Induction therapy of basiliximab versus antithymocyte globulin in renal allograft: a systematic review and meta-analysis. Clin Exp Nephrol. 2018;22:684-693. [PMID: 28986715 DOI: 10.1007/s10157-017-1480-z]

Inefficiency Rates of Biological Immunosuppressive Induction Agents Used in Organ Transplantation: A Pharmacovigilance Study

Effective immunosuppressant pharmacotherapy is essential for successful organ transplantation. Background/Objectives: Generally, induction therapy includes basiliximab (BAS) or anti-thymocyte globulin (THY). However, other biological molecules have been used to accelerate firm immunosuppression. A reduced effectiveness of these induction agents increases the risk of graft rejection. This study aims to evaluate the ineffectiveness rate of biological molecules based on spontaneous reports uploaded to the EudraVigilance database. Methods: Specific topics related to the safety profiles of alemtuzumab, BAS, belatacept, and THY were analyzed. A total of 23 preferred terms describing drug resistance, drug ineffectiveness, and transplant rejection were used as the inclusion criteria. Descriptive and disproportionality analyses were performed. Results: Regarding the four molecules, 18,564 safety reports were communicated, with n = 5089 (27.4%) for THY and n = 3469 (18.7%) for BAS. Most adverse drug reactions (ADRs) for THY, BAS, and belatacept affected the adult male population. As expected, the majority of the ADRs were linked to infections, followed by general disorders. BAS presented higher probabilities of drug resistance and transplant rejection being reported among the four molecules. A higher probability of reporting drug ineffectiveness was noted for THY than for the other molecules. Conclusions: All the molecules showed small frequencies regarding resistance. As expected, transplant rejection was more frequently reported for all molecules (especially for BAS), accompanied by a notable variability in reporting frequencies. However, a causal relationship between the reported adverse reactions and drug efficacy cannot be established based on the present results. Further real-world evidence studies will enhance our understanding of the safety and efficacy of these drugs in transplant patients.

Efficacy and Safety of Induction Therapy in Kidney Transplant Recipients: A Propensity Score Matching Analysis in a Multicenter Retrospective Observational Study

BACGROUND

This study aimed to compare the efficacy and safety of induction treatments in kidney transplant recipients.

METHODS

A total of 2564 kidney transplant recipients from 15 transplant centers were included in the study and were categorized into 3 groups for comparison. Group 1: No induction (n = 222, 8.7%), Group 2: Anti-T lymphocyte globulin (ATLG, n = 1794, 70%) and Group 3: Basiliximab (n = 548, 21.4%). The results were compared across 3 post-transplant periods: the first month, the 1st to 6th month, and the 6th to 12th month.

RESULTS

Prior to propensity score matching (PSM), there were no significant differences in graft/patient survival, BKV (polyomavirus) incidence, or rejection rates during the first month among the groups. However, the Anti-T lymphocyte globulin (ATLG) group exhibited higher rates of developing donor-specific antibodies (DSA), cytomegalovirus (CMV) infection, general infections, and delayed graft function (DGF), along with higher rejection rates at 1 month post-transplant. After the PSM analysis, rejection rates (which were higher in the ATLG group compared to the Basiliximab group only in the first month), graft/patient loss, and BKV rates were comparable. Infection, CMV, and DSA rates remained elevated in the ATLG group. Clinical results of groups 1 and 3 were similar.

CONCLUSIONS

This study shown that ATLG provides positive clinical results despite increased infection and DSA formation in patients with high immunological risk, whereas the efficacy and necessity of induction in patients with low-moderate immunological risk is debatable.

Pulmonary Immunocompromise in Solid Organ Transplantation

This article reviews the multitude of factors contributing to immune dysfunction and pulmonary infection risk in solid organ transplant recipients and references relevant clinical scientific reports. The mechanisms of action of individual immunosuppressive agents are explained, and the clinical effects of these drugs are compared. In addition, specialized methods to assess the net state of immunosuppression in individual transplant recipients and their limitations are discussed.

Cost-Effectiveness Analysis of Pharmacological Treatment for Adult Kidney Transplant Recipients in Colombia

OBJECTIVES

To evaluate cost-effective pharmacological treatment in adult kidney transplant recipients from the perspective of the Colombian health system.

METHODS

A decision tree model for the induction phase and a Markov model for the maintenance phase were built. A review of the clinical literature was conducted to extract probabilities, and the life-years were used as the outcome. Costs were calculated using the administrative databases. The evaluating treatment schemes are organized by groups of evidence with direct comparisons.

