Liver transplantation (2)

Basics and Art of Immunosuppression in Liver Transplantation

Liver transplantation is one of the most challenging areas in the medical field. Despite that, it has already been established as a standard treatment option, especially in decompensated cirrhosis and selected cases of hepatocellular carcinoma and acute liver failure. Complications due to graft rejection, including mortality and morbidity, have greatly improved over time due to better immunosuppressive agents and management protocols. Currently, immunosuppression in liver transplant patients makes use of the best possible combinations of effective agents to achieve optimal immunosuppression for long-term graft survival. Induction agents are no longer used routinely, and the aim is to provide minimal immunosuppression in the maintenance phase. Currently available immunosuppressive agents are mainly classified as biological and pharmacological agents. Though the protocols may vary among the centers and over time, the basics of effective use usually remain similar. Most protocols use the combination of multiple agents with different mechanisms of action to reduce the dose and minimize the side effects. Along with the improvement in operative and perioperative techniques, this art of immunosuppression has contributed to the recent progress made in the outcomes of liver transplants. In this review, we will discuss the various types of immunosuppressive agents currently in use, the different protocols of immunosuppression used, and the art of optimal use for achieving maximum immunosuppression without increasing toxicity. We will also discuss the practical aspects of various immunosuppression regimens, including drug monitoring, and briefly discuss the concepts of immunosuppression minimization and withdrawal.

Baseline Quantitative Hepatitis B Core Antibody Titer Is a Predictor for Hepatitis B Virus Infection Recurrence After Orthotopic Liver Transplantation

Objective

Hepatitis B virus (HBV) reinfection is a serious complication that arise in patients who undergo hepatitis B virus related liver transplantation. We aimed to use biomarkers to evaluate the HBV reinfection in patients after orthotopic liver transplantation.

Methods

Seventy-nine patients who underwent liver transplantation between 2009 and 2015 were enrolled, and levels of biomarkers were analyzed at different time points. Cox regression and receiver operating characteristic (ROC) curves of different markers at baseline were used to analyze sustained hepatitis B surface antigen (HBsAg) loss. The Kaplan-Meier method was used to compare the levels of the biomarkers.

Results

Among the 79 patients, 42 sustained HBsAg loss with a median time of 65.2 months (12.0-114.5, IQR 19.5) after liver transplantation and 37 patients exhibited HBsAg recurrence with a median time of 8.8 (0.47-59.53, IQR 19.47) months. In the ROC curve analysis, at baseline, 4.25 log₁₀ IU/mL qHBcAb and 2.82 log₁₀ IU/mL qHBsAg showed the maximum Youden’s index values with area under the curves (AUCs) of 0.685and 0.651, respectively. The Kaplan-Meier method indicated that qHBsAg and quantitative antibody against hepatitis B core antigen (qHBcAb) levels in the two groups were significantly different (p = 0.031 and 0.006, respectively). Furthermore, the Cox regression model confirmed the predictive ability of qHBcAb at baseline (AUC = 0.685).

Conclusion

Lower pretransplantation qHBcAb is associated with HBV infection. The baseline concentration of qHBcAb is a promising predictor for the recurrence of HBV in patients undergoing liver transplantation and can be used to guide antiviral treatment for HBV infection.

Efficacy and Safety of Hepatitis B Virus Vaccination Following Hepatitis B Immunoglobulin Withdrawal After Liver Transplantation

BACKGROUND

Hepatitis B immunoglobulin (HBIG) and oral nucleoside/nucleotide analogs have been the mainstay of hepatitis B virus (HBV) prophylaxis after liver transplantation. However, long-term HBIG administration could have disadvantages, such as an increase in medical costs and the development of mutant HBV strains. This study aimed to investigate the safety and efficacy of HBV vaccination after the withdrawal of HBIG after liver transplantation.

METHODS

This prospective open-label single-arm observational clinical trial enrolled 41 patients who underwent liver transplantation between 2010 and 2016 because of a condition related to chronic HBV infection. At the time of enrollment, all patients had taken entecavir and discontinued HBIG administration. When hepatitis B surface antibody titer was undetectable after the withdrawal of HBIG, a recombinant HBV vaccine was injected intramuscularly at month 0, 1, and 6.

RESULTS

After excluding 5 patients who dropped out and 2 patients who had a persistent hepatitis B surface antibody titer, 9 (26.5%) of 34 patients had a positive vaccination response. The median hepatitis B surface antibody titer at seroconversion was 86 (12-1000) IU/L, and those at the end of follow-up were 216 (30-1000) IU/L. No patients experienced HBV recurrence during the study period. Sex (female, odds ratio 32.91 [1.83-592.54], P = .018) and the dosing interval of HBIG before withdrawal (≥90 days, 16.21 [1.21-217.31], P = .035) were independent contributing factors for positive response to the vaccination.

CONCLUSION

HBV vaccination still deserves consideration as active immunoprophylaxis after liver transplantation because it could provide added immunity to nucleoside/nucleotide analogs monotherapy with excellent cost-effectiveness.

Risk factors for hepatitis B virus recurrence after living donor liver transplantation: A 22-year experience at a single center

The factors associated with hepatitis B virus (HBV) recurrence after living donor liver transplantation (LDLT) have not been fully clarified. The aim of this study was to determine the risk factors associated with HBV recurrence after LDLT. From January 1996 to December 2018, a total of 609 LDLT operations were performed at our center. A retrospective review was performed of 70 patients (male, n = 59; female, n = 11; median age = 54 years) who underwent LDLT for HBV-related liver disease. The virologic and biochemical data, tumor burden, antiviral and immunosuppressive therapy were evaluated and compared between the HBV recurrence and non-recurrence groups. Eleven of 70 patients (16%) developed post-LDLT HBV recurrence. The overall actuarial rates of HBV recurrence at 1, 3, 5, 10, and 20 years were 0%, 13%, 16.7%, 18.8%, and 18.8%, respectively. The median interval between LDLT and HBV recurrence was 57 months (range, 18-124 months). Based on the univariate and multivariate analyses, a serum HBV DNA level of ≥ 4 log copies/mL (hazard ratio [HR], 4.861; 95% confidence interval [95% CI], 1.172-20.165; P = 0.029), and hepatocellular carcinoma (HCC) beyond the Milan criteria (HR, 10.083; 95% CI, 2.749-36.982; P < 0.001) were independent risk factors for HBV recurrence after LDLT. In LDLT patients, high pre-LT HBV DNA levels and HCC beyond the Milan criteria were risk factors for HBV recurrence. With the current expansion of the LT criteria for HCC, we should remain cautious regarding the risk of HBV recurrence, particularly in these groups.

Understanding, predicting and achieving liver transplant tolerance: from bench to bedside

In the past 40 years, liver transplantation has evolved from a high-risk procedure to one that offers high success rates for reversal of liver dysfunction and excellent patient and graft survival. The liver is the most tolerogenic of transplanted organs; indeed, immunosuppressive therapy can be completely withdrawn without rejection of the graft in carefully selected, stable long-term liver recipients. However, in other recipients, chronic allograft injury, late graft failure and the adverse effects of anti-rejection therapy remain important obstacles to improved success. The liver has a unique composition of parenchymal and immune cells that regulate innate and adaptive immunity and that can promote antigen-specific tolerance. Although the mechanisms underlying liver transplant tolerance are not well understood, important insights have been gained into how the local microenvironment, hepatic immune cells and specific molecular pathways can promote donor-specific tolerance. These insights provide a basis for the identification of potential clinical biomarkers that might correlate with tolerance or rejection and for the development of novel therapeutic targets. Innovative approaches aimed at promoting immunosuppressive drug minimization or withdrawal include the adoptive transfer of donor-derived or recipient-derived regulatory immune cells to promote liver transplant tolerance. In this Review, we summarize and discuss these developments and their implications for liver transplantation.

