Daclizumab: a review of its use in the management of organ transplantation

Immunoprotection of cellular transplants for autoimmune type 1 diabetes through local drug delivery

Type 1 diabetes mellitus (T1DM) is an autoimmune condition that results in the destruction of insulin-secreting β cells of the islets of Langerhans. Allogeneic islet transplantation could be a successful treatment for T1DM; however, it is limited by the need for effective, permanent immunosuppression to prevent graft rejection. Upon transplantation, islets are rejected through non-specific, alloantigen specific, and recurring autoimmune pathways. Immunosuppressive agents used for islet transplantation are generally successful in inhibiting alloantigen rejection, but they are suboptimal in hindering non-specific and autoimmune pathways. In this review, we summarize the challenges with cellular immunological rejection and therapeutics used for islet transplantation. We highlight agents that target these three immune rejection pathways and how to package them for controlled, local delivery via biomaterials. Exploring macro-, micro-, and nano-scale immunomodulatory biomaterial platforms, we summarize their advantages, challenges, and future directions. We hypothesize that understanding their key features will help identify effective platforms to prevent islet graft rejection. Outcomes can further be translated to other cellular therapies beyond T1DM.

Basiliximab With Delayed Tacrolimus Improves Short-Term Renal Outcomes Post-Liver Transplantation-a Real-World Experience

BACKGROUND

Acute kidney injury (AKI) is common after liver transplantation (LT). Induction with interleukin-2 receptor antagonists is often used as a "renal-sparing" strategy. The aim of this study was to assess this approach in a real-world setting in an LT center.

METHODS

A retrospective cohort analysis of LTs between 2011 and 2018 was performed to assess the impact of a renal-sparing strategy using basiliximab in conjunction with mycophenolate mofetil and corticosteroids from day 0 post-LT along with delayed introduction of tacrolimus. This was compared with a group receiving tacrolimus, mycophenolate mofetil, and corticosteroids from the outset.

RESULTS

The renal-sparing regimen was associated with significantly lower incidence of all-stage AKI at day 7 post-LT (36% vs 55%, P = .006) and less decline in renal function at 3 months (39% vs 57%, P = .01). No further significant differences in renal outcomes were observed at other time points on follow-up to 1 year post-LT. There was no significant difference in the incidence of acute cellular rejection, inpatient length of stay or graft survival. The decision to adopt a renal-sparing regimen was predominantly made on a clinically reactive basis within the first 24 hours post-LT in 77%, and was preordained in 23%. Cost-effectiveness analysis did not find evidence of a significant cost saving when using a renal-sparing strategy.

CONCLUSION

This study provides real-world analysis of the use of a renal-sparing immunosuppression regimen in LT. Although improvements in incidence of AKI in the short term were demonstrated, this did not translate to cost savings or improved renal outcomes after 3 months.

Antibody immunosuppressive therapy in solid-organ transplant: Part I

Currently, a wide variety of both polyclonal and monoclonal antibodies are being routinely utilized to prevent and treat solid organ rejection. More commonly, these agents are also administered in order to delay introduction of calcineurin inhibitors, especially in patients with already compromised renal function. While these antibody therapies dramatically reduced the incidence of acute rejection episodes and improved both short and long-term graft survival, they are also associated with an increased incidence of opportunistic infections and neoplastic complications. Therefore, effective patient management must necessarily balance these risks against the potential benefits of the therapy.

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.

Extended daclizumab monotherapy for rejection-free survival in non-adherent adolescent recipients of renal allografts

Acute rejection episodes are almost inevitable in the face of immunosuppression non-adherence and a known risk factor for developing chronic allograft nephropathy and accelerated graft loss. Daclizumab, a humanized monoclonal antibody directed against the alpha chain of the IL-2 receptor, is an important advance for induction therapy in renal transplant immunosuppression, reducing early acute graft rejection without affecting the tolerability of standard immunosuppression, for both steroid-based and steroid-free immunosuppressive protocols, in children and adults. In the absence of depot immunosuppression for maintenance therapy, we explored extended daclizumab therapy as temporary maintenance immunosuppression for acute rejection prophylaxis in two patients with recalcitrant immunosuppression non-adherence. Both patients had prior episodes of aggressive acute rejection associated with their non-adherence but achieved stable and rejection-free renal allograft function with daclizumab monotherapy in the presence of documented non-adherence thus providing an effective bridge for up to 12 months until immunosuppression adherence was re-established with ongoing psychosocial support. This report suggests that daclizumab monotherapy over an extended period of time during the period of non-adherence in the post transplant period could be a rescue modality to avoid immune activation and thereby prevent acute rejection in the face of erratic maintenance immunosuppression.

