Post-transplant lymphoproliferative disorder after liver transplantation: Incidence, long-term survival and impact of serum tacrolimus level

Post-Transplant Lymphoproliferative Disorder at the Porta Hepatis Causing Hepatic Artery Stenosis and Cholestasis

BACKGROUND Post-transplant lymphoproliferative disorder (PTLD) encompasses a group of disorders ranging from hyperplastic to malignant lymphoid proliferations in the post-transplant period owing to immunosuppression, often in the setting of EBV transformation. PTLD is a rare complication of immunosuppression that, like lymphomas, can have a variable presentation based on disease localization. We report a case of PTLD mass effect at the porta hepatis for the first time in the literature, resulting in hepatic artery stenosis (HAS) and common hepatic duct obstruction. CASE REPORT A 54-year-old woman presented with cholestasis 4 months after receiving a deceased donor liver transplant. MRCP revealed a mass at the porta hepatis causing biliary compression, which resolved with subsequent biliary stenting. The woman presented again 3 weeks later with a similar presentation. CT revealed that the mass had enlarged, causing HAS, which resolved with subsequent hepatic artery stenting. The biopsy revealed PTLD, and the patient was successfully managed with rituximab and a reduction of her immunosuppressive regimen. CONCLUSIONS This case report describes a rare occurrence of PTLD, which particularly impacting the porta hepatis, resulting in HAS and compression of the bile duct. PTLD should be considered in the differential diagnosis for obstructive jaundice and hepatic artery compression, even in the early post-transplant months, when these symptoms are often attributed to surgical factors.

Effect of CYP 3A4*1B and CYP3A5*3 Gene Polymorphisms in Antirejection of Tacrolimus in Liver Transplant Patients

BACKGROUND

Tacrolimus is a substrate of CYP 3A5; to reduce the rate of liver injury and rejection in liver transplant (LT) recipients, it is feasible to optimize the administration of tacrolimus by adding CYP gene polymorphism.

METHODS

We divided 151 LT recipients randomly into an optimization group and a control group. All were tested routinely for clinical indicators such as FK506 trough concentration and biochemistry, and their complications and survival were observed. The optimization group additionally detected single nucleotide polymorphisms in the CYP 3A4*1B and CYP 3A5*3 genes.

RESULTS

There were no significant differences in tacrolimus dosage, FK506 trough concentrations, and concentration/dose value between the 2 groups. In the optimization group, all patients tested CYP 3A4*1B as wild type. CYP 3A5*3 detection classification included 35 with the G/G mutation (45.5%) and 36 A/G wild-type individuals (46.8%). The concentration/dose values of G/G mutant patients were significantly higher than those of A/G wild-type and A/A mutant patients (G/G vs. A/G; P < .05), and no significant difference in FK506.

CONCLUSION

The CYP 3A4*1B genotype has less influence on tacrolimus metabolism. The genetic polymorphism of CYP 3A5*3 is obvious and largely affects tacrolimus metabolism, and the variant patients need lower doses of tacrolimus to reach the target concentration.

Epstein-Barr virus-specific T-cell response in pediatric liver transplant recipients: a cross-sectional study by multiparametric flow cytometry

Background

Epstein-Barr virus (EBV) specific T-cell response measurement can help adjust immunosuppression in transplant patients with persistent infections. We aim to define T-cell responses against EBV in a cohort of pediatric liver-transplant patients.

Methods

Thirty-eight immunosuppressed pediatric liver-transplant patients (IP) and 25 EBV-seropositive healthy-adult controls (HC) were included in our cross-sectional study. Based on their EBV serological (S) and viral load (VL) status, patients were categorized into IP-SNEG, IP-SPOSVLNEG and IP-SPOSVLPOS groups. T-cell response was assessed at two timepoints by stimulating cells with EBV peptides (PepTivator®) and performing intracellular-cytokine and activation-induced marker staining. Background subtraction was used to determine EBV-specific T-lymphocyte frequency.

Results

Polyfunctional CD8+ T cells indicated previous EBV contact (IP-SNEG 0.00% vs IP-SPOS 0.04% and HC 0.02%; p=0.001 and p=0.01, respectively). Polyfunctional CD8+CD107a+IFNɣ+IL2-TNFα- profile was increased in serology-positive (IP-SNEG 0.01% vs IP-SPOS 0.13% and HC 0.03%; p=0.01 and p=0.50, respectively) and viral-load positive (IP-SPOSVLPOS 0.43% vs IP-SPOSVLNEG 0.07% and HC 0.03%; p=0.03 and p=0.001, respectively) patients. Central-memory cells were increased among serology-positive adults (IP-SNEG 0.00% vs IP-SPOS 0.13% and HC 4.33%; p=0.58 and p=0.002, respectively). At the second timepoint, IP-SNEG patients remained negative (first visit 0.01% vs second visit 0.00%, p=0.44). On the other hand, IP-SPOSVLPOS patients had cleared viral loads and, subsequently, decreased polyfunctional CD8+CD107a+IFNɣ+IL2-TNFα- cells (first visit 0.43% vs second visit 0.10%, p=0.81).

