Prediction of High-Risk Donors for Kidney Discard and Nonrecovery Using Structured Donor Characteristics and Unstructured Donor Narratives.

Importance: Despite the unmet need, many deceased-donor kidneys are discarded or not recovered. Inefficient allocation and prolonged ischemia time are contributing factors, and early detection of high-risk donors may reduce organ loss. Objective: To evaluate the feasibility of machine learning (ML) and natural language processing (NLP) classification of donors with kidneys that are used vs not used for organ transplant. Design, Setting, and Participants: This retrospective cohort study used donor information (structured donor characteristics and unstructured donor narratives) from the United Network for Organ Sharing (UNOS). All donor offers to a single transplant center between January 2015 and December 2020 were used to train and validate ML models to predict donors who had at least 1 kidney transplanted (at our center or another center). The donor data from 2021 were used to test each model. Exposures: Donor information was provided by UNOS to the transplant centers with potential transplant candidates. Each center evaluated the donor and decided within an allotted time whether to accept the kidney for organ transplant. Main Outcomes and Measures: Outcome metrics of the test cohort included area under the receiver operating characteristic curve (AUROC), F1 score, accuracy, precision, and recall of each ML classifier. Feature importance and Shapley additive explanation (SHAP) summaries were assessed for model explainability. Results: The training/validation cohort included 9555 donors (median [IQR] age, 50 [36-58] years; 5571 male [58.3%]), and the test cohort included 2481 donors (median [IQR] age, 52 [40-59] years; 1496 male [60.3%]). Only 20% to 30% of potential donors had at least 1 kidney transplanted. The ML model with a single variable (Kidney Donor Profile Index) showed an AUROC of 0.69, F1 score of 0.42, and accuracy of 0.64. Multivariable ML models based on basic a priori structured donor data showed similar metrics (logistic regression: AUROC = 0.70; F1 score = 0.42; accuracy = 0.62; random forest classifier: AUROC = 0.69; F1 score = 0.42; accuracy = 0.64). The classic NLP model (bag-of-words model) showed its best metrics (AUROC = 0.60; F1 score = 0.35; accuracy = 0.59) by the logistic regression classifier. The advanced Bidirectional Encoder Representations From Transformers model showed comparable metrics (AUROC = 0.62; F1 score = 0.39; accuracy = 0.69) only after appending basic donor information. Feature importance and SHAP detected the variables (and words) that affected the models most. Conclusions and Relevance: Results of this cohort study suggest that models using ML can be applied to predict donors with high-risk kidneys not used for organ transplant, but the models still need further elaboration. The use of unstructured data is likely to expand the possibilities; further exploration of new approaches will be necessary to develop models with better predictive metrics.

Long-term Survival of Grafts From Small and Very Small Pediatric Donors in Women vs Men With End-stage Kidney Disease.

This cohort study compares graft survival of kidneys from small and very small pediatric donors in women vs men with end-stage kidney disease.

How to Deal With Kidney Retransplantation-Second, Third, Fourth, and Beyond.

Kidney transplantation is the best health option for patients with end-stage kidney disease. Ideally, a kidney transplant would last for the lifetime of each recipient. However, depending on the age of the recipient and details of the kidney transplant, there may be a need for a second, third, fourth, or even more kidney transplants. In this overview, the outcome of multiple kidney transplants for an individual is presented. Key issues include surgical approach and immunologic concerns. Included in the surgical approach is an analysis of transplant nephrectomy, with indications, timing, and immunologic impact. Allograft thrombosis, whether related to donor or recipient factors merits investigation to prevent it from happening again. Other posttransplant events such as rejection, viral illness (polyomavirus hominis type I), recurrent disease (focal segmental glomerulosclerosis), and posttransplant lymphoproliferative disease may lead to the need for retransplantation. The pediatric recipient is especially likely to need a subsequent kidney transplant. Finally, noncompliance/nonadherence can affect both adults and children. Innovative approaches may reduce the need for retransplantation in the future.