The Immunological Basis of Liver Allograft Rejection

Liver allograft rejection remains a significant cause of morbidity and graft failure in liver transplant recipients. Rejection is caused by the recognition of non-self donor alloantigens by recipient T-cells. Antigen recognition results in proliferation and activation of T-cells in lymphoid tissue before migration to the allograft. Activated T-cells have a variety of effector mechanisms including direct T-cell mediated damage to bile ducts, endothelium and hepatocytes and indirect effects through cytokine production and recruitment of tissue-destructive inflammatory cells. These effects explain the histological appearances of typical acute T-cell mediated rejection. In addition, donor specific antibodies, most typically against HLA antigens, may give rise to antibody-mediated rejection causing damage to the allograft primarily through endothelial injury. However, as an immune-privileged site there are several mechanisms in the liver capable of overcoming rejection and promoting tolerance to the graft, particularly in the context of recruitment of regulatory T-cells and promotors of an immunosuppressive environment. Indeed, around 20% of transplant recipients can be successfully weaned from immunosuppression. Hence, the host immunological response to the liver allograft is best regarded as a balance between rejection-promoting and tolerance-promoting factors. Understanding this balance provides insight into potential mechanisms for novel anti-rejection therapies.

Control of Ischemia-Reperfusion Injury in Liver Transplantation: Potentials for Increasing the Donor Pool

Background

Organ shortage is a growing problem, with a rising number of organs being harvested from extended criteria donors, and this trend will further continue to increase as organ donors are getting older and have more comorbidities. Since this fact is immutable, efforts have been made to reduce the extent of ischemia-reperfusion injury (IRI) as well as of direct and indirect harvest-related graft injury which affects all organs in a more or less distinct way.

Methods

In liver transplantation (LT), the activation of Kupffer cells during organ reperfusion, thus provoking microcirculatory disturbances, hypoxia, and endothelial cell injury, is one of the key mechanisms causing graft dysfunction. Multiple approaches have been taken in order to find efficient preconditioning methods by pharmacological pretreatment, controlled induction of ischemia, controlled denervation of donor organs, and reconditioning with machine perfusion to prevent IRI, whereas marginal organs (i.e. steatotic grafts) are especially vulnerable.

Results

The above-mentioned approaches have been pursued in experimental and clinical settings. At this time point, however, there is not yet enough clinical evidence available to recommend any particular drug pretreatment or any other intervention for organ preconditioning prior to transplantation.

Conclusion

The multifactorial pathophysiology in the setting of IRI in LT requires a multimodal therapeutic approach with the integration of pharmacological and technical means being applied to the donor, the organ per se, and the recipient. Currently, there is no consensus on standardized pretreatment of donor organs in order to improve the transplant outcome.

Role of More Active Identification of Brain-Dead Cases in Increasing Organ Donation

OBJECTIVES

Organ donor shortage is a worldwide problem, resulting in 10% to 30% mortality rates for patients on wait lists for organ transplant. For brain-dead patients in Iran, it is mandatory for intensive care unit patients with Glasgow Coma Scale below 5/15 to be reported to an organ procurement unit. However, this process has not been functioning effectively. Here, we present the effects of changing the strategies on detecting brain-dead cases on the organ donor pool.

MATERIALS AND METHODS

From March 2015 to March 2016, we changed our strategy in active detection of brain-dead cases. Since March 2015, our newly established protocol for active detection of brain-dead cases includes the following changes: (1) instead of calling high-volume intensive care units 3 times per week, we switched to calling every day in the morning; (2) instead of calling low-volume intensive care units 1 time per week, we switched to calling 3 times per week; (3) we included intensive care units (cardiac and general), neurosurgery, and emergency departments, as well as nursing supervisor offices, in our call and visit lists; and (4) we increased visits to wards by our trained staff as inspectors.

RESULTS

From March 2015 to March 2016, the number of reported suspected brain-dead cases has increased from 224 to 460 per year, with proven brain death increasing from 180 to 306 cases. The actual number of donors has also increased, from 116 to 165 donations (53% increase) over 1 year.

CONCLUSIONS

More proactive strategies have had significant effects on brain-dead detection, resulting in significantly increased donor pools and organ donations. In countries with low cooperation of hospital staff, more proactive engagement in detecting brain-dead cases is a good solution to prevent loss of potential organ donors, with a final result of decreasing wait list mortality.

The relationship between HBcrAg and HBV reinfection in HBV related post-liver transplantation patients

BACKGROUND

Post-transplant hepatitis B virus (HBV) reinfection is one of the major problems facing patients who undergo HBV-related liver transplantation (LT). We analyzed the clinical impact of serum hepatitis B core-related antigen (HBcrAg) on HBV reinfection in post-LT patients with HBV-related liver diseases.

METHODS

Serum hepatitis B surface antigen (HBsAg), HBV DNA, and HBcrAg were measured over time in 32 post-LT patients. Twenty-one out of 32 patients had HCC at LT. The effects of HBcrAg, hepatocellular carcinoma (HCC) recurrence, and HBs gene mutation on HBV reinfection and withdrawal from hepatitis B immune globulin (HBIG) were analyzed.

RESULTS

Sixteen out of 32 patients (50 %) were positive for HBcrAg even though only six patients were thought to have experienced HBV reinfection based on reappearance of either HBV DNA or HBsAg during a median follow-up time of 75 months. Three of these six patients who became re-infected with HBV experienced HCC recurrence after LT. The HBV DNA reappearance rate was significantly higher in patients with HCC recurrence after LT (p < 0.001). Two HBV re-infected patients without HCC recurrence had HBs gene mutations G145R and G145A, respectively. Anti-HBs antibody development rate by HB vaccination was similar between HBcrAg-positive and negative patients (p = 0.325).

CONCLUSIONS

HBV reinfection is more common than is usually considered based on conventional measurement of HBsAg and HBV DNA. HCC recurrence and mutations in the HBV S gene were associated with HBV reinfection after LT.

Limitations of current liver transplant immunosuppressive regimens: renal considerations

BACKGROUND

The use of calcineurin inhibitor (CNI)-based immunosuppressive regimens following liver transplantation (LTx) has improved the outcomes of the recipients. However, CNI has nephrotoxicity and causes short- and long-term renal complications. The progressive structural changes can be irreversible in the long-term, leading to chronic kidney dysfunction. The present review was to evaluate the different strategies of CNI application to renal function in liver recipients.

DATA SOURCES

PubMed database was searched for relevant articles in English on the issue of immunosuppressive regimen and kidney injury that related to early minimization of CNI after LTx.

