The role of Thymoglobulin induction in kidney transplantation: an update

The rabbit antithymocyte globulin Thymoglobulin first became available over 25 yr ago and is the most widely used lymphocyte‐depleting preparation in solid organ transplantation. Thymoglobulin targets a wide range of T‐cell surface antigens as well as natural killer‐cell antigens, B‐cell antigens, plasma cell antigens, adhesion molecules and chemokine receptors, resulting in profound, long‐lasting T‐cell depletion. Randomized studies have established the anti‐rejection efficacy of Thymoglobulin in kidney transplantation. Experimental and clinical data suggest that Thymoglobulin administration may ameliorate ischemia reperfusion injury, thus reducing the incidence of delayed graft function (DGF). Studies have demonstrated the benefit of using Thymoglobulin to facilitate immunosuppression minimization, both for corticosteroid and calcineurin inhibitor (CNI) withdrawal or avoidance, with potential improvement in cardiovascular and renal outcomes. The optimal cumulative dose for Thymoglobulin induction is 6–7.5 mg/kg, with vigilant short‐ and long‐term monitoring of hematological status. Induction with Thymoglobulin is now indicated in immunologically high‐risk patients, in those at increased risk of DGF and to maintain efficacy in low‐risk transplant recipients receiving steroid or CNI minimization or avoidance regimens. We suggest that in future trials Thymoglobulin be tested with costimulation signal blockers and other immunosuppressants with the objective of establishing operational tolerance.     

Thymoglobulin induction in heart transplantation: patient selection and implications for maintenance immunosuppression

Clinical data relating to rabbit antithymocyte globulin (rATG) induction in heart transplantation are far less extensive than for other immunosuppressants, or indeed for rATG in other indications. This was highlighted by the low grade of evidence and the lack of detailed recommendations for prescribing rATG in the International Society for Heart and Lung Transplantation (ISHLT) guidelines. The heart transplant population includes an increasing frequency of patients on mechanical circulatory support (MCS), often with ongoing infection and/or presensitization, who are at high immunological risk but also vulnerable to infectious complications. The number of patients with renal impairment is also growing due to lengthening waiting times, intensifying the need for strategies that minimize calcineurin inhibitor (CNI) toxicity. Additionally, the importance of donor‐specific antibodies (DSA) in predicting graft failure is influencing immunosuppressive regimens. In light of these developments, and in view of the lack of evidence‐based prescribing criteria, experts from Germany, Austria, and Switzerland convened to identify indications for rATG induction in heart transplantation and to develop an algorithm for its use based on patient characteristics.     

Basiliximab induction therapy for live donor kidney transplantation: a long-term follow-up of prospective randomized controlled study

Background/Aims  The effect of basiliximab induction therapy on long-term patient and graft survival is not yet clear. We aimed to evaluate if there is any advantage of routine basiliximab induction on the long-term outcome of living related donor kidney transplantation. Methods  One hundred adult recipients with their first kidney allograft were randomized into two treatment groups, one group received basiliximab and the second served as a control. All patients received a maintenance triple immunosuppressive therapy (steroids, cyclosporine (CsA) micro-emulsion and azathioprinep) and were followed up thoroughly for 7 years. Results  Basiliximab significantly reduced the proportion of patients who experienced acute rejection in the first year (18/50) when compared to the control group (31/50), and in 7 years (28/50) when compared to (37/50) in controls. The cumulative steroid dose used throughout the whole study period was significantly lower in the basiliximab group. The overall incidence of post-transplant complications was comparable among the two treatment groups. There was no significant difference in patient or graft survival; 7 years patient and graft survival were 92, 76% for basiliximab and 92, 80% for the control group, respectively. Conclusion  Routine basiliximab induction significantly reduced the incidence of acute rejection without any noticeble beneficial effect on the long-term renal transplantation outcome.     