A double-masked, randomized study to investigate the safety and efficacy of daclizumab to treat the ocular complications related to Behçet's disease

PURPOSE

To investigate the safety and efficacy of daclizumab (Zenapax, humanized anti-Tac, HAT) in controlling the ocular manifestations of Behçet's disease.

DESIGN

Randomized, placebo-controlled, double-masked clinical trial.

PARTICIPANTS

Seventeen participants with Behçet's disease experiencing at least two prior ocular attacks and requiring treatment with immunosuppressive agents for the ocular complications of Behçet's disease.

METHODS

Participants received either intravenous placebo or daclizumab (1 mg/kg) infusions every two weeks for six weeks, then every four weeks while continuing their standard immunosuppressive regimens. If clinically indicated, tapering of the standard immunosuppressive medications was allowed after six months of study enrollment. Complete ocular and physical examinations and an adverse event assessment were performed at baseline and prior to each study infusion.

MAIN OUTCOME MEASURES

Primary safety endpoints were the development of a life-threatening complication or a severe opportunistic infection. Primary efficacy outcomes were the number of ocular attacks and an assessment of systemic immunosuppressive medications required during the study, including the ability to taper concomitant immunosuppressive therapy.

RESULTS

Nine participants randomized to daclizumab and eight to placebo were followed monthly. Follow-up ranged from one to 34 months, with a median follow-up of 15 months. Two participants randomized to daclizumab discontinued study therapy prior to the end of the study for personal reasons. No participant experienced a safety endpoint, and visual acuity remained stable in all participants during the course of the study. Ten participants (six daclizumab, four placebo) experienced ocular attacks requiring therapy. The median ocular attack rate during the study was greater in the daclizumab arm than the placebo arm (median 1.27 vs. 0.17 attacks/year, respectively). Participants in the placebo arm also experienced a greater reduction in the immunosuppressive medication score compared to participants receiving daclizumab (median -4.0 vs. -1.0, respectively).

CONCLUSIONS

The observed results in the placebo group demonstrate that careful follow-up and treatment with standard combination immunosuppressive therapy can be effective for the management of the ocular complications of Behçet's disease. In our small study, there was no suggestion that daclizumab was beneficial in comparison with placebo. However, the low observed attack rate limited our ability to make a definitive treatment group comparison.

Anti-Tac (daclizumab, Zenapax) in the treatment of leukemia, autoimmune diseases, and in the prevention of allograft rejection: a 25-year personal odyssey

Twenty-five years ago, we reported the production of the monoclonal antibody, anti-Tac that identifies the IL-2 receptor alpha subunit and blocks the interaction of IL-2 with this growth factor receptor. In 1997, daclizumab (Zenapax), the humanized form of this antibody, was approved by the FDA for use in the prevention of renal allograft rejection. In addition, we demonstrated that daclizumab is of value in the treatment of patients with noninfectious uveitis, multiple sclerosis, and the neurological disease human T-cell lymphotropic virus I associated myelopathy/tropical spastic paraparesis (HAM/TSP). Others demonstrated therapeutic efficacy with daclizumab in patients with pure red cell aplasia, aplastic anemia, and psoriasis. Thus, translation of basic insights concerning the IL-2/IL-2 receptor system obtained using the monoclonal antibody daclizumab provided a useful strategy for the prevention of organ allograft rejection and the treatment of patients with select autoimmune diseases or T-cell leukemia/lymphoma.

Drugs, their targets and the nature and number of drug targets

What is a drug target? And how many such targets are there? Here, we consider the nature of drug targets, and by classifying known drug substances on the basis of the discussed principles we provide an estimation of the total number of current drug targets.

Signaling T-cell survival and death by IL-2 and IL-15

Interleukin 2 (IL-2) and interleukin 15 (IL-15) bind to common T-cell surface receptors comprised of unique alpha (IL-2R alpha or IL-15R alpha) and shared beta/gamma chain subunits. Ligation of this receptor by IL-2 can lead to apoptosis whereas IL-15 ligation favors cell survival. Our study examined intra-cellular signaling events associated with IL-2- and IL-15-induced apoptosis and survival in human T cells. We found IL-2 and IL-15 could both induce apoptosis and survival; the outcome depended on cytokine concentration. No qualitative differences in Jak/Stat, Ras/MAPK or PI3K/AKT signaling were seen over a wide range of IL-2 and IL-15 concentrations. These findings suggest that, like T-cell receptor signaling, IL-2R beta/gamma chain signaling is regulated, or "tuned," by the concentration of cytokine.