RESULTS

Total avoidance of CNI from post-LTx immunosuppressive regimens has been associated with unacceptable high rates of acute, steroid resistant rejections; late conversion from CNI to non-nephrotoxic immunosuppressant failed to recover renal function. Early CNI minimization and conversion to non-nephrotoxic immunosuppressant, although had no effect on patient survival rates, improved glomerular filtration rate. The combination of everolimus (a mammalian target of rapamycin inhibitor) and tacrolimus not only maintains immunosuppressive efficacy but also minimizes kidney injury.

CONCLUSIONS

Up to now, protocols entirely avoiding CNI have not passed the primary safety endpoint of patient and graft survival, as well as the FDA mandated endpoint of biopsy proven acute rejection. Thus, early CNI minimization after LTx is the most rational approach preserving post-transplant renal function.

Application of contrast-enhanced ultrasound after liver transplantation: Current status and perspectives

Liver transplantation is an effective treatment for patients with end-stage liver disease. Accurate imaging evaluation of the transplanted patient is critical for ensuring that the limited donor liver is functioning appropriately. Ultrasound contrast agents (UCAs), in combination with contrast-specific imaging techniques, are increasingly accepted in clinical use for the assessment of the hepatic vasculature, bile ducts and liver parenchyma in pre-, intra- and post-transplant patients. We describe UCAs, their technical requirements, the recommended clinical indications, image interpretation and the limitations for contrast-enhanced ultrasound applications in liver transplantation.

Risk factors for hepatitis B virus recurrence after living donor liver transplantation: A 17-year experience at a single center

AIM

The incidence of hepatitis B virus (HBV) recurrence after liver transplantation (LT) has been reduced by prophylaxis with hepatitis B immunoglobulin (HBIG) and nucleoside analogs, but the factors associated with HBV recurrence are unclear. The aim of this study was to determine the risk factors associated with HBV recurrence after living donor LT (LDLT).

METHODS

A retrospective review was performed for 45 patients (28 male and 17 female; median age, 54 years) who underwent LDLT for HBV-related liver disease and were followed up for at least 6 months between October 1996 and June 2013. The virological data, tumor burden, antiviral therapy and immunosuppressive therapy were evaluated and compared between the HBV recurrence ad non-recurrence groups.

RESULTS

Seven of the 45 patients (15.6%) developed post-LT HBV recurrence. The median interval between LDLT and HBV recurrence was 23.7 months (range, 0.8-35.9). Three of the seven patients (42.9%) developed recurrence after cessation of HBIG, and three (42.9%) were cases with hepatocellular carcinoma (HCC) recurrence after LDLT. The remaining case underwent transplantation from a donor with positive hepatitis B surface antigen. Based on the univariate and multivariate analyses, HBIG cessation (hazard ratio [HR], 20.17; 95% confidence interval [95% CI], 2.091-194.593; P = 0.009) and HCC recurrence (HR, 30.835; 95% CI, 3.132-303.593; P = 0.003) were independent risk factors for HBV recurrence after LDLT.

CONCLUSION

In LDLT patients, cessation of HBIG and HCC recurrence were risk factors associated with HBV recurrence, so careful monitoring for serological HBV markers is needed in patients with these factors.

Application of nucleoside analogues to liver transplant recipients with hepatitis B

Hepatitis B is a common yet serious infectious disease of the liver, affecting millions of people worldwide. Liver transplantation is the only possible treatment for those who advance to end-stage liver disease. Donors positive for hepatitis B virus (HBV) core antibody (HBcAb) have previously been considered unsuitable for transplants. However, those who test negative for the more serious hepatitis B surface antigen can now be used as liver donors, thereby reducing organ shortages. Remarkable improvements have been made in the treatment against HBV, most notably with the development of nucleoside analogues (NAs), which markedly lessen cirrhosis and reduce post-transplantation HBV recurrence. However, HBV recurrence still occurs in many patients following liver transplantation due to the development of drug resistance and poor compliance with therapy. Optimized prophylactic treatment with appropriate NA usage is crucial prior to liver transplantation, and undetectable HBV DNA at the time of transplantation should be achieved. NA-based and hepatitis B immune globulin-based treatment regimens can differ between patients depending on the patients’ condition, virus status, and presence of drug resistance. This review focuses on the current progress in applying NAs during the perioperative period of liver transplantation and the prophylactic strategies using NAs to prevent de novo HBV infection in recipients of HBcAb-positive liver grafts.

From immunosuppression to tolerance

The past three decades have seen liver transplantation becoming a major therapeutic approach in the management of end-stage liver diseases. This is due to the dramatic improvement in survival after liver transplantation as a consequence of the improvement of surgical and anaesthetic techniques, of post-transplant medico-surgical management and of prevention of disease recurrence and other post-transplant complications. Improved use of post-transplant immunosuppression to prevent acute and chronic rejection is a major factor in these improved results. The liver has been shown to be more tolerogenic than other organs, and matching of donor and recipients is mainly limited to ABO blood group compatibility. However, long-term immunosuppression is required to avoid severe acute and chronic rejection and graft loss. With the current immunosuppression protocols, the risk of acute rejection requiring additional therapy is 10-40% and the risk of chronic rejection is below 5%. However, the development of histological lesions in the graft in long-term survivors suggest atypical forms of graft rejection may develop as a consequence of under-immunosuppression. The backbone of immunosuppression remains calcineurin inhibitors (CNI) mostly in association with steroids in the short-term and mycophenolate mofetil or mTOR inhibitors (everolimus). The occurrence of post-transplant complications related to the immunosuppressive therapy has led to the development of new protocols aimed at protecting renal function and preventing the development of de novo cancer and of dysmetabolic syndrome. However, there is no new class of immunosuppressive drugs in the pipeline able to replace current protocols in the near future. The aim of a full immune tolerance of the graft is rarely achieved since only 20% of selected patients can be weaned successfully off immunosuppression. In the future, immunosuppression will probably be more case oriented aiming to protect the graft from rejection and at reducing the risk of disease recurrence and complications related to immunosuppressive therapy. Such approaches will include strategies aiming to promote stable long-term immunological tolerance of the liver graft.

Pre- and postoperative nutritional assessment and health-related quality of life in recipients of living donor liver transplantation

AIM

The nutritional state of living donor liver transplantation (LDLT) recipients is one of the most important factors affecting postoperative outcome. Although the assessment of health-related quality of life (HRQOL) is of increasing importance, few studies have examined this in conjunction with LDLT recipient nutritional state.

METHODS

Ten LDLT recipients with end-stage liver disease were recruited for this study. Measurements of energy expenditure, anthropometrics and laboratory data were performed before and 1, 6 and 12-24 months after LDLT. HRQOL was measured by using the 36-item Short-Form (SF-36) before and 1, 3, 6 and 12-24 months after LDLT.

RESULTS

The preoperative value of non-protein respiratory quotient (npRQ) was 0.796 ± 0.026 and it increased significantly after the operation. Serum non-esterified fatty acid (NEFA) levels were high in the preoperative state, but had significantly decreased 1 month after the operation. A negative correlation between npRQ and NEFA was observed throughout the study period. Cholinesterase and albumin levels improved to normal levels within 6 and 12-24 months, respectively. The recovery of the physical component summary of the SF-36 was observed after the improvement of all domains of laboratory data and energy metabolism based on the nutritional state.

