Liver transplantation in pediatric patients: twenty years of experience at the University of Wisconsin

Developments in surgical technique, immunosuppression, organ procurement and preservation, and patient selection criteria have resulted in improved long-term patient and graft survival after pediatric liver transplantation. In this study, we examined the results of 196 liver transplants performed in 155 pediatric patients at University of Wisconsin Children's Hospital. Patients were divided into two groups according to age at the time of liver transplant. Infants under 12 months of age comprised Group 1 (n=74) and children from one to 18 yr comprised Group 2 (n=122). Outcomes for whole, reduced-size, and split liver transplantation were compared in infants and children. Biliary atresia was the most common indication in both groups. Patients underwent 128 whole size, 50 reduced size, and 18 split liver transplants. Forty-one retransplantations were performed in 14 infants (18.9%) and in 27 children (22.1%). One hundred eleven patients (56.6%) had one or more rejection episode [37 infants (50.0%) and 74 children (60.6%)]. Thirty-nine patients (19.8%) developed CMV infections, 42 (21.4%) developed EBV infections, and 14 developed PTLD (six infants and eight children). Thirty-six patients (18.3%) developed HAT. Seven patients (4.5%) developed malignancy (one infant and six children). Out of 155 patients, 33 (21.3%) died during the study period. The most common etiology of mortality included central nervous system pathology (n=7; 4.5%), sepsis (n=6; 3.8%), and cardiac causes (n=6; 3.8%). One-, five-, and 10-yr actuarial patient survival was 86, 79, and 74% in infants and 90, 83 and 80% in children. Graft survival at one, five, and 10 yr was 77, 73 and 71% in infants and 88, 81 and 78% in children, respectively. Despite its technical challenges, the outcomes of liver transplantation in pediatric patients with end-stage liver disease are excellent and result in significant long-term patient and graft survival.

Retransplantation for hepatitis C: results of a U.S. multicenter retransplant study

It is widely perceived that outcomes are relatively poor following retransplantation (reTX) for recurrent of hepatitis C virus (HCV) infection. Transplant centers debate the utility of offering another liver to these patients. A U.S. study group was formed to retrospectively compare survival after reTX in patients with recurrent HCV (histologically proven) and those transplanted for other indications greater than 90 days after first transplantation, from 1996 to 2004. Patients were divided into 3 groups; group 1: HCV reTX (n = 43), group 2: non-HCV reTX (n = 73), and group 3: recurrent HCV but no reTX (n = 156). They were predominantly male, Caucasian, with mean age of 47.2 yr. The commonest indications for non-HCV reTX were chronic rejection (36%), hepatic artery thrombosis (31%) and recurrent primary sclerosing cholangitis (17%). Duration of hospitalization, number of intensive care unit (ICU) days, and time interval from listing to transplantation or reTX were similar between reTX groups. The 1-yr and 3-yr survival rates after reTX were also similar for HCV reTX and non-HCV reTX groups (1 yr, 69% vs. 73%; 3 yr, 49% vs. 55%). Model for End-Stage Liver Disease (MELD) scores were not predictive of survival from reTX. However, with a MELD score of >30 in the non HCV group, survival was <50%. In the recurrent HCV not undergoing reTX group, 30% were reevaluated for reTX but only 15% were listed for reTX and the 3-yr survival was 47%. The most common reasons for not listing for reTX were recurrent HCV within 6 months (22%), fibrosing cholestatic hepatitis (19%), and renal dysfunction (9%). In conclusion, patients retransplanted for recurrent HCV had similar 1-yr and 3-yr survival when compared to patients undergoing reTX for other indications. MELD scores were not predictive of post-reTX survival. Survival was <50% in the non-HCV reTx group with MELD score of >30. Many patients with recurrent HCV are not considered for reTX and die from recurrent disease.

Predictors of graft and patient survival in hepatitis C virus (HCV) recipients: model to predict HCV cirrhosis after liver transplantation

BACKGROUND

Hepatitis C virus (HCV) recurrence after liver transplantation (LT) is almost universal, but the natural history of recurrent HCV in the allograft is highly variable. Our study had two aims: 1) to assess the impact of different pre- and postLT factors on graft and patient survival in HCV transplant recipients and 2) to create a model which may predict the patients at risk for HCV-related graft cirrhosis at 5 years postLT.

METHODS

A total of 168 LTs were considered for this study. Univariate and multivariate Cox proportional hazards regression model was used, as well as logistic regression analysis to create a model of prediction of HCV cirrhosis within 5 years after LT.

