Induction antibody therapy in renal transplantation using early steroid withdrawal: long-term results comparing anti-IL2 receptor and anti-thymocyte globulin

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.

Evaluating anti-thymocyte globulin induction doses for better allograft and patient survival in Asian kidney transplant recipients

Anti-thymocyte globulin (ATG) is currently the most widely prescribed induction regimen for preventing acute rejection after solid organ transplantation. However, the optimal dose of ATG induction regimen in Asian kidney recipients is unclear. Using the Korean Organ Transplantation Registry, we performed a retrospective cohort study of 4579 adult patients who received renal transplantation in South Korea and divided them into three groups according to the induction regimen: basiliximab group (n = 3655), low-dose ATG group (≤ 4.5 mg/kg; n = 467), and high-dose ATG group (> 4.5 mg/kg; n = 457). We applied the Toolkit for Weighting and Analysis of Nonequivalent Groups (TWANG) package to generate high-quality propensity score weights for intergroup comparisons. During four-year follow-ups, the high-dose ATG group had the highest biopsy-proven acute rejection rate (basiliximab 20.8% vs. low-dose ATG 22.4% vs. high-dose ATG 25.6%; P < 0.001). However, the rates of overall graft failure (4.0% vs. 5.0% vs. 2.6%; P < 0.001) and mortality (1.7% vs. 2.8% vs. 1.0%; P < 0.001) were the lowest in the high-dose ATG group. Our results show that high-dose ATG induction (> 4.5 mg/kg) was superior to basiliximab and low-dose ATG induction in terms of graft and patient survival in Asian patients undergoing kidney transplant.

A prospective, randomized, non-blinded, non-inferiority pilot study to assess the effect of low-dose anti-thymocyte globulin with low-dose tacrolimus and early steroid withdrawal on clinical outcomes in non-sensitized living-donor kidney recipients

BACKGROUND

The optimal dose of anti-thymocyte globulin (ATG) as an induction regimen in Asian living-donor kidney recipients is unclear.

METHODS

This is a pilot study in which 36 consecutive patients undergoing living-donor kidney transplantation were randomly assigned to receive either 4.5 mg/kg (n = 19) or 6.0 mg/kg (n = 17) of ATG; all patients had corticosteroid withdrawal within 7 days. The primary end point was a composite of biopsy-proven acute rejection, de novo donor-specific antibody formation, and graft failure.

RESULTS

At 12 months post-transplant, biopsy-proven acute rejection was more common in the ATG4.5 group (21.1%) than in the ATG6.0 group (0%)(P = .048). Importantly, the rate of the composite end point was significantly higher in the ATG4.5 group (36.8% vs 0%)(P = .006). There were significant differences in neither the renal function nor adverse events between the two groups. One case of death-censored graft failure occurred in the ATG4.5 group and no mortality was observed overall. Compared with pre-transplantation, T cells, natural killer (NK) cells, and natural killer T (NKT) cells were significantly decreased in the first week post-transplantation except for B cells. Although T and NKT cells in both groups and NK cells in the ATG4.5 group had recovered to the pre-transplant levels, NK cells in the ATG6.0 group remained suppressed until six months post-transplant.

CONCLUSIONS

Compared with ATG 6.0 mg/kg, ATG 4.5 mg/kg with early corticosteroid withdrawal and low dose maintenance regimen was associated with higher rates of acute rejection in non-sensitized Asian living-donor kidney recipients.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02447822.

Recommendations for living donor kidney transplantation

This Guide for Living Donor Kidney Transplantation (LDKT) has been prepared with the sponsorship of the Spanish Society of Nephrology (SEN), the Spanish Transplant Society (SET), and the Spanish National Transplant Organization (ONT). It updates evidence to offer the best chronic renal failure treatment when a potential living donor is available. The core aim of this Guide is to supply clinicians who evaluate living donors and transplant recipients with the best decision-making tools, to optimise their outcomes. Moreover, the role of living donors in the current KT context should recover the level of importance it had until recently. To this end the new forms of incompatible HLA and/or ABO donation, as well as the paired donation which is possible in several hospitals with experience in LDKT, offer additional ways to treat renal patients with an incompatible donor. Good results in terms of patient and graft survival have expanded the range of circumstances under which living renal donors are accepted. Older donors are now accepted, as are others with factors that affect the decision, such as a borderline clinical history or alterations, which when evaluated may lead to an additional number of transplantations. This Guide does not forget that LDKT may lead to risk for the donor. Pre-donation evaluation has to centre on the problems which may arise over the short or long-term, and these have to be described to the potential donor so that they are able take them into account. Experience over recent years has led to progress in risk analysis, to protect donors' health. This aspect always has to be taken into account by LDKT programmes when evaluating potential donors. Finally, this Guide has been designed to aid decision-making, with recommendations and suggestions when uncertainties arise in pre-donation studies. Its overarching aim is to ensure that informed consent is based on high quality studies and information supplied to donors and recipients, offering the strongest possible guarantees.