RESULTS

In the induction phase, anti-thymocyte immunoglobulin+ methylprednisolone is dominant, more effective, and less expensive, compared with basiliximab+methylprednisolone. In the maintenance phase, azathioprine (AZA) is dominant in contrast to mycophenolate mofetil (MFM) both with cyclosporine (CIC)+ corticosteroids (CE); CIC is dominant relative to sirolimus (SIR) and tacrolimus (TAC) (both with MFM+CE or AZA+CE), and TAC is dominant compared with SIR (in addition with MFM+CE or mycophenolate sodium [MFS]+CE); MFM is dominant in relation to MFS and everolimus, and SIR is more effective MFM but it does not exceed the threshold (in sum with TAC+CE); MFS and MFM are dominant relative to everolimus, and SIR is more effective than MFM, but it does not exceed the threshold (in addiction with CIC+CE); MFM is dominant in relation to TAC (in sum with SIR+CE), and CIC+AZA+CE is dominant in relation to TAC+MFM+CE.

CONCLUSIONS

The base-case results for all evidence groups are consistent with the different sensitivity analyses.

Positive Long-Term Outcome of Kidney Allocation via Acceptable Mismatch Program in Highly Sensitized Patients

Introduction

Eurotransplant established the acceptable mismatch (AM) program to facilitate timely kidney transplantations of highly sensitized patients, but long-term granular clinical and immunological outcomes regarding overall graft survival and de novo DSA (dnDSA) formation are still intensively researched. The right choice of induction therapy in patients with differing immunological risk is not conclusively determined, as well as the impact of human leukocyte antigen (HLA) epitope matching on dnDSA formation.

Methods

This monocentric, retrospective study analyzed 94 patients transplanted within the AM program between 2000 and 2019 compared to case-control matched cohorts of non- (PRA 0-5%; PRA-0) and intermediately sensitized (PRA 6-84%; PRA-6/84) patients transplanted through Eurotransplant Kidney Allocation System.

Results

Estimated 10-year overall graft survival between the PRA-0 and AM cohorts was similar, whereas PRA-6/84 was significantly disadvantageous compared to PRA-0. Estimated 10-year incidence of antibody-mediated rejection rates was significantly lower in the PRA-0 group compared to AM and PRA-6/84 groups. Compared to the AM group, estimated incidence of de novo donor-specific antibody (dnDSA) was significantly lower in PRA-0 patients, with no differences between the AM and PRA-6/84 cohorts. The PRA-6/84 cohort was the only subgroup in which interleukin-2 receptor antagonist (IL2RA) induction was associated with longer overall graft survival, patient survival, and graft survival compared to depleting induction (ATG or OKT3). Broad HLA-A, -B, -DR mismatches (mmABDR) and HLA epitope mismatches determined by Eplets and PIRCHE-II were predictive for dnDSA formation in the total cohort, and the AM subgroup.

Discussion

The high efforts expended on AM patients are justified to allow timely organ transplantation with acceptable risk profile and non-inferior outcomes. IL2RA induction in intermediately sensitized patients is associated with superior overall graft survival, patient survival, and graft survival compared to ATG/OKT3 induction, without negative effects on rejection episodes or dnDSA formation. In silico epitope matching might further help reduce dnDSA formation, particularly in high-risk AM patients.

Effects of Antithymocyte Globulin, Basiliximab, and Induction-Free Treatment in Living Donor Kidney Transplant Recipients on Tacrolimus-Based Immunosuppression

OBJECTIVES

Induction treatment in renal transplant is associated with better graft survival. However, intensified immunosuppression is known to cause unwanted side effects such as infection and malignancy. Furthermore, the effects of the routine use of immunosuppressants in low-risk kidney transplant recipients are still not clear. In this study, we assessed the first-year safety and efficacy of induction treatment.

MATERIALS AND METHODS

We examined first living donor kidney transplant patients who were on tacrolimus based immunosuppression therapy. We formed 3 groups according to the induction status: antithymocyte globulin induction, basiliximab induction, and no induction. We collected outcome data on delayed graft function, graft loss, creatinine levels, estimated glomerular filtration rates, acute rejection episodes, hospitalization episodes, and infection episodes, including cytomegalovirus infection and bacterial infections.

