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

Impact of varied immunosuppressive agents and posttransplant diabetes mellitus on prognosis among diverse transplant recipients (Experimental studies)

The success of solid organ transplantation (SOT) and the use of immunosuppressive agents offer hope to patients with end-stage diseases. However, the impact of posttransplant diabetes mellitus (PTDM) on SOT patients has become increasingly evident. In our study, we utilized the Scientific Registry of Transplant Recipients (SRTR) database to investigate the association between PTDM and patient survival in various types of organ transplantations, including liver, kidney, intestinal, heart, lung, and combined heart-lung transplantations (all P<0.001). Our findings revealed a negative effect of PTDM on the survival of these patients. Furthermore, we examined the effects of both generic and innovator immunosuppressive agents on the development of PTDM and the overall survival of different SOT populations. Interestingly, the results were inconsistent, indicating that the impact of these agents may vary depending on the specific type of transplantation and patient population. Overall, our study provides a comprehensive and systematic assessment of the effects of different immunosuppressive agents on prognosis, as well as the impact of PTDM on the survival of patients undergoing various types of SOT. These findings emphasize the need for further research and highlight the importance of optimizing immunosuppressive regimens and managing PTDM in SOT patients to improve their long-term outcomes.

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.

Induction with ATG in DCD kidney transplantation; efficacy and relation of dose and cell markers on delayed graft function and renal function

AIM

We aimed to analyse the efficacy of the Thymoglobulin dose used for induction in controlled DCD kidneys, and its initial impact on blood cell and CD3 count, as predictors of efficacy.

METHODS

140 DCD patients who received ATG induction, were analysed. Intended dose was 1.25 mg/kg/day over 5 days, rounded to nearest 25 mg and not exceeding 125 mg/dose. Outcomes included the total dose in relation with rejection, DGF, graft survival, eGFR. The cell count response to ATG was assessed as predictors of outcome.

RESULTS

Graft survival, was 96.2%, 92.4%, 85% at 1, 3 and 5 years. Rejection was 7% at 1 year and associated with eGFR at 3 (p = 0.003) and 5 years. ATG dose was not predictive of rejection but was associated with the day5 leucocyte and lymphocyte count (p < 0.001) and negatively with DGF (p = 0.05). In 31 patients day3 CD3 count was available and it was associated with rejection (p = 0.002), less DGF (p = 0.09), and 3 years eGFR (p = 0.01).

CONCLUSION

Thymoglobulin provides excellent results in DCD kidneys that do not significantly differ with small dose variations. In higher doses it reduces DGF. Lymphocytes and CD3 count, may be useful surrogate markers of efficacy and outcome.

Delayed graft function is correlated with graft loss in recipients of expanded-criteria rather than standard-criteria donor kidneys: a retrospective, multicenter, observation cohort study

Background:

Although the use of expanded-criteria donors (ECDs) alleviates the problem of organ shortage, it significantly increases the incidence of delayed graft function (DGF). DGF is a common complication after kidney transplantation; however, the effect of DGF on graft loss is uncertain based on the published literature. Hence, the aim of this study was to determine the relationship between DGF and allograft survival.

Methods:

We conducted a retrospective, multicenter, observation cohort study. A total of 284 deceased donors and 541 recipients between February 2012 and March 2017 were included. We used logistic regression analysis to verify the association between clinical parameters and DGF, and Cox proportional hazards models were applied to quantify the hazard ratios of DGF for kidney graft loss.

Results:

Among the 284 deceased donors, 65 (22.8%) donors were ECD. Of the 541 recipients, 107 (19.8%) recipients developed DGF, and this rate was higher with ECD kidneys than with standard-criteria donor (SCD) kidneys (29.2% vs. 17.1%; P = 0.003). The 5-year graft survival rate was not significantly different between SCD kidney recipients with and without DGF (95.8% vs. 95.4%; P = 0.580). However, there was a significant difference between ECD kidney recipients with and without DGF (71.4% vs. 97.6%; P = 0.001), and the adjusted hazard ratio (HR) for graft loss for recipients with DGF was 1.885 (95% confidence interval [CI] = 1.305–7.630; P = 0.024). Results showed that induction therapy with anti-thymocyte globulin was protective against DGF (odds ratio = 0.359; 95% CI = 0.197–0.652; P = 0.001) with all donor kidneys and a protective factor for graft survival (HR = 0.308; 95% CI = 0.130–0.728; P = 0.007) with ECD kidneys.