RESULTS

Predictive factors for both decreased graft and patient survival included patients recently transplanted (2000-2004), induction without azathioprine, short-term therapy with mycophenolate mofetil and prednisone (< or =6 months), presence of early cholestasis, histologically proven early recurrence of hepatitis C. Recipient human leukocyte antigen DR3 positivity, presence of early cholestasis, and donor age >50 years were identified as independent predictors of graft cirrhosis within 5 years. A predictive model was established in order to calculate at 6 months a risk score for graft HCV cirrhosis within 5 years postLT using a formula that included the identified independent predictors. The area under receiver operating characteristic curve was 0.83, indicating a good ability to predict medium-term HCV allograft cirrhosis.

CONCLUSION

This model may be a useful tool for better identifying high-risk HCV patients who should be selected for early initiation of antiviral therapy.

Strategies for Epstein–Barr virus monitoring, detection and therapy in post-transplant lymphoproliferative disorder

Epstein–Barr virus (EBV) is a significant cause of morbidity and mortality in solid-organ transplant (SOT) recipients. The most serious complication of EBV infection in this population is post-transplant lymphoproliferative disorder (PTLD). EBV-viral load monitoring can be used to predict those SOT patients at high risk of PTLD, particularly those who are EBV seronegative prior to transplant. Surveillance EBV-load monitoring to inform pre-emptive reduction of immunosuppression has contributed to the decrease in the incidence of PTLD in SOT recipients. The use of the anti-CD20 antibody, rituximab, as a therapeutic agent is increasing, with anecdotal reports of positive outcomes. However, experience to date suggests that the use of this agent may not prevent recurrence of the tumor or improve cell-mediated immune responses to EBV. Future investigation of EBV-specific T-cell responses as an adjunct to monitoring, and the adoptive transfer of EBV-specific cytotoxic T lymphocytes appear likely in future attempts as a means to limit the consequences of EBV infection in the SOT population.

Comparison of Two Techniques of Arterial Anastomosis During Adult Cadaveric Liver Transplantation

Arterial complications are a major source of morbidity and mortality after orthotopic liver transplantation (OLT). The incidence of hepatic artery thrombosis (HAT) ranges from 1.6% to 8%, with a mortality rate that ranges from 11% to 35%. We have described herein a technique of arterial anastomosis aiming to perform the anastomosis as straight as possible to avoid any kinking, redundancy, or malposition of the artery when the liver is released in its final position. We compared this technique with the traditional technique of arterial anastomosis using an aortic Carrel patch, namely, 198 OLT (group A) with the traditional technique and 117 OLT (group B) with the modified technique. An aorto-hepatic bypass was necessary in 25% of the cases in group A and in 21% of the cases in group B (P = .33). Vascular anomalies were present in 20% of cases in group A and in 27.5% in group B (P = .14). Fourteen cases (7%) of HAT developed in group A versus 0 cases in group B (P = .003). In group B, we experienced 2 (1.7%) late arterial stenoses that were successfully treated using percutaneous transluminal angioplasty. The 14 cases of HAT occurring in group A were successfully managed using immediate surgical revascularization with graft salvage in 6 cases (43%), whereas the remaining 8 cases needed urgent retransplantation. We suggest that a technique of arterial anastomosis aimed at avoiding kinking, redundancy, or malposition of the artery may be a viable option to reduce the risk of HAT after OLT.

Posttransplant Lymphoproliferative Disorders After Liver Transplantation: Analysis of Early and Late Cases in a 255 Patient Series

We reviewed the incidence and the impact of posttransplant lymphoproliferative disorders (PTLDs) on patient survival among a consecutive series of 255 patients. Five cases of PTLD were observed in adults: two cases were early (less than 1 year) and three cases, late lymphomas. The EBV positivity and the degree of immunosuppression were the main risk factors. We labeled cases as early or late according to whether the time elapsed from the transplant to the first clinical evidence of PTLD was less than 12 months. The median time from transplant to diagnosis of PTLD was 8 (early) and 108 (late) months. All cases were treated by reduction in immunosuppressive therapy with conventional chemotherapy and rituximab. The early cases with lymphoma located at the hepatic hilum died due to local complications (biliary sepsis and hemobilia), after an initial partial response to chemotherapy. The three patients with late cases are in remission after a mean follow-up of 23 months.