Conclusion

Polyfunctional CD8+ EBV-specific T-cell response allows detecting EBV previous contact in liver-transplant children. %CD8+CD107a+IFNɣ+IL2-TNFα- is increased in patients with positive viral loads. Central memory CD4+ T-cell population more effectively determines prior EBV-exposure in adults.

Infections After Liver Transplant -Timeline, Management and Prevention

Liver transplantation (LT) is the standard treatment for end- stage liver disease. Patient and graft survival have improved significantly in the last three decades owing to improvement in surgical technique, better perioperative management and better immunosuppressive regimens. However, LT recipients are at increased risk of infections, particularly in the first year after transplantation. The risk of infection is directly proportional to immunosuppressive regimen and graft function. In this review, we will briefly discuss the timeline of infections after liver transplant, preventive strategies and management of infectious complications.

Pediatric and adult liver transplantation in Bahrain: The experiences in a country with no available liver transplant facilities

BACKGROUND

Liver transplantation (LT) is a life-saving procedure for patients with end-stage liver disease and has become the standard and most effective treatment method for these patients. There are many indications for LT that vary between countries and settings. The outcome of LT depends on the available facilities and surgical expertise, as well as the types of liver graft donors available.

AIM

To assess the clinical characteristics of patients from Bahrain who underwent LT overseas, and analyze factors affecting their survival.

METHODS

In this retrospective cohort study, we reviewed the medical records and overseas committee registry information of all pediatric and adult patients who were sent overseas to undergo LT by the Pediatric and Medical Departments of Salmaniya Medical Complex and Bahrain Defence Force Hospital via the Overseas Treatment Office, Ministry of Health, Kingdom of Bahrain, between 1997 and 2023. Demo graphic data, LT indication, donor-recipient relationship, overseas LT center, graft type, post-LT medications, and LT complications, were collected. Outcomes measured included the overall and 5-year LT survival rate. Fisher's exact, Pearson χ2, and Mann-Whitney U tests were used to compare the pediatric and the adults' group in terms of clinical characteristics, donor-recipient relationship, medication, complications, and outcome. Survival analysis was estimated via the Kaplan-Meier's method. Univariate and multivariate analyses were used to detect predictors of survival.

RESULTS

Of the 208 eligible patients, 170 (81.7%) were sent overseas to undergo LT while 38 (18.3%) remained on the waiting list. Of the 170 patients, 167 (80.3%) underwent LT and were included in the study. The majority of the patients were Bahraini (91.0%), and most were males (57.5%). One-hundred-and-twenty (71.8%) were adults and 47 (28.3%) were children. The median age at transplant was 50.0 [interquartile range (IQR): 14.9-58.4] years. The main indication for pediatric LT was biliary atresia (31.9%), while that of adult LT was hepatitis C-related cirrhosis (35.0%). Six (3.6%) patients required re-transplantation. Most patients received a living-related liver graft (82%). Pediatric patients received more living and related grafts than adults (P = 0.038 and P = 0.041, respectively), while adult patients received more cadaveric and unrelated grafts. Most patients required long-term immunosuppressive therapy after LT (94.7%), of which tacrolimus was the most prescribed (84.0%), followed by prednisolone (50.7%), which was prescribed more frequently for pediatric patients (P = 0.001). Most patients developed complications (62.4%) with infectious episodes being the most common (38.9%), followed by biliary stricture (19.5%). Tonsilitis and sepsis (n = 12, 8.1% for each) were the most frequent infections. Pediatric patients experienced higher rates of infection, rejection, and early poor graft function than adult patients (P < 0.001, P = 0.003, and P = 0.025, respectively). The median follow-up time was 6.5 (IQR: 2.6-10.6) years. The overall survival rate was 84.4%, the 5-year survival rate, 86.2%, and the mortality rate, 15.6%. Younger patients had significantly better odds of survival (P = 0.019) and patients who survived had significantly longer follow-up periods (P < 0.001).

CONCLUSION

Patients with end-stage liver disease in Bahrain shared characteristics with those from other countries. Since LT facilities are not available, an overseas LT has offered them great hope.

Recurrent Acute Upper Gastrointestinal Bleed Due to Diffuse B-cell Lymphoma of the Duodenum in a Renal Transplant Patient: A Case Report and Literature Review

A patient status post (s/p) renal transplantation in 2014 presented with an upper gastrointestinal bleed (UGIB). The source of the bleed was found to be a large mass in the duodenum with histopathology from biopsies obtained during esophagogastroduodenoscopy revealing diffuse large B-cell lymphoma (DLBCL) of the duodenum. His mycophenolate was stopped, and the tacrolimus dose was reduced due to active malignancy. He was discharged and completed one cycle of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) before presenting back to ED with hemorrhagic shock from a large upper GI bleed requiring admission to the medical intensive care unit. Post-transplant lymphoproliferative disorders such as DBLCL can present 10 years from the transplant date. These malignancies are at high risk for bleed, especially after treatment with chemotherapy is initiated.