RESULTS

We examined a total of 126 patients (age 35 ± 12 years; 65% male). Of them, 25 received antithymocyte globulin, 52 received basiliximab, and 49 did notreceive any induction treatment. We did not observe any statistically significant difference among the 3 groups in terms of acute rejection episodes, delayed graft function, and first-year graft loss. The estimated glomerular filtration rates were similar among the groups. Overall bacterial infectious complications and cytomegalovirus infection showed similar prevalence among all groups. Hospitalization was less common in the induction-free group.

CONCLUSIONS

In low-risk patients, induction-free regimens could be associated with a better safety profile without compromising graft survival. Therefore, induction treatment may be disregarded in first living donor transplant patients who receive tacrolimusbased triple immunosuppression treatment.

The use of lymphocyte-depleting antibodies in specific populations of kidney transplant recipients: A systematic review and meta-analysis

BACKGROUND

Recommendations of the use of antibody induction treatments in kidney transplant recipients (KTR) are based on moderate quality and historical studies. This systematic review aims to reevaluate, based on actual studies, the effects of different antibody preparations when used in specific KTR subgroups.

METHODS

We searched MEDLINE and CENTRAL and selected randomized controlled trials (RCT) and observational studies looking at different antibody preparations used as induction in KTR. Comparisons were categorized into different KTR subgroups: standard, high risk of rejection, high risk of delayed graft function (DGF), living donor, and elderly KTR. Two authors independently assessed the risk of bias.

RESULTS

Thirty-seven RCT and 99 observational studies were finally included. Compared to anti-interleukin-2-receptor antibodies (IL2RA), anti-thymocyte globulin (ATG) reduced the risk of acute rejection at two years in standard KTR (RR 0.74, 95%CI 0.61-0.89) and high risk of rejection KTR (RR 0.55, 95%CI 0.43-0.72), but without decreasing the risk of graft loss. We did not find significant differences comparing ATG vs. alemtuzumab or different ATG dosages in any KTR group.

CONCLUSIONS

Despite many studies carried out on induction treatment in KTR, their heterogeneity and short follow-up preclude definitive conclusions to determine the optimal induction therapy. Compared with IL2RA, ATG reduced rejection in standard-risk, highly sensitized, and living donor graft recipients, but not in high DGF risk or elderly recipients. More studies are needed to demonstrate beneficial effects in other KTR subgroups and overall patient and graft survival.

Impact of Induction Immunosuppressants on T Lymphocyte Subsets after Kidney Transplantation: A Prospective Observational Study with Focus on Anti-Thymocyte Globulin and Basiliximab Induction Therapies

Induction immunosuppressive therapy for kidney transplant recipients (KTRs) primarily includes interleukin-2 receptor antagonists, such as basiliximab (BXM) or lymphocyte-depleting agents, and anti-thymocyte globulin (ATG). This study aimed to investigate their effects on T cell dynamics during the early post-transplantation period. This prospective observational study included 157 KTRs. Peripheral blood samples were collected from each patient within 5 days before and 4 and 12 weeks after transplantation. Flow cytometric analysis was performed to assess various T cell subsets whose changes were then analyzed. In the ATG group, CD4+ T cell expression decreased significantly compared with that in the BXM group. However, CD4+CD161+ and CD4+CD25+CD127low T cell expression levels increased significantly. In the CD8+ T cell subset, a decrease in CD8+CD28nullCD57+ and CD8+CCR7+ T cell expression was observed in the ATG group. However, among patients diagnosed with biopsy-proven acute rejection, T cell subset expression did not significantly differ relative to non-rejection cases. In conclusion, ATG induction therapy resulted in more pronounced changes in T lymphocyte subsets than BXM induction, with increased CD4+CD161+ and CD4+CD25+CD127low T cells and an early decrease in CD8+CD28nullCD57+ and CD8+CCR7+ T cells, some of which are associated with acute rejection.