CONCLUSION

This study demonstrated that the recovery of metabolic function, laboratory data and HRQOL in LDLT recipients are variable, and it took more than 6 months to normalize the liver protein synthetic capacity and physical HRQOL score periods. Therefore, long-term nutritional support is required in LDLT recipients.

The role of everolimus in liver transplantation

During the last 5 decades, liver transplantation has witnessed rapid development in terms of both technical and pharmacologic advances. Since their discovery, calcineurin inhibitors (CNIs) have remained the standard of care for immunosuppression therapy in liver transplantation, improving both patient and graft survival. However, adverse events, particularly posttransplant nephrotoxicity, associated with long-term CNI use have necessitated the development of alternate treatment approaches. These include combination therapy with a CNI and the inosine monophosphate dehydrogenase inhibitor mycophenolic acid and use of mammalian target of rapamycin (mTOR) inhibitors. Everolimus, a 40-O-(2-hydroxyethyl) derivative of mTOR inhibitor sirolimus, has a distinct pharmacokinetic profile. Several studies have assessed the role of everolimus in liver transplant recipients in combination with CNI reduction or as a CNI withdrawal strategy. The efficacy of everolimus-based immunosuppressive therapy has been demonstrated in both de novo and maintenance liver transplant recipients. A pivotal study in 719 de novo liver transplant recipients formed the basis of the recent approval of everolimus in combination with steroids and reduced-dose tacrolimus in liver transplantation. In this study, everolimus introduced at 30 days posttransplantation in combination with reduced-dose tacrolimus (exposure reduced by 39%) showed comparable efficacy (composite efficacy failure rate of treated biopsy-proven acute rejection, graft loss, or death) and achieved superior renal function as early as month 1 and maintained it over 2 years versus standard exposure tacrolimus. This review provides an overview of the efficacy and safety of everolimus-based regimens in liver transplantation in the de novo and maintenance settings, as well as in special populations such as patients with hepatocellular carcinoma recurrence, hepatitis C virus-positive patients, and pediatric transplant recipients. We also provide an overview of ongoing studies and discuss potential expansion of the role for everolimus in these settings.

Early allograft dysfunction is associated with excess resource utilization after liver transplantation

BACKGROUND

There are limited data on length of stay (LOS) following liver transplantation (LT), yet this is an important health services metric that directly correlates with early post-LT health care costs. The primary objective of this study was to examine the relationship between early allograft dysfunction (EAD) and LOS after LT. The secondary objective was to identify additional recipient, donor, and operative factors associated with LOS.

METHODS

Adult patients undergoing primary LT over a 32-month period were prospectively examined at a single center. Subjects fulfilling standard criteria for EAD were compared with those not meeting the definition. Variables associated with increased LOS on ordinal logistic regression were identified.

RESULTS

Subjects with EAD had longer mean hospital LOS than those without (42.5 ± 38.9 days vs 27.4 ± 31 days; P = .003). Subjects with EAD also had longer mean intensive care LOS (8.61 ± 10.28 days vs 5.45 ± 11.6 days; P = .048). Additional factors significantly associated with LOS included Model for End-Stage Liver Disease (MELD) score, recipient location before LT, and postoperative surgical complications.

CONCLUSIONS

EAD is associated with longer hospitalization after LT. MELD score, preoperative recipient location, and postoperative complications were significantly associated with LOS. From a cost-containment perspective, these findings have implications on resource allocation.

Prophylaxis of hepatitis B infection in solid organ transplant recipients

Rates of transmission of hepatitis B virus (HBV) infection from organ donors with HBV markers to recipients along with reactivation of HBV during immunosuppression following transplantation have fallen significantly with the advent of hepatitis B immune globulin (HBIg) and effective antiviral therapy. Although the availability of potent antiviral agents and HBIg has highly impacted the survival rate of HBV-infected patients after transplantation, the high cost associated with this practice represents a major financial burden. The availability of potent antivirals with high genetic barrier to resistance and minimal side effects have made it possible to recommend an HBIg-free prophylactic regimen in selected patients with low viral burden prior to transplant. Significant developments over the last two decades in the understanding and treatment of HBV infection necessitate a re-appraisal of the guidelines for prophylaxis of HBV infection in solid organ transplant recipients.

Endoscopic approach to the post liver transplant patient

Biliary complications occur after liver transplantation. These complications can be effectively and safely managed using endoscopic approaches and can prevent unnecessary and potentially morbid surgery.

Hollow fiber bioartificial liver utilizing collagen-entrapped porcine hepatocyte spheroids

A xenogeneic hollow fiber bioreactor utilizing collagen-entrapped dispersed hepatocytes has been developed as an extracorporeal bioartificial liver (BAL) for potential treatment of acute human fulminant hepatitis. Prolonged viability, enhanced liver-specific functions, and differentiated state have been observed in primary porcine hepatocytes cultivated as spheroids compared to dispersed hepatocytes plated on a monolayer. Entrapment of spheroids into the BAL can potentially improve performance over the existing device. Therefore, studies were conducted to evaluate the feasibility of utilizing spheroids as the functionally active component of our hybrid device. Confocal microscopy indicated high viability of spheroids entrapped into cylindrical collagen gel. Entrapment of spheroids alone into collagen gel showed reduced ability to contract collagen gel. By mixing spheroids with dispersed cells, the extent of collagen gel contraction was increased. Hepatocyte spheroids collagen-entrapped into BAL devices were maintained for over 9 days. Assessment of albumin synthesis and ureagenesis within a spheroid-entrapment BAL indicated higher or at least as high activity on a per-cell basis compared to a dispersed hepatocyte-entrapment BAL device. Clearance of 4-methylumbelliferone to its glucuronide was detected throughout the culture period as a marker of phase II conjugation activity. A spheroid-entrapment bioartificial liver warrants further studies for potential human therapy. (c) 1996 John Wiley & Sons, Inc.

Development of a bioartificial liver employing xenogeneic hepatocytes

Liver failure is a major cause of mortality. A bioartificial liver (BAL) employing isolated hepatocytes can potentially provide temporary support for liver failure patients. We have developed a bioartificial liver by entrapping hepatocytes in collagen loaded in the luminal side of a hollow fiber bioreactor. In the first phase of development, liver-specific metabolic activities of biosynthesis, biotransformation and conjugation were demonstrated. Subsequently anhepatic rabbits were used to show that rat hepatocytes continued to function after the BAL was linked to the test animal. For scale-up studies, a canine liver failure model was developed using D-galactosamine overdose. In order to secure a sufficient number of hepatocytes for large animal treatment, a collagenase perfusion protocol was established for harvesting porcine hepatocytes at high yield and viability. An instrumented bioreactor system, which included dissolved oxygen measurement, pH control, flow rate control, an oxygenator and two hollow fiber bioreactors in series, was used for these studies. An improved survival of dogs treated with the BAL was shown over the controls. In anticipated clinical applications, it is desirable to have the liver-specific activities in the BAL as high as possible. To that end, the possibility of employing hepatocyte spheroids was explored. These self-assembled spheroids formed from monolayer culture exhibited higher liver-specific functions and remained viable longer than hepatocytes in a monolayer. To ease the surface requirement for large-scale preparation of hepatocyte spheroids, we succeeded in inducing spheroid formation in stirred tank bioreactors for both rat and porcine hepatocytes. These spheroids formed in stirred tanks were shown to be morphologically and functionally indistinguishable from those formed from a monolayer. Collagen entrapment of these spheroids resulted in sustaining their liver-specific functions at higher levels even longer than those of spheroids maintained in suspension. For use in the BAL, a mixture of spheroids and dispersed hepatocytes was used to ensure a proper degree of collagen gel contraction. This mixture of spheroids and dispersed cells entrapped in the BAL was shown to sustain the high level of liver-specific functions. The possibility of employing such a BAL for improved clinical performance warrants further investigations.