Complications in Post-Liver Transplant Patients

Liver transplantation (LT) is the treatment of choice for liver failure and selected cases of malignancies. Transplantation activity has increased over the years, and indications for LT have been widened, leading to organ shortage. To face this condition, a high selection of recipients with prioritizing systems and an enlargement of the donor pool were necessary. Several authors published their case series reporting the results obtained with the use of marginal donors, which seem to have progressively improved over the years. The introduction of in situ and ex situ machine perfusion, although still strongly debated, and better knowledge and treatment of the complications may have a role in achieving better results. With longer survival rates, a significant number of patients will suffer from long-term complications. An extensive review of the literature concerning short- and long-term outcomes is reported trying to highlight the most recent findings. The heterogeneity of the behaviors within the different centers is evident, leading to a difficult comparison of the results and making explicit the need to obtain more consent from experts.

A pediatric case series of catastrophic gastrointestinal complications of posttransplant lymphoproliferative disease with increasing incidence, high association with coronavirus disease 2019, higher mortality, and a plea for early endoscopy to prevent late fatal outcome

BACKGROUND

Posttransplant lymphoproliferative disorder is one of the most severe complications after transplantation, caused by uncontrolled proliferation of Epstein-Barr virus-positive B-cells in the setting of chronic immunosuppression. As one of the biggest transplant centers worldwide, we observed a potential increase in the number of patients with posttransplant lymphoproliferative disorder presenting with gastrointestinal symptoms in 1 year, during the coronavirus disease 2019 pandemic. There is limited information about dysregulation of the immune system following coronavirus disease 2019 infection, which may lead to Epstein-Barr virus reactivation in Epstein-Barr virus-positive B-cells and development of posttransplant lymphoproliferative disorder. Furthermore, there is no consensus in literature on a modality that can help in early diagnosis of posttransplant lymphoproliferative disorder with nonspecific gastrointestinal presentations before late and fatal complications occur.

CASE PRESENTATION

Our case series includes five Iranian (Persian) patients, three female (2, 2.5, and 5 years old) and two male (2 and 2.5 years old), who developed gastrointestinal posttransplant lymphoproliferative disorder after liver transplantation. All of our patients were on a similar immunosuppressant regimen and had similar Epstein-Barr virus serologic status (seronegative at time of transplantation but seropositive at time of posttransplant lymphoproliferative disorder diagnosis). Four patients had either a positive coronavirus disease 2019 polymerase chain reaction test or exposure within the family. Although all of our patients presented with nonspecific gastrointestinal symptoms, four patients developed late posttransplant lymphoproliferative disorder complications such as bowel perforation and obstruction. All five patients with gastrointestinal posttransplant lymphoproliferative disorder received chemotherapy, but only two survived and currently are continuing the therapy. In one of the surviving patients, prompt endoscopic investigation resulted in early diagnosis of posttransplant lymphoproliferative disorder and a better outcome.

CONCLUSION

Since 80% of our patients had exposure to coronavirus, a potential relationship might be suggested between the two. Furthermore, as we witnessed in one case, urgent endoscopic investigation in immunocompromised patients presenting with gastrointestinal symptoms can improve the clinical outcomes and therefore should be considered for early diagnosis of posttransplant lymphoproliferative disorder.

Complete Recovery After Immunosuppressive Treatment Change in a Patient With Posttransplant Lymphoproliferative Disorder

Posttransplant lymphoproliferative diseases are a rare but important cause of morbidity and mortality secondary to immunosuppression after solid-organ or bone marrow transplant. Generally, posttransplant lymphoproliferative diseases develop in the first 2 years after transplant, when immunosuppressive therapy is the most intense. Change or reduction in immunosup - pressive treatment is an option for treatment of posttransplant lymphoproliferative diseases. We evaluated the treatment of a patient with posttransplant lymphoproliferative disease after liver transplant. A 64-year-old man underwent liver transplant from a living donor (the patient's son) in 2011 to treat hepatocellular cancer secondary to chronic hepatitis B. Tacrolimus and mycophenolate mofetil were used for immunosuppression through 9 years after liver transplant. In the abdominal computed tomography performed in response to abdominal pain during follow-up in March 2019, multiple solid lesions were observed. A liver biopsy revealed posttransplant lymphoproliferative disease with diffuse large B-cell lymphoma. Fluorine-18 positron emission tomography/computed tomography imaging of the patient showed no pathology in favor of primary lymphoproliferative disease. Mycophenolate mofetil and tacrolimus treatment was changed to everolimus. In the follow-up dynamic magnetic resonance imaging examination that was performed at 3 months after treatment change, we observed that the lesion at liver segment 6 had regressed to 30 mm and several lesions with similar features were observed in the right lobe of the liver. Additional liver biopsy results were compatible with complete remission. The patient's clinical symptoms had fully regressed at 18 months after the diagnosis of PTLD, at the time of this writing. Ongoing radiological and clinical follow-up has shown complete remission. Change from calcineurin treatment to treatment with an inhibitor of the mechanistic target of rapamycin may be an essential and new option for treatment of posttransplant lymphoproliferative disease after liver transplant.