Conclusion:

DGF is an independent risk factor for graft survival in recipients with ECD kidneys, but not SCD kidneys.

Predictors and one-year outcomes of patients with delayed graft function after deceased donor kidney transplantation

BACKGROUND

Delayed graft function (DGF) is closely associated with the use of marginal donated kidneys due to deficits during transplantation and in recipients. We aimed to predict the incidence of DGF and evaluate its effect on graft survival.

METHODS

This retrospective study on kidney transplantation was conducted from January 1, 2018, to December 31, 2019, at the Second Xiangya Hospital of Central South University. We classified recipients whose operations were performed in different years into training and validation cohorts and used data from the training cohort to analyze predictors of DGF. A nomogram was then constructed to predict the likelihood of DGF based on these predictors.

RESULTS

The incidence rate of DGF was 16.92%. Binary logistic regression analysis showed correlations between the incidence of DGF and cold ischemic time (CIT), warm ischemic time (WIT), terminal serum creatine (Scr) concentration, duration of pretransplant dialysis, primary cause of donor death, and usage of LifePort. The internal accuracy of the nomogram was 83.12%. One-year graft survival rates were 93.59 and 99.74%, respectively, for the groups with and without DGF (P < 0.05).

CONCLUSION

The nomogram established in this study showed good accuracy in predicting DGF after deceased donor kidney transplantation; additionally, DGF decreased one-year graft survival.

Immunosuppression in Donation After Circulatory Death Liver Transplantation: Can Induction Modify Graft Survival?

Recipients of donation after circulatory death (DCD) LTs historically have an increased risk of graft failure. Antibody induction (AI) with antithymocyte globulin (ATG) or anti-interleukin 2 receptor (anti-IL2R) immunotherapy may decrease the incidence of graft failure by mitigating ischemia/reperfusion injury. A retrospective review of the United Network for Organ Sharing (UNOS) database for LTs between 2002 and 2015 was conducted to determine whether ATG or anti-IL2R AI was associated with graft survival in DCD. A secondary endpoint was postoperative renal function as measured by estimated glomerular filtration rate at 6 and 12 months. Among DCD recipients, ATG (hazard ratio [HR] = 0.71; P = 0.03), but not anti-IL2R (HR = 0.82; P = 0.10), was associated with a decrease in graft failure at 3 years when compared with recipients without AI. ATG (HR = 0.90; P = 0.02) and anti-IL2R (HR = 0.94; P = 0.03) were associated with a decreased risk of graft failure in donation after brain death (DBD) liver recipients at 3 years compared with no AI. When induction regimens were compared between DCD and DBD, only ATG (HR = 1.19; P = 0.19), and not anti-IL2R (HR = 1.49; P < 0.01) or no AI (HR = 1.77; P < 0.01), was associated with similar survival between DCD and DBD. In conclusion, AI therapy with ATG was associated with improved longterm liver allograft survival in DCD compared with no AI. ATG was associated with equivalent graft survival between DCD and DBD, suggesting a beneficial role of immune cell depletion in DCD outcomes.

Utility and safety of early allograft biopsy in adult deceased donor kidney transplant recipients

INTRODUCTION

Delayed graft function (DGF) is considered a risk factor for rejection after kidney transplantation (KTx). Clinical guidelines recommend weekly allograft biopsy until DGF resolves. However, who may benefit the most from such an aggressive policy and when histology should be evaluated remain debated.

METHODS

We analyzed 223 biopsies in 145 deceased donor KTx treated with basiliximab or anti-thymocyte globulin (rATG) and calcineurin inhibitor-based maintenance. The aim of the study was to assess the utility and safety of biopsies performed within 28 days of transplant. Relationships between transplant characteristics, indication, timing, and biopsy-related outcomes were evaluated.

