Low-Dose Rabbit Antithymocyte Globulin Versus Basiliximab Induction Therapy in Low-Risk Renal Transplant Recipients: 8-Year Follow-Up

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.

Selection of More Vulnerable Patients for Cytomegalovirus Infection in Renal Transplant Recipients With Antithymocyte Globulin Induction Therapy: An Analysis of Risk Factors and Cell-Mediated Immunity

BACKGROUND

Cytomegalovirus (CMV) infection is an important complication after kidney transplantation (KT). Antithymocyte globulin (ATG) increases the risk for CMV infection, and universal prophylaxis is recommended during the first 3 to 6 months after ATG induction in CMV-seropositive recipients. However, following this recommendation is not easy because the cost is high. The aim of this study was to determine who, among high-risk KT recipients, are more vulnerable to CMV infections.

METHODS

We retrospectively analyzed the medical records of patients who underwent KT with ATG induction therapy at a single institute from April 2014 to June 2019. We assessed pretransplant recipient characteristics to determine the CMV infection risk factors. Cell-mediated immunity was evaluated with a lymphocyte subset test before transplantation and at the time of discharge. We included 227 patients in the study.

RESULTS

CMV-DNAemia was associated with donor type (deceased donor), the duration of renal replacement therapy, and the ATG dose. Multivariable analysis revealed that donor type is the primary risk factor for CMV-DNAemia. We also found that CD4+ cell counts were significantly lower in CMV-DNAemia recipients at the time of discharge.

CONCLUSION

The risk for CMV infection in CMV-seropositive KT recipients with ATG induction therapy increases when a graft is received from a deceased donor with renal impairment and when insufficient CD4+ cells are present during recovery.

Low-Dose Antithymocyte Globulin Has No Disadvantages to Standard Higher Dose in Pediatric Kidney Transplant Recipients: Report From the Pediatric Nephrology Research Consortium

INTRODUCTION

Rabbit antithymocyte globulin (rATG) dosing strategies for induction in pediatric kidney transplantation vary between centers. It is not known whether a lower rATG induction dose provides safe and effective immunosuppression compared with a "standard" higher dose.

METHODS

We performed a retrospective multicenter study of all isolated first-time kidney transplant recipients <21 years old who received rATG induction between 1 January 2010 and 31 December 2014 at 9 pediatric centers. An a priori cutoff of a 4.5-mg/kg cumulative rATG dose was used to identify low (≤ 4.5 mg/kg) and standard (> 4.5 mg/kg) exposure groups. Outcomes examined included 12 months posttransplant graft function (estimated glomerular filtration rate [eGFR]); the occurrence of acute rejection, donor-specific antibody (DSA), neutropenia, and viral infection (cytomegalovirus [CMV], Epstein-Barr virus [EBV], and BK virus); and 24-month outcomes of posttransplant lymphoproliferative disorder (PTLD) occurrence and patient and graft survival.

RESULTS

Two hundred thirty-five patients were included. Baseline features of the low and standard rATG dose groups were similar. By 12 months, the rATG dose group had no significant impact on the occurrence of neutropenia, positive DSA, or viral polymerase chain reaction (PCR). Graft function was similar. Acute rejection rates were similar at 17% (low dose) versus 19% (standard dose) (P = 0.13). By 24 months, graft survival (96.4% vs. 94.6%) and patient survival (100% vs. 99.3%) were similar between the low- and standard-dose groups (P = 0.54 and 0.46), whereas the occurrence of PTLD trended higher in the standard-dose group (0% vs. 2.6%, P = 0.07).

CONCLUSION

A low rATG induction dose ≤ 4.5 mg/kg provided safe and effective outcomes in this multicenter low immunologic risk pediatric cohort. Prospective studies are warranted to define the optimal rATG induction dose in pediatric kidney transplantation.

Reassessing Rabbit Antithymocyte Globulin Induction in Kidney Transplantation (RETHINK): An Analysis of the North American Pediatric Renal Trials and Collaborative Studies (NAPRTCS) Registry

Supplemental Digital Content is available in the text.

Background.

There is no consensus on rabbit antithymocyte globulin (rATG) dose used for induction immunosuppression in pediatric kidney transplants. We aimed to identify whether a lower rATG dose provides safe and effective immunosuppression compared with a higher dose.