Belatacept-Based Maintenance Immunosuppression Controls the Post-Transplant Humoral Immune Response in Highly Sensitized Nonhuman Primates

Preexisting donor-specific antibodies (DSA) to MHC antigens increase the risk of antibody-mediated rejection (AMR) in sensitized transplant recipients and reduces graft survival. Pretransplant desensitization with costimulation blockade and proteasome inhibition has facilitated transplantation in our preclinical nonhuman primate (NHP) model. However, long-term graft survival is limited by rebound of DSA after transplantation. In this study, we performed kidney transplants between highly sensitized, maximally MHC-mismatched NHPs (n=14). At kidney transplantation, primates received T cell depletion with rhesus-specific anti-thymocyte globulin (rhATG; n=10) or monoclonal anti-CD4 and anti-CD8 antibodies (n=4). Maintenance immunosuppression consisted of belatacept and tacrolimus (n=5) or belatacept and rapamycin (n=9) with steroids. Rebound of DSA post-kidney transplantation was significantly reduced compared with maintenance immunosuppression with tacrolimus, mycophenolate, and steroids. Protocol lymph node biopsy specimens showed a decrease in germinal center activity, with low frequencies of T follicular helper cells and class-switched B cells after kidney transplantation. Combined belatacept and rapamycin was superior in controlling viral reactivation, enabling weaning of ganciclovir prophylaxis. Tacrolimus was associated with increased morbidity that included cytomegalovirus and parvovirus viremia and post-transplant lymphoproliferative disorder. All primates in the tacrolimus/belatacept group failed discontinuation of antiviral therapy. Overall, belatacept-based immunosuppression increased AMR-free graft survival by controlling post-transplant humoral responses in highly sensitized NHP recipients and should be further investigated in a human clinical trial.

Seropositivity for cytomegalovirus and PCR-EBV monitoring: Protective factors for posttransplant lymphoproliferative disorder in pediatric liver transplant

BACKGROUND

PTLD is a clinical condition with high mortality. Monitoring EBV replication can be a useful tool to avoid the development of PTLD.

MATERIALS AND METHODS

This was a retrospective analysis of 428 pediatric patients who underwent liver transplantation between 1989 and 2016. The patients were divided into 2 groups (transplanted before 2006, when PCR-EBV was not monitored, and after 2006, when PCR-EBV monitoring was started). Patients with continuous PCR measurements for EBV were evaluated for the impact of a reduction in immunosuppression or a change in immunosuppressants on the number of viral copies. A logistic regression model was applied to evaluate factors related to PTLD.

RESULTS

The prevalence of PTLD was 4.2%. After monitoring patients with PCR for EBV levels, a predominance of the most severe, monomorphic form of lymphoproliferative disorder was observed (p = .009). The PTLD mortality was 5%. There was a change in the PCR level after tacrolimus reduction (p = .002) and after tacrolimus exchange for mTOR (p = .008). The number of EBV copies was significantly higher (p = .029) in patients who developed PTLD. In the multiple regression model, seropositivity for CMV was an independent protective factor for lymphoproliferative disorder (OR=0.09; 95% CI 0.02-0.42), reducing the chance of having PTLD adjusted by serology for EBV by 91%.

CONCLUSIONS

Monitoring the EBV viral load by PCR seems to prevent the emergence of milder forms of lymphoproliferative disorder. Pretransplant seropositivity for CMV is a protective factor for PTLD.

Post-transplant Lymphoproliferative Disorder in Pediatric Liver Transplantation: A Population-based Study from Shiraz, Iran

Background: This study aimed to determine the prevalence of post-transplant lymphoproliferative disorder (PTLD) based on the clinical and epidemiological characteristics of donors and pediatric transplant recipients. Methods: This cross-sectional study was conducted on the patients who had experienced liver transplantation at Shiraz Transplant Center, Shiraz, Iran, from April 2007 to March 2017. Data on the epidemiological characteristics, underlying diseases, dosage of immunosuppressive drugs, and duration of drug consumption from the time of liver transplantation until the onset of PTLD for transplant recipients, and donors’ age, sex, and family relationship with recipients were collected using a data-gathering form. Log rank test was employed to determine the variations in the distribution of survival in different sex and age groups. Results: The study findings indicated that 49 out of the 1207 children who had undergone liver transplantation developed PTLD, revealing a prevalence of 4%. The results showed no significant relationship between gender and the incidence of PTLD (P = 0.13). However, the mean age of the cases with PTLD was 4.93 ± 1.07 years at the time of transplantation, while non-PTLD patients showed a higher mean age at that time (7.80 ± 5.54). The mean dose of the immunosuppressive drugs (dose/kg) consumed by the recipients was as follows: tacrolimus = 0.2753 ± 0.23435, prednisolone = 0.6761 ± 0.62218, cellcept = 0.0724 ± 0.12963, and sirolimus = 0.1078 ± 0.08813. The average consumption period of the above-mentioned drugs from the time of transplantation until the onset of PTLD was 14.7 ± 14.409 months. Based on the results, the five-year survival rate was much lower in the patients with PTLD compared to the non-PTLD patients (31% Vs. 72.7%). The survival distribution was significantly different based on sex and age groups (P = 0.59 and P = 0.06, respectively). Conclusions: The prevalence of the clinical and epidemiological features of the PTLD in the patients under the present investigation was similar to those of the patients in other hospitals. Recognizing the clinical and epidemiological characteristics of transplant recipients with and without PTLD and donors can provide a basis for managing these patients.