Mechanisms of tumor necrosis factor-alpha and interleukin-6 induction during human liver transplantation

In human orthotopic liver transplantation (LTX) intraoperative elevations of TNF-α (> 100 pg/ml) and IL-6 (>800 pg/ml) have been found to correlate with early post-operative rejections and infections respectively. In this study the possible mechanism responsible for the induction of these cytokines has been investigated during liver allografting in 38 recipients. Intraoperative elevations of TNF-α (> 100 pg/ml) were detected in the majority of pre-transplant endotoxin positive recipients (8/12, > 10 endotoxin units/ml), the patients turning endotoxin positive until the end of grafting (3/5), and in a subgroup (6/21 patients), apparently endotoxin negative for the whole operation. Therefore endotoxin (ET) seems to stimulate release of TNF-α in approximately 50% of the patients, whereas sensitized Kupffer graft cells or immediate allograft reactivity of the host are likely to account for the remaining TNF-α positive cases. Elevations of IL-6 > 800 pg/ml) were found in approximately 50% of the TNF-α positive cases, indicating partially independent regulatory pathways for IL-6 induction in the TNF-α negative patients. In agreement with a previous study, 11/13 (85%) of the intraoperative TNF-α positive recipients rejected their grafts within the first 10 days post-operatively. These data demonstrate that ET/infection associated as well as ET independent/reperfusion associated intraoperative TNF-α elevations, promote the initiation of allograft rejection in human liver transplantation. The transient and low endotoxaemia caused by the liver grafting procedure performed without veno-venous bypass seems to be of minor importance in the intraoperative induction of TNF-α.

Exclusions and deaths on the liver transplant waiting list

OBJECTIVE

To analyze the characteristiscs, evolution and survival of patients included on the waiting list (WL) for liver transplantation (OLT).

PATIENTS AND METHODS

Between February 2002 and April 2009, 254 patients were included on WL to receive a first graft. Two hundred twenty-two patients (87.4%) were transplanted (group T); 7 (2.8%) died on the WL and 25 (9.8%) were excluded, namely, 13 (52%) due to improvement (group IE) and 12, for other reasons (group OE). Data collected prospectively were analyzed retrospectively.

RESULTS

Indications for transplant were cirrhosis (58%), hepatocellular carcinoma (HCC; 29%) and other etiologies (13%.) Average time on the WL was 60.3 +/- 62.9 days. Significant differences were not observed among the groups with respect to age, gender, or indication for OLT. The probability for exclusion due to progression and/or death was not significantly greater among patients included for HCC than for other reasons (P = .6). Survivals at 1, 3, and 5 years after WL inclusion were 81.2%, 73.3%, and 68.6%, respectively, in the whole series; and 85,4%, 76,9%, and 71.7% in group T. All group OE patients died before the first year, while group IE showed a survival of 100%, 91.7% and 91.7% at 1, 3, and 5 years, respectively. Survival was not different between groups T and IE (P = .03), but was lower in group OE than in groups T or IE (P < .001).

CONCLUSION

The list mortality rate in our series was low, probably in relation to the short waiting time. The rate of exclusion from WL was 10%. Patient with hepatocellular carcinoma were not at an increased risk of WL exclusion. Patients excluded due to improvement displayed excellent survivals during the 5 years following exclusion.

Recurrence of hepatocellular carcinoma and hepatitis B reinfection in hepatitis B surface antigen-positive patients after liver transplantation

Hepatitis B virus (HBV) reinfection and recurrence of hepatocellular carcinoma (HCC) after orthotopic liver transplantation (OLT) are associated with increased graft failure and reduced patient survival. We evaluated the effects of both HCC recurrence and HBV reinfection on the long-term survival of these patients after OLT. One hundred seventy-five patients underwent OLT for HBV-related liver diseases and were the subjects of this retrospective study. We assessed risk factors for HBV reinfection, HCC recurrence, and survival post-OLT using univariate and multivariate analyses. During a mean follow-up of 43.0 +/- 42.0 months, 88 of 175 (50.3%) patients transplanted for HBV-related liver disease had HCC prior to OLT. Thirteen (14.8%) of these patients had HCC recurrence after OLT. The mean time for recurrence of HCC was 26.1 +/- 31.9 months. Twelve of 175 (6.9%) patients developed HBV reinfection after liver transplantation. The mean time for HBV reinfection was 28.7 +/- 26.4 months. Ten of these 12 (83.3%) patients had HCC prior to OLT, and 5 (50%) developed recurrence of HCC. On multivariate analyses, pre-OLT HCC and recurrence of HCC post-OLT were significantly associated with HBV reinfection after transplantation (P = 0.031 and P < 0.001, respectively). HCC recurrence after OLT was associated with lymphovascular invasion (P < 0.001) and post-OLT chemotherapy (P < or = 0.001). The 3- and 5-year survival rates were significantly decreased in patients with HBV reinfection (P = 0.007) and in patients with HCC recurrence after OLT (P = 0.03). In conclusion, pre-OLT HCC and HCC recurrence after transplantation were associated with HBV reinfection and with decreased patient survival. Hepatitis B immunoglobulin and antiviral therapy was only partially effective in preventing HBV reinfection in patients with HCC recurrence.

Contrast-enhanced ultrasound with SonoVue in the evaluation of postoperative complications in pediatric liver transplant recipients

PURPOSE

To evaluate the utility of contrast-enhanced sonography in the study of pediatric liver transplant recipients and its potential impact in reducing the need for invasive diagnostic procedures.

MATERIALS AND METHODS

From October 2002 to December 2003 we performed routine color Doppler ultrasound and contrast-enhanced ultrasound studies on 30 pediatric patients who had undergone liver transplantation. Findings indicative of complications were confirmed with invasive studies (angiography, computed tomography, and PTC).

RESULTS

Contrast-enhanced sonography correctly identified four of the five cases of hepatic artery thrombosis and all those involving the portal (n = 6) and hepatic vein (n = 3) thrombosis. It failed to identify one case of hepatic artery thrombosis characterized by collateral circulation arising from the phrenic artery and the single case of hepatic artery stenosis. The latter was more evident on color Doppler, which revealed a typical tardus parvus waveform. The use of contrast offered no significant advantages in the study of biliary complications although it did provide better visualization of bile leaks.

CONCLUSIONS

Contrast-enhanced sonography improves diagnostic confidence and reduces the need for more invasive imaging studies in the postoperative follow-up of pediatric liver transplant recipients.

[The prophylaxis against post-liver-transplant hepatitis B re-infection]

OBJECTIVE

To review the prophylaxis against post-liver transplantation hepatitis B reinfection with anti-hepatitis B immunoglobulin and nucleoside analogues.

METHOD

A bibliographic search was carried out using Pubmed, entering the following key words: hepatitis B and liver transplantation and (hepatitis B hyperimmune globulin and lamivudine and adefovir dipivoxil) up to June 2006. The initial search was filtered using the terms clinical trial, randomized clinical trial and review. The data contained in selected studies were reviewed.