Macrophage-inducible C-type lectin activates B cells to promote T cell reconstitution in heart allograft recipients

Diminishing homeostatic proliferation of memory T cells is essential for improving the efficacy of lymphoablation in transplant recipients. Our previous studies in a mouse heart transplantation model established that B lymphocytes secreting proinflammatory cytokines are critical for T cell recovery after lymphoablation. The goal of the current study was to identify mediators of B cell activation following lymphoablation in allograft recipients. Transcriptome analysis revealed that macrophage-inducible C-type lectin (Mincle, Clec4e) expression is up-regulated in B cells from heart allograft recipients treated with murine anti-thymocyte globulin (mATG). Recipient Mincle deficiency diminishes B cell production of pro-inflammatory cytokines and impairs T lymphocyte reconstitution. Mixed bone marrow chimeras lacking Mincle only in B lymphocytes have similar defects in T cell recovery. Conversely, treatment with a synthetic Mincle ligand enhances T cell reconstitution after lymphoablation in non-transplanted mice. Treatment with agonistic CD40 mAb facilitates T cell reconstitution in CD4 T cell-depleted, but not in Mincle-deficient, recipients indicating that CD40 signaling induces T cell proliferation via a Mincle-dependent pathway. These findings are the first to identify an important function of B cell Mincle as a sensor of damage-associated molecular patterns released by the graft and demonstrate its role in clinically relevant settings of organ transplantation.

Transitional changes in the incidence of hip osteonecrosis among renal transplant recipients

BACKGROUND

Immunosuppressive therapy for renal allograft recipients has changed substantially since the introduction of the anti-CD25 monoclonal antibody, basiliximab. We hypothesized that recent improvements in immunosuppressive treatment may reduce the incidence of osteonecrosis of the femoral head (ONFH). This study aimed to investigate transitional changes in the incidence of OFNH among renal transplant recipients by MRI.

METHODS

Participants comprised 110 patients who had undergone renal transplantation from 2003 to 2012, during which time basiliximab was in regular use at our institute (Recent group), and 232 patients who had undergone RT between 1986 and 2003 (Past group). We compared ONFH incidence between the two groups and evaluated risk factors for ONFH, including immunosuppressants (calcineurin inhibitors, basiliximab, and/or steroids) and postoperative renal function.

RESULTS

Incidence of ONFH was lower in the Recent group (0%) than in the Past group (3.4%; p = 0.043). In the Recent group, age was greater, ABO/human leukocyte antigen incompatibility was worse, while steroid dose was decreased and post-transplant renal function was improved. Cumulative methylprednisolone dose at postoperative week 2 and delayed graft function were identified as risk factors for ONFH.

CONCLUSION

Risk of ONFH after renal transplantation has fallen with the advent of regular use of basiliximab, although this agent does not appear to be a factor directly associated with the incidence of ONFH.

STUDY DESIGN

Clinical prognostic study (Level III case control study).

Incidence of osteonecrosis and insufficiency fracture of the hip and knee joints based on MRI in 300 renal transplant patients

INTRODUCTION

The purpose of this study was to investigate the incidence of necrosis and insufficiency fracture of the hip and knee using magnetic resonance imaging (MRI) in renal transplant patients.

METHODS

We examined 300 consecutive renal transplant patients using MRI of the hips and knees (T1-weighted coronal MRI) preoperatively and at 3 and 6 months postoperatively. Oblique axial-plane T1-weighted MRI and short-tau inversion-recovery T2-weighted MRI were performed parallel to the femoral neck when distinguishing the osteonecrosis of the femoral head (ONFH) from subchondral insufficiency fracture (SIF) of the femoral head was difficult.

