Analysis of rabbit anti‐thymocyte globulin vs basiliximab induction in pediatric liver transplant recipients

Literature is limited comparing induction immunosuppression in pediatric liver transplant (LTx) recipients. This is a single‐center, retrospective cohort study of primary pediatric liver transplants at our center between 2005 and 2016 who received either basiliximab (BSX) or rabbit anti‐thymocyte globulin (rATG) induction. Maintenance immunosuppression consisted of tacrolimus ± a corticosteroid taper. Exclusions included receipt of an ABO‐incompatible graft, retransplantation, and multi‐organ transplantation. Primary outcomes were incidence of treated biopsy‐proven acute rejection (tBPAR) and PTLD within the first year and infections within 90 days of LTx. Secondary outcomes included graft and patient survival, time to first tBPAR, and incidence of steroid‐resistant rejection (SRR) within the first year post‐LTx. A total of 136 patients were included in the final analysis of which 57 patients (42%) received BSX induction. Patients who received rATG induction with or without a 2‐week corticosteroid taper experienced significantly more tBPAR compared to those who received BSX induction with a 6‐month corticosteroid taper (55.7% vs 33.3%, P = .01). There were no differences in the incidence of PTLD, infections, SRR, graft or patient survival, or time to first tBPAR between the two groups . Induction with rATG either with or without a short corticosteroid taper was associated with significantly more tBPAR in primary pediatric LTx recipients when compared to BSX induction with a prolonged corticosteroid taper in the setting of maintenance immunosuppression with tacrolimus.     

Alemtuzumab induction with tacrolimus monotherapy in 25 pediatric renal transplant recipients

ALA induction in transplantation has been shown to reduce the need for maintenance immunosuppression. We report the outcome of 25 pediatric renal transplants between 2007 and 2010 using ALA induction followed by tacrolimus maintenance monotherapy. Patient ages were 1–19 yr (mean 14 ± 4.1 yr). Time of follow‐up was 7–51 months (mean 26 ± 13 months). Tacrolimus monotherapy was maintained in 48% of patients, and glucocorticoids were avoided in 80% of recipients. Mean plasma creatinine and GFR at one yr post‐transplant were 0.88 ± 0.3 mg/dL and 104.4 ± 25 mL/min/1.73m², respectively. One, two, and three‐yr actuarial patient and graft survival rates were 100%. The incidence of early AR (<12 months after transplantation) was 12%, while the incidence of late AR (after 12 months) was 16%. Forty‐four percent of the recipients recovered normal, baseline renal function after an episode of AR, and 44% had persistent renal dysfunction (plasma creatinine 1.0–1.8 mg/dL). One graft was lost four yr after transplantation due to medication non‐compliance. Four (16%) patients developed BK or CMV infection. In our experience, ALA induction with tacrolimus monotherapy resulted in excellent short‐ and mid‐term patient and graft survival in low‐immunologic risk pediatric renal transplant recipients.     

Lymphocyte‐depleting induction therapy lowers the risk of acute rejection in African American pediatric kidney transplant recipients

The use of lymphocyte‐depleting induction immunosuppression has been associated with a reduction in risk of AR after KT among adult recipients, particularly among high‐risk subgroups such as AAs. However, data on induction regimen and AR risk are lacking among pediatric KT recipients. We examined outcomes among 7884 first‐time pediatric KT recipients using SRTR data (2000‐2014). Characteristics were compared across race using Wilcoxon rank‐sum tests for continuous and chi‐square tests for categorical variables. Risk of AR was estimated using modified Poisson regression, stratified by recipient race, adjusting for recipient age, gender, BMI, primary diagnosis, number of HLA mismatches, maintenance immunosuppression, and donor type. Risk of AR within 1 year was lower in AA recipients receiving lymphocyte‐depleting induction (ATG or alemtuzumab; RR, 0.66; 95% CI, 0.52‐0.83 P < .001) compared to AA recipients receiving anti‐IL‐2 receptor antibody induction. This difference was not seen in non‐AA recipients receiving lymphocyte‐depleting induction (RR, 0.93; 95% CI, 0.81‐1.06, P = .26) compared to IL‐2 induction. These findings support a role for lymphocyte‐depleting induction agents in AA pediatric patients undergoing KT and continued use of IL‐2 inhibitor induction in non‐AA pediatric KT recipients.     