RESULTS

A total of 53 works were found. Prophylaxis with anti-HB immunoglobulin and lamivudine is the best strategy for avoiding recurrence of the hepatitis B virus in patients undergoing hepatic transplants; achieving very low reinfection rates (0-10%) with follow up periods of between 1-5 years. There is a great degree of variability (dose, duration and method of HBIg administration) in the prophylactic protocols reviewed. The use of low doses of anti-HB immunoglobulin (administered intravenously followed by intramuscular administration, or administered intramuscularly from the anhepatic stage), and lamivudine in patients who receive transplants with a low risk of recurrence, shows prophylactic efficacy comparable to the use of high doses of anti-HB immunoglobulin. Furthermore, it implies a considerable reduction in costs.

CONCLUSIONS

The availability of suitably designed clinical trials is required to design a more cost-effective protocol and reduce variability.

Cirrhotic cardiomyopathy

Cirrhotic cardiomyopathy is the term used to describe a constellation of features indicative of abnormal heart structure and function in patients with cirrhosis. These include systolic and diastolic dysfunction, electrophysiological changes, and macroscopic and microscopic structural changes. The prevalence of cirrhotic cardiomyopathy remains unknown at present, mostly because the disease is generally latent and shows itself when the patient is subjected to stress such as exercise, drugs, hemorrhage and surgery. The main clinical features of cirrhotic cardiomyopathy include baseline increased cardiac output, attenuated systolic contraction or diastolic relaxation in response to physiologic, pharmacologic and surgical stress, and electrical conductance abnormalities (prolonged QT interval). In the majority of cases, diastolic dysfunction precedes systolic dysfunction, which tends to manifest only under conditions of stress. Generally, cirrhotic cardiomyopathy with overt severe heart failure is rare. Major stresses on the cardiovascular system such as liver transplantation, infections and insertion of transjugular intrahepatic portosystemic stent-shunts (TIPS) can unmask the presence of cirrhotic cardiomyopathy and thereby convert latent to overt heart failure. Cirrhotic cardiomyopathy may also contribute to the pathogenesis of hepatorenal syndrome. Pathogenic mechanisms of cirrhotic cardiomyopathy are multiple and include abnormal membrane biophysical characteristics, impaired β-adrenergic receptor signal transduction and increased activity of negative-inotropic pathways mediated by cGMP. Diagnosis and differential diagnosis require a careful assessment of patient history probing for excessive alcohol, physical examination for signs of hypertension such as retinal vascular changes, and appropriate diagnostic tests such as exercise stress electrocardiography, nuclear heart scans and coronary angiography. Current management recommendations include empirical, nonspecific and mainly supportive measures. The exact prognosis remains unclear. The extent of cirrhotic cardiomyopathy generally correlates to the degree of liver insufficiency. Reversibility is possible (either pharmacological or after liver transplantation), but further studies are needed.

Elective Transjugular Intrahepatic Portosystemic Shunt Creation for Portal Decompression in the Immediate Pretransplantation Period in Adult Living Related Liver Transplant Recipient Candidates: Preliminary Results

PURPOSE

To evaluate (i) the efficacy of purposeful creation of transjugular intrahepatic portosystemic shunts (TIPS) before transplantation to optimize potential living related liver transplantation (LRLTx) and (ii) the efficacy of TIPS creation in this setting in reducing perioperative resource utilization.

MATERIALS AND METHODS

Retrospective review was performed of the records of patients who underwent adult LRLTx with or without preoperative TIPS creation from October 2003 through April 2005. Patients were evaluated for preoperative parameters (Child-Pugh class, Model for End-stage Liver Disease score, Acute Physiology and Chronic Health Evaluation [APACHE] II score, and coagulation parameters), intraoperative parameters (blood transfusion requirements and operative time), and postoperative parameters (intensive care unit stay, hospital stay, and 30-day repeat operation and mortality rates). Comparison between the two treatment groups was made with the Mann-Whitney U test. Within the TIPS group, comparison of blood transfusion requirements was performed by one-way analysis of variance based on the degree of portosystemic gradient reduction after TIPS creation.

RESULTS

Sixteen patients were included in the TIPS group, and 12 patients were included in the group without TIPS. Median time between TIPS and transplantation was 2 days. There was no statistical difference in the preoperative, intraoperative, and postoperative parameters between groups except for the APACHE II score (P<.002), which was higher in the TIPS group. Despite this, the outcome and postoperative hospital resource utilization were similar between groups. Intraoperative blood transfusion based on the degree of portosystemic gradient reduction after TIPS creation was not significantly different between groups.

CONCLUSIONS

Newly created TIPS do not interfere with the intraoperative technical and perioperative clinical aspects of adult LRLTx. Preoperative TIPS creation before transplantation may reduce the postoperative morbidity and mortality seen in liver transplant recipients who have a greater APACHE II score at the outset of treatment.

Deaths on the liver transplant waiting list: an analysis of competing risks

The usual method of estimating survival probabilities, namely the Kaplan-Meier method, is suboptimal in the analysis of deaths on the transplant waiting list. Death, transplantation, and withdrawal from list must all be considered. In this analysis, we applied the competing risk analysis method, which allows evaluating these end points individually and simultaneously, to compare the risk of waiting list death across era, blood types, liver disease diagnosis, and severity (Model for End-stage Liver Disease; MELD). Of 861 patients registered on the waiting list at Mayo Clinic Rochester between 1990 and 1999, 657 (76%) patients underwent transplantation, 82 (10%) died while waiting, 41 (5%) withdrew from the list, and 81 (9%) patients were still waiting as of February 2002. The risk of death at 3 years was 10% by the competing risk analysis. During the study period, the median time to transplantation increased from 45 to 517 days. In univariate analyses, there was no significant difference in the risk of death by era of listing (P = .25) or blood type (P = .31), whereas the risk of death was significantly higher in patients with alcohol-induced liver disease and those with higher MELD score (P < .01). A multivariable analysis showed that after adjusting for MELD, blood type, and diagnosis, patients listed in the latter era had higher mortality. In conclusion, the competing risk analysis method is useful in estimating the risk of death among patients awaiting liver transplantation.

Cyclosporin-induced gingival overgrowth in children

Cyclosporin is a potent immunosuppressant drug commonly used to prevent organ transplant rejection. In recent years, there has been a widening of its therapeutic use and an increase in the number of patients undergoing transplantation. Gingival overgrowth is one of several oral side-effects of cyclosporin, with a quoted prevalence of between 8% and 100%. There is continued debate over the factors which modify the degree of overgrowth, including individual sensitivity, age, dose of drug, duration of drug therapy and the presence of dental plaque. The exact mechanism of gingival overgrowth is still being debated, but appears to be caused by a combination of the proliferation of fibroblasts within the gingival tissue, an increase in the deposition of collagen and extracellular matrix, and a decrease in phagocytosis with a net gain in gingival tissue mass. A number of treatment options are utilized in the treatment of gingival overgrowth, including CO2 laser surgery, improved oral hygiene, the use of antibiotics such as metronidazole and azithromycin, and surgical intervention. In the clinical application of cyclosporin, there is little correlation between cyclosporin dose, serum trough levels and total exposure to the drug, making it difficult to achieve the desired therapeutic response. These problems were previously further complicated by the variability of absorption of the drug via the gastrointestinal tract. The original cyclosporin formulation, Sandimmune, was replaced by a new formulation, Neoral, which has a more reliable absorption, and gives a closer correlation between trough concentration levels and individual bioavailability. There is a conflict of opinion over whether or not the side-effect profile of Neoral varies from its precursor Sandimmune. It has yet to be seen whether the increased bioavailability of Neoral will result in an increased severity and prevalence of gingival overgrowth. An alternative immunosuppressant drug, tacrolimus, which is a macrolide antibiotic with a different side-effect profile, has emerged as a substitute for cyclosporin in organ transplantation. However, there have been conflicting reports of its side-effects and its capacity to cause gingival overgrowth.