Significance of C4d staining in ABO-identical/compatible liver transplantation

Complement degradation product C4d has become an important marker of humoral or antibody-mediated rejection in renal and heart allograft biopsies. Although there have been several reports on the detection of C4d in liver allografts, the significance of C4d in liver transplantation and its relationship with humoral rejection are still not clear. We investigated the frequency and pattern of C4d staining in liver allograft biopsies with reference to preoperative lymphocyte crossmatch tests, which detect donor-reactive lymphocyte antibody. Survival rates at 5 years were 77% for crossmatch-negative patients and 53% for crossmatch-positive patients (P=0.009). In crossmatch-negative patients, reproducible positive staining was obtained in 28 of 86 (33%) biopsies taken within 90 days after transplantation and 33 of 96 (34%) biopsies 90 days or after transplantation. Most C4d staining was observed in the portal areas, and no clear correlation was observed between C4d positivity and histological diagnosis. In crossmatch-positive patients, 9 of 11 (82%) biopsies showed positivity for C4d. C4d stained perivenular areas as well as portal areas. Histology of crossmatch-positive patients included acute rejection and cholangitis, but did not include periportal changes that were seen in humoral rejection in ABO-incompatible liver transplantation. In summary, focal C4d deposition was seen in various types of liver allograft injury and had little clinical impact on crossmatch-negative patients, but extensive C4d staining in crossmatch-positive patients may be associated with humoral rejection and poor graft survival.

Rituximab therapy in malignant lymphoma

Rituximab is the first monoclonal antibody to have been registered for the treatment of B-cell lymphomas. Randomized studies have demonstrated its activity in follicular lymphoma (FL), mantle cell lymphoma and diffuse large B-cell lymphoma (DLBCL) in untreated or relapsing patients. Non-comparative studies have shown an activity in all other lymphomas. Because of its high activity and low toxicity ratio, rituximab has transformed the outcome of patients with B-cell lymphoma. A combination of rituximab plus chemotherapy, rituximab+cyclophosphamide+doxorubicin+vincristine+prednisolone (R-CHOP), has the highest efficacy ever described with any chemotherapy in DLBCL and FL. Some patients are refractory to rituximab but the precise mechanisms of this refractoriness are not understood.

Rituximab in the management of post-transplantation lymphoproliferative disorder after solid organ transplantation: proceed with caution

The introduction of single-agent rituximab has markedly changed the approach to therapy of patients with post-transplantation lymphoproliferative disorder (PTLD), but response to treatment varies substantially between patients. In the current report, we analyze long-term efficacy of single-agent rituximab in 60 patients and present factors predictive of progression-free and overall survival. Twelve months after completing first-line treatment, 34 of 60 patients (57%) had progressive disease, resulting in a median progression-free survival of 6.0 months at a median follow-up of 16.3 months. Using multivariate Cox regression analysis, the following factors were identified as significantly predictive of overall survival: age at diagnosis, performance status, lactate dehydrogenase (LDH), and time from transplantation to PTLD. Stage of disease and Epstein-Barr virus association of PTLD did not influence overall survival. LDH and time from transplantation to PTLD were also predictive of progression-free survival. The international prognostic index was shown to be of limited predictive value in these patients, but a PTLD-specific prognostic index separated low-, intermediate-, and high-risk patients with high significance: 2-year overall survival rates after first-line treatment with single-agent rituximab were 88, 50, and 0%, respectively. Thus, prognostic indices can be useful tools for prediction of treatment outcome and for the development of risk-adapted treatment strategies in patients with PTLD and may also provide the basis for interstudy comparisons.

Update in infectious diseases in liver transplant recipients

The prevention and management of bacterial, fungal, and viral infections are important components in the care of the liver transplant recipient. Although much progress has been made, challenges still remain. This article provides updates on the management of bilomas and peritonitis, the prevention and management of invasive Candida and Aspergillus infections, the prevention and management of cytomegalovirus disease, and the current status of liver transplantation in HIV-infected patients.

Liver transplantation: an update 2007

PURPOSE OF REVIEW

Recent attention in liver transplantation has focused on equity in organ allocation and management of posttransplant complications.

