ORIGINAL ARTICLE. Received April 7, 2009; accepted July 27, 2009.

Transcription

1 LIVER TRANSPLANTATION 15: , 2009 ORIGINAL ARTICLE Thymoglobulin Induction in Liver Transplant Recipients with a Tacrolimus, Mycophenolate Mofetil, and Steroid Immunosuppressive Regimen: A Five-Year Randomized Prospective Study Olivier Boillot, 1 Belhassen Seket, 1 Jérôme Dumortier, 1 Gabriella Pittau, 1 Catherine Boucaud, 1 Yves Bouffard, 1 and Jean-Yves Scoazec 2 1 Liver Transplant Unit and 2 Department of Pathology, Edouard Herriot Hospital, Lyon, France This randomized, comparative study assessed the long-term efficacy and tolerability of thymoglobulin (TMG) induction in 93 liver transplant patients with an initial regimen of tacrolimus (Tac), mycophenolate mofetil (MMF), and steroids. Forty-four patients were randomly allocated to the group, and 49 patients were randomly allocated to the group. In both groups, Tac was given orally at the initial daily dose of mg/kg twice daily, and MMF was given at the initial daily dose of 2 g/day. Steroid withdrawal was planned at 3 months after liver transplantation. The results were evaluated with respect to acute rejection incidence, patient and graft survival, graft function, and medical complications until 5 years or death for all patients. No significant differences were found between groups for the incidence of acute rejection at 5 years (11.4% versus 14.3%), 5-year patient survival (77.3% versus 87.8%), graft function, or postoperative renal function. One patient in the group underwent retransplantation. There was no difference between groups with respect to the incidence of medical complications, excepted for a higher rate of leukopenia in the group, during the 5-year follow-up. In conclusion, the results of this prospective randomized study suggest that the addition of TMG to a triple immunosuppressive regimen (Tac, MMF, and steroids) did not modify the incidence of acute rejection episodes or long-term survival and was responsible for increased leukopenia rates. Liver Transpl 15: , AASLD. Received April 7, 2009; accepted July 27, Since the introduction of calcineurin inhibitors (CNIs) to clinical liver transplantation (LT), patient survival and graft survival have dramatically improved. Nevertheless, side effects of CNIs often negatively affect longterm outcomes. Corticosteroids and CNIs are associated with significant metabolic, renal, and cardiovascular complications. As transplant recipients now have longer survival, the major challenge is optimizing the use of various immunosuppressive agents in order to minimize long-term toxicity and enhance both graft acceptance and patient quality of life. When this study was designed and elaborated, in 1997, tacrolimus (Tac) and mycophenolate mofetil (MMF) had just been introduced into the French market with the aim of ensuring improved control of graft rejection and long-term efficacy in comparison with historical immunosuppressive regimens, including cyclosporine and steroids with or without the use of azathioprine. At that time, US and European randomized, multicenter liver studies 1-3 had demonstrated the superiority of Tac over cyclosporine in terms of the incidence of acute, refractory, and chronic rejection, Abbreviations: ATG, antithymocyte globulin; CC/HJ, choledochocholedochostomy/hepaticojejunostomy; CI, confidence interval; CMV, cytomegalovirus; CNI, calcineurin inhibitors; GFR, glomerular filtration rate; HCC, hepatocellular carcinoma; HCV, hepatitis C virus; KM, Kaplan-Meier; LT, liver transplantation; MELD, Model for End-Stage Liver Disease; MMF, mycophenolate mofetil; POD, postoperative day; RBC, red blood cell; SD, standard deviation; Tac, tacrolimus; TMG, thymoglobulin. Address reprint requests to Olivier Boillot, Liver Transplant Unit, Edouard Herriot Hospital, Place d Arsonval, Lyon, France. Telephone: ; FAX: ; boillot@cismsun.univ-lyon1.fr DOI /lt Published online in Wiley InterScience ( American Association for the Study of Liver Diseases.