RESULTS

Main indication for biopsy was DGF (87.8%) followed by lack of improvement in graft function (9.2%), and worsening graft function (3.1%). Acute tubular necrosis was the leading diagnosis (89.8%) whereas rejection was detected in 8.2% specimens. Rejection was more frequent in patients biopsied due to worsening graft function or lack of improvement in graft function than DGF (66.7% vs. 3.5%; P = 0.0075 and 33.3% vs. 3.5%; P = 0.0104, respectively) and in biopsies performed between day 15 and 28 than from day 0 to 14 (31.2% vs. 3.7%; P = 0.0002). Complication rate was 4.1%. Management was affected by the information gained with histology in 12.2% cases (7% considering DGF).

CONCLUSIONS

In low-immunological risk recipients treated with induction and calcineurin inhibitors maintenance, protocol biopsies obtained within 2 weeks of surgery to rule out rejection during DGF do not necessarily offer a favourable balance between risks and benefits. In these patients, a tailored approach may minimize complications thus optimizing results.

The future for diagnostic tests of acute kidney injury in critical care: evidence synthesis, care pathway analysis and research prioritisation

BACKGROUND

Acute kidney injury (AKI) is highly prevalent in hospital inpatient populations, leading to significant mortality and morbidity, reduced quality of life and high short- and long-term health-care costs for the NHS. New diagnostic tests may offer an earlier diagnosis or improved care, but evidence of benefit to patients and of value to the NHS is required before national adoption.

OBJECTIVES

To evaluate the potential for AKI in vitro diagnostic tests to enhance the NHS care of patients admitted to the intensive care unit (ICU) and identify an efficient supporting research strategy.

DATA SOURCES

We searched ClinicalTrials.gov, The Cochrane Library databases, Embase, Health Management Information Consortium, International Clinical Trials Registry Platform, MEDLINE, metaRegister of Current Controlled Trials, PubMed and Web of Science databases from their inception dates until September 2014 (review 1), November 2015 (review 2) and July 2015 (economic model). Details of databases used for each review and coverage dates are listed in the main report.

REVIEW METHODS

The AKI-Diagnostics project included horizon scanning, systematic reviewing, meta-analysis of sensitivity and specificity, appraisal of analytical validity, care pathway analysis, model-based lifetime economic evaluation from a UK NHS perspective and value of information (VOI) analysis.

RESULTS

The horizon-scanning search identified 152 potential tests and biomarkers. Three tests, Nephrocheck^® (Astute Medical, Inc., San Diego, CA, USA), NGAL and cystatin C, were subjected to detailed review. The meta-analysis was limited by variable reporting standards, study quality and heterogeneity, but sensitivity was between 0.54 and 0.92 and specificity was between 0.49 and 0.95 depending on the test. A bespoke critical appraisal framework demonstrated that analytical validity was also poorly reported in many instances. In the economic model the incremental cost-effectiveness ratios ranged from £11,476 to £19,324 per quality-adjusted life-year (QALY), with a probability of cost-effectiveness between 48% and 54% when tests were compared with current standard care.

LIMITATIONS

The major limitation in the evidence on tests was the heterogeneity between studies in the definitions of AKI and the timing of testing.

CONCLUSIONS

Diagnostic tests for AKI in the ICU offer the potential to improve patient care and add value to the NHS, but cost-effectiveness remains highly uncertain. Further research should focus on the mechanisms by which a new test might change current care processes in the ICU and the subsequent cost and QALY implications. The VOI analysis suggested that further observational research to better define the prevalence of AKI developing in the ICU would be worthwhile. A formal randomised controlled trial of biomarker use linked to a standardised AKI care pathway is necessary to provide definitive evidence on whether or not adoption of tests by the NHS would be of value.

