Posttransplantation lymphoproliferative disorder in pediatric liver transplantation

Essential oils as alternatives to antibiotics in swine production

This review article summarizes the efficacy, feasibility and potential mechanisms of the application of essential oils as antibiotic alternatives in swine production. Although there are numerous studies demonstrating that essential oils have several properties, such as antimicrobial, antioxidative and anti-inflammatory effects, feed palatability enhancement and improvement in gut growth and health, there is still a need of further investigations to elucidate the mechanisms underlying their functions. In the past, the results has been inconsistent in both laboratory and field studies because of the varied product compositions, dosages, purities and growing stages and conditions of animals. The minimal inhibitory concentration (MIC) of essential oils needed for killing enteric pathogens may not ensure the optimal feed intake and the essential oils inclusion cost may be too high in swine production. With the lipophilic and volatile nature of essential oils, there is a challenge in effective delivery of essential oils within pig gut and this challenge can partially be resolved by microencapsulation and nanotechnology. The effects of essential oils on inflammation, oxidative stress, microbiome, gut chemosensing and bacterial quorum sensing (QS) have led to better production performance of animals fed essential oils in a number of studies. It has been demonstrated that essential oils have good potential as antibiotic alternatives in feeds for swine production. The combination of different essential oils and other compounds (synergistic effect) such as organic acids seems to be a promising approach to improve the efficacy and safety of essential oils in applications. High-throughput systems technologies have been developed recently, which will allow us to dissect the mechanisms underlying the functions of essential oils and facilitate the use of essential oils in swine production.

Post-transplant malignancies in pediatric liver transplant recipients: Experience of two centers in Turkey

BACKGROUND/AIMS

A liver transplant is the preferred treatment for patients with end-stage liver disease, as it usually results in longterm survival. However, due to the use of chronic immunosuppressive therapy, which is necessary to prevent rejection, de novo cancer is a major risk after transplantation. The aim of this study was to assess the incidence of post-transplant malignancies in children after liver transplantations.

MATERIALS AND METHODS

The study group consisted of 206 liver transplant recipients, with no history of cancer, including hepatocellular carcinoma, in two liver transplantation centers in Turkey between 1997 and 2015. Data were obtained from patient's data chart.

RESULTS

In the study group, de novo cancer was diagnosed in 13 of the 206 patients. Post-transplant lymphoproliferative disease (PTLD) occurred in seven (53.8%) patients and other malignancies in six of the 13 patients. The types of PTLD were as follows: B-cell origin (n=2), Epstein-Barr virus (EBV)-related (n=2), T-cell origin (n=1), and Hodgkin's lymphoma (n=2). EBV DNA was isolated from seven patients, three of whom developed PTLD. The others developed Kaposi's sarcomas, Burkitt's lymphomas, cutaneous large-cell lymphomas, Hodgkin's lymphomas, and liver sarcomas.

CONCLUSION

After transplantation, immunosuppressive treatment is unavoidable, increasing the risk of malignancies. However, a close follow-up and periodic screening can reduce cancer-related mortality and morbidity.

Everolimus and reduced calcineurin inhibitor therapy in pediatric liver transplant recipients: Results from a multicenter, prospective study

In a 24-month, multicenter, single-arm, prospective study, 56 pediatric liver transplant patients with or without basiliximab induction were converted at 1-6 months post-transplant from standard calcineurin inhibitor (CN) therapy (± mycophenolic acid), to everolimus with reduced exposure to CNI (tacrolimus n=50, cyclosporine n=6). Steroid therapy was optional. Recruitment was stopped prematurely due to high rates of PTLD, treatment-related serious infections leading to hospitalization and premature study drug discontinuation. Subsequently, patients aged <7 years reverted to local standard-of-care immunosuppression. Mean tacrolimus concentration was above or near the upper end of the maintenance target range (2-5 ng/mL) until after month 6 post-enrollment. The primary variable, mean (SD) change in eGFR from baseline to month 12 (last observation carried forward), was +6.2 (19.5) mL/min/1.73 m² . Two patients experienced treated biopsy-proven acute rejection. No graft losses or deaths occurred. PTLD occurred in five patients (8.9%) (3/25 [12.0%] patients <2 years, 2/31 aged 2-18 years [6.5%]). Adverse events, serious adverse events, and discontinuation due to adverse events were reported in 100.0%, 76.8%, and 44.6% of patients, respectively. In conclusion, everolimus with reduced CNI improved renal function while maintaining antirejection potency in pediatric liver transplant patients but safety outcomes suggest that patients were overimmunosuppressed.

