Safety and efficacy of tacrolimus in pediatric liver recipients

Pediatric liver transplantation is now so successful that we expect more than 80% of children to survive into adolescence and adulthood. As the focus of care shifts toward long-term patient management, immunosuppressive regimens should, in addition to preventing acute and chronic rejection, promote good quality of life and be free of significant long-term side effects. Historically, the most effective immunosuppressive regimens have been based on induction with a combination of calcineurin inhibitors (cyclosporin or tacrolimus) and steroids. Usually, maintenance is monotherapy with cyclosporin or tacrolimus or dual therapy with low-dose alternate-day steroids to encourage growth. A number of studies, including long-term follow-up, have shown significantly lower incidences of rejection, hypertension, hyperlipidemia and cosmetic side effects in patients treated initially with tacrolimus compared with cyclosporin. The use of anti-interleukin-2 inhibitors as induction therapy, with low-dose tacrolimus or in combination with mycophenolate mofetil, has a key role in preventing significant renal dysfunction and reducing infection and rejection. Steroid-free immunosuppression is also proving to be an effective option for the management of pediatric liver recipients. The main challenges now facing pediatricians include ensuring long-term quality of life, optimizing immunosuppression while preventing associated adverse events, and managing a smooth transition from childhood to adolescence and adulthood.     

Efficacy and pharmacokinetics of tacrolimus oral suspension in pediatric liver transplant recipients

The use of tacrolimus in small pediatric graft recipients may require the availability of a suspension formulation for appropriate dose titration and easier administration. The pharmacokinetics (Pk) of an extemporaneously prepared oral suspension of tacrolimus (OST) was investigated in 15 pediatric liver transplant recipients, and was compared with the corresponding data with tacrolimus capsules (TC). Graft and patient survival rates were 100%. Acute rejection and steroid-resistant rejection were encountered in 9/15 and 3/15 patients, respectively. Comparison of Pk data showed a lower oral absorption of OST when compared with TC. No significant correlation could be made between the Pk parameters and rejection. Despite the lower bioavailability of OST when compared with TC, the rejection incidence was similar with both formulations (60% vs. 55%, respectively). Accordingly, the use of OST may constitute an alternative option for tacrolimus administration in low body weight organ recipients, to allow dosage titration in the early post-transplant weeks.     

Presentation of atopic disease in a large cohort of pediatric liver transplant recipients

Atopic disease occurs in solid organ transplant recipients with an increasingly recognized frequency. The time course for the development of these atopic diseases in liver transplantation has not been described. The objective was to characterize the atopic manifestations of children receiving chronic immunosuppression after orthotopic liver transplantation (OLT). Chart review and follow-up questionnaire were utilized for 176 OLT pediatric recipients at a single institution for manifestations of allergic disease. Atopic disease was present in 25 (14.2%) patients. Median age at transplant was 16 months with a median follow-up of 63 months. Food allergy and non-food related atopic symptoms presented at a median of 11.5 (IQR, 6-28) and 19 (IQR, 5-41) months post-transplantation, respectively. The median age at transplant of the non-atopic children was 72 months, higher than patients with atopy (p < 0.001). Food allergy and atopic skin disease symptoms were present in 40% and 56% of cases, respectively. Asthma, allergic rhinitis, or both were found in 66% of cases. The onset of symptoms of food allergy and eczema (median, 12 months post-transplantation) preceded symptoms of allergic rhinitis and asthma. (median of 27 and 30 months post-transplantation, respectively). Atopy occurs in ～14% of pediatric liver transplant recipients, with manifestations including food allergy, eczema, allergic rhinitis, and asthma.     

Long-term follow-up in adult living donors for combined liver/bowel transplant in pediatric recipients: a single center experience

Pediatric candidates for combined liver/bowel transplant (LBTx) experience a very high mortality on the cadaver waiting list. Our transplant center has successfully used adult living donors to treat pediatric candidates for LBTx. We report the long-term follow-up of this unique cohort of organ donors. The charts of six adult donors for LBTx performed between 2004 and 2007 were reviewed. All the pertinent clinical data were carefully reviewed and integrated with phone interviews of all donors. A total of six children (average age 13.5 months) received living donor LBTx. Average follow-up for the donors was 42 months (range 29-51). The donors' median age was 25 yr (19-32); five women and one man. The average median hospital stay was nine days. There were no peri-operative complications. At present all donors remain in good health. Three of the five mothers became pregnant after donation. Five of the six children are currently alive and well whereas one died with functioning grafts six months post-transplant due to plasmoblastic lymphoma. Living donor LBTx is an effective therapy for combined hepatic and intestinal failure in children less than five yr. The donor operation can be performed with minimal morbidity.     

