Successful Withdrawal Of Immunosuppression Research Articles

Defining characteristics and long-term prognosis of drug-induced autoimmune-like hepatitis: A retrospective cohort study.

Drug-induced autoimmune-like hepatitis (DI-AILH) is poorly defined and more data are required to better characterise and manage this disease entity. The aim of this study was to evaluate the clinical characteristics, histology and long-term outcomes of DI-AILH compared with idiopathic autoimmune hepatitis (AIH). This retrospective cohort study reviewed 28 DI-AILH and 39 AIH patients in a single centre. The new (2022) and simplified (2008) AIH histology criteria were used to assess DI-AILH. DI-AILH were more likely to present with jaundice (p=0.004) and higher bilirubin levels (p=0.04) than AIH. AIH patients had higher rate of immunosuppression (IS) use including second- and third-line agents, though the time to reach biochemical remission were comparable. AIH patients had more advanced fibrosis than DI-AILH (Ishak fibrosis score 3.5 vs. 1.9, p<0.0001). DI-AILH more commonly had eosinophilic aggregates (18% vs. 3%, p=0.031) and less commonly showed plasma cell aggregates (61% vs. 97%, p<0.001) than AIH. The simplified AIH histology criteria identified 1 atypical histology within the DI-AILH cohort, although this patient required long-term IS. The new AIH histology criteria classified 23 (82%) as likely AIH and 5 (18%) as possible AIH. Two of the possible DI-AILH did not require IS and one patient had successful IS withdrawal. Four DI-AILH patients with fibrosis stage ≤3 had successful IS withdrawal compared with none in the AIH group. Four patients underwent liver transplantation (LT) in both cohorts with significantly shorter time to LT in DI-AILH as the indication was for (sub)acute liver failure. Two DI-AILH patients died within 60days of LT. The new AIH histology criteria may be better at identifying DI-AILH. Immunosuppression withdrawal in those without significant fibrosis may be considered. DI-AILH is at risk of (sub)acute liver failure and early discussions with a transplant centre would be desirable.

Improved T-Cell Chimerism and Successful Withdrawal of Immunosuppression after Non-Myeloablative Stem Cell Transplantation for Sickle Cell Disease with Azathioprine/Hydroxyurea Preconditioning Added to Alemtuzumab/TBI Conditioning