Synergistic value of fibrinolysis and hypothermic aerobic preservation with oxygen in the protection of livers from non-heart-beating donors: an experimental model

The chronic organ shortage has led to the reconsideration of marginal donor pools such as non-heart-beating donors (NHBD). The use of these livers is limited due to their minimal tolerance for cold preservation. The aim of this study was to examine the combination of two different therapeutic strategies for the preservation of livers from NHBD. The livers of male Wistar rats were harvested after the induction of cardiac arrest via phrenotomy (30, 90 minutes). Livers were perfused with 10 mL of UW solution (UW), followed by hypothermic preservation with or without insufflation of gaseous oxygen (O2). In one group a fibrinolytic preflush (10 mL of Ringer's containing 7500 IU of streptokinase) was performed with subsequent preservation with O2 (O2+SK). After storage (24 h/4 degrees C/UW) livers were reperfused in vitro. Livers retrieved from heart beating donors served as controls. The results showed that even after only 30 minutes of warm ischemia livers displayed a serious disturbance in vascular perfusion (portal venous pressure, PVP = 7.4 +/- 0.2* versus control: 4.1 +/- 0.5 mmHg), associated with a more than 10-fold increase in enzyme release (ALT: 26819 +/- 513* versus control 683 +/- 152 mU/g/L), which was consistent with a significant depression in bile synthesis (1.21 +/- 0.35* versus 19.36 +/- 2.16 microL/g/45 min). However, these impairments could be prevented with O2. Even after 90 minutes of WI, the function was significant better using aerobic preservation (ALT: 3204 +/- 549 mU/g/L). With a supplementary fibrinolytic preflush, we effectively preserved livers up to 90 minutes of WI with results comparable to livers from heart beating donors with no WI (ALT: 1623 +/- 432 mU/g/L). The combination of these two techniques represents a new therapeutic approach for livers with extended or unclear WI periods in non-heart-beating donors (*P <.05 versus control).

Liver Transplantation for Children: Red Cross Children's Hospital Experience

BACKGROUND

The liver transplant program for infants and children at the Red Cross Children's Memorial Hospital is the only established pediatric service in sub-Saharan Africa. Since 1985, 250 infants and children have been assessed and 155 accepted for transplantation.

METHODS

Since 1987, 76 children (range 6 months to 14 years) have had 79 liver transplants, with biliary atresia being the most frequent diagnosis. The indications for transplantation include biliary atresia (n = 44), metabolic (n = 7), fulminant hepatic failure (n = 10), redo transplants (n = 3), and other (n = 15). Three combined liver/kidney transplants have been performed. Forty-nine were reduced-size transplants with donor: recipient weight ratios ranging from 2:1 to 11:1, and 29 children weighed < 10 kg.

RESULTS

Fifty-six (74%) patients survived 3 months to 12 years posttransplant. Cumulative 1- and 5-year patient survival data are 79% and 70%, respectively. However, with the introduction of prophylactic intravenous gancyclovir and the exclusion of hepatitis B virus (HBV) IgG core Ab-positive donors, the projected 5-year pediatric survival has been >80%. Early (<1 month) post-liver-transplant mortality was low, but included: primary malfunction (n = 1); inferior vena cava thrombosis (n = 1); bleeding esophageal ulcer (n = 1); and sepsis (n = 1). Late morbidity and mortality was mainly due to infections: de novo hepatitis B (5 patients, 2 deaths); Epstein-Barr virus (EBV)-related posttransplantation lymphoproliferative disease (12 patients, 7 deaths); and cytomegalovirus disease (10 patients, 5 deaths). Tuberculosis (TB) treatment in three patients was complicated by chronic rejection (n = 1) and TB drug-induced subfulminant liver failure (n = 1).

CONCLUSIONS

Despite limited resources, a successful pediatric program has been established with good patient and graft survival figures and excellent quality of life. Shortage of donors due to HBV and human immunodeficiency virus (HIV) leads to significant waiting list mortality and infrequent transplantation.

Liver transplantation for HBV and management of reinfection

Follicular non-Hodgkin's lymphoma (NHL) represents the most common indolent lymphoma with a median survival of 10 years. A new prognostic index (FLIPI) provides prognostic information at diagnosis and at relapse. Initial treatments combining monoclonal antibody therapy using rituximab with chemotherapy appear to increase the response rate and decrease the risk of relapse with little increase in toxicity. Promising phase III trial results demonstrating improvements in outcome using rituximab have recently been reported. A number of phase II trials have also demonstrated encouraging activity combining radiolabeled antibodies in sequence with chemotherapy. The role of high-dose therapy and autologous transplantation is becoming more defined, with improvements in progression-free survival observed in the upfront and relapsed setting. The application of allogeneic transplantation, once restricted to young otherwise healthy patients has shown encouraging activity in older, relapsed, and refractory patients using nonmyeloablative conditioning regimens. These new treatment options make the management of newly diagnosed patients both exciting and a challenge.

Intraoperative blood transfusion requirement is the main determinant of early surgical re-intervention after orthotopic liver transplantation

Liver transplantation is the treatment of choice in selected patients with end-stage liver disease. Postoperative complications often require surgical re-intervention. This study is a retrospective single-centre study to assess the incidence and type of surgical re-intervention during the in-hospital period after liver transplantation and to identify predictors of this re-intervention. From 1994 to 2002, 231 consecutive adult liver transplantations were performed. Re-intervention was classified as biliary, vascular, bleeding, septicaemia, re-transplantation or as miscellaneous. One hundred and thirty-nine surgical re-interventions were performed in 79 of 231 patients (34%). Septicaemia (44%) and bleeding (27%) were the most frequent indications for re-intervention, followed by biliary (10%) re-intervention. Vascular re-intervention, re-transplantation, and re-intervention for miscellaneous reasons, were performed in 7% each. Of all analysed variables (gender, age, diagnosis, acute liver failure, Child-Pugh classification, Karnofsky score, previous abdominal surgery, creatinine clearance, prothrombin time, anti-thrombin, platelet count, surgical technique, cold ischaemia time, warm ischaemia time, functional anhepatic time, anatomic anhepatic time, revascularisation time, year of transplantation, aprotinin administration, transfused platelet concentrate, and red blood cell transfusion requirements), only the number of transfused red blood cell concentrates (RBCs) was identified as a predictor of surgical re-intervention. Median RBC transfusion requirement during liver transplantation was 2.9 l (range 0-18.8 l) in the re-intervention group compared with 1.5 l (range 0-13.4 l) in the non-re-intervention group (P<0.001). This study revealed intraoperative blood loss as the main determinant of early surgical re-intervention after liver transplantation and emphasises the need for further attempts to control blood loss during liver transplantation.