Mycophenolate mofetil in pediatric renal transplantation: non-induction vs. induction with basiliximab

North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) reports have shown anti-T cell antibody, OKT3, to be deleterious in pediatric renal transplant recipients treated with mycophenolate mofetil (MMF). Unlike OKT3, basiliximab is a chimeric monoclonal antibody to the alpha subunit of the interleukin-2 receptor on activated T-lymphocytes. We sought to examine the outcome of MMF with or without basiliximab induction therapy in pediatric renal transplantation. Between January 1998, and June 2001, 49 pediatric renal transplants were performed at our center and 41 met the criteria for this study. We retrospectively analyzed the records of 25 patients who received MMF, Prednisone, CSA or TAC, alone (group I) and 16 patients who received MMF, CSA or TAC, and Prednisone in combination with basiliximab (group II). The two groups were similar with respect to recipient or donor age, gender, ethnicity, donor source (LD vs. CAD), cold ischemia time, and primary diagnosis. The basiliximab group had a shorter follow up period because of its more recent addition to our pediatric immunosuppression protocol, 12.9 +/- 5.9 months vs. 35.5 +/- 7.2 months for group I (p < 0.0001). At 6 months, the acute rejection rate was 16% (group I) compared with 25% (group II) (p = 0.689). The patient and graft survival at 6 and 12 months were 100% respectively for both groups. Basiliximab was well tolerated without significant adverse events. At 6 months, there was no significant difference between the groups in the incidence of urinary tract infection or cytomegalovirus infection. These data suggest that in the short-term, MMF with or without basiliximab induction therapy appears to yield excellent and statistically similar outcomes. However, further controlled studies are necessary to verify these findings as well as to define the role of basiliximab in MMF-treated pediatric renal transplant recipients.     

Prediction of medication non‐adherence and associated outcomes in pediatric kidney transplant recipients

Studies have continued to evaluate risk factors associated with post‐transplant non‐adherence in pediatric patients. However, many of these studies fail to evaluate how risk factors can be utilized to predict MNA. The aims of this study were to (i) determine salient risk factors associated with MNA to develop an adequate predictive risk model and (ii) assess transplant outcomes based on the presence of MNA in a large, diverse cohort of pediatric KTX recipients. One hundred and seventy‐five solitary pediatric KTX recipients transplanted from 1999 to 2013 were included. AA, males, older patients, those who lived in urban environments, had legal issues, and lived shorter distances from the transplant center were more likely to have MNA. Using logistic regression, a parsimonious model applying nine risk factors together was developed for predicting MNA, demonstrating a PPV of 69% and a NPV of 81%. Patients with MNA had more than twice the risk of biopsy proven acute rejection, 1.6 times the risk of hospitalization, and 1.8 times the risk of graft loss. Utilization of a predictive model to determine risk of MNA after pediatric KTX may offer clinicians the ability to efficiently and effectively monitor MNA following transplant.     

Effects of acute rejection vs new‐onset diabetes after transplant on transplant outcomes in pediatric kidney recipients: analysis of the Organ Procurement and Transplant Network/United Network for Organ Sharing (OPTN/UNOS) database

Improving long‐term transplant and patient survival is still an ongoing challenge in kidney transplant medicine. Our objective was to identify the subsequent risks of new‐onset diabetes after transplant (NODAT) and acute rejection (AR) in the first year post‐transplant in predicting mortality and transplant failure. A total of 4687 patients without preexisting diabetes (age 2–20 years, 2004–2010) surviving with a functioning transplant for longer than 1 year with at least one follow‐up report were identified from the OPTN/UNOS database as of September 2014. Study population was stratified into four mutually exclusive groups: Group 1, patients with a history of AR; Group 2, NODAT+; Group 3, NODAT+ AR+; and Group 4, the reference group (neither). Multivariate regression was used to analyze the relative risks for the outcomes of transplant failure and mortality. The median follow‐up time was 1827 days after 1 year post‐transplant. AR was associated with an increased risk of adjusted graft and death‐censored graft failure (HR 2.87, CI 2.48–3.33, P < .001 and HR 2.11, CI 1.81–2.47, P < .001), respectively. NODAT and AR were identified in 3.5% and 14.5% of all study patients, respectively. AR in the first year post‐transplant was a major risk factor for overall and death‐censored graft failure, but not mortality. However, NODAT was not a risk factor on graft survival or mortality.     