2 THYMOGLOBULIN INDUCTION IN LT RECIPIENTS 1427 steroid sparing, decreased need for OKT3, and 3-year graft and patient survival. In the mid 1990s, a new antimetabolite drug, MMF, was shown to significantly decrease the number of acute rejection episodes in kidney transplantation. 4,5 Therefore, its use in LT in association with Tac seemed potentially promising. Polyclonal antithymocyte globulins (ATGs) have been used for the prevention and treatment of acute rejection for over 30 years, mainly in kidney transplantation. In kidney transplantation, ATGs have been shown to increase graft survival in a non-cni regimen, 6 to reverse acute allograft rejection, 7 to decrease the incidence of delayed graft function, 8 and to lower the rate of acute and steroid-resistant rejection episodes in comparison with no induction regimens Nevertheless, in most studies, patient and graft survival were not influenced by induction, and hematological and infectious adverse events were more frequently reported. Thymoglobulin (TMG), a rabbit anti-human thymocyte globulin [Imtix Sangstat (formerly Institut Mérieux), Lyon, France], in comparison with Atgam, a horse ATG (Pharmacia-Upjohn, Kalamazoo, MI), was found to be more effective in reversing and preventing acute rejection episodes in kidney transplantation. 11 In a nonhuman primate model, TMG treatment induced a dose-dependent depletion of T cells through apoptosis in peripheral lymphoid tissues. 12 Induction therapy using ATG in LT is not commonly accepted. At the end of the 1990s, induction was very rarely used. The initial goal of induction was to decrease rejection incidence and, in very ill patients with renal failure, to delay CNI introduction. In the 1990s, Tchervenkov et al. 13 and Schulak et al. 14 pointed out the beneficial effect of ATG use for the prevention of early acute rejection in a cyclosporine-based regimen. In fact, in unpublished data from our group, we observed in the early 1990s that a 10-day TMG induction course in a cyclosporine-azathioprine-steroid regimen was able to significantly reduce the incidence of acute rejection to 30% versus 60% to 70% when no induction was given. Therefore, the rationale of this single-center study over a full 5-year period was to evaluate the interest of an induction therapy with TMG in a new regimen including Tac, MMF, and steroids. PATIENTS AND METHODS Study Design This prospective, monocenter, randomized, open-label study compared the efficacy and safety of a quadruple immunosuppressive therapy including Tac, MMF, steroids, and TMG induction treatment with those of the same regimen without TMG induction over a 5-year period for all surviving recipients. Patient Eligibility Eligible patients were adults undergoing primary orthotopic liver allograft transplantation, including partial organ transplantation. All patients provided informed consent before the initiation of the study. Exclusion criteria included retransplantation, multiorgan transplantation, or living donor transplantation, ABO blood group incompatible grafts, the previous administration (in the last 3 months) of any immunosuppressive drugs, serum creatinine above 180 mol/l, human immunodeficiency virus seropositivity, or a history of malignancy except for hepatocellular carcinoma (HCC) within the Milan criteria. Participation in another clinical trial or treatment with an experimental compound within the previous month and unlikely compliance with the study schedule were additional exclusion criteria. Treatments After randomization according to a randomization table, patients were administrated either TMG ( group) or no induction ( group). In order to not expose the patients to excessive bacterial and/or viral infections, patients were started on TMG intraoperatively at a daily dose of 100 mg for 6 days. In both groups, Tac was given orally from the day of LT at the initial daily starting dose of mg/kg twice daily; the daily dose was then adjusted to reach the following Tac trough level targets: 8 to 12 ng/ml during the first month, 7 to 10 ng/ml during the first year, and 3 to 7 ng/ml thereafter according to patient and graft tolerance. MMF was to be administrated orally according to patient tolerance at the initial daily dose of 2 g and progressively tapered to 1 g/day or less according to efficacy and safety. As for steroids, 500 mg of solumedrol was given intraoperatively, and thereafter, patients received 20 mg per day, which was progressively tapered to 5 mg. Whenever possible, patients were withdrawn from steroids after 3 months post-lt. The treatment of acute rejection included intravenous solumedrol boluses (1000 mg/day for 3 days) or increased doses of Tac. 15 All patients were given cytomegalovirus (CMV) prophylaxis with intravenous ganciclovir (5 mg/kg twice a day according to glomerular filtration rate measurements) for 10 days, and this was followed by the administration of 1 g twice a day of oral ganciclovir for 3 months (6 months in CMV-negative patients receiving a CMV-positive graft). Patient Monitoring In addition to the usual posttransplant follow-up, special attention was paid to repeated laboratory tests (hematological parameters with a complete blood count and biochemical parameters including liver and renal parameters) and the search for infection (with drain samples and blood tests for viral infections, including CMV polymerase chain reaction tests). Hepatitis C virus (HCV) recurrence was determined with serology, the viral load by quantitative polymerase chain reaction, and liver biopsy whenever required. Episodes of acute rejection were verified by the histological examination

3 1428 BOILLOT ET AL. TABLE 1. Patient Demographics (n 44) (n 49) Recipient age (years; mean standard deviation) Recipient weight (kg; mean standard deviation) Sex ratio: male/female (%) 57/43 59/41 Mean MELD score (mean standard deviation) Child-Pugh class: A/B/C (%) 14/32/54 26/41/33 Mean serum creatinine level ( mol/l; mean standard deviation) Estimated GFR (ml/minute; mean standard deviation) Liver diseases [n (%)] Alcoholic cirrhosis 25 (57) 16 (33) Virus-related cirrhosis 10 (23) 14 (29) Primary biliary cirrhosis 1 (2) 3 (6) Primary sclerosing cholangitis 1 (2) 5 (10) Fulminant hepatitis 1 (2) 1 (2) Cryptogenic cirrhosis 1 (2) 2 (4) Miscellaneous 5 (11) 8 (16) Associated HCC [n (%)] 8 (18) 4 (8) Abbreviations: GFR, glomerular filtration rate (Cockroft formula); HCC, hepatocellular carcinoma; MELD, Model for End-Stage Liver Disease; TMG, thymoglobulin. of core biopsy specimens whenever this was indicated by liver function test deterioration. Graft function was evaluated yearly from 1 to 5 years post-lt with a histological graft assessment at 5 years. A histological diagnosis of rejection was performed according to the Banff score 16 ; an evaluation of inflammation and fibrosis was performed according to the METAVIR score. 17 Statistical Analysis Over a 5-year follow-up of all surviving patients, the primary endpoint was the incidence of biopsy-proven acute rejection. Secondary endpoints were 5-year patient and graft survival, liver and kidney function over the 5-year follow-up, and the incidence of medical complications. Acute rejection was suspected on abnormal liver function tests and was defined by histological features according to the Banff classification. 16 Incidence rates between groups were compared with the chi-square test or Fischer s exact test with 95% confidence intervals (CIs) and odds ratios. Quantitative data were expressed as means and standard deviations. For qualitative data (expressed as means and standard deviations), a chi-square test was computed with the 95% CI of the difference between percentages. If conditions to realize a chi-square test were not met, an exact Fisher test was performed with the 95% CI of the difference between percentages. Longitudinal quantitative data were analyzed with a mixed model with treatment, time, and treatment time interactions and subject as a random factor. For acute rejection and 5-year survival, Kaplan-Meier estimates and log-rank testing were performed, and odds ratios with 95% CIs were computed. RESULTS From May 1997 to May 1999, a total of 93 primary LT adult patients were enrolled in this study, with 44 patients randomized to the group and 49 patients randomized to the group. All recipients were followed up for at least 5 years or until death. Patients/Donors Patient demographics, which are summarized in Table 1, were not statistically different between groups. Donor and transplant characteristics are presented in Table 2. All donors were deceased and heart-beating, and no differences between groups were found for age, gender, hypotensive episodes (blood pressure below 80 mm Hg for more than 1 hour), or the use of vasopressive drugs. Among 93 liver grafts, 8 were right split livers, and they were given to 4 patients in each group. Transplant characteristics were not statistically different between groups. With respect to CMV status, 18.1% and 22.9% of CMV-negative recipients in the and in groups, respectively, received a CMV-positive graft. Acute Rejection Incidence Over the 5-year follow-up period, there were no differences between the groups with respect to the incidence of and time to biopsy-proven acute rejection, with 5 patients in the group (11.4%; 95% CI ) and 7 in the group (14.3%; 95% CI ) who experienced 1 episode of acute rejection (Fig. 1). According to the Banff classification, 2 and 1 episodes of rejection were mild, 1 and 4 were moderate, and 2 and 2 were severe in the and groups, respectively. The mean time to rejection was days ( days) after LT for the patients versus days (4-110 days) for the patients. Because of the low rate of acute rejection, this did not reach significance. The 2 severe ACR events occurred on days 123 and 127 in the group and on days 47 and 110 in the