Methods.

We retrospectively analyzed all first-time kidney transplant recipients (aged <21 y) in the North American Pediatric Renal Trials and Collaborative Studies registry since 1998 on mycophenolate mofetil– and tacrolimus-based immunosuppression with rATG induction. An a priori cutoff of 7.5 mg/kg cumulative rATG dose was used to identify low (<7.5 mg/kg) and high (≥7.5 mg/kg) exposure groups. Primary outcome was time to first-acute rejection episode. Secondary outcomes included graft function, patient survival, hospitalizations due to infections, and time to first-posttransplant lymphoproliferative disorder episode.

Results.

Four hundred fifty-five patients met inclusion criteria (59% male, 49% whites, 26% blacks, 38% living donor source). Median cumulative rATG dose was 6.8 mg/kg with a median of 5 doses and a median 1.5 mg/kg/dose introduced at a median of postoperative 0 days. Sixty-four percent received <7.5 mg/kg total rATG. There was no difference in age at transplant, gender, race, end-stage renal disease causes, or HLA mismatch among groups. Time to first-acute rejection was similar (P = 0.07). There was no significant difference in graft or patient survival or time to posttransplant lymphoproliferative disorder. Hospitalization for infection rates was similar.

Conclusions.

These data demonstrate a wide variation in cumulative rATG induction dose. A smaller rATG dose <7.5 mg/kg may provide effective and safe immunosuppression compared with a higher dose.

Outcome Comparison between Low-Dose Rabbit Anti-Thymocyte Globulin and Basiliximab in Low-Risk Living Donor Kidney Transplantation

The objective of this study was to compare outcomes between basiliximab and low-dose r-ATG in living donor kidney transplantation recipients with low immunological risk. Patients in the low-dose r-ATG group received 1.5 mg/kg of r-ATG for 3 days (total 4.5 mg/kg). Graft survival, patient survival, acute rejection, de novo donor specific antibody (DSA), estimated glomerular filtration rate (e-GFR) changes, and infection status were compared. Among 268 patients, 37 received r-ATG, and 231 received basiliximab. There was no noticeable difference in the graft failure rate (r-ATG vs. basiliximab: 2.7% vs. 4.8%) or rejection (51.4% vs. 45.9%). de novo DSA was more frequent in the r-ATG group (11.4% vs. 2.4%, p = 0.017). e-GFR changes did not differ noticeably between groups. Although most infections showed no noticeable differences between groups, more patients in the r-ATG group had cytomegalovirus (CMV) antigenemia and serum polyomavirus (BK virus) (73.0% vs. 51.9%, p = 0.032 in CMV; 37.8% vs. 15.6%, p = 0.002 in BK), which did not aggravate graft failure. Living donor kidney transplantation patients who received low-dose r-ATG and patients who received basiliximab showed comparable outcomes in terms of graft survival, function, and overall infections. Although CMV antigenemia, BK viremia were more frequent in the r-ATG group, those factors didn’t change the graft outcomes.

Low-dose Thymoglobulin vs Basiliximab Induction Therapy in Low-Risk Living Related Kidney Transplant Recipients: A Prospective Randomized Trial

CONTEXT

Thymoglobulin is used effectively as induction agent in kidney transplantation but the optimal dose is not well established.

OBJECTIVE

Demonstrate that low-dose thymoglobulin (3 mg/kg) has similar efficacy and safety compared to basiliximab induction in low-risk kidney transplantation under standard maintenance immunosuppression DESIGN, SETTING, PARTICIPANTS: Prospective randomized study in kidney transplant patients (12/2016-05/2018).

INCLUSION CRITERIA

Recipients > 18 years, first living donor transplant.

EXCLUSION CRITERIA

Second and multiorgan transplant, ABO incompatibility, positive cross-match, panel reactive antibodies (PRA) > 30%, positive donor-specific antibody, human immunodeficiency virus, hepatitis B surface antigen, hepatitis C virus positive, white blood cells < 2000 cells/mm³, platelets < 75,000 cells/mm³ and malignancy.