Combined Ex Vivo Hypothermic and Normothermic Perfusion for Assessment of High-risk Deceased Donor Human Kidneys for Transplantation.

BACKGROUND: Despite careful clinical examination, procurement biopsy and assessment on hypothermic machine perfusion, a significant number of potentially useable deceased donor kidneys will be discarded because they are deemed unsuitable for transplantation. Ex vivo normothermic perfusion (EVNP) may be useful as a means to further assess high-risk kidneys to determine suitability for transplantation. METHODS: From June 2014 to October 2015, 7 kidneys (mean donor age, 54.3 years and Kidney Donor Profile Index, 79%) that were initially procured with the intention to transplant were discarded based on a combination of clinical findings, suboptimal biopsies, long cold ischemia time (CIT) and/or poor hypothermic perfusion parameters. They were subsequently placed on EVNP using oxygenated packed red blood cells and supplemental nutrition for a period of 3 hours. Continuous hemodynamic and functional parameters were assessed. RESULTS: After a mean CIT of 43.7 hours, all 7 kidneys appeared viable on EVNP with progressively increasing renal blood flow over the 3-hour period of perfusion. Five of the 7 kidneys had excellent macroscopic appearance, rapid increase in blood flow to 200 to 250 mL/min, urine output of 40 to 260 mL/h and increasing creatinine clearance. CONCLUSIONS: Favorable perfusion characteristics and immediate function after a 3-hour course of EVNP suggests that high-risk kidneys subjected to long CIT may have been considered for transplantation. The combined use of ex vivo hypothermic and normothermic perfusion may be a useful strategy to more adequately assess and preserve high-risk kidneys deemed unsuitable for transplantation. A clinical trial will be necessary to validate the usefulness of this approach.

Roux-en-Y gastric bypass is an effective bridge to kidney transplantation: Results from a single center.

Body mass index (BMI) > 35-40 kg/m2 is often a contraindication, while Roux-en-Y gastric bypass (RYGB) is performed to enable kidney transplantation. This single-center retrospective study evaluated pre- and post-transplant outcomes of 31 morbidly obese patients with end-stage renal disease having RYGB before kidney transplantation between July 2009 and June 2014. Fourteen RYGB patients were subsequently transplanted. Nineteen recipients not having GB with a BMI ≥ 36 kg/m2 at transplantation were used as historical controls. Mean BMI (±SE) before RYGB was 43.5 ± 0.7 kg/m2 (range: 35.4-50.5 kg/m2 ); 87.1% (27/31) achieved a BMI < 35 kg/m2 . The percentage having improved diabetes/hypertension control was 29.0% (9/31); 25.8% (8/31) had complications (mostly minor) after RYGB. Among transplanted patients, blacks/Hispanics comprised 78.6% (11/14) and 84.2% (16/19) of RYGB and controls; 57.1% (8/14) and 63.2% (12/19) had a (mostly long-standing) pretransplant history of diabetes. While biopsy-proven acute rejection (BPAR) occurred significantly higher among RYGB vs control patients (6/14 vs 3/19, P = .03), patients developing T-cell BPAR were also significantly more likely to have a tacrolimus (TAC) trough level < 4.0 ng/mL within 3 weeks of T-cell BPAR (P = .0007). In Cox's model, the impact of having a TAC level < 4.0 ng/mg remained significant (P = .007) while the effect of RYGB was no longer significant (P = .13). Infections, graft, and patient survival were not significantly different. Despite obvious effectiveness in achieving weight loss, RYGB will need more careful post-transplant monitoring given the observed higher BPAR rate.

Randomized trial of rATg/Daclizumab vs. rATg/Alemtuzumab as dual induction therapy in renal transplantation: Results at 8years of follow-up.

