Comparative evaluation of tacrolimus (Fk506) and cyclosporin a as immunosuppressive agents

Tacrolimus Eye Drops as Adjunct Therapy in Severe Corneal Endothelial Rejection Refractory to Corticosteroids

PURPOSE

To evaluate the safety and efficacy of tacrolimus eye drops as adjunctive therapy in the treatment of severe corneal endothelial rejection after penetrating keratoplasty refractory to corticosteroids.

METHODS

In this prospective interventional case series, 11 eyes of 11 patients assessed for severe corneal endothelial rejection, with an inadequate response to topical, local, and systemic corticosteroids, were treated with either 0.01% or 0.05% tacrolimus eye drops 4 times daily. Improvement in signs of rejection, visual function, and development of complications were monitored.

RESULTS

The duration of steroid treatment before intervention was 8.1 ± 1.4 days (range = 7-11). Patients were subsequently administered topical tacrolimus 0.01% or 0.05% qid. The time to clinical improvement was 10.3 ± 3.4 days (range = 3-17). The time to rejection reversal was 27.8 ± 16.3 days (range = 7-52). After 3 months, 10 patients (90.8%) demonstrated clinical improvement, and complete restoration of graft clarity was achieved in 5 patients (45.4%). In responsive cases, steroid therapy was successfully tapered off after 60.2 ± 19.7 days (range = 36-93). The best spectacle-corrected visual acuity improved from 1.7 ± 0.9 to 0.8 ± 0.5 logMAR (P = 0.0016). Reported side effects included stinging on drop instillation and punctate epithelial keratopathy.

CONCLUSIONS

Tacrolimus eye drops may be able to play an adjunctive therapeutic role in patients with severe corneal endothelial rejection refractory to conventional steroid treatment. Controlled studies are needed to further investigate the role of tacrolimus in this setting.

The efficacy and safety of cyclosporine reduction in de novo renal allograft patients receiving sirolimus and corticosteroids: results from an open-label comparative study

This study evaluated the safety and efficacy of a sirolimus, corticosteroid, and cyclosporine reduction regimen in an open-label, 12-month trial of 420 de novo renal allograft recipients at 49 European transplant centers. One month post-transplantation, 357 patients were randomized to receive standard-dose cyclosporine (sCsA, n = 179) or reduced-dose cyclosporine (rCsA, n = 178). All patients also received sirolimus and corticosteroids. The primary end points were the rate of biopsy-confirmed acute rejection (BCAR) and renal function, as measured by serum creatinine. Baseline demographic and donor characteristics were similar between groups. BCAR rates at 12 months were not significantly different: 11.2% for rCsA patients and 16.2% for sCsA patients. Mean serum creatinine (±SEM) was significantly lower (1.75 ± 0.10 vs. 1.97 ± 0.07 mg/dl, P < 0.001), and creatinine clearance (±SEM; Nankivell method) was significantly higher (57.8 ± 1.78 vs. 49.5 ± 2.46 ml/min, P < 0.001) in patients receiving rCsA versus sCsA at 1 year, respectively. Patient and graft survival exceeded 98% in both groups. No significant differences in infection or malignancy were noted between groups. The rCsA with sirolimus and corticosteroid regimen resulted in excellent 12-month patient and graft survival, a low incidence of BCAR, and improved renal function in renal allograft recipients. Sirolimus administered with rCsA and corticosteroids provided adequate immunosuppression while reducing the potential for the nephrotoxic effects of cyclosporine. These findings may help to improve long-term renal allograft outcomes.

Tacrolimus: 10 years of successful clinical application

Tacrolimus (FK506) is the first drug from the new class of drugs - calcineurin inhibitors. It has a great potential and can change the current approaches to treatment of different dermatoses. Topical forms of Tacrolimus are activated due to the effect on T-lymphocyte signal transduction, and they also inhibit gene transcription. As a result, the T-cell response to antigens is alleviated. Percutaneous absorption of Tacrolimus in affection foci is higher than in healthy skin. Due to this a smaller amount of the drug is absorbed by the skin as long as the skin is healed. Systemic absorption of Tacrolimus is low in the course of treatment. The maximum clinical experience has been gained in the field of applying Tacrolimus for treatment of atopic dermatitis. In a number of clinical studies, 0.03-0.3% Tacrolimus ointment efficiently reduced the severity of symptoms and course of atopic dermatitis in adults and children. Moreover, topical treatment with Tacrolimus did not involve any substantial toxic effects. The patients most often complained of local irritations in the area where the ointment was applied, which were transient by nature and did not demand the drug withdrawal. Today Tacrolimus is a valuable and safer alternative to glucocorticosteroids for treatment of atopic dermatitis. It can also be used for treating other dermatoses, which demands additional all-round examination.