4 THYMOGLOBULIN INDUCTION IN LT RECIPIENTS 1429 TABLE 2. Donor and Transplant Characteristics (n 44) (n 49) Mean donor age (years; mean standard deviation) Sex ratio: male/female (%) 75/25 61/39 Hypotensive episode ( 80 mm Hg) 42.9% 34.7% Donor under vasopressive drugs 50% 46.9% Mean cold ischemia time (minutes) Mean transplant duration (minutes) Mean RBC transfusion (units) Biliary anastomosis (CC/HJ) 41/3 41/8 Abbreviations: CC/HJ, choledochocholedochostomy/hepaticojejunostomy; RBC, red blood cell; TMG, thymoglobulin. Figure 1. Acute rejection occurrence by treatment group. Over the 5-year period, there were no differences between groups with respect to the incidence of and time to biopsyproven acute rejection. Abbreviations: KM, Kaplan-Meier; TMG, thymoglobulin. [Color figure can be viewed in the online issue, which is available at group. The 2 patients in the group had LT for primary biliary cirrhosis and HCV cirrhosis. Depending on the grades and liver function tests, all rejection episodes were treated and reversed with increased doses of Tac (2 mild, 4 moderate, and 1 severe), increased doses of Tac combined with augmentation of the MMF dose (1 mild and 1 moderate), or the administration of steroid boluses (3 severe). Patient and Graft Survival and Causes of Death Seventy-seven (82.8%) of the 93 patients enrolled in the study completed the 5-year follow-up (34/44 in the group and 43/49 in the group). The 5-year patient survival rates were 77.3% and 87.8% in the and groups, respectively, with no statistically significant differences between groups (P 0.18; Fig. 2). One patient in the group underwent retransplantation 1 year after transplantation for HCV recurrence but died soon after from Figure 2. Five-year patient survival by treatment group. The 5-year patient survival rates were not statistically different between groups. Abbreviations: KM, Kaplan-Meier; TMG, thymoglobulin. [Color figure can be viewed in the online issue, which is available at sepsis. There were 10 deaths in the group and 6 in the group. The causes of death were sepsis (n 4), HCC recurrence (n 3), de novo cancer (n 1), cerebral hemorrhage (n 1), and myocardial infarction (n 1) in the group, whereas they were sepsis (n 3), cholangiocarcinoma recurrence (n 1), de novo cancer (n 1), and HCV recurrence (n 1) in the group. Graft Function There was no primary graft nonfunction, whereas 7 early dysfunctions (defined as aminotransferases above 1500 IU/L and a prothrombin rate below 50% on day 7) occurred and spontaneously improved without the need for retransplantation (3 in the group and 4 in the group). Means of hepatic function parameters were calculated for the early postoperative period (ie, from transplantation to postoperative day 90). No statistically significant differences between groups were found for any of these parameters during this period. During the 5-year study follow-up, there were also no significant differences between groups. Nevertheless, a significantly higher number of patients had normal liver func-

5 1430 BOILLOT ET AL. TABLE 3. Serum Creatinine Levels from 1 to 5 Years Creatinine ( mol/l) n Mean SD n Mean SD 1 year years years years years NOTE: Normal creatinine values are Abbreviations: SD, standard deviation; TMG, thymoglobulin. tion tests at 5 years in the group (41/43) versus the group (27/34; P 0.03). All abnormal values concerned elevated gamma glutamyl transferase. Liver biopsy specimens at 5 years were normal or nearly normal (ie, mild nonspecific portal inflammatory infiltrates, steatosis less than 30%, and a fibrosis score less than F2) in 79.5% (31/39) of patients and in 70.6% (24/34) of patients. Abnormalities were massive steatosis associated with dysmetabolic disorder (5 patients and 5 patients), fibrosis associated with HCV recurrence (2 patients), fibrosis associated with alcoholic relapse (2 patients), fibrosis associated with HBV recurrence (1 patient), recurrence of primary sclerosing cholangitis (1 patient), recurrence of nonalcoholic steatohepatitis (1 patient), and moderate steatosis (1 patient). Kidney Function Perioperatively, a total of 19 patients (20.4%) had 1 or more sessions of hemodialysis for temporary kidney function impairment without significant differences between groups (25% in the group versus 16.3% in the group, P 0.3). In univariate