RESULTS

ONFH was observed in 3 hips (3 cases, 1.0%). Osteonecrosis of the knee was observed in 2 knees (1 case, 0.3%). SIF of the femoral head was observed in 5 hips (3 cases, 1.0%). Bilateral simultaneous onset of SIF of the femoral head was observed in 2 cases (0.7%). Insufficiency fracture of the knee was observed in 2 knees (1 case, 0.3%).

CONCLUSIONS

When it was difficult to distinguish ONFH from SIF of the femoral head, oblique axial-plane T1-weighted MRI and the short-tau inversion-recovery T2-weighted MRI parallel to the femoral neck were useful to establish the correct diagnosis.

Interleukin-27 promotes CD8+ T cell reconstitution following antibody-mediated lymphoablation

Antibody-mediated lymphoablation is used in solid organ and stem cell transplantation and autoimmunity. Using murine anti-thymocyte globulin (mATG) in a mouse model of heart transplantation, we previously reported that the homeostatic recovery of CD8+ T cells requires help from depletion-resistant memory CD4+ T cells delivered through CD40-expressing B cells. This study investigated the mechanisms by which B cells mediate CD8+ T cell proliferation in lymphopenic hosts. While CD8+ T cell recovery required MHC class I expression in the host, the reconstitution occurred independently of MHC class I, MHC class II, or CD80/CD86 expression on B cells. mATG lymphoablation upregulated the B cell expression of several cytokine genes, including IL-15 and IL-27, in a CD4-dependent manner. Neither treatment with anti-CD122 mAb nor the use of IL-15Rα-/- recipients altered CD8+ T cell recovery after mATG treatment, indicating that IL-15 may be dispensable for T cell proliferation in our model. Instead, IL-27 neutralization or the use of IL-27Rα-/- CD8+ T cells inhibited CD8+ T cell proliferation and altered the phenotype and cytokine profile of reconstituted CD8+ T cells. Our findings uncover what we believe is a novel role of IL-27 in lymphopenia-induced CD8+ T cell proliferation and suggest that targeting B cell-derived cytokines may increase the efficacy of lymphoablation and improve transplant outcomes.

Rapid Discontinuation of Prednisone in Kidney Transplant Recipients: 15-Year Outcomes From the University of Minnesota

BACKGROUND

Short- and intermediate-term results have been reported after rapid discontinuation of prednisone (RDP) in kidney transplant recipients. Yet there has been residual concern about late graft failure in the absence of maintenance prednisone.

METHODS

From October 1, 1999, through June 1, 2015, we performed a total of 1553 adult first and second kidney transplants-1021 with a living donor, 532 with a deceased donor-under our RDP protocol. We analyzed the 15-year actuarial overall patient survival (PS), graft survival (GS), death-censored GS (DCGS), and acute rejection-free survival (ARFS) rates for RDP compared with historical controls on maintenance prednisone.

RESULTS

For living donor recipients, the actuarial 15-year PS rates were similar between groups. But RDP was associated with increased GS (P = 0.02) and DCGS (P = 0.01). For deceased donor recipients, RDP was associated with significantly better PS (P < 0.01), GS (P < 0.01) and DCGS (P < 0.01). There was no difference between groups in the rate of acute or chronic rejection, or in the mean estimated glomerular filtration rate at 15 years. However, RDP-treated recipients had significantly lower rates of avascular necrosis, cytomegalovirus, cataracts, new-onset diabetes after transplant, and cardiac complications. Importantly, for recipients with GS longer than 5 years, there was no difference between groups in subsequent actuarial PS, GS, and DCGS.

CONCLUSIONS

In summary, at 15 years postkidney transplant, RDP did not lead to decreased in PS or GS, or an increase in graft dysfunction but as associated with reduced complication rates.

Effect of interleukin-2 receptor antagonists on new-onset diabetes after liver transplantation: A retrospective cohort study

BACKGROUND

The aim of the present retrospective observational study was to examine the effect of interleukin-2 receptor antagonists (IL-2Ra) on new-onset diabetes after transplantation (NODAT) in liver transplant recipients.