RECENT FINDINGS

Adoption of the model for end-stage liver disease for liver allocation has been successful in implementing a system based on medical urgency rather than waiting time. Refinements are being studied in improving the prediction of mortality and improving transplant benefit by balancing pretransplant mortality and posttransplant survival. Emerging literature is examining expansion of the current criteria for transplantation of hepatocellular carcinoma and the role of neoadjuvant therapy. Chronic renal dysfunction after liver transplantation is a source of considerable morbidity. Nephron-sparing immunosuppression regimens are emerging with encouraging results. Hepatitis C virus infection is difficult to differentiate histologically from rejection, although newer markers are being developed. Antiviral and immunosuppressive strategies for reducing the severity of hepatitis C virus recurrence are discussed. Alcohol relapse is common after liver transplant in alcoholic liver disease patients and can lead to worse outcomes.

SUMMARY

Organ allocation tends to evolve under the model for end-stage liver disease with a focus on maximizing transplant benefit. Hepatitis C virus, hepatocellular carcinoma, chronic renal dysfunction and alcohol relapse are major challenges, and continued research in these areas will undoubtedly lead to better outcomes for transplant recipients.

Presentation and early detection of post-transplant lymphoproliferative disorder after solid organ transplantation

Post-transplant lymphoproliferative disorder (PTLD) is a serious and still frequently observed complication of solid organ transplantation. Despite the recent introduction of anti B-cell monoclonal antibody therapy (rituximab) for treatment of PTLD, mortality rates remain high. Because PTLD often presents in a nonspecific way in clinically unsuspected patients, it is a major challenge to diagnose PTLD at an early stage. Epstein-Barr virus (EBV)-DNA load monitoring is a promising tool for the identification of patients at risk for PTLD development. However, there are some limitations of this method, and not all patients at risk for PTLD can be identified by EBV-DNA measurements alone. Therefore, it is of major importance to recognize early clinical signs and symptoms of PTLD. In this review, risk factors for PTLD development, disease presentation, and methods for early detection will be discussed. Special attention is given to allograft and digestive tract localization and the relation with time of onset of PTLD. The value and pitfalls of EBV-DNA load monitoring are discussed. In addition, because fluorodeoxyglucose (FDG)-positron emission tomography (PET) has shown to be a powerful tool for staging and response evaluation of malignant lymphoma, the role of FDG-PET for early diagnosis and staging of PTLD is addressed.

Utilization of extended donor criteria liver allograft: Is the elevated risk of failure independent of the model for end-stage liver disease score of the recipient?

BACKGROUND

The goal of this analysis was to determine if outcomes from the use of extended criteria donor (ECD) livers were dependent upon the Model for End-Stage Liver Disease (MELD) score of the recipient.

METHODS

The Organ Procurement and Transplantation Network (OPTN) database as of March 4, 2006 was used for the analysis. Data from 12,056 adult liver transplant (LTx) recipients between June 1, 2002 and June 30, 2005 was analyzed. The donor risk index (DRI) was calculated as previously reported. A DRI of > or =1.7 was classified as ECD. Relative risk (RR) estimates were derived from Cox regression models adjusted for DRI, recipient MELD, age, sex, ethnicity, diagnosis, and year of transplant.

RESULTS

Data from 2,873 grafts falling in the ECD category (23.8%) and their recipients were analyzed. Recipients with low MELD scores (<15) received the highest proportion of ECD livers (33%). ECD livers were associated with a significant increase in the RR of graft failure within each MELD category. However, this effect held within each of the three MELD categories.

CONCLUSION

The use of ECD grafts expands the organ pool at expense of increased RR of liver failure. Our analysis showed no significant interaction between DRI and MELD score of the recipient. The fact that there is no additional impact of ECD livers in recipients with high MELD scores suggests that this group of patients may benefit from this pool of grafts.

Induction therapy in renal transplantation : an overview of current developments

An overview of the past 10 years of clinical renal transplantation would include progress in the development of new induction protocols (non-depleting versus depleting monoclonal and polyclonal antibodies, plasmapheresis and intravenous immunoglobulins) designed to reduce the incidence and severity of rejection and adverse effects as well as improve long-term graft and patient survival. These modalities have been introduced primarily to reduce the incidence of acute rejection episodes leading to early graft loss, decrease the need for higher toxic doses of maintenance immunosuppressive drugs, such as calcineurin inhibitors, and possibly aid in the pursuit of the goal of achieving immunological tolerance and the avoidance of all long-term immunosuppressive therapy. What has resulted during the past 20 years as the use of induction agents has become more popular is the concurrent improvement in detection and treatment of acute and chronic infectious (primarily viral), and opportunistic and quasi-malignant disease accompanying the use of these agents and, therefore, their increase in popularity. However, the overall cost of therapy and the long-term results of protocols in which these agents have been used have not resulted in a definitive benefit thus far, because of the lack of sufficient numbers of defined randomised, long-term studies and the continuing introduction of newer protocols based on even more recent advances. The specific agents used for induction therapy to date, and the rationale for their introduction and mechanisms of action are discussed in this review.