Incidence,risk factors,and outcomes of opportunistic infections in pediatric renal transplant recipients

OIs present significant risks to patients following solid organ transplantation. The purpose of this study was to identify risk factors for the development of OIs after kidney transplantation in pediatric patients and to evaluate the impact of OIs on outcomes in this patient population. A single‐center retrospective longitudinal cohort analysis including pediatric patients 21 yr of age or younger transplanted from July 1999 to June 2013 at an academic medical center was conducted. Patients were excluded if they received multi‐organ transplant. A total of 175 patients were included in the study. Patients who developed OIs were more likely to be female and younger at the time of transplant. A six‐factor risk model for OI development was developed. Death, disease recurrence, and PTLD development were similar between groups but trended toward increased incidence in the OI group. Incidence of rejection was significantly higher in the OI group (p = 0.04). Patients who developed OIs had several important risk factors, including younger age, EBV‐negative serostatus, CMV donor (+)/recipient (?), biopsy‐proven acute rejection, ANC <1000, MMF dose >500 mg/m², and any infection. Incidence of rejection was higher in the OI group, but rate of graft loss was not statistically different.     

Cytokine kinetics profiling in pediatric renal transplant recipients

Niederhaus SV, Bloom DD, Chang Z, Hu H, Bartosh SM, Knechtle SJ. Cytokine kinetics profiling in pediatric renal transplant recipients.
Pediatr Transplantation 2010: 14:636–645. © 2010 John Wiley & Sons A/S. Abstract: Pediatric renal transplant recipients experience side effects of immunosuppression. Few immunoassays exist which can assess the adequacy of immunosuppression. We developed a CKT, whereby cytokine levels are measured in a five‐day mixed lymphocyte reaction. We describe the in vitro cytokine responses to donor and third‐party antigen in a pilot study of nine children after living‐donor renal transplantation. The CKT identified five patterns of IFN‐γ secretion relative to donor and third‐party alloantigen: no response to alloantigen (n = 2), hypo‐response to donor (n = 3), equal response (n = 1), hyper‐response to donor (n = 1), and intermediate response (n = 2). IL‐2 and IL‐13 patterning correlated with IFN‐γ expression. Two of nine subjects had acute rejection, which correlated with intermediate and hyper‐responsive profiles. No rejection occurred during immunosuppression or donor‐specific hypo‐responsiveness. Significant immunosuppression was universal early after transplantation. Two of four children showed strong pretransplant responses to donor, which were regained three months post‐transplant, and associated with rejection in one subject. The CKT reflects the level of immunosuppression and may offer a method to assess the adequacy of immunosuppression. A pattern of complete non‐responsiveness or hypo‐responsiveness correlated with lack of acute rejection. The CKT may prove useful in titrating immunosuppression and in improving live donor selection.     

Anti-thymocyte globulin induction with delayed introduction of tacrolimus preserves renal function in pediatric liver transplant recipients

Background

Tacrolimus (TAC)-mediated renal disease occurs in up to 70% of pediatric liver transplant (LT) recipients. The safety and efficacy of renal-sparing immunosuppression using anti-thymocyte globulin (ATG) induction and delayed TAC administration has not been studied in children. We evaluated the safety and efficacy of ATG induction on preserving renal function in children within the first year (Y1) post-LT in a single-center retrospective cohort study.

Methods

Children under age 18 years of who received isolated LT from 2008 to 2020 with a GFR < 70 received renal-sparing (RS) protocol consisting of ATG with methylprednisolone (MP), delayed TAC administration, lower initial TAC trough goals, and mycophenolate mofetil (MMF). The RS group was matched 1:2 by age and LT indication with standard immunosuppression (SI) group. Changes in renal function as well as adverse events within Y1 post-LT were compared.

