Thymoglobulin Research Articles

Acute Graft versus Host Disease in Beta Thalassemia Patients Following Allogeneic Haematopoietic Stem Cell Transplantation.

To analyse the frequency, risk factors, and clinical symptoms of acute graft-versus-host disease (aGvHD) in patients with beta-thalassemia major after allogeneic haematopoietic stem cell transplantation (HSCT). Descriptive study. Place and Duration of the Study: Department of Clinical Haematology, Armed Forces Bone Marrow Transplant Centre, Rawalpindi, Pakistan, from January 2017 to December 2021. Data were obtained from patients diagnosed with bone and tissue malignancies (BTM) who had undergone haematopoietic stem cell transplantation (HSCT) and experienced aGVHD. Patients who experienced initial graft failure and individuals who underwent subsequent bone marrow transplantation were excluded. Total of 117 patients diagnosed with BTM underwent fully matched HSCT, including 76 (65%) males, and 41 (35%) females. The median age of the patients undergoing transplantation was 7.34±7.32 years and the donors' median age was 7.6±9.85 years. Among the donors, 53 (45.3%) were males and 64 (54.7%) were females. Gender disparity was observed in 46 (39.3%) instances as a female donor matched with a male recipient. A total of 106 individuals underwent bone marrow harvest (BMH); with 5 (4.3%) patients receiving peripheral blood stem cells (PBSC) and 6 (5.2%) patients receiving both BMH and PBSC. Acute GvHD was observed in 50 (42.7%) patients, including 30 (60%) males and 20 (40%) females. Grade I GvHD occurred in 32 (27.3%) individuals, Grade II GvHD in 16 (13.7%) patients, and Grade III GvHD in one (0.8%) patient. It had no statistically significant association with recipient/donor age, gender disparity, the source of the graft source, the dose of stem cells, or the presence of thymoglobulin (TG). Acute GvHD was observed in high frequency in Beta-thalassemia patients receiving morrow harvesting proportional to their gender distribution. Associated factors were GvHD prophylaxis measure, mucositis and, CMV reactivation. Beta thalassemia major patients, Acute graft versus host disease, Allogeneic haematopoietic stem cell.

Long-term survival with mixed chimerism in patients with AML and MDS transplanted after conditioning with targeted busulfan, fludarabine, and thymoglobulin.

We evaluated long-term outcome in 40 patients with MDS or AML, transplanted from related or unrelated donors following conditioning with targeted busulfan (Bu, over 4 days), fludarabine (Flu, 120 [n = 23] or 250 [n = 17] mg/m2) and thymoglobulin (THY). Compared to 95 patients conditioned with Bu/Cyclophosphamide (Cy) without THY, BuFluTHY-conditioned patients had lower rates of chronic graft-vs.-host disease (GVHD). Adjusted hazard ratios (HR) for BuFlu(120)THY and BuFlu(250)THY-conditioned patients were 1.60 (95% confidence interval (CI) 0.66-3.86) and 1.87 (0.68-5.11), respectively, for relapse; 0.77 (0.30-1.99) and 1.32 (0.54-3.23) for non-relapse mortality; 0.81 (0.42-1.57) and 1.38 (0.72-2.57) for overall mortality; and 0.78 (0.30-2.05) and 1.62 (0.63-4.41) for relapse or death (failure for relapse-free survival). At one year, 45% of BuFlu(120 or 250)THY-conditioned patients had mixed CD3+ chimerism compared to 0% with BuCy (p < 0.0001). None of 7 patients with long-term mixed chimerism had chronic GVHD; two relapsed, five remained stable mixed chimeras. THY is effective in reducing chronic GVHD, and long-term mixed T-cell chimerism can be compatible with relapse-free survival. However, Thy may also be associated with an increased risk of relapse and, dose-dependent, with non-relapse mortality.

Posttransplant Diabetes Mellitus and Immunosuppression Selection in Older and Obese Kidney Recipients

Rationale & ObjectivePosttransplant diabetes mellitus (DM) after kidney transplantation increases morbidity and mortality, particularly in older and obese recipients. We aimed to examine the impact of immunosuppression selection on the risk of posttransplant DM among both older and obese kidney transplant recipients.Study DesignRetrospective database study.Setting & ParticipantsKidney-only transplant recipients aged ≥18 years from 2005 to 2016 in the United States from US Renal Data System records, which integrate Organ Procurement and Transplantation Network/United Network for Organ Sharing records with Medicare billing claims.ExposuresVarious immunosuppression regimens in the first 3 months after transplant.OutcomesDevelopment of DM >3 months-to-1 year posttransplant.Analytical ApproachWe used multivariable Cox regression to compare the incidence of posttransplant DM by immunosuppression regimen with the reference regimen of thymoglobulin (TMG) or alemtuzumab (ALEM) with tacrolimus + mycophenolic acid + prednisone using inverse propensity weighting.Results12.7% of kidney transplant recipients developed posttransplant DM with higher incidences in older (≥55 years vs <55 years: 16.7% vs 10.1%) and obese (body mass index [BMI] ≥ 30 kg/m2 vs BMI < 30 kg/m2: 17.1% vs 10.9%) patients. The incidence of posttransplant DM was lower with steroid avoidance [TMG/ALEM + no prednisone (8.4%) and IL2rAb + no prednisone (9.7%)] than TMG/ALEM with triple therapy (13.1%). After adjustment for donor and recipient characteristics, TMG/ALEM with steroid avoidance was beneficial for all groups [age < 55 years: adjusted HR (aHR), 0.63 (95% confidence interval [CI], 0.54-0.72); age ≥ 55 years: aHR, 0.69 (95% CI, 0.60-0.79); BMI < 30 kg/m2: aHR, 0.69 (95% CI, 0.60-0.78); BMI ≥ 30 kg/m2: aHR, 0.67 (95% CI, 0.57-0.79)]. However, IL2rAb with steroid avoidance was beneficial only for older patients (aHR, 0.76; 95% CI, 0.58-0.99) and for those with BMI < 30 kg/m2 (aHR, 0.63; 95% CI, 0.46-0.87).LimitationsRetrospective study and lacked data on immunosuppression levels.ConclusionsThe beneficial impact of steroid avoidance using tacrolimus on posttransplant DM appears to differ by patient age and induction regimen.