STUDY REGISTRATION

The systematic review within this study is registered as PROSPERO CRD42014013919.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Duration of delayed graft function and outcomes after kidney transplantation from controlled donation after circulatory death donors: a retrospective study

The impact of the duration of delayed graft function (DGF) on graft survival is poorly characterized in controlled donation after circulatory death (DCD) donor kidney transplantation. A retrospective analysis was performed on 225 DCD donor kidney transplants between 2011 and 2016. When patients with primary nonfunction were excluded (n = 9), 141 recipients (65%) had DGF, with median (IQR) duration of dialysis dependency of 6 (2-11.75) days. Longer duration of dialysis dependency was associated with lower estimated glomerular filtration rate at 1 year, and a higher rate of acute rejection. On Kaplan-Meier analysis, the presence of DGF was associated with lower graft survival (log-rank test P = 0.034), though duration of DGF was not (P = 0.723). However, multivariable Cox regression analysis found that only acute rejection was independently associated with lower graft survival [HR (95% CI) 4.302 (1.617-11.450); P = 0.003], whereas the presence of DGF and DGF duration were not. In controlled DCD kidney transplantation, DGF duration itself may not be independently associated with graft survival; rather, it may be that acute rejection associated with prolonged DGF is the poor prognostic factor.

Impact of Donor Age on Clinical Outcomes of Primary Single Kidney Transplantation From Maastricht Category-III Donors After Circulatory Death

BACKGROUND

Standard-criteria donation after circulatory death (DCD) kidney transplants (KTx) have higher primary nonfunction, delayed graft function (DGF), and rejection rates than age-matched donation after brain death (DBD) but similar graft survival. Data on expanded-criteria DCD are conflicting and many centers remain concerned regarding their use.

METHODS

In this single-center observational study with 5-year follow-up, we analyzed data from 112 primary DCD Maastricht category-III single KTx receiving similar organ preservation and maintenance immunosuppression. Patients were sorted as young DCD (donor <60 years, 72 recipients) or old DCD (donor ≥60 years, 40 recipients). Old DCD outcomes were compared with young DCD and to a DBD control group (old DBD, donor ≥60 years, 40 recipients).

RESULTS

After 5 years, old DCD showed lower patient survival (66% vs 85%; P = 0.014), death-censored graft survival (63% vs 83%; P = 0.001), and Modification of Diet in Renal Disease estimated glomerular filtration rate (34, 27.0-42.0 mL/min per 1.73 m2 vs 45.0, 33.0-58.0 mL/min per 1.73 m2; P = 0.021) than young DCD with higher DGF (70% vs 47.2%; P = 0.029) and graft thrombosis (12.5% vs 1.4%; P = 0.021). Comparison between old DCD and old DBD showed similar 5-year patient survival (66% vs 67%; P = 0.394) and death-censored graft survival (63% vs 69%; P = 0.518) but higher DGF (70% vs 37.5%; P = 0.007) and lower estimated glomerular filtration rate (34, 27.0-42.0 mL/min per 1.73 m2 vs 41, 40.0-42.0 mL/min per 1.73 m2; P = 0.029). Multivariate Cox regression analysis showed that donor 60 years or older (hazard ratio, 3.135; 95% confidence interval, 1.716-5.729; P < 0.001) and induction with anti-IL2-receptor-α monoclonal antibody (hazard ratio, 0.503; 95% confidence interval, 0.269-0.940, P = 0.031 in favor of induction with rabbit antithymocyte globulin) are independent predictors of transplant loss.

CONCLUSIONS

Overall, single KTx from DCD Maastricht category-III donors 60 years or older have inferior outcomes than KTx from donors younger than 60 years. Comparison with age-matched DBD showed similar patient and graft survivals. However, the discrepancy in graft function between DCD and DBD deserves further investigation.

Does Rabbit Antithymocyte Globulin (Thymoglobuline®) Have a Role in Avoiding Delayed Graft Function in the Modern Era of Kidney Transplantation?