Diaphragmatic hernias after pediatric liver transplantation: Experience of a high‐volume transplant center

Diaphragmatic hernias (DHs) are rare complications after pediatric liver transplantation (PLT). It is now widely accepted that DHs after liver transplantation (LT) is a pediatric related condition. PLTs (under of age 18) performed between January 2013 and June 2019 at Malatya Inonu University Institute of Liver Transplantation were retrospectively scanned. Study group consisting DHs and a control group were compared. Among 280 PLTs, 8 of them were complicated with DHs (%2.9). Median age of the patients with DH was 3.0 (0.8‐9.5) years. Median graft recipient weight ratio was 2.5 (0.9‐4.4). Five patients were below 5th percentiles in terms of pediatric weight growth chart at the time of LT. Also, 6 patients were below 5th percentiles in terms of pediatric height growth chart. There was no statistical difference between study and control groups. There are many risk factors mentioned in literature that may be primarily responsible for DHs after PLT. These factors are left lobe and large‐for‐size grafts, malnutrition, trauma or diathermy of diaphragmatic nerve and vessels and immunosuppressants. In our study, we could not specify any reason that differs in DHs. In our aspect, narrow diaphragma and thorax are exposed to high intra‐abdominal pressure from abdomen. Large‐for‐size grafts, which are specific to children, also may contribute to this affect. Excessive diathermy and trauma to diaphragmatic collaterals may aggravate the risk of DH. More patients are needed to make an exact conclusion, in order to evaluate with comparable study on this aspect.     

Cytokine concentrations and regulatory T cells in living donor and deceased donor liver transplant recipients

Outcomes of pediatric liver transplantation have constantly improved in the last decade. Living‐related liver transplantation does not seem to improve long‐term outcomes following liver transplantation, but few studies have evaluated immunological parameters of the alloimmune response after living vs. deceased donor organ transplantation. We analyzed numbers of regulatory T cells, lymphocyte subsets, and serum cytokine concentrations in 12 pediatric recipients of living‐related liver transplants and in 28 pediatric recipients of deceased donor organs during their annual follow‐ups. Transplant recipients who underwent living donor organ transplantation had significantly higher numbers of regulatory T cells and IL‐4 serum concentrations than recipients of deceased donor organs; both of these factors are associated with beneficial outcomes and transplantation tolerance. Living‐related liver transplantation may have potentially beneficial immunological aspects, although long‐term outcomes do not seem to be better in recipients of living donor organs than in recipients of deceased donor organs. Further studies are needed to compare immunological aspects of the two transplant procedures.     

Centrilobular necrosis as a manifestation of venous outflow block in pediatric malnourished liver transplant recipients – case reports

Gibelli NEM, Tannuri ACA, Andrade WC, Ricardi LRS, Tannuri U. Centrilobular necrosis as a manifestation of venous outflow block in pediatric malnourished liver transplant recipients – case reports. Abstract: CLN is a frequent histological finding in biopsies after pediatric: LT, and its pathogenesis has not yet been fully clarified and has different causes. Among the vascular causes, VOB is sometimes difficult to diagnose, especially when technical variants such as split‐liver, reduced‐liver, or living‐related LT are utilized. Three liver‐transplanted malnourished children (ages 12, 20, and 28 months) developed altered LFTs and post‐operative ascites with right pleural effusion (two cases) and jaundice (one case). Doppler ultrasound examinations were normal and liver biopsies showed CLN interpreted as severe ACR. There were no responses to the medical treatment. Additional investigation with CT angiography suggested obstructed hepatic vein drainage, which was confirmed by interventional radiology and angioplasty of the anastomosis between the hepatic vein and the inferior vena cava, with clinical and histological resolution. It is concluded that in malnourished children undergoing LT with technical variations, in which the occurrence of severe ACR is usually less common because of the severity of the patient condition, the finding of CLN should raise the possibility of VOB, so that excessive immunosuppression and its consequences can be avoided.     

