid imbalance), usable but not complete, and complete.

RESULTS

A total of 1064 participants were enrolled and 85% (n = 902) returned the bladder diary. Of the diaries returned, 94% (n = 845) had data on three separate days, 87% (n = 786) had no missing intake volumes, 61% (n = 547) had no missing voided volumes, and 70% (n = 635) had a fluid imbalance within 3 L across the 3-day time period, resulting in 50% (n = 448) of participants with 100% complete diaries. Younger age was associated with a higher likelihood of not submitting a diary, or submitting an unusable diary. Women had a higher likelihood of submitting an unusable diary or a usable but incomplete diary.

CONCLUSION

Overall, 50% of LURN participants returned voiding diaries with perfectly complete data. Incomplete data for voided volumes was the most common deficiency. There was only a moderate correlation between diary data and questionnaire responses, indicating that diaries are a source of unique information.

Life and expectations post-kidney transplant: a qualitative analysis of patient responses

BACKGROUND

The effect of a kidney transplant on a recipient extends beyond the restoration of kidney function. However, there is limited qualitative analysis of recipient perspectives on life following transplantation, particularly in the United States. To understand the full patient experience, it is necessary to understand recipient views on life adjustments after kidney transplantation, medical management, and quality of life. This could lead to improvements in recipient care and sense of well-being.

METHODS

We conducted a paper-based survey from March 23 to October 1, 2015 of 476 kidney transplant recipients at the University of Michigan Health System in Ann Arbor, Michigan. We analyzed their open-ended responses using qualitative research methods. This is a companion analysis to a previous quantitative report on the closed-ended responses to that survey.

RESULTS

Common themes relating to changes following transplantation included: improvements in quality of life, a return to normalcy, better health and more energy. Concerns included: duration of graft survival, fears about one day returning to dialysis or needing to undergo another kidney transplant, comorbidities, future quality of life, and the cost and quality of their healthcare. Many recipients were grateful for their transplant, but some were anxious about the burdens transplantation placed on their loved ones.

CONCLUSIONS

While most recipients reported meaningful improvements in health and lifestyle after kidney transplantation, a minority of participants experienced declines in energy or health status. Worries about how long the transplant will function, future health, and cost and quality of healthcare are prevalent. Future research could study the effects of providing additional information, programs, and interventions following transplantation that target these concerns. This may better prepare and support kidney recipients and lead to improvements in the patient experience.

Comparison of patient and provider goals, expectations, and experiences following kidney transplantation

OBJECTIVE

This study examined whether kidney transplant recipients' post-transplant goals and expectations align with those as perceived by their healthcare providers.

METHODS

Post-transplant goals and expectations across four domains were assessed via a descriptive survey of healthcare providers (N=72) and kidney transplant recipients (N=476) at the University of Michigan from March 23 - October 1, 2015. Demographic and transplant-related data were collected via a retrospective review of medical records, and survey responses were compared using Chi-square tests, Wilcoxon two-sample tests, and logistic regression.

RESULTS

Patients expressed higher quality of life (mean Neuro-QOL T-score 60.2 vs. 52.7), were less likely to report that they were currently experiencing complications (11% vs. 24%), and anticipated their transplants to last longer (median 25 vs. 15 years) and to live longer (median 80 vs. 71 years) than providers expected for their typical patient. However, provider perceptions of patients' future ability to feel well, perform daily activities and work were significantly higher than those expressed by patients (all p<0.05).

CONCLUSION

Kidney transplant patient and provider expectations differ in significant ways.

PRACTICE IMPLICATIONS

Identified areas of discordance may provide opportunities for patients and providers to better evaluate treatment option tradeoffs in post-transplant clinical interactions.

Symptom Based Clustering of Women in the LURN Observational Cohort Study

PURPOSE

Women with lower urinary tract symptoms are often diagnosed based on a predefined symptom complex or a predominant symptom. There are many limitations to this paradigm as often patients present with multiple urinary symptoms which do not perfectly fit the preestablished diagnoses. We used cluster analysis to identify novel, symptom based subtypes of women with lower urinary tract symptoms.

MATERIALS AND METHODS

We analyzed baseline urinary symptom questionnaire data obtained from 545 care seeking female participants enrolled in the LURN (Symptoms of Lower Urinary Tract Dysfunction Research Network) Observational Cohort Study. Symptoms were measured with the LUTS (lower urinary tract symptoms) Tool and the AUA SI (American Urological Association Symptom Index), and analyzed using a probability based consensus clustering algorithm.

RESULTS

Four clusters were identified. The 138 women in cluster F1 did not report incontinence but experienced post-void dribbling, frequency and voiding symptoms. The 80 women in cluster F2 reported urgency incontinence as well as urgency and frequency but minimal voiding symptoms or stress incontinence. Cluster F3 included 244 women who reported all types of incontinence, urgency, frequency and mild voiding symptoms. The 83 women in cluster F4 reported all lower urinary tract symptoms at uniformly high levels. All but 2 of 44 LUTS Tool and 8 AUA SI questions significantly differed between at least 2 clusters (p <0.05). All clusters contained at least 1 member from each conventional group, including continence, and stress, urgency, mixed and other incontinence.

CONCLUSIONS

Women seeking care for lower urinary tract symptoms cluster into 4 distinct symptom groups which differ from conventional clinical diagnostic groups. Further validation is needed to determine whether management improves using this new classification.

Kidney transplant graft outcomes in 379 257 recipients on 3 continents

Kidney transplant outcomes that vary by program or geopolitical unit may result from variability in practice patterns or health care delivery systems. In this collaborative study, we compared kidney graft outcomes among 4 countries (United States, United Kingdom, Australia, and New Zealand) on 3 continents. We analyzed transplant and follow-up registry data from 1988-2014 for 379 257 recipients of first kidney-only transplants using Cox regression. Compared to the United States, 1-year adjusted graft failure risk was significantly higher in the United Kingdom (hazard ratio [HR] 1.22, 95% confidence interval [CI] 1.18-1.26, P < .001) and New Zealand (hazard ratio [HR] 1.29, 95% confidence interval [CI] 1.14-1.46, P < .001), but lower in Australia (HR 0.90, 95% CI 0.84-0.96, P = .001). In contrast, long-term adjusted graft failure risk (conditional on 1-year function) was significantly higher in the United States compared to Australia, New Zealand, and the United Kingdom (HR 0.74, 0.75, and 0.74, respectively; each P < .001). Thus long-term kidney graft outcomes are approximately 25% worse in the United States than in 3 other countries with well-developed kidney transplant systems. Case mix differences and residual confounding from unmeasured factors were found to be unlikely explanations. These findings suggest that identification of potentially modifiable country-specific differences in care delivery and/or practice patterns should be sought.