Our goal in using dual induction therapy is to bring the kidney transplant recipient closer (through more effectively timed lymphodepletion) to an optimally immunosuppressed state. Here, we report long-term results of a prospective randomized trial comparing (Group I,N=100) rATG/Dac (3 rATG, 2 Dac doses) vs. (Group II,N=100) rATG/Alemtuzumab(C1H) (1 dose each), using reduced tacrolimus dosing, EC-MPS, and early corticosteroid withdrawal. Lower EC-MPS dosing was targeted in Group II to avoid severe leukopenia. Median follow-up was 96mo post-transplant. There were no differences in 1st BPAR (including borderline) rates: 10/100 vs. 9/100 in Groups I and II during the first 12mo(P=0.54), and 20/100 vs. 20/100 throughout the study(P=0.90). Equally favorable renal function was maintained in both treatment arms(N.S.). While not significant, more patients in Group II experienced graft loss, 25/100 vs. 18/100 in Group I(P=0.23). Actuarial patient/graft survival at 96mo was 92%/83% vs. 85%/73% in Groups I and II(N.S.). DWFG-due-to-infection(N.S.), EC-MPS withholding-due-to-leukopenia during the first 2mo(P=0.03), and incidence of viral infections(P=0.09) were higher in Group II, whereas EC-MPS withholding-due-to-GI symptoms was higher in Group I(P=0.009). No other adverse event differences were observed. While long-term anti-rejection and renal function efficacy were demonstrated in both treatment arms, slight over-immunosuppression of Group II patients occurred.

Lower tacrolimus trough levels are associated with subsequently higher acute rejection risk during the first 12 months after kidney transplantation.

The premise that lower TAC trough levels are associated with subsequently higher first BPAR risk during the first 12 mo post-transplant was recently questioned. Using our prospectively followed cohort of 528 adult, primary kidney transplant recipients (pooled across four randomized trials) who received reduced TAC dosing plus an IMPDH inhibitor, TAC trough levels measured at seven time points, 7, 14 days, 1, 2, 3, 6 and 9 months post-transplant, were utilized along with Cox's model to determine the multivariable significance of TAC level(t) (a continuous time-dependent covariate equaling the most recently measured TAC level prior to time t) on the hazard rate of developing first BPAR during the first 12 months post-transplant. The percentage developing BPAR during the first 12 months post-transplant was 10.2% (54/528). In univariable analysis, lower TAC level(t) was associated with a significantly higher BPAR rate (P = 0.00006), and its significance was maintained even after controlling for 2 significant baseline predictors (African-American/Hispanic Recipient and Developed DGF) in Cox's model (multivariable P = 0.0003). Use of a cutpoint, TAC level(t) <4.0 vs. ≥4.0 ng/ml, yielded an even greater association with BPAR rate (univariable and multivariable P < 0.000001), with an estimated hazard ratio of 6.33. These results suggest that TAC levels <4.0 ng/ml should be avoided during the first 12 months post-transplant when TAC is used in combination with fixed-dose mycophenolate with or without corticosteroids and induction therapy.

Single-centre study of 628 adult, primary kidney transplant recipients showing no unfavourable effect of new-onset diabetes after transplant.