Posttransplantation lymphoproliferative disorder after pediatric solid organ transplantation: experiences of 20 years in a single center

PURPOSE

To evaluate the clinical spectrum of posttransplantation lymphoproliferative disorder (PTLD) after solid organ transplantation (SOT) in children.

METHODS

We retrospectively reviewed the medical records of 18 patients with PTLD who underwent liver (LT) or kidney transplantation (KT) between January 1995 and December 2014 in Seoul National University Children's Hospital.

RESULTS

Eighteen patients (3.9% of pediatric SOTs; LT:KT, 11:7; male to female, 9:9) were diagnosed as having PTLD over the last 2 decades (4.8% for LT and 2.9% for KT). PTLD usually presented with fever or gastrointestinal symptoms in a median period of 7 months after SOT. Eight cases had malignant lesions, and all the patients except one had evidence of Epstein-Barr virus (EBV) involvement, assessed by using in situ hybridization of tumor tissue or EBV viral load quantitation of blood. Remission was achieved in all patients with reduction of immunosuppression and/or rituximab therapy or chemotherapy, although 1 patient had allograft kidney loss and another died from complications of chemotherapy. The first case of PTLD was encountered after the introduction of tacrolimus for pediatric SOT in 2003. The recent increase in PTLD incidence in KT coincided with modification of clinical practice since 2012 to increase the tacrolimus trough level.

CONCLUSION

While the outcome was favorable in that all patients achieved complete remission, some patients still had allograft loss or mortality. To prevent PTLD and improve its outcome, monitoring for EBV infection is essential, which would lead to appropriate modification of immunosuppression and enhanced surveillance for PTLD.

Post-transplant lymphoproliferative disorder of the pediatric airway: Presentation and management

OBJECTIVE

Post-transplant lymphoproliferative disorder (PTLD) is a rare complication of immunosuppression with little consensus on its evaluation and management. The purpose of this contemporary review is to describe a pediatric patient with PTLD of the airway and review the literature to provide multidisciplinary recommendations regarding management.

DATA SOURCES

Retrospective chart and literature review.

REVIEW METHODS

A pediatric patient with PTLD of the airway is described. An extensive literature search to review the existing data on pediatric PTLD of the upper airway was also performed.

RESULTS

A pediatric patient with mixed fetal/embryonal hepatoblastoma developed laryngo-tracheal PTLD following liver transplantation. Diagnostic positron emission tomography (PET) scan demonstrated multiple sites of abnormal fluorodeoxyglucose (FDG) uptake within the larynx, distal esophagus, cervical lymph nodes, and abdomen concerning for PTLD. Laryngeal biopsy demonstrated Epstein-Barr virus (EBV) positive cells confirming the diagnosis. Rituximab therapy and reduction of immunosuppression resulted in resolution of his laryngeal disease in 3 months. An extensive literature search to review the existing data on pediatric PTLD of the larynx and trachea revealed 14 reported cases.

CONCLUSIONS

PTLD of the pediatric airway is an EBV-associated disease that requires a high index of suspicion as patients can often present with non-specific signs and symptoms but progress to have significant airway compromise. Evaluation consists of peripheral blood polymerase chain reaction (PCR) assays, biopsy, and PET/CT imaging. Management options include reduction of immunosuppression and/or systemic therapies.

A 13 year-old boy with post-transplantation lymphoproliferative disorder presenting with obscure gastrointestinal bleeding: a case report

One well recognized and potentially serious complication of chronic immunosuppression in organ transplant recipients is post-transplantation lymphoproliferative disorders (PTLD). This accounts for 20% of all malignancies in transplant recipients, which is four times higher than the general population (1,2). The diagnosis of PTLD is often difficult, due to various manifestations resulting in late diagnosis. We report an unusual presentation of PTLD in a pediatric patient where the diagnosis was achieved only after extensive investigation.

Biliary atresia: 50 years after the first kasai

Biliary atresia is a rare neonatal disease of unknown etiology, where obstruction of the biliary tree causes severe cholestasis, leading to biliary cirrhosis and death in the first years of life, if the condition is left untreated. Biliary atresia is the most frequent surgical cause of cholestatic jaundice in neonates and should be evoked whenever this clinical sign is associated with pale stools and hepatomegaly. The treatment of biliary atresia is surgical and currently recommended as a sequence of, eventually, two interventions. During the first months of life a hepatoportoenterostomy (a "Kasai," modifications of which are discussed in this paper) should be performed, in order to restore the biliary flow to the intestine and lessen further damage to the liver. If this fails and/or the disease progresses towards biliary cirrhosis and life-threatening complications, then liver transplantation is indicated, for which biliary atresia represents the most frequent pediatric indication. Of importance, the earlier the Kasai is performed, the later a liver transplantation is usually needed. This warrants a great degree of awareness of biliary atresia, and the implementation of systematic screening for this life-threatening pathology.