Post-transplant Lymphoproliferative Disorder in Recipient's Reconstructed Middle Hepatic Vein After Pediatric Living Donor Liver Transplant: A Case Report

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) is known as one of the most frequent post-transplant neoplastic diseases, which may lead to recipient and graft morbidity after liver transplant.

PATIENT

A 14-year-old boy received pediatric living donor liver transplant (right living graft) 29 months ago, with etiology of biliary atresia. During 22-month follow-up after transplant, computed tomography and positron emission tomography with computed tomography scan showed a single progressive mass locating in the graft cutting surface with occlusive reconstructed middle hepatic vein (MHV). Serology was negative for Epstein-Barr virus serology. Mild fever and pneumonia did not improve after 1-week intravenous antibiotics. PTLD was considered.

RESULTS

A surgical resection was scheduled and performed in compliance with the Helsinki Congress and the Istanbul Declaration. During laparotomy, a single mass located in the reconstructed MHV from segment V to the inferior vena cava was confirmed. Postoperative immunohistochemical result showed CD 3(+), CD 20(+), CD 38(+), CD 10(-), CD 56(-), Ki-67(+, 20%-30%), Epstein-Barr virus-encoded RNA(-), and Epstein-Barr virus nuclear antigen 2(-). Polymorphic PTLD was eventually diagnosed. No recurrence or new set lesions were detected after 6-month follow-up.

CONCLUSIONS

This is the first case describing PTLD may originate from reconstructed MHV after pediatric living donor liver transplant. As a life-threatening complication of liver transplant, surgical resection should be considered as a safe and feasible treatment for the single resectable mass.

Tacrolimus and Sirolimus Once Daily Monotherapy Regimen as a Safe and Effective Long-Term Maintenance Immunosuppressive Therapy in Pediatric Liver Transplantation

BACKGROUND

Long-term efficiency of attenuated immunosuppressive therapies is not well characterized in pediatric liver transplantation (LT).

OBJECTIVE

To assess the efficiency of tacrolimus once daily (TAC-OD) and sirolimus once daily (SLR-OD) immunosuppression in pediatric LT.

METHODS

We retrospectively evaluated 59 children who underwent LT in our center during 2002 to 2016. Those including children who underwent planned decrease in immunosuppressant dose (stable clinical conditions after 2 years of LT), and those who underwent unplanned decrease in immunosuppressant dose (because of complications such as post-transplant lymphoproliferative disorder [PTLD] and renal failure).

RESULTS

25 of 59 children underwent planned decrease in immunosuppressant dosage (mean±SD duration of 4.5±1.8, range: 3-11 years); 34 had unplanned decrease (mean±SD of 1.3±0.6, range: 0.5-2.6 years). 19 of 25 children with planned conversion received TAC-OD; 6 received SLR-OD (22 with 1 mg/day dose, and 3 with 1 mg every two days). Of 34 children with unplanned conversion, 27 received TAC-OD, 7 SLR-OD (25 children with 1 mg/day, 7 with 1 mg every two days, 1 with 0.5 mg/day TAC, and 1 with 0.5 mg TAC every two days). We found no adverse events including acute or chronic graft rejection, renal insufficiency, infections, PTLDs, or cardiovascular thrombotic events after initiation of the modified immunosuppression in none of the groups.

CONCLUSION

TAC-OD or SLR-OD monotherapies are safe and effective for long-term management of LT children with either stable clinical conditions or those with LT complications.

It takes a village: primary care of the pediatric liver transplant recipient

PURPOSE OF REVIEW

Long-term survival is now the rule rather than the exception for infants and children who undergo liver transplantation for end-stage liver disease, metabolic liver conditions and a variety of other indications. Pediatricians and primary care providers play vital roles in the care and management of this patient population. The purpose of this review is to highlight key aspects important to the care of the pediatric liver transplant recipient.

RECENT FINDINGS

Significant advances in immunosuppressive therapies and surgical techniques have contributed to improved graft and patient survival rates, shifting the focus beyond immediate survival to strategies to minimize comorbidities related to long-term immunosuppression during growing years, attend to patient and parent-reported outcomes and enhance quality of life. A multidisciplinary approach allows for monitoring and surveillance of both routine (growth, nutritional rehabilitation, cognitive development, mental and psychosocial health, contraception and daily activities) and transplant-related (adverse effects of immunosuppression, susceptible infections, extra-hepatic systems, transition from childhood to adolescence to adulthood) themes.

SUMMARY

Effective communication between the primary care physician and the transplant team is imperative for optimizing best outcomes. The primary care provider should be aware of the multifacet nature of posttransplant management, which includes medication regimens, common complications and infections.