Improved outcomes in pediatric liver transplantation for acute liver failure

Miloh T, Kerkar N, Parkar S, Emre S, Annunziato R, Mendez C, Arnon R, Suchy F, Rodriguez‐Laiz G, Del Rio Martin J, Sturdevant M, Iyer K. Improved outcomes in pediatric liver transplantation for acute liver failure.
Pediatr Transplantation 2010: 14:863–869. © 2010 John Wiley & Sons A/S. Abstract: OLT is a life‐saving option for ALF. Aim: To evaluate our outcomes in pediatric OLT for ALF. Methods: Retrospective review of our data between 1992 and 2007. Results: Of 142 children with ALF, 126 were listed, of which 40 spontaneously improved, nine died, and 77 underwent OLT (median waiting time four days). Fifty‐three children received deceased donor grafts (34 whole and 19 split grafts), and there were 24 living donor grafts. The one‐ and five‐yr patient survival was 87% and 80%, and graft survival 83% and 79%, respectively. Thirteen patients died after OLT, and there were nine retransplants in seven patients. Patient weight, length of stay, creatinine, and infection were significantly associated with death; increased weight and black ethnicity were associated with graft loss on univariate analysis, but not on multivariate analysis. There were no significant differences in patient survival (one and five yr), graft loss, or other complications between the groups. Conclusion: We report the largest single‐center study of OLT in pediatric ALF, demonstrating no difference in outcomes between different graft types. Our liberal use of segmental grafts may allow earlier OLT in this high‐risk cohort and contribute to our excellent outcomes.     

Hepatic venous reconstruction in pediatric living-related donor liver transplantation--experience of a single center

In pediatric patients submitted to living related liver transplantation, hepatic venous reconstruction is critical because of the diameter of the hepatic veins and the potential risk of twisting of the graft over the line of the anastomosis. The aim of the present study is to present our experience in hepatic venous reconstruction performed in pediatric living related donor liver transplantation. Fifty-four consecutive transplants were performed and two methods were utilized for the reconstruction of the hepatic vein: direct anastomosis of the orifice of the donor left or left and middle hepatic veins and the common orifice of the recipient left and middle hepatic veins (group 1-26 cases), and wide triangular anastomosis after creating a wide triangular orifice in the recipient inferior vena cava at the confluence of all the hepatic veins with an additional longitudinal incision in the inferior angle of the orifice (group 2-28 cases). In group 1, eight patients were excluded because of graft problems in the early postoperative period and five among the remaining 18 patients (27.7%) presented stricture at the site of the hepatic vein anastomosis. All these patients had to be submitted to two or three sessions of balloon dilatations of the anastomoses and in four of them a metal stent had to be placed. The liver histopathological changes were completely reversed by the placement of the stent. Among the 28 patients of the group 2, none of them presented hepatic vein stenosis (p = 0.01). The results of the present series lead to the conclusion that hepatic venous reconstruction in pediatric living donor liver transplantation must be preferentially performed by using a wide triangulation on the recipient inferior vena cava, including the orifices of the three hepatic veins. In cases of stenosis, the endovascular dilatation is the treatment of choice followed by stent placement in cases of recurrence.     

Living-related liver transplantation in children--a single center evaluation of the outcome of donor candidates and recipients

Abstract:  The aim was to study the outcome of donor candidate investigations for living-related donor liver transplantation from adult to child. The charts of 25 donor candidates were reviewed. All 22 recipients, of whom 18 had BA, were already listed for DD organ transplantation. Eleven donor candidates were accepted. Seven of them successfully donated the left lateral liver segment. At follow-up, all donors and recipients were well from the surgery. However, one donor developed Crohn's disease. In the four remaining cases the recipient deteriorated before transplantation was possible or other surgical approaches were utilized. For three candidates the investigations were never finalized, due to either clinical deterioration of the recipient or the availability of a DD organ. Eleven donor candidates were rejected. Four of them (three being parents of BA patients) had liver abnormalities. Another three were rejected for cardiopulmonary disorders and the remaining four for other reasons. We conclude that only seven out of 25 (28%) candidates donated a liver segment. The fact that parents of BA patients have potential liver pathology may be of importance for the understanding of the etiology of the disease and have possible implications for the choice of donors.     