Results

Forty-four pediatric patients were included in the analysis, of which 13 received RS. As expected, the RS group had significantly lower mean TAC trough levels at 30 days (10.3 vs. 13.2, p = .001) post-LT. Renal function was significantly preserved at 6 (−0.26 vs. 0.21, p = .004) and 12 months (−0.33 vs. 0.11, p = .003) post-LT in the RS versus SI group as measured by mean change in serum creatinine, with similar trends observed in eGFR and cystatin C. ACR, sepsis, viremia, graft loss and mortality occurred at similar rates in both RS and SI groups.

Conclusion

Induction immunosuppression with ATG and delayed TAC administration in children with renal impairment is safe and effectively preserves renal function during Y1 post-LT.     

Bortezomib in the treatment of antibody‐mediated rejection in pediatric kidney transplant recipients: A multicenter Midwest Pediatric Nephrology Consortium study

Antibody‐mediated rejection leads to allograft loss after kidney transplantation. Bortezomib has been used in adults for the reversal of antibody‐mediated rejection; however, pediatric data are limited. This retrospective study was conducted in collaboration with the Midwest Pediatric Nephrology Consortium. Pediatric kidney transplant recipients who received bortezomib for biopsy‐proven antibody‐mediated rejection between 2008 and 2015 were included. The objective was to characterize the use of bortezomib in pediatric kidney transplant recipients. Thirty‐three patients received bortezomib for antibody‐mediated rejection at nine pediatric kidney transplant centers. Ninety percent of patients received intravenous immunoglobulin, 78% received plasmapheresis, and 78% received rituximab. After a median follow‐up of 15 months, 65% of patients had a functioning graft. The estimated glomerular filtration rate improved or stabilized in 61% and 36% of patients at 3 and 12 months post‐bortezomib, respectively. The estimated glomerular filtration rate at diagnosis significantly predicted estimated glomerular filtration rate at 12 months after adjusting for chronic histologic changes (P .001). Fifty‐six percent of patients showed an at least 25% reduction in the mean fluorescence intensity of the immune‐dominant donor‐specific antibody, 1‐3 months after the first dose of bortezomib. Non‐life‐threatening side effects were documented in 21 of 33 patients. Pediatric kidney transplant recipients tolerated bortezomib without life‐threatening side effects. Bortezomib may stabilize estimated glomerular filtration rate for 3‐6 months in pediatric kidney transplant recipients with antibody‐mediated rejection.     

Long-term results of basiliximab induction immunosuppression in pediatric liver transplant recipients

It has been shown that an induction therapy with the monoclonal anti-interleukin-2 receptor antibody basiliximab (Simulect) is capable to reduce the incidence of acute graft rejection in adult and pediatric liver transplantation (Ltx). However, data on long-term results using basiliximab in children post-Ltx are still pending. Therefore, the objective of our study was to report on the long-term results of basiliximab induction therapy in pediatric liver transplant recipients. A total of 54 children received two single doses of basiliximab in addition to cyclosporine and prednisolone following Ltx. We analyzed the incidence of acute and chronic graft rejection that of post-transplant lymphoproliferative disease (PTLD), and patient and graft survival. The follow-up was 22-46 months. The historical control group (matched controls) consisted of 54 patients treated with a cyclosporine and prednisolone dual therapy. Patient survival was 53 of 54 in the treatment group and 51 of 54 in the controls. One patient was retransplanted in the treatment group vs. three patients in the control group. The incidence of acute graft rejection was 16.6% compared with 53.7% in the control group (p < 0.001), that of chronic rejection was comparable in both groups (one of 54 vs. one of 54). The incidence of steroid resistant rejection was four of 54 vs. six of 54 that of PTLD were one of 54 vs. zero of 54. There were no adverse effects observed, which could be related to the antibody treatment. We conclude that basiliximab provides safe and effective induction immunosuppression in pediatric liver graft recipients. Short- and even long-term results are excellent.     