INTERVENTION

Group A: basiliximab (20 mg D0 and D4). Group B: thymoglobulin (3 mg/kg total). Maintenance immunosuppression: tacrolimus, mycophenolate mofetil, and steroids.

MAIN OUTCOME MEASURES

Biopsy-proven acute rejection (BPAR), delayed graft function, slow graft function, leukopenia, infections, adverse events, graft loss, estimated glomerular filtration rate, and death within 12 months.

RESULTS

100 patients (basiliximab, n = 53) (thymoglobulin, n = 47) were included. Donor and recipient characteristics were similar except for longer dialysis (basiliximab), PRA class I (1.2% basiliximab, 4.5% thymoglobulin), HLA match (basiliximab 2.8, thymoglobulin 2.2), and cytomegalovirus status. BPAR rate was basiliximab 3.8% and thymoglobulin 6.4% (P = ns). Delayed graft function (basiliximab 3.8%; thymoglobulin 4.3%), slow graft function, and 12-month leukopenia (basiliximab 11.3%, thymoglobulin 21.3%) were similar between groups (P = ns). There was no difference in infections and adverse events between groups. Patient and graft survival were as follows: basiliximab 98.1% and 92.5%, thymoglobulin 100% and 93.6% (P = ns).

CONCLUSION

Low-dose thymoglobulin induction (3 mg/kg) can be used effectively and safely in low-risk kidney transplantation with good results during the first year post-transplant.

Effects of immunotherapy induction on outcome and graft survival of kidney-transplanted patients with different immunological risk of rejection

BACKGROUND

In kidney transplantation, immunotherapy with thymoglobulin (rATG) has been used to down-regulate the patient immune system. rATG is a powerful immunobiologic drug used to deplete lymphocytes to prevent early acute rejection. The aim of this research was to evaluate the effects of immunotherapy by rATG on graft suvival during a 9-year period in kidney-transplanted patients with different immunological profiles.

METHODS

A sample of 469 patients were allocated into four groups (G) based on immunological risk of rejection: G1, low risk, not sensitized recipients, solid-phase immunoassay with single antigen beads (SPI-SAB) < 10%; G2, medium risk I, sensitized recipients, SPI-SAB ≥ 10 < 50%; G3, medium risk II sensitized (SPI-SAB ≥50%); and G4, high risk, sensitized recipients, SPI-SAB- donor-specific antibody positive (DSA+). Only patients from G3 and G4 received immunotherapy.

RESULTS

Of 255 patients who received a kidney from a living donor (LD), 42 (16.47%) from all groups (G) had T-cell-mediated rejection (TCMR) and four (G1) lost their grafts, 8 (3.14%) had antibody-mediated rejection (AMR), and two lost their graft in G1 and G4. Of 214 patients who received a kidney from deceased donors (DD), 37 (17.29%) had TCMR with one lost graft in G1. AMR was shown in 13 (6.07%) patients, with three losses observed in G2. Statistical differences between the groups in the 9-year graft survival rate were found only in the comparison of G1 versus G2 (P = 0.005) and G2 versus G4 (P = 0.047) for DD. For LD, no statistical differences were found.

CONCLUSION

This clinical retrospective study shows that immunotherapy induction was associated with improvement of outcomes, graft function, and survival in patients treated with immunotherapy in comparison with patients who did not received induction therapy. These findings strongly suggest that immunotherapy should be used for all patients transplanted with kidneys from deceased donors.

Management of Immunosuppression in Liver Transplantation

Liver transplantation outcomes have significantly improved over the past few decades owing largely to the introduction of effective immunosuppression medications. Further comprehension of the unique immune microenvironment of the liver has led to the development of newer molecular targeted therapeutics. Understanding the mechanism of action and adverse effect profiles of these medications is crucial for appropriate management of posttransplant patients. In this review, the author describes the immunologic response elicited by liver transplantation, chronicles the various immunosuppressant drug classes, discusses the evidence behind their use, and evaluates the management of special subpopulations of posttransplantation patients.

Predictive Factors of Acute Rejection in Low Immunologic Risk Kidney Transplant Recipients Receiving Basiliximab

INTRODUCTION

The optimal immunosuppressive induction therapy in kidney transplant recipients with low immunologic risk of acute rejection (AR) is still controversial. The use of basiliximab (BSX) has led to a significant decrease of AR with a low side effect profile.