POS-744 CLINICAL CORRELATES AND OUTCOMES OF DUAL BASILIXIMAB AND THYMOGLOBULIN INDUCTION IN KIDNEY TRANSPLANT RECIPIENTS: A NATIONAL STUDY

The unplanned use of dual induction therapy with interleukin-2 receptor blocking antibodies (IL2rAb) and thymoglobulin (TMG) may portend adverse clinical outcomes compared to either therapy alone. We used national transplant registry data to study clinical correlates and outcomes of single versus dual induction therapy in adult kidney-only transplant recipients in the United States (2005-2018). The risk of death and graft loss at 1 and 5 years according to induction therapy type was assessed using multivariate Cox regression analysis (LCLaHRUCL, adjusted hazard ratio with 95% upper and lower confidence limits). Of the 157,351 adult kidney-only transplant recipients included in the study, 67% were treated with TMG alone, 29% were treated with IL2rAb alone, and 5% were treated with both IL2rAb and TMG. Compared with IL2rAb alone induction, the strongest correlates of IL2rAb and TMG induction included Black race, calculated panel reactive antibody (cPRA) ≥80%, prednisone-sparing maintenance immunosuppression, more recent transplant eras, longer cold ischemia time, and delayed graft function. Compared with induction with TMG alone, dual induction therapy was associated with an increased 5-year risk of death (aHR 1.071.151.23; P<0.0001), death-censored graft failure (aHR 1.051.131.22; P<0.05), and all-cause graft failure (aHR 1.061.121.18; P<0.0001). Approximately 15% of kidney transplant patients who received IL2rAb induction also received TMG induction and these recipients had an increased risk of death and graft loss compared with those who received TMG alone. Further research is needed to develop risk prediction tools to guide a safe and optimal induction protocol for kidney transplant recipients.

Impact of Immunosuppressive Strategies on Post–Kidney Transplantation Thrombocytopenia

BackgroundThrombocytopenia after kidney transplantation is a common complication, partly induced by immunosuppressive therapies. Peritransplant thrombocytopenia may cause serious hemorrhages. We assessed the incidence of early posttransplantation thrombocytopenia (defined as a platelet count of <150,000 mm3 or <150 G/L) in de novo kidney transplant recipients (KTRs) across 4 immunosuppressive regimens. MethodsThis was a single-center observational study that included all consecutive KTRs who received either Thymoglobulin (THY) or Grafalon (GRA) and maintenance therapy of either mycophenolate-mofetil (MMF) or everolimus (EVR), associated with tacrolimus/corticosteroids. ResultsBetween July 27, 2016, and September 7, 2018, 237 KTRs were included; 64.6% experienced thrombocytopenia within the first week. Thrombocytopenia was significantly more frequent (P = .004) among GRA-treated patients (73.4%) compared to THY-treated patients (61.3%). These patients also had lower nadir platelet count (120 ± 52 vs 142 ± 48 G/L; P = .002) and lower platelet count at discharge (227 ± 94 vs 243 ± 92 G/L; P = .25). More of the GRA-EVR group had thrombocytopenia (81.0% vs 61.4% in THY-MMF, 60.9% in THY-EVR, and 69.8% in GRA-MMF; P = .081) and a worse nadir platelet count (109 ± 41 in GRA-EVR vs 141 ± 47G/L in THY-MMF, 145 ± 52 G/L in THY-EVR, and 125 ± 56 G/L in GRA-MMF; P = .011) but GRA was the only risk factor for thrombocytopenia in multivariate analyses (P = .002). Rates of hemorrhage, red blood cell transfusions, reoperations needed within the first week, delayed graft function, acute rejection, graft loss, and death did not differ between the groups after a mean follow-up of 25 ± 8 months. ConclusionsGRA associated with EVR led to more frequent and severe thrombocytopenia, although we found no significant clinical consequences.

Thymoglobulin vs. ATG-Fresenius as Induction Therapy in Kidney Transplantation: A Bayesian Network Meta-Analysis of Randomized Controlled Trials.

