Anti-thymocyte globulins in kidney transplantation: focus on current indications and long-term immunological side effects

Impact of induction agents and maintenance immunosuppression on torque teno virus loads and year-one complications after kidney transplantation

Background

Torque teno virus load (TTVL) is gaining importance as a surrogate parameter to assess immunocompetence in kidney transplant recipients. Although the dynamics of TTVL have been investigated before, the impact of different induction agents and variations in immunosuppressive maintenance therapies on TTVL remain unknown.

Methods

In this retrospective study, TTVL was quantified in 537 plasma or serum samples from 134 patients transplanted between 2018 and 2021. TTVL was examined pre-transplantation and 30-, 90-, 180-, and 360-days post-transplant. To assess the influence of induction therapy on TTVL, 67 patients receiving anti-thymocyte globulin (ATG) induction were matched with 67 patients receiving an interleukin-2 receptor antagonist (IL2-RA) induction in terms of age, sex, and donor modality.

Results

Following transplantation, there was a steep increase in TTVL post-transplant for all patients with peak viral loads at 90 days post-transplant (median TTVL [IQR] 7.97×106, [4.50×105-1.12×108]) followed by subsequently declining viral loads. Compared to patients receiving IL2-RA as induction therapy, patients receiving ATG had significantly higher peak viral loads 3 months post-transplant (median TTVL [IQR] 2.82×107 [3.93×106-1.30×108] vs. median TTVL [IQR] 2.40×106 [5.73×104-2.60×107]; P<0.001). Throughout all post-transplant time points, patients receiving additional rituximab for induction along with higher tacrolimus target levels exhibited the highest TTVL.Patients whose TTVL 3-months post-transplant exceeded the currently proposed cutoff to predict infections within the first year post-transplant [6.2 log10] showed a trend towards a higher risk of being hospitalized with an infection in the following 9 months, albeit without being statistically significant (HR=1.642, P=0.07).

Conclusions

Higher TTVL reflects the greater immunosuppressive burden in immunological high-risk patients receiving intensive immunosuppression. The choice of induction agent and intensified immunosuppressive maintenance therapy notably affects TTVL at 3 months post-transplant and beyond, necessitating careful consideration when interpreting and applying TTVL cutoffs to monitor immunocompetence post-transplant.

Comparative Efficacy and Safety of Low-Dose Versus Standard-Dose Rabbit Antithymocyte Globulin Induction Strategy in Kidney Transplant Recipients: Insights From a Single-Center Experience in North India

Background Rabbit antithymocyte globulin (rATG) is frequently utilized as an induction therapy in kidney transplant recipients (KTRs). Full-dose rATG induction therapy (7-10 mg/kg) has been associated with increased morbidity. However, definitive data on the appropriate rATG dosage remains scarce. In this study, we evaluated the efficacy and tolerability of varying rATG doses in KTRs. Methodology A single-center, retrospective, observational study was conducted between 2009 and 2014 in a cohort of 208 KTRs who received rATG induction therapy. Patients included in the study had received two to three consecutive doses of rATG as part of their planned induction protocol. Participants were categorized into the following two groups based on the cumulative dosage of rATG received during induction therapy: group A received 2 or 2.5 mg/kg, while group B received ≥3 mg/kg. The five-year follow-up data were analyzed. Results A cumulative rATG dose of 2 or 2.5 mg/kg and ≥3 mg/kg was given to 122 and 86 patients, respectively. The incidence of delayed graft function (DGF), acute rejection episodes, total graft loss, death, and death-censored graft loss was 6.25%, 3.84%, 7.21%, 4.32%, and 2.88%, respectively. Two malignancies and 141 infectious complications were noted. There was no significant difference between the groups regarding DGF, total graft loss, death, death-censored graft loss, infectious complications, and incidence of acute rejection episodes. Deceased donor kidney transplantation was identified as a significant predictor of acute rejection episodes (odds ratio = 9.19, 95% confidence interval = 1.567-53.907; p = 0.014). Conclusions The dosage for rATG induction therapy for KTRs should be tailored based on immunological and other factors impacting graft survival, along with a comprehensive risk assessment for potential infectious complications. A cumulative dose of 2.0 or 2.5 mg/kg could be optimal, offering effective induction therapy in KTRs with excellent graft survival rates and potentially fewer infectious complications.