Continuous infusion of thymoglobulin for induction therapy in pediatric heart transplant recipients; experience and outcomes with a novel strategy for administration

Abstract:  Minimal data exist on the perioperative use of TG for induction in pediatric HTx recipients. We report our experience using continuous infusion of TG on (i) perioperative adverse events, (ii) rejection, (iii) CAV, and (iv) PTLD. TG was infused via peripheral intravenous intra- and perioperatively as a continuous infusion (24 h/day). Starting dose was 1.5 mg/kg/day titrated to achieve target lymphocyte count of 0.1–0.3 × 10⁹/L. Fifty-five patients received TG; mean age at HTx was 4.4 yr (1 day–17.8 yr). The mean duration of TG was three and a half days (2–7 days). Median platelet count during TG infusion was 95 × 10⁹/L (28–228). Five patients had TG stopped for low platelets (at 4–6 days post-HTx) – all started maintenance immunosuppression. There was no perioperative mortality due to infection. Mean follow-up of 46 survivors was 2.3 yr (0.6–5.8 yr). Fifty-one percent had ≥ ISHLT 2R rejection at a median time of 33 days post-HTx (7 days–2 yr). One patient developed PTLD 1.4 yr post-HTx; three patients developed mild-moderate CAV. TG as a continuous infusion appears to have a good safety profile. Though mild thrombocytopenia was prevalent, there was no bleeding attributable solely to TG. Whether early depletion of T-cell function will translate into long-term benefits remains to be determined.     

Role for immune monitoring to tailor induction prophylaxis in pediatric heart recipients

rATG is used for HTx induction but is costly and associated with infection and PTLD. Hypothesis: Tailoring rATG induction with CD3 monitoring results in less infection, reduced costs, and similar rejection. Retrospective review of HTx recipients receiving rATG induction. Control cases received “usual” rATG dosing (1.5 mg/kg/day typically × 5 days). Starting in October 2009, absolute CD3 monitoring (target <25 cells/mm³) guided rATG dosing (study cases). Outcomes included first‐year incidence of infection/rejection, direct costs of therapy, and incidence of PTLD/death. Study cases (n = 32) received fewer doses of rATG (median 4 vs. 5, p < 0.001) and less total rATG (median 3.2 vs. 7.4 mg/kg, p < 0.001) compared with controls (n = 17). There was no difference in incidence of infection, rejection, or patient survival during the first year post‐HTx. There was one early death in both groups and one late case of PTLD in the control group. Drug savings were significant (median drug cost per patient $2718 vs. $4756, p < 0.001). CD3‐tailored rATG induction in HTx recipients is associated with reduced drug costs and similar rates of rejection/infection. Longer follow‐up will determine whether extended benefits are associated with this induction monitoring strategy.     

Induction therapy in pediatric kidney transplant recipients discharged with a triple drug immunosuppressive regimen

Sampaio MS, Poommipanit N, Kuo H‐T, Reddy PN, Cho YW, Shah T, Bunnapradist S. Induction therapy in pediatric kidney transplant recipients discharged with a triple drug immunosuppressive regimen.
Pediatr Transplantation 2010: 14:770–778. © 2010 John Wiley & Sons A/S. Abstract: We evaluated the effectiveness of induction therapy on transplant outcomes during 2004–2007 in the United States. We retrospectively reviewed OPTN/UNOS registry and selected kidney pediatric (<21‐yr) recipients that received no induction (NoIND), IL‐2RA, or rabbit anti‐THY and were discharged with a triple drug immunosuppressive maintenance regimen, including steroids. Of 2932 recipients, 20%, 36%, and 43% were in NoIND, THY, and IL‐2RA groups, respectively. The majority received tacrolimus (88%) and MMF (89%) at discharge. There was no association of induction with the risk of acute rejection even after adjusting for known cofounders. Compared to NoIND, IL2‐RA, but not THY, had a modest decrease (3%) in absolute rate of graft loss and was associated with a risk reduction ratio of 0.51 (95% CI, 0.31–0.84) in one‐yr graft loss. At three yr, no induction agent was associated with decreased graft loss. In conclusion, induction agents were used in 80% of pediatric kidney recipients discharged with a triple drug immunosuppressive maintenance regimen between 2004–2007 in the United States. Neither THY nor IL‐2RA was associated with reduced rejection episodes. The use of induction therapy was not associated with improvement in three‐yr graft survival.     