Delayed graft function (DGF) increases the risk of graft loss by up to 40%, and recent developments in kidney donation have increased the risk of its occurrence. Lowering the risk of DGF, however, is challenging due to a complicated etiology in which ischemia-reperfusion injury (IRI) leads to acute tubular necrosis. Among various strategies explored, the choice of induction therapy is one consideration. Rabbit antithymocyte globulin (rATG [Thymoglobuline]) has complex immunomodulatory effects that are relevant to DGF. In addition to a rapid and profound T-cell depletion, rATG inhibits leukocyte migration and adhesion. Experimental studies of rATG have demonstrated attenuated IRI-related tissue damage in reperfused tissues, consistent with histological evidence from transplant recipients. Starting rATG intraoperatively instead of postoperatively can improve kidney graft function and reduce the incidence of DGF. rATG is effective in preventing acute rejection in kidney transplant recipients at high immunological risk, supporting delayed calcineurin inhibitor (CNI) introduction which protects the graft from early insults. A reduced rate of DGF has been reported with rATG (started intraoperatively) and delayed CNI therapy compared to IL-2RA induction with immediate CNI in patients at high immunological risk, but not in lower-risk patients. Overall, induction with rATG induction is the preferred choice for supporting delayed introduction of CNI therapy to avoid DGF in high-risk patients but shows no benefit versus IL-2RA in lower-risk individuals. Evidence is growing that intraoperative rATG ameliorates IRI, and it seems reasonable to routinely start rATG before reperfusion.

Donation after brain death followed by circulatory death, a novel donation pattern, confers comparable renal allograft outcomes with donation after brain death

BACKGROUND

Organ donation after brain death (DBD) is the standard strategy for organ transplantation; however, the concept of brain death is not universally accepted due to cultural beliefs and barriers amongst billions of people worldwide. Hence, a novel donation pattern has been established in China which outlines the concept of donation after brain death followed by circulatory death (DBCD). Differently from any current donation classification, this new concept is formulated based on combination of recognizing brain death and circulatory death. Should approval be gained for this definition and approach, DBCD will pave a novel donation option for billions of people who cannot accept DBD due to their cultural beliefs.

METHODS

A multi-center, cohort study was conducted from February 2012 to December 2015. 523 kidney transplant recipients from four kidney transplant institutions were enrolled into the study, of which, 383 received kidneys from DBCD, and 140 from DBD. Graft and recipient survivals following transplantation were retrospectively analyzed. Postoperative complications including delayed graft function,, and acute rejection, were also analyzed for both groups.

RESULTS

DBCD could achieve comparable graft and recipient survivals in comparison with DBD (Log-rank P = 0.32 and 0.86,respectively). One-year graft and recipient survivals were equal between DBCD and DBD groups (97.4% versus 97.9%, P = 0.10;98.4% versus 98.6%, P = 1.0, respectively). Furthermore, DBCD did not increase incidences of postoperative complications compared with DBD, including delayed graft function (19.3% versus 22.1%, P = 0.46) and acute rejection (9.1% versus 8.6%, P = 1.0). Additionally, antithymocyte globulin as induction therapy and shorter warm ischemia time decreased incidence of delayed graft function in DBCD group (16.8% on antithymocyte globulin versus 27.2% on basiliximab, P = 0.03; 16.7% on ≤18 min versus 26.7% on > 18 min group, P = 0.03).

CONCLUSIONS

Kidney donation through DBCD achieves equally successful outcomes as DBD, and could provide a feasible path to graft availability for billions of people who face barriers to organ donation from DBD.

Immunosuppressive therapy for kidney transplantation in adults: a systematic review and economic model

BACKGROUND

End-stage renal disease is a long-term irreversible decline in kidney function requiring renal replacement therapy: kidney transplantation, haemodialysis or peritoneal dialysis. The preferred option is kidney transplantation, followed by immunosuppressive therapy (induction and maintenance therapy) to reduce the risk of kidney rejection and prolong graft survival.

