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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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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Liver Shorts November 2018

J Ge et al. Hepatology 2018; 68: 1101-10.  This study reviewed liver donation offers between 2010 to 2014.  This study found that 5.6% of men (293/5202) and 6.2% of women (179/2899) received a pediatric donor as a first offer.  Women, but not men, who received a pediatric first offer had a lower risk of waitlist mortality than with those who received adult organ offers. The authors recommend that “offers of pediatric donor liver be prioritized to women, who are generally shorter stature, once alllocation to the entire…pediatric waitlist pool has occurred.”

CA Chapin et al. Hepatology 2018; 68: 1087-1100.  This study found that patients with indeterminate pediatric acute liver failure (iPALF) have a unique pattern of dense CD8+ T-cell infiltrate that is also perforin-positive adn CD103-positive.  These CD8+ cells are a biomarker for immune dysregulation. These CD8+ dense pattern was found in the 27 of 33 patients with iPALF; 3 had moderate and 3 had minimal staining pattern (per table 2).  The dense CD8+ pattern was seen in 3 of 9 with autoimmune hepatitis and in 1 of 14 with other liver diseases.

E-D Pfister et al. Liver Transplantation 2018; 24: 1186-98.  This study examined patient (n=338) and graft survival in the pediatric population (median age 14.0 years) with Wilson’s disease (1968-2013).  Overall, patient survival was 87% at 1 year, 84% at 5 years, and 81% at 10 years.  Though, the survival was much improved since 2009.

JA Bezzerra et al. Hepatology 2018; 68: 1163-73. This review summarized a research workshop (June 2017) focused on the clinical and research challenges for biliary atresia.


More Acceptance (of livers), Better Outcomes

An important metric of liver transplantation outcome is not readily available: acceptance of organ offers.  A recent study (E Mitchell et al. Liver Transplantation 2018; 24: 803-809) showed a great deal of variability among pediatric liver transplantation centers in this metric.

The authors examined data from 2007-2015 with 4088 unique patients and 27,094 match runs. The range in organ acceptance rates was 5.1% to 14.6% with a median of 8.9%.

Key finding:

  • “Center-level acceptance rates were associated with wait-list mortality, with a >10% increase in the risk of wait-list mortality for every 1% decrease in a centers adjusted liver offer acceptance rate (odds ratio, 1.10, CI 1.01-1.19)

As noted in a previous post, Pediatric Liver Transplantation -Past Time to Split, larger centers generally have higher acceptance rates.

My take: This study adds to the literature regarding the inequities that some patients unknowingly face when listed in some centers.

Related article: HPJ van der Doef et al. Liver Transplantation 2018; 24: 810-9.  This article describes the wait-list mortality of young patients with biliary atresia.  Those listed before age 6 months and with higher MELD scores (>20) were at increased risk. Recognition of these factors may help improve allocation.

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Lots of Allergy & Autoimmunity Issues Following Solid Organ Transplantation

A recent retrospective cross-sectional cohort study (N Marcus et al. J Pediatr 2018; 196: 154-60, editorial page 10) identified 273 transplant recipients with a median followup of 3.6 years. This cohort included 111 liver transplant recipients, 103 heart transplant recipients, 52 kidney transplant recipients, and 7 multivisceral transplant recipients.

Key findings:

  • 92 (34%) developed allergy or autoimmunity after transplantation.
  • Allergic problems included eczema (n=44), food allergy (n=22), eosinophilic gastrointestinal disease (n=11), and asthma (n=28)
  • Autoimmunity problems developed in 6.6% (18) including autoimmune cytopenias (n=10). Two patients died due to autoimmune hemolytic anemia and hemophagocytic lymphohistiocytosis.
  • Allergic problems typically developed during the first year after transplantation and rarely after 5 years following transplantation.
  • ~20% required a change in immunosuppression
  • ~50% improved with time

In the editorial, the Dr. Helen Evans notes that the increasing reporting of atopic/allergic disorders could be due to recognition but could also be due, in part, to the widespread adoption of tacrolimus instead of cyclosporine for immunosuppression.

My take: Many have said that organ transplantation, which is life-saving, substitutes one problem for another.  This is an example of an additional burden, often related to immunosuppression, that patients and families have to manage afterwards.

Chattahoochee River, Island Ford

More on Time to Split (2018)

As noted in a blog last year (More on its Past Time to Split), increased use of split livers can reduce liver transplantation waitlist mortality in children.  Further justification for this approach is evident from a new study (DB Mogul et al. J Pediatr 2018; 196: 148-53, editorial pg 12) indicated that outcomes following split liver organs are equivalent to whole organ liver organs.

The authors examined two time periods: 2002-2009 and 2010-2015 using the Scientific Registry of Transplant Recipients. n=5715

Key findings:

  • 1-year survival from split liver transplant (SLT) improved during the later period compared to the initial period: 95% versus 89%. n=1626 (28.5% of all transplants)
  • 1-year survival from living donor liver transplant (LDLT) improved during the later period compared to the initial period: 98% versus 93%. n=661 (11.6% of all transplants)
  • 1-year survival from whole liver transplant (WLT) was essentially unchanged during the later period compared to the initial period: 95% versus 94%. n=3428 (60% of all transplants)

These data show that survival after transplant is no longer worsened by SLT and may be higher for LDLT than WLT.

The editorial by Dr. Bae Kim and Dr. Vakili note that there have been several proposals to encourage more use of SLTs.  One that was developed “would prioritize children <2 years old before local/regional adults except for those who were status 1 or who had a MELD score above 30.”  At this point, these efforts to favor SLT allocation have not been adopted by UNOS Board of Directors.

My take (borrowed from editorial): “The question should no longer be ‘To split or not to split?’ but rather ‘Why should we let children die when we can now split livers safely?'”

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