Return on investment for financial assistance for living kidney donors in the United States

BACKGROUND

The National Living Donor Assistance Center (NLDAC) enables living donor kidney transplants through financial assistance of living donors, but its return on investment (ROI) through savings on dialysis costs remains unknown.

METHODS

We retrospectively reviewed 2012-2015 data from NLDAC, the United States Renal Data System, and the Scientific Registry of Transplant Recipients to construct 1-, 3-, and 5-year ROI models based on NLDAC applications and national dialysis and transplant cost data. ROI was defined as state-specific federal dialysis cost minus (NLDAC program costs plus state-specific transplant cost), adjusted for median waiting time (WT).

RESULTS

A total of 2425 NLDAC applications were approved, and NLDAC costs were USD $6.76 million. Median donor age was 41 years, 66.1% were female, and median income was $33 759; 43.6% were evaluated at centers with WT >72 months. Median dialysis cost/patient-year was $81 485 (IQR $74 489-$89 802). Median kidney transplant cost/patient-year was $30 101 (IQR $26 832-$33 916). Overall, ROI varied from 5.1-fold (1-year) to 28.2-fold (5-year), resulting in $256 million in savings. Higher ROI was significantly associated with high WT, larger dialysis and transplant costs differences, and more NLDAC applicants completing the donation process.

CONCLUSIONS

Financial support for donor out-of-pocket expenses produces dramatic federal savings through incremental living donor kidney transplants.

Estimating the effect of a rare time-dependent treatment on the recurrent event rate

In many observational studies, the objective is to estimate the effect of treatment or state-change on the recurrent event rate. If treatment is assigned after the start of follow-up, traditional methods (eg, adjustment for baseline-only covariates or fully conditional adjustment for time-dependent covariates) may give biased results. We propose a two-stage modeling approach using the method of sequential stratification to accurately estimate the effect of a time-dependent treatment on the recurrent event rate. At the first stage, we estimate the pretreatment recurrent event trajectory using a proportional rates model censored at the time of treatment. Prognostic scores are estimated from the linear predictor of this model and used to match treated patients to as yet untreated controls based on prognostic score at the time of treatment for the index patient. The final model is stratified on matched sets and compares the posttreatment recurrent event rate to the recurrent event rate of the matched controls. We demonstrate through simulation that bias due to dependent censoring is negligible, provided the treatment frequency is low, and we investigate a threshold at which correction for dependent censoring is needed. The method is applied to liver transplant (LT), where we estimate the effect of development of post-LT End Stage Renal Disease (ESRD) on rate of days hospitalized.

Bowel function, sexual function, and symptoms of pelvic organ prolapse in women with and without urinary incontinence

AIMS

Bowel symptoms, pelvic organ prolapse, and sexual dysfunction are common, but their frequency among women with lower urinary tract symptoms (LUTS) has not been well described. Our aims were to describe pelvic floor symptoms among women with and without urinary incontinence (UI) and among subtypes of UI.

METHODS

Women with LUTS seeking care at six U.S. tertiary care centers enrolled in prospective cohort study were studied. At baseline, participants completed the Pelvic Floor Distress Inventory (PFDI-20), Pelvic Organ Prolapse/Incontinence Sexual Questionnaire (PISQ-IR), and PROMIS GI Diarrhea, Constipation, and Fecal Incontinence Scales.

RESULTS

Mean age among the 510 women was 56.4 ± 14.4 years. Women who reported UI (n = 420) had more diarrhea and constipation symptoms (mean scores 49.5 vs 46.2 [P = 0.01] and 51.9 vs 48.4 [P < 0.01], respectively) at baseline. Among sexually active women, mean PISQ-IR subscale scores were lower among those with UI (condition specific: 89.8 vs 96.7, P < 0.01; condition impact: 79.8 vs 92.5, P < 0.01). Women with mixed urinary incontinence (MUI) (n = 240) reported more prolapse symptoms, fecal incontinence, and worse sexual function compared to those with stress urinary incontinence (SUI) and urgency urinary incontinence (UUI).

CONCLUSIONS

Women presenting with LUTS with UI reported significantly worse constipation, diarrhea, fecal incontinence, and sexual function compared to women without UI. In women with UI, sexual function and pelvic organ prolapse (POP) symptoms were worse in those with MUI compared to SUI and UUI.

Biliary reconstructive techniques and associated anatomic variants in adult living donor liver transplantations: The adult-to-adult living donor liver transplantation cohort study experience

Living donor liver transplantation (LDLT) is a technically demanding endeavor, requiring command of the complex anatomy of partial liver grafts. We examined the influence of anatomic variation and reconstruction techniques on surgical outcomes and graft survival in the 9-center Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). Data from 272 adult LDLT recipients (2011-2015) included details on anatomic characteristics and types of intraoperative biliary reconstruction. Associations were tested between reconstruction technique and complications, which included first biliary complication (BC; leak, stricture, or biloma) and first vascular complication (VC; hepatic artery thrombosis [HAT] or portal vein thrombosis [PVT]). Time to patient death, graft failure, and complications were estimated using Kaplan-Meier curves and tested with log-rank tests. Median posttransplant follow-up was 1.2 years. Associations were found between the type of biliary reconstruction and the incidence of VC (P = 0.03) and BC (P = 0.05). Recipients with Roux-en-Y hepaticojejunostomy had the highest probability of VC. Recipients with biliary reconstruction involving the use of high biliary radicals on the recipient duct had the highest likelihood of developing BC (56% by 1 year) compared with duct-to-duct (42% by 1 year). In conclusion, the varied surgical approaches in the A2ALL centers offer a novel opportunity to compare disparate LDLT approaches. The choice to use higher biliary radicals on the recipient duct for reconstruction was associated with more BC, possibly secondary to devascularization and ischemia. The use of Roux-en-Y biliary reconstruction was associated with VCs (HAT and PVT). These results can be used to guide biliary reconstruction decisions in the setting of anatomic variants and inform further improvements in LDLT reconstructions. Ultimately, this information may contribute to a lower incidence of technical complications after LDLT. Liver Transplantation 23 1519-1530 2017 AASLD.