Functionalized magnetic nanoparticles remove donor-specific antibodies (DSA) from patient blood in a first ex vivo proof of principle study

The presence of donor-specific antibodies (DSA) such as antibodies directed against donor class I human leucocyte antigen (e.g., HLA-A) is a major barrier to kidney transplant success. As a proof of concept, functionalized magnetic nanoparticles have been designed to eliminate DSA from saline, blood and plasma of healthy donors and sensitized patients. Specific HLA-A1 protein was covalently bound to functionalized cobalt nanoparticles (fNP), human serum albumin (HSA) as control. fNP were added to anti-HLA class I-spiked saline, spiked volunteers' whole blood, and to whole blood and plasma of sensitized patients ex vivo. Anti-HLA-A1 antibody levels were determined with Luminex technology. Antibodies' median fluorescent intensity (MFI) was defined as the primary outcome. Furthermore, the impact of fNP treatment on blood coagulation and cellular uptake was determined. Treatment with fNP reduced MFI by 97 ± 2% and by 94 ± 4% (p < 0.001 and p = 0.001) in spiked saline and whole blood, respectively. In six known sensitized anti-HLA-A1 positive patients, a reduction of 65 ± 26% (p = 0.002) in plasma and 65 ± 33% (p = 0.012) in whole blood was achieved. No impact on coagulation was observed. A minimal number of nanoparticles was detected in peripheral mononuclear blood cells. The study demonstrates-in a first step-the feasibility of anti-HLA antibody removal using fNP. These pilot data might pave the way for a new personalized DSA removal technology in the future.

Immune modulation in transplant medicine: a comprehensive review of cell therapy applications and future directions

Balancing the immune response after solid organ transplantation (SOT) and vascularized composite allotransplantation (VCA) remains an ongoing clinical challenge. While immunosuppressants can effectively reduce acute rejection rates following transplant surgery, some patients still experience recurrent acute rejection episodes, which in turn may progress to chronic rejection. Furthermore, these immunosuppressive regimens are associated with an increased risk of malignancies and metabolic disorders. Despite significant advancements in the field, these IS related side effects persist as clinical hurdles, emphasizing the need for innovative therapeutic strategies to improve transplant survival and longevity. Cellular therapy, a novel therapeutic approach, has emerged as a potential pathway to promote immune tolerance while minimizing systemic side-effects of standard IS regiments. Various cell types, including chimeric antigen receptor T cells (CAR-T), mesenchymal stromal cells (MSCs), regulatory myeloid cells (RMCs) and regulatory T cells (Tregs), offer unique immunomodulatory properties that may help achieve improved outcomes in transplant patients. This review aims to elucidate the role of cellular therapies, particularly MSCs, T cells, Tregs, RMCs, macrophages, and dendritic cells in SOT and VCA. We explore the immunological features of each cell type, their capacity for immune regulation, and the prospective advantages and obstacles linked to their application in transplant patients. An in-depth outline of the current state of the technology may help SOT and VCA providers refine their perioperative treatment strategies while laying the foundation for further trials that investigate cellular therapeutics in transplantation surgery.