Long term management of liver transplant rejection in children

The current management of hepatic allograft rejection after liver transplantation in children requires effective baseline immunosuppression to prevent rejection and rapid diagnosis and treatment to manage acute rejection episodes. The subsequent impact on chronic rejection is dependent on the combination of adequate prevention and the treatment of acute rejection. Tacrolimus is a macrolide lactone that inhibits the signal transduction of interleukin-2 (IL-2) via calcineurin inhibition. Introduced in 1989, tacrolimus was first used in the salvage of refractory acute or chronic rejection under cyclosporin or to rescue patients with significant cyclosporin-related complications. The majority of paediatric transplant centres use a combination of steroids with tacrolimus as a basic immunosuppressant regimen following paediatric liver transplantation. This combination has allowed the acute cellular rejection-free rate to increase to between 30 and 60%, while lowering the rate of refractory rejection to less than 5%. Corticosteroid-resistant rejection is commonly treated with monoclonal (muromonab CD3) or polyclonal preparations. Although most episodes of acute cellular rejection occur during the first 6 weeks after liver transplant, the appearance of late acute liver allograft rejection must raise the question of noncompliance, especially in the adolescent population. Chronic rejection is becoming increasingly rare under tacrolimus-based immunosuppression. Tacrolimus is effective in reversing refractory acute cellular rejection or early chronic rejection in patients initially treated with cyclosporin-based regimens. Patients with a history of noncompliance as well as children with autoimmune liver disease are at risk of chronic rejection. Retransplantation therapy for chronic rejection has, fortunately, become more rare in the tacrolimus era with only 3% of retransplants being performed for this indication. Newer immunosuppressive agents are further modifying the long term management of liver allograft rejection. These include mycophenolate mofetil, rapamycin and IL-2 antibodies such as daclizumab. The development of these agents is allowing patient-specific immunosuppressive management to minimise rejection as well as the complications related to immunosuppression.

Calcineurin inhibitors in renal transplantation: what is the best option?

Recently, new calcineurin inhibitors, such as tacrolimus (FK-506) and microemulsion cyclosporin, have been approved for maintenance immunosuppression in renal transplant recipients and short-term outcomes have been accumulating. In the majority of patients, these calcineurin inhibitors have been used in combination with new immunosuppressive drugs, such as mycophenolate mofetil (MMF) or sirolimus. Under these circumstances, a comparison of cyclosporin and tacrolimus provides the answer to a very important controversial issue. Which drug should we choose in individual patients? In an attempt to answer this question, this review compared the use of tacrolimus and cyclosporin in modern immunosuppressive regimens, which have already been published in well designed clinical studies, and discusses how immunosuppression should be individualised in renal transplant patients.Overall, short-term patient and graft survival with cyclosporin microemulsion and tacrolimus is almost identical. The incidence of acute rejection is generally lower in tacrolimus/azathioprine- than in cyclosporin/azathioprine-treated patients. However, in conjunction with MMF, the difference in the incidence of acute rejection between tacrolimus- and cyclosporin-treated patients became smaller. Adverse events, such as hypertension, hyperlipidaemia and cosmetic changes (gum hypertrophy, hirsutism) seem to be less frequent in tacrolimus-treated than in cyclosporin-treated patients. Recent randomised studies showed that the incidence of post-transplant diabetes mellitus was almost identical between low-dose tacrolimus- and cyclosporin-treated patients. According to the data discussed in this review, the recommendation on the choice of calcineurin inhibitors at this moment is that either cyclosporin or tacrolimus can be used safely and effectively for patients without any risk factors. However, at our centre, we prefer tacrolimus to cyclosporin in patients with a high risk for rejection, such as those with ABO-incompatibility, delayed graft function, sensitisation, and African American race and some other risk factors, such as hypertension and hyperlipidaemia. Moreover, tacrolimus may be preferable to cyclosporin for women because of hirsutism and for children because of the steroid-sparing effect. We consider that cyclosporin should be chosen when patients experience tacrolimus-related adverse events, such as severe chest pain, tremor, gastrointestinal symptoms and encephalopathy. In conclusion, well tolerated and effective immunosuppression is feasible with both cyclosporin and tacrolimus. In the current immunosuppressive regimens, a calcineurin inhibitor, either tacrolimus or cyclosporin, is the essential basic standard immunosuppressant. Clinicians need to decide the best means of optimising therapy for individual patients, based on various risk factors, such as risk of rejection, i.e. sensitisation, delayed graft function and ABO-incompatibility, and some adverse events, such as hypertension, hyperlipidaemia and cosmetic changes.