Background: Thymoglobulin (THG) and antithymocyte globulin-Fresenius (ATG-F) have not been compared directly as induction therapies in kidney transplantation.Materials and Methods: We performed a Bayesian network meta-analysis to compare THG with ATG-F by pooling direct and indirect evidence. Surface under the cumulative ranking curve (SUCRA) values were used to compare the superiority of one method over the other.Results: A total of 27 randomized controlled trials (RCT) were eligible for the network meta-analysis. Efficacy endpoints, as well as safety indicators, were statistically comparable. For efficacy endpoints, THG seemed inferior to ATG-F in preventing delayed graft function [odds ratio (OR): 1.27; SUCRA: 78% vs. 58%], patient deaths (OR: 2.78; SUCRA: 83% vs. 34%), and graft loss (OR: 1.40; SUCRA: 83% vs. 59%), but superior to ATG-F in biopsy-proven acute rejection (BPAR; OR: 0.59; SUCRA: 78% vs. 39%) and steroid-resistant BPAR prevention (OR: 0.61; SUCRA: 76% vs. 49%) within the first year. For safety endpoints, THG was associated with higher risk of infection (OR: 1.49, SUCRA: 79% vs. 54%), cytomegalovirus infection (OR: 1.04; SUCRA: 40% vs. 37%), de novo diabetes (OR: 1.10; SUCRA: 90% vs. 30%), and malignancy (OR: 8.40; SUCRA: 89% vs. 6%) compared to ATG-F. A subgroup analysis of patients at high risk for immunologic complications revealed similar results, but THG performed better for graft loss (OR: 0.82; SUCRA: 68% vs. 54%).Conclusion: ATG-F seemed to be more effective than THG in improving the short-term kidney transplantation outcomes. Prospective head-to-head comparison of THG and ATG-F with larger sample sizes and longer follow-up is still required.

Economic impacts of alternative kidney transplant immunosuppression: A national cohort study.

Understanding the economic implications of induction and maintenance immunosuppression (ISx) is important in developing personalized kidney transplant (KTx) care. Using data from a novel integrated data set including financial records from the University Health System Consortium, Medicare, and pharmacy claims (2007-2014), we estimated the differences in the impact of induction and maintenance ISx regimens on transplant hospitalization costs and Medicare payments from KTx to 3years. Use of thymoglobulin (TMG) significantly increased transplant hospitalization costs ($12006; P=.02), compared with alemtuzumab and basiliximab. TMG resulted in lower Medicare payments in posttransplant years 1 (-$2058; P=.05) and 2 (-$1784; P=.048). Patients on steroid-sparing ISx incurred relatively lower total Medicare spending (-$10880; P=.01) compared with patients on triple therapy (tacrolimus, antimetabolite, and steroids). MPA/AZA-sparing, mammalian target of rapamycin inhibitors-based, and cyclosporine-based maintenance ISx regimens were associated with significantly higher payments. Alternative ISx regimens were associated with different KTx hospitalization costs and longer-term payments. Future studies of clinical efficacy should also consider cost impacts to define the economic effectiveness of alternative ISx regimens.

Use of Thymoglobulin for Graft Versus Host Disease Prophylaxis Does Not Increase the Incidence of Clostridium Difficile Infection in Recipients of Allogeneic Stem Cell Transplant Recipients