Impact of immunosuppression on the development of Epstein-Barr virus (EBV) viremia after pediatric liver transplantation

OBJECTIVES

Pediatric liver transplant (OLT) patients are at risk of posttransplant lymphoproliferative disease (PTLD) from Epstein-Barr virus (EBV). This study examined the impact of induction and immunosuppression on EBV viremia.

METHODS

A retrospective chart review was performed on 197 pediatric patients and induction regimen, immunosuppression levels, and EBV viremia were documented for 1 year post-OLT. Logistic regression models determined associations between induction, immunosuppression, and EBV.

RESULTS

Fifty six percent of patients developed EBV viremia. Incidence of EBV viremia was 73% with antithymocyte globulin (ATG), 63% with daclizumab, and 39% for neither, though the trend was not significant [ATG: odds ratio (OR) 0.19; 95% confidence interval (CI) 0.024-1.58; P = .125; daclizumab OR; 1.07; 95% CI 0.270-4.23; P = .925]. Tacrolimus immunosuppression levels were supratherapeutic 28.7% of the time; however, only supratherapeutic tacrolimus levels between 0 and 2 weeks increased EBV viremia at 2 to 4 weeks post-OLT (OR 1.80; 95% CI 1.10-2.94; P = .02). Three patients developed PTLD.

CONCLUSIONS

The use of ATG and daclizumab induction likely does not play a role in the development of EBV viremia. Supratherapeutic tacrolimus levels 0 to 2 weeks post-OLT impact the development of EBV viremia at 2 to 4 weeks. The incidence of PTLD was low, suggesting better EBV and immunosuppression monitoring plays an important role in reducing PTLD.

Trends in age for hepatoportoenterostomy in the United States

BACKGROUND

Biliary atresia is a rare but devastating disease for which hepatoportoenterostomy remains the primary intervention. Increased age at the time of hepatoportoenterostomy is associated with unfavorable outcomes. In this study, we examined trends in age at the time of hepatoportoenterostomy and explored hospital and patient factors associated with more timely diagnosis and treatment.

METHODS

Median ages of patients undergoing hepatoportoenterostomy for biliary atresia were compared using the Kids' Inpatients Database from 1997, 2000, 2003, and 2006. The patient and hospital factors associated with later treatment were compared.

RESULTS

Of 192 patients, 13.5% had surgery in 1997, 13.5% in 2000, 36.5% in 2003, and 36.5% in 2006. The overall median age was 65.5 days; the median age was 64 days in 1997, 57.5 days in 2000, 69 days in 2003, and 64 days in 2006 (P = .80). Overall, 71% of patients were treated at nonchildren's hospitals, and although the proportion has increased over time, the trend did not reach significance (P = .12). Hispanic and African American patients were more likely to undergo hepatoportoenterostomy after 60 days of life compared with white patients (Hispanic patients: odds ratio, 3.6; 95% confidence interval, 1.1-12.5; P = .04; African American patients: odds ratio, 2.2; 95% confidence interval, 0.8-6.3; P = .14). Compared with specialized children's centers, treatment at nonchildren's hospitals was associated with delayed hepatoportoenterostomy (odds ratio, 3.5; 95% confidence interval, 1.2-9.8; P = .02).

CONCLUSION

Although early hepatoportoenterostomy is associated with improved outcomes for children with biliary atresia, our study shows the median age at surgery has not significantly changed over 2 decades. Both hospital and socioeconomic factors play a role in the early treatment of biliary atresia.

Avoiding pitfalls: what an endoscopist should know in liver transplantation--part II

Over the last decade the number of patients undergoing transplantation has increased. At the same time, effective peri- and postoperative care and better surgical techniques have resulted in greater numbers of recipients achieving long-term survival. Identification and effective management in the form of adequate treatment is essential, since any delay in diagnosis or treatment may result in graft loss or serious threat to patient's life. Various aspects of endoscopic findings that can be commonly encountered among liver transplant recipients are discussed herein. Topics include: persistent and/or recurrent esophageal varices, reflux, Candida or cytomegalovirus (CMV) esophagitis, esophageal neoplasms, posttransplant peptic ulcer, biliary complications, posttransplant lymphoproliferative disorder (PTLD), Kaposi's sarcoma, CMV colitis and inflammatory bowel disease, colonic neoplasms, Clostridium difficile infection, and graft versus host disease (GVHD).