Background: Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only established curative treatment option for sickle cell disease (SCD). In adult SCD patients, myeloablative conditioning is associated with significant toxicity, primarily because of cumulative organ damage. Recently, matched sibling donor (MSD) transplantation with non-myeloablative conditioning (alemtuzumab/3 Gy total body irradiation (TBI)) showed promising outcomes in adult SCD patients. This chemotherapy-free regimen, typically resulting in mixed chimerism, is associated with mild toxicity with no reports of graft-versus-host disease (GvHD). Despite mixed chimerism, the red blood cell (RBC) phenotype is completely donor-derived. However, in a large series, 13% of patients experienced graft failure. Another 8.2% of patients could not stop their immunosuppression (sirolimus) after one year, because of low donor T-cell chimerism (<50%). Reported mean donor T-cell chimerism at 12-months post-transplantation was 48% (Br J Haematol. 2021 Feb;192(4): 761-768). We hypothesized, that the addition of azathioprine and hydroxyurea as preconditioning to the alemtuzumab/TBI conditioning regimen will reduce the risk of graft failure and improve donor T-cell chimerism, enabling successful withdrawal of sirolimus in all patients. Aim: To investigate the effects of adding azathioprine/hydroxyurea preconditioning to alemtuzumab/TBI conditioning on donor chimerism levels and the occurrence of graft failure in adult SCD patients receiving non-myeloablative MSD-HSCT. Methods: Adult SCD patients with an available HLA-identical sibling donor were eligible for this treatment. All patients received three months of azathioprine 150mg qd and hydroxyurea 25mg/kg qd preconditioning. After exchange transfusion (target HbS <30%), conditioning with alemtuzumab 1mg/kg total dose and 3Gy TBI started on day -7, followed by unmanipulated peripheral hematopoietic stem cell infusion on day 0. Sirolimus as GvHD and rejection prophylaxis started on day -1. Results: Twenty SCD patients (median age 26 (range 19-49) years) were transplanted with a median follow-up of 24.5 months (range 1-52 months). Patient and transplant characteristics are shown in Table 1. Median donor myeloid and T-cell chimerism of engrafted patients was 100% (range 87-100%) and 68.5% (range 37-89%) at 12-months post-transplantation and 94% (range 86-100%) and 78.5% (range 68-88%) at 18-months post-transplantation, respectively (Figure 1). These donor T-cell chimerism percentages are higher than previously reported with alemtuzumab/TBI conditioning only. All engrafted patients had a corrected SCD phenotype with normalized hemoglobin levels. Importantly, all patients with a follow-up of ≥ 12 months (n=12) could successfully taper and stop sirolimus without decreases in donor chimerism. One year estimated disease-free survival and overall survival were 94.7%. and 93.3%, respectively. One patient (5%) experienced graft failure without autologous regeneration and subsequently died after a series of complications, including EBV reactivation, post-transplantation lymphoproliferative disease, and systemic aspergillosis. Acute gastrointestinal GvHD grade 2 occurred in one patient (5%) and resolved quickly after treatment with prednisolone. Summary/Conclusion: Azathioprine/hydroxyurea preconditioning prior to alemtuzumab/TBI resulted in improved donor T-cell chimerism, potentially reducing the risk of graft failure after non-myeloablatieve MSD transplantation in SCD patients. Importantly, all engrafted patients reached donor T-cell chimerism >50% and were able to stop immunosuppressives as scheduled. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Dose Escalation Prophylactic Donor Lymphocyte Infusion (pDLI) after T-Cell Depleted (TCD) Matched Related Donor (MRD) Allogeneic Hematopoietic Cell Transplantation (Allo-HCT) Is Feasible and Results in Higher Donor Chimerism, Faster Immune Re-Constitution and Prolonged PFS

Background:Alemtuzumab based TCD allografts allow low rates of acute and chronic GVHD. However, delayed immune reconstitution and mixed donor chimerism (MDC) may increase infection rates, if not relapse. We conducted a prospective trial exploring the feasibility of early withdrawal of immunosuppression (WOI) followed by dose-escalation pDLI after alemtuzumab-based TCD conditioning for patients (pts) with high-risk hematologic diseases.Methods:High-risk hematologic malignancies were eligible if planned for matched related or matched unrelated donor TCD allografts and tacrolimus for GVHD prophylaxis. Patients began WOI as early as day 60 if no GVHD or relapse, followed by escalated doses of pDLI every 4-8 weeks for up to 5 treatments starting at 2x105 CD3/kg for MRD and 1x105 for MUD with half-log dose escalation. The primary aim was for over 50% of patients to receive at least one DLI.Results:75 patients (pts) thus far have been enrolled. A planned interim analysis of 59 pts demonstrated that very few MUD allografts were evaluable since it was not possible to achieve WOI and at least one DLI; thus, MRD grafts were primarily enrolled thereafter. In total, 46 pts (61%) received MRD. 37 pts (49.3%) had AML, including 16 (42%) not in remission. Pts received fludarabine/melphalan (n=47), flu/busulfan (n=26), or TBI/etoposide (n=2) with alemtuzumab 30-100mg.40 pts (53%) did not undergo WOI due to acute GVHD (n=16), relapse (n=9), death (n=8), too early for WOI (n=2), poor graft function (n=2) or were enrolled to another study (n=3), and 5 (6.6%) underwent WOI but did not receive pDLI due to acute GVHD (n=4), death (n=1). Successful WOI and receipt of at least one pDLI was achieved in 30 (39.5%) pts, with 4, 9, 5, 5, and 7 pts receiving 1, 2, 3, 4 and 5 total pDLI, respectively. 61.9% (26/42) of MRD patients could undergo WOI and at least one pDLI versus only 14.2% (4/28) of MUD patients. Median time from transplant to first pDLI was 97 days (range 84 to 164). After pDLI, 11 pts developed grade I-IV aGVHD. Rates of aGVHD, grades II-V at 1 year post-HCT were 47% for all pts versus 27.5% for those receiving at least one pDLI. One year NRM rate was 16.7% in all pts and 3.5% in pDLI pts. Median PFS and OS for all pts were 322 days and 644 days, respectively. The median PFS and OS for those receiving at least one pDLI were not reached. 2 year PFS and OS for all the patients were 36.8% and 45.3% compared to 52.5% and 60.7% for patients who received at least one pDLI. At one year, among pts receiving at least one pDLI , 95% of evaluable pts (20/21) had full donor chimerism compared to 59% (10/17) of those not receiving any pDLI. There was also a clear increment in chimerism with each pDLI. Pts receiving pDLI had faster lymphocyte count recovery and higher IgG levels at one year post allo-SCT. Minimal residual disease was monitored by WT1 qRT-PCR in 16 AML/MDS pts who received pDLI; 11/16 (69%) pts had WT1 transcript decrease, which suggests a better outcome for those treated with pDLI. TCR sequencing was done in 8 pts who received between 2-5 pDLI to assess if pDLI could change T cell clonality, resulting in enrichment of possible leukemia-antigen associated T cell proliferation, TCR sequencing using peripheral blood revealed reduction in the TCR diversity and clonal enrichment of T cells. Direct comparison of the outcomes between our historical control pts and the pts treated with pDLI having the same disease risk index (DRI) is ongoing with the hope to provide more definitive PFS benefit using early WOI and pDLI.Conclusions:This prospective trial demonstrates that early WOI followed by dose-escalation pDLI is feasible after alemtuzumab based regimens for matched related donors and may suggest favorable results mediated by improved donor chimerism. For matched unrelated donors, WOI should occur later and/or pDLI given prior to tapering immune suppression. DisclosuresPark:OncoTherapy Science, Inc.: Consultancy. Stock:Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees. Larson:Amgen Inc.: Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Astellas: Consultancy, Research Funding. Odenike:Jazz: Membership on an entity's Board of Directors or advisory committees; CTI/Baxalta: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria; Celgene: Membership on an entity's Board of Directors or advisory committees. Riedell:Kite Pharma: Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees. Liu:BMS: Research Funding; Karyopharm: Research Funding.