Introduction: Clostridium difficile (C.diff) colitis (CDI) continues to be a common complication in recipients of allogeneic stem cell transplantation (AlloSCT). Multiple risk factors were associated with CDI in this patient population including prior CDI, antibiotic prophylaxis and therapy, acute graft versus host disease (aGVHD), etc. Our aim in this study was to evaluate the effect of thymoglobulin used in GVHD prophylaxis on the incidence of CDI in patients undergoing AlloSCT.Methods: We studied 3 consecutive cohorts of AlloSCT recipients. Group1- related donor AlloSCT without thymoglobulin (N=100, transplanted 3/2010-12/2013); group 2 - unrelated donor AlloSCT with thymoglobulin (N=110, transplanted 4/2012-12/2013); and group 3 - unrelated AlloSCT without thymoglobulin (N=100, transplanted 12/2009-12/2011). Majority of patients except three in group 3 were diagnosed with CDI with a PCR based test.Results: All 3 groups were similar with respect to the baseline characteristics (Table 1). The median follow up for the 3 groups was 2 years.At a median follow up of 2 years the incidence of CDI in the three groups were 19%, 26%, 28% respectively, p=0.2 (table 2). The incidence of CDI prior to aGVHD was similar in three groups (18/100, 25/110 and 19/100 in groups 1, 2 and 3 respectively). The incidence of CDI after development of aGVHD was higher in group 3 (1/100, 4/110 and 9/100 p=0.06 in groups 1, 2 and 3 respectively).The incidence of Grade II-IV aGVHD was significantly higher in group 3 (63%) as compared to groups 1 and 2 (49 and 41%) p=0.006 (Table 2). Similarly the incidence of any grade GI GVHD was higher in group 3 (44% Vs 23% and 24%) p=0.0009. The median time to development of aGVHD was similar in all three groups (28 days in groups 1, 31 days in group 2 and 26 days in group 2).Multivariable analysis revealed that none of the factors examined (age, sex, diagnosis, intensity of conditioning, type of transplant, use of thymoglobulin, acute GVHD) was related to development of CDI. Development of GI GVHD tended to increase the risk of subsequent CDI (40% vs 27%, p=0.06). Development of CDI did not increase the risk of development of subsequent GI GVHD (30% vs. 26%). Use of thymoglobulin improved two year overall survival in patients undergoing unrelated transplant (p=0.006).Conclusion: Thymoglobulin use did not affect the overall incidence of CDI in recipients of Allo-SCT. There is a trend towards increased incidence of late onset CDI in patients undergoing unrelated Allo-SCT and not recieving thymoglobulin probably because of higher incidence of GVHD and steroid use. There was no difference in the incidence of CDI in related vs. unrelated transplant recipients. Use of thymoglobulin improved survival in recipients of unrelated Allo-SCT.Table 1Baseline Characteristics:Related (N=100)unrelated with Thymo (N=110)Allo unrelated without Thymo (N=100)P-valueAgeMedian545852NSGenderF424751NSM586349RaceCaucasian839991NSOther17119Conditioning regimenMyeloablative765963NSRIC245137DiagnosisLeukemia476156NSLymphoma302120MDS122011Other11813Source of stem cellsBM9610NSPBSC9110490HLA match10/10947171NS*9/10226218/10138Haploidentical4GVHD** ProphylaxisTac/MMF97100Tac/MMF/Thymo101Tac/Sirolimus/Thymo9*No difference in HLA match between the groups 2 and 3.**Tac (Tacrolimus); MMF (Mycophenolate Mofetil); THYMO (Thymoglobulin).Table 2Results:Groups1. Related2. Unrelated with Thymo3. unrelated without ThymoP valueIncidence of aGVHD II-IV48%41%63%p=0.006Incidence of GI GVHD23%23.6%44%p=0.0009Use of systemic steroids38%32%61%p=0.0001Overall Incidence of CDI19/100 (19%)29/110 (26%)28/100 (28%)p=0.20Incidence of CDI prior to GVHD18/100 (18%)25/110 (22%)19/100 (19%)NSIncidence of CDI after onset of GVHD1/100 (1%)4/110 (3.6)%9/100 (9%)p=0.06Median Overall survival at 2 year f/u68%52%46%p=0.0057 DisclosuresDeol:Bristol meyer squibb: Research Funding. Lum:Karyopharm Therapeutics Inc: Equity Ownership; Transtarget.Inc: Equity Ownership. Revankar:Actelion, Merck, Gilead, Astellas: Research Funding; Dara biosciences: Consultancy. Chandrasekar:Merck, Glaxo, Chimerix,: Research Funding.

Impact of Lymphocyte Depleting Antibody(LDA) On Rate of Acute Rejection (AR) in Patients With Delayed Graft Function (DGF).

Introduction: DGF impacts AR & graft survival in kidney transplantation (KTx). The KDIGO guideline suggest use of LDI when DGF is likely; but there is no robust data. The impact of LDI on risk of AR in patients with&without DGF was evaluated using OPTN registry. Methods: Adults receiving cadaver kidneys between 2002-11 were studied. Treated AR at 12 months post-KTx was analyzed per known risk factors (RFs) including recipient race, HLA 5/6 antigen mismatch, repeat transplant, ABOi, PRA >0%, ECD organ, cold time > 24 hours and DGF. Multivariable logistic regression model was fit to the data to evaluate whether the incidence of AR in patients with and without DGF is differentially impacted by the use of different induction strategies: No induction, Thymoglobulin(THY), alemtuzumab(C1H) and IL-2 receptor antagonists(IL2-Ra). Results: 73,984 patients were included. RFs by antibody induction are presented in Table 1. Odds of AR was significantly higher in patients who had DGF vs no DGF (Adjusted OR [aOR] =1.95; 95% CI=1.85-2.05), independent of known RFs for AR.Table: No Caption available.However, the impact of DGF was differentially affected by AI strategy (two-way interaction: p<0.001), represented graphically in Figure 1. Adjusted incidence of AR was similar in all groups of patients who had no DGF. In DGF group, AR was significantly lower in THY or C1H vs no induction (aOR=0.65; 95% CI=0.59-0.73 and aOR=0.72; 95% CI=0.60-0.85, respectively) while the incidence of AR remained similar in IL2-Ra vs no induction (aOR=1.12; 95%CI 0.99-1.26).Figure: No Caption available.Conclusion: DGF is an important risk factor for AR. The use of LDI significantly reduces the risk of AR in adult deceased donor renal transplant recipients who develop DGF. We recommend the routine use of LDI when the anticipated risk of DGF is high.