Should antihepatitis B virus core positive or antihepatitis C virus core positive subjects be accepted as organ donors for liver transplantation?

Since the introduction of liver transplantation as a routine surgical procedure for the treatment of end-stage liver disease, there has been an increasing gap between the number of available grafts and the number of patients on the waiting list. This has led transplant centers to expand the donor pool by different means. One of them has been the introduction of living donor liver transplantation. Other strategies include using less than optimal allografts from deceased donors, the so-called marginal donors, which include the use of grafts from older subjects, livers with moderate amounts of steatosis, or from donors with markers of past or current infection with hepatitis viruses who have absent or minimal liver biochemical or histologic injury. In this review, we will focus on the current use of allografts from donors with antihepatitis B core antibody and/or antibodies against hepatitis C virus in cadaveric and living donor liver transplantation.

Immunosuppressive preconditioning or induction regimens : evidence to date

The success of solid organ transplantation has been directly related to the development of immunosuppressive drug therapies. Preconditioning or induction therapy was developed to reduce early immunological and nonimmunological renal injury, with the goal of increasing long-term graft survival. However, the routine induction of immunological tolerance to solid organ allograft is currently not achievable because of the morbidity and mortality related to the immunosuppressive regimens themselves. The different therapeutic preconditioning or induction agents and their associated effects on cellular rejection, graft survival outcomes and the need for multiagent post-transplant maintenance therapy are reviewed.

[Intensive care treatment following transplant surgery]

Transplant-related intensive care treatment after transplantation of visceral organs, in Germany traditionally headed by transplant surgeons, is an integral part of postoperative therapy after liver, pancreas, intestinal, and combined organ transplantation, i.e. pancreas-kidney, liver-kidney, and multivisceral transplantation. Apart from adjustment and monitoring of immunosuppressive therapy, as well as common intensive care issues such as cardiopulmonary disease and complications, the avoidance, early detection, and rigorous treatment of transplant-related problems are the focus of surgical intensive care treatment of transplant patients. In the following article, its role after visceral organ transplantation is described regarding the most frequent transplant-related complications such as technical failure, various kinds of infection, and graft failure with different etiologies.

Outcome of Imported Liver Allografts and Impact on Patient Access to Liver Transplantation

Liver allografts declined by local transplant centers are then offered regionally or nationally as imported grafts. Most of these grafts are declined because of poor donor quality. We retrospectively reviewed the medical records of patients who underwent liver transplantation between January 2004 and December 2005. There were 102 liver transplants in 98 recipients. They were divided into two groups: imported graft recipients (n = 37) and locally procured grafts recipients (n = 61). Eighty-six percent (32 of 37) of imported grafts were obtained from extended criteria donors defined as subjects treated with high doses of ionotropes with elevated liver enzymes, donor age over 70 years, macrosteatosis above 25%, positive hepatitis C or hepatitis B core antibody serology, systemic disease, history of cancer, hypernatremia, or with infection. The remaining grafts were declined due to unavailability of suitable recipients or social history. Recipient age and etiology of liver disease were similar for both groups. The mean MELD score was 22.1 +/- .9 among the imported graft recipients and 26.1 +/- 1 for the locally procured graft recipients (P < .01). There was no difference in blood loss or postoperative complications. Postoperative mean peak total bilirubin was similar in both groups. However, imported graft recipients had significantly higher mean peak AST (2436 +/- 282 vs 1380 +/- 165 U/L, P < .001) and ALT (1098 +/- 114 vs 803 +/- 87 U/L, P < .05). Primary graft nonfunction as well as 30 day and 1-year patient and graft survivals were similar for both groups. In conclusion, imported grafts can be transplanted in selected patients with outcomes comparable to locally procured grafts.

Use of extended criteria livers decreases wait time for liver transplantation without adversely impacting posttransplant survival

INTRODUCTION

The use of extended criteria donors (ECDs) could minimize shortage of suitable donor livers for transplantation. In 3 years, the aggressive use of ECD livers has reduced the wait list at our center from 257 to 30 patients with a median wait time of 18 days without using living donors. This study compares the graft/patient survival from standard (SD) and ECD for our transplant population between 2001 and 2005.