De novo malignancies after liver transplantation: The effect of immunosuppression-personal data and review of literature

BACKGROUND

Immunosuppression has undoubtedly raised the overall positive outcomes in the post-operative management of solid organ transplantation. However, long-term exposure to immunosuppression is associated with critical systemic morbidities. De novo malignancies following orthotopic liver transplants (OLTs) are a serious threat in pediatric and adult transplant individuals. Data from different experiences were reported and compared to assess the connection between immunosuppression and de novo malignancies in liver transplant patients.

AIM

To study the role of immunosuppression on the incidence of de novo malignancies in liver transplant recipients.

METHODS

A systematic literature examination about de novo malignancies and immunosuppression weaning in adult and pediatric OLT recipients was described in the present review. Worldwide data were collected from highly qualified institutions performing OLTs. Patient follow-up, immunosuppression discontinuation and incidence of de novo malignancies were reported. Likewise, the review assesses the differences in adult and pediatric recipients by describing the adopted immunosuppression regimens and the different type of diagnosed solid and blood malignancy.

RESULTS

Emerging evidence suggests that the liver is an immunologically privileged organ able to support immunosuppression discontinuation in carefully selected recipients. Malignancies are often detected in liver transplant patients undergoing daily immunosuppression regimens. Post-transplant lymphoproliferative diseases and skin tumors are the most detected de novo malignancies in the pediatric and adult OLT population, respectively. To date, immunosuppression withdrawal has been achieved in up to 40% and 60% of well-selected adult and pediatric recipients, respectively. In both populations, a clear benefit of immunosuppression weaning protocols on de novo malignancies is difficult to ascertain because data have not been specified in most of the clinical experiences.

CONCLUSION

The selected populations of tolerant pediatric and adult liver transplant recipients greatly benefit from immunosuppression weaning. There is still no strong clinical evidence on the usefulness of immunosuppression withdrawal in OLT recipients on malignancies. An interesting focus is represented by the complete reconstitution of the immunological pathways that could help in decreasing the incidence of de novo malignancies and may also help in treating liver transplant patients suffering from cancer.

Update on posttransplant lymphoproliferative disease

PURPOSE OF REVIEW

Posttransplant lymphoproliferative disorder (PTLD), frequently associated with Epstein-Barr virus (EBV), is one of the most serious complications leading to worse patient and graft outcomes. Hence, we summarize in this review relevant studies published about PTLD in the last 18 months.

RECENT FINDINGS

Recent studies have improved the knowledge about epidemiology, prophylaxis, diagnosis and PTLD treatment. Special interest has developed in improving the last PTLD classification of the World Health Organization, increasing the accuracy of diagnostic tests for EBV viral load quantification and discriminating the genetic differences between PTLD types. There seems to be no real advantage in the use of antiviral drugs for prophylaxis, but better results in therapeutic approaches are being obtained mainly with the use of rituximab with or without chemotherapy, but also with the possibility of using adoptive T-cell therapy or new drugs.

SUMMARY

PTLD continues being a complication that requires continued effort of the scientific community to reduce its incidence and to develop better diagnostic tests and new strategies that improve results in prophylaxis and treatment.

Long-term care of transplant recipients: de novo neoplasms after liver transplantation

PURPOSE OF REVIEW

Since the first liver transplantation in the early 1960s, there have been significant improvements in the recipients' long-term outcome. Patients who have undergone transplantation are exposed to a high risk of developing neoplastic disease, not only because of their chronic immunosuppression, but also related to physiological aging, lifestyle, chronic viral infections, liver disease cause, and carcinogenic immunosuppressants. The present review covers the latest and most relevant data on de novo neoplasms after liver transplantation, and discusses their implications for clinical practice.

RECENT FINDINGS

Given the impact of de novo neoplasms, in terms of morbidity and mortality, transplant teams must be prepared to diagnose and treat these conditions promptly. Dedicated cancer screening protocols are warranted. Although surveillance strategies are based on data concerning the general population, they should be customized in the light of each transplant recipient's risk factors. The resulting risk stratification is crucially important to the design of early intervention programs, and for addressing the modulation of individualized immunosuppressive regimens.

SUMMARY

De novo malignancies are a significant issue for the liver transplant population, but targeted screening programs have shown that survival rates similar to those of nonimmunosuppressed patients can be achieved. New oncological surveillance strategies covering the prophylaxis, monitoring, and treatment of de novo neoplasms should take high priority in clinical research.

Colorectal Cancer Characteristics and Outcomes after Solid Organ Transplantation

Background

Individuals after solid organ transplant may develop secondary malignancies. In our clinical practice, we noted an increasing number of individuals who developed colorectal cancers after solid organ transplantation. The primary aim of this study was to describe the characteristics and outcomes of the patients who developed colorectal cancer after solid organ transplant.