A Comparison of Outcomes Between OKT3 and Antithymocyte Globulin for Treatment of Steroid-Resistant Rejection in Hepatitis C Liver Transplant Recipients

The treatment of steroid-resistant rejection (SRR) is associated with severe recurrent hepatitis C virus (HCV) infection after liver transplantation (LTx). After OKT3 was recently withdrawn from the market, thymoglobulin (TG) became the principal treatment for SRR. A retrospective analysis of 32 HCV patients who were treated for SRR with OKT3 (n=15) or TG (n=17) using yearly protocol liver biopsies. Mean follow-up was 4.3 years (OKT3) and 3.2 years (TG). We compared both groups for patient survival, graft loss, and severity of HCV recurrence, manifested as the mean stage of fibrosis (MSF). Patient survival at 1, 2, and 5 years after LTx was 80%, 73%, and 67% in the OKT3 group and 82%, 77%, and 64% in the TG group, respectively. At 2 years after LTx, the graft losses were 3 versus 4 in the OKT3 and TG groups, respectively. At years 1 and 2, the MSF in the OKT3 group was 1.9 and 2.3 versus 2.4 and 2.8 in the TG group, respectively. None of the differences between both groups was statistically significant. There was no significant difference in patient survival, graft loss, or severity of recurrent HCV, measured as MSF, between both groups.

A Comprehensive and Quantitative Analysis of the Major Specificities in Rabbit Antithymocyte Globulin Preparations

Antithymocyte globulin (ATG) preparations are used for treatment and prevention of graft rejection episodes, graft versus host disease and aplastic anemia. The immunomodulatory and immuosuppressive properties of ATGs are mediated by their interaction with a large variety of antigens expressed on immune and nonimmune cell populations. We have conducted a comprehensive analysis on antibody specificities contained in rabbit ATGs in clinical use, ATG-Fresenius (ATG-F) and Thymoglobulin (THG). We have used retroviral expression cloning to identify novel ATG antigens and demonstrate that together with ATG antigens described earlier, these molecules account for the majority of ATG antibodies directed to human cells. Moreover, we have employed cell lines engineered to express antigens at high levels to quantify the antibodies directed to each ATG antigen. We have used cell lines expressing the T cell receptor complex, CD2 and CD28 to remove antibodies to these antigens from ATG preparations and demonstrate that this treatment abrogated the ability of ATGs to induce activation and forkhead box P3 expression in T cells. Comprehensive information and differences on the antigens targeted by ATG-F and THG as well as novel approaches to assess their functional properties are the basis for a better understanding of their immunomodulatory capacities and might eventually translate into improved ATG-based regimen.

Antithymocyte Antibody–Induced Coagulopathy in Renal Transplant Recipients

BackgroundAntithymocyte antibody (ATA) remains the most commonly used induction immunosuppressive agent in renal transplantation (RT). To date, few case reports of ATA-induced coagulopathy exist. MethodsWe performed a single-center, retrospective analysis of renal transplant recipients (RTRs) who underwent RT followed by ATA therapy between 2007 and 2011. The protocol used for deceased donor and unrelated living donor recipient immunosuppression was Thymoglobulin (TMG), methylprednisolone, Cellcept, Prograf, and Rapamune. In related living donor recipients, Simulect (SIM) was substituted for TMG. The international normalized ratio (INR) was routinely checked on days 0 and 2, and thereafter at the discretion of the surgeon. RTRs were transfused packed red blood cells (PRBCs) or fresh frozen plasma (FFP) at the discretion of the surgeon. ResultsDuring the study period, 257 RTs were performed at our institution. The following 18 RTR were excluded: simultaneous kidney and pancreas transplant recipients (4), RTRs on warfarin at the time of admission (2), RTRs who received OKT3 (2), and RTRs with INR ≥ 1.2 at the time of admission (10). Of the remaining 239 RTR, 208 (87%) underwent TMG induction therapy; 31 RTR (13%) underwent SIM induction therapy. The mean INR peaked in both groups on day 4 but was higher in TMG recipients (TMG 1.35, SIM 1.20). FFP was transfused in 65 TMG (31%) and 3 SIM (10%) recipients (P = .01); PRBCs were transfused in 88 TMG (44%) and 6 SIM (19%) recipients (P = .02). No patients returned to the operating room for bleeding complications within 7 days of RT. Patient age, gender, ethnicity, and diabetes status were not statistically significant factors in the development of coagulopathy. ConclusionTMG administration is associated with coagulopathy. Using an INR screening protocol and an aggressive transfusion protocol, bleeding complications associated with coagulopathy can be avoided in this higher-risk group.

Adoptive immunotherapy with cytokine-induced killer cells generated with a new good manufacturing practice-grade protocol

We have recently shown that thymoglobulin (TG) efficiently expands cytokine-induced killer (CIK) cells in combination with interferon (IFN)-γ and interleukin (IL)-2 (ITG2 protocol). It is presently unknown whether the infusion of autologous immune effector cells generated by TG, IFN-γ and IL-2 is feasible and safe. Five patients with advanced and/or refractory solid tumors were enrolled in the present phase I/II study. Peripheral blood mononuclear cells (PBMC) collected by leukapheresis were stimulated under good manufacturing practice (GMP)-conditions with IFN-γ, followed by TG and IL-2. After 2-3 weeks in culture, a median of 4.65 × 10(6) immune effector cells per kilogram of recipient's body weight was obtained and infused intravenously. The median time from enrollment into the study to infusion of the expanded CIK cells was 30 days. ITG2 efficiently expanded immune effector cells that comprised both conventional natural killer (NK) cells and CD3(+) CD16(+) CD56(+) CIK cells. One patient with advanced melanoma died because of disease progression before the infusion of CIK cells. The target dose of at least 2.5 × 10(6) CIK cells/kg of recipient's body weight was reached in four out of five evaluable patients. CIK cells were administered intravenously without any measurable toxicity. In vitro, CIK cells exerted lytic activity against cervical cancer cells. The median survival was 4.5 months (range 1-13) from the first infusion of CIK cells. This study has highlighted the feasibility and safety of the administration of CIK cells generated with the ITG2 protocol. Whether CIK cells can help control disease burden in patients with advanced malignancies will be determined in future clinical trials.