METHODS

Records of all adult liver transplant recipients over 4 years were reviewed (n = 571). ECD criteria included: age >59 years, BMI >34.9, maximum AST/ALT >500, maximum bilirubin >2.0, peak serum sodium >170, HBV/HCV/HTLV reactive, donation after cardiac death, cold ischemia time >12 hours, ICU stay >5 days, 3 or more pressors simultaneously, extensive alcohol abuse, cancer history (nonskin), active meningitis/bacteremia, or significant donor liver trauma. Outcomes included graft and patient survival at 90 days, 1 year, and 2 years.

RESULTS

Sixty-eight percent of recipients (n = 388) received ECD livers. Primary factors accounting for ECD-liver status included: elevated liver function tests (20%), hypernatremia (12.6%), and extensive alcohol abuse (11.4%). Graft survival was (SD, ECD): 90-day 91%, 88%; 1-year 84%, 80%; 2-year 78%, 77%; patient survival was: 90-day 93%, 90%; 1-year 87%, 82%; 2-year 83%, 79%. Kaplan-Meier survival analysis failed to demonstrate an overall difference in graft or patient survival at any time point. Only donor age >60 years was associated with decreased graft and patient survival.

CONCLUSIONS

Liver grafts from ECD can be used to dramatically reduce wait list time with outcomes comparable to those for SD without resorting to living donor liver transplantation.

Pseudoaneurysm of the Hepatic Artery Following Liver Transplantation

We report 12 cases of pseudoaneurysm hepatic artery (PA) among 825 liver transplantations (OLT) performed between January 1985 and December 2005. In the early period (1985 to 1995), the incidence was 2.6% and in the later period (1996 to 2005), 0.9%. Median time to onset was 39.5 days post-OLT (range 14 days to 5 years). Six patients presented with rupture into the peritoneum (n = 4) or gastrointestinal tract (n = 2), while five patients presented with gastrointestinal bleed due arteriobiliary fistulation with hemobilia. The twelfth PA was found incidentally during retransplantation. PAs were detected with radiological imaging (n = 4), exploratory laparotomy (n = 6), at autopsy (n = 1) or at retransplantation (n = 1). We performed immediate revascularization, after surgical excision was performed in three and endovascular embolization in one patient. In six patients hepatic artery ligation without revascularization was inevitable with subsequent successful retransplantation in four patients. No PA-specific treatment was attempted in two cases due to the poor prognosis or diagnostic ambiguity. In 10 cases microbial pathogens were cultured in the blood, subhepatic abscesses, or from the wall of the hepatic artery. A hepaticojejunostomy was performed for biliary reconstruction in six patients and two had a hepaticojejunostomy conversion due to biliary leak. Survival in the early period (1985 to 1995) was 14%, whereas during the later period (1996 to 2005), the survival increased to 100% with a 4.2-year median follow-up (range 7.4 months to 6.9 years). Infrequently PA complicates OLT, becoming evident primarily after rupture with hemoperitoneum or a gastrointestinal bleed. Early recognition with angiography is important but acute hemorrhage often requires immediate exploration with ligation of the PA, although surgical or endovascular exclusion of the PA followed by revascularization provides a feasible treatment option.

The emerging role of rituximab in organ transplantation

Long-term acceptance of solid organ allografts remains a challenge. While many acute rejection episodes can be treated, new mechanisms of allograft damage are now being defined especially in kidney transplantation. Unexpected clusters of CD20(+) cells have been discovered in renal biopsies performed for clinical rejection. C4d deposition is now routinely seen in refractory rejection. Despite the rapid introduction of new immunosuppressive agents in transplantation, the search for an efficacious anti-B-cell agent remains. With novel mechanisms of allograft damage now being defined, it is important to consider how an anti-B-cell agent might fit into an immunosuppressive regimen. Rituximab is a high-affinity CD20 specific antibody that depletes the B-cell compartment by inducing cellular apoptosis. Thus, it is a rational choice for therapy in transplantation to abrogate B-cell mediated events. In this review, we will discuss the mechanisms of action of rituximab, and its use in for a variety of indications in solid organ transplantation. There are emerging case reports that show that rituximab may be an effective agent to treat antibody-mediated rejection, and post-transplant lymphoproliferative disorder. Rituximab has been frequently cited as an important adjunct therapy in desensitization protocols for highly sensitized transplant recipients as well as recipients of ABO incompatible transplants. Rituximab demonstrates promise in this regard and warrants additional consideration in prospective clinical trials.

