Use of daclizumab as initial immunosuppression in liver transplant recipients with impaired renal function

Renal function after liver transplantation: Real-world experience with basiliximab induction and delayed reduced-dose tacrolimus

BACKGROUND

Routine use of delayed reduced-dose calcineurin-inhibitor treatment with induction immunosuppression in liver transplantation to minimize post-operative kidney injury is still scarce.

AIM

To evaluate real-world experience of basiliximab induction with delayed reduced-dose tacrolimus.

METHODS

In a retrospective cohort study, kidney function was evaluated pre- and postoperatively by measured glomerular filtration rate (mGFR). Adult patients undergoing liver transplantation between 2000 and 2017 were divided into a conventional treatment group (immediate-introduction of tacrolimus, target trough levels 10-15 ng/mL, and corticosteroids, n = 203) and a revised treatment group (basiliximab induction, reduced-dose tacrolimus, target through levels 5-8 ng/mL, delayed until day three, and mycophenolate mofetil 2000 mg/day, n = 343).

RESULTS

Mean mGFR was similar between groups at wait-listing (85.3 vs 84.1 ml/min/1.73m², p = 0.60), but higher in the revised treatment group at 3 (56.8 vs 63.4 ml/min/1.73m², p = 0.004) and 12 months post-transplant (60.9 vs 69.7 ml/min/1.73m², p<0.001); this difference remained after correcting for multiple confounders and was independent of pre-transplant mGFR. In the revised treatment group, biopsy proven acute rejection rate was lower (38% vs. 21%, p<0.001), and graft-survival better (p = 0.01).

CONCLUSION

Basiliximab induction with delayed reduced-dose tacrolimus is associated with less kidney injury when compared to standard-dose tacrolimus, without increased risk of rejection, graft loss or death.

Adverse Effects of Immunosuppression: Infections

Immunosuppressive therapies are currently indicated for a wide range of diseases. As new agents emerge and indications evolve the landscape grows increasingly complex. Therapies can target pathologic immune system over-activation in rheumatologic or autoimmune disease, or conditioning and graft versus host disease (GVHD) prophylactic regimens may eliminate or inhibit host immune function to improve graft survival and risk of complication in solid organ transplantation (SOT) or hematopoietic stem cell transplantation (HSCT). With immunosuppressive therapy, infections occur. Complex disease states, host factors, and concomitant therapies contribute to a "net state" of immunosuppression that must be considered and may confound perceived increased infection risks in patients receiving treatment.

Renal dysfunction in patients with cirrhosis: Where do we stand?

Patients with cirrhosis and renal failure are high-risk patients who can hardly be grouped to form precise instructions for diagnosis and treatment. When it comes to evaluate renal function in patients with cirrhosis, determination of acute kidney injury (AKI), chronic kidney disease (CKD) or AKI on CKD should be made. First it should be excluded the prerenal causes of AKI. All cirrhotic patients should undergo renal ultrasound for measurement of renal resistive index in every stage of liver dysfunction and urine microscopy for differentiation of all causes of AKI. If there is history of dehydration on the ground of normal renal ultrasound and urine microscopy the diuretics should be withdrawn and plasma volume expansion should be tried with albumin. If the patient does not respond, the correct diagnosis is HRS. In case there is recent use of nephrotoxic agents or contrast media and examination shows shock, granular cast in urinary sediment and proteinuria above 0.5 g daily, acute tubular necrosis is the prominent diagnosis. Renal biopsy should be performed when glomerular filtration rate is between 30-60 mL/min and there are signs of parenchymal renal disease. The acute renal function is preferable to be assessed with modified AKIN. Patients with AKIN stage 1 and serum creatinine ≥ 1.5 mg/dL should be at close surveillance. Management options include hemodynamic monitoring and management of fluid balance and infections, potentially driving to HRS. Terlipressin is the treatment of choice in case of established HRS, administered until there are signs of improvement, but not more than two weeks. Midodrine is the alternative for therapy continuation or when terlipressin is unavailable. Norepinephrine has shown similar effect with terlipressin in patients being in Intensive Care Unit, but with much lower cost than that of terlipressin. If the patient meets the requirements for transplantation, dialysis and transjugular intrahepatic portosystemic shunt are the bridging therapies to keep the transplant candidate in the best clinical status. The present review clarifies the latest therapeutic modalities and the proposed recommendations and algorithms in order to be applied in clinical practice.

A randomized controlled trial of daclizumab versus anti-thymocyte globulin induction for heart transplantation

Background

The purpose of this study was to test the efficacy and safety of daclizumab (DZM) versus anti-thymocyte globulin (ATG) as a component of induction therapy in heart transplant recipients.

Methods

Thirty heart transplant patients were randomized to receive either ATG or DZM during induction therapy. Patients in the DZM group received an initial dose of 2 mg/kg intravenous (IV) at the time of transplant and 1 mg/kg IV on postoperative day 4.

Discussion

Recipient, donor, and intraoperative variables did not differ significantly between groups. The cost of induction therapy, total drug cost, and hospital ward costs were significantly less for the DZM group. Average absolute lymphocyte and platelet counts were significantly higher in the DZM group. There were no significant differences in the incidence of rejection, infection, malignancy, or steroid-induced diabetes. One year survival was excellent in both groups (87%, P = 0.1). Daclizumab is a safe component of induction therapy in heart transplantation.

Induction immunosuppression in liver transplantation: a review

Antibody therapy for induction is seldom used in liver transplantation in the United States, but continues to be used in approximately 10% of patients. The most commonly used antibody at the current time is basiliximab (Simulect, Novartis) and is used in adults with renal dysfunction at the time of liver transplantation with the intention of delaying introduction of calcineurin-inhibitors. In children, the same antibody is commonly used in order to reduce rates of acute rejection. Most patients, adult and pediatric, are treated with initially higher levels of tacrolimus rather than antibody induction.