Infection and rejection risk after cardiac transplantation with induction vs. no induction: a multi‐institutional study

Data from Cardiac Transplant Research Database (CTRD) were analyzed from 1999 to 2006 to examine the effects of different induction strategies at the time of cardiac transplantation. A total of 2090 primary heart transplants were categorized by induction with interleukin‐2 receptor blocker (IL‐2RB), antithymocyte globulin (ATG), or no induction (NI). Probabilities for rejection and infection were estimated with parametric time‐related models. Using these models, hazard was calculated for two theoretical patient profiles, one at lower risk for rejection and higher risk of infection (Profile 1) and higher risk for rejection and lower risk of infection (Profile 2). Of the 2090 transplants, 49.8% (1095) did not receive induction, 27.3% (599) received IL‐2RB, and 18.0% (396) received ATG. Profile 1 patients had lower hazard for rejection with IL‐2RB compared to ATG and NI (p < 0.01), but at the cost of increased risk of infection (5.0 vs. 1.8 vs. 1.6, respectively, at four wk, p < 0.01). Profile 2 patients experienced a fivefold decreased hazard for rejection when treated with IL‐2RB compared with ATG and NI (p < 0.01). In patients at high risk of infection, IL‐2RB reduced risk of rejection but at the expense of increased hazard for infection.     

Daclizumab induction/tacrolimus sparing: a randomized prospective trial in renal transplantation

Abstract: Tacrolimus inhibits lymphocyte responses by blocking calcium-dependent signalling pathways important in IL-2 generation. Daclizumab, a humanized monoclonal antibody, binds with high affinity to the Tac subunit of the IL-2 receptor complex. We reasoned therefore that the absence of IL-2R should permit lower doses of tacrolimus and thereby less toxicity. Twenty-eight patients were randomized and followed for 6 months: Group 1, high dose (HD) tacrolimus (trough 12–17 ng/mL; n  = 13); Group 2, low dose (LD) tacrolimus (trough 5–10 ng/mL; n  = 15). All patients received daclizumab induction (2 mg/kg) on days 0 and 14, mycophenolate mofetil (2 g/d except for one patient who received 1 g) and rapid prednisone taper. Serious infections were minimal in both groups. Hospitalizations, for various reasons, were HD ( n  = 12) and LD ( n  = 6). All patients and grafts survived for the 6-month study period. There was one rejection episode in a non-compliant patient at 101 d. LD tacrolimus appears equally effective as HD tacrolimus in preventing rejection episodes and may be associated with fewer adverse events.     

Successful management of hemolysis in ABO-nonidentical orthotopic liver transplantation by steroid therapy: a case report

Hemolysis due to donorderived B lymphocytes has been reported in patients who have undergone ABO-nonidentical orthotopic liver transplantation (OLT). Yet, until now, little was known about the management of this transplantation-induced hemolysis. In this report we describe our experience with hemolysis in a patient after OLT. In addition, based on theoretical assumption, we hypothesize that corticosteroids can be helpful in the management of ABO-nonidentical OLT-induced hemolysis.     

A prospective,double-blind,randomized study of high-versus low-dose OKT3 induction immunosuppression in cadaveric renal transplantation

We undertook a prospective, double-blind study of high-(5-mg) versus low-(2-mg) dose OKT3 for induction immunosuppression (12 days) in cadaveric renal allograft transplantation. Maintenance immunosuppression was identical in both groups and consisted of azathioprine and prednisone initially, with cyclosporine beginning on the 5th postoperative day. Twenty-six patients were randomized. The groups were similar in terms of age, kidney ischemia time, peak PRA, and latest PRA. There were more diabetics and women in the high-dose group. Patient survival at 12 months was 100% in both groups. Graft survival at 12 months was 92% and 100% in the high- and low-dose groups, respectively. Infections were mostly minior and equal in frequency in the two groups. All patients receiving high- or low-dose OKT3 had manifestations of the cytokine release syndrome; these were delayed in onset in the low-dose group. Eleven patients (85%) in each group produced anti-OKT3 andtibodies. Lymphocyte depletion after 1 day was major (>98%) and identical in both groups. CD3 antigens were removed more slowly in the low-dose group but eventually at equal rates in both groups. Cost was significantly lower in the low-dose group. We conclude that while both doses of OKT3 were effective and safe for induction immunosuppression, it may be prudent to use a lower dose of OKT3 for induction immunosuppression because of its potential to reduce cytokine-mediated effects and to avoid the complications of overimmunosuppression and because of the lower costs associated with it.     