National assessment of early hospitalization after liver transplantation: Risk factors and association with patient survival

Hospitalization is known to occur frequently in the first 6 months following liver transplantation (LT). Using a novel data linkage between the Scientific Registry of Transplant Recipients and Centers for Medicare and Medicaid Services, our study has 2 objectives: (1) to determine risk factors for "early" hospitalization (ie, within 6 months of LT); and (2) to quantify the importance of hospitalization history in the first 6 months with respect to subsequent patient survival (ie, survival, conditional on surviving 6 months post-LT). The study population consisted of patients aged ≥18 years who underwent deceased donor LT between January 1, 2003 and December 31, 2010, with Medicare as primary or secondary insurance and were discharged alive from the index LT hospitalization (n = 7220). The early hospitalization rate was 2.76 per patient-year and was significantly associated with many recipient factors (eg, recipient age, hepatitis C, diabetes, poor renal function including dialysis, and recipient of transjugular intrahepatic portosystemic shunt procedure before LT), as well as donor race and donation after cardiac death. Conditional on surviving 6 months after LT, the covariate-adjusted death rate increased by 22% for each additional hospitalization occurring in the first 6 months (hazard ratio, 1.22; P < 0.001). In conclusion, several LT recipient factors are significantly associated with early hospitalization. Moreover, a patient's hospitalization profile during follow-up months 0-6 is a very strong predictor of survival thereafter. Efforts and resources should be devoted toward identifying LT recipients at risk for early hospitalization and modifying the actionable risk factors such as hepatitis C, diabetes, and body mass index to improve resource utilization and overall outcomes. Liver Transplantation 23 1143-1152 2017 AASLD.

Reasons for Seeking Clinical Care for Lower Urinary Tract Symptoms: A Mixed Methods Study

PURPOSE

The primary objective of this study was to evaluate reasons for seeking care among men and women with lower urinary tract symptoms.

MATERIALS AND METHODS

Participants were recruited from urology and urogynecology clinics, and the community. The sample was enriched with persons expected to have abnormal or diminished bladder sensations (eg participants with lower back surgery and participants 65 years old or older). Interviews were performed in person beginning with an open-ended assessment of urinary symptoms and associated bother followed by more directed questions, including reasons for seeking or not seeking treatment. We also examined the relationship between symptom frequency and bother using the LUTS (Lower Urinary Tract Symptoms) Tool.

RESULTS

A total of 88 participants, including 38 men and 50 women, with a mean ± SD age of 52.2 ± 14.3 years provided information about urinary symptoms, including a range of quality of life consequences and coping behaviors. They sought treatment mostly because of new, continuing or bothersome symptoms. Factors associated with not seeking treatment included low symptom severity and concerns about the costs vs the benefits of treatment (eg side effects of medication). Symptom frequency and bother were associated with each other across symptoms assessed by the LUTS Tool.

CONCLUSIONS

In this large qualitative study we obtained useful insights into the impact of lower urinary tract symptoms from the perspective of the person with the symptoms. Removing barriers and misconceptions about the treatment of lower urinary tract symptoms may increase the number of people who seek clinical care and improve the clinical course of men and women who experience lower urinary tract symptoms.

National Assessment of Hospitalization Rates for Incident End-Stage Renal Disease After Liver Transplantation

BACKGROUND

We examined the association of incident end-stage renal disease (ESRD) after liver transplantation (LT) and resource utilization using a data linkage between the Scientific Registry of Transplant Recipients and claims data from the Centers for Medicare and Medicaid Services.

METHODS

The study cohort consisted of patients aged ≥18 years who underwent deceased donor LT between January 1, 2003, and December 31, 2010, with Medicare as primary or secondary insurance and were discharged alive from the index LT hospitalization (n = 7019). The association of ESRD and post-LT hospitalization was assessed by sequential stratification, which entailed prognostic score matching of ESRD-free patients to each LT recipient at ESRD onset. The prognostic score was developed from a model of time to hospitalization and included baseline factors and hospitalization history as predictors.

RESULTS

The overall hospitalization rates for LT recipients with and without ESRD were 2.7 and 1.1 per patient-year at risk, respectively. The total number of days hospitalized patient per year was 23 in ESRD and 7 in non-ESRD LT recipients. The adjusted post-LT hospitalization rate was 97% higher after reaching ESRD compared to non-ESRD (hazard ratio, 1.97; P < 0.0001).

CONCLUSIONS

Hospitalization rates increased significantly for LT recipients after ESRD onset. Early risk factor modification efforts targeting patients who are at high ESRD risk may reduce post-LT ESRD incidence and hence decrease morbidity and cost among LT recipients.

The National Living Donor Assistance Center perspective on barriers to the use of federal travel grants for living donors

Recent research has identified important barriers that potential living organ donors face in utilizing travel reimbursement funds from the National Living Donor Assistance Center (NLDAC). In this article, we provide clarification and comment on these potential barriers from the NLDAC program perspective. The goal of financial neutrality for living donors requires further action. We discuss recent developments and further steps that may help achieve this goal and ultimately affect the shortage of donor organs.

Evidence of the Impact of Diet, Fluid Intake, Caffeine, Alcohol and Tobacco on Lower Urinary Tract Symptoms: A Systematic Review

PURPOSE

Diet, fluid intake and caffeine, alcohol and tobacco use may have effects on lower urinary tract symptoms. Constructive changes in these modifiable nonurological factors are suggested to improve lower urinary tract symptoms. To better understand the relationship between nonurological factors and lower urinary tract symptoms, we performed a systematic literature review to examine, grade and summarize reported associations between lower urinary tract symptoms and diet, fluid intake and caffeine, tobacco and alcohol use.

MATERIALS AND METHODS

We performed PubMed® searches for eligible articles providing evidence on associations between 1 or more nonurological factors and lower urinary tract symptoms. A modified Oxford scale was used to grade the evidence.

RESULTS

We reviewed 111 articles addressing diet (28 studies), fluid intake (21) and caffeine (21), alcohol (26) and tobacco use (44). The evidence grade was generally low (6% level 1, 24% level 2, 11% level 3 and 59% level 4). Fluid intake and caffeine use were associated with urinary frequency and urgency in men and women. Modest alcohol use was associated with decreased likelihood of benign prostatic hyperplasia diagnosis and reduced lower urinary tract symptoms in men. Associations between lower urinary tract symptoms and ingestion of certain foods and tobacco were inconsistent.

CONCLUSIONS

Evidence of associations between lower urinary tract symptoms and diet, fluid intake and caffeine, alcohol and tobacco use is sparse and mostly observational. However, there is evidence of associations between increased fluid and caffeine intake and urinary frequency/urgency, and between modest alcohol intake and decreased benign prostatic hyperplasia diagnosis and lower urinary tract symptoms. Given the importance of these nonurological factors in daily life, and their perceived impact on lower urinary tract symptoms, higher quality evidence is needed.