OBJECTIVES

To review and update the evidence for the clinical effectiveness and cost-effectiveness of basiliximab (BAS) (Simulect(®), Novartis Pharmaceuticals UK Ltd) and rabbit anti-human thymocyte immunoglobulin (rATG) (Thymoglobulin(®), Sanofi) as induction therapy, and immediate-release tacrolimus (TAC) (Adoport(®), Sandoz; Capexion(®), Mylan; Modigraf(®), Astellas Pharma; Perixis(®), Accord Healthcare; Prograf(®), Astellas Pharma; Tacni(®), Teva; Vivadex(®), Dexcel Pharma), prolonged-release tacrolimus (Advagraf(®) Astellas Pharma), belatacept (BEL) (Nulojix(®), Bristol-Myers Squibb), mycophenolate mofetil (MMF) (Arzip(®), Zentiva; CellCept(®), Roche Products; Myfenax(®), Teva), mycophenolate sodium (MPS) (Myfortic(®), Novartis Pharmaceuticals UK Ltd), sirolimus (SRL) (Rapamune(®), Pfizer) and everolimus (EVL) (Certican(®), Novartis) as maintenance therapy in adult renal transplantation.

METHODS

Clinical effectiveness searches were conducted until 18 November 2014 in MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Central Register of Controlled Trials (via Wiley Online Library) and Web of Science (via ISI), Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Health Technology Assessment (The Cochrane Library via Wiley Online Library) and Health Management Information Consortium (via Ovid). Cost-effectiveness searches were conducted until 18 November 2014 using a costs or economic literature search filter in MEDLINE (via Ovid), EMBASE (via Ovid), NHS Economic Evaluation Database (via Wiley Online Library), Web of Science (via ISI), Health Economic Evaluations Database (via Wiley Online Library) and the American Economic Association's electronic bibliography (via EconLit, EBSCOhost). Included studies were selected according to predefined methods and criteria. A random-effects model was used to analyse clinical effectiveness data (odds ratios for binary data and mean differences for continuous data). Network meta-analyses were undertaken within a Bayesian framework. A new discrete time-state transition economic model (semi-Markov) was developed, with acute rejection, graft function (GRF) and new-onset diabetes mellitus used to extrapolate graft survival. Recipients were assumed to be in one of three health states: functioning graft, graft loss or death.

RESULTS

Eighty-nine randomised controlled trials (RCTs), of variable quality, were included. For induction therapy, no treatment appeared more effective than another in reducing graft loss or mortality. Compared with placebo/no induction, rATG and BAS appeared more effective in reducing biopsy-proven acute rejection (BPAR) and BAS appeared more effective at improving GRF. For maintenance therapy, no treatment was better for all outcomes and no treatment appeared most effective at reducing graft loss. BEL + MMF appeared more effective than TAC + MMF and SRL + MMF at reducing mortality. MMF + CSA (ciclosporin), TAC + MMF, SRL + TAC, TAC + AZA (azathioprine) and EVL + CSA appeared more effective than CSA + AZA and EVL + MPS at reducing BPAR. SRL + AZA, TAC + AZA, TAC + MMF and BEL + MMF appeared to improve GRF compared with CSA + AZA and MMF + CSA. In the base-case deterministic and probabilistic analyses, BAS, MMF and TAC were predicted to be cost-effective at £20,000 and £30,000 per quality-adjusted life-year (QALY). When comparing all regimens, only BAS + TAC + MMF was cost-effective at £20,000 and £30,000 per QALY.

LIMITATIONS

For included trials, there was substantial methodological heterogeneity, few trials reported follow-up beyond 1 year, and there were insufficient data to perform subgroup analysis. Treatment discontinuation and switching were not modelled.

FUTURE WORK

High-quality, better-reported, longer-term RCTs are needed. Ideally, these would be sufficiently powered for subgroup analysis and include health-related quality of life as an outcome.

CONCLUSION

Only a regimen of BAS induction followed by maintenance with TAC and MMF is likely to be cost-effective at £20,000-30,000 per QALY.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014013189.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Cost-Effectiveness of Antibody-Based Induction Therapy in Deceased Donor Kidney Transplantation in the United States

BACKGROUND

Induction therapy in deceased donor kidney transplantation is costly, with wide discrepancy in utilization and a limited evidence base, particularly regarding cost-effectiveness.