Preliminary analysis of early outcomes of a prospective, randomized trial of complete steroid avoidance in liver transplantation

Steroids are a mainstay in liver transplantation for induction and maintenance immunosuppression but are associated with significant adverse effects. While prior studies have successfully limited the use of steroids, whether complete steroid avoidance will improve outcomes remains unclear. To further evaluate the need for steroids, consenting patients who underwent liver transplantation between June 2002 and May 2004 were entered into a prospective, randomized trial to receive either standard therapy (tacrolimus, mycophenolate mofetil, steroid induction/maintenance) or complete steroid avoidance (standard therapy without steroid induction/maintenance). Clinically suspected rejection was confirmed by biopsy and treated with pulse steroid therapy. Outcomes were compared on an intention to treat basis. Of the 72 patients enrolled, 36 (50%) were randomized to the steroid avoidance group with a mean follow up of 412 +/- 41 days. Donor and recipient characteristics were similar between groups. The steroid avoidance group was more likely to have significant infections (52% vs 28%, P = .03). There was a trend toward an increased rate of acute rejection (25% vs 14%, P = .23). Twelve of 36 recipients (33%) enrolled in the steroid avoidance group later received steroids. The incidence of recurrent hepatitis C was similar between groups. The 1-year patient (90% vs 83%, P = .44) and graft survivals (90% vs 81%, P = .27) were similar between groups. These data suggest complete steroid avoidance in liver transplantation results in acceptable patient and graft survival. However, the potential long-term benefits of steroid avoidance, including a decrease in severity of recurrent hepatitis C, remain under investigation.     

Reduced dose Thymoglobulin,tacrolimus, and mofetil mycophenolate results in excellent solitary pancreas transplantation outcomes

BACKGROUND: Graft survival following solitary pancreas transplantation has traditionally lagged behind that of simultaneous pancreas-kidney transplants. Thymoglobulin (TMG), a polyclonal rabbit-derived antilymphocyte antibody was originally introduced as treatment for acute rejection of renal allografts. However, data regarding the efficacy of TMG induction in solitary pancreas transplants is lacking. We present the 1-yr graft survival and acute rejection rate of 22 solitary pancreas transplants performed at the McGill University Health Centre using reduced dose TMG induction with lower dose tacrolimus and mophetil mycophenolate. PATIENTS AND METHODS: Eighteen pancreas after kidney and four pancreas transplants alone were performed between January 1998 and October 2000 at McGill University. Induction therapy with TMG at a starting dose of 1.5 mg/kg/d was started 12 h post-operatively. The daily dose of TMG was held if the total leukocyte count was <2,500/mm3 or if the lymphocyte count was <100/mm3. Maintenance therapy was initiated with steroids (tapered to 20 mg prednisone orally once a day) tacrolimus (2 mg twice a day), and mofetil mycophenolate (1 g daily). RESULTS: Patients received three to seven doses of TMG over the first seven post-operative days at a dose of 0.85 +/- 0.27 mg/kg/d (mean +/- SD). The mean follow-up was 1.28 +/- 0.14 yr. The 1-yr patient and graft survival was 100% (22 of 22) and 96% (21 of 22), respectively. The 1 yr acute rejection rate was 27.3% (six of 22). Five of the six rejections responded to steroid boluses. One was refractory to steroids and TMG resulting in graft loss. Presumed rejections were diagnosed on the basis of decreasing urine amylase and/or hyperglycemia. DISCUSSION: Monitoring the total leukocyte and lymphocyte count resulted in a 43% reduction in the amount of TMG used compared with the recommended dosing. Despite the reduced amounts, patient and graft survival were excellent with acute rejection rates comparing favorably to other published series.     