Recurrent primary sclerosing cholangitis in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study: Comparison of risk factors between living and deceased donor recipients

Primary sclerosing cholangitis (PSC) recurs in 15%-25% of patients transplanted for PSC. In the United States, PSC transplant patients are more likely to receive an organ from a living donor (LD) than patients without PSC. Our aims were to (1) compare risk of PSC recurrence in LD versus deceased donor recipients and (2) identify risk factors for PSC recurrence. There were 241 living donor liver transplantations (LDLTs) and 65 deceased donor liver transplantation (DDLT) patients transplanted between 1998 and 2013 enrolled in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study who were evaluated. PSC recurrence risk for LDLT and DDLT recipients was compared using Kaplan-Meier survival curves and log-rank tests. Cox models were used to evaluate PSC risk factors. Overall PSC recurrence probabilities were 8.7% and 22.4% at 5 and 10 years after liver transplantation (LT), respectively. The risk of PSC recurrence was not significantly different for DDLT versus LDLT recipients (P = 0.36). For DDLT versus LDLT recipients, unadjusted 5- and 10-year PSC recurrence was 9.4% versus 9.5% and 36.9% versus 21.1%. Higher laboratory Model for End-Stage Liver Disease (MELD) score at LT, onset of a biliary complication, cholangiocarcinoma, and higher donor age were associated with increased risks of PSC recurrence: for MELD (hazard ratio [HR] = 1.06; 95% confidence interval [CI] 1.02-1.10 per MELD point, P = 0.002); for biliary complication (HR, 2.82; 95% CI, 1.28-6.25; P = 0.01); for cholangiocarcinoma (HR, 3.98; 95% CI, 1.43-11.09; P = 0.008); for donor age (per 5-years donor age; HR, 1.17; 95% CI, 1.02-1.35; P = 0.02). Factors not significantly associated with PSC recurrence included the following: first-degree relative donor (P = 0.11), post-LT cytomegalovirus infection (P = 0.38), and acute rejection (P = 0.22). Risk of recurrent PSC was not significantly different for DDLT and LDLT recipients. Biliary complications, cholangiocarcinoma, MELD, and donor age were significantly associated with risk of PSC recurrence. Liver Transplantation 22 1214-1222 2016 AASLD.

Misclassification Errors in Unsupervised Classification Methods. Comparison Based on the Simulation of Targeted Proteomics Data

Unsupervised classification methods are gaining acceptance in omics studies of complex common diseases, which are often vaguely defined and are likely the collections of disease subtypes. Unsupervised classification based on the molecular signatures identified in omics studies have the potential to reflect molecular mechanisms of the subtypes of the disease and to lead to more targeted and successful interventions for the identified subtypes. Multiple classification algorithms exist but none is ideal for all types of data. Importantly, there are no established methods to estimate sample size in unsupervised classification (unlike power analysis in hypothesis testing). Therefore, we developed a simulation approach allowing comparison of misclassification errors and estimating the required sample size for a given effect size, number, and correlation matrix of the differentially abundant proteins in targeted proteomics studies. All the experiments were performed in silico. The simulated data imitated the expected one from the study of the plasma of patients with lower urinary tract dysfunction with the aptamer proteomics assay Somascan (SomaLogic Inc, Boulder, CO), which targeted 1129 proteins, including 330 involved in inflammation, 180 in stress response, 80 in aging, etc. Three popular clustering methods (hierarchical, k-means, and k-medoids) were compared. K-means clustering performed much better for the simulated data than the other two methods and enabled classification with misclassification error below 5% in the simulated cohort of 100 patients based on the molecular signatures of 40 differentially abundant proteins (effect size 1.5) from among the 1129-protein panel.

Complications and Their Resolution in Recipients of Deceased and Living Donor Liver Transplants: Findings From the A2ALL Cohort Study

The purpose of this study was to explore long-term complications in recipients of deceased donor liver transplant (DDLT) and living donor liver transplant (LDLT) in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). We analyzed 471 DDLTs and 565 LDLTs from 1998 to 2010 that were followed up to 10 years for 36 categories of complications. Probabilities of complications and their resolutions were estimated using the Kaplan-Meier method, and predictors were tested in Cox proportional hazards models. Median follow-up for DDLT and LDLT was 4.19 and 4.80 years, respectively. DDLT recipients were more likely to have hepatocellular carcinoma and higher disease severity, including Model for End-Stage Liver Disease score. Complications occurring with higher probability in LDLT included biliary-related complications and hepatic artery thrombosis. In DDLT, ascites, intra-abdominal bleeding, cardiac complications and pulmonary edema were significantly more probable. Development of chronic kidney disease stage 4 or 5 was less likely in LDLT recipients (hazard ratio [HR] 0.41, p = 0.02). DDLT and LDLT had similar risk of grade 4 complications (HR 0.89, p = 0.60), adjusted for other risk factors. Once a complication occurred, the time to resolution did not differ between LDLT and DDLT. Future efforts should be directed toward reducing the occurrence of complications after liver transplantation.

Serum sodium and survival benefit of liver transplantation

Hyponatremia is associated with elevated wait-list mortality among end-stage liver disease candidates for liver transplantation (LT). However, the effect of low serum sodium on the survival benefit of LT has not been examined. We sought to determine whether pretransplant hyponatremia is associated with an altered LT survival benefit. Data were obtained from the Scientific Registry of Transplant Recipients. The study population consisted of adults (age ≥ 18 years) placed on the waiting list for LT between January 1, 2005 and December 31, 2012 (n = 69,213). The effect of hyponatremia on the survival benefit was assessed via sequential stratification, an extension of Cox regression. Each transplant recipient was matched to appropriate candidates then active on the waiting list with the same Model for End-Stage Liver Disease (MELD) score and in the same donation service area. The focus of the analysis was the interaction between the serum sodium and the MELD score with respect to the survival benefit of LT; this was defined as the covariate-adjusted hazard ratio contrasting post-LT mortality and pre-LT mortality. The LT survival benefit increased significantly with decreasing serum sodium values when the MELD scores were >11. The survival benefit of LT was not affected by serum sodium for patients with MELD scores ≤ 11. In conclusion, the LT survival benefit (or lack thereof) is independent of serum sodium for patients with MELD scores ≤ 11. The increase in the survival benefit with decreasing serum sodium among patients with MELD scores > 11 is consistent with recently approved changes to the allocation system incorporating serum sodium.

Changes in liver and spleen volumes after living liver donation: a report from the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL)

Previous reports have drawn attention to persistently decreased platelet counts among liver donors. We hypothesized an etiologic association between altered platelet counts and postdonation splenomegaly and sought to explore this relationship. This study analyzed de-identified computed tomography/magnetic resonance scans of 388 donors from 9 Adult-to-Adult Living Donor Liver Transplantation Cohort Study centers read at a central computational image analysis laboratory. Resulting liver and spleen volumes were correlated with time-matched clinical laboratory values. Predonation liver volumes varied 2-fold in healthy subjects, even when they were normalized by the body surface area (BSA; range = 522-1887 cc/m(2) , n = 346). At month 3 (M3), postdonation liver volumes were, on average, 79% of predonation volumes [interquartile range (IQR) = 73%-86%, n = 165] and approached 88% at year 1 (Y1; IQR = 80%-93%, n = 75). The mean spleen volume before donation was 245 cc (n = 346). Spleen volumes greater than 100% of the predonation volume occurred in 92% of donors at M3 (n = 165) and in 88% at Y1 after donation (n = 75). We sought to develop a standard spleen volume (SSV) model to predict normal spleen volumes in donors before donation and found that decreased platelet counts, a younger age, a higher predonation liver volume, higher hemoglobin levels, and a higher BSA predicted a larger spleen volume (n = 344, R(2)  = 0.52). When this was applied to postdonation values, some large volumes were underpredicted by the SSV model. Models developed on the basis of the reduced sample of postdonation volumes yielded smaller underpredictions. These findings confirm previous observations of thrombocytopenia being associated with splenomegaly after donation. The results of the SSV model suggest that the biology of this phenomenon is complex. This merits further long-term mechanistic studies of liver donors with an investigation of the role of other factors such as thrombopoietin and exposure to viral infections to better understand the evolution of the spleen volume after liver donation.