Drug insight: rituximab in renal disease and transplantation

Rituximab, a monoclonal antibody directed against the CD20 molecule found on pre-B cells and mature B cells (but not on plasma cells), was introduced in the late 1990s for the treatment of non-Hodgkin's lymphoma. Recently, this antibody has been used to treat autoimmune diseases, especially those associated with a prominent humoral component and with potentially pathogenic autoantibodies. Small cohort studies have indicated that rituximab could have an important role in the management of these disorders. Rituximab has also been utilized in the transplant setting, to diminish levels of alloreactive antibodies in highly sensitized patients, to manage ABO-incompatible transplants, and to treat rejection associated with B cells and antibodies. The exact mechanism by which rituximab exerts its effects in autoimmunity and transplantation remains unclear, as specific autoantibody or alloantibody levels often seem not to diminish in parallel with clinical improvement. A role for rituximab in depleting B cells and compromising their antigen-presenting function seems likely; rituximab might also inhibit T-cell activation. A synergistic effect has been noted in vitro following administration of corticosteroids to B-cell lines, with accentuation of B-cell cytotoxicity; this observation might be relevant to certain studies, as some regimens have utilized both agents simultaneously. This article reviews the current use of rituximab in renal disease and transplantation, and includes discussion of the drug's potential role in novel therapeutic protocols.

Case report of lamivudine-resistant hepatitis B virus infection post liver transplantation from a hepatitis B core antibody donor

The use of allografts from donors with hepatitis B core antibody in liver transplantation (LT) is associated with the risk of de novo hepatitis B virus (HBV) infection. Prophylaxis using hepatitis B Immune globulin (HBIg) and lamivudine alone or in combination has been reported. Yet, there are no standardized regimens and long-term efficacy is not known. We report a case of a patient who underwent LT for alcoholic liver disease who received an allograft from a donor with Hepatitis B core antibody. The patient had no previous exposure to HBV, was vaccinated against HBV, and had demonstrated Hepatitis B surface antibody present in serum before and 6 months after transplantation. Prophylaxis with short-term HBIg (1 week) and indefinite lamivudine was given. De novo HBV infection developed more than 3 years after LT with a lamivudine-resistant polymerase mutant containing the rtM204I and rtl180L/M mutations. We reviewed the risk of de novo post-LT HBV infection in recipients of livers from hepatitis B core antibody positive donors. High risk were HBV naïve recipients, moderate risk recipients had isolated hepatitis B surface antibody (anti-HBs) or hepatitis B core antibody (anti-HBc), while low-risk recipients had both anti-HBs and anti-HBc. We reviewed prophylaxis protocols reported in the literature and made recommendations for management.

Liver transplantation for inborn errors of liver metabolism

Liver transplantation brings complete recovery from end-stage liver disease, and full correction of liver based inborn errors of metabolism.

Valganciclovir: what is the status in solid organ transplantation?

Prophylactic drug therapy for cytomegalovirus disease in solid organ transplant recipients is effective and simple to implement, but it is associated with patient nonadherence and viral resistance. Recent data show that the efficacy and safety of oral ganciclovir and oral valganciclovir are similar. However, three large daily doses of oral ganciclovir are required, which is inconvenient, and viral resistance can develop to the drug. The single daily dose and lack of viral resistance are advantages of valganciclovir. This has become the primary agent for the prevention of cytomegalovirus disease. Current trials are underway to determine its effectiveness for treatment of cytomegalovirus disease, the optimal length of prophylaxis, and the safety and efficacy of a syrup formulation in children.

How to increase inflow in liver transplantation

Liver transplantation (LTx) has become the treatment of choice for selected cases of benign and malignant liver disease. Despite becoming increasingly safer in recent years this procedure still incurs several serious postoperative complications. The most significant surgical complications are related to surgical technique, particularly the reconstruction and/or anastomosis of the hepatic artery. Arterial hypoperfusion may lead to graft failure, sepsis, or ischemic biliary lesions. In this review we focus on the Achilles' heel of LTx: the hepatic artery. We provide transplant surgeons with an overview of the technical options that are available to increase arterial inflow and subsequently improve patient outcome. We exemplify some of the discussed techniques using a liver transplant case with an eventful postoperative course because of arterial complications.