Acute rhabdomyolysis after cardiac transplantation: a diagnostic conundrum

A 13-year-old girl presented with right ventricular failure secondary to Ebstein's malformation (downward displacement of the tricuspid valve leaflets with adherence to the right ventricular muscle and redundancy or dysplasia of the tricuspid valve leaflets). She subsequently required a heart transplant but developed rhabdomyolysis early in the postoperative period and required ventilatory support for more than 3 weeks. A variety of causes were considered, but her condition improved only when cyclosporin was eliminated from the immunosuppression regimen. We believe it is likely that the rhabdomyolysis has been caused by cyclosporin. If so, this has occurred both earlier in the clinical course and at lower serum concentrations than previously described.     

Low-dose OKT3 induction therapy following renal transplantation: a controlled study

In a prospective clinical study we tested the immunosuppressiveproperties and toxicity of low-dose OKT3 induction therapy inrenal transplant recipients. 50 consecutive renal transplantrecipients were alternat ingly assigned to low-dose OKT3 inductionor prednisolone/cyclosporin. Low-dose OKT3 induction treatmentconsisted of 0.5 mg OKT3 twice daily for 10 days, initiallycombined with azathioprine and prednisolone maintenance immunosuppressionthat was converted to prednisolone/cyclosporin at the end ofthe course. During a 15–29-month follow-up period, low-doseOKT3 induction therapy was found to reduce significantly theincidence of acute rejections, as com-pared to the usual prednisolone/cyclosporinmainten ance immunosuppression (21 versus 52%, P=0.02). Therealso was a tendency towards an improved graft function afterlow-dose OKT3, although no signific ance was reached. Furthermore,compared to a histor ical control group of renal transplantpatients in whom acute rejection was treated with 5 mg OKT3daily, low-dose OKT3 appeared to cause fewer side-effects. Weconclude that low-dose OKT3 induction therapy is superior toprednisolone/cyclosporin in preventing acute rejection afterrenal transplantation and that it is better tolerated than conventionalOKT3 treatment.     

Repeated dose administration of desmopressin acetate in uncomplicated cardiac surgery: A prospective, blinded, randomized study

The effects of single or repeated doses of desmopressin on blood loss were examined in uncomplicated cardiac surgery, while assessing the potential for thrombogenic side effects. Seventy patients undergoing elective coronary artery bypass grafting (CABG) were studied. Patients were randomized into three blinded groups: Group I received DDAVP (0.3 micrograms/kg), IV, after cardiopulmonary bypass (CPB) and 12 hours later in the Intensive Care Unit (ICU); Group II, DDAVP (0.3 micrograms/kg), IV, after termination of CPB and saline (placebo) 12 hours later in the ICU; Group III, saline (placebo) IV after CPB and 12 hours later in the ICU. Blood loss and bleeding time decreased for Group I at 24 hours (P < 0.04) when compared to Group III; however, blood product replacement, as well as intraoperative and total blood loss at 36 hours, were not different among treatment and control groups. There were four myocardial infarctions recorded in Group I, two in Group II, and one in Group III. These differences were not found to be statistically significant. It is concluded that in routine CABG the prophylactic use of single or repeat dose DDAVP does not effectively decrease blood loss or blood product replacement.     