Materials and Methods

Data was gathered and merged from several registries at Mayo Clinic to identify all patients who received a diagnosis of colon or rectal cancer and solid organ transplant. Continuous variables were summarized as mean (standard deviation) and median (range), while categorical variables were reported as frequency (percentage). Time to colorectal cancer after transplant and overall survival after cancer diagnosis were estimated using Kaplan-Meier method.

Results

Initially, 115 colorectal cancer patients who also had a transplant were identified. The diagnosis of colorectal cancer was noted after solid organ transplant in 63 patients. The mean age at transplant was 57 years. Majority had received a kidney transplant (44.4%) followed by liver (36.5%). The median time to develop colorectal cancer was 59.3 months (range: 4.4-251.4 months). 15 (24.6%) were stage 4 at diagnosis and 13 (21.3%) had stage 3 colorectal cancer. Median overall survival was 30.8 months; 5-, 10- and 15-year survival were noted to be 42.5%, 17.9%, and 7.5%, respectively. None of the stage 4 patients were alive at 5 years; 5-year survival rate for stage 1, 2, and 3 patients was 77%, 50%, and 42%, respectively.

Conclusions

Our study reports on one of the largest cohorts of patients of colorectal cancer that developed the cancer after solid organ transplant. Survival is extremely poor for advanced cases. However, long-term survivors are noted who developed the cancer at a relatively early stage. Colorectal screening recommendations may need to be revised for patients after solid organ transplant.

Infections in Liver Transplantation

Liver transplantation has become an important treatment modality for patients with end-stage liver disease/cirrhosis, acute liver failure, and hepatocellular carcinoma. Although surgical techniques and immunosuppressive regimens for liver transplantation have improved significantly over the past 20 years, infectious complications continue to contribute to the morbidity and mortality in this patient population. The use of standardized screening protocols for both donors and recipients, coupled with targeted prophylaxis against specific pathogens, has helped to mitigate the risk of infection in liver transplant recipients. Patients with chronic liver disease and cirrhosis have immunological deficits that place them at increased risk for infection while awaiting liver transplantation. The patient undergoing liver transplantation is prone to develop healthcare-acquired infections due to multidrug-resistant organisms that could potentially affect patient outcomes after transplantation. The complex nature of liver transplant surgery that involves multiple vascular and hepatobiliary anastomoses further increases the risk of infection after liver transplantation. During the early post-transplantation period, healthcare-acquired bacterial and fungal infections are the most common types of infection encountered in liver transplant recipients. The period of maximal immunosuppression that occurs at 1–6 months after transplantation can be complicated by opportunistic infections due to both primary infection and reactivation of latent infection. Severe community-acquired infections can complicate the course of liver transplantation beyond 12 months after transplant surgery. This chapter provides an overview of liver transplantation including indications, donor-recipient selection criteria, surgical procedures, and immunosuppressive therapies. A focus on infections in patients with chronic liver disease/cirrhosis and an overview of the specific infectious complications in liver transplant recipients are presented.

Very late onset post-transplant diffuse large B cell lymphoma in a liver transplant recipient with hepatitis B: A case report

RATIONALE

Post transplantation lymphoproliferative disorder (PTLD) is a rare but severe complication. Epstein-Barr virus (EBV) is considered an important pathogen for PTLD and EBV deoxyribonucleic acid (DNA) load is widely monitored to detect PTLD early. Hepatitis B virus (HBV) infection is rarely reported to be related with PTLD. We report a case of EBV negative (EBV), HBV positive (HBV) diffuse large B cell lymphoma in a patient 12 years after liver transplantation.

PATIENT CONCERNS AND DIAGNOSIS

A 52-year-old man complained of worsening appetite, abdominal distension, and pruritus. Abdominal computed tomography (CT) detected a huge retroperitoneal mass and pathology of the fine needle biopsy established the diagnosis of diffuse large B cell lymphoma. Virology showed active hepatitis B viral duplication and EBV DNA was negative.

INTERVENTION

Treatment modalities for this patient included: reduction and subsequent cessation of immunosuppression; antiviral therapy for HBV with entecavir and adefovir; conventional chemotherapy consisting of cyclophosphamide, epirubicin, vindesine, and prednisone, followed by radiotherapy. He achieved complete remission (CR) and was kept on entecavir treatment afterwards.

OUTCOMES

He has been in remission for 2 years.

LESSONS

HBV infection might have played some role in this very late onset EBV PTLD patient. Therefore, HBV serology and HBV load should be monitored during the follow-up of HBV surface antigen positive (HBsAg) transplant recipients and life-long antiviral therapy is required.