Strategies for Liver Transplantation Tolerance.

Liver transplant (LT) recipients require life-long immunosuppression (IS) therapy to preserve allograft function. The risks of chronic IS include an increased frequency of malignancy, infection, renal impairment, and other systemic toxicities. Despite advances in IS, long-term LT outcomes have not been improved over the past three decades. Standard-of-care (SoC) therapy can, in rare cases, lead to development of operational tolerance that permits safe withdrawal of maintenance IS. However, successful IS withdrawal cannot be reliably predicted and, in current prospective studies, is attempted several years after the transplant procedure, after considerable exposure to the cumulative burden of maintenance therapy. A recent pilot clinical trial in liver tolerance induction demonstrated that peri-transplant immunomodulation, using a regulatory T-cell (Treg) approach, can reduce donor-specific alloreactivity and allow early IS withdrawal. Herein we review protocols for active tolerance induction in liver transplantation, with a focus on identifying tolerogenic cell populations, as well as barriers to tolerance. In addition, we propose the use of novel IS agents to promote immunomodulatory mechanisms favoring tolerance. With numerous IS withdrawal trials underway, improved monitoring and use of novel immunomodulatory strategies will help provide the necessary knowledge to establish an active liver tolerance induction protocol for widespread use.

Involvement of PDL1 and Foxp3 Expression in Human Liver Transplantation Tolerance