Daclizumab to prevent rejection after cardiac transplantation

BACKGROUND

Daclizumab, a humanized monoclonal antibody against the interleukin-2 receptor, reduced the risk of rejection without increasing the risk of infection among renal-transplant recipients and, in a single-center trial, among cardiac-transplant recipients. We conducted a multicenter, placebo-controlled, double-blind study to confirm these results in cardiac-transplant patients.

METHODS

We randomly assigned 434 recipients of a first cardiac transplant treated with standard immunosuppression (cyclosporine, mycophenolate mofetil, and corticosteroids) to receive five doses of daclizumab or placebo. The primary end point was a composite of moderate or severe cellular rejection, hemodynamically significant graft dysfunction, a second transplantation, or death or loss to follow-up within six months.

RESULTS

By six months, 104 of 218 patients in the placebo group had reached the primary end point, as compared with 77 of the 216 patients in the daclizumab group (47.7 percent vs. 35.6 percent, P=0.007), a 12.1 percent absolute risk reduction and a 25 percent relative reduction. The rate of rejection was lower in the daclizumab group than in the placebo group (41.3 percent vs. 25.5 percent). Among patients reaching the primary end point, the median time to the end point was almost three times as long in the daclizumab group as in the placebo group during the first 6 months (61 vs. 21 days) and at 1 year (96 vs. 26 days). More patients in the daclizumab group than in the placebo group died of infection (6 vs. 0) when they received concomitant cytolytic therapy.

CONCLUSIONS

Daclizumab was efficacious as prophylaxis against acute cellular rejection after cardiac transplantation. Because of the excess risk of death, concurrent or anticipated use of cytolytic therapy with daclizumab should be avoided.

Corticosteroid-free immunosuppression with tacrolimus, mycophenolate mofetil, and daclizumab induction in renal transplantation

BACKGROUND

Corticosteroid-free maintenance immunosuppression after organ transplantation eliminates the well-known corticosteroid-related side effects and may help to improve long-term outcome. We investigated whether a corticosteroid-free tacrolimus (Tac)/mycophenolate mofetil (MMF) regimen, in combination with daclizumab (Dac) induction therapy, provides adequate immunosuppression after renal transplantation.

METHODS

This 6-month, open-label, multicenter, parallel-group study involved 538 renal patients randomized (1:1) to a Dac/Tac/MMF regimen (n = 260) or a Tac/MMF/corticosteroids regimen (n = 278) as a control group.

RESULTS

Of the patients who completed the study, 88.8% in the Dac/Tac/MMF group were free from corticosteroid therapy at month 6. The incidence of biopsy-proven acute rejection was 16.5% in both treatment groups; the incidence of biopsy-proven corticosteroid-resistant acute rejection was 4.3% and 5.0% with Tac/MMF/corticosteroids and Dac/Tac/MMF, respectively (P = NS for both comparisons). Renal function was also similar in both groups: median serum creatinine at month 6 was 125.0 micromol/L (Tac/MMF/corticosteroids) and 131.0 microml/L (Dac/Tac/MMF), P = 0.277. The overall safety profile was similar with both regimens. However, compared with the Tac/MMF/steroid regimen, a significantly reduced incidence of new-onset insulin-dependent diabetes mellitus (5.4% vs. 0.4%, P = 0.003) was found with steroid-free immunosuppression. Moreover, mean total cholesterol concentrations increased from baseline in the Tac/MMF/corticosteroids group by 0.19 mmol/L, whereas in the Dac/Tac/MMF group, levels decreased by 0.19 mmol/L, P = 0.005.

CONCLUSIONS

Corticosteroid-free immunosuppression with a Dac/Tac/MMF regimen is as effective at preventing acute rejection after renal transplantation as a standard triple regimen of Tac/MMF/corticosteroids. Furthermore, the safety benefits reported with Dac/Tac/MMF treatment may help improve the long-term outcome for renal-transplant patients.

Induction therapy after cardiac transplantation: A comparison of anti-thymocyte globulin and daclizumab in the prevention of acute rejection

BACKGROUND

Induction therapy with antibodies decreases and delays early allograft rejection. We compared the safety and efficacy of daclizumab and anti-thymocyte globulin (ATG) with respect to the frequency and severity of acute cardiac allograft rejection in heart transplant recipients.

