Projected 20-Year and 30-Year Survival Rates for Pediatric Liver Transplant Recipients (U.S.)

A recent study (MG Bowring et al. JPGN 2020; 70: 356-63) provides data on pediatric liver transplantation (LT) survival rates and projected survival rates.

This retrospective cohort study included 13,442 first-time pediatric (<18) LT recipients from 1987-2018.

Key findings:

  • Projected 20-year survival rate for pediatric LT from 2007-18: 84.0%
  • Prior 20-year survival rates: 72.8% (1997-2006 cohort) and 63.6% (1987-1996 cohort)
  • Projected 30-year survival rates for pediatric LT from 2007-18: 80.1%
  • Prior 30-year survival rates: 68.6% (1997-2006 cohort) and 57.5% (1987-1996 cohort)
  • Projected outcomes with split LT (28% of 2007-2018 cohort) are similar to outcomes with whole LT

My take: While projections can overestimate and underestimate survival rates, the clear trend has been a remarkable improvement in long-term outcomes.  This published data can provide current expectations when counseling families, though with ongoing improvements in management/development of tolerance, the hope is for even better outcomes.

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View from the top of Blood Mountain, Ga

What to Expect After Pediatric Liver Transplantation: Cognitive Function and Quality of Life

A recent study (D Ohnemus et al. Liver Transplantation 2020; 26: 45-56, editorial 9-11) examined health-related quality of life (HRQOL) and cognitive functioning approximately 15 years after liver transplantation (LT).

Study details:

Median age 16 years.  Original group was a SPLIT research cohort recruited from 20 centers and then tested at multiple time points; for this study, 8 sites of the original 20 were included.  It is noted that patients with serious neurologic injury were excluded. Among an initial group of 108, there were 79 available for potential enrollment.  In this group, 65 parent surveys were completed and 61 child surveys.

Key findings:

  • For cognitive and school functioning, 60% and 51% of parents reported “poor” functioning, respectively (>1 SD below the health mean).  41% of children rated their cognitive function as poor.
  • Adolescents’ self-reported overall HRQOL was similar to that of healthy children; in contrast, parents rated their teenage children as having significantly worse HRQOL than healthy children in all domains.
  • The cognitive score in the poor functioning group at the latest time point was lower than at first time point measurement (ages 5-6 years and at least 2 years after LT), “suggesting that difficulties intensified in adolescence for those who have problems in early childhood.”
  • Almost half had received special educational services.

The editorial notes that the PedsQL Cognitive Functioning Scale scores used by the investigators were considered subjective.  “The more objective PedsPCF scores fell within the normal range.”

My take: This report indicates that a majority of children are likely to have some cognitive deficits and many are likely to have reduced HRQOL following liver transplantation; in addition, if these problems are detected at a younger age, they are likely to persist.

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Mural on Atlanta’s Beltway

Outcomes of Liver Transplantation in Small Infants

A recent study (H Yamamoto et al. Liver Transplantation 2019; 25: 1561-70) provides data on the outcomes of infants who underwent liver transplantation (LT) in the United Kingdom (King’s College Hospital).

A total of 64 infants underwent LT (1989-2014) at a single institution. The authors compared “extra-small” (XS) infants in the first 3 months of life to “small” (S) who were 3-6 months of age.

Key findings:

  • Acute liver failure was the main indication for LT in the XS group (n=31, 84%) compared to the S group (7, 26%)
  • Hepatic artery thrombosis and portal vein thrombosis were similar in both groups: 5.4% and 10.8% in the XS and 7.4% and 11.1% in the S group
  • Bilary stricture and leakage were similar: 5.4% and 2.7% in the XS and 3.7% and 3.7% in the S group
  • 1-, 5-, and 10-year survivals were 70.3%, 70.3% and 70.3% in the XS group and 92.6%, 88.9%, and 88.9% in the S group (not statistically significant)

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Quebec City, Frontenac Hotel and Boardwalk (early in the day)

Need Liver, Will Travel (2019)

A recent study (AJ Kwong et al Clin Gastroenterol Hepatol 2019; 17: 2347-55) quantifies the potential advantage of moving to receive a liver transplant. This had been discussed in 2016 blog post as well (Need Liver, Will Travel)

During the study period (2004-2016), there were 104,914 waitlist registrations.