Background: Operational tolerance after liver transplantation (LT) characterized by successful immunosuppression withdrawal (ISW) without rejection has been reported but its underlying mechanisms are unknown. Programmed cell death protein 1 (PD-1)/its ligand PD-L1 pathway, concomitant with forkhead box protein P3 (Foxp3), may play a specific role in operational tolerance after LT. Methods: Tolerance and control recipients are defined as recipients maintained without and with standard dose of immunosuppression (IS) without episodes of rejection for at least one year. Liver biopsies from 38 tolerant, 35 non-tolerant (including 16 samples that triggered reintroduction of IS and 19 samples after IS reintroduction) and 38 control LT patients were studied. Expression of PD-1, PD-L1, Foxp3, CD4 and CD8 were determined by immunohistochemical staining. Results: PD-1 was hardly detectable while PD-L1 was expressed in the cytoplasm of hepatocytes and Foxp3 was localized in the nucleus. CD4 and CD8 were expressed in the periportal area. Tolerant and control patients exhibited a higher PD-L1 level (median[interquartile]: 20.8[16.2-26] relative units (RU) and 19.8[11.2-30.8]RU vs. 13.3[8-19.3]RU; p=0.0008 and p=0.0036) and higher Foxp3/CD8 ratio (4[0.8-11.8] and 3[1-11.8] vs. 0[0-2.5]; p=0.0001 and p=0.0013) in compared to non-tolerant patients at the moment of triggering IS reintroduction; whereas CD4 expression was comparable between the three groups. A weak but significant correlation between PDL1 and Foxp3 was identified (r=0.2401, p=0.0211). Conclusion: PD-L1 and Foxp3 might concomitantly contribute to the regulation of immune-tolerant in LT patients. Further studies regarding PD-1/PD-L1 pathway may shed light on the mechanisms for operational tolerance after LT.

Chimerism and Tolerance Without GVHD in Mismatched Recipients of Combined Hematopoietic Stem Cell/Kidney Transplants: Donor-Specific Hyporeactivity Is Not a Reliable Biomarker for Tolerance.

We recently reported low-intensity conditioning combined with facilitating cell (FC)-enriched hematopoietic stem cell transplantation (FCRx) can safely achieve high levels of durable chimerism in unrelated and related mismatched kidney transplant (KTx) recipients. This is associated with stable renal function, absence of GVHD, and successful withdrawal of immunosuppression (IS). We herein present interim follow-up on 19 subjects and present data to demonstrate that donor specific hypoactivity does not correlate with tolerance to the renal allograft if durable chimerism is not present. HLA-mismatched related (n = 12) and unrelated (n = 7) living donor KTx recipients were conditioned with fludarabine (days -5,-4,-3), cyclophosphamide (50 mg/kg day -3, +3), 200 cGy TBI, (day -1), KTx (day 0), followed by infusion of cryopreserved G-CSF mobilized FCRx (day +1). Multilineage chimerism was assessed by STR analysis. Mixed lymphocyte reaction (MLR) assays were performed to assess donor-specific hyporeactivity. 18 of 19 patients demonstrated peripheral blood macrochimerism at 1 month post-transplant (6% - 100%). The one patient who failed to engraft was highly sensitized (Class I PRA > 40%). No subjects developed GVHD or “engraftment syndrome.” Durable whole blood and T cell chimerism was achieved in 12 subjects. All patients demonstrated in vitro donor-specific hyporesponsiveness (DSH) by MLR +/- CML post-transplant regardless of chimerism status. However, DSH in patients who lost chimerism was not predictive of successful IS weaning, as 3 transiently chimeric patients with DSH had subclinical Banff 1A rejection on protocol biopsy while on IS monotherapy. Recurrence of underlying autoimmune disease has only occurred in subjects who were transiently chimeric. Protocol biopsies in chimeric subjects have exhibited normal histology for up to 3 years. 12 chimeric subjects are completely off IS from 3-42 months. The presence of durable, high level whole blood and T cell chimerism in combined kidney + FCRx recipients is a robust biomarker of tolerance. DSH without donor chimerism does not predict successful IS withdrawal or tolerance. DISCLOSURES:Gallon, L.: Grant/Research Support, NOvartis. Tollerud, D.: Other, regenerex LLC, COO. Elliot, M.: Employee, REGENEREX LLC. Ildstad, S.: Other, regenerex LLC, CEO.