Advancing cytomegalovirus prevention in solid organ transplant recipients: The promise of cell-mediated immune assays

Cytomegalovirus (CMV) infections are a major source of morbidity and mortality in solid organ transplant recipients. Prophylactic, preemptive, and hybrid prevention strategies have traditionally been the mainstay of CMV prevention but there is growing interest in the use of CMV cell-mediated immune assays to inform novel approaches to risk stratification. Recent evidence suggests that CMV interferon-gamma release assays can offer predictive insights into the risk for CMV-related illnesses, raising the potential for tailored CMV prevention strategies anchored to each individual's unique CMV immune profile. However, the predictive capacity of these assays for CMV-related illnesses can be profoundly influenced by when they are performed relative to transplant, and the induction immunosuppressive regimen the patient has received. In this review, we explore the relevant literature shaping our understanding of the optimal use of these assays. Furthermore, we also highlight the benefits of quantifying the CD4+ and CD8+ T-Cell responses to CMV, which is offered by some interferon-gamma release assays utilizing intracellular cytokine staining, for providing a holistic assessment of the recovery of cell-mediated immunity post-induction immunosuppression.

Anti-thymocyte globulin for treatment of T-cell-mediated allograft rejection

Anti-thymocyte globulin (ATG) is a pivotal immunosuppressive therapy utilized in the management of T-cell-mediated rejection and steroid-resistant rejection among renal transplant recipients. Commercially available as Thymoglobulin (rabbit-derived, Sanofi, United States), ATG-Fresenius S (rabbit-derived), and ATGAM (equine-derived, Pfizer, United States), these formulations share a common mechanism of action centered on their interaction with cell surface markers of immune cells, imparting immunosuppressive effects. Although the prevailing mechanism predominantly involves T-cell depletion via the com plement-mediated pathway, alternate mechanisms have been elucidated. Optimal dosing and treatment duration of ATG have exhibited variance across ran domised trials and clinical reports, rendering the establishment of standardized guidelines a challenge. The spectrum of risks associated with ATG administration spans from transient adverse effects such as fever, chills, and skin rash in the acute phase to long-term concerns related to immunosuppression, including susceptibility to infections and malignancies. This comprehensive review aims to provide a thorough exploration of the current understanding of ATG, encom passing its mechanism of action, clinical utility in the treatment of acute renal graft rejections, specifically steroid-resistant cases, efficacy in rejection episode reversal, and a synthesis of findings from different eras of maintenance immunosuppression. Additionally, it delves into the adverse effects associated with ATG therapy and its impact on long-term graft function. Furthermore, the review underscores the existing gaps in evidence, particularly in the context of the Banff classification of rejections, and highlights the challenges faced by clinicians when navigating the available literature to strike the optimal balance between the risks and benefits of ATG utilization in renal transplantation.

A Decade of Experience With Alemtuzumab Therapy for Severe or Glucocorticoid-Resistant Kidney Transplant Rejection

Alemtuzumab is used as lymphocyte-depleting therapy for severe or glucocorticoid-resistant kidney transplant rejection. However, the long-term efficacy and toxicity of alemtuzumab therapy are unclear. Therefore, all cases of alemtuzumab anti-rejection therapy between 2012 and 2022 in our institution were investigated. Graft survival, graft function, lymphocyte depletion, serious infections, malignancies, and patient survival were analyzed and compared with a reference cohort of transplanted patients who did not require alemtuzumab anti-rejection therapy. A total of 225 patients treated with alemtuzumab were identified and compared with a reference cohort of 1,668 patients. Over 60% of grafts was salvaged with alemtuzumab therapy, but graft survival was significantly poorer compared to the reference cohort. The median time of profound T- and B lymphocyte depletion was 272 and 344 days, respectively. Serious infection rate after alemtuzumab therapy was 54.1/100 person-years. The risk of death (hazard ratio 1.75, 95%-CI 1.28-2.39) and infection-related death (hazard ratio 2.36, 95%-CI 1.35-4.11) were higher in the alemtuzumab-treated cohort. In conclusion, alemtuzumab is an effective treatment for severe kidney transplant rejection, but causes long-lasting lymphocyte depletion and is associated with frequent infections and worse patient survival outcomes.