Long-term quality of life after liver donation in the adult to adult living donor liver transplantation cohort study (A2ALL)

BACKGROUND & AIMS

There are few long-term studies of the health-related quality of life (HRQOL) in living liver donors. This study aimed to characterize donor HRQOL in the Adult to Adult Living Donor Liver Transplantation Study (A2ALL) up to 11 years post-donation.

METHODS

Between 2004 and 2013, HRQOL was assessed at evaluation, at 3 months, and yearly post-donation in prevalent liver donors using the short-form survey (SF-36), which provides a physical (PCS) and a mental component summary (MCS).

RESULTS

Of the 458 donors enrolled in A2ALL, 374 (82%) had SF-36 data. Mean age at evaluation was 38 (range 18-63), 47% were male, 93% white, and 43% had a bachelor's degree or higher. MCS and PCS means were above the US population at all time points. However, at every time point there were some donors who reported poor scores (>1/2 standard deviation below the age and sex adjusted mean) (PCS: 5.3-26.8%,

MCS

10.0-25.0%). Predictors of poor PCS and MCS scores included recipient's death within the two years prior to the survey and education less than a bachelor's degree; poor PCS scores were also predicted by time since donation, Hispanic ethnicity, and at the 3-month post-donation time point.

CONCLUSIONS

In summary, most living donors maintain above average HRQOL up to 11 years prospectively, supporting the notion that living donation does not negatively affect HRQOL. However, targeted support for donors at risk for poor HRQOL may improve overall HRQOL outcomes for living liver donors.

Outcomes of liver transplantation for porto-pulmonary hypertension in model for end-stage liver disease era

Porto-pulmonary hypertension (POPH), once considered an absolute contraindication for liver transplantation (LT), has become a more accepted indication because of the evolution of treatment with prostacyclin analogues, phosphodiesterase inhibitors and endothelin receptor antagonists. An exception model for end stage liver disease (MELD) score of 22 is assigned to candidates with documentation of effective treatment. We examined the post-transplant outcomes of patients who received LT for POPH with exception.

METHODS

Scientific Registry of Transplant Recipients data on 34,318 adult (≥ 18 years) deceased donor LT recipients transplanted between March 1, 2002 and August 31, 2010 were reviewed. The diagnosis of POPH was ascertained from MELD exception forms. Patients were followed from the time of transplant until the earlier occurrence of death or end of the follow-up period. Cox regression was used to evaluate the predictors of post-LT mortality and graft failure.

RESULTS

During the study period, 34,318 patients received deceased donor LT. Seventy eight out of 34,318 patients were transplanted for POPH with MELD exception. The 1-year adjusted risks of patient death and graft failure for patients transplanted under exception rules for POPH were significantly higher than with POPH adult recipients who did not receive exception points (death:hazard ratio [HR] = 2.25, p = 0.005 and graft failure HR = 1.96, p = 0.012).

CONCLUSIONS

This study of national data suggests that treated POPH continues to be associated with inferior early post-transplant outcomes.

Development of the National Living Donor Assistance Center: reducing financial disincentives to living organ donation

Over the years, the transplant community has worked to advance the care of living organ donors; however, barriers remain, including the nonmedical expenses incurred by living donors. A new center, funded by a grant from the Health Resources and Services Administration (HRSA), was established to operate a nationwide system to remove these financial disincentives. The HRSA grant was awarded to an academic institution and the daily operations are managed by a transplant professional society. Expenses are reimbursed prospectively for financially needy living donors. Combining the legislative authority and economic resources of the federal government, the research experience of an academic institution, and the management know-how of a professional society has proven to be successful. To date, the center has received 3918 applications submitted by 199 different transplant centers and receives about 80 applications per month. On average, a donor spends $2767 for their travel expenses to the transplant center. Of the 3918 applications that have been submitted, 1941 of those applicants (50%) have completed their donor surgery.

Disparities in liver transplantation: the association between donor quality and recipient race/ethnicity and sex

BACKGROUND

We aimed to examine the association between recipient race/ethnicity and sex, donor liver quality, and liver transplant graft survival.

METHODS

Adult non-status 1 liver recipients transplanted between March 1, 2002, and December 31, 2008, were identified using Scientific Registry of Transplant Recipients data. The factors of interest were recipient race/ethnicity and sex. Donor risk index (DRI) was used as a donor quality measure. Logistic regression was used to assess the association between race/ethnicity and sex in relation to the transplantation of low-quality (high DRI) or high-quality (low DRI) livers. Cox regression was used to assess the association between race/ethnicity and sex and liver graft failure risk, accounting for DRI.

RESULTS

Hispanics were 21% more likely to receive low-quality grafts compared to whites (odds ratio [OR]=1.21, P=0.002). Women had greater odds of receiving a low-quality graft compared to men (OR=1.24, P<0.0001). Despite adjustment for donor quality, African American recipients still had higher graft failure rates compared to whites (hazard ratio [HR]=1.28, P<0.001). Hispanics (HR=0.89, P=0.023) had significantly lower graft failure rates compared to whites despite higher odds of receiving a higher DRI graft. Using an interaction model of DRI and race/ethnicity, we found that the impact of DRI on graft failure rates was significantly reduced for African Americans compared to whites (P=0.02).

CONCLUSIONS

This study shows that while liver graft quality differed significantly by recipient race/ethnicity and sex, donor selection practices do not seem to be the dominant factor responsible for worse liver transplant outcomes for minority recipients.