Current concepts in pediatric liver transplantation

Liver transplantation is the definitive treatment for end-stage liver disease in both children and adults. Advances over the last 2 decades have resulted in excellent patient and graft survival rates in what were previously cases of fatal disorders. These developments have been due to innovations in surgical technique, increased surgical experience, refinements in immunosuppressive regimens, quality improvements in intraoperative anesthetic management, better understanding of the pathophysiology of the liver diseases, and better preoperative and postoperative care. Remarkably, the use of split-liver and living-related liver transplantation surgical techniques has helped mitigate the well-recognized national organ shortage. This review will discuss the major aspects of pediatric liver transplantation as it pertains to indication for transplantation, recipient selection and listing for orthotopic liver transplantation, pre-orthotopic liver transplantation care of children, optimal timing of orthotopic liver transplantation, surgical technical considerations, postoperative care and complications, and patient and graft survival outcomes.

Pediatric liver transplantation for inherited metabolic liver disease: a single-center experience

OBJECTIVE

We performed single-center outcome comparison of pediatric recipients who underwent liver transplantation for either genetic or metabolic disease including the clinical impact of using heterozygote parents as living donors.

MATERIALS AND METHODS

Pediatric liver transplant recipients from September 2007 to December 2010 were included. Patients were separated into 2 categories by etiology of liver disease: (1) genetic or metabolic liver disease (G/M) and (2) nongenetic or metabolic liver disease (non-G/M), which included all other remaining etiologies combined. Patient demographics, recipient and donor characteristics, graft type, operative data, recipient complications, allograft and patient survival were analyzed.

RESULTS

Forty liver transplants were performed on 40 patients; 18 were transplanted for G/M; mean waiting time was 101 days for G/M group and 57 days for non-G/M group; 9 patients were listed as status 1, 5 were granted PELD/MELD exceptions; the overall mean PELD/MELD score was 21. Four G/M patients had hepatocellular carcinoma in the explant without microvascular invasion. Overall complications requiring either surgery or interventional radiology occurred in 14 patients-G/M (n = 5); CMV viremia was seen in 11 patients (G/M, n = 1); detectable EBV DNA was detectable in 8 patients (G/M, n = 4), acute cellular rejection was seen in 10 (G/M, n = 5), postransplant lymphoproliferative disease occurred in 2 G/M patients; and 1 G/M patient showed significantly improved posttransplant neurologic motor function. Children with G/M who received a living donor liver transplant from heterozygote parents did well without any signs of expressing underlying metabolic disease. Posttransplant graft and patient overall survival at 12 months for G/M and non-G/M was 100%, and at 36 months, 83% and 100%, respectively.

CONCLUSION

The majority of children transplanted for either genetic or metabolic disease were status 1 or awarded UNOS exception points. Cadaveric split livers and live donors including obligate heterozygotes resulted in excellent allograft and patient survival outcomes. In metabolic and genetic liver diseases, close follow-up and timely transplantation can preclude malignant spread and prevent disease progression and consequences, as well as reverse neurologic sequelae.

Basiliximab induction and delayed calcineurin inhibitor initiation in liver transplant recipients with renal insufficiency

BACKGROUND

Renal insufficiency (RI) is common after liver transplantation (LT) and may worsen due to calcineurin inhibitor (CNI) use. We compared LT outcomes using basiliximab induction and delayed CNI initiation to controls with a standard CNI regimen in patients with peri-LT RI.

METHODS

All adults transplanted January 2004 to December 2007 with peri-LT RI (hemodialysis or creatinine ≥1.5 within 1 week of LT) were included in a retrospective nonrandomized cohort. Outcomes including 30-day and 1-year patient and graft survival and renal function were compared between basiliximab and control groups.

RESULTS

Two hundred twenty-nine patients (102 basiliximab, 127 controls) were analyzed, mean age 54 years, 72% men, 54% with hepatitis C virus. Mean model for end-stage liver disease (28.2 vs. 20.0; P<0.001) and creatinine (1.9 vs. 1.6; P=0.001) were higher and more patients were on hemodialysis at LT (29% vs. 6%; P<0.001) in the basiliximab group. 30-day patient (99% vs. 97%; P=0.26) and graft survival (98% vs. 95%; P=0.17), 1-year patient (87% vs. 87%; P=0.89) and graft survival (86% vs. 82%; P=0.37), mean creatinine at 1-year (1.5 vs. 1.5 mg/dL; P=0.82), and treated acute rejection (6% vs. 6%; P=0.90) were similar between basiliximab and control groups, respectively. In multivariable logistic regression, basiliximab was not significantly associated with 30-day (odds ratio, 0.10; P=0.11) or 1-year (odds ratio, 0.97; P=0.94) survival, controlling for age, previous LT, model for end-stage liver disease, and hepatitis C virus.

CONCLUSIONS

Basiliximab induction resulted in 30-day and 1-year patient, graft and renal outcomes comparable with a control group receiving standard CNI-based immunosuppression. Antibody induction with delayed CNI should be further studied prospectively.

Evolving concepts in the selection of immunosuppression regimen for liver transplant recipients

The introduction of calcineurin inhibitor (CNI) based immunosuppression has revolutionized the field of liver transplantation by dramatically reducing the incidence of acute cellular rejection and prolonging patient and allograft survival. However, the introduction of CNIs has also come at the price of increased patient morbidity, particularly with regard to the well-known nephrotoxic effects of the medications. In an effort to minimize the adverse effects, immunosuppression regimen have evolved to include the use of various induction agents and purine synthesis inhibitors to limit the dose of CNI necessary to achieve low acute cellular rejection rates. Careful assessments of risks and benefits are needed as these newer agents have their own side effect profiles. In addition, the impact of newer immunosuppression regimen on hepatitis C (HCV) recurrence has not been completely elucidated. This review will provide an overview of the most common immunosuppression regimen used in liver transplantation and discuss their impact on acute cellular rejection, patient and allograft survival, and HCV recurrence.

Daclizumab induction therapy in liver transplant recipients with renal insufficiency

BACKGROUND

The role of interleukin 2 (IL-2) receptor antibodies to avoid the nephrotoxic effects of calcineurin inhibitors in the early post-liver transplant (LT) period is not well defined.

AIM

To examine the use of daclizumab induction in LT recipients with renal insufficiency.