Preventing Rejection of the Kidney Transplant

With increasing knowledge of immunologic factors and with the advent of potent immunosuppressive agents, the last several decades have seen significantly improved kidney allograft survival. However, despite overall improved short to medium-term allograft survival, long-term allograft outcomes remain unsatisfactory. A large body of literature implicates acute and chronic rejection as independent risk factors for graft loss. In this article, we review measures taken at various stages in the kidney transplant process to minimize the risk of rejection. In the pre-transplant phase, it is imperative to minimize the risk of sensitization, aim for better HLA matching including eplet matching and use desensitization in carefully selected high-risk patients. The peri-transplant phase involves strategies to minimize cold ischemia times, individualize induction immunosuppression and make all efforts for better HLA matching. In the post-transplant phase, the focus should move towards individualizing maintenance immunosuppression and using innovative strategies to increase compliance. Acute rejection episodes are risk factors for significant graft injury and development of chronic rejection thus one should strive for early detection and aggressive treatment. Monitoring for DSA development, especially in high-risk populations, should be made part of transplant follow-up protocols. A host of new biomarkers are now commercially available, and these should be used for early detection of rejection, immunosuppression modulation, prevention of unnecessary biopsies and monitoring response to rejection treatment. There is a strong push needed for the development of new drugs, especially for the management of chronic or resistant rejections, to prolong graft survival. Prevention of rejection is key for the longevity of kidney allografts. This requires a multipronged approach and significant effort on the part of the recipients and transplant centers.

Effects of Induction Therapy on Graft Functions in Terms of Immunologic Risk

BACKGROUND

Advances in immunosuppressive therapies and surgical techniques have led to a significant reduction in the incidence of rejection within 1 year after kidney transplantation. Immunologic risk is an important factor affecting graft functions and guiding the clinician in the selection of induction therapy. The aim of this study was to investigate graft functions based on serum creatinine levels, Chronic Kidney Disease Epidemiology Collaboration (CKD- EPI) and proteinuria levels, frequency of leukopenia, cytomegalovirus (CMV) and BK virus polymerase chain reaction (PCR) positivity in patients with low and high immunologic risk.

MATERIAL AND METHODS

This retrospective study included 80 renal recipients. Recipients were divided into 2 groups: patients at low immunologic risk who received basiliximab only and those with high immunologic risk who received low-dose (1.5 mg/kg for 3 days) antithymocyte globulin and basiliximab.

RESULTS

No significant differences were observed between the 2 risk groups in terms of first, third, sixth, and 12th-month creatinine levels, CKD-EPI, proteinuria levels, leukopenia frequency, and CMV and BK virus PCR positivity.

CONCLUSION

One-year graft survivals did not differ significantly between these 2 treatment modalities. The combined use of low-dose antithymocyte globulin and basiliximab in the induction treatment of patients with high immunologic risk seems promising in terms of graft survival, leukopenia frequency, and CMV and BK virus PCR positivity.

LIS1, a glyco-humanized swine polyclonal anti-lymphocyte globulin, as a novel induction treatment in solid organ transplantation

Anti-thymocyte or anti-lymphocyte globulins (ATGs/ALGs) are immunosuppressive drugs used in induction therapies to prevent acute rejection in solid organ transplantation. Because animal-derived, ATGs/ALGs contain highly immunogenic carbohydrate xenoantigens eliciting antibodies that are associated with subclinical inflammatory events, possibly impacting long-term graft survival. Their strong and long-lasting lymphodepleting activity also increases the risk for infections. We investigated here the in vitro and in vivo activity of LIS1, a glyco-humanized ALG (GH-ALG) produced in pigs knocked out for the two major xeno-antigens αGal and Neu5Gc. It differs from other ATGs/ALGs by its mechanism of action excluding antibody-dependent cell-mediated cytotoxicity and being restricted to complement-mediated cytotoxicity, phagocyte-mediated cytotoxicity, apoptosis and antigen masking, resulting in profound inhibition of T-cell alloreactivity in mixed leucocyte reactions. Preclinical evaluation in non-human primates showed that GH-ALG dramatically reduced CD4+ (p=0.0005,***), CD8+ effector T cells (p=0.0002,***) or myeloid cells (p=0.0007,***) but not T-reg (p=0.65, ns) or B cells (p=0.65, ns). Compared with rabbit ATG, GH-ALG induced transient depletion (less than one week) of target T cells in the peripheral blood (<100 lymphocytes/L) but was equivalent in preventing allograft rejection in a skin allograft model. The novel therapeutic modality of GH-ALG might present advantages in induction treatment during organ transplantation by shortening the T-cell depletion period while maintaining adequate immunosuppression and reducing immunogenicity.

