Withdrawal Of Immunosuppression Research Articles

Clinical parameters and biomarkers predicting spontaneous operational tolerance after liver transplantation: A scoping review

Indefinite allograft acceptance after immunosuppression withdrawal (ISW), also known as operational tolerance (OT), can occur spontaneously after liver transplantation (LT), but reliable and reproducible prognosis of OT versus non-OT outcomes remains elusive. To prime this, systematic extraction of OT-predictive factors from the literature is crucial. We provide the first comprehensive identification and synthesis of clinical parameters and biomarkers predicting spontaneous OT in non-autoimmune/non-replicative viral LT recipients selected for ISW. We searched Embase, Medline, the Cochrane Central Register of Controlled Trials, clinicaltrials.gov, and the World Health Organization International Clinical Trials Registry Platform for articles, conference abstracts, and ongoing trials. We contacted principal investigators of stand-alone abstracts and ongoing trials for unpublished