Meso-Rex shunt for immediate portal revascularization in pediatric liver transplantation: first report

We describe the case of a 13-month-old girl transplanted for biliary atresia with PV hypoplasia. She received the left liver lobe of her mother and presented intraoperative portal thrombosis. Because of technical reasons, the opportunity to have conventional PV reconstruction using the donor left PV stump was lost. Immediate conversion to a meso-Rex shunt, using the recipient jugular vein as a bridge between the superior mesenteric vein and the graft Rex recessus, allowed excellent portal revascularization of the transplant. We suggest that synchronous meso-Rex shunt may constitute a valid alternative to truncal PV anastomosis during pediatric LT.     

Post-transplantation growth among pediatric recipients of liver transplantation

Improving a patient's quality-of-life (QOL) post-liver transplantation is of great importance. An aspect of improved QOL is the restoration of normal growth patterns in pediatric patients. To describe the post-transplantation growth patterns of 72 children included in the National Institute of Diabetes and Digestive and Kidney Diseases - Liver Transplantation Database (NIDDK-LTD), multilevel models were used, according to which children who waited more than a year for transplantation were smaller, compared with age and sex matched peers, at transplantation than children who waited less than a year while children who were growth retarded at transplantation experienced a larger yearly comparison height increase than children who were not growth retarded. The analysis also showed that boys older than 2 yr and younger than 13 yr at transplantation and girls older than 2 yr and younger than 11 yr at transplantation were significantly less growth retarded at transplantation than boys and girls under the age of 2 yr at transplantation.     

Primary tacrolimus (FK506) therapy and the long-term risk of post-transplant lymphoproliferative disease in pediatric liver transplant recipients

While the overall incidence of post-transplant lymphoproliferative disease (PTLD) in pediatric liver transplant recipients has been reported to be 4-11%, the long-term risk of PTLD associated with primary tacrolimus therapy is unknown. Therefore, in order to determine the incidence and long-term risk of PTLD, the present study examined 131 pediatric recipients who underwent liver transplantation (LTx) between October 1989 and December 1991 and received primary tacrolimus therapy. This cohort of children was evaluated over an extended time-period (until December 31 1996) with a mean follow-up of 6.3 yr. Actuarial Kaplan-Meier analysis was utilized to determine the risk of PTLD over time. The overall incidence of PTLD was 13% (17/131) with an average age of 4.3 +/- 0.75 yr at diagnosis. Pretransplant Epstein-Barr virus (EBV) serologies were negative in 82%, positive in 12%, and not available in 6% of the patients. The median time to diagnosis of PTLD post-Tx was 11.9 months (mean 16.4 +/- 3.9, range 1.7-63.0 months). Mean tacrolimus dose and plasma trough level (as evaluated by enzyme-linked immunosorbent assay [ELISA]) at the time of diagnosis was 0.32 +/- 0.06 mg/kg/day and 1.3 +/- 0.3 ng/mL, respectively. The cumulative long-term risk of PTLD was found to increase over time: 3% at 6 months, 8% at 1 yr, 12% at 2 yr, 14% at 3 yr, and 15% at 4 and 5 yr. Mortality from PTLD was 12% (two of 17 patients). Primary tacrolimus use in pediatric LTx has a long-term risk of PTLD approaching 15%, with the majority of episodes (78%) occurring in the first 2 yr, suggesting that intense EBV surveillance should occur early post-transplantation.     

Waiting list mortality for pediatric deceased donor liver transplantation in a Japanese living‐donor–dominant program

Living donor liver transplantation (LDLT) has become a major life‐saving procedure for children with end‐stage liver disease in Japan, whereas deceased donor liver transplantation (DDLT) has achieved only limited success. The annual number of pediatric liver transplantations is approximately 100‐120, with a patient 20‐year survival rate of 81.0%. In 2005, the liver transplantation program at the National Center for Child Health and Development in Tokyo, Japan, was initiated, with an overall number of 560 pediatric patients with end‐stage liver disease to date. In July 2010, our center was qualified as a pediatric DDLT center; a total of 132 patients were listed for DDLT up until February 2019. The indications for DDLT included acute liver failure (n = 46, 34.8%), metabolic liver disease (n = 26, 19.7%), graft failure after LDLT (n = 17, 12.9%), biliary atresia (n = 16, 12.1%), and primary sclerosing cholangitis (n = 10, 7.6%). Overall, 25.8% of the patients on the waiting list received a DDLT and 52.3% were transplanted from a living donor. The 5‐year patient and graft survivals were 90.5% and 88.8%, respectively, with an overall waiting list mortality of 3.0%. LDLT provides a better survival compared with DDLT among the recipients on the DDLT waiting list. LDLT is nevertheless of great importance in Japan; however, it cannot save all pediatric recipients. As the mortality of children on the waiting list has not yet been reduced to zero, both LDLT and DDLT should be implemented in pediatric liver transplantation programs.     