METHODS

Between 2002 and 2005, 62 patients (median pre-LT creatinine 2.4 mg/dL, IQR 1.9-3.7) received daclizumab induction with tacrolimus being administered when serum creatinine was <2.0 mg/dL. A concurrent comparison group (n = 221, 2002-2005) received tacrolimus-based immunosuppression without daclizumab (median pre-LT creatinine 1.1 mg/dL, IQR 0.9-1.4). A second historical comparison group (n = 103, 1995-2005) not receiving daclizumab was matched to the daclizumab patients by pre-LT serum creatinine (2.2 mg/dL, IQR 1.8-3.1). All patients received mycophenolate mofetil and steroids.

RESULTS

Serum creatinine improved in the daclizumab group (-1.0 mg/dL, IQR -2.2 to -0.4) and worsened in the concurrent comparison group (+0.2 mg/dL, IQR 0-0.5) from pre-LT to 4 months. However, there was no difference when daclizumab group was compared with the historical comparison group matched on pre-LT creatinine (median change: -0.8 mg/dL vs. -0.7 mg/dL). Daclizumab induction was not associated with improvement in renal function at 4 months (P = 0.34) after adjusting for pre-LT creatinine, age, gender, hepatitis C status and simultaneous liver kidney transplantation.

CONCLUSION

The incremental benefit offered by induction therapy with IL-2 receptor antibodies to preserve renal function is questionable.

Two doses of humanized anti-CD25 antibody in renal transplantation: a preliminary comparative study

HuCD25mAb is a humanized anti-CD25 antibody which has the same amino acid sequence as daclizumab (Zenapax, Roche). HuCD25mAb is expressed in Chinese hamster ovary (CHO) cells while daclizumab is expressed in the NSO myeloma cell line. A comparative study was performed to evaluate the pharmacokinetics and pharmacodynamics between huCD25mAb and daclizumab in a two-dose regimen incorporating triple immunosuppressant treatment regimens (MMF, CsA and steroids). Fifteen patients were enrolled and randomized to receive intravenous infusion of either huCD25mAb (n = 10) or daclizumab (n = 5) at a dosage of 1 mg.kg(-1) on operation day 0 and post-operation day 14. Serum concentrations of huCD25mAb and daclizumab were measured by a validated competitive ELISA. Subgroups of CD3(+), CD25(+), CD4(+) and CD8(+) lymphocytes were monitored periodically by flow cytometry. The concentration-time curves of huCD25mAb and daclizumab were found to fit well to a one-compartment model. A significant decline of proportion (%) of CD3-CD25(+) and CD3(+)CD25(+) lymphocytes was observed 30 min after first infusion on day 0 (3.40 +/- 1.83 to 0.03 +/- 0.07, 3.35 +/- 2.02 to 0.37 +/- 0.49), and these levels remained low for at least 70 days (0.03 +/- 0.05, 0.31 +/- 0.47). All pharmacokinetic parameters of huCD25mAb seemed similar to those of daclizumab. The two-dose huCD25mAb regimen was as effective as daclizumab in rapidly achieving high therapeutic concentration in the treated patients, and a significant decrease of CD3(-)CD25(+) and CD3(+)CD25(+) lymphocytes was demonstrated. This suggests that two-dose regimen is feasible in maintaining host immunosuppression and may provide an effective and economical strategy for reducing incidence of acute graft rejection.

Immunosuppression with low-dose daclizumab in liver transplant recipients with impaired kidney function: a single-center experience

BACKGROUND

Nephrotoxicity of calcineurin inhibitors (CNI) may exert detrimental effects, particularly in orthotopic liver transplantation (OLT) patients with impaired kidney function. Immunosuppression with daclizumab permits delayed introduction of CNI, and may be preferred for patients with kidney dysfunction. This retrospective analysis of our experience using daclizumab was performed among patients who underwent transplantation with impaired kidney function.

METHODS

We analyzed 168 patients. A serum creatinine (Cr) level >1.5 mg/dL was the indication for a protocol with low-dose daclizumab (50 mg intravenous [IV], day 0 and day 4), mycophenolate mofetil (MMF; 500 mg twice daily IV/orally), and tapering doses of prednisolone from day 0 after OLT. CNI were introduced at day 4-15 after OLT. Patients with a Cr level <1.5 mg/dL received immunosuppression with CNI+MMF+steroids or CNI+steroids.

RESULTS

Fourteen patients fulfilled the criterion for daclizumab immunosupression. Their Cr and creatinine clearance (CrCl) values at OLT were 2.85 +/- 1.22 mg/dL and 19 +/- 11 mL/min, respectively. In the remaining 154 patients, Cr and CrCl results were 0.88 +/- 0.3 mg/dL and 107 +/- 82 mL/min, respectively. At discharge, the daclizumab group showed Cr and CrCl estimates of 0.97 +/- 0.45 mg/dL and 86 +/- 34 mL/min (P < .0001 for both, when compared with prior to OLT). Both Cr and CrCl levels at discharge were not different from those values of patients who underwent transplantation with normal kidney function. The incidence of acuterejection was 14% in the daclizumab group and 18% in the other recipients (P = not significant [NS]).

CONCLUSIONS

Immunosuppression with low-dose daclizumab and delayed introduction of CNI was safe and did not increase the risk of an acute rejection episode, thus offerring an excellent therapeutic option for patients who undergo transplantation with impaired kidney function.

A prospective randomized open study in liver transplant recipients: daclizumab, mycophenolate mofetil, and tacrolimus versus tacrolimus and steroids

This open-label, randomized study compared the efficacy of a regimen of corticosteroids and tacrolimus (standard therapy group, n = 79) with a regimen of daclizumab induction therapy in combination with mycophenolate mofetil and tacrolimus (modified therapy group, n = 78) in primary liver transplant recipients. The primary endpoint was biopsy-proven acute rejection (BPAR) at 24 weeks. Secondary endpoints included time to rejection and patient and graft survival. The incidence of BPAR was significantly reduced in the modified therapy group compared to the standard therapy group (11.5% versus 26.6%, respectively, P = 0.017). The time to rejection was significantly shorter in the standard therapy group compared with the modified therapy group (P = 0.044). There was no significant difference between groups in patient or graft survival. Hepatitis C virus-positive patients exhibited no differences from hepatitis C virus-negative patients with respect to the incidence of BPAR. A steroid-sparing regimen of daclizumab, mycophenolate mofetil, and tacrolimus was effective and well tolerated in the prevention of BPAR in adult liver transplant recipients in comparison with a standard regimen of tacrolimus and steroids.