AIMS/HYPOTHESIS: To better understand the implications of new-onset diabetes after transplant (NODAT), we used our prospectively followed cohort of 628 adult primary kidney transplant recipients to determine the prognostic impact of pretransplant diabetes and NODAT. METHODS: The study cohort consisted of all participants in four randomised immunosuppression trials performed at our centre since May 2000. For each cause-specific hazard analysed, Cox stepwise regression was used to determine a multivariable model of significant baseline predictors; the multivariable influence of having pretransplant diabetes and NODAT (t) (the latter defined as a zero-one, time-dependent covariate) was subsequently tested. Similar analyses of estimated glomerular filtration rate (eGFR) at 36 and 60 months post transplant were performed using stepwise linear regression. Finally, a repeated measures analysis of mean HbA1c as a function of diabetes category (pretransplant diabetes vs NODAT) and randomised trial (first to fourth) was performed. RESULTS: Median follow-up was 56 months post transplant. Patients with pretransplant diabetes comprised 23.4% (147/628), and 22.5% (108/481) of the remaining patients developed NODAT. Pretransplant diabetes had no prognostic influence on first biopsy-proven acute rejection and death-censored graft failure hazard rates, nor on eGFR, but was associated with significantly higher rates of death with a functioning graft (DWFG) (p = 0.003), DWFG due to a cardiovascular event (p = 0.005) and infection that required hospitalisation (p = 0.03). NODAT (t) had no unfavourable impact on any of these hazard rates nor on eGFR, with actuarial freedom from DWFG remaining at over 90% among patients in pre- and post-NODAT states at 72 months post transplant/NODAT. Mean HbA1c for patients in the first to fourth randomised trials, averaged across diabetes category, decreased by trial (7.28%, 6.92%, 6.87% and 6.64% [56.1, 52.1, 51.6 and 49.1 mmol/mol], respectively; p = 0.02). CONCLUSIONS/INTERPRETATION: Less-than-expected post-NODAT risk for graft loss and death may exist in the current climate of tighter glucose monitoring post transplant.

Lack of clinical association and effect of peripheral WBC counts on immune cell function test in kidney transplant recipients with T-cell depleting induction and steroid-sparing maintenance therapy.

The Cylex ImmuKnow assay measures the amount of stimulated ATP production by CD4+ T-cells, and has been used clinically, trying to predict rejection and infection episodes. However, predictive values of this assay after induction therapy with steroid-sparing maintenance protocols are unclear. In this single-center cohort study, we analyzed renal transplant recipients who received T-cell depleting+/-anti-IL2 receptor antibodies and tacrolimus/mycophenolate maintenance without steroids. A total of 4224 ImmuKnow levels in 306 patients were available for analysis. ImmuKnow levels (Mean ± SE) changed over time after induction therapy with a paradoxical initial increase: 419 ± 23, 461 ± 32, 519 ± 14, 411 ± 10, 344 ± 6, and 405 ± 3 for pre-transplant, 0-1 wk, 1 wk-1 mo, 1-3 mos, 3 mos-1 yr, and thereafter. This change was parallel to the evolution of peripheral WBC counts and ImmuKnow levels had weak but significant correlation with WBC counts (R(2)=0.264, P<0.0001). The levels for biopsy-proven rejection (389 ± 56) and borderline/clinical rejection (254 ± 41) were not significantly higher than the levels of quiescent patients. The levels for opportunistic infection (349 ± 48) and other infections (345 ± 27) were not significantly lower than the levels of quiescent patients. The longitudinal changes in ImmuKnow levels were not predictive of rejection or infection. In conclusion, ImmuKnow levels can vary after T-cell depleting induction therapies at various time points, even without significant clinical events. Since ImmuKnow levels seem to be affected by WBC counts, ImmuKnow results need to be interpreted with caution. The effects of leukocytosis or leukopenia caused by immunosuppressive medication on the ImmuKnow assay need further investigation.

Randomized trial of three induction antibodies in kidney transplantation: long-term results.