A Bright Horizon: Immunotherapy for Pediatric T-Cell Malignancies

Immunotherapy has transformed the treatment of hematologic malignancies in the past two decades. The treatment of acute lymphoblastic leukemia (ALL), in particular, has been highly impacted by multiple novel immunotherapies. For pediatric patients with T-cell malignancies, translating immunotherapies has proved more challenging due to the complexities of fratricide, risk of product contamination with malignant cells, and concerns over T-cell aplasia. Despite these hurdles, many creative and promising strategies are on the horizon. We review challenges in the development of immunotherapy for T-cell malignancies, strategies to overcome these challenges, as well as therapies currently being investigated and starting to reach the clinic. Immunotherapy will hopefully successfully treat patients with relapsed and refractory T-cell malignancies and may someday be incorporated in up-front protocols in order to prevent relapses.

Adverse Effects of Immunosuppression: Infections

Immunosuppressive therapies are currently indicated for a wide range of diseases. As new agents emerge and indications evolve the landscape grows increasingly complex. Therapies can target pathologic immune system over-activation in rheumatologic or autoimmune disease, or conditioning and graft versus host disease (GVHD) prophylactic regimens may eliminate or inhibit host immune function to improve graft survival and risk of complication in solid organ transplantation (SOT) or hematopoietic stem cell transplantation (HSCT). With immunosuppressive therapy, infections occur. Complex disease states, host factors, and concomitant therapies contribute to a "net state" of immunosuppression that must be considered and may confound perceived increased infection risks in patients receiving treatment.

Antithymocyte globulin is associated with a lower incidence of de novo donor-specific antibody detection in lung transplant recipients: A single-center experience

Purpose

Induction immunosuppression has improved the long‐term outcomes after lung transplant. This is the first report exploring the association of induction immunosuppression with the development of de novo donor‐specific human leukocyte antigen (HLA) antibodies (DSA) in lung transplant recipients (LTR).

Methods

Sixty‐seven consecutive primary LTR were followed for 3 years posttransplant. A total of 41/67 (61%) LTR‐received induction immunosuppression using a single dose of rabbit Antithymocyte Globulin (rATG; 1.5 mg/kg) within 24 h of transplant. All recipients had a negative flow cytometry crossmatch on the day of transplant. Serum samples at 1, 3, 6, and 12 months posttransplant were assessed for the presence of de novo HLA DSA.

Results

De novo HLA DSA were detected in 22/67 (32.8%) LTR within 1‐year posttransplant. Of these, 9/41 (21.9%) occurred in the induction therapy group and 13/26 (50%) in the noninduction group. Class II DSA were detected in 3/41 (7.3%) LTR who received induction compared to 9/26 (34.6%) LTR without induction immunosuppression (p = .005). Differences in overall survival or freedom from chronic lung allograft dysfunction rates between the two groups were not statistically significant.

Conclusion

Induction immunosuppression utilizing a modified regimen of single‐dose rATG is associated with a significant reduction in de novo DSA production in LTR.

The Impact of Different Induction Immunosuppressive Therapy on Long-Term Kidney Transplant Function When Measured by Iothalamate Clearance

Background

Improvement in short-term outcomes after kidney transplant has been achieved by using different induction and maintenance therapeutic approaches. Long-term outcomes have not matched the expectations of the transplant stakeholders. Our study aimed to address the early impact of induction agents on long-term outcome of kidney transplant when measured by iothalamate clearance.

Methods

All adult kidney transplant recipients between January of 2012 and December of 2016 were reviewed. Six hundred forty-nine patients were divided into three groups based on the induction agent (basiliximab, alemtuzumab, and thymoglobulin). Protocoled 4 months and 48 months kidney allograft function evaluations with iothalamate clearance test were compared among the three groups.

Results

Patients who received basiliximab were significantly older with no difference among African American and Caucasians. The 48 months assessment showed significant decline in median iothalamate clearance in basiliximab group at 49 mL/min vs. alemtuzumab group 64.8 mL/min and thymoglobulin 60 mL/min with P = 0.007. The basiliximab group developed a significant higher proteinuria measured by spot urine to creatinine ratio at 48 months.

Conclusions

The use of basiliximab as an induction agent for kidney transplant is associated with significant decline in kidney function 4 years post transplantation when measured by iothalamate clearance.