Patient-specific prediction of ESRD after liver transplantation

Incident ESRD after liver transplantation (LT) is associated with high post-transplant mortality. We constructed and validated a continuous renal risk index (RRI) to predict post-LT ESRD. Data for 43,514 adult recipients of deceased donor LT alone (February 28, 2002 to December 31, 2010) were linked from the Scientific Registry of Transplant Recipients and the Centers for Medicare and Medicaid Services ESRD Program. An adjusted Cox regression model of time to post-LT ESRD was fitted, and the resulting equation was used to calculate an RRI for each LT recipient. The RRI included 14 recipient factors: age, African-American race, hepatitis C, cholestatic disease, body mass index ≥ 35, pre-LT diabetes, ln creatinine for recipients not on dialysis, ln albumin, ln bilirubin, serum sodium<134 mEq/L, status-1, previous LT, transjugular intrahepatic portosystemic shunt, and acute dialysis at LT. This RRI was validated and had a C statistic of 0.76 (95% confidence interval, 0.75 to 0.78). Higher RRI associated significantly with higher 5-year cumulative incidence of ESRD and post-transplant mortality. In conclusion, the RRI constructed in this study quantifies the risk of post-LT ESRD and is applicable to all LT alone recipients. This new validated measure may serve as an important prognostic tool in ameliorating post-LT ESRD risk and improve survival by informing post-LT patient management strategies.

Systematic bias in surgeons' predictions of the donor-specific risk of liver transplant graft failure

The decision to accept or decline a liver allograft for a patient on the transplant waiting list is complex. We hypothesized that surgeons are not accurate at predicting donor-specific risks. Surgeon members of the American Society of Transplant Surgeons were invited to complete a survey in which they predicted the 3-year risk of graft failure for a 53-year-old man with alcoholic cirrhosis and a Model for End-Stage Liver Disease score of 21 with a liver from (1) a 30-year-old local donor with traumatic brain death or (2) a 64-year-old regional donor with brain death from a stroke. Complete responses were obtained from 201 surgeons, whose self-reported case volume represents the majority of liver transplants in the United States. The surgeon-predicted 3-year risk of graft failure varied widely (more than 10-fold). In scenario 1, 90% of the respondents provided lower estimates of the graft failure risk than the literature-derived estimate of 21% (P < 0.001). In scenario 2, 96% of the responses were lower than the literature-derived estimate of 40% (P < 0.001). In conclusion, transplant surgeons vary widely in their predictions of the donor-specific risk of graft failure, and they demonstrate a systematic bias toward inaccurately low estimates of graft failure, particularly for higher risk organs.

Development, management, and resolution of biliary complications after living and deceased donor liver transplantation: a report from the adult-to-adult living donor liver transplantation cohort study consortium

Adult recipients of living donor liver transplantation (LDLT) have a higher incidence of biliary complications than recipients of deceased donor liver transplantation (DDLT). Our objective was to define the intensity of the interventions and the time to resolution after the diagnosis of biliary complications after liver transplantation. We analyzed the management and resolution of posttransplant biliary complications and investigated the comparative effectiveness of interventions in LDLT and DDLT recipients. For the analysis of biliary complications (leaks or strictures), we used a retrospective cohort of patients who underwent liver transplantation at 8 centers between 1998 and 2006 (median follow-up from onset=4.7 years). The numbers, procedure types, and times to resolution were compared for LDLT and DDLT recipients. Posttransplant biliary complications occurred in 47 of the 189 DDLT recipients (25%) and in 141 of the 356 LDLT recipients (40%). Biliary leaks constituted 38% of the post-DDLT biliary complications (n=18) and 65% of the post-LDLT biliary complications (n=91). The median times to first biliary complications were similar for DDLT and LDLT (11 versus 14 days for leaks, P=0.63; 69 versus 107 days for strictures, P=0.34). Overall, 1225 diagnostic and therapeutic procedures, including reoperation and retransplantation, were performed (6.5±5.4 per recipient; 5.5±3.6 for DDLT versus 6.8±5.8 for LDLT, P=0.52). The median number of months to the resolution of a biliary complication (i.e., a tube-, stent-, and drain-free status) did not significantly differ between the DDLT and LDLT groups for leaks (2.3 versus 1.3 months, P=0.29) or strictures (4.9 versus 2.3 months, P=0.61). Although the incidence of biliary complications is higher after LDLT versus DDLT, the treatment requirements and the time to resolution after the development of a biliary complication are similar for LDLT and DDLT recipients.

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.

Demographic, metabolic, and blood pressure characteristics of living kidney donors spanning five decades

While cautious criteria for selection of living kidney donors are credited for favorable outcomes, recent practice changes may include acceptance of less than ideal donors. To characterize trends in donor acceptance, the Renal and Lung Living Donors Evaluation (RELIVE) Study evaluated 8,951 kidney donors who donated between 1963 and 2007 at three major U.S. transplant centers. Over the study interval, there was an increase in the percentage of donors >40 years old from 38% to 51%; donors >60 years varied between 1% and 4%. The proportion of donors with obesity increased from 8% to 26% and with glucose intolerance from 9% to 25%. The percentage of hypertensive donors was consistent (5-8%). Accepted donors ≥60 years old were more likely to have obesity, glucose intolerance, and/or hypertension compared to younger donors (p<0.0001). Our results demonstrate important trends in acceptance of older and more obese donors. The fraction of older donors accepted with glucose intolerance or hypertension remains small and for the majority includes mild elevations in glucose or blood pressure that were previously classified as within normal limits.

Factors that affect deceased donor liver transplantation rates in the United States in addition to the Model for End-stage Liver Disease score

Under an ideal implementation of Model for End-Stage Liver Disease (MELD)-based liver allocation, the only factors that would predict deceased donor liver transplantation (DDLT) rates would be the MELD score, blood type, and donation service area (DSA). We aimed to determine whether additional factors are associated with DDLT rates in actual practice. Data from the Scientific Registry of Transplant Recipients for all adult candidates wait-listed between March 1, 2002 and December 31, 2008 (n = 57,503) were analyzed. Status 1 candidates were excluded. Cox regression was used to model covariate-adjusted DDLT rates, which were stratified by the DSA, blood type, liver-intestine policy, and allocation MELD score. Inactive time on the wait list was not modeled, so the computed DDLT hazard ratios (HRs) were interpreted as active wait-list candidates. Many factors, including the candidate's age, sex, diagnosis, hospitalization status, and height, prior DDLT, and combined listing for liver-kidney or liver-intestine transplantation, were significantly associated with DDLT rates. Factors associated with significantly lower covariate-adjusted DDLT rates were a higher serum creatinine level (HR = 0.92, P < 0.001), a higher bilirubin level (HR = 0.99, P = 0.001), and the receipt of dialysis (HR = 0.83, P < 0.001). Mild ascites (HR = 1.15, P < 0.001) and hepatic encephalopathy (grade 1 or 2, HR = 1.05, P = 0.02; grade 3 or 4, HR = 1.10, P = 0.01) were associated with significantly higher adjusted DDLT rates. In conclusion, adjusted DDLT rates for actively listed candidates are affected by many factors aside from those integral to the allocation system; these factors include the components of the MELD score itself as well as candidate factors that were considered but were deliberately omitted from the MELD score in order to keep it objective. These results raise the question whether additional candidate characteristics should be explicitly incorporated into the prioritization of wait-list candidates because such factors are already systematically affecting DDLT rates under the current allocation system.