Histological findings in protocol biopsies following pediatric liver transplant: Low incidence of abnormalities at 5 years

Histological abnormalities, including chronic hepatitis, fibrosis, and steatosis, are increasingly reported in liver biopsies of children after LT. These changes may be progressive and represent a form of rejection. Liver biochemistry is often initially normal. Our LT program began in 2002, utilizing tacrolimus and low-dose steroids for the first year post-LT. Patients undergo a protocol biopsy at 1 year post-LT prior to stopping steroids, then at 5 years and every 5 years thereafter. Target tacrolimus levels are 5-8 μg/L and 3-5 μg/L after 3 and 12 months, respectively. Between 2002 and 2009, 51 LT were performed; 50 (98%) and 49 (96%) patients survived for 1 and 5 years, respectively. A total of 43 patients (median age at LT 2.3 years) underwent a protocol biopsy at 1 year (16 male; median time post-LT 12.5 months), and 44 (20 male; median time post-LT 5.1 years) at 5 years. By 5 years, 3 had transferred to adult services; 1 was re-transplanted for graft failure and 1 moved overseas. Biopsies were reviewed by 2 pathologists. Most patients (31/44) were on tacrolimus monotherapy at 5 years. At 1 and 5 years, 29 of 43 (67.5%) and 31 of 44 (71%) biopsies were normal, respectively. Two of 44 had chronic allograft hepatitis at 5 years. Two of 43 and 1 of 44 had isolated fibrosis, 3 of 43 and 3 of 44 steatosis, and 3 of 43 and 4 of 44 acute rejection at 1 and 5 years, respectively. Other findings included predominantly biliary changes (6/43 & 3/44 at 1 and 5 years, respectively). Tacrolimus levels at 5 years were slightly higher than anticipated (median trough level 5.8 μg/L). With an immunosuppressive regimen of tacrolimus and low-dose steroids for 1 year followed by tacrolimus monotherapy thereafter, the majority of PLB were normal and no progressive changes were observed at 5 years. Compared to other LT programs, we have lower rates of chronic allograft hepatitis, steatosis, and fibrosis at 5 years. However, the tacrolimus levels at 5 years were higher than planned and this may have played a role. Further evaluation is also required to determine the potential long-term adverse effects of corticosteroid use on linear growth and bone mineral density.

Mitofusin-2 mediated mitochondrial Ca2+ uptake 1/2 induced liver injury in rat remote ischemic perconditioning liver transplantation and alpha mouse liver-12 hypoxia cell line models

AIM

To investigate the protective mechanism of mitofusin-2 (Mfn2) in rat remote ischemic perconditioning (RIC) models and revalidate it in alpha mouse liver-12 (AML-12) hypoxia cell lines.

METHODS

Sprague-Dawley rats were divided into three groups (n = 6 each): sham, orthotopic liver transplantation and RIC. After operation, blood samples were collected to test alanine aminotransferase and aspartate aminotransferase. The liver lobes were harvested for histopathological examination, western blotting (WB) and quantitative real-time (qRT)-PCR. AML-12 cell lines were then subjected to normal culture, anoxic incubator tank culture (hypoxia) and anoxic incubator tank culture with Mfn2 knockdown (hypoxia + Si), and data of qRT-PCR, WB, mitochondrial membrane potential (ΔΨm), apoptosis, endoplasmic reticulum Ca²⁺ concentrations and mitochondrial Ca²⁺ concentrations were collected.

RESULTS

Both sham and normal culture groups showed no injury during the experiment. The RIC group showed amelioration of liver function compared with the orthotopic liver transplantation group (P < 0.05). qRT-PCR and WB confirmed that Mfn2-mitochondrial Ca²⁺ uptake 1/2 (MICUs) axis was changed (P < 0.005). In AML-12 cell lines, compared with the hypoxia group, the hypoxia + Si group attenuated the collapse of ΔΨm and apoptosis (P < 0.005). The endoplasmic reticulum Ca²⁺ decrease and mitochondrial Ca²⁺ overloading observed in the hypoxia group were also attenuated in the hypoxia + Si group (P < 0.005). Finally, qRT-PCR and WB confirmed the Mfn2-MICUs axis change in all the groups (P < 0.005).

CONCLUSION

Mfn2 participates in liver injury in rat RIC models and AML-12 hypoxia cell lines by regulating the MICUs pathway.

The Care of the Postliver Transplant Patient

Since 1988 nearly 150,000 liver transplants have been performed in the United States. Over the past 3 decades the indications for liver transplant have changed from end-stage liver disease from alcohol and cholestatic liver diseases to hepatitis C and most recently nonalcoholic fatty liver disease. Liver transplant recipients are living longer with 10-year survival rates exceeding 60%. Gastroenterologists are likely to encounter or consult on postliver transplant recipients as they live longer and seek care closer to home. Complications after liver transplant are related to immunosuppression, malignancy, recurrent disease, and conditions associated with metabolic syndrome. This review will discuss postliver transplant care and complications in liver transplant recipients.

Post-transplant lymphoproliferative disorder after solid-organ transplant in children

The post-transplant lymphoproliferative disorders (PTLD) are a diverse group of potentially life-threatening conditions affecting organ transplant recipients. PTLD arises in the setting of an attenuated host immunologic system that is manipulated to allow a foreign graft but then fails to provide adequate immune surveillance of transformed malignant or premalignant lymphocytes. The diversity of biological behavior and clinical presentation makes for a challenging clinical situation for those involved in the care of children with PTLD occurring after solid-organ transplantation. This review details a large transplant center's multidisciplinary approach to monitoring for PTLD and systematic approach to intervention, which has been essential for early recognition and successful treatment.