analysis, Child status (P 0.008), Model for End-Stage Liver Disease (MELD) score (P ), pretransplant creatinine serum levels (P 0.023), and intraoperative blood transfusion (P 0.023) were factors associated with a post-lt hemodialysis requirement. No statistically significant difference between groups was observed for creatinine changes over the 5-year study follow-up (Table 3). Nevertheless, serum creatinine levels were higher for both groups in patients who had early postoperative hemodialysis, but the differences did not reach statistical significance. No patient required renal dialysis during the 5-year follow-up. Medical Complications During the 5-year follow-up, there were no differences between groups with respect to the rate of bacterial and viral infections, which mainly occurred during the first year after LT. Bacterial infections requiring antibiotic therapy were reported in 22 (50%) and 18 patients (37%) in the and groups, respectively, and CMV infection was reported in 6 (13.6%) and 3 (6.1%) patients in the and groups, respectively. Five (55.5%) of the 9 CMV infection episodes occurred in D /R patients. De novo diabetes, defined as the need for insulin therapy for more than 30 days, occurred in 21% (9/44) of patients and 18% (9/49) of patients (P not significant). De novo arterial blood pressure hypertension, defined as the need for the administration of prolonged antihypertensive medication, occurred in 30% (13/44) of patients and 27% (13/ 49) of patients (P not significant). No posttransplant lymphoproliferative disease or any Kaposi syndrome was reported in the 2 groups. HCV recurrence was diagnosed in 5 of 7 patients in the group and in 8 of 10 patients in the group (P not significant). Three of 12 patients with associated HCC experienced a recurrence of the disease. The 3 patients who had HCC recurrence were in the group, but 2 of them had vascular invasion on explant pathology; moreover, they had more than 5 tumors, with the largest one up to 5 cm (no other patient in either group was found to have vascular invasion). The third patient with HCC recurrence was a 45-year-old woman with Budd- Chiari syndrome, and the 25-mm HCC tumor was poorly differentiated. A total of 9 (9.6%) de novo malignancies (4 oropharyngeal, 2 pulmonary, 2 esophageal, and 1 of unknown origin) were diagnosed during the follow-up period in 3 and 6 patients in the and groups, respectively. The majority of these cancers (7 cases) arose in patients with previous combined pretransplant alcohol and tobacco abuse. White blood cell counts over time during the first postoperative week were significantly lower in the group versus the group (P 0.05), mainly with respect to lymphopenia. Over the 5 years following transplantation, leukopenia, defined as a white blood cell count below 4000/mm 3, was reported in a significantly (P 0.02) higher number of patients in the

6 THYMOGLOBULIN INDUCTION IN LT RECIPIENTS 1431 TABLE 4. Daily Tac Doses and Trough Levels During the First 15 Days After Liver Transplantation Tac Dose (mg/kg) P Tac Trough (ng/ml) P POD Abbreviations: POD, postoperative day; Tac, tacrolimus; TMG, thymoglobulin. group (36/42, 86%) versus the group (30/47, 64%). Immunosuppressive Treatments Table 4 summarizes the mean Tac daily dosages and blood trough levels during the first 15 days following transplantation. The Tac daily dosage and trough levels were significantly lower in the group during the first 9 days after LT versus the group (P 0.05 for both). Information regarding the following period, from 1 year to 5 years, is provided in Table 5. At none of these times were significant differences found between the 2 groups with respect to the Tac dosages and trough levels. A switch from Tac to cyclosporine was reported for 3 patients (1 for a neurological disorder at 4 years post-transplantation and 2 for de novo diabetes, 1 at 2 years and 1 at 5 years post-transplantation) and for 4 patients (all for de novo diabetes, 3 at 5 years and 1 at 4 years). MMF and steroid dosages over the 5-year follow-up period are shown in Table 5. The percentage of patients treated with MMF was 64% in the group and 43% in the group at 1 year and 59% in the group and 53% in the group at 5 years. The main causes of MMF withdrawal were digestive and hematological side effects. Steroids were administered to 28% and 17% of patients at 1 year and 12% and 7% of patients at 5 years in the and groups, respectively (Table 5). The mean time to corticosteroid withdrawal was significantly shorter (P 0.05) for the patients: months versus months for the patients. DISCUSSION In this comparative, prospective, randomized, open-label study, we report that there were no statistically significant differences with