OBJECTIVE

This study sought to evaluate predictive risk factors for AR in low immunologic risk patients subjected to immunosuppressive induction therapy with BSX.

METHODS

We reviewed all low immunologic risk patients (panel reactive antibody [PRA] level <50%, who had undergone a first deceased-donor transplant) subjected to immunosuppressive induction therapy with BSX, calcineurin inhibitor, mycophenolate mofetil, and prednisolone (n = 346). AR was defined as any rejection occurring until 12 months posttransplantation. Predictive risk factors for AR were evaluated by logistic regression and, to find the best cut-off of PRA related to a higher incidence of AR, receiver-operator characteristic (ROC) curve analysis was performed.

RESULTS

The rate of AR was 7.8%. Multivariate logistic regression analysis identified age at the time of transplantation (P = .040) and PRA level (P = .001) as independent risk factors for AR. ROC curve analysis confirmed that PRA >10% was related to an increased incidence of AR (19.2% vs 6.0%, P = .005).

CONCLUSIONS

A higher incidence of AR was observed in low immunologic risk kidney transplant patients with a PRA level >10%. These data support the use of more intensive immunosuppressive induction therapy in patients with low immunologic risk and a PRA level >10%.

Impact of Rabbit Antithymocyte Globulin Dose on Long-term Outcomes in Heart Transplant Patients

BACKGROUND

Optimal dosing strategies have not been established for rabbit antithymocyte globulin (rATG) after heart transplantation, and there is currently wide variability in rATG regimens with respect to both dose and duration.

METHODS

In a retrospective, single-center analysis, 523 patients undergoing heart transplantation during 1996 to 2009 were stratified by cumulative rATG dose: less than 4.5 mg/kg (group A), 4.5 to 7.5 mg/kg (group B) or greater than 7.5 mg/kg (group C).

RESULTS

Survival at 1 year after transplantation was 80% in group A, 90% in group B, and 88% in group C (P = 0.062). Incidence of acute rejection per 1000 patient-years was significantly higher in group A (hazards ratio [HR], 54.8; 95% confidence interval [95% CI], 33.9-83.8) compared to groups B (19.6; 95% CI, 11.4-31.4) and C (23.6; 95% CI, 17.5-31.3). Incidence of severe infection 10 years after transplantation was higher in group C (45%) than groups A (37%) or B (23%) (P < 0.001); cytomegalovirus infection rates were 35%, 20% and 23%, respectively (P = 0.009). Multivariable Cox regression showed an HR of 0.51 (95% CI, 0.25-1.02) for acute rejection with group B versus group A, and 0.54 (95% CI, 0.33-0.88; P = 0.013) for severe infection. The rate of malignancy per 1000 patient-years was higher in groups B (13.85) and C (14.95) than group A (7.83).

CONCLUSIONS

These retrospective data suggest that a cumulative rATG dose of 4.5 to 7.5 mg/kg may offer a better risk-benefit ratio than lower or higher doses, with acceptable rates of infection and posttransplant malignancy. Prospective trials are needed.

Thymoglobulin Induction Therapy in Deceased Donor Kidney Transplantation: Single-Center Experience in Mexico

BACKGROUND

Induction therapy is used to reduce the incidence of graft rejection and delayed graft function. Thymoglobulin is the most used inductor agent in deceased donor kidney transplantation due to its lower rejection and delayed graft function rates.

METHODS

Retrospective study of patients who underwent deceased donor kidney transplantation from 2011 to 2014. Efficacy and safety outcomes evaluated were primary graft nonfunction, delayed graft function, acute rejection episodes, the lowest leukocyte count during the induction, adverse effects, eGFR, and patient and graft survival. P < .05 was considered statistically significant.