METHODS

We linked the United States Renal Data System data set to Medicare claims to estimate cumulative costs, graft survival, and incremental cost-effectiveness ratio (ICER - cost per additional year of graft survival) within 3 years of transplantation in 19 450 deceased donor kidney transplantation recipients with Medicare as primary payer from 2000 to 2008. We divided the study cohort into high-risk (age > 60 years, panel-reactive antibody > 20%, African American race, Kidney Donor Profile Index > 50%, cold ischemia time > 24 hours) and low-risk (not having any risk factors, comprising approximately 15% of the cohort). After the elimination of dominated options, we estimated expected ICER among induction categories: no-induction, alemtuzumab, rabbit antithymocyte globulin (r-ATG), and interleukin-2 receptor-antagonist.

RESULTS

No-induction was the least effective and most costly option in both risk groups. Depletional antibodies (r-ATG and alemtuzumab) were more cost-effective across all willingness-to-pay thresholds in the low-risk group. For the high-risk group and its subcategories, the ICER was very sensitive to the graft survival; overall both depletional antibodies were more cost-effective, mainly for higher willingness to pay threshold (US $100 000 and US $150 000). Rabbit ATG appears to achieve excellent cost-effectiveness acceptability curves (80% of the recipients) in both risk groups at US $50 000 threshold (except age > 60 years). In addition, only r-ATG was associated with graft survival benefit over no-induction category (hazard ratio, 0.91; 95% confidence interval, 0.84-0.99) in a multivariable Cox regression analysis.

CONCLUSIONS

Antibody-based induction appears to offer substantial advantages in both cost and outcome compared with no-induction. Overall, depletional induction (preferably r-ATG) appears to offer the greatest benefits.

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%.

A Proposal for Early Dosing Regimens in Heart Transplant Patients Receiving Thymoglobulin and Calcineurin Inhibition

There is currently no consensus regarding the dose or duration of rabbit antithymocyte globulin (rATG) induction in different types of heart transplant patients, or the timing and intensity of initial calcineurin inhibitor (CNI) therapy in rATG-treated individuals. Based on limited data and personal experience, the authors propose an approach to rATG dosing and initial CNI administration. Usually rATG is initiated immediately after exclusion of primary graft failure, although intraoperative initiation may be appropriate in specific cases. A total rATG dose of 4.5 to 7.5 mg/kg is advisable, tailored within that range according to immunologic risk and adjusted according to immune monitoring. Lower doses (eg, 3.0 mg/kg) of rATG can be used in patients at low immunological risk, or 1.5 to 2.5 mg/kg for patients with infection on mechanical circulatory support. The timing of CNI introduction is dictated by renal recovery, varying between day 3 and day 0 after heart transplantation, and the initial target exposure is influenced by immunological risk and presence of infection. Rabbit antithymocyte globulin and CNI dosing should not overlap except in high-risk cases. There is a clear need for more studies to define the optimal dosing regimens for rATG and early CNI exposure according to risk profile in heart transplantation.

Daclizumab Versus Rabbit Antithymocyte Globulin in High-Risk Renal Transplants: Five-Year Follow-up of a Randomized Study

We previously reported a randomized controlled trial in which 227 de novo deceased-donor kidney transplant recipients were randomized to rabbit antithymocyte (rATG, Thymoglobulin) or daclizumab if they were considered to be at high immunological risk, defined as high panel reactive antibodies (PRA), loss of a first kidney graft through rejection within 2 years of transplantation, or third or fourth transplantation. Patients treated with rATG had lower incidences of biopsy-proven acute rejection (BPAR) and steroid-resistant rejection at 1 year. Patients were followed to 5 years posttransplant in an observational study; findings are described here. Treatment with rATG was associated with a lower rate of BPAR at 5 years (14.2% vs. 26.0% with daclizumab; p = 0.035). Only one rATG-treated patient (0.9%) and one daclizumab-treated patient (1.0%) developed BPAR after 1 year. Five-year graft and patient survival rates, and renal function, were similar between the two groups. Overall graft survival at 5 years was significantly higher in patients without BPAR (81.0% vs. 54.8%; p < 0.001). In conclusion, rATG is superior to daclizumab for the prevention of BPAR among high-immunological-risk renal transplant recipients. Overall graft survival at 5 years was approximately 70% with either induction therapy, which compares favorably to low-risk cohorts.

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.