Key findings:

  • 60.985 patients received a liver transplant during the study period
  • 2930  (2.8%) pursued listing at a distant center
  • Distant listing was associated with a 22% reductinon in the risk of death within 1 year

My take: this study highlights socioeconomic disparity in acquiring a liver transplant along with potential geographic disparities.

Related article:

“Transplantation Traffic –Geography as Destiny for Transplant Candidates” NEJM 2014; 271: 2450-52.  Describes ongoing geographic inequality in organ distribution and obstacles to improving allocation.

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Botanical Garden,, Chicago

Sad Truth: Job Security in Hepatology

A recent study (ND Parikh et al. Hepatology 2019; 70: 487-95, and associated editorial JA Marrero. 459-61) provide a forecast of increasing liver disease and liver disease severity, driven mainly by fatty liver disease and obesity.

Key findings:

  • Nonalcoholic fatty liver disease (NAFLD) related additions to the liver transplant waitlist expanded from 391 in 2000 to 1605 in 2014.  This corresponded to an overall increase in obesity of 44.1% during that time period.
  • NAFLD-related wait-list additions were predicted by the prevalence of obesity 9 years prior.
  • The authors anticipate that obesity population will increase to over 92 million adults by 2025.
  • The authors project that NAFLD-related wait-list additions will increase to 2104 by 2030, a 55% increase

Because the decrease in complications related to new treatments for Hepatitis C is not expected “until well into the next decade,” the burden of chronic liver disease will continue to rise.

The editorial notes that overall graft survival rates for obese patients with BMI less than 40 do not appear different than those of lean individuals.  Those with BMI >40 had reduced 5-year graft and survival rates.  Also, obese patients have higher morbidities, even in those without reduced survival.

My take: This study identifies a marked increase in end-stage liver disease in the growing population of obese patients.

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How Does USA Compare to Other Countries in Pediatric Liver Transplantation

A recent study (B Fischler et al. JPGN 2019; 68: 700-05) compared the similarities and differences in allocation experience among 15 countries based on a survey completed by a representative hepatologist in each country.

Key findings:

  • The number of liver transplants was 4 to 9 million inhabitants younger than 18 years for 13 of the 15 respondents. USA had the 5th highest rate at ~7 per million inhabitants (Figure 2)
  • USA had the 3rd highest donation rate per million inhabitants, ~26 per million.  Spain had highest rate at 35 per million.  This is partly related to Spain allocating all nonugent pediatric cadaveric donors to pediatric candidates.
  • USA had the 3rd lowest rate of living-related liver transplantation percentage in children < 2 yrs, approximately 10%.  Both Turkey and Poland had rates near 90%.
  • USA had one of the lowest rates of %split liver transplantations for children <2 yrs, less than 10%. Italy, Netherlands, and New Zealand had rates near 90%.
  • USA had the 4th highest waitlist mortality for children <2 yrs, approximately 11%

My take: This study indicates that the rate of split liver transplants and living related liver transplants are much lower in USA than in other countries.  This is likely to reduce donor pool and contribute to increased waiting list mortality.

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Liver Shorts: May 2019

ED Bethea et al. Clin Gastroenterol Hepatol 2019; 17: 739-47. Using a Markov-based mathematical model, the authors “found transplanting HCV-positive livers into HCV-negative patients with preemptive DAA therapy to a cost-effective strategy that could improve health outcomes.”

A Villanueva. NEJM 2019; 1450-62. This is a succinct review of hepatocellular carcinoma (HCC). Some points:

  • More than 1 million patients will die from liver cancer in 2030.
  • The rate of death from liver cancer increased 43% from 2000 to 2016,.  The 5-year survival rate is grim at only 18%.  Only pancreatic cancer is more lethal.
  • HCC is rare among patients without preexisting liver disease.  Cirrhosis is the main risk factor, though hepatitis B has direct oncologic effects even in the absence of cirrhosis.
  • The authors note that cancer surveillance has no “high-quality randomized controlled trials.” However, this may be due to difficulties with enrollment. In one study, 99%of patients declined to assume the risk of being randomly assigned to the nonsurveillance group. Nonetheless, mathematical models, and lower quality studies all show survival benefits of surveillance.

Related blog post:

  • Liver Shorts April 2019 Obesity/NAFLD and alcoholic liver disease are driving an increase in HCC and liver cancer mortality

Best Predictor for Mortality from Biliary Atresia Liver Transplantation Candidates –Cardiomyopathy?