METHODS

Pre- and postoperative clinical data of 781 patients undergoing liver transplantation between April 2001 and December 2014 at Zhongshan Hospital, Fudan University, were analyzed. Patients were divided into two groups depending on the use of IL-2Ra (IL-2Ra and non-IL-2Ra). The cumulative incidence of NODAT was compared between the IL-2Ra and non-IL-2Ra groups and the effect of IL-2Ra on the incidence of NODAT in liver transplant recipients was evaluated.

RESULTS

Of the 781 patients in the study, 451 received IL-2Ra. During follow-up, 138 (41.8%) and 137 (30.4%) patients in the non-IL-2Ra and IL-2Ra groups, respectively, developed NODAT (P = 0.001). The cumulative incidence of NODAT at 1, 3, 5, and 8 years after transplantation in the IL-2Ra group was 30%, 38%, 45%, and 54%, respectively; these values were substantially lower than corresponding values for the non-IL-2Ra group (P < 0.05). Cox regression analyses showed that IL-2Ra was a protective factor against NODAT development (odds ratio 0.685; 95% confidence interval 0.473-0.991; P = 0.044). This was independent of age, sex, donor type, hepatitis virus infection, body mass index, history of hypertension, preoperative liver function, preoperative fasting plasma glucose, total cholesterol, and total triglyceride levels, severity of liver cirrhosis, acute rejection, initial immunosuppressant regimen type, and postoperative immunosuppressant levels.

CONCLUSION

In conclusion, IL-2Ra reduces the risk of NODAT in liver transplant recipients.

Induction Immunosuppressive Therapy Use in Deceased Donor Kidney Transplantation: 11-Year Experience in Veracruz, Mexico

BACKGROUND

Induction therapy reduces the frequency of acute rejection and delayed graft function in renal transplantation. Basiliximab and Thymoglobulin are most commonly used agents for induction.

METHODS

A retrospective study of two transplant centers in Veracruz, Mexico compared induction therapy in deceased donor renal transplantation from 2003 to 2014. Efficacy and safety outcomes evaluated were primary graft nonfunction, delayed graft function, acute rejection episodes and hospitalizations during first year, and patient and graft survival. P < .05 was considered statistically significant.

RESULTS

Seventy deceased kidney donors (40 male) were studied. Mean donor age was 32.9 ± 14.3 years, mean donor BMI 25.6 ± 4.3 kg/m(2), and mean donor creatinine 1.13 ± 0.58 mg/dL. Main cause of death was trauma (62.9%). In total, 125 kidney transplantations were performed, with female predominance (53.6%) and mean age 33.8 ± 11.8 years. Of these, 66.4% used basiliximab and 33.6% Thymoglobulin. Thymoglobulin patients were significantly older, with lower weight and BMI, and were on dialysis longer than basiliximab patients. DGF was present in 19.3% of basiliximab patients vs 16.7% in Thymoglobulin patients, acute rejection occurred in 16.9% of basiliximab patients vs 19% Thymoglobulin patients. A total of 33.7% basiliximab patients were hospitalized during the first year vs 47.6% Thymoglobulin-induced patients (P > .05). Mean graft survival was 84.2 ± 5.3 months (73.8-94.7) basiliximab vs 32.4 ± 28.7 months (28.7-36.1) Thymoglobulin, Kaplan-Meier survival did not show statistically significant differences between groups (P = .276; CI 95%).

CONCLUSION

Similar transplant outcomes were obtained using basiliximab or Thymoglobulin induction in our population.

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.

Polyclonal versus monoclonal induction therapy in a calcineurin inhibitor-free immunosuppressive therapy in renal transplantation: a comparison of efficacy and costs

BACKGROUND

Induction therapy in renal transplantation reduces the incidence of acute rejection (AR) in expanded criteria donation (ECD) and donation after cardiac death (DCD). We compared the efficacy of Thymoglobulin (Sanofi-Aventis, Spain), ATG Fresenius (ATG-Fresenius, Spain), and Simulect (Novartis Farm, Spain) in a calcineurin-free protocol in ECD and DCD renal transplantation by evaluating patient survival, graft survival, and AR at 1 year and overall costs.

METHODS

An observational retrospective study was performed using our database of 289 consecutive cadaveric ECD renal transplant recipients (n = 178) and DCD recipients (n = 111) from April 1999 to December 2011. Induction therapy consisted of Simulect, Thymoglobulin, and ATG Fresenius. Calcineurin-inhibitor (CNI)-free maintenance therapy consisted of mycophenolate mofetil or sodium and steroids.