Very Low Dose Anti-Thymocyte Globulins Versus Basiliximab in Non-Immunized Kidney Transplant Recipients

The choice between Basiliximab (BSX) or Anti-Thymocyte Globulin (ATG) as induction therapy in non-immunized kidney transplant recipients remains uncertain. Whilst ATG may allow steroid withdrawal and a decrease in tacrolimus, it also increases infectious complications. We investigated outcomes in non-immunized patients receiving a very low dosage of ATG versus BSX as induction. Study outcomes were patient/graft survival, cumulative probabilities of biopsy proven acute rejection (BPAR), infectious episode including CMV and post-transplant diabetes (PTD). Cox, logistic or linear statistical models were used depending on the studied outcome and models were weighted on propensity scores. 100 patients received ATG (mean total dose of 2.0 mg/kg) and 83 received BSX. Maintenance therapy was comparable. Patient and graft survival did not differ between groups, nor did infectious complications. There was a trend for a higher occurrence of a first BPAR in the BSX group (HR at 1.92; 95%CI: [0.77; 4.78]; p = 0.15) with a significantly higher BPAR episodes (17% vs 7.3%, p = 0.01). PTD occurrence was significantly higher in the BSX group (HR at 2.44; 95%CI: [1.09; 5.46]; p = 0.03). Induction with a very low dose of ATG in non-immunized recipients was safe and associated with a lower rate of BPAR and PTD without increasing infectious complications.

ATG-Fresenius increases the risk of red blood cell transfusion after kidney transplantation

Introduction

In sensitized deceased donor kidney allograft recipients, the most frequent induction therapy is anti-thymocyte globulins (ATG), including Thymoglobulin® (Thymo) and ATG-Fresenius (ATG-F).

Methods

We conducted a 3-year monocentric observational study to compare the impact of ATGs on hematological parameters. We included adult kidney transplant recipients treated with ATG induction therapy, either Thymo or ATG-F, on a one-in-two basis. The primary endpoint was red blood cell (RBC) transfusions within 14 days after transplantation.

Results

Among 309 kidney allograft recipients, 177 (57.2%) received ATG induction, 90 (50.8 %) ATG-F, and 87 (49.2%) Thymo. The ATG-F group received significantly more RBC transfusions (63.3% vs. 46% p = 0.02) and in bigger volumes (p = 0.01). Platelet transfusion was similar in both groups. Within 14 and 30 days after transplantation, older age, ATG-F induction, and early surgical complication were independently associated with RBC transfusion. Patient survival rate was 95%, and the death-censored kidney allograft survival rate was 91.5% at 12 months post-transplantation. There was no difference in the incidence of acute rejection and infections or in the prevalence of anti-HLA donor-specific antibodies.

Discussion

In conclusion, after kidney transplantation, ATG-F is an independent risk factor for early RBC transfusion and early thrombocytopenia without clinical and biological consequences. These new data should be clinically considered, and alternatives to ATG should be further explored.

Pharmacotherapeutic options for the prevention of kidney transplant rejection: the evidence to date

INTRODUCTION

Although early rejection episodes are successfully controlled, the problem of unrecognized production of de novo anti HLA antibodies and associated chronic rejection still persists.

AREAS COVERED

In addition to the standard induction and maintenance therapy, we present a couple of new drugs as induction (Alemtuzumab), CNI free protocol (Belatacept, Sirolimus, Everolimus), maintenance treatment in transplant patients with various type of malignancies (T cell targeted immunomodulators blocking the immune checkpoints CTLA-4, PD1/PDL1) and TMA (aHUS) -eculizimab, and IL6 receptor antagonists in antibody mediated rejection (AMR).