Thymoglobuline Is As Effective As Lymphoglobuline in Japanese Patients with Aplastic Anemia Possessing Increased Glycosylphosphatidylinositol-Anchored Protein (GPI-AP) Deficient Cells

Abstract 1339 Background:Thymoglobuline (TG), a rabbit anti-thymocyte globulin (ATG) preparation which has more potent immunosuppressive effects than horse ATG Lymphoglobuline (LG), has been shown to be as effective as LG as both first and second line immunosuppressive therapy (IST) for aplastic anemia (AA) by several retrospective studies. However, recent prospective studies from the U.S. and Europe have shown a lower effectiveness of TG compared to horse anti-thymocyte globulin (ATG). The conflicting results may be due to the heterogeneity in the pathophysiology of AA or in the ethnic backgrounds of the patients evaluated. Small populations of glycosylphosphatidylinositol-anchored protein (GPI-AP)-deficient (GPI-AP−) blood cells are detectable in approximately 60% of patients with newly-diagnosed AA, and are associated with a good response to LG (Blood, 107: 1308, 2006). TG may have comparable effects on LG if the study subjects are limited to AA patients possessing GPI-AP− blood cells. Objectives/Methods: To evaluate the effectiveness of TG in Japanese patients with AA, we retrospectively analyzed the outcomes of TG therapy in 57 patients (25 males and 32 females) with AA (40 with severe AA and 17 with non-severe AA) aged from 17 to 84 (median 58) years. Peripheral blood obtained before therapy was examined for the presence of GPI-AP− cells using flow cytometry with liquid fluorescent aerolysin, which can accurately determine the percentage of GPI-AP− granulocytes, erythrocytes, and monocytes at percentages of less than 0.01%. The cut-off values were defined as >0.003% for granulocytes, >0.005% for erythrocytes, and >0.01% for monocytes based on the analytical results of 57 healthy individuals. Results: The cumulative rate of response after 6 months of TG therapy was 59%. Significant increases in the GPI-AP− cell percentages in at least one of the three lineages were detected in 38 (67%) of the 57 patients before therapy. The response rate in patients with increased GPI-AP− cells (PNH+ patients, 69%) was significantly higher than that in patients without GPI-AP− cells (PNH− patients, 35%, P=0.016). Seventeen percent of PNH+ patients achieved complete remission (CR) within 1 year, while only 12% of PNH− patients achieved a CR. 97% of PNH+ and 84% of PNH− patients were alive at the median time of 1 year after the therapy. The response rate in PNH+ patients was comparable to that in PNH+ patients treated with LG (70%) in our recent prospective study. Conclusions: TG is therefore considered to be as effective as LG in Japanese adult patients with AA, particularly in PNH+ AA patients where immune pathophysiology is definitely involved. Alternative therapies may thus need to be considered for PNH− patients. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Efficacy and Safety of Thymoglobulin Induction as an Alternative Approach for Steroid-Free Maintenance Immunosuppression in Pediatric Renal Transplantation

Given the recent withdrawal of daclizumab (DAC), the safety and efficacy of thymoglobulin (TMG) was tested as an alternative induction agent for steroid-free (SF) immunosuppression in pediatric kidney transplant recipients. Thirteen pediatric renal transplant recipients meeting defined high-risk criteria at transplantation were offered TMG induction and SF immunosuppression with maintenance mycophenolate mofetil and tacrolimus between October 2008 and January 2010. Patients were closely monitored at baseline, 3, 6, 9, and 12 months posttransplant for protocol biopsy and clinical outcomes. Outcomes were compared with 13 consecutively transplanted low-risk patients receiving an established DAC-based SF protocol (Sarwal et al., WA, American Transplant Congress 2003). There was a significant trend for overall decrease in the absolute lymphocyte counts in TMG group (F=5.86, mixed model group effect P=0.02), predominately at 3 months compared with DAC group (0.7±0.6 vs. 2.1±1.0, P=0.0004); however, lymphocyte count was recovered and was back to reference range by 6 months in TMG. There was trend toward more subclinical cytomegalovirus (15% vs. 0%) and BK viremia (17% vs. 0%) in the TMG group, with no differences in the incidence of subclinical Epstein Barr virus viremia (23% vs. 31%) or clinical viral disease. Mean graft function was excellent, and with a minimum follow-up of 6 months, there were no episodes of acute rejection. TMG seems to be a safe alternative induction strategy in patients for SF immunosuppression in pediatric renal transplantation. Extended follow-up and greater enrollment are necessary to fully explore the impact of TMG dosing on viral replication posttransplantation.