Conversion from cyclosporin to tacrolimus in paediatric liver transplant recipients

Substitution of cyclosporin with tacrolimus should be considered for paediatric liver transplant recipients with cyclosporin-associated complications such as hypertension, gum hyperplasia, hirsutism, gynaecomastia and growth retardation, as well as recurrent or refractory acute rejection, chronic duct injury or chronic rejection. Continued experience with well tolerated drug administration and careful monitoring during drug substitution has limited drug toxicity associated with tacrolimus to a level comparable to or less than that associated with cyclosporin. Successful outcome with long term graft salvage has been reported in up to 80% of patients converted to tacrolimus because of acute rejection and 50% of patients converted because of chronic rejection. Nearly all children converted because of cyclosporin-related complications have a successful outcome. Additional benefits of conversion to tacrolimus include improvement in growth and resolution of hypertension, hirsutism and cushingoid facies. Complete corticosteroid withdrawal is possible in up to 78% of children post-conversion. Long term outcome in these patients may be optimised by conversion to tacrolimus at an early stage of acute or chronic transplant rejection in order to minimise the cumulative amount of immunosuppression. Avoidance of cyclosporin-related toxicity and minimisation of corticosteroid therapy may further improve patient compliance to drug therapy.

Tacrolimus: a review of its use for the management of dermatoses

The newly developed immunomodulator tacrolimus (FK506) is the first of a new class of agents that have enormous potential to change the way that dermatoses are treated and managed. Tacrolimus has been found to be active in a topical formulation with the latter exerting its effects by acting on the signal transduction pathways inside T cells and inhibiting gene transcription. The result is decreased responsiveness of T cells to antigens. Percutaneous absorption of tacrolimus is higher in diseased skin as opposed to healthy skin and, therefore, the drug will be taken in at progressively lower quantities as lesions heal. There is limited systemic absorption of tacrolimus over the course of therapy. The most extensive experience with tacrolimus has been in treating atopic dermatitis. In numerous trials, tacrolimus ointment 0.03-0.3% has shown to be effective in reducing the symptoms and severity of atopic dermatitis in adults and the paediatric population. Furthermore, there have been no significant toxic effects associated with topical therapy with tacrolimus. The most common complaint is that of local irritation after applying the ointment. This is generally transient and the patient is able to continue with therapy. The other dermatoses where tacrolimus has been used include contact dermatitis, psoriasis and pyoderma gangrenosum.

Topical tacrolimus and pimecrolimus: future directions

Topical tacrolimus ointment and pimecrolimus cream represent the first members of a new class of medications. Topical immunomodulators have been developed for the treatment of atopic dermatitis. Their superb safety profiles and excellent efficacy as anti-inflammatory agents make them attractive candidates to treat a host of other skin disorders. This article reviews published experiences that use them for psoriasis, seborrheic dermatitis, lichen planus, pyoderma gangrenosum and other diseases. Possible modifications to these compounds and novel untested applications are discussed.

Immunosuppressive agents in transplantation: mechanisms of action and current anti-rejection strategies

Over the past century, the concept of interfering with the immune response at various sites by blocking the formation, stimulation, proliferation, and differentiation of lymphocytes has led to relentless development of new immunosuppressive drugs. These agents are associated with reduced risk of short- and long-term toxicity and have dramatically improved allograft and patient survival, especially in recipients of solid organ transplants. Current protocols in such patients are nearly all calcineurin-inhibitor based, using cyclosporine or tacrolimus, as part of dual, triple, or sequential therapy. This review focuses on agents currently in clinical use at transplant centers in United States. The drugs are described in terms of their basic mechanisms of action, therapeutic uses, clinical studies, and adverse effects. In addition, the efficacy and toxicity of a few promising new therapeutic approaches are examined. Finally, important challenges regarding pharmacological immunosuppression as it relates to solid organ and composite tissue allotransplantation are discussed.