A comprehensive review of immunosuppression used for liver transplantation

Since liver transplantation was approved for the treatment of end stage liver disease, calcineurin inhibitors (CNI's) have played a critical role in the preservation of allograft function. Unfortunately, these medications cause a variety of Side effects such as diabetes, hypertension and nephrotoxicity which in turn result in significant morbidity and reduced quality of life. A variety of newer immunosuppressants have been evaluated over the last decade in an attempt to either substitute for CNI's or use with reduced dose CNI's while still preserving allograft function However, current data does not recommend complete cessation of CNI's due to unacceptably high rates of allograft rejection. As these medications have their own unique adverse effects, a careful assessment on their risks and benefits is essential, particularly when additive or synergistic effects with CNI's may occur. Furthermore, the impact of these newer medications on the risk of hepatitis C recurrence and progression remains to be elucidated. Controlled trials are urgently required to assist transplant physicians with choosing the optimum immunosuppressive regimen for their patients. This review will discuss commonly used immunosuppressants prescribed in liver transplantation, emerging therapties and where appropriate, the impact of these medications on the recurrence of hepatitis C after liver transplantation.

Daclizumab treatment for multiple sclerosis

Multiple sclerosis is a chronic inflammatory and demyelinating disease of the central nervous system and the leading cause of neurologic disability in young adults. Established therapies, such as interferon and glatiramer, have only partial effects, and they offer limited or no effect on the progression of multiple sclerosis. The etiology of multiple sclerosis is unclear; however, the disease is presumed to be a T-cell-mediated autoimmune disease influenced by genetic and environmental factors. Therefore, targeting of lymphocytes may be a promising means of therapy for multiple sclerosis. Daclizumab is a humanized monoclonal antibody approved for use in preventing renal allograft rejection. The agent is under investigation in phase II trials for the treatment of multiple sclerosis and has demonstrated positive clinical outcomes, including decreased relapse rates. Adverse events included urinary tract infections, respiratory tract infections, paresthesias, mild leukopenia, transient elevations in liver enzyme and bilirubin levels, rash, postinfusion reactions (fever), lymphadenopathy, transient thrombocytopenia, and nausea. Daclizumab may be an alternative or add-on therapy when conventional immunomodulators fail or when existing approved therapies cannot be used. Besides ongoing phase II trials, additional phase II or III trials are required to determine the extended benefits of the agent, as well as clinical outcomes.

Preserving renal function in liver transplant recipients with rabbit anti-thymocyte globulin and delayed initiation of calcineurin inhibitors

Early renal dysfunction following liver transplantation is associated with increased morbidity and mortality. To evaluate the impact of delayed initiation of calcineurin inhibitor on renal function, we conducted a retrospective study comparing 118 liver transplant recipients who received rabbit anti-thymocyte globulin and delayed initiation of calcineurin inhibitor with 80 liver transplant recipients who received no antibody and early initiation of calcineurin inhibitor (control group). All patients received mycophenolate mofetil and steroids. Delayed calcineurin inhibitor initiation with anti-thymocyte globulin was associated with significant improvement in renal function throughout the first year post-transplant. At 12 months post-transplant, patients treated with this regimen experienced lower serum creatinine (1.4 +/- 0.5 versus 1.7 +/- 0.5 mg/dL, P < 0.001), a higher estimated glomerular filtration rate (57.4 +/- 20.5 versus 43.7 +/- 14.4 mL/min/1.73 m(2), P < 0.001), and less dependence on dialysis (0.8% versus 13%, P < 0.001) in comparison with no antibody and early calcineurin inhibitor initiation. Patient survival and graft survival were similar between groups; however, there was a trend of a lower incidence of early biopsy-proven acute rejection with anti-thymocyte globulin. Overall infection and cytomegalovirus infection were significantly lower in anti-thymocyte globulin-treated patients, and there was no increased incidence of hepatitis C recurrence in comparison with controls. In conclusion, delayed initiation of calcineurin inhibitor with anti-thymocyte globulin in liver transplant recipients is safe and is associated with improvements in renal function and a lower incidence of early acute rejection in comparison with no antibody and early initiation of calcineurin inhibitor.

Corticosteroid-free immunosuppression with daclizumab in HCV(+) liver transplant recipients: 1-year interim results of the HCV-3 study

This work is a 1-yr interim analysis of a prospective, randomized, multicenter trial evaluating the effect of corticosteroid-free immunosuppression on hepatitis C virus-positive (HCV(+)) liver transplant recipients following liver transplantation (LT). Patients received tacrolimus and corticosteroids (Arm 1; n = 80); tacrolimus, corticosteroids, and mycophenolate mofetil (MMF) (Arm 2; n = 79); or daclizumab induction, tacrolimus, and MMF (Arm 3; n = 153). At 1 yr, 64.1%, 63.4%, and 69.4% of patients achieved the composite primary endpoint of freedom from rejection, freedom from HCV recurrence, and freedom from treatment failure, respectively. Excellent patient and graft survival did not differ significantly among treatment arms. Freedom from HCV recurrence at 1 yr was 61.8 +/- 6.2%, 60.1 +/- 6.1%, and 67.0 +/- 4.3% in Arms 1, 2, and 3, respectively (P = not significant). Freedom from rejection was significantly higher in Arm 3 compared to Arm 1 (93.0 +/- 2.2% vs. 81.9 +/- 4.4%; P = 0.011). Multivariate analysis identified acute rejection (hazard ratio = 2.692; P = 0.001) and donor age (hazard ratio = 1.015; P = 0.001) as significant risk factors for HCV recurrence. HCV recurrence was not influenced by recipient demographics, HCV genotype, or immunosuppression. In conclusion, these results suggest that a corticosteroid-free regimen of tacrolimus and MMF following daclizumab induction is safe and effective in HCV(+) liver transplant recipients.