Impact of a phosphorylcholine-coated cardiac bypass circuit on blood loss and platelet function: a prospective, randomized study

Platelet dysfunction due to cardiopulmonary bypass (CPB) surgery increases the risk of bleeding. This study analyzed the effect of a phosphorylcholine (PC)-coated CPB circuit on blood loss, transfusion needs, and platelet function. We performed a prospective, randomized study at Strasbourg University Hospital, which included 40 adults undergoing coronary artery bypass graft surgery (CABG) (n = 20) or mitral valve repair (n = 20) using CPB. Patients were randomized either to PC-coated CPB or uncoated CPB (10 CABG patients and 10 mitral valve repair patients in each group). Blood loss and transfusion needs were evaluated intra- and postoperatively. Markers of platelet activation and thrombin generation were measured at anesthesia induction, at the beginning and end of CPB, on skin closure, and on days 0, 1, and 5. Comparisons were made by Student's t test or covariance analysis (significance threshold p < or = .05). Blood loss was significantly lower in the PC group during the first 6 postoperative hours (171 +/- 102 vs. 285 +/- 193 mL, p = .024), at the threshold of significance from 6-24 hours (p = .052), and similar in both groups after 24 hours. During CPB, platelet count decreased by 48% in both groups. There was no difference in markers of platelet activation, thrombin generation, or transfusion needs between the two groups. Norepinephrine use was more frequent in the control group (63% vs. 33%) but not significantly. PC-coating of the CPB surface reduced early postoperative bleeding, especially in CABG patients, but had no significant effect on platelet function because of large interindividual variations that prevented the establishment of a causal relationship.     

Primary preventive cardioverter‐defibrillator implantation (Pro‐ICD) in patients awaiting heart transplantation. A prospective,randomized, controlled 12‐year follow‐up study

The aim of this study was to evaluate whether short‐term primary preventive cardioverter‐defibrillator (ICD) implantation as bridge to heart transplantation (HTX) provides any survival benefit. Thirty‐three patients awaiting HTX were randomized to either conventional therapy (control group) or primary preventive ICD implantation (ICD group). Fourteen patients had ischemic cardiomyopathy (ICM) and 19 patients had dilated cardiomyopathy (DCM). Sixteen patients were randomized to the ICD group and 17 patients were randomized to the control group. Twenty patients (61%) were transplanted after a waiting time of 10 ± 9 months. The remaining 13 patients (39%) were not transplanted because of clinical improvement (n = 5), cerebral hemorrhage (n = 3), or death (n = 5). On the waiting list, 3 ICD patients with DCM developed slow VTs without ICD intervention, two patients with ICM (6%) had fast VT terminated by the ICD, and no arrhythmic death was observed. After 11.9 years (median), 13 of 20 HTX patients (65%) and 5 of 13 non‐HTX patients (38%) were alive. Survivors had a higher LVEF (22 ± 6 vs. 17 ± 4%, P = 0.0092) and a better exercise capacity (75 ± 29 vs. 57 ± 24 Watt, P = 0.0566) at baseline as compared to nonsurvivors. This study may not support the general use of primary preventive ICDs as a short‐term bridge to heart transplantation.     

Incidence,risk factors,and outcomes of stroke post‐transplantation in patients receiving a steroid sparing immunosuppression protocol

Corticosteroid use after transplantation is associated with an increased incidence of cardiovascular events and death. Cerebrovascular disease is a common cause of morbidity and mortality post‐renal transplantation; however, a dedicated analysis of cerebrovascular disease in recipients of a steroid sparing protocol has not been reported. The aim of this study was to examine the incidence, risk factors, and outcomes of CVA in transplant recipients receiving a steroid sparing protocol. We retrospectively analyzed 1237 patients who received a kidney alone or a simultaneous pancreas and kidney (SPK) transplant. Fifty‐six of 1237 (4.53%) patients had a CVA post‐transplant. All‐cause mortality was significantly higher in the CVA group compared with the non‐CVA group, OR: 3.4 (1.7–7.0), p < 0.001. Factors found to be associated with increased risk of CVA by multivariate analysis were older age, HR: 1.07 (1.04–1.09), p < 0.001; diabetes at the time of transplantation, HR: 2.83 (1.42–5.64), p = 0.003; corticosteroid use pre‐transplant, HR: 3.27 (1.29–8.27), p = 0.013 and recipients of a SPK, HR: 4.03 (1.85–8.79), p < 0.001. This study has identified subgroups of patients who are at increased risk of CVA post‐transplant in patients otherwise receiving a steroid sparing immunosuppression protocol.     