METHODS

Forty sequential adult patients were retrospectively studied. In the first 20 patients ATG (2.5 mg/kg daily for 3 to 5 days peri-/and post-operatively) was used as induction therapy and, in the remaining 20 patients, daclizumab (1 mg/kg peri-operatively and every 2 weeks thereafter for a total of 5 doses) was used. A standard triple-drug immunosuppression regimen was administered to all patients.

RESULTS

Baseline characteristics and trough levels of cyclosporine in the 2 groups were similar. During the induction period, defined as the first 3 months, 12 acute rejection episodes requiring treatment (ISHLT Grade > or =2) occurred in the ATG group and 9 in the daclizumab group (p > 0.05). However, the number of biopsies with Grade 1 rejection was increased >2-fold in the daclizumab group (n = 35) compared with the ATG group (n = 17; p = 0.04). The total number of biopsies performed within the first 3 months increased by 26% in the daclizumab group. The number and severity of rejection episodes after 3 months was similar in the 2 groups. The overall occurrence of bacterial infections was significantly higher in the ATG group than in the daclizumab group (p = 0.05).

CONCLUSIONS

ATG and daclizumab are equally effective in preventing acute rejections requiring treatment (ISHLT Grade > or =2). Due to the significantly greater frequency of Grade 1 rejections, daclizumab was found to be associated with an increased number of additional biopsies for monitoring rejection status. This implies additional costs to the transplant program, and the long-term implications of the increased number of low-grade rejection episodes remains to be determined.

Corticosteroid-free immunosuppression with tacrolimus following induction with daclizumab: a large randomized clinical study

This open, randomized (1 : 1), multicenter, 3-month study compared a dual tacrolimus plus steroids (Tac / steroids) regimen with a steroid-free immunosuppressive regimen of tacrolimus following daclizumab induction therapy (Tac / Dac) in adult liver transplant recipients. The full analysis set comprised 347 patients in the Tac / steroids group and 351 in the Tac / Dac group. Mean tacrolimus dose during month 3 was 0.11 mg/kg/day in both groups; mean whole-blood trough levels during month 3 were 10.9 ng/mL (Tac / steroids) and 10.6 ng/mL (Tac / Dac). The incidence of biopsy-confirmed acute rejection that required treatment was similar in both groups: 26.5% in the Tac / steroids group and 25.4% in the Tac / Dac group (P = .727). However, the incidence of biopsy-confirmed corticosteroid-resistant acute rejection was higher in the Tac / steroids group than in the Tac / Dac group (6.3 vs. 2.8%; P = .027). Kaplan-Meier estimates of graft survival (92.2 vs. 90.5%) and patient survival (94.5 vs. 93.7%) were similar in both groups. While also the overall adverse event profiles were similar, the incidences of diabetes mellitus (15.3 vs. 5.7%, respectively; P < .001) and cytomegalovirus infection (11.5 vs. 5.1%, respectively; P = .002) were higher in the Tac / steroids group compared with the Tac / Dac group. Mean cholesterol levels increased by 16% in the Tac / steroids group, but were unchanged in the Tac / Dac group during the study. In conclusion, tacrolimus monotherapy following daclizumab induction is an effective and safe regimen, with an advantage over concomitant steroid-maintenance therapy in terms of a lower incidence of diabetes and viral infection, and a lower incidence of steroid-resistant acute rejection.

Efficacy and Safety of Basiliximab with a Tacrolimus-Based Regimen in Liver Transplant Recipients

BACKGROUND

Induction with monoclonal antibodies for prevention of acute cellular rejection (ACR) may avoid many of the adverse events associated with polyclonal antibodies. Basiliximab, a chimeric monoclonal antibody directed against the alpha-chain of the interleukin 2 receptor (CD25), has been extensively evaluated as an induction therapy for kidney transplant recipients, more frequently in combination with a cyclosporine-based regimen. In this study, we assessed the efficacy and safety of basiliximab in combination with a tacrolimus-based regimen after liver transplantation.

METHODS

Fifty consecutive liver transplants (47 cadaveric donors; 3 living donors) were analyzed. All patients received two 20-mg doses of basiliximab (days 0 and 4 after transplantation) followed by tacrolimus (0.15 mg/kg/day; 10-15 ng/mL target trough levels) and a tapered dose regimen of steroids. Follow-up ranged from 404 to 1,364 days after transplantation (mean 799.89 days, SD+/-257.37; median 796 days).