Thymoglobulin, interferon-γ and interleukin-2 efficiently expand cytokine-induced killer (CIK) cells in clinical-grade cultures

BackgroundCytokine-induced killer (CIK) cells are typically differentiated in vitro with interferon (IFN)-γ and αCD3 monoclonal antibodies (mAb), followed by the repeated provision of interleukin (IL)-2. It is presently unknown whether thymoglobulin (TG), a preparation of polyclonal rabbit γ immunoglobulins directed against human thymocytes, can improve the generation efficiency of CIK cells compared with αCD3 mAb in a clinical-grade culture protocol.MethodsPeripheral blood mononuclear cells (PBMC) from 10 healthy donors and 4 patients with solid cancer were primed with IFN-γ on day 0 and low (50 ng/ml), intermediate (250 ng/ml) and high (500 ng/ml) concentrations of either αCD3 mAb or TG on day 1, and were fed with IL-2 every 3 days for 21 days. Aliquots of cells were harvested weekly to monitor the expression of representative members of the killer-like immunoglobulin receptor (KIR), NK inhibitory receptor, NK activating receptor and NK triggering receptor families. We also quantified the frequency of bona fide regulatory T cells (Treg), a T-cell subset implicated in the down-regulation of anti-tumor immunity, and tested the in vitro cytotoxic activity of CIK cells against NK-sensitive, chronic myeloid leukaemia K562 cells.ResultsCIK cells expanded more vigorously in cultures supplemented with intermediate and high concentrations of TG compared with 50 ng/ml αCD3 mAb. TG-driven CIK cells expressed a constellation of NK activating/inhibitory receptors, such as CD158a and CD158b, NKp46, NKG2D and NKG2A/CD94, released high quantities of IL-12p40 and efficiently lysed K562 target cells. Of interest, the frequency of Treg cells was lower at any time-point compared with PBMC cultures nurtured with αCD3 mAb. Cancer patient-derived CIK cells were also expanded after priming with TG, but they expressed lower levels of the NKp46 triggering receptor and NKG2D activating receptor, thus manifesting a reduced ability to lyse K562 cells.ConclusionsTG fosters the generation of functional CIK cells with no concomitant expansion of tumor-suppressive Treg cells. The culture conditions described herein should be applicable to cancer-bearing individuals, although the differentiation of fully functional CIK cells may be hindered in patients with advanced malignancies.

Choice of Immunosuppression Influences Cytomegalovirus DNAemia in Cynomolgus Monkey (Macaca fascicularis) Islet Allograft Recipients

This retrospective study reviews the results of our experience with the occurrence of CMV DNAemia in islet cell transplanted cynomolgus monkeys subjected to different immunosuppressive protocols, including induction treatment with thymoglobulin (TMG), with a combination of thymoglobulin and fludarabine (FLUD), with cyclophosphamide, or with daclizumab. CMV DNA in the peripheral blood (CMV DNAemia) of 47 monkeys was quantified by real-time PCR on a weekly to biweekly basis. As compared to other immunosuppressive regimens, and in association with greater decreases in WBC, lymphocyte, CD3+CD4+, and CD3+CD8+ lymphocyte counts, frequent CMV DNAemia occurred earlier (within the first month posttransplant), and was of greater severity and duration in recipients of TMG ± FLUD. Treatment of recipients with alternative induction agents that resulted in less dramatic reductions in WBC and lymphocyte counts, however, resulted in occurrence of CMV DNAemia after postoperative day 60. The frequency, average intensity, duration, and area under the curve (AUC) for CMV DNAemia in animals receiving TMG ± FLUD were 75-100%, 4.02 ± 1.75 copies/ng DNA, 23.0 ± 5.3 days, and 367.0 ± 121.1 days × copies/ng DNA, respectively; corresponding values in animals receiving other treatments (0-44%, 0.19 ± 0.10 copies/ng DNA, 0.5 ± 0.3 days, and 75.4 ± 40.2 days × copies/ng DNA, respectively) were significantly different. The value of WBC, T and B cells at the nadir of cell depletion greatly affects the occurrence of CMV DNAemia. No animals developed CMV DNAemia within the next 3 weeks when the lowest value of WBC, lymphocyte, CD3+, CD3+CD4+, CD3+CD8+, or CD20+ cells was above 4500, 1800, 300, 200, 150, or 300 cells/μl, respectively. Oral valganciclovir prophylaxis did not completely prevent the appearance of CMV DNAemia.