respect to efficacy outcomes between patients receiving a standard immunosuppressive regimen with Tac, MMF, and steroids and patients receiving TMG in association with the same regimen over 5 years post-transplantation. During this study period, the incidence of acute rejection was very low whether or not TMG was added to the Tac/MMF regimen, and this emphasized the potency of this dual therapy in LT. Moreover, neither refractory nor chronic rejection was observed during the 5-year follow-up. In this trial, which was designed before the MELD area, kidney function was one of the concerns but not the main one. At that time, the main interest was the initial and long-term liver function under the new and potentially powerful combination of Tac and MMF. In the present series, 5-year patient survival under Tac and MMF dual therapy was 82.8%, and this compares favorably with numerous published data. A 10% difference in patient survival favoring the group (87.8%) was observed in comparison with the group (77.3%), but the difference did not reach significance (P 0.18). Moreover, only 1 patient underwent retransplantation for HCV recurrence. In accordance with our observation, the addition of MMF to Tac was shown to significantly lower the incidence of acute rejection and reduce the need for steroids in comparison with Tac alone in prospective, randomized studies of LT recipients. 18,19 In a study by Jain et al., 19 the use of MMF in addition to Tac was able to reduce the rate of acute rejection from 38.9% (Tac alone) to 28%, even though a high number of patients discontinued MMF because of side effects. The positive

7 1432 BOILLOT ET AL. TABLE 5. Immunosuppression from 1 to 5 Years Tacrolimus Daily Dosage (mg/kg) Trough (ng/ml) Daily Dosage (mg/kg) Trough (ng/ml) n Mean SD n Mean SD n Mean SD n Mean SD 1 year years years years years MMF (g) n Mean SD n Mean SD 1 year 25/39 (64%) /46 (43%) years 20/38 (53%) /44 (41%) years 19/36 (53%) /43 (42%) years 20/35 (57%) /43 (53%) years 20/34 (59%) /43 (53%) Corticosteroids (mg) n Mean SD n Mean SD 1 year 11/39 (28%) /46 (17%) years 9/38 (24%) /44 (11%) years 4/36 (11%) /43 (7%) years 5/35 (14%) /43 (12%) years 4/34 (12%) /43 (7%) Abbreviations: MMF, mycophenolate mofetil; SD, standard deviation; TMG, thymoglobulin. role of MMF in association with Tac seems clear, whereas the addition of azathioprine to a Tac-based regimen was not found to add beneficial effects to Tac alone in a French multicenter, randomized trial. 20 There are few studies comparing TMG and no TMG induction in LT. The majority of studies have stated that induction therapy with TMG is associated with less incidence of acute rejection, acute rejection episodes requiring corticosteroids, and corticoresistant rejection in comparison with no induction immunosuppressive regimens. 13,21-25 Only 1 randomized study from the Berlin group, 26 comparing a quadruple Tac-based induction therapy including azathioprine and TMG to a standard regimen with Tac and steroids, did not found any differences in terms of the number and severity of rejection episodes; moreover, the incidence of CMV infection was higher in the quadruple group. In a randomized study from Eason et al., 22 a steroid-free regimen using rabbit ATG and early Tac monotherapy was able to significantly lower the rates of steroid requirement for acute rejection treatment, posttransplant diabetes, and CMV infection in comparison with the steroid/tac and no-induction group. In the same way, similar features were observed in a large randomized study when daclizumab induction was used instead of TMG. 27 The beneficial effect of TMG induction and delayed CNI introduction was shown to improve posttransplant kidney function in several studies, especially in comparison with no induction therapy and immediate CNI treatment. 23,24,25,28 In a retrospective study of 391 LT patients, 3-day ATG induction therapy with the delayed use of CNIs was associated with a lower rejection rate at 1 year (14.5% versus 31.8%) and better serum creatinine levels and glomerular filtration rates at 1 year in comparison with a group of patients who received a CNI immediately after transplantation. 24 The sparing effect on kidney function was also observed in another retrospective study, with a lower serum creatinine level, a higher estimated glomerular filtration rate, and less dependence on dialysis in patients treated with TMG and delayed CNI initiation in comparison with patients treated with no ATG and early CNI introduction. 25 Therchenkov et al. 23 supported the idea that TMG induction with delayed CNI introduction was much more beneficial to very ill patients with pretransplant renal impairment, improving both postoperative renal function and patient survival in comparison with the same patients who did not receive induction therapy. Regarding the duration of TMG treatment, Soliman et al. 29 pointed out that a 3-day induction