BACKGROUND: In searching for an optimal induction regimen, we conducted two separate randomized trials of 38 living donor and 90 deceased donor adult, primary kidney transplant recipients comparing antithymocyte globulin (Thymoglobulin) (group A, N=43) versus alemtuzumab (group B, N=43) versus daclizumab (group C, N=42), using exactly the same three treatment arms in each trial. METHODS: For the purpose of maximizing statistical power, results from the two randomized trials were combined. Groups A and C received standard maintenance dosing with tacrolimus (TAC), mycophenolate mofetil (MMF), and corticosteroids. Because of intense lymphodepletion expected with alemtuzumab use (and hoped-for achievement of a truer immunoregulatory state), group B received lower TAC and MMF dosing and corticosteroid avoidance. Long-term target TAC trough level and MMF dosing were 5 to 7 ng/mL and 1,000 mg b.i.d. in groups A and C; 4 to 6 ng/mL and 500 mg b.i.d. in group B. RESULTS: With median follow-up of 95 months, biopsy-proven cute rejection incidence was similar in the three groups (8/43, 14/43, and 12/42, P=0.34), but biopsy-proven chronic allograft injury incidence was significantly higher in group B (19/43) in comparison with groups A (9/43) and C (7/42) combined (P=0.0008). Mean calculated creatinine clearance was significantly lower in group B versus the average of groups A and C means throughout 60 months posttransplant (62.9±4.2 vs. 83.6±6.9 and 79.8±5.9 at 60 months, P=0.01), and death-censored graft failure was significantly higher in group B (13/43) versus groups A (5/43) and C (5/42) combined (P=0.009). Total infection and new-onset diabetes after transplant rates were not significantly different. Ad hoc analysis suggested that the inferior results in group B were specifically a result of reduced dosing and greater withholding of TAC and MMF occurring in that group. CONCLUSIONS: Long-term results clearly indicate inferior clinical outcomes in group B.

Successful treatment for graft-versus-host disease after pancreas transplantation.

Graft-versus-host disease (GVHD) after pancreas transplantation is a rare but serious complication: All previously reported cases were fatal. We herein report three cases of GVHD after pancreas transplantation with favorable outcomes. Patients with a history of kidney (and pancreas) transplantation subsequently received a pancreas (and kidney) transplantation (i.e., pancreas retransplantation or pancreas after kidney transplantation) and developed acute GVHD. All of them responded to increased immunosuppression (e.g., steroid bolus, antithymocyte globulin) and retained normal graft function. Because the clinical manifestations are non-specific, vigilance is necessary to make an accurate diagnosis. We underscored the importance of a biopsy of involved organs and the clinicopathologic correlation in the early diagnosis of GVHD. Augmented immunosuppression to prevent progression from a self-limited disease to life-threatening pancytopenia or sepsis may be most critical to improve outcome.

Abatacept in B7-1-positive proteinuric kidney disease.

Abatacept (cytotoxic T-lymphocyte-associated antigen 4-immunoglobulin fusion protein [CTLA-4-Ig]) is a costimulatory inhibitor that targets B7-1 (CD80). The present report describes five patients who had focal segmental glomerulosclerosis (FSGS) (four with recurrent FSGS after transplantation and one with primary FSGS) and proteinuria with B7-1 immunostaining of podocytes in kidney-biopsy specimens. Abatacept induced partial or complete remissions of proteinuria in these patients, suggesting that B7-1 may be a useful biomarker for the treatment of some glomerulopathies. Our data indicate that abatacept may stabilize ß1-integrin activation in podocytes and reduce proteinuria in patients with B7-1-positive glomerular disease.

A randomized pilot study of donor stem cell infusion in living-related kidney transplant recipients receiving alemtuzumab.

BACKGROUND: Transplant tolerance would remove the need for maintenance immunosuppression while improving survival and quality of life. METHODS: A prospective, randomized pilot study was undertaken to assess the safety and efficacy of donor stem cell infusion (DSCI) in living-related kidney transplant recipients treated with alemtuzumab (C1H) induction and tacrolimus and mycophenolate maintenance with switch to sirolimus and weaning over 2 years. RESULTS: Four patients received DSCI; five patients were controls. Graft failure occurred in two patients in the DSCI arm. Recurrence of glomerular disease occurred in two DSCI recipients, leading to graft loss in one. Biopsy-proven acute rejection episodes occurred in three patients (two in the DSCI vs. one in the control). One DSCI patient, with recurrence, subsequently developed antibody-mediated rejection leading to graft failure. In the remaining two DSCI patients, weaning was attempted but was not successful. All (4 of 4) DSCI patients had biopsy-proven chronic allograft injury and/or recurrence. CONCLUSION: DSCI with C1H induction and a steroid-free maintenance regimen in a small group of patients failed to induce tolerance, with suboptimal patient and graft survival. The results do not justify extension of this particular trial and underscore the importance of patient selection, specifically avoidance of patients with glomerulopathies whose recurrence may obscure potential benefit.