EXPERT OPINION

There are couple of issues still preventing improvement in kidney transplant long-term outcomes with current and anticipated future immunosuppression: patient more susceptible to infection and CNI nephrotoxicity in kidneys obtained from elderly donors, highly sensitized patients with limited chances to get appropriate kidney and a higher risk for late AMR. A lower rate of CMV/BK virus infections has been observed in everolimus treated patients. Belatacept use has been justified only in EBV seropositive kidney transplants due to the increased risk of PTLD. Eculizumab upon recurrence of aHUS is a sole cost-effective option. A new IL-6 blocking drug (clazakizumab/tocilizumab) is promising option for prevention/treatment of AMR. Clinical experience in tailoring immunosuppression for as long as possible graft and patient survival is inevitable.

Death With a Functioning Graft Kidney: A Single-Center Experience of More Than 4 Decades

OBJECTIVES

Death with graft function is one of the most catastrophic events after kidney transplant. Various pre and posttransplant risk factors have been linked to death with graft function. Characterization of this event is crucial to set successful preventive measures. Here, we reported on death with graft function among living donor kidney transplant recipients seen at the Urology and Nephrology Centre at Mansoura University (Mansoura, Egypt) throughout a period of >4 decades.

MATERIALS AND METHODS

This single-center study included 2953 patients who received living donor kidney transplant between March 1976 and December 2018. Patient data were retrospectively analyzed. Patients who had death with graft function were compared with other patients with regard to pre- and posttransplant data. Causes of death with graft function were also studied.

RESULTS

Among our patients (1654 male [56%] and 1299 female [44%] patients), death with graft function was reported in 9.9% of patients and responsible for 58.3% of deaths and 24.6% of graft losses. Male sex, pretransplant dialysis and blood transfusion, pre- and posttransplant diabetes and hypertension, high HLA mismatches, antithymocyte globulin induction, steroid and cyclosporine use, steroid dose, acute rejection episodes, and posttransplant infections and malignancy were significantly higher among the death with graft function group. However, multivariate analyses showed that only pretransplant diabetes, steroid dose, and posttransplant infections were risk factors for death with graft function. The most common causes of death with graft function were cardiovascular disease, infections, and malignancy.

CONCLUSIONS

Death with graft function remains a significant hindrance to competent kidney transplant outcomes. We found that the most common contributors to this major event were cardiovascular disease, infections, and malignancy. More attention is needed to modify risk factors of cardiovascular disease, to update implementation policies for posttransplant vaccinations, and to conduct increased malignancy surveillance, as well to adopt less aggressive immunosuppression regimens.

Approaches for Controlling Antibody-Mediated Allograft Rejection Through Targeting B Cells

Both acute and chronic antibody-mediated allograft rejection (AMR), which are directly mediated by B cells, remain difficult to treat. Long-lived plasma cells (LLPCs) in bone marrow (BM) play a crucial role in the production of the antibodies that induce AMR. However, LLPCs survive through a T cell-independent mechanism and resist conventional immunosuppressive therapy. Desensitization therapy is therefore performed, although it is accompanied by severe side effects and the pathological condition may be at an irreversible stage when these antibodies, which induce AMR development, are detected in the serum. In other words, AMR control requires the development of a diagnostic method that predicts its onset before LLPC differentiation and enables therapeutic intervention and the establishment of humoral immune monitoring methods providing more detailed information, including individual differences in the susceptibility to immunosuppressive agents and the pathological conditions. In this study, we reviewed recent studies related to the direct or indirect involvement of immunocompetent cells in the differentiation of naïve-B cells into LLPCs, the limitations of conventional methods, and the possible development of novel control methods in the context of AMR. This information will significantly contribute to the development of clinical applications for AMR and improve the prognosis of patients who undergo organ transplantation.