RESULTS

A total of 88% of patients remained rejection-free during follow-up with an actuarial rejection-free probability of 75% within 3 months. The actuarial patient survival rate at 3 years was 88%, and the graft survival rate was 75%. Twelve (24%) patients experienced one episode of sepsis, requiring temporary reduction of immunosuppressive therapy. There were no immediate side effects associated with basiliximab and no evidence of cytomegalovirus infection or posttransplant lymphoproliferative disorder.

CONCLUSIONS

Basiliximab in combination with a tacrolimus-based immunosuppressive regimen is effective in reducing episodes of ACR and increasing ACR-free survival after liver transplantation. In addition, basiliximab does not increase the incidence of adverse effects or infections.

Management of immune thrombocytopenic purpura in adults

Primary immune thrombocytopenic purpura (ITP), also referred to as idiopathic thrombocytopenic purpura, is an organ-specific autoimmune disorder in which antibody-coated or immune complex-coated platelets are destroyed prematurely by the reticuloendothelial system, resulting in peripheral blood thrombocytopenia. The disease is heterogeneous with regard to its severity and clinical course and is unpredictable in its response to therapy. Although the basic underlying pathophysiology of ITP has been known for more than 50 years, current treatment guidelines are based on expert opinion rather than on evidence because of a lack of high-quality clinical trials and research. The only patients for whom treatment is clearly required are those with severe bleeding and/or extremely low platelet counts (< 10 x 10(9)/L). Treatment of patients with ITP refractory to corticosteroids and splenectomy requires careful evaluation of disease severity, patient characteristics related to risk of bleeding, and adverse effects associated with treatment. Clinical trials with numerous new agents are under way, which we hope will add more effective and targeted strategies to our therapeutic armamentarium. We describe a logical and structured approach to the clinical management of ITP in adults, based on a literature review and our personal experience.

Pharmacokinetics of daclizumab and mycophenolate mofetil with cyclosporine and steroids in renal transplantation

Daclizumab and mycophenolate mofetil (MMF) decrease the incidence of acute allograft rejection. This double-blind, randomized, placebo-controlled trial was performed primarily to assess the pharmacokinetics of MMF in an immunosuppressive regimen incorporating daclizumab. At five centers, 75 renal transplant recipients were randomized 2:1 to receive either daclizumab 1 mg/kg or placebo pre-transplantation and every other week, for a total of five doses. All patients received cyclosporine, steroids, and MMF. Levels of mycophenolic acid (MPA), its glucuronide metabolite, and daclizumab were measured after dosing on days 28 and 56. Safety parameters evaluated included: adverse events, laboratory abnormalities, infections, patient/graft survival, incidence of lymphoproliferative disorders, and incidence of acute rejection at 12 months. The concomitant administration of daclizumab and MMF had no effect on the pharmacokinetics of MPA: AUC(0-8) values (microg h/mL +/- SD) on day 28 were 30.1 +/- 13.3 for daclizumab-treat patients vs. 31.1 +/- 12.4 for placebo and on day 56, 37.7 +/- 18.2 for daclizumab-treated patients vs. 35.7 +/- 14.0 for placebo. Adverse events were similar between the two groups. Acute rejection at 12 months occurred in 14% of patients receiving daclizumab and 20% of patients receiving placebo. The coadministration of daclizumab did not result in a pharmacokinetic interaction with MPA, the active metabolite of MMF.

Recombinant humanized anti-IL-2 receptor antibody (daclizumab) produces responses in patients with moderate aplastic anemia

In contrast to severe aplastic anemia (sAA), the appropriate management of patients with moderate pancytopenia is unclear. In this study, we examined the efficacy of a humanized monoclonal antibody recognizing interleukin-2 receptor (daclizumab), which has proven to be a successful immunosuppressive agent in solid organ and bone marrow transplantation. We treated 17 patients with moderate aplastic anemia (mAA) with 1 mg/kg every 2 weeks for 3 months. mAA was defined as depression of 2 of the 3 blood counts: absolute neutrophil count 1200/mm3 or less, platelet count 70,000/mm3 or less, hemoglobin level 8.5 g/dL or lower, and absolute reticulocyte count 60,000/mm3 or less. The primary end point of our protocol was a hematologic response in at least one affected peripheral blood value. Daclizumab had little toxicity. Six of the 16 (38%) evaluable patients responded to treatment. Two patients with previously chronic disease showed complete return of normal counts, which were sustained for more than 2 years following treatment. Four patients had single-lineage responses. Two previously transfusion-dependent patients became transfusion independent; one patient with many neutropenia-related infections had a normal neutrophil count following treatment. Daclizumab appears safe; its efficacy in this pilot protocol suggests that expanded study of this monoclonal antibody in immune-mediated bone marrow failure syndrome is warranted.