Aneurysmectomy with partial nephrectomy on a living donor renal allograft: a case report.

Vascular anomalies among living kidney donors are seldom encountered and their presence offers a complex opportunity for every transplant surgeon. Furthermore, there has been an increasing trend with the use of marginal or kidneys with pathology to address the shortage of organs. We report a rare case of a kidney allograft with a saccular aneurysm and renal cortical cysts for which an excision with primary repair and partial nephrectomy were done, respectively. The recipient was a 45-year-old female with lupus nephritis and significant comorbidities who had excellent recovery and outcome. With good surgical techniques, these types of grafts continue to provide acceptable outcome but safety of the donor should be of utmost importance.

Podocyte foot process effacement in postreperfusion allograft biopsies correlates with early recurrence of proteinuria in focal segmental glomerulosclerosis.

BACKGROUND: Focal segmental glomerulosclerosis (FSGS) is a relatively prevalent glomerular disorder that often progresses to end-stage renal disease. Thirty to 80% of kidney transplant (KT) recipients with FSGS will experience recurrence characterized by proteinuria and podocyte damage. We hypothesized that the degree of podocyte foot process (FP) effacement in postreperfusion transplant biopsies can be used to predict the development of clinical recurrence of FSGS. METHOD: Nineteen pairs of pre- and postreperfusion biopsy specimens were studied. We evaluated the degree of FP effacement in postreperfusion KT biopsies by counting the number of widened FP per capillary loop. Early recurrence of FSGS was defined as development of nephrotic range proteinuria between days 3 and 30 posttransplant. RESULTS: Early recurrence occurred in 7 of 19 grafts (36.8%) at a mean of 4.29±1.89 days. The mean score of FP effacement in postreperfusion allograft biopsies was 0.72±0.31 and 1.35±0.63 in the nonrecurrent and recurrent group, respectively (P=0.039). There was an association between FP effacement and proteinuria (P = 0.04). The FP effacement score predicts early recurrence with a sensitivity of 71.4% and specificity of 91.7%. CONCLUSION: FP effacement can be observed within minutes after reperfusion in renal transplantation of recipients with FSGS that will ultimately develop recurrent FSGS. This suggests a key role for the podocyte injury in the pathogenesis of recurrent FSGS and further supports the presence of circulating factors causing FP effacement. The FP effacement score in the postreperfusion KT biopsy may become a useful predictive test if validated in larger studies.

Machine perfusion following static cold storage preservation in kidney transplantation: donor-matched pair analysis of the prognostic impact of longer pump time.

The impact of machine perfusion (MP) time on kidney transplant outcome is mixed in previous studies using multivariable analyses. In an analysis of 66 pairs of donor-matched adult, first transplant recipients (N = 132) with identical donor characteristics except for pump time, tests of association of shorter versus longer pump time (first versus second kidney removed) by delayed graft function(DGF), slow graft function(SGF), and biopsy proven acute rejection(BPAR) were performed using McNemar's test. Freedom-from-BPAR, graft and patient survival, and renal function were also compared. Mean ± SD pump times for paired recipients with first and second kidneys were 22.7 ± 7.3 h and 31.2 ± 7.9 h, respectively (mean difference: 8.5 ± 4.5 h, P < .000001). There was no significant impact of pump time on DGF or SGF, with discordant pairs favoring less SGF with longer pump time (N.S.). The incidence of BPAR during the first 12 months post-transplant yielded a borderline difference favoring longer pump time (P = .09), and freedom-from-BPAR during the first 12 months was significantly more favorable for longer pump times (95% vs. 84%, P = 0.04). No differences were observed in graft and patient survival, and renal function. While offering significantly favorable protection from BPAR, this analysis of donor-matched recipient pairs corroborates longer MP (pump) times having no unfavorable effect on other clinical outcomes.