Cardiovascular risk factors in renal transplant patients: cyclosporin A versus tacrolimus

The hypertensive and hyperlipidemic effects of cyclosporin A (CsA) may contribute to the high cardiovascular morbidity in renal transplant patients and to the development of chronic transplant nephropathy. Tacrolimus is reported to have less effect on BP and lipids, but steroids, other drugs, and renal function may confound this. This study assessed 24-h BP and lipid profile in stable renal transplant recipients (n = 17) while they were receiving CsA, after 4 wk of receiving tacrolimus, and again after 4 wk of receiving CsA. Antihypertensives were stopped at least 3 wk before. A few patients used low-dose steroids and lipid-lowering drugs, which were not changed during the study. Mean daytime BP decreased from 149 +/- 12 and 95 +/- 8 mmHg to 138 +/- 13 and 87 +/- 9 mmHg (P: < 0.001) after patients were switched to tacrolimus. Mean nighttime BP also decreased, from 140 +/- 12/86 +/- 7 mmHg to 132 +/- 17/79 +/- 10 mmHg (P: < 0.05). Total and low-density lipoprotein cholesterol decreased from 6.1 +/- 0.7 and 3.84 +/- 0.79 mmol/L to 5.1 +/- 0.8 and 2.98 +/- 0.75 mmol/L (P: < 0.001). Return to CsA caused an increase in BP and cholesterol to values similar as during the first CsA period. The conclusion is that tacrolimus has fewer unfavorable effects on BP and lipids than does CsA. Elective conversion from CsA to tacrolimus in stable renal transplant recipients may lead to attenuation of cardiovascular morbidity and chronic transplant nephropathy in the long term.

Rapamycin in transplantation: a review of the evidence

Rapamycin in transplantation: A review of the evidence. The calcineurin inhibitors have been the mainstays of immunosuppression for solid organ transplantation over the last two decades, but nephrotoxicity limits their therapeutic benefit. Rapamycin is a new drug with both immunosuppressant and antiproliferative properties that has a unique mechanism of action distinct from that of the calcineurin inhibitors. It has a role as a maintenance immunosuppressant either alone or in combination with a calcineurin inhibitor and can also be used to treat refractory acute rejection. Theoretical evidence suggests that it may limit the development and progression of chronic rejection in transplant recipients, but this has yet to be confirmed. This review examines the current in vitro animal and human work underlying the use of rapamycin and, in addition, comments on the pharmacokinetics and side-effect profile of this promising new agent.

Immunophilins may limit calcineurin inhibition by cyclosporine and tacrolimus at high drug concentrations

BACKGROUND

The immunosuppressive drugs cyclosporine (CsA) and tacrolimus (FK506 or FK) are qualitatively similar but differ in molar potency. Both drugs sterically inhibit the phosphatase activity of calcineurin (CN) but differ in molar potency. In our study we explored whether differential inhibition of CN explained the differences in molar potency of FK versus CsA.

METHODS

We compared their effects on NFATC2 dephosphorylation using Western analysis, interferon-gamma production using ELISA, and CN phosphatase activity using the CN assay in human peripheral blood leukocytes (PBL) and mouse spleen cell suspension.

RESULTS

The FK concentration inhibiting 50% (IC50) of all three activities was approximately 0.2 microg/ml in human PBL, versus 5-20 microg/ml for CsA. Although inhibition of interferon-gamma secretion and NFATC2 dephosphorylation was complete, inhibition of CN phosphatase activity was incomplete with both drugs at saturation, particularly with FK. Inhibition of CN phosphatase activity was incomplete whether FK treatment was in vivo in mouse or in vitro in various human and mouse tissues, especially brain. Exogenous FKBP12 or CyPA increased CN phosphatase inhibition, suggesting that incomplete inhibition of CN phosphatase activity reflected limiting amounts of active immunophilin.

CONCLUSIONS

These data contradict the prevailing assumption that immunophilins are abundant and not limiting for inhibition of CN by CsA or FK. Further, the observation that FK and CsA completely inhibit immune function without completely inhibiting CN suggests that the inhibition of immune function is not mediated by general CN inhibition but by inhibition of a subset of CN which is critical for lymphocyte activation.