Obesity following kidney transplantation and steroid avoidance immunosuppression

Abstract:  Obesity is an important co-morbidity within end-stage renal disease (ESRD) and renal transplant populations. Previous studies have suggested that chronic corticosteroids result in increased body weight post-transplant. With the recent adoption of steroid-sparing immunosuppressive strategies, we evaluated the effect of these strategies on body mass index (BMI) after renal transplantation. We examined 95 renal transplant recipients enrolled in National Institutes of Health clinical transplant trials over the past three yr who received either lymphocyte depletion-based steroid sparing or traditional immunosuppressive therapy that included steroids for maintenance immunosuppression. Recipients were overweight prior to transplant and no significant differences existed in pre-transplant BMI among treatment groups. Regardless of therapy, BMI increased post-transplant in all recipients. The BMI increase consisted of an average weight gain of 5.01 ± 7.12 kg (mean, SD) post-transplant. Additionally, in a number of recipients placed on maintenance steroids, subsequent withdrawal at a mean of 100 d post-transplant had no impact on weight gain. Thus, body weight and BMI increase following kidney transplantation, even in the absence of steroids. Thus, patients gain weight after renal transplantation regardless of the treatment strategy. Steroid avoidance alone does not reduce risk factors associated with obesity in our patient population.     

Continuous retrograde warm blood reperfusion reduces cardiac troponin I release after heart transplantation: a prospective randomized study

Abstract During heart surgery, cardiac troponin I (cTn‐I) measurement provides a tool to evaluate different cardioprotective techniques. To investigate myocardial protection during heart transplantation (HTx), cTn‐I and creatine kinase (CK)‐MB release was measured in 42 patients randomized to receving either continuous retrograde warm blood reperfusion or no reperfusion after cold cardioplegia. A significant linear correlation was found between donor heart ischemic time and peaks and the area under the curve of cTn‐I and CK‐MB release. In patients with an ischemic time longer than 90 min, cTn‐I release was significantly lower in those receiving continuous retrograde warm cardioplegia than in controls. No significant difference was observed for CK‐MB, tCK, and myoglobin. Our data suggest that the measurement of postoperative cTn‐I release may provide a method to evaluate ischemic cardiac damage after HTx. When the ischemic time is longer than 90 min, warm retrograde blood cardioplegia provides better myocardial protection than no reperfusion.     

Simultaneous corticosteroid avoidance and calcineurin inhibitor minimization in renal transplantation

Steroids and calcineurin inhibitors (CNI) have been mainstays of immunosuppression but both have numerous side effects that are associated with substantial morbidity and mortality. This study was carried out to determine if steroids can be eliminated with early discontinuation of cyclosporine A (CsA) and later discontinuation of mycophenolate mofetil (MMF). Ninety-six patients with kidney transplants were entered into four subgroups of two pilot studies. All patients received Thymoglobulin induction, rapamycin (RAPA), and the immunonutrients arginine and an oil containing omega-3 fatty acids. Mycophenolate mofetil was started in standard doses and discontinued by 2 years. CsA was given in reduced doses for either 4, 6, or 12 months. Follow-up was 12-36 months. Thirteen first rejection episodes occurred during the first year (14%). Combining all patients, 86% were rejection-free at 1 year, 80% at 2 years and 79% at 3 years. No kidney has been lost to acute rejection. Ninety percent of the 84 patients at risk at the end of the study were steroid-free and 87% were off CNI. Fifty-seven percent of 54 patients with a functioning kidney at 3 years were receiving monotherapy with RAPA. We conclude that this therapeutic strategy is worthy of a prospective multi-center clinical trial.