Briefly noted: A recent study (NM Gorgis et al. Hepatology 2019; 69: 1206-18, editorial 940-2 by Elizabeth Rand) indicates that cirrhotic cardiomyopathy (CCM) is very important factor for survival for biliary atresia (BA) patients requiring liver transplantation.

CCM was defined based on two-dimensional echocardiographic criteria: LV mass index ≥95 g/meter-squared or relative wall LV thickness of LV ≥0.42.

Key points:

  • Overall, 11 of 69 patients died, 4 while awaiting liver transplantation and 7 following transplantation.
  • 34 of 69 BA patients in this cohort had BA-CCM
  • All 11 who died had BA-CCM compared with no deaths in the 35 patients without CCM.

My take: Severe BA-CCM needs to be examined further; if severe, it may merit changing allocation policy.

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Joshua Tree National Park

Teaching an Old Liver New Tricks

A recent retrospective study (JD de Boer et al. Liver Transplantation 2019; 25: 260-74) helps address the question of whether/when a geriatric liver is too old for donation.

The authors culled data from 2000-2015 from 17,811 first liver transplantations performed in the Eurotranplant region.

Key findings:

  • 2394 (13%) transplants were performed with livers ≥70 years old
  • Graft survival was reduced from donors with a history of diabetes (HR 1.3) and in recipients with hepatitis C virus (HCV) antibody (HR 1.5)
  • “Although donor age is associated with a linearly increasing risk of graft loss between 25 and 80 years old, no differences in graft survival could be observed when “preferred” recipients were transplanted” with older grafts (HR 1.1).
  • Preferred recipients: 1. HCV-Ab neg, 2. Recipient >45 years old, 3. BMI <35 kg/m2, 4. cold ischemia time < 8 hours. 26% of recipients were considered “preferred” recipients
  • Utilization of livers from donors ≥70 years old increased from 42% (2000-2003) to 76% (2013-2015).
  • The median donor age increased from 42 to 55 years old from 2000 to 2015.
  • The oldest transplanted liver was 98 years old!

The overall Kaplan-Meier survival curves are given in Figure 2 and there is a clear trend of better graft and patient survival with donors <70 years of age.  However, Figure 4 shows that graft survival with “preferred” recipients was essentially identical when comparing grafts from donors <70 compared to >70.  However, when comparing graft survival from donors <40 compared to donors >70, there appeared to be a small advantage for the younger organs, though this did not meet statistical significance. (HR 1.2 CI 0.96-1.37).

My take: Given the shortage of available livers, the use of older donor organs is a necessity and can be accomplished without significant loss of grafts in selected patients.

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Subclinical Liver Transplant Rejection

A recent study (S Feng, JC Bucuvalas, et al. Gastroenterol 2018; 155: 1838-51) found a high prevalence of chronic histologic injury even among highly selected long term liver transplant recipients with consistently normal liver biochemical tests. The authors were able to enroll 157 patients. In addition to histology, the authors examined gene expression/microarray transcriptional analysis, and immunohistochemical staining.

Key findings:

  • Three clusters of patients were identified: interface activity (group 1, n=34), periportal/perivenular fibrosis without interface activity (group 2, n=45), and a group with neither (group 3, n=78).
  • In this cohort, 96 (61%) had Ishak Fibrosis of Stage 0-1, 27  (17%) had Stage 2, 33 (21%) had Stage 3, and 1 (1%) had Stage 4-5.
  • The authors identified a module of genes that regulate T-cell-mediated rejection that were associated with interface activity. Thus, interface activity in these patients connotes subclinical rejection, even in patients with consistently normal liver biochemistries.

What to do with this information:

“For patients whose biopsy samples harbor neither inflammation nor fibrosis, immunosuppression dose reduction may be reasonable…For patients, whose biopsy samples show fibrosis in the absence of inflammation, our data do not support any recommendations…for patients whose biopsy samples show interface hepatitis, our data indicate that dose reduction may be unwise.  Although the intuitive response may be to escalate immunosuppression, data evidencing the benefit of this approach are lacking.”

My take: This study shows why a liver biopsy has been important prior to reducing immunosuppression (in liver transplantation and autoimmune hepatitis). My question is whether the authors could identify a gene signature/biomarker (like their gene module) that could be used as an alternative to a liver biopsy.

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View from Golden Gulch Trail, Death Valley