The Management of Immunosuppression in Kidney Transplant Recipients with COVID-19 Disease: An Update and Systematic Review of the Literature

Background and Objectives: In the era of the coronavirus disease 2019 (COVID-19) pandemic, the management of immunosuppressive (IS) therapy in kidney transplant (KT) recipients affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requires attention. It is not yet understood whether IS therapy may protect from the cytokine storm induced by SARS-CoV-2 infection or a temporary adjustment/withdrawal of IS therapy to restore the immune system may be necessary. We performed a systematic literature review to investigate the current management of IS therapy in KT recipients with COVID-1. Materials and Methods: Out of 71 articles published from 1 February 2020 until 30 October 2020, 554 KT recipients with SARS-CoV-2 infection were identified. Results: Modifications of IS therapy were based on the clinical conditions. For asymptomatic patients or those with mild COVID-19 symptoms, a "wait and see approach" was mostly used; a suspension of antimetabolites drugs (347/461, 75.27%) or mTOR inhibitors (38/48, 79.2%) was adopted in the majority of patients with symptomatic COVID-19 infections. For CNIs, the most frequent attitude was their maintenance (243/502, 48.4%) or dose-reduction (99/502, 19.72%) in patients asymptomatic or with mild COVID-19 symptoms, while drug withdrawal was the preferred choice in severely symptomatic patients (160/450, 31.87%). A discontinuation of all IS drugs was used only in severely symptomatic COVID-19 patients on invasive mechanical ventilation. Renal function remained stable in 422(76.17%) recipients, while 49(8.84%) patients experienced graft loss. Eight (1.44%) patients experienced a worsening of renal function. The overall mortality was 21.84%, and 53(9.56%) patients died with functioning grafts. Conclusion: A tailored approach to the patient has been the preferred strategy for the management of IS therapy in KT recipients, taking into account the clinical conditions of patients and the potential interactions between IS and antiviral drugs, in the attempt to balance the risks of COVID-19-related complications and those due to rejection or graft loss.

Outcomes of kidney transplantation over a 16-year period in Korea: An analysis of the National Health Information Database

BACKGROUND

This study investigated the outcomes of kidney transplantation (KT) over a 16-year period in Korea and identified risk factors for graft failure using a nationwide population-based cohort.

METHODS

We investigated the Korean National Health Insurance Service-National Health Information Database. Health insurance claims for patients who underwent KT between 2002 and 2017 were analyzed.

RESULTS

The data from 18,331 patients who underwent their first KT were reviewed. The percentage of antithymocyte globulin (ATG) induction continuously increased from 2.0% in 2002 to 23.5% in 2017. Rituximab began to be used in 2008 and had increased to 141 patients (9.6%) in 2013. Acute rejection occurred in 17.3% of all patients in 2002 but decreased to 6.3% in 2017. The rejection-free survival rates were 78.8% at 6 months after KT, 76.1% after 1 year, 67.5% after 5 years, 61.7% after 10 years, and 56.7% after 15 years. The graft survival rates remained over 80% until 12 years after KT, and then rapidly decreased to 50.5% at 16 years after KT. In Cox's multivariate analysis, risk factors for graft failure included being male, more recent KT, KT from deceased donor, use of ATG, basiliximab, or rituximab, tacrolimus use as an initial calcineurin inhibitor, acute rejection history, and cytomegalovirus infection.

CONCLUSIONS

ATG and rituximab use has gradually increased in Korea and more recent KT is associated with an increased risk of graft failure. Therefore, meticulous preoperative evaluation and postoperative management are necessary in the case of recent KT with high risk of graft failure.

T cell reconstitution after lymphocyte depletion features a different pattern of inhibitory receptor expression in ABO- versus HLA-incompatible kidney transplant recipients