Chimerism and Tolerance Without Gvhd In Mismatched Recipients Of Combined Hematopoietic Stem Cell/Kidney Transplants: Donor-Specific Hyporeactivity Is Not a Reliable Biomarker For Tolerance

We recently reported that low-intensity conditioning combined with facilitating cell (FC)-enriched hematopoietic stem cell transplantation (FCRx) can safely achieve high levels of durable chimerism in unrelated and related mismatched kidney transplant (KTx) recipients. This is associated with stable renal function, complete absence of GHVD, and successful withdrawal of immunosuppression (IS). We herein present interim follow-up of now 19 subjects and present data to demonstrate that donor specific hypoactivity does not correlate with tolerance to the renal allograft if chimerism is not present.HLA-mismatched related (n = 12) and unrelated (n = 8) living donor KTx recipients were conditioned with fludarabine (days -5,-4,-3), cyclophosphamide (50 mg/kg day -3, +3), 200 cGy TBI, (day -1), KTx (day 0), followed by infusion of cryopreserved G-CSF mobilized FCRx (day +1). Multilineage chimerism was assessed prospectively by STR analysis. Mixed lymphocyte reaction (MLR) and cell mediated lympholysis (CML) assays were performed to assess donor-specific hyporeactivity.Subjects ranged in age from 18-65 years. 18 of 19 patients demonstrated peripheral blood macrochimerism at 1 month post-transplant (6% - 100%). The one patient who failed to engraft was highly sensitized (Class I PRA > 40%). No subjects developed acute or chronic GVHD or “engraftment syndrome.” Chimerism was transient in 4 subjects, each of which received either a suboptimal cell dose or had PRA > 20%. Durable whole blood and T cell chimerism was achieved in 14 subjects. All patients demonstrated in vitro donor-specific hyporesponsiveness (DSH) by MLR +/- CML post-transplant regardless of chimerism status. However, DSH in patients who lost chimerism was not predictive of successful IS weaning, as 3 of 4 transiently chimeric patients with DSH had subclinical Banff 1A rejection on protocol biopsy and while on tacrolimus monotherapy. Recurrence of underlying autoimmune disease has only occurred in subjects who were transiently chimeric. Protocol biopsies in chimeric subjects have exhibited normal histology for up to 3 years. Nine chimeric subjects are completely off IS from 1-34 months. The remainder are in the process of weaning.The presence of durable, high level whole blood and T cell chimerism in combined kidney + FCRx recipients is a robust biomarker of tolerance. DSH alone without donor chimerism in the first post-transplant year does not predict successful IS withdrawal or tolerance. Disclosures:Tollerud:Regenerex, LLC: Equity Ownership. Ildstad:Regenerex, LLC: Equity Ownership.

Long Term Follow Up of 30 Operationally Tolerant Liver Transplant Recipients

Introduction: The advances of immunosuppression and post-operative follow up have contributed to an improvement of the long term survival of liver transplant recipients. However, complications related to long term immunosuppression affect both long term survival and quality of life of these patients. Successful withdrawal of immunosuppression has been achieved in many liver transplant recipients. In this study we present a long term follow up of a cohort of patients that had their immunosuppression successfully withdrawn. Methods: We studied the outcome of liver transplant patients who had their immunosuppression successfully withdrawn. A total of thirty operationally tolerant patients were studied (27 men and 3 women). Twenty three of them were weaned off immunosuppression during a withdrawal study that took place about 10 years ago. The remaining seven patients were part of a cohort of patients that were transplanted more recently under Campath-1H induction immunosuppression and were weaned during the last 5 years. Results:Patient Survival:Patient, graft survival: With a follow up until end of January 2012, the post-transplant follow up of the patients was from 7-20 years (average:14.15) and the off immunosuppression follow up was from 1.4-11 years, (average:7.25). There were seven mortalities. Deaths were due to cardiovascular causes (n=5): [myocardial infarct (n=3), cerebrovascular accident (n=1), pulmonary embolism (n=1)]. Other mortalities included biliary obstruction-sepsis (n=1), chronic rejection-sepsis (n=1). Average age of these patients at the time of death was 69.01 years. There were no re-transplants during this period of time. Rejection episodes: A patient presented a moderate rejection 5.3 years after immunosuppression withdrawal and was put back on maintenance immunosuppression. Renal function: Until the end of the follow up period, a patient was on dialysis and another received a kidney transplant 13.9 and 19.26 years post-transplantation respectively. Neoplasms: Six patients presented with squamous cell skin cancer (n=2), throat, kidney, lung cancer and melanoma (one each). Conclusions: Operational tolerance after liver transplantation can be achieved for a long period of time, however is not a permanent state and continuous vigilance and follow up is required to detect rejection episodes.