Late-onset renal failure after liver transplantation: role of posttransplant alcohol use

BACKGROUND

Late-onset renal failure is being increasingly recognized as a complication in patients undergoing liver transplantation for hepatitis C virus (HCV). However, its precise incidence, predisposing risk factors, and impact on outcome after liver transplantation, have not been defined.

METHODS

The development of late-onset renal failure (defined as serum creatinine persistently >2.0 mg/dl, occurring more than 6 months posttransplant) was assessed in 120 consecutive liver transplant recipients who survived at least 6 months after transplantation. Fifty-seven percent (68/120) of the patients had undergone transplantation for liver disease due to HCV. The median follow-up was 5 years.

RESULTS

Late-onset renal failure developed in 28% (33/120)of the patients. Posttransplant alcohol use (P=0.0001), posttransplant diabetes (P=0.0042), and recurrent HCV hepatitis (P=0.019) were significantly associated with late onset renal failure. In multivariate analysis, alcohol use (O.R. 10.7, 95%; CI 2.4-35.9, P=0.001) and diabetes (O.R. 2.1, 95%; CI 1.1-9.9, P=.03) were independently significant predictors of late onset renal failure. When only patients transplanted for HCV were analyzed, posttransplant alcohol use (P=0.004) was the only significant independent predictor of late-onset renal failure. HCV genotype 1b, as compared with other HCV genotypes, was associated with a higher rate of late-onset renal failure in patients with HCV; 70% of the patients with genotype 1b versus 32% of those with 1a and 33% of those with 2b, developed late onset renal failure (P=0.03). At a median follow up of 5 years, mortality in patients with HCV with late-onset renal failure was 52% as compared with 2% in those without renal failure (P=.0001).

CONCLUSION

Late-onset renal failure in patients with HCV portended a grave outcome. Alcohol use was an independent predictor of late-onset renal failure in patients with HCV and represents a potentially modifiable risk factor for late-onset renal failure in these patients.

Cyclosporine and tacrolimus (FK506): a comparison of efficacy and safety profiles

Multicenter clinical trials conducted in the United States and Europe to compare the efficacy and safety of cyclosporine with tacrolimus (FK506) have demonstrated comparable long-term patient survival and graft survival in liver and renal transplant recipients. Importantly, treatment with tacrolimus was associated with reductions in the incidence and severity of acute rejection episodes. However, tacrolimus-based therapy was also associated with increased toxicities in comparison to conventional cyclosporine-based therapy. It is becoming increasingly accepted that earlier trials may have employed high or supratherapeutic doses of tacrolimus and may have been unbalanced with respect to study design. In addition, these pivotal comparative trials were performed with the original formulation of cyclosporine, and not the cyclosporine microemulsion preparation. This critical review of the literature focuses on the United States and European tacrolimus multicenter clinical trials and examines the efficacy and safety of the two primary immunosuppressants, cyclosporine and tacrolimus, obtained in these and other studies. The preliminary findings of ongoing studies comparing the efficacy and safety of the improved formulation, cyclosporine microemulsion, with tacrolimus are also discussed. The overall efficacy of the two agents appears to be similar. The safety profile shows differing toxicities of the two medications. The availability of these two immunosuppressants allows the clinician improved options when choosing an immunosuppressive regimen in 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.

Inhibitory effect of cyclosporin A peptide on rat hepatocytes proliferation induced by mitogens

Treatment of cultured rat hepatocytes with cyclosporin A (0.01-1 microM) for 24, 48, or 72 h in the presence of insulin and epidermal growth factor induced an inhibition on cell proliferation in a time- and concentration-dependent manner, with an IC50 = 0.05 microM CsA corresponding to 48-h treatment. The inhibitory effect of CsA at < or = 0.1 microM doses for 48 h on [3H]thymidine uptake was reversed after withdrawal of the drug and subsequent addition of insulin plus EGF or serum; however, at 1 microM CsA the effect was irreversible and numerous bright small vesicles were observed. The molecular mechanism involved in CsA action in hepatocytes seems to be independent on cAMP and pertussis-toxin sensitive G proteins.