Intraoperative blood transfusion requirement is the main determinant of early surgical re-intervention after orthotopic liver transplantation

Liver transplantation is the treatment of choice in selected patients with end-stage liver disease. Postoperative complications often require surgical re-intervention. This study is a retrospective single-centre study to assess the incidence and type of surgical re-intervention during the in-hospital period after liver transplantation and to identify predictors of this re-intervention. From 1994 to 2002, 231 consecutive adult liver transplantations were performed. Re-intervention was classified as biliary, vascular, bleeding, septicaemia, re-transplantation or as miscellaneous. One hundred and thirty-nine surgical re-interventions were performed in 79 of 231 patients (34%). Septicaemia (44%) and bleeding (27%) were the most frequent indications for re-intervention, followed by biliary (10%) re-intervention. Vascular re-intervention, re-transplantation, and re-intervention for miscellaneous reasons, were performed in 7% each. Of all analysed variables (gender, age, diagnosis, acute liver failure, Child-Pugh classification, Karnofsky score, previous abdominal surgery, creatinine clearance, prothrombin time, anti-thrombin, platelet count, surgical technique, cold ischaemia time, warm ischaemia time, functional anhepatic time, anatomic anhepatic time, revascularisation time, year of transplantation, aprotinin administration, transfused platelet concentrate, and red blood cell transfusion requirements), only the number of transfused red blood cell concentrates (RBCs) was identified as a predictor of surgical re-intervention. Median RBC transfusion requirement during liver transplantation was 2.9 l (range 0-18.8 l) in the re-intervention group compared with 1.5 l (range 0-13.4 l) in the non-re-intervention group (P<0.001). This study revealed intraoperative blood loss as the main determinant of early surgical re-intervention after liver transplantation and emphasises the need for further attempts to control blood loss during liver transplantation.

One-year protocol liver biopsy can stratify fibrosis progression in liver transplant recipients with recurrent hepatitis C infection

Determinants of progression to cirrhosis in hepatitis C virus (HCV) infection have been well described in the immunocompetent population but remain poorly defined in liver transplant (LT) recipients. This cohort study determines the factors contributing to the development of fibrosis and its rate of progression in the allograft. Predictive factors analyzed include: demographics, host and donor factors, surgery-related variables (cold and warm ischemia time), rejection episodes, cytomegalovirus infection (CMV), and immunosuppression. Over 12 years, 842 adult LTs were performed at our institution; 358 for the indication of HCV. A total of 264 patients underwent protocol liver biopsies at month 4 and yearly after LT. Using the modified Knodell system of Ishak for staging fibrosis, the median fibrosis progression rate was .8 units/year (P < .001). Rapid fibrosis progression (> .8 units/year) was best identified by liver histology performed at 1 year. Donor age > 55 years was associated with rapid fibrosis progression and development of cirrhosis (P < .001). In contrast, donor age < 35 years was associated with slower progression of fibrosis (P = .003). Risk factors for graft loss due to recurrent HCV included recipient age > 35 years (P = .01), donor age > 55 years (P = .005), and use of female donor allografts (P = .03). In conclusion, fibrosis progression in HCV-infected LT recipients occurs at a rate of .8 units/year. Increased donor age has a major impact on disease progression, graft failure, and patient survival. A liver biopsy performed at 1 year posttransplant can help identify those patients more likely to develop progressive disease and may allow better targeting of antiviral therapy.

Serum from patients with fulminant hepatic failure causes hepatocyte detachment and apoptosis by a beta(1)-integrin pathway

Hepatocyte transplantation is restricted by the impaired ability of hepatocytes to engraft and survive in the damaged liver. Understanding the mechanisms that control this process will permit the development of strategies to improve engraftment. We studied changes in liver matrix during acute injury and delineated the mechanisms that perturb the successful adhesion and engraftment of hepatocytes. Collagen IV expression was increased in sinusoidal endothelium and portal tracts of fulminant hepatic failure explants, whereas there were minimal changes in the expression of fibronectin, tenascin, and laminin. Using an in vitro model of cellular adhesion, hepatocytes were cultured on collagen-coated plates and exposed to serum from patients with liver injury to ascertain their subsequent adhesion and survival. There was a rapid, temporally progressive decrease in the adhesive properties of hepatocytes exposed to such serum that occurred within 4 hours of exposure. Loss of activity of the beta1-integrin receptor, which controls adhesion to collagen, was seen to precede this loss of adhesive ability. Addition of the beta1-integrin activating antibody (TS2/16) to cells cultured with liver injury serum significantly increased their adhesion to collagen, and prevented significant apoptosis. In conclusion, we have identified an important mechanism that underpins the failure of infused hepatocytes to engraft and survive in liver injury. Pretreating cells with an activating antibody can improve their engraftment and survival, indicating that serum from patients with liver injury exerts a defined nontoxic biological effect. This finding has important implications in the future of cellular transplantation for liver and other organ diseases.

Live donor liver transplantation without blood products: strategies developed for Jehovah's Witnesses offer broad application

OBJECTIVE

Developing strategies for transfusion-free live donor liver transplantation in Jehovah's Witness patients.

SUMMARY BACKGROUND DATA

Liver transplantation is the standard of care for patients with end-stage liver disease. A disproportionate increase in transplant candidates and an allocation policy restructuring, favoring patients with advanced disease, have led to longer waiting time and increased medical acuity for transplant recipients. Consequently, Jehovah's Witness patients, who refuse blood product transfusion, are usually excluded from liver transplantation. We combined blood augmentation and conservation practices with live donor liver transplantation (LDLT) to accomplish successful LDLT in Jehovah's Witness patients without blood products. Our algorithm provides broad possibilities for blood conservation for all surgical patients.

METHODS

From September 1998 until June 2001, 38 LDLTs were performed at Keck USC School of Medicine: 8 in Jehovah's Witness patients (transfusion-free group) and 30 in non-Jehovah's Witness patients (transfusion-eligible group). All transfusion-free patients underwent preoperative blood augmentation with erythropoietin, intraoperative cell salvage, and acute normovolemic hemodilution. These techniques were used in only 7%, 80%, and 10%, respectively, in transfusion-eligible patients. Perioperative clinical data and outcomes were retrospectively reviewed. Data from both groups were statistically analyzed.

RESULTS

Preoperative liver disease severity was similar in both groups; however, transfusion-free patients had significantly higher hematocrit levels following erythropoietin augmentation. Operative time, blood loss, and postoperative hematocrits were similar in both groups. No blood products were used in transfusion-free patients while 80% of transfusion-eligible patients received a median of 4.5+/- 3.5 units of packed red cell. ICU and total hospital stay were similar in both groups. The survival rate was 100% in transfusion-free patients and 90% in transfusion-eligible patients.

CONCLUSIONS

Timely LDLT can be done successfully without blood product transfusion in selected patients. Preoperative preparation, intraoperative cell salvage, and acute normovolemic hemodilution are essential. These techniques may be widely applied to all patients for several surgical procedures. Chronic blood product shortages, as well as the known and unknown risk of blood products, should serve as the driving force for development of transfusion-free technology.