Predictors of liver donation without kidney recovery in a cohort of expanded criteria donors: identifying opportunities to improve expanded criteria donor kidney utilization

To maximize deceased donation, it is necessary to facilitate organ recovery from expanded criteria donors (ECDs). Utilization of donors meeting the kidney definition for ECDs increases access to kidney transplantation and reduces waiting times; however, ECDs often do not proceed to kidney recovery. Based on a prospective study of three Organ Procurement Organizations in the United States, we describe the characteristics of donors meeting the Organ Procurement and Transplant Network (OPTN) ECD kidney definition (donor age 60+ or donor age 50-60 years with two of the following: final serum creatinine > 1.5 mg/dL, history of hypertension, or death from cerebral vascular accident) who donated a liver without kidney recovery. ECDs with organs recovered between February 2003 and September 2005 by New England Organ Bank, Gift of Life Michigan, and LifeChoice Donor Services were studied (n = 324). All donors were declared dead by neurological criteria. Data on a wide range of donor characteristics were collected, including donor demographics, medical history, cause of death, donor status during hospitalization, serological status, and donor kidney quality. Logistic regression models were used to identify donor characteristics predictive of liver-alone donation. Seventy-four of the 324 donors fulfilling the ECD definition for kidneys donated a liver alone (23%). History of diabetes, final serum creatinine > 1.5 mg/dL, age 70+, and presence of proteinuria were associated with liver-alone donation in univariate models. On multivariate analysis, only final serum creatinine > 1.5 mg/dL and age 70+ were independently predictive of liver donation alone. Older age and elevated serum creatinine may be perceived as stronger contraindications to kidney donation than the remaining elements of the ECD definition. It is likely that at least a proportion of these liver-alone donors represent missed opportunities for kidney transplantation.

Utilization of kidneys with similar kidney donor risk index values from standard versus expanded criteria donors

With the shortage of standard criteria donor (SCD) kidneys, efficient expanded criteria donor (ECD) kidney utilization has become more vital. We investigated the effects of the ECD label on kidney recovery, utilization and outcomes. Using data from the Scientific Registry of Transplant Recipients from November 2002 to May 2010, we determined recovery and transplant rates, and modeled discard risk, for kidneys within a range of kidney donor risk index (KDRI) 1.4-2.1 that included both SCD and ECD kidneys. To further compare similar quality kidneys, these kidneys were again divided into three KDRI intervals. Overall, ECD kidneys had higher recovery rates, but lower transplant rates. However, within each KDRI interval, SCD and ECD kidneys were transplanted at similar rates. Overall, there was increased risk for discard for biopsied kidneys. SCD kidneys in the lower two KDRI intervals had the highest risk of discard if biopsied. Pumped kidneys had a lower risk of discard, which was modulated by KDRI for SCD kidneys but not ECD kidneys. Although overall ECD graft survival was worse than SCD, there were no differences within individual KDRI intervals. Thus, ECD designation adversely affects neither utilization nor outcomes beyond that predicted by KDRI.

Comparison of the long-term outcomes of kidney transplantation: USA versus Spain

BACKGROUND

The long-term outcomes of kidney transplantation are suboptimal because many patients lose their allografts or experience premature death. Cross-country comparisons of long-term outcomes of kidney transplantation may provide insight into factors contributing to premature graft failure and death. We evaluated the rates of late graft failure and death among US and Spanish kidney recipients.

METHODS

This is a cohort study of US (n = 9609) and Spanish (n = 3808) patients who received a deceased donor kidney transplant in 1990, 1994, 1998 or 2002 and had a functioning allograft 1 year after transplantation with follow-up through September 2006. Ten-year overall and death-censored graft survival and 10-year overall recipient survival and death with graft function (DWGF) were estimated with multivariate Cox models.

RESULTS

Among recipients alive with graft function 1 year after transplant, the 10-year graft survival was 71.3% for Spanish and 53.4% for US recipients (P < 0.001). The 10-year, death-censored graft survival was 75.6 and 76.0% for Spanish and US recipients, respectively (P = 0.73). The 10-year recipient survival was 86.2% for Spanish and 67.4% for US recipients (P < 0.001). In recipients with diabetes as the cause of ESRD, the adjusted DWGF rates at 10 years were 23.9 and 53.8 per 1000 person-years for Spanish and US recipients, respectively (P < 0.001). Among recipients whose cause of ESRD was not diabetes mellitus, the adjusted 10-year DWGF rates were 11.0 and 25.4 per 1000 person-years for Spanish and US recipients, respectively.

CONCLUSIONS

US kidney transplant recipients had more than twice the long-term hazard of DWGF compared with Spanish kidney transplant recipients and similar levels of death-censored graft function. Pre-transplant medical care, comorbidities, such as cardiovascular disease, and their management in each country's health system are possible explanations for the differences between the two countries.

Incidence and risk factors of hepatocellular carcinoma recurrence after liver transplantation in the MELD era

BACKGROUND AND AIMS

Deceased donor liver transplantation (DDLT) rates for candidates with hepatocellular carcinoma (HCC) have significantly increased in the MELD era because of the extra priority given to these candidates. We examined the incidence and pre-DDLT radiological and donor factors associated with post-DDLT HCC recurrence in the MELD era.

METHODS

Outcomes of HCC candidates aged ≥18 years that underwent DDLT between 2/28/02 and 6/30/08 (n = 94) were reviewed. The primary outcome was biopsy-proven post-LT HCC recurrence at any site. Kaplan-Meier analysis was used to calculate the cumulative incidence and Cox regression was used to identify the predictors of post-LT HCC recurrence.

RESULTS

The median age of the 94 candidates who met the study criteria was 54 years, 64% had hepatitis C, median lab MELD was 13, and median pre-LT AFP was 47 ng/dl. Based upon pre-DDLT imaging, 94% candidates met the Milan criteria. The median waiting time to transplant was 47 days and 27% received pre-DDLT loco-regional therapy. Seventeen (18%) developed HCC recurrence after 2.1 median years with a cumulative incidence of 6.8, 12, and 19% at 1, 2, and 3 years post-DDLT. The pre-DDLT number of lesions (p = 0.015), largest lesion diameter (p = 0.008), and higher donor age (p = 0.002) were the significant predictors of HCC recurrence after adjusting for pre-LT loco-regional therapy and waiting time. Post-LT HCC recurrence (p < 0.0001) and higher donor age (p = 0.029) were associated with lower post-LT survival.

CONCLUSIONS

Post-LT HCC recurrence is higher in our MELD era cohort than the reported rate of 8% at 4 years in Mazzaferro et al.'s study. The risk of HCC recurrence was significantly associated with the number of lesions and size of the largest lesion at the time of DDLT as well as with older donor age. Risk stratification using a predictive model for post-LT HCC recurrence based on pre-LT imaging and donor factors may help guide candidate selection and tailoring of HCC surveillance strategies after LT.