Evaluation of renal function in transplantation

Kidney dysfunction causes a myriad of adverse influences on posttransplant outcomes necessitating accurate assessment of kidney function for patient management. This evaluation assists in guiding treatment decisions, with the ultimate aim of allaying renal function decline. In clinical practice, renal function is typically estimated from serum creatinine levels, creatinine-based estimation equations or creatinine clearance; however, each of these methods has demonstrated limitations when used in the kidney transplant setting. Equally important is the emerging recognition of the incidence and impact of kidney dysfunction in recipients of nonrenal solid organ transplantation. The performance of commonly used estimation equations and methods for measuring kidney function in renal and liver transplant patients are overviewed here along with their potential roles in clinical transplantation.

Avoiding calcineurin inhibitors in the early post-operative course in high-risk liver transplant recipients: The role of extracorporeal photopheresis

The aim of this work is to report on the results of a single-center, prospective study on the feasibility of calcineurin-inhibitor (CNI)-staggered immunosuppression by use of extracorporeal photopheresis (ECP) in liver transplant (LT) recipients at risk of renal and neurological complications. Patients were matched on a 1:1 basis with historical controls on standard CNI immunosuppression. ECP patients were treated with ECP plus antimetabolites and/or steroids, while CNIs were withheld until clinically indicated. Thirty-six patients were evaluated: 18 ECP patients and 18 controls. ECP was tolerated in 100% of cases. CNI were introduced at a median of 8 days (4-55) in 17 ECP patients, while one patient was on a fully CNI-sparing regimen 22 months after LT. Acute rejection occurred in 27.7% patients in ECP (5/18) versus 16.7% in controls (3/18) (P = ns) with a shorter time to rejection in ECP (36 +/- 31.3 days vs. 83.6 +/- 65.6 days; P = ns). All rejection episodes were amenable to medical treatment. Neurological and renal complications occurred in 22.2% (4/18) of patients in either group, but led to in-hospital mortality in 3 patients among controls versus 1 in ECP (P = ns). One-, 6-, and 12-month survival rates were 94.4, 88.1, and 88.1% in ECP versus 94.4, 77.7, and 72.2% among controls (P < 0.0001). ECP seems to allow for management of high-risk LT recipients in the early post-transplant course and reduction of CNI-related mortality. Continued data validation is favored to assess the impact of ECP on long-term graft and patient survival.

Replacement of calcineurin inhibitors with daclizumab in patients with transplantation-associated microangiopathy or renal insufficiency associated with graft-versus-host disease

Transplantation-associated microangiopathy (TAM) or renal insufficiency (RI) after allogeneic hematopoietic stem cell transplantation is associated with a high mortality. As calcineurin inhibitors (CI) may contribute to TAM or RI, we evaluated the efficacy of replacing CI by daclizumab in patients with graft-versus-host disease (GVHD). Thirteen patients with GVHD-associated TAM and five patients with RI were treated with daclizumab 1 mg/kg intravenous (i.v.)/week, discontinuation of the CI and continuation of the remaining GVHD treatment. All patients had acute GVHD (steroid-sensitive (n=4), steroid-refractory (n=10)) or chronic GVHD (n=4) and were treated with CI before the start of daclizumab. Nine of 13 patients with TAM treated with daclizumab and discontinuation of CI achieved complete remission of TAM, two had stable disease, and one patient did not respond. Patients receiving daclizumab for RI without TAM showed stabilization (2/5) or improvement (3/5) of renal function. Four of 14 patients with acute GVHD achieved CR, two partial remission, eight patients did not respond and 11/14 died at a median of 39 days after start of the daclizumab. Our data demonstrate that replacement of CI by daclizumab can improve TAM and RI. However, mortality remains high in patients with acute GVHD.

A novel three-dose regimen of daclizumab in liver transplant recipients with hepatitis C: a pharmacokinetic and pharmacodynamic study

This study evaluated the pharmacokinetics and pharmacodynamics of a novel 3-dose regimen of daclizumab in de novo hepatitis C liver transplant recipients. In 30 of 156 recipients receiving daclizumab, mycophenolate mofetil, tacrolimus, and no steroids (Arm 3 of Hep C 3 Liver Study), daclizumab (2, 2, and 1 mg/kg, respectively) was given on days 1, 3, and 8 posttransplant, respectively, with trough, peak (C(max)), and CD25 saturation (CD(sat)) measured sequentially. Mean daclizumab C(max) was 50.3 microg/mL on day 1, and mean trough levels were 21.8, 25.7, and 9.9 microg/mL on days 3, 8, and 30, respectively. A significant decline in CD(sat) (mean, 15.7% to 4.7%) was observed on day 1 and was sustained throughout the study (2.8% on day 30). Daclizumab concentration > or = 5 microg/mL was the level where most of the effect on CD(sat) was noticed. Elevated baseline CD(sat) was observed in African Americans, patients weighing < or = 75 kg, and patients <60 years of age. After 365 days, 2 patients had experienced 3 rejections, 10 patients had recurrent hepatitis C, 4 patients died, and 2 grafts were lost. In conclusion, this novel 3-dose regimen is effective in rapidly achieving high therapeutic concentration of daclizumab and a significant decline in CD(sat) lasting over 30 days.

Initial immunosuppression in liver transplant recipients with impaired renal function

Acute renal failure (ARF) after liver transplantation is a factor of poor prognosis associated with a high mortality. Selection of the donor, recipient, and intraoperative and postoperative treatment has crucial importance in the management of these critical patients. Thus, optimization of the use of calcineurin inhibitors (CNI), the main nephrotoxic substances in the immediate postoperative period, may decrease ARF incidence, allowing for early recovery of renal function in this period. Most protocols are based on the reduction or late introduction of CNI, based on the use of mycophenolate mofetil (MMF) with/without antiCD25 (basilximab/daclizumab). Recently, thymoglobulin (ATG) is also being tested to further delay the use of the CNI. A 20%-30% acute rejection incidence with the usual protocols allows recovery of renal function in more than 80% of patients without increasing the incidence of infections or adverse effects. However, it is still unknown whether there is a long-term negative effect of chimeric-humanized monoclonal antibodies and MMF combination on reinfection with hepatitis C virus in transplant recipients.

