ALG treatment of steroid-resistant rejection in patients receiving cyclosporine

Overview of immunosuppression in liver transplantation

Continued advances in surgical techniques and immunosuppressive therapy have allowed liver transplantation to become an extremely successful treatment option for patients with end-stage liver disease. Beginning with the revolutionary discovery of cyclosporine in the 1970s, immunosuppressive regimens have evolved greatly and current statistics confirm one-year graft survival rates in excess of 80%. Immunosuppressive regimens include calcineurin inhibitors, anti-metabolites, mTOR inhibitors, steroids and antibody-based therapies. These agents target different sites in the T cell activation cascade, usually by inhibiting T cell activation or via T cell depletion. They are used as induction therapy in the immediate peri- and post-operative period, as long-term maintenance medications to preserve graft function and as salvage therapy for acute rejection in liver transplant recipients. This review will focus on existing immunosuppressive agents for liver transplantation and consider newer medications on the horizon.

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.

Kidney transplantation in the elderly: a decision analysis

Transplantation offers superior life expectancy and quality of life compared with dialysis in young patients with end-stage renal failure. However, the initial risks of mortality and morbidity are high. This study used a decision analysis model to evaluate the costs and benefits of kidney transplantation versus continued dialysis for older patients with renal failure. A decision analytic model comparing cadaveric renal transplantation to continued hemodialysis treatment was developed. The base case considered a theoretical cohort of patients aged 65 yr without known comorbidity or contraindications to transplantation who would have to wait 2 yr for a cadaveric transplant. Separate models were constructed for patients with diabetes or cardiovascular disease and for patients receiving an organ after a variety of wait-list times. Probability, utility, and survival data were obtained from published reports and renal registries. For 65-yr-old patients, quality-adjusted life expectancy increased by 1.1 quality-adjusted life years (QALY) at an incremental cost of $67,778 per QALY. Assuming a 2-yr wait-listed time, transplantation remained economically attractive for 70-yr-old patients (incremental cost effectiveness [ICE], $79,359 per QALY) but was less economically attractive for those over 75 yr of age (ICE, $99,553) or for 70-yr-olds with either cardiovascular disease or diabetes (ICE, $126,751 and $161,090 per QALY, respectively). The analytic results were sensitive only to the time spent waiting for the graft. The cost-effectiveness reduced such that the costs associated with one QALY were in excess of $100,000/yr when the probability of a complication was > or = 50% per 3-mo cycle and when the utility of transplantation fell below 0.62. If available within a timely period, transplantation may offer substantial clinical benefits to older patients at a reasonable financial cost. Prolonged waiting times dramatically decrease the clinical benefits and economic attractiveness of transplantation, suggesting that living donor transplantation may be of particular benefit in this population.

Contemporary immunosuppression in renal transplantation

Over the past 3 decades, renal allograft survival has improved significantly as a result of the development of powerful immunosuppressive agents. Nevertheless, the overall half-life of renal allografts has increased marginally during that time period, owing to drug-related nephrotoxicity and chronic rejection. New immunosuppressive agents are being evaluated because of the need for a reduction in the dose of nephrotoxic calcineurin inhibitors and corticosteroids. Additional agents have demonstrated the ability to retard the onset of chronic rejection in preclinical transplant models. In concert with these efforts, approaches are in development to alleviate the ever increasing shortage of donor organs, including the as yet unrealized goals of successful and practical xenotransplantation and the bioartificial kidney. Further identification and development of novel agents that target the specific components of the allograft response will provide the key to the achievement of donor-specific tolerance, the "Holy Grail" of solid organ transplantation.

Clinical application of immunosuppressive agents in renal transplantation

The availability of a number of new immunosuppressive drugs has resulted in significant improvements in the outcome of kidney transplantation. Currently 1-year graft survival rate for cadaver kidney transplants is approximately 85%. A number of new agents are presently in clinical studies. This article reviews the currently available agents and examines various aspects of induction and maintenance immunosuppressive therapy, and the treatment of acute rejection episodes. In addition, the agents currently in clinical trials and future directions in immunosuppressive therapy are discussed.

Timing of cyclosporine administration in patients with delayed graft function

Cyclosporine in renal transplant recipients with delayed graft function (DGF) has been reported to decrease graft survival and prolong both DGF and hospitalization. In some centers, antilymphocyte globulin (ALG) has been used perioperatively to obviate these problems, but ALG is associated with increased viral infections. In this study, first cadaver transplant recipients with a fall in serum creatinine level of greater than or equal to 30% in the first 24 hr were started on prednisone (P) and cyclosporine (Group 1, n = 18). Those whose creatinine level did not fall were started on P and azathioprine (Group 2, n = 23) and switched to P and cyclosporine when serum creatinine fell 30%. One-year patient survival was 98%. One-year graft survival was 83% for both Groups 1 and 2 (NS). Results were compared to historical controls with DGF who received P and cyclosporine (Group 3, n = 19). Patients with DGF and requiring dialysis had fewer dialyses (P less than 0.05) and a shorter hospital stay (P less than 0.05) if started on azathioprine, as compared to those started on cyclosporine. Patients with DGF had a higher serum creatinine at 12 months than those with immediate function (P less than 0.05). We conclude that withholding cyclosporine until DGF is resolving decreases the duration of dialysis, decreases hospital stay, and without the use of prophylactic ALG, is associated with graft survival equivalent to that in patients with immediate function.