Effects of the influenza vaccine on pediatric kidney transplant outcomes

The influenza vaccine is critical for preventing influenza‐related complications in transplant patients. Previous studies demonstrated de novo donor‐specific antibody formation and rejection following the influenza vaccination. This risk has not been adequately assessed in the pediatric population. We performed a single‐center retrospective analysis of 187 unique pediatric kidney transplant recipients, transplanted from January 1, 2006, to December 31, 2015, assessing for an association of the influenza vaccination with various transplant outcomes. The influenza vaccine was received by 125 of 187 patients within the first year post‐transplant. Using log‐rank tests and Kaplan‐Meier curves, vaccinated patients had a significantly lower risk of mortality (P = 0.048). There were no differences in death‐censored graft survival (P = 0.253), graft survival (P = 0.098), or rejection (P = 0.195) between vaccinated and unvaccinated groups. To address the problem of multiple exposures for a yearly vaccine, Cox proportional hazards regression was utilized with post‐transplant vaccination status considered as a time‐dependent covariate; analyses were performed using both a 360‐ and 180‐day vaccination period following any post‐transplant influenza vaccination. In this model, being vaccinated did not result in a significant difference in mortality (HR 0.90 [0.16, 5.15], P = 0.91), death‐censored graft survival (HR 0.70 [0.31, 1.58], P = 0.39), graft survival (HR 0.69 [0.32, 1.49], P = 0.34), or rejection (HR 0.67 [0.37, 1.19], P = 0.17). Eight patients developed de novo donor‐specific antibodies following the first post‐transplant influenza vaccination; three then developed biopsy‐proven rejection. These results suggest influenza vaccination is safe in pediatric kidney transplant recipients, and larger prospective studies are required to conclusively confirm our findings.     

Long‐term outcomes of pediatric kidney transplant recipients with a pretransplant malignancy

A childhood malignancy can rarely progress to ESRD requiring a KT. To date, few reports describe long‐term outcomes of pediatric KT recipients with a pretransplant malignancy. Between 1963 and 2015, 884 pediatric (age: 0‐17 years old) recipients received 1055 KTs at our institution. KT outcomes were analyzed in children with a pretransplant malignancy. We identified 14 patients who had a pretransplant malignancy prior to KT; the majority were <10 years old at the time of KT. Ten (71%) patients received their grafts from living donors, the majority of which were related to the recipient. Wilms' tumor was the dominant type of pretransplant malignancy, seen in 50% of patients. The other pretransplant malignancy types were EBV‐positive lymphoproliferative disorders, non‐EBV‐positive lymphoma, leukemia, neuroblastoma, soft‐tissue sarcoma, and ovarian cancer. Ten of the 14 patients received chemotherapy as part of their pretransplant malignancy treatment. Graft survival at 1, 3, and 5 years was 93%, 83%, and 72%, respectively. Patient survival at 1, 5, and 10 years was 100%, 91%, and 83%, respectively. Six (40%) patients suffered AR following KT; half of them had their first episode of AR within 1 month of KT. Our single‐center experience demonstrates that pediatric KT recipients with a previously treated pretransplant malignancy did not exhibit worse outcomes than other pediatric KT patients.     

Alemtuzumab induction in pediatric kidney transplantation

Recipient parenchymal lymphatic cells are crucial for direct and indirect pathways of allorecognition. We proposed that alemtuzumab, being infused several weeks pretransplant could eradicate peripheral lymphatic cells and promote donor‐specific tolerance. We present here a single center, retrospective review of 101 consecutive living‐donor kidney transplantations to pediatric patients aged from seven month to 18 yr, performed between September 2006 and April 2010. Immunosupression protocol included two 30 mg doses of alemtuzumab: first given 12–29 d prior to transplantation and second at the time of transplantation. Maintenance immunosupression was based on combination of low dose and wide range CNI and mycophenolate. Patients were followed for 3.8 ± 1.4 yr and protocol biopsies were taken one month, one, and three yr post transplant. The Kaplan–Meier graft and patient survival was 96% and 97% for one yr, 89% and 93% for three yr. Biopsy proven acute rejection developed in 26% patients at one yr and in 35% at two yr, no rejections occurred beyond two yr. We conclude that alemtuzumab pretreatment prior to living related donor kidney transplantation allows to reach satisfactory middle‐term results in pediatric patients with wide range and low CNI concentrations.