Immunosuppressive agents in solid organ transplantation: Mechanisms of action and therapeutic efficacy

Effective immunosuppression is an essential pre-requisite for successful organ transplantation and improvements in outcome after transplantation have to a large extent been dependent on developments in immunosuppressive therapy. Here we provide an overview of the different immunosuppressive agents currently used in solid organ transplantation. A historical perspective on the development of immunosuppression for organ transplantation is followed by a review of the individual agents, with a focus on their mechanism of action and efficacy. Steroids, anti-proliferative agents (azathioprine and mycophenolate), calcineurin inhibitors (cyclosporine and tacrolimus) and TOR inhibitors (sirolimus and everolimus) are discussed along with both polyclonal and monoclonal antibody preparations. Many of the key clinical trials that underpin current clinical usage of these agents are described and side-effects of the different agents are highlighted. Finally, a number of newer agents still in various stages of clinical development are briefly considered.

Evaluation of renal function in liver transplant recipients receiving daclizumab (Zenapax), mycophenolate mofetil, and a delayed, low-dose tacrolimus regimen vs. a standard-dose tacrolimus and mycophenolate mofetil regimen: a multicenter randomized clinical trial

Posttransplant chronic renal failure, secondary to calcineurin inhibitor agents, is emerging as a major problem in liver transplantation. We report a randomized clinical trial comparing daclizumab, delayed low-dose tacrolimus (target trough level 4-8 ng/mL, starting day 4-6), Investigational Arm (n = 72), to standard tacrolimus induction/maintenance dosing, Standard Arm (n = 76), with mycophenolate mofetil and tapering corticosteroids in both study arms. The end-points were renal function indicated by the Modification of Diet in Renal Disease (MDRD). There was no significant difference in patient survival (86.6% Investigational Arm vs. 92.9% Standard Arm; P = 0.21) or acute rejection (23.2% vs. 27.7%, respectively; P = 0.68). Statistically significant differences in median glomerular filtration rate (GFR) were found in favor of the Investigational Arm. With the CG equation, the GFR at the end of the first week was 110.7 vs. 89.6 mL/min (P = 0.019) without significant differences thereafter. With the MDRD, statistically significant differences extended to the first posttransplant month (86.8 vs. 70.1 mL/min/1.73 m(2); P < 0.001) with and was seen at month 6 (75.4 vs. 69.5 mL/min/1.73 m(2); P = 0.038). In conclusion, delayed low-dose tacrolimus, in combination with daclizumab and mycophenolate mofetil, preserves early renal function post-liver transplantation without the cost of increased acute rejection.

The impact of thymoglobulin on renal function and calcineurin inhibitor initiation in recipients of orthotopic liver transplant: a retrospective analysis of 298 consecutive patients

BACKGROUND

Renal dysfunction remains the Achilles' heel of calcineurin inhibitor (CI)use. The purpose of this study was to assess our institutional, renal-sparing strategy using thymoglobulin (TMG) in recipients of orthotopic liver transplants.

METHODS

We performed a retrospective analysis of data from 298 adult recipients who were transplanted between 1991 and 2002. The patients were divided into two groups: those induced with TMG (group 1) and those that were not treated with this agent (group 2). A subgroup analysis was performed of patients with baseline serum creatinine values above 1.5 mg/dL (group 1A received TMG; group 2A did not). All patients received tacrolimus or cyclosporine (CyA) maintenance immunosuppression.

RESULTS

Indications and demographics were similar between the two groups. Although there was no difference in patient and graft survivals, there was a statistically significant benefit in the rejection-free graft survival at 1 year for group 1 (51% vs 39%; P =.02). Furthermore, serum creatinine at 6 months was lower for group 1, despite a similar baseline creatinine. Subgroup analysis for patients with baseline abnormal serum creatinines showed that group 1A displayed an improved rejection-free graft survival at 1 month but not at 1 year.

CONCLUSIONS

Thymoglobulin induction therapy may allow a delay in the initiation of CI therapy without compromising patient and graft survival, while preventing early rejection, even among patients with baseline renal dysfunction.

Immunosuppression in liver transplantation: beyond calcineurin inhibitors

Although calcineurin inhibitors (CNIs) remain the mainstay of immunosuppression in liver transplantation (LTX), their long-term toxicity significantly contributes to morbidity and mortality. The elucidation of mechanisms of alloimmunity and leukocyte migration have provided novel targets for immunosuppression development. The toxicities of these agents differ from that of the CNI and act additively or synergistically. CNI avoidance protocols in LTX have not been achieved routinely; however, pilot trials have begun to delineate the limitations and promises of such approaches. CNI-sparing protocols appear to be much more promising in balancing the early need for minimizing rejection while tapering doses and minimizing long-term toxicity.

Two-dose Daclizumab Induction Therapy in 209 Liver Transplants: A Single-Center Analysis

BACKGROUND

Patient and graft survival after liver transplantation are adversely affected by early posttransplant renal dysfunction. Therefore, our immunosuppressive strategies should be as "renal sparing" as possible. This is the largest published series to date using daclizumab induction therapy in a renal-sparing regimen.

METHODS

This is a retrospective, nonrandomized study comparing 209 adult liver transplants with daclizumab induction to 115 transplants with no induction.

RESULTS

Patient and graft survival were similar, despite higher pretransplant acuity of illness and older age in the induction group. Acute rejection within the first 6 months occurred less commonly in the induction group (25.4% vs. 39.1%, P=0.01), despite significantly delayed initiation and lower doses of a calcineurin inhibitor. Mycophenolate mofetil was used more commonly in induction patients, but the efficacy of daclizumab in preventing rejection was independent of this. Patients with a pretransplant creatinine concentration 1.5 mg/dL or less had less rejection if they received induction. Renal function worsened in noninduction patients but showed sustained improvement throughout follow-up in induction patients with a pretransplant creatinine concentration greater than 1.5 mg/dL. Induction therapy provided better rejection prophylaxis among those requiring temporary calcineurin inhibitor cessation because of renal dysfunction. The incidences of histologic hepatitis C recurrence and cytomegalovirus infection were similar in each group.