Mycophenolate mofetil decreases rejection in simultaneous pancreas-kidney transplantation when combined with tacrolimus or cyclosporine

BACKGROUND

Historically, the acute rejection rates in simultaneous pancreas-kidney (SPK) recipients have been extremely high (50-80%), with many second and third rejection episodes despite the use of quadruple immunosuppression (antibody induction and cyclosporine [CsA]-azathioprine [AZA]-based maintenance immunosuppression). Although this acute rejection has rarely led to graft loss, it has been a great cause of morbidity and of significantly increased cost. In an attempt to decrease the acute rejection rate and related morbidity in SPK transplant recipients, we compared two "state-of-the-art" immunosuppression regimens in a prospective, randomized, single-center study.

METHODS

Patients who received SPK transplants were randomized to receive either tacrolimus (TAC) and mycophenolate mofetil (MMF, n=18) or CsA (Neoral formulation) and MMF (n=18). All patients received OKT3 induction and prednisone, which was tapered to 5 mg/day by 6 months after transplantation. All rejection episodes were biopsy proven. In addition, metabolic control (HgbA1C, hypertension, serum cholesterol), drug toxicity, and infection also were measured. Data were compared with that of a historical group (n=18) who received conventional CsA (Sandimmune formulation) and AZA-based immunosuppression.

RESULTS

The incidence of biopsy-proven acute rejection was 11% in both the TAC-MMF and CsA-MMF groups with only two patients in each group experiencing a rejection episode. This rejection rate was significantly decreased from that of the CsA-AZA historical group (77%, P<0.01). There were no significant differences in infection rates, including cytomegalovirus, or in metabolic control (HgbA1C, hypertension, and cholesterol levels). All patients remained on their initial immunosuppression regimen for the first 3 months after transplantation. Between 3 and 6 months after transplantation, three patients were switched from TAC to CsA for recurrent migraine headaches, posttransplant diabetes, and chronic cytomegalovirus infection. Two patients in the CsA-MMF group died of nonimmunologic causes (aspiration pneumonia and arrhythmia) between 3 and 6 months after transplantation.

CONCLUSIONS

The data from this study show that MMF treatment significantly decreases the incidence of biopsy-proven acute rejection in SPK transplant recipients compared with AZA-treated historical controls. In addition, we conclude that TAC and CsA (Neoral), when combined with MMF, yield similar, low acute rejection rates with similar graft function and metabolic control.

An update on new immunosuppressive drugs undergoing preclinical and clinical trials: potential applications in organ transplantation

Recent advances in immunobiology and immunopharmacology have led to a better understanding of the actions of immunosuppressive drugs. Over the past 2 years, a number of new agents have been approved for use in solid organ transplant recipients. In addition, new immunosuppressive agents are being tested in preclinical and clinical trials, leading to the promise of an exciting future in organ transplantation. This report reviews the mechanisms of action and the potential future role of these agents in clinical transplantation.

Early graft loss secondary to massive hemorrhagic necrosis following orthotopic liver transplantation. Evidence for cytokine-mediated univisceral Shwartzman reaction

Massive hemorrhagic necrosis (MHN) of the liver following orthotopic liver transplantation (OLT) occurs infrequently during an otherwise uneventful recovery 1 week after OLT. It is characterized by fever and sudden deterioration of allograft function leading to failure in the absence of vascular thrombosis. The etiology is unknown, although it is usually preceded by some degree of allograft rejection. Between 6 and 8 days after OLT, four patients (out of 150) became febrile, hypotensive, and experienced a rapid rise in transaminases within 48 hr. Two patients had evidence of mild rejection; the other two had moderate to severe acute cellular rejection. All patients were ABO identical, crossmatch negative. Bolus steroids were given followed by OKT3 in the two patients with severe rejection. Although sepsis was suspected, antibiotic therapy did not ameliorate the clinical course. Each patient progressed to MHN with severe centrilobular necrosis and variable portal infiltrate. High levels of interferon-gamma and tumor necrosis factor-alpha occurred prior to the rise in transaminases in each MHN patient (155 +/- 39 pg/ml and 414 +/- 201 pg/ml, respectively) compared with levels in OLT patients with severe rejection (14 +/- 4 pg/ml and 26 +/- 5 pg/ml, respectively, P < 0.05). These data support the concept of a cytokine-mediated inflammatory response leading to a univisceral Shwartzman reaction in the transplanted liver. Early recognition of this syndrome and retransplantation are critical for survival.