Operational tolerance after liver transplantation

The achievement of an immunosuppression (IS)-free state after transplantation represents the ultimate goal of any immunosuppressive regimen. While clinical operational tolerance (COT) remains the exception after other types of solid organ transplantation, several cases of COT have been described after liver transplantation (LT). Overall, the experience gained so far worldwide demonstrates that COT can be achieved safely in one quarter of selected individuals, irrespective of the immunological background of donor and recipient, patient age, indication for LT, study endpoint, length of the weaning period and of pre/post-weaning follow-up, presence or not of chimerism. However, most transplant physicians still believe that the achievement of COT is still out of reach for the majority of LT recipients because of the potential risk for transplant survival, the non-randomized nature of most of the studies reported so far, and the selective nature of the patients enrolled in such studies, making them non-representative of the whole population of LT recipients. Despite these concerns, the present article demonstrates that this attitude is potentially no longer justified, given the growing evidence that a permanent and stable IS-free state can be achieved in a proportion of individuals who have received a LT for non-immune mediated liver diseases.

Graft fibrosis in stable pediatric liver transplant recipients: What does it mean?

Graft fibrosis in stable pediatric liver transplant recipients: What does it mean?

Dendritic Cell Subset Ratio in Peripheral Blood Correlates with Successful Withdrawal of Immunosuppression in Liver Transplant Patients

Human dendritic cell (DC) subsets appear to play distinct roles in the induction and regulation of immune responses. While monocytoid DC (DC1) induce T-helper (Th) 1-type responses, plasmacytoid DC (DC2) have been reported to selectively induce Th2 responses. In blood, their precursors (p) can be identified as HLA-DR+ lineage- cells that are further characterized as CD11c+ CD123-/lo (IL-3Ralpha-/lo) (pDC1) or as CD11c- CD123hi (pDC2) by rare event, flow cytometric analysis. We compared the incidences of pDC1 and pDC2 in peripheral blood mononuclear cell populations isolated from normal healthy controls and from 3 groups of clinically stable liver transplant patients. Group A had been successfully withdrawn from immunosuppression, whereas group B were undergoing prospective drug weaning and on minimal anti-rejection therapy. In group C, drug withdrawal had either failed or never been attempted and patients were on maintenance immunosuppression. Assessment of DC subsets and the pDC2 : pDC1 ratio showed good intra-and interassay reproducibility. Compared with patients in group C, those in groups A and B demonstrated a significantly higher relative incidence of pDC2 and a lower incidence of pDC1 - similar to those values observed in normal healthy controls. Moreover, the pDC2 : pDC1 ratio was significantly higher in patients undergoing (successful) weaning and in those off immunosuppression compared with patients on maintenance immunosuppression.

Defining the outcome of immunosuppression withdrawal after liver transplantation.

Successful immunosuppression withdrawal should benefit the natural history of organ transplantation patients. To identify the clinical hazards of removing drug treatment and possible characteristics that predict a favorable outcome in long-term liver recipients, immunosuppression was withdrawn completely and the clinicopathological outcome documented in 18 liver recipients. Indication for transplantation, HLA matching, early rejection history, and presence of microchimerism were examined as predictors of outcome. Chimerism was determined by polymerase chain reaction-based examination for donor-specific HLA-DRB1 alleles and Y-gene-specific nucleotide sequences. At 3 years, 5 patients (28%) remained completely off immunosuppression; 12 patients (67%) experienced histological graft changes: acute rejection in 4, portal tract inflammation/hepatitis in 7, and necrosis in 1. Hepatitis B or C viral infections did not account for the nonrejection patterns. Unmasking of systemic disorders occurred. Chimerism, demonstrated in 7 patients (39%), with skin the optimal tissue, was not associated with tolerance. Parameters associated with successful drug withdrawal were transplantation for non-immune-mediated liver disorders, fewer donor-recipient HLA A, B, and DR mismatches, and a low incidence of early rejection. Immunosuppression withdrawal is a feasible option in a proportion of selected liver recipients, but identification of tolerant patients remains imprecise.