CONCLUSIONS

Liver recipients with and without pretransplant renal dysfunction have less acute rejection with daclizumab induction therapy. This is not associated with an increased risk of over-immunosuppression. Sustained renal improvement in recipients with pretransplant renal dysfunction is possible with daclizumab induction.

Evolution of immunosuppression in liver transplantation: contribution of cyclosporine

Liver transplantation has become the standard therapy for patients with end-stage liver disease or acute liver failure, with excellent outcomes in terms of quality of life and length of survival. The use of immunosuppressive agents, without any doubt, has played a crucial role in the establishment of this technique and improved short- and long-term survival rates. Eventually, mortality from acute or chronic rejection may be entirely eliminated. Minimizing the adverse effects of immunosuppressive agents is essential to improve long-term survival and quality of life. In this chapter, we review the history of immunosuppressive agents for liver transplantation with consideration of the pre- and the postcyclosporine eras. We also review the development and contributions of cyclosporine, the excellent outcomes from C2 monitoring, comparisons between the cyclosporine microemulsion and the oil-based formula, as well as between cyclosporine microemulsion versus tacrolimus. In addition, details are provided on the newer immunosuppressive agents: mycophenolate mofetil, sirolimus, and the IL-2 receptor antagonists, as well as agents in development: CAMPATH 1-H, thymoglobulin, everolimus, FT720, and FK778.

Estimation of glomerular filtration rates before and after orthotopic liver transplantation: evaluation of current equations

The ability to estimate rather than measure the glomerular filtration rate (GFR) in patients before and after liver transplantation would be helpful in estimating risk, dosing drugs, and assessing long-term toxicity of calcineurin inhibitors. Currently available equations for estimating the GFR have not been validated in either the pre- or post-liver transplant population. We have evaluated the performance of currently used formulas for the estimation of the GFR in this setting. Data were collected prospectively on patients who underwent liver transplantation between 1984 and 2001. GFR per 1.73 m2 was measured by I125 iothalamate in patients at the pretransplant evaluation and at 3 months, 1 year, and yearly posttransplant thereafter. GFR estimated by the Cockcroft-Gault equation, the Nankivell equation, and the equations from the Modification of Diet in Renal Disease (MDRD) Study (6, 5, and 4 variables) was compared with the measured GFR. Pretransplant GFR was available in 1,447 patients. The mean GFR was 90.7 +/- 40.5 mL/min. Values for r and r2 were highest for the MDRD Study 6-variable equation (0.70 and 0.49, respectively). Only 66% of estimates were within 30% of the measured GFR. At 3 months, 1 year, and 5 years posttransplant, the mean GFR was 59.5 +/- 27.1 mL/min, 62.7 +/- 27.8 mL/min, and 55.3 +/- 26.1 mL/min, respectively. Values for r and r(2) for the MDRD Study 6-variable equations at 1 and 5 years posttransplant were 0.74 (0.55) and 0.76 (0.58), respectively. At these time points, however, only 67% and 64% of the estimated GFR were within 30% of the measured GFR. MDRD Study equations had greater precision than other equations, but the precision was lower than reported for MDRD estimation of GFR in other populations. Better methods for estimating the GFR are required for evaluation of renal function before and after liver transplantation.

IL-2 receptor blockers in liver transplantation: initial experience with daclizumab in Chile

Monoclonal antibodies against the interleukin 2 receptor have been developed in an effort to decrease rejection rates and spare calcineurin inhibitors when renal dysfunction occurs after transplant. While success has been reported in kidney transplantation, its effectiveness in liver transplantation is less clear.

METHODS

This prospective nonrandomized study including adult patients was performed between October 2000 and April 2003. Two groups of immunosuppressive regimens were compared: group A received 2 g of methylprednisolone intraoperatively followed by a rapid reduction with intention to withdraw by month 4, continuing on Neoral monotherapy. Cellcept was also given for 2 months in the absence or for up to 4 months in the presence of rejection. Group B received the same immunosuppressive regimen but, in addition, daclizumab 1 to 1.5 mg/kg on day 1 and day 5 posttransplant. Rejection diagnosis is made on histology basis. Protocol biopsies were performed in all the patients on day 7 and if indicated by biochemistry thereafter.

RESULTS

Both groups were similar in terms of preoperative CHILD score, serum creatinine, incidence of status I, donor and recipient age and ischemia times. The mean follow-up time was 20 months for Group B (n = 24) and 7 months for Group A (n = 10). The 1-month and 1-year rejection rates are 29.1% and 41% in Group A versus 20% and 30% in group B. Rejection severity was similar between both groups. One-year patient and graft survival rates were 96% and 92% in group A and 100% for both in Group B.

CONCLUSIONS

In this series, daclizumab induction therapy seems to display a trend toward a lower rejection rate without increasing infectious complications nor affecting graft survival rates.

Fungal Infections in Solid Organ Transplant Patients

BACKGROUND

Solid organ transplantation is becoming increasingly more common in the treatment of end-stage organ failure. Opportunistic fungal infections are a frequent life-threatening complication of transplantation.

MATERIALS AND METHODS

In this article, a review of the infections in the different organ transplant recipients is presented.

RESULTS

The incidence of fungal infections in organ transplant patients ranges from 2% to 50% depending on the type of organ transplanted, kidney recipients being the least frequent and liver recipients having the highest rate of infection. New antifungal medications and immunosuppressants have changed the spectrum of fungal treatment and prevention.

CONCLUSION

Prompt recognition and treatment of infection is imperative for successful therapy. Further advancements in early detection and the development of less toxic medications will lead to refinements in the treatment of fungal infections.

Single-agent immunosuppression after liver transplantation: what is possible?