Impact of age at Kasai operation on its results in late childhood and adolescence: a rational basis for biliary atresia screening

BACKGROUND

Increased age at surgery has a negative impact on results of the Kasai operation for biliary atresia in infancy and early childhood. It remained unclear if an age threshold exists and if this effect persists with extended follow-up. In this study we examined the relationship between increased age at surgery and its results in adolescence.

METHODS

All patients with biliary atresia who were living in France and born between 1986 and 2002 were included. Median follow-up in survivors was 7 years.

RESULTS

Included in the study were 743 patients with biliary atresia, 695 of whom underwent a Kasai operation; 2-, 5-, 10-, and 15-year survival rates with native liver were 57.1%, 37.9%, 32.4%, and 28.5%, respectively. Median age at Kasai operation was 60 days and was stable over the study period. Whatever the follow-up (2, 5, 10, or 15 years), survival rates with native liver decreased when age at surgery increased (< or =30, 31-45, 46-60, 61-75, and 76-90 days). Accordingly, we estimated that if every patient with biliary atresia underwent the Kasai operation before 46 days of age, 5.7% of all liver transplantations performed annually in France in patients younger than 16 years could be spared.

CONCLUSIONS

Increased age at surgery had a progressive and sustained deleterious effect on the results of the Kasai operation until adolescence. These findings indicate a rational basis for biliary atresia screening to reduce the need for liver transplantations in infancy and childhood.

Clostridium difficile infection in solid organ transplant recipients

PURPOSE OF REVIEW

To provide a general understanding of Clostridium difficile infection with a focus on recent publications that evaluate the disease in solid organ transplant recipients.

RECENT FINDINGS

The incidence of C. difficile infection is increasing worldwide. Epidemics due to a hypervirulent C. difficile strain are associated with an escalating severity of disease. New evidence further supports basing initial treatment choice on disease severity.

SUMMARY

C. difficile is a significant pathogen in solid organ transplant recipients. Multiple risk factors are found in this population that may result in more severe disease. A high index of suspicion is necessary for the early diagnosis and treatment of C. difficile infection in transplant recipients. Metronidazole and vancomycin show equivalent efficacy in the treatment for mild-to-moderate disease, but vancomycin has demonstrated superiority in the treatment of severe disease. Surgical intervention is also an important consideration in the treatment of solid organ transplant recipients with severe colitis. Rigorous infection control practices are essential for preventing the spread of C. difficile within the hospital environment.

Pediatric liver transplantation: a pictorial essay of early and late complications

Orthotopic liver transplantation is currently the treatment of choice in patients with end-stage liver disease for which no other therapy is available. In children, segmental liver transplantation with living donor, reduced-size cadaveric, and split cadaveric allografts has become an important therapeutic option. However, the resulting expansion of the donor pool has increased the risk for postoperative vascular and biliary complications, which affect children more frequently than adults. Early recognition of these complications requires radiologic evaluation because their clinical manifestations are frequently nonspecific and vary widely. Doppler ultrasonography (US) plays the leading role in the postoperative evaluation of pediatric patients. Current magnetic resonance (MR) imaging techniques, including MR angiography and MR cholangiography, may provide a wealth of pertinent information and should be used when findings at US are inconclusive. Computed tomography is a valuable complement to US in the evaluation of complications involving the hepatic parenchyma as well as extrahepatic sites and is commonly used to guide percutaneous aspiration and fluid collection drainage. Familiarity with and early recognition of the imaging appearances of the various postoperative complications of pediatric liver transplantation are crucial for graft and patient survival.

Post-transplantation lymphoproliferative disorders localizing to the gastrointestinal tract after liver transplantation: report of five pediatric cases

Post-transplantation lymphoproliferative disorder (PTLD) is a life-threatening complication of organ transplantation. PTLD can occur in every kind of organ transplantation. From July 1992 to July 2004, five patients were diagnosed at our transplantation center with PTLD after pediatric liver transplantation. During this period, there were 52 pediatric patients (<18 yr) receiving an orthotopic liver transplantation (OLT) at our center. All five patients had transmural gastrointestinal (GI) PTLD, which occurred mostly in the stomach and duodenum. Epstein-Barr virus (EBV) in situ was demonstrated in each case. EBV viral load was noted to be an important risk factor. Treatment included dose reduction of immunosuppressants and anti-CD20 antibody infusion. Chemotherapy, including cyclophosphamide, doxorubicin, vincristine, and prednisolone, was given to three patients. Four patients have survived more than 10 months until now after treatment. The one who was unresponsive to chemotherapy and anti-CD20 antibody had diffuse metastasis and died of systemic candidiasis. In our series, each PTLD involved the GI tract. The mechanism of this phenomenon is unclear, but these five cases indicate the high incidence of PTLD in pediatric solid organ transplantation.