Randomized trial of dual antibody induction therapy with steroid avoidance in renal transplantation.

BACKGROUND: Given our previous experience using dual-induction therapy with antithymocyte globulin (ATG)/daclizumab (Dac) (each with fewer doses than if used alone), we chose to compare two distinct dual-induction strategies. METHODS: Single-center, open-label randomized trial of 200 primary kidney transplant recipients was performed: (group I, n=100) ATG/Dac (3 ATG, 2 Dac doses) versus (group II, n=100) ATG/alemtuzumab (1 dose each), with maintenance consisting of reduced tacrolimus dosing (rTd), enteric-coated mycophenolate sodium (EC-MPS), and early corticosteroid withdrawal. One half of standard EC-MPS dosing was targeted in group II to avoid severe leukopenia previously seen with alemtuzumab. The goal in both arms was to achieve rapid and effective lymphocyte depletion while simultaneously allowing reduced maintenance immunosuppression. Primary endpoint was the incidence of biopsy-proven acute rejection (BPAR). RESULTS: With median follow-up of 38 months, there were no differences in BPAR rates: 14 of 100 vs. 13 of 100 (including borderline) and 10 of 100 vs. 9 of 100 (excluding borderline) in groups I and II, respectively (nonsignificant). Actuarial patient/graft survival at 48 months was 96%/91% in group I vs. 92%/83% in group II (N.S.). Mean estimated glomerular filtration rate (±standard error) at 36 months was 72.1±3.3 vs. 67.5±3.3 in groups I and II (N.S.). Greater incidence of leukopenia occurred in group II at month 1 only (P=0.002). Percentages having EC-MPS withheld/discontinued due to leukopenia, gastrointestinal symptoms, and infection were 12 of 100, 7 of 100, and 0 of 100 in group I vs. 19 of 100, 0 of 100, and 2 of 100 in group II, respectively (P=0.01). Rates of new onset diabetes mellitus after transplantation and infections were equally low in both groups (no lymphoproliferative disorders were observed). CONCLUSIONS: These two distinct dual-induction therapies with rTd, EC-MPS, and planned early corticosteroid withdrawal resulted in favorable rates of BPAR and all secondary outcomes.

Prolonged lymphocyte depletion by single-dose rabbit anti-thymocyte globulin and alemtuzumab in kidney transplantation.

Although antibody induction has gained in popularity, two agents are rarely combined. We retrospectively analyzed peripheral lymphocyte phenotypes of renal transplant recipients who received induction therapy with a different antibody/combination: alemtuzumab(C1H), Thymoglobulin(rATG), daclizumab(Dac), rATG+C1H, and rATG+Dac. CD4+ T-cells were suppressed by C1H and rATG+C1H, as well as by rATG and rATG+Dac but to a lesser extent. The effect lasted for 3 years at around 40% of baseline values. CD8+ T-cells showed a similar trend but had a more rapid recovery to baseline. CD19+ B-cells were effectively suppressed for 2 months by C1H and rATG+C1H, and abruptly returned to baseline afterwards; suppression by rATG(7 doses) was modest but lasted longer. A higher proportion of CD56+CD16+ Natural Killer cells in C1H treated patients suggested a relatively spared effect of C1H on this cell type. Low CD25+ T-cells by 5-dose Dac returned to baseline around 6 months, whereas rATG+C1H and rATG+Dac showed persistent effect. CD4+CD25hi T-cells were suppressed by both rATG+C1H and rATG+Dac, but the initial proportion of CD4+CD25hi T-cells among CD4+ T-cells and CD4+CD25hi/CD4+CD25lo ratio were significantly higher in rATG+C1H. Overall, with extensive and persistent lymphocyte suppression by a simple administration of agents, single-dose rATG+C1H induction can be an alternative in renal transplantation.