Orthotopic liver transplantation is a life saving and life enhancing procedure. The development of immunosuppressive drugs has contributed to the high rate of success in terms of both patient and graft survival. However, the considerable adverse effects of these therapies are affecting long-term outcomes of transplant recipients. Complications related to immunosuppression are responsible for the majority of deaths in patients surviving more than 1 year. Therefore, the search for an optimal immunosuppressive regimen has become of paramount importance. The liver has proved to be an 'immunologically privileged' organ, capable in several animal models to be accepted as an allograft without any intervention on the immune system of the recipient. In some human liver allografts acceptance of the new organ is recognised after withdrawal of immunosuppressants, but prior identification of such individuals is not yet possible, thus negating this management option. Graft-recipient interaction is peculiar in liver transplantation: acute cellular rejection does not always need to be treated, and if it is not severe, appears to be associated with a better survival of both patient and graft. In the last decade there has been an evolution of immunosuppressive protocols, driven by empirical observation and a deeper understanding of immunological events after transplant. However, most modifications have been made because of the necessity to reduce long-term drug related morbidity and mortality. Withdrawal of corticosteroids has proven to be safely achievable in most patients, with no deleterious effects on patient or graft survival but with a great benefit in terms of reduction of incidence of metabolic and cardiovascular complications. Long-term 'steroid-free' regimens are therefore now widely used. Patients with stable graft function can be easily maintained using a single drug usually after 6 or 12 months and usually with a calcineurin inhibitor. The more evolved step of using monotherapy ab initio has also proven to be effective in a few studies and needs to be explored further. In the future new strategies will be designed to help the development of tolerance of the allograft, selectively stimulating instead of suppressing the immune reaction of the recipient.

Options for induction immunosuppression in liver transplant recipients

Immunosuppression administered in the early postoperative period following liver transplantation plays a crucial role in the survival of the graft and the patient. The introduction of cyclosporin was an important landmark in transplantation, and to this day, calcineurin inhibitors form the basis of most induction immunosuppression regimens. New drugs are being developed which are more specifically targeted to prevention of rejection, and multiple drug combinations have been proposed as a means of reducing the adverse effects of individual drugs. Azathioprine and the newer antimetabolite mycophenolate mofetil have been added to calcineurin inhibitor-based regimens with varying amounts of success. Antibody induction has evolved as a potent form of immunosuppression as well as a means of avoiding certain adverse effects, particularly nephrotoxicity. The numerous adverse effects encountered with polyclonal preparations have been reduced with the development of more specific monoclonal antibodies such as muromonab CD3 (OKT3) or interleukin (IL)-2 receptor (IL-2R) antagonists. The anti-IL-2R antibody preparations basiliximab and daclizumab have shown excellent early results due to their potent yet highly targeted immunosuppressive effect and minimal adverse effects. Further study is needed to determine the most appropriate dosage, timing and patient population for these new drugs in the setting of liver transplantation. Although a number of different induction regimens have been described, no single protocol is suitable for all liver transplant recipients. Rather, certain regimens have advantages that could favour their use in a specific subgroup of patients. A number of clinical trials are underway to identify new, more specific drugs and combinations which could be useful in induction immunosuppression.

Long-term safety, tolerability and efficacy of daclizumab (Zenapax) in a two-dose regimen in liver transplant recipients

A major thrust of transplantation research is to find more effective and less broadly toxic immunosuppressive agents. One potential way is the use of monoclonal antibodies directed to IL-2R alpha. Immunoprophylaxis with daclizumab, a humanized anti-IL-2R alpha monoclonal antibody, has been shown to be effective in the prevention of acute rejection in kidney transplant patients. These results encouraged us to initiate a pilot study in 28 liver transplant patients in 1997. Daclizumab was administered intravenously approximately 6 h after reperfusion (1 mg/kg) and on day 4 post-transplant (0.5 mg/kg). Additional immunosuppression consisted of cyclosporine A as well as of corticosteroids. Administration of daclizumab was not associated with any side-effects. We only experienced one acute rejection in a patient on day 17 post-transplant. It resolved immediately under therapy with prednisolone. The rate of opportunistic infections did not differ from results with conventional immunosuppressive regimens. At 4 years post-transplant no lymphoproliferative disease was observed. Patient survival at 12, 24, 36 and 48 months post-transplant was 88.5, 84.6, 80.8 and 73.1%, respectively. Immunoprophylaxis with a two-dose daclizumab regimen is safe, effective and well tolerated, and does not lead to increased opportunistic infections.

Anti-interleukin-2 receptor therapy in combination with mycophenolate mofetil is associated with more severe hepatitis C recurrence after liver transplantation

The pathogenesis of hepatitis C virus (HCV) recurrence after liver transplantation (LT) is poorly understood, but the cellular immune response is likely to have a major role. Daclizumab, an interleukin-2 receptor (IL-2R) antibody that blunts T-cell activation, leading to a decreased risk for cellular rejection, is used frequently in transplant recipients. The aim of this study is to evaluate the effect of daclizumab therapy on the incidence and severity of recurrent HCV. Forty-one liver transplant recipients (21 patients, HCV positive; 20 patients, HCV negative) at high risk for neurological or renal complications of calcineurin inhibitors were administered daclizumab, mycophenolate mofetil (MMF), and steroids in the early post-LT period, followed by tacrolimus and a steroid taper. All patients were followed up prospectively for graft function and disease recurrence with protocol liver biopsies day 7, month 4, and yearly. Compared with patients without HCV, patients with HCV administered daclizumab had greater 4-month serum alkaline phosphatase, total bilirubin, and alanine aminotransferase (ALT) levels. These biochemical differences resolved by 12 months, except for persistent elevation of ALT levels. Compared with a well-matched HCV control population, patients with HCV administered daclizumab were more likely to have an earlier onset of hepatitis, jaundice, and greater histological activity. Recurrent hepatitis progressed more rapidly in the daclizumab group; 45% developed advanced disease within 1 year. HCV viral load in the daclizumab group was significantly greater at both 4 months and 1 year. Results of this study suggest that the use of adjuvant IL-2R antibodies in combination with MMF in the early peritransplantation period may be associated with early recurrence of hepatitis C and more rapid histological progression of disease.

Perioperative management of liver transplantation patients

Perioperative care involves many disciplines, each of which contributes in important ways. Changes in liver-transplantation care during the last 40 years can be attributed to the accumulation of improvements, discoveries, and technologic improvements across different disciplines. Here we review some of the articles that were published during the last year that relate to these advances.