A comparison of Campath and Thymoglobulin as part of the conditioning before allogeneic hematopoietic stem cell transplantation

In vivo T-cell depletion with anti-thymocyte globulin is a commonly used strategy for the prevention of graft-versus-host disease (GVHD) and to avoid rejection after hematopoietic stem cell transplantation (HSCT). We compared 36 patients given Campath (alemtuzumab) as part of the conditioning with a matched cohort of 72 patients receiving Thymoglobulin (TMG). Most patients had a hematologic malignancy beyond first remission. Median age was 55 (1-67). The majority of patients had an unrelated donor (70%) and 82% were given peripheral blood stem cells. Most patients received reduced-intensity conditioning. Graft failure occurred in 8% of the patients in each group. No difference in time-to-engraftment of neutrophils and platelets was found. The cumulative incidence of acute GVHD of any grade was 34% and 53% (P = 0.07), and the incidence of chronic GVHD was 46% and 25% in the Campath and TMG groups, respectively. In multivariate analysis, a low antibody dose was associated with acute and chronic GVHD and Campath was correlated with chronic GVHD. No differences in transplant-related mortality (28% vs. 18%), overall survival (54% vs. 58%), and relapse-free survival (39% vs. 43%) were found between the two groups. No difference in the proportion of T and B lymphocytes during the first year after HSCT was found. TMG and Campath as part of the conditioning result in similar outcome. Campath was associated with less acute but more chronic GVHD.

Comparison Between Lymphoglobuline- and Thymoglobuline-Based Immunosuppressive Therapy as First-Line Treatment for Patients with Aplastic Anemia.

Abstract 3194Poster Board III-131 BackgroundImmunosuppressive therapy (IST) is considered to be the first-line treatment in patients with severe aplastic anemia (AA) who are not eligible for hematopoietic stem cell transplantation (HSCT). Most IST schemes are based on the combination of anti-thymocyte globulin (ATG) plus cyclosporine A (CsA). Differently from other countries, two ATGs have been approved in Spain for AA from 2003 to 2007: Lymphoglobuline (LG) (raised in the sera of horses) and Thymoglobuline (TG) (produced in rabbits). So, during this period of time, the standard therapeutic protocol of the Spanish study group for AA included both options, and the physicians chose LG or TG based on their own wishes. Most published studies in AA are with LG, which is no longer manufactured. Recent limited data have confirmed therapeutic efficacy of TG, but no randomized studies have been performed comparing both products' activity. The aim of this report is to communicate the outcomes of a group of patients with AA who received either a LG- or TG-based scheme as first-line treatment. Patients and methodswe retrospectively investigated the outcome of 110 patients with AA treated with IST at front line between 2003 and 2008. Thirty-five patients (32%) got LG (15 mg/kg/day/x5 days), and 75 patients (68%) got TG (2.5 mg/kg/day/x5 days). All patients also received methylprednisolone and CsA. Response rate (RR) was assessed at post-IST day +90, day +180, and day +365. If complete response (CR) was not reached, patients received a second course of IST, a second-line therapy (HSCT or androgens), or no treatment. When a second course of IST was employed, it included LG at the same dose as in the first course (15 mg/kg/day/x5 days), or TG at a higher dose (3.5 mg/kg/day/x5 days). CR was defined as a neutrophil count >1.5×109/L, a platelet count >100 ×109/L, and a hemoglobin level >120 g/L. Partial response (PR) was defined as a neutrophil count >0.5×109/L, a platelet count >20 ×109/L, and a hemoglobin level >80 g/L. Subgroup analyses were conducted and differences in response were tested using the chi-square statistic test. ResultsAfter the first course of IST, CR was achieved in 31 patients (28%) (group A), and PR in 20 patients (18%). Overall response (OR) was similar for both globulins (LG: 49%, TG: 45%). Thirty-five of the patients who did not reach CR after the first IST course, received a second course of IST (6 with LG and 29 with TG) (group B), and 44 patients underwent a different approach (second-line therapy or no treatment) (group C). After the second course of IST, 14 patients achieved CR (40%) and 11 patients PR (31%). OR was similar for LG (67%) and TG (72%). If we exclude patients in group C, the RR among the remaining 66 patients (who underwent 1 or 2 courses of IST) was 85% (68% CR, and 17% PR). No major drug-related toxicities were reported in the whole group of patients. ConclusionsATG-based schemes with both LG and TG were well tolerated as treatment of patients with AA. OR after first course of IST was similar in the LG and in the TG group (49% versus 45%). RR after second course of IST was also similar when LG and TG were employed (67% versus 72%). After excluding those patients who, not having reached CR after the first course, underwent an approach different from a second course of IST, RR to IST was 85%, with 68% of CR. No statistical differences were found based on the type of ATG administered. The results of this study show that TG is, at least, as effective as LG for the treatment of AA patients. Based on these and other recently published data, the current standard therapeutic protocol of the Spanish study group for AA includes TG at the dose of 3.75 mg/kg/day/x5 days for both the first and, if necessary, second course of IST. To our knowledge, no reports are available in the medical literature comparing the outcome of patients with AA who received LG or TG as the first-line therapy for AA. So, in spite of the fact that our study is retrospective and not randomized, we think our data are unique and very useful for helping physicians in switching from LG to TG. DisclosuresNo relevant conflicts of interest to declare.

Thymoglobulin induction in liver transplant recipients with a tacrolimus, mycophenolate mofetil, and steroid immunosuppressive regimen: A five-year randomized prospective study

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 TMG+ group, and 49 patients were randomly allocated to the TMG- group. In both groups, Tac was given orally at the initial daily dose of 0.075 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 TMG- 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 TMG+ 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.