Duct-to-duct biliary reconstruction in pediatric living donor liver transplantation

The results of duct-to-duct biliary reconstruction in six pediatric patients who received a living donor liver transplant aged from 2 months to 11 yr old are reported. The graft was either entire or a part of the left lateral segments. The orifice of the bile duct of the graft was anastomosed to the recipients' hepatic duct in an end-to-end fashion by interrupted suture using 6-0 absorbable material. A transanastomotic external stent tube (4 Fr) was passed through the stump of the recipients' cystic duct. Mean time for reconstruction was 24 min. All the recipients survived the operation and reinitiated oral intake on postoperative day 3. There were no early biliary complications. One 5-yr-old boy suffered from an anastomotic stenosis 9 months after transplantation. He underwent re-anastomosis by Roux-en Y (R-Y) procedure and recovered uneventfully. Duct-to-duct anastomosis in pediatric living donor liver transplantation has benefits while the complication rate is comparable to R-Y reconstruction.     

Long‐term outcomes of pediatric living donor liver transplantation at a single institution

Oh SH, Kim KM, Kim DY, Lee YJ, Rhee KW, Jang JY, Chang SH, Lee SY, Kim J‐S, Choi BH, Park S‐J, Yoon CH, Ko G‐Y, Sung K‐B, Hwang G‐S, Choi K‐T, Yu E, Song G‐W, Ha T‐Y, Moon D‐B, Ahn C‐S, Kim K‐H, Hwang S, Park K‐M, Lee Y‐J, Lee S‐G. Long‐term outcomes of pediatric living donor liver transplantation at a single institution.
Pediatr Transplantation 2010: 14:870–878. © 2010 John Wiley & Sons A/S. Abstract: There have only been a few studies on the long‐term outcomes and prognostic factors after pediatric LDLT. We conducted a retrospective, single‐center assessment of the outcomes as well as the demographic and clinical factors that influenced the poor outcomes in 113 children aged <16 (median age 21 months; 6 months–15.5 yr) who underwent 115 LDLTs, predominantly for biliary atresia (60.9%) and FHF (14.8%), between 1994 and 2006 at Asan Medical Center. Left lateral segment or left lobe grafts were implanted into most of these children (86.9%) according to routine procedures. The overall rates of graft survival at one, five, and 10 yr were 89.6%, 83.0%, and 81.5%, respectively, and the overall rates of patient survival were 92.9%, 86.3%, and 84.8%, respectively. Virus‐related disease (41.2%) and chronic rejection (29.4%) were the major causes of mortality. On multivariate analysis, UNOS status 1a and 1b and chronic rejection were significant risk factors for both graft and patient loss, whereas the PELD score >25 was a significant risk factor for graft loss. Patient and graft survival may be related not only to post‐operative complications, but also to the patient’s preoperative clinical condition.     

Hyperammonemia in ornithine transcarbamylase‐deficient recipients following living donor liver transplantation from heterozygous carrier donors

Ornithine transcarbamylase deficiency (OTCD) is a urea cycle disorder of X‐linked inheritance, affecting the detoxification of excess nitrogen and leading to hyperammonemia (hyper‐NH₃). Living donor liver transplantation (LDLT) has been applied for the treatment of OTCD. This case series retrospectively reviewed two OTCD patients who experienced hyper‐NH₃ following LDLT. The first case was a 5‐year‐old girl who had onset of OTCD at 2 years of age. Ornithine transcarbamylase (OTC) enzyme activity was 62% for the donor and 15% for the recipient. The patient suffered from recurrence of hyper‐NH₃ within 2 months following LDLT. The second case was a 5‐year‐old girl who had onset of OTCD at 3 years of age. OTC enzyme activity was 42.6% for the donor and 9.7% for the recipient. The patient suffered hyper‐NH₃ for 12 days starting on the date of surgery. Both of the patients transiently required continuous veno‐venous hemodialysis; however, they are currently doing well without intensive medical treatment. The use of asymptomatic OTCD heterozygous donors in LDLT has been accepted with careful examination. However, an OTCD heterozygous carrier donor should be avoided if there is another donor candidate, due to the potentially fatal condition of hyper‐NH₃ following LDLT.