RESULTS

A total of 42 patients were registered. Of these, 51.7% were female, with a mean age of 36.4 ± 11.1 years. Mean dialysis time was 112.4 ± 365 months. Mean donor age was 33.7 ± 13.1 years. Of the registered patients, 14.3% were extended criteria donors and 23.8% high-risk. Mean thymoglobulin dose was 4.4 ± 0.8 mg/kg. Primary graft nonfunction was 2.4%. Nineteen percent presented with delayed graft function and 19% with acute rejection. Mean lowest leukocyte count was of 4.6 ± 1.5 × 10(3) cells/mm(3). Mean hospital stay was 11.3 ± 6.3 days. Adverse effects were seen in 59.5% of registered patients, whereas graft survival 1 year and 3 years after transplantation was 85.3% and 56.9%, respectively. Patient survival 1 year and 3 years after transplantation was 85.3% and 53.8%, respectively. Patients who received a higher dose (>4.4 mg/kg) had a shorter hospital stay (9.4 ± 4.6 and 8.1 ± 2.3) than those who received lower dose (13.6 ± 7.9 and 12.8 ± 7.4; P < .05).

CONCLUSION

Thymoglobulin induction at doses near 5 mg/kg in deceased donor kidney transplant is efficient and secure at our center.

Induction by anti-thymocyte globulins in kidney transplantation: a review of the literature and current usage

Context: Preventing acute rejection (AR) after kidney transplantation is of utmost importance because an AR can have a negative impact on long-term allograft survival.

Evidence Acquisition: Directory of Open Access Journals (DOAJ), Google Scholar, PubMed, EBSCO, and Web of Science have been searched.

Results: At the moment this can be done by using rabbit anti-thymocyte globulins (rATGs) as an induction therapy. However, because rATGs are associated with some deleterious side-effects, such as the opportunistic infections cytomegalovirus (CMV) and de novo post-transplant cancer, it is very important they are used optimally, i.e., at minimal doses that avoid many side-effects but still retain optimal treatment efficacy. Recent data show that the risk of CMV infection can be minimized using tacrolimus plus everolimus, and not tacrolimus plus mycophenolic acid, as the maintenance immunosuppression. The use of rATG is particularly valuable in; (a) sensitized patients; (b) in recipients from an expanded-criteria donor, thus enabling the introduction of calcineurin inhibitors at reduced doses; and (c) for patients where steroid avoidance is contemplated. However, we also need to consider that rATG may increase the risk of de novo cancer, even though recent data indicate this is unlikely and that any risk can be reduced by using mammalian target of rapamycin (mTOR) inhibitors instead of mycophenolic acid combined with low-dose calcineurin inhibitors.

Conclusions: Even though rATGs do not improve long-term kidney-allograft survival, they may help reduce calcineurin-inhibitor dosage during the early post-transplant period and minimize the risk of AR.

Outcome and cost analysis of induction immunosuppression with IL2Mab or ATG in DCD kidney transplants

BACKGROUND

Kidney transplantation from DCD now represents a significant part of the overall transplant activity in the UK. Outcome of different induction immunosuppression regimes and related cost benefit analysis has been reported by very few studies.This is a single centre study on frequency-matched patients who received a DCD kidney transplant between August 2007 and August 2009.

METHODS

Data on 45 patients divided in 2 groups were collected prospectively and analyzed retrospectively. Group A (24 patients) received IL2Mab and Group B (21 patients) ATG as induction immunosuppression. Patient and graft survival were similar in both groups.

RESULTS

In the ATG-induced group, there was a significant lower rate of DGF, BPAR, and infections requiring readmission.A cost analysis was performed including all immunosuppression-related costs, and it has shown remarkable savings in the ATG-induced group.

CONCLUSION

Considering that the number of DCD kidney transplants is destined to rise in the UK, we believe that ATG is a valid option to continue optimizing outcomes of DCD kidney transplant. In our experience, ATG proved to be safe, effective, and contributed to significant cost savings.

Selection of induction therapy in kidney transplantation

Currently available immunosuppressive agents can be classified into three categories: induction agents, maintenance therapy, and treatment for rejection. This review article will focus on induction immunosuppression. There are three antibodies which are used for induction therapy: the lymphocyte-depleting agents - anti-thymocyte globulin and alemtuzumab, and basiliximab which is nondepleting. Historically, immunosuppressant selection was solely based on efficacy for prevention of rejection. In the current era of transplantation, it is now common practice in the transplant community to select induction therapy on the basis of risk-benefit considerations for each patient. This article will focus on the efficacy of available induction agents and the selection of induction agent based on donor and recipient risk factors.