Single-dose daclizumab induction therapy in patients with liver transplantation

AIM: To investigate the efficacy and safety of a single-dose daclizumab induction therapy in orthotopic liver transplantation (OLTx).

METHODS: A retrospective study was made for 54 cases of OLTx in recent three years. The daclizumab group consisted of 23 cases of OLTx who received single-dose of 2 mg/kg intravenously after postoperative 24 hours. The control group consisted of the remaining 31 patients. Additional immunosuppressors included steroids, mycomphenolate mofetil, facrolimus or microemulsion cyclosporine used in all patients. Meta-statistical analysis was made for general data, incidence of acute rejection and infection, postoperative clinical course, complications and prognosis between two groups.

RESULTS: Pretransplant demographies were not significantly different between two groups. In the induction group there were significantly less acute rejection episodes (5 of 23, 21.74%) than those in the control group (12 of 31, 38.71%), which were proved by pathologic diagnosis (P < 0.05). The incidence of infection at the early stage was not significantly different between two groups.

CONCLUSION: Induction therapy with single-dose of daclizumab is safe and effective and appears to be able to reduce the incidence of acute rejection.

Treatment targeted to cell surface epitopes

Expression of a variety of surface epitopes is a characteristic feature of immune cells. Receptors and adhesion molecules are the most predominant ones. It is also characteristic that epitope expression is modulated during cellular activation. In inflammatory skin diseases these structures can be used to define not only the type of cell but also their activity status. The availability of monoclonal antibodies and fusion proteins enabled to target cellular surface epitopes in order to modulate the cellular function as a principle of treatment. In psoriasis receptor-targeted therapy has been developed and tested in a considerable number of clinical trials. However, these approaches revealed that not all the strategies are equally effective. In this review the development of receptor-targeted treatment for skin disorders, mainly psoriasis, is described. Clinical as well as experimental data obtained with the various compounds employed are discussed with regard to clinical efficacy, safety and tolerability.

Evolving new therapies of autoimmune hepatitis

Refinements in the understanding of the mechanisms of immunocyte activation and the emergence of new immunosuppressive agents with highly selective actions has created opportunities for improving the treatment of autoimmune hepatitis. Drugs, such as budesonide and deflazacort, may inhibit immunocyte activation and limit corticosteroid-related side effects. Agents, such as cyclosporine and tacrolimus, can impair calcineurin activity and restrict the generation of transcription factors necessary for T cell responses. Intravenous immunoglobulin can bind anti-idiotype antibodies and reduce interleukin-2 secretion, and monoclonal antibodies directed against critical components of the T cell activation cascade can dampen the immune reaction. Drugs, such as mycophenolate mofetil, cyclophosphamide, methotrexate, and KF20444, can inhibit T cell proliferation, and other interventions promise to deplete activated T cells, impair effector mechanisms, and induce self-tolerance.

Current practices: immunosuppression induction, maintenance, and rejection regimens in contemporary post-heart transplant patient treatment

Cardiac transplantation is the definitive treatment for eligible patients with end-stage cardiomyopathy. Survival rates have improved dramatically during the last 10 years, especially since the advent of cyclosporine-A. Cardiac allograft rejection, previously considered a major cause of early mortality after transplantation, is no longer the limiting factor for early survival, with the use of newer and more specific immunosuppression regimens. Very few randomized, prospective trials, including comparisons between immunosuppression regimens, have been conducted in this area. Therefore, practices vary with physician and institutional experience. Most centers use a multipronged approach to immunosuppression, targeting multiple sites in the immune cascade that lead to allograft rejection. Multiple new agents in development are reviewed. Drugs such as sirolimus and its derivative, everolimus, act on specific intracellular receptors within lymphocytes, whereas other medications such as Daclizumab (Roche Laboratories, Nutley, NJ) block the interleukin-2 receptor on the surface of activated T cells. The immune response to foreign antigens is complex, with multiple redundant levels. Immunosuppression regimens continue to seek a fine balance between overimmunosuppression and insufficient protection, which may lead to allograft rejection or loss.