RESULTS

There were no differences in the patients' demographic characteristics or patient and graft survival. One-year AR rates were equivalent (ECD: 10%, 19.1%, 17.7% versus DCD: 14.3%, 7.1%, 16.7%). Leukopenia and thrombopenia were significantly more frequent in the ECD group treated with polyclonal induction. The average total cost of transplantation was higher in the ECD group but there were no significant differences in the average total cost between ECD and DCD: 39,970.31 ± 7,732€ versus 35,058.34 ± 6,801€ (P = NS).

CONCLUSION

Our study shows the same efficacy with polyclonal and monoclonal antibody induction and a CNI-free treatment regimen in ECD and DCD renal transplantation with no differences in overall costs at 1 year after transplantation.

New directions for rabbit antithymocyte globulin (Thymoglobulin(®)) in solid organ transplants, stem cell transplants and autoimmunity

In the 30 years since the rabbit antithymocyte globulin (rATG) Thymoglobulin^® was first licensed, its use in solid organ transplantation and hematology has expanded progressively. Although the evidence base is incomplete, specific roles for rATG in organ transplant recipients using contemporary dosing strategies are now relatively well-identified. The addition of rATG induction to a standard triple or dual regimen reduces acute cellular rejection, and possibly humoral rejection. It is an appropriate first choice in patients with moderate or high immunological risk, and may be used in low-risk patients receiving a calcineurin inhibitor (CNI)-sparing regimen from time of transplant, or if early steroid withdrawal is planned. Kidney transplant patients at risk of delayed graft function may also benefit from the use of rATG to facilitate delayed CNI introduction. In hematopoietic stem cell transplantation, rATG has become an important component of conventional myeloablative conditioning regimens, following demonstration of reduced acute and chronic graft-versus-host disease. More recently, a role for rATG has also been established in reduced-intensity conditioning regimens. In autoimmunity, rATG contributes to the treatment of severe aplastic anemia, and has been incorporated in autograft projects for the management of conditions such as multiple sclerosis, Crohn’s disease, and systemic sclerosis. Finally, research is underway for the induction of tolerance exploiting the ability of rATG to induce immunosuppresive cells such as regulatory T-cells. Despite its long history, rATG remains a key component of the immunosuppressive armamentarium, and its complex immunological properties indicate that its use will expand to a wider range of disease conditions in the future.

An in-progress, open-label, multi-centre study (SAILOR) evaluating whether a steroid-free immunosuppressive protocol, based on ATG induction and a low tacrolimus dose, reduces the incidence of new onset diabetes after transplantation

Background

Corticosteroids and calcineurin inhibitors (CNIs) are included in renal transplantation immunosuppressive protocols around the world. Well-known side effects are associated with the use of these drugs, including new onset of diabetes after transplantation (NODAT). Long-term patient survival rates are lower among patients with NODAT. The optimal immunosuppressive protocol would therefore include not using corticosteroids and minimization of CNI use.

Methods/Design

This is a prospective, multi-centre, controlled, randomized, parallel group, open-label study involving kidney transplant patients. The study compares a steroid-free immunosuppressive protocol (study arm A), which is based on low-dose tacrolimus and mycophenolate mofetil (MMF) maintenance therapy together with antithymocyte globulin (ATG) induction, with the conventional immunosuppressive protocol (study arm B), being based on low-dose tacrolimus, MMF and steroids together with interleukin-2 receptor (IL2-R) induction. The study is designed to include most normal-risk patients. It will exclude patients seen as at a high risk of rejection. The primary objective of the study is to assess the cumulative incidence of NODAT in the two study arms 12 months after transplantation using the American Diabetes Association type 2 diabetes diagnostic criteria. The composite measure of freedom from acute rejection, graft survival and patient survival will be evaluated. Renal function and chronic changes in the transplanted kidney will be assessed.

Discussion

If this study confirms conceptual expectations, namely decreased incidence of NODAT, the steroid-free study protocol could be used with all patients. The regimen could be especially beneficial for patients at a high risk of diabetes mellitus.

Trial registration

Trial registration: EudraCT 2012-000451-13.

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.