End-stage liver disease candidates at the highest model for end-stage liver disease scores have higher wait-list mortality than status-1A candidates

Candidates with fulminant hepatic failure (Status-1A) receive the highest priority for liver transplantation (LT) in the United States. However, no studies have compared wait-list mortality risk among end-stage liver disease (ESLD) candidates with high Model for End-Stage Liver Disease (MELD) scores to those listed as Status-1A. We aimed to determine if there are MELD scores for ESLD candidates at which their wait-list mortality risk is higher than that of Status-1A, and to identify the factors predicting wait-list mortality among those who are Status-1A. Data were obtained from the Scientific Registry of Transplant Recipients for adult LT candidates (n = 52,459) listed between September 1, 2001, and December 31, 2007. Candidates listed for repeat LT as Status-1 A were excluded. Starting from the date of wait listing, candidates were followed for 14 days or until the earliest occurrence of death, transplant, or granting of an exception MELD score. ESLD candidates were categorized by MELD score, with a separate category for those with calculated MELD > 40. We compared wait-list mortality between each MELD category and Status-1A (reference) using time-dependent Cox regression. ESLD candidates with MELD > 40 had almost twice the wait-list mortality risk of Status-1A candidates, with a covariate-adjusted hazard ratio of HR = 1.96 (P = 0.004). There was no difference in wait-list mortality risk for candidates with MELD 36-40 and Status-1A, whereas candidates with MELD < 36 had significantly lower mortality risk than Status-1A candidates. MELD score did not significantly predict wait-list mortality among Status-1A candidates (P = 0.18). Among Status-1A candidates with acetaminophen toxicity, MELD was a significant predictor of wait-list mortality (P < 0.0009). Posttransplant survival was similar for Status-1A and ESLD candidates with MELD > 20 (P = 0.6).

CONCLUSION

Candidates with MELD > 40 have significantly higher wait-list mortality and similar posttransplant survival as candidates who are Status-1A, and therefore, should be assigned higher priority than Status-1A for allocation. Because ESLD candidates with MELD 36-40 and Status-1A have similar wait-list mortality risk and posttransplant survival, these candidates should be assigned similar rather than sequential priority for deceased donor LT.

Impact of MELD-based allocation on end-stage renal disease after liver transplantation

The proportion of patients undergoing liver transplantation (LT), with concomitant renal dysfunction, markedly increased after allocation by the model for end-stage liver disease (MELD) score was introduced. We examined the incidence of subsequent post-LT end-stage renal disease (ESRD) before and after the policy was implemented. Data on all adult deceased donor LT recipients between April 27, 1995 and December 31, 2008 (n = 59 242), from the Scientific Registry of Transplant Recipients, were linked with Centers for Medicare & Medicaid Services' ESRD data. Cox regression was used to (i) compare pre-MELD and MELD eras with respect to post-LT ESRD incidence, (ii) determine the risk factors for post-LT ESRD and (iii) quantify the association between ESRD incidence and mortality. Crude rates of post-LT ESRD were 12.8 and 14.5 per 1000 patient-years in the pre-MELD and MELD eras, respectively. Covariate-adjusted post-LT ESRD risk was higher in the MELD era (hazard ratio [HR]= 1.15; p = 0.0049). African American race, hepatitis C, pre-LT diabetes, higher creatinine, lower albumin, lower bilirubin and sodium >141 mmol/L at LT were also significant predictors of post-LT ESRD. Post-LT ESRD was associated with higher post-LT mortality (HR = 3.32; p < 0.0001). The risk of post-LT ESRD, a strong predictor of post-LT mortality, is 15% higher in the MELD era. This study identified potentially modifiable risk factors of post-LT ESRD. Early intervention and modification of these risk factors may reduce the burden of post-LT ESRD.

Liver transplant recipient survival benefit with living donation in the model for endstage liver disease allocation era

Receipt of a living donor liver transplant (LDLT) has been associated with improved survival compared with waiting for a deceased donor liver transplant (DDLT). However, the survival benefit of liver transplant has been questioned for candidates with Model for Endstage Liver Disease (MELD) scores <15, and the survival advantage of LDLT has not been demonstrated during the MELD allocation era, especially for low MELD patients. Transplant candidates enrolled in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study after February 28, 2002 were followed for a median of 4.6 years. Starting at the time of presentation of the first potential living donor, mortality for LDLT recipients was compared to mortality for patients who remained on the waiting list or received DDLT (no LDLT group) according to categories of MELD score (<15 or ≥ 15) and diagnosis of hepatocellular carcinoma (HCC). Of 868 potential LDLT recipients (453 with MELD <15; 415 with MELD ≥ 15 at entry), 712 underwent transplantation (406 LDLT; 306 DDLT), 83 died without transplant, and 73 were alive without transplant at last follow-up. Overall, LDLT recipients had 56% lower mortality (hazard ratio [HR] = 0.44, 95% confidence interval [CI] 0.32-0.60; P < 0.0001). Among candidates without HCC, mortality benefit was seen both with MELD <15 (HR = 0.39; P = 0.0003) and MELD ≥ 15 (HR = 0.42; P = 0.0006). Among candidates with HCC, a benefit of LDLT was not seen for MELD <15 (HR = 0.82, P = 0.65) but was seen for MELD ≥ 15 (HR = 0.29, P = 0.043).

CONCLUSION

Across the range of MELD scores, patients without HCC derived a significant survival benefit when undergoing LDLT rather than waiting for DDLT in the MELD liver allocation era. Low MELD candidates with HCC may not benefit from LDLT.

Sex-based disparities in liver transplant rates in the United States

We sought to characterize sex-based differences in access to deceased donor liver transplantation. Scientific Registry of Transplant Recipients data were used to analyze n = 78 998 adult candidates listed before (8/1997-2/2002) or after (2/2002-2/2007) implementation of Model for End-Stage Liver Disease (MELD)-based liver allocation. The primary outcome was deceased donor liver transplantation. Cox regression was used to estimate covariate-adjusted differences in transplant rates by sex. Females represented 38% of listed patients in the pre-MELD era and 35% in the MELD era. Females had significantly lower covariate-adjusted transplant rates in the pre-MELD era (by 9%; p < 0.0001) and in the MELD era (by 14%; p < 0.0001). In the MELD era, the disparity in transplant rate for females increased as waiting list mortality risk increased, particularly for MELD scores ≥15. Substantial geographic variation in sex-based differences in transplant rates was observed. Some areas of the United States had more than a 30% lower covariate-adjusted transplant rate for females compared to males in the MELD era. In conclusion, the disparity in liver transplant rates between females and males has increased in the MELD era. It is especially troubling that the disparity is magnified among patients with high MELD scores and in certain regions of the United States.