Treatment options for localised renal cell carcinoma of the transplanted kidney

Currently, there is no consensus among the transplant community about the treatment of renal cell carcinoma (RCC) of the transplanted kidney. Until recently, graftectomy was universally considered the golden standard, regardless of the characteristics of the neoplasm. Due to the encouraging results observed in native kidneys, conservative options such as nephron-sparing surgery (NSS) (enucleation and partial nephrectomy) and ablative therapy (radiofrequency ablation, cryoablation, microwave ablation, high-intensity focused ultrasound, and irreversible electroporation) have been progressively used in carefully selected recipients with early-stage allograft RCC. Available reports show excellent patient survival, optimal oncological outcome, and preserved renal function with acceptable complication rates. Nevertheless, the rarity and the heterogeneity of the disease, the number of options available, and the lack of long-term follow-up data do not allow to adequately define treatment-specific advantages and limitations. The role of active surveillance and immunosuppression management remain also debated. In order to offer a better insight into this difficult topic and to help clinicians choose the best therapy for their patients, we performed and extensive review of the literature. We focused on epidemiology, clinical presentation, diagnostic work up, staging strategies, tumour characteristics, treatment modalities, and follow-up protocols. Our research confirms that both NSS and focal ablation represent a valuable alternative to graftectomy for kidney transplant recipients with American Joint Committee on Cancer stage T1aN0M0 RCC. Data on T1bN0M0 lesions are scarce but suggest extra caution. Properly designed multi-centre prospective clinical trials are warranted.

Effectiveness of serum beta-2 microglobulin as a tool for evaluating donor kidney status for transplantation

Kidney transplantations using expanded criteria donors (ECD) are being increasingly adopted, but no consensus tools are available to evaluate donor kidney status. Beta-2 microglobulin (B2MG) is a marker of kidney function, and herein, we evaluate the usefulness of assessing B2MG to evaluate donor kidney status. Fifty-seven kidney transplantations were performed from March 2017 to April 2019. Medical records were retrospectively reviewed, and relationships between clinical and laboratory variables and transplant outcomes were investigated. Thirty-eight patients received a standard criteria donor kidney and 19 patients an ECD kidney. Ten patients experienced delayed graft function (DGF), but no patient experienced primary nonfunction. Of the parameters studied, only donor renal replacement therapy (RRT) [odds ratio (OR) 24.162; p = 0.018] and donor serum B2MG (OR 22.685; p = 0.022) significantly predicted DGF. The presence of either of these two risk factors can better reflect the condition of the donor than previous classification. However, on their last follow-up creatinine and estimated glomerular filtration rate values in those with or without these risk factors were not significantly different. For an ECD with a B2MG level of <7.18 and no history of RRT, kidney transplantation can be undertaken without considering the possibility of kidney discard.

Direct T-cell Inhibition and Agents Targeting T-cell Migration and Chemotaxis

Lymphocyte depletion and blockade of T-cell activation and trafficking serve as therapeutic strategies for an enlarging number of immune-mediated diseases and malignancies. This review summarizes the infection risks associated to monoclonal antibodies that bind to the α chain of the interleukin-2 receptor, the cell surface glycoprotein CD52, and members of α4- and β2-integrin families acting as cell-adhesion molecules. An outline of the mechanisms of action, approved indications and off-label uses, expected impact on the host immune response, and available clinical evidence is provided for each of these agents.

Rabbit anti-thymocyte globulin (rATG) versus IL-2 receptor antagonist induction therapies in tacrolimus-based immunosuppression era: a meta-analysis

BACKGROUND

The aim of this meta-analysis is to explore the effect of IL-2RA vs rATG on the rate of acute rejection, post-transplant infections, and graft as well as patient's survival in standard- and high-risk renal transplant patients receiving tacrolimus-based maintenance immunotherapy.

METHODS

Random effects model was the method used for identifying risk difference. Confidence interval including the value 1 was used as evidence for statistically significant risk difference. Heterogeneity was assessed using Der Simonian analysis. Heterogeneity was evident at the level of P value < 0.1 RESULTS: The random effects model showed no significant differences in both acute rejection rates between IL-2RA and rATG induction therapies with relative risk of 1.24 graft survival with relative risk 0.90. Patient survival also did not demonstrate any significant difference with a relative risk of 1.19. Random effects for CMV infection showed a lesser tendency for CMV infection in IL-2RA group compared to ATG group the with a relative risk of 0.73.In subgroup analysis, the random effects model for acute rejection rates in high-risk transplants showed a higher risk of acute rejection in the IL-2RA group compared to rATG (relative risk equals 1.55) In standard-risk transplants, there were no significant differences between both groups with relative risk equals 1.02 CONCLUSIONS: This meta-analysis revealed no significant difference in patient and graft survival when using IL-2RA vs rATG with the tacrolimus-based maintenance immunosuppression era. However, subgroup analysis showed less incidence of rejection in high-risk renal transplant recipient's population using rATG compared to IL-2RA.