A prospective study on efficacy and tolerance of antithymocyte globulin Fresenius versus thymoglobuline Merieux after renal transplantation

Comparison of Thymoglobulin and Grafalon as Induction Agents in Renal Transplantation: A Prospective Study

BACKGROUND

Induction immunosuppression is used to reduce the incidence of acute rejection and prevent delayed graft function. The 2 rabbit anti-thymocyte globulins- thymoglobulin and Grafalon (ATG Fresenius) have been commonly used for induction immunosuppression and treatment of acute rejection in solid organ transplantation. There are very few studies comparing the efficacy and side effects of both the anti-thymocyte globulins therefore this prospective study comparing the 2 types of anti-thymocyte globulins would be of clinical interest.

PATIENTS AND METHODS

This prospective single center study was conducted at Rabindranath Tagore International Institute of Cardiac Sciences, Kolkata, India from April 2019 to June 2020. Sixty-two ABO-compatible renal transplant recipients were included in the study. They were divided in 2 groups of 31 patients each. One group received thymoglobulin (3 mg/kg) and the second group received Grafalon (6 mg/kg). All patients were followed up for 12 months and the 2 groups were compared for incidence of rejections, infections, graft function, patient survival, and graft survival.

RESULTS

There was no significant difference in the incidence of rejections, infective episodes, graft function, posttransplant diabetes mellitus, graft survival and patient survival in thymoglobulin or Grafalon groups. The hematological parameters were similar in both groups at 7 days, 1 month, and 6 months of follow-up. The absolute lymphocyte count was significantly lower in the thymoglobulin group at 12 months posttransplant.

CONCLUSIONS

Thymoglobulin and Grafalon were found to be equivalent in terms of safety and efficacy in short term, with no difference in rejections, infections, graft survival, or patient survival.

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.

Effectiveness and safety of two different antithymocyte globulins used in induction therapy in kidney transplant recipients: A single-center experience

BACKGROUND

Antithymocyte globulin (ATG) is widely used as an induction therapy after kidney transplantation. The present study aimed to compare the effectiveness and safety of induction therapy between two ATG formulations, Grafalon (Fresenius® ) and Thymoglobulin (Sanofi® ), in kidney transplant patients.

METHODS

This study included 140 consecutive kidney transplant recipients, 71 treated with Grafalon and 69 treated with Thymoglobulin, in the period between February 2010 and January 2018. To optimize therapy costs, considering the periodically limited drug availability and the substantial drug waste in the case of Grafalon, Thymoglobulin induction was introduced into the immunosuppressive protocol.

RESULTS

The ATG total dose in mg/kg of body mass [median: 5.3 (3.7-7.1) vs 8.6 (4.3-17.3); P < .001] was significantly lower in the Thymoglobulin subgroup. There were 7 (5%) graft losses and 15 (10.7%) deaths during the first 12 months, with 66.7% of deaths due to infection complications. Patients treated with Thymoglobulin were characterized by a lower absolute lymphocyte count at day 7 and during the 12 months of follow-up, compared with the Grafalon group [236 (205-267) vs 483 (372-594), respectively; P < .001]. Logistic regression analysis showed that a lymphocyte count < 200/µL at day 7 (OR = 10.5; 95%CI, 1.6-69.0; P = .01) and age >50 years (OR = 14.6; 95%CI, 1.4-155.0; P = .03), but not type of ATG, independently increased the risk of death due to infection. The 12-month acute rejection rate was higher in the Grafalon group (25.3% vs 10.1%, P = .02).

CONCLUSION

Treatment with Thymoglobulin in kidney transplant recipients resulted in more pronounced lymphopenia and a lower 12-month rate of acute rejection.

A review on comparing two commonly used rabbit anti-thymocyte globulins as induction therapy in solid organ transplantation

INTRODUCTION

Two rabbit anti-thymocyte globulins (ATGs) (Thymoglobulin™ and ATG-Fresenius (ATG-F)™) have been used commonly for induction immunosuppression and treatment of acute rejection in solid organ transplantation. Therefore, literature review on comparative efficacy and side-effect profile of them would be of clinical interest.

AREAS COVERED

This review evaluated all comparative studies in English language, focusing on the solid organ transplant patients who received Thymoglobulin or ATG-F as induction therapy. This review concluded that compared to ATG-F, Thymoglobulin possibly provides better protection against acute rejection and improves patient and graft survival but may result in more cytomegalovirus infection and post-transplant malignancy. Thymoglobulin produced more leukocyte depletion with a greater delay to recover, while ATG-F had more reduction effects on platelet and erythrocyte counts with an increased need to erythropoiesis-stimulating agent.

EXPERT OPINION

The benefits of induction therapy with ATGs must be weighed against the costs and post-transplant complications. It is suggest that there is no substantial clinical difference between these two rabbit ATGs and each may be considered as induction therapy for solid organ transplantation based on availability and drug cost. Of special importance is adding antiviral therapy to the treatment regimen of patients who receive ATGs as induction therapy.