8 THYMOGLOBULIN INDUCTION IN LT RECIPIENTS 1433 therapy compared to a 10-day course was equally efficient for the prevention of acute rejection and was associated with fewer fatal outcomes in infected patients. In this series, 88% and 93% of patients in the and groups, respectively, were off steroids at 5 years post-lt with mean withdrawal intervals of 9.1 and 4.7 months, respectively. Steroid elimination was not associated with onset of rejection. Avoidance of steroids in LT was shown in some randomized trials to be feasible, usually under cover of antibody induction (anti-cd25 monoclonal antibody or rabbit ATG). Moreover, in several trials, it was associated with low rates of acute rejection episodes and with a lower incidence of steroid-resistant rejection, post-lt diabetes, and viral infections. 21,22,27 In this study, after an initial solumedrol bolus followed by the daily administration of 20 to 5 mg, steroid withdrawal was planned after 3 months post-transplant. Some advocate for even earlier steroid withdrawal on the day following transplantation. 27 An early, 14-day steroid withdrawal protocol administered to LT recipients was associated with no difference in survival (88% for the steroid arm versus 85% for the steroid-free arm), rejection rate (35% versus 48%), or recurrent rejection (25% versus 37%) but was associated with fewer side effects, such as a significant reduction in de novo diabetes (58% versus 30%) and a significant reduction in hypercholesterolemia (41% versus 10%) and hypertriglyceridemia (54% versus 32%). 30 A recent meta-analysis of 30 publications, including 19 randomized trials that compared steroidfree immunosuppression with steroid-based immunosuppression in LT recipients, showed no differences in death, graft loss, or infection. Steroid-free recipients demonstrated a trend toward reduced hypertension, statistically significant decreases in cholesterol and CMV infection, decreased diabetes risk, and lower HCV recurrence, but there were higher rejection rates in steroid-free patients not treated with another immunosuppressive agent. 31 In our study, the incidence of medical complications was not different between the 2 groups. De novo diabetes was reported in 21% and 18% of patients in the and groups, respectively. This rather high level could be explained by the presence of corticosteroids in both groups of patients. Initial and longterm kidney function was not influenced by TMG induction therapy, probably because Tac was immediately administrated after LT. A higher rate of infectious complications (bacterial and CMV) was observed in the group; nevertheless, the difference did not reach statistical significance. The presence of cross-reacting antibodies directed against nonlymphoid cells is known to be responsible for the possible leukopenia observed in association with TMG therapy. 32 This was confirmed in our trial, with significantly lower mean values for the white blood cell count in the group during the first 90 days following transplantation and with a significantly higher number of patients reported with leukopenia in the group (86%) versus the group (64%) during the 5 years following transplantation. In conclusion, in the present study designed in the pre-meld area, we failed to prove any beneficial effect on rejection prevention and on patient and graft survival from the use of TMG induction in a Tac/MMF regimen with rapid elimination of steroids. In both arms, the rejection rate was very low with reduced dose and blood trough levels of Tac in comparison with those recommended by the manufacturer. The addition of MMF allows for a lower Tac dosage and, therefore, a lower risk of Tac-related complications. 33 Because of the potency of the Tac/MMF combination, the interest of TMG induction in LT should be redefined in light of recent advances in transplant immunosuppression with special regard for kidney function. ATG induction, which has been associated in kidney transplantation with fewer acute rejection episodes and less delayed graft function in comparison with basiliximab, 34,35 should still be considered in LT recipients when used as a short induction therapy (ie, 3 days) in combination with a delayed CNI introduction and free-steroid regimen. ACKNOWLEDGMENT The authors thank Laurence Saya, M.D. (Altius Pharma CS), for editorial help and Laurence Dubel, M.D., Ph.D. (Astellas Pharma France), for corrections and helpful comments. REFERENCES 1. US Multicenter FK506 Liver Study Group. 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