Chronic antigen stimulation can lead to immune exhaustion (a state of T cell dysfunction). Several phenotypical signatures of T cell exhaustion have been described in various pathological situations, characterized by aberrant expression of multiple inhibitory receptors (IR). This signature has been barely studied in the context of allogenic organ transplantation. We undertook a cross-sectional analysis of the expression of IR [CD244, CD279, T cell immunoreceptor with immunoglobulin (Ig) and immunoreceptor tyrosine-based inhibition motif (ITIM) domains (TIGIT) and CD57] and their correlation with cytokine-producing functions in T cells reconstituting after lymphocyte depletion in patients transplanted from living donors, with preformed donor-specific antibodies. After ABO incompatible transplantation, T cells progressively acquired a phenotype similar to healthy donors and the expression of several IR marked cells with increased functions, with the exception of TIGIT, which was associated with decreased cytokine production. In stark contrast, T cell reconstitution in patients with anti-human leukocyte antigen (HLA) antibodies was characterized with an increased co-expression of IR by T cells, and specifically by an increased expression of TIGIT. Furthermore, expression of these receptors was no longer directly correlated to cytokine production. These results suggest that T cell alloreactivity in HLA-incompatible kidney transplantation drives an aberrant T cell reconstitution with respect to IR profile, which could have an impact on the transplantation outcome.

Update on Immunosuppression in Liver Transplantation

The standard therapy for decompensated end-stage chronic liver disease of any etiology and acute fulminant hepatic failure is liver transplantation (LT). Advances in immunosuppressive therapy decreased the rates of acute and chronic rejections. Thus, graft and patient survivals have significantly improved. However, long-term adverse effects of prolonged use of immunosuppressive agents such as malignancies, opportunistic infections, metabolic disorders, and other organ toxicities have now become a major concern. Consequently, alternative approaches are needed to deescalate the customary drugs and their side effects. Therapy must be individualized and additional preventive measures should be taken by patients with particular risk factors or predisposed to certain adverse effects. Current opinion favors a combination of agents with different mechanism of actions and toxicity profiles. Corticosteroids are employed in immediate and early postoperative period. Although they have a pronounced side effect profile, calcineurin inhibitors (CNIs) are still the backbone of early and late phase immunosuppressive regimens because of their proved efficacy. Antimetabolites are frequent choices for steroid and/or CNI-sparing strategies. Studies also have established a role for mammalian target of rapamycin (mTOR) inhibitors in specific groups of recipients. Biologic agents are a hot topic of interest and made their way into current strategies for induction. Agents extrapolated from other transplantation or immunologic experience are being evaluated.

The Efficacy of Rabbit Anti-Thymocyte Globulin for Acute Kidney Transplant Rejection in Patients Using Calcineurin Inhibitor and Mycophenolate Mofetil-Based Immunosuppressive Therapy

Background

T cell depleting antibody therapy with rabbit anti-thymocyte globulin (rATG) is the treatment of choice for glucocorticoid-resistant acute kidney allograft rejection (AR) and is used as first-line therapy in severe AR. Almost all studies investigating the effectiveness of rATG for this indication were conducted at the time when cyclosporine A and azathioprine were the standard of care. Here, the long-term outcome of rATG for AR in patients using the current standard immunosuppressive therapy (i.e., tacrolimus and mycophenolate mofetil) is described.

Material/Methods

Between 2002 to 2012, 108 patients were treated with rATG for AR. Data on kidney function in the year following rATG and long-term outcomes were collected.

Results

Overall survival after rATG was comparable to overall survival of all kidney transplantation patients (P=0.10). Serum creatinine 1 year after rATG was 179 μmol/L (interquartile range (IQR) 136–234 μmol/L) and was comparable to baseline serum creatinine (P=0.22). Early AR showed better allograft survival than late AR (P=0.0007). In addition, 1 year after AR, serum creatinine was lower in early AR (157 mol/L; IQR 131–203) compared to late AR (216 mol/L; IQR 165–269; P<0.05). The Banff grade of rejection, kidney function at the moment of rejection, and reason for rATG (severe or glucocorticoid resistant AR) did not influence the allograft survival.

Conclusions

Treatment of AR with rATG is effective in patients using current standard immunosuppressive therapy, even in patients with poor allograft function. Early identification of AR followed by T cell depleting treatment leads to better allograft outcomes.