The effect of different ATG preparations on immune recovery after allogeneic hematopoietic stem cell transplantation for severe aplastic anemia

Anti-thymocyte globulin (ATG) is widely used in the conditioning regimen before allogeneic stem cell transplantation for aplastic anemia. However, there are several different preparations of ATG and little is known about the difference of their effects on transplantation outcome. Therefore, in this study, we retrospectively compared the effect of two different rabbit ATG preparations [Thymoglobulin (ATG-G) and ATG-Fresenius (ATG-F)] on immune recovery and cytomegalovirus infection after transplantation. The conditioning regimen was a combination of fludarabine, cyclophosphamide, and ATG. Low dose total body irradiation was added in alternative donor transplantation. Four patients received ATG-F at 5 mg/kg/day from day -7 to day -3, whereas ATG-G was given at 2.5 mg/kg/day from day -5 to day -2 in three patients. There was no graft rejection and no grade II-IV acute graft-versus-host disease. All three patients in the ATG-G group developed positive cytomegalovirus antigenemia including two with high-grade antigenemia, whereas two of the four patients in the ATG-F group were persistently negative. Immunological evaluation on day 60 revealed that both CD4+ and CD8+ T-cell recoveries were delayed in the ATG-G group. These findings suggested that ATG-G has a stronger immunosuppressive activity than the ATG-F with a dose ratio of 1:2.5.

LONG-TERM TOXICITY OF ANTITHYMOCYTE GLOBULIN INDUCTION MAY VARY WITH CHOICE OF AGENT: A SINGLE-CENTER RETROSPECTIVE STUDY

BACKGROUND

Antithymocyte globulin (ATG) preparations are frequently used as induction treatment in renal transplantation, but little is known about the clinical equivalence of these different agents. We performed a retrospective, single-center study to compare the long-term clinical effects of ATG Fresenius (ATGF) and Thymoglobulin (SangStat, Fremont, CA) in renal transplant recipients.

PATIENTS AND METHODS

A total of 194 consecutive renal transplant recipients were included who had undergone transplantation in our center between June 1993 and April 2001 and had received ATGF or Thymoglobulin as induction treatment.

RESULTS

A total of 129 patients received ATGF and 65 patients received Thymoglobulin. Thirty patients (23%) in the ATGF group demonstrated cytomegalovirus (CMV) disease, whereas 24 patients (37%) in the Thymoglobulin group demonstrated CMV (P =0.02). Five patients (3.9%) in the ATGF group and eight patients (12.3%) in the Thymoglobulin group developed posttransplant malignancy (P =0.01). Five patients (3.9%) in the ATGF group and nine patients (13.8%) in the Thymoglobulin group died during follow-up (P =0.005). Cox regression analysis revealed that Thymoglobulin was an independent predictor of CMV disease (relative risk [RR] 2.16, confidence interval [CI] 95% [1.04-4.48]), malignancy (RR 2.16, CI 95% [1.04-4.48]), and death (RR 4.14, CI 95% [1.36-12.6]).

CONCLUSION

In renal transplant recipients, induction therapy with Thymoglobulin seems to be associated with a significantly greater incidence of CMV disease, malignancy, and death compared with ATGF.

Use of antithymocyte globulin for treatment of steroid-refractory acute graft-versus-host disease: an international practice survey

Antithymocyte globulin (ATG) is accepted as a treatment option for steroid-refractory acute graft-versus-host disease (GVHD). We conducted an international survey to determine how steroid refractoriness is defined and how ATG is used in clinical practice. Responses were received from 153 centers in 36 countries. The most common threshold steroid dose to define steroid refractoriness was 2 mg/kg/day (67% of respondents), and the median duration of treatment before failure was declared varied from 3 to 5.5 days, depending on whether failure was defined as 'progressed', 'not improved' or 'not resolved'. The threshold corticosteroid dose was significantly higher in pediatric centers than in adult or combined programs (P = 0.003). ATG was used routinely for treatment of steroid-refractory GVHD by 67% of the respondents. Horse ATG was used more frequently than rabbit ATG overall (50% vs 24%, P < 0.001), and predominance of horse ATG was most evident in the western hemisphere, in small- to medium-sized centers, and in pediatric centers. A wide variety of dose schedules for both drugs was reported. We conclude that there is some degree of variation in the definition of steroid refractoriness, especially between pediatric and nonpediatric programs, and no consensus has emerged in identifying the optimal ATG dose schedule in this setting.

A quantitative flow cytometry assay for the preclinical testing and pharmacological monitoring of rabbit antilymphocyte globulins (rATG)

Rabbit antilymphocyte or antithymocyte globulins (rATG) are currently used as immunosuppressive agents in clinical organ and bone marrow transplantation, but because of differences in antigen source and purification processes between manufacturers, determination of the dose to be administered remains empirical. Dosage may be adjusted to peripheral blood T cell counts or limited by side effects such as neutropenia or thrombocytopenia. We report here a measurement by indirect immunofluorescence of the amount of antibodies from rATG that bind to different blood cell types. A concentration-related immunofluorescence signal was obtained with reasonable replicability, allowing comparison of different rATGs by reference to the same rATG batch as internal standard. Ratios of antilymphocyte to undesirable antibodies (directed against antigens expressed on neutrophils, platelets or red cells) could be calculated for each rATG preparation. Finally, the method is applicable to the measurement of free antibodies in sera from patients treated with rATG and to the analysis of the effects of in vivo absorption of rATG during its administration. Marked differences in antibody content per mg of rIgG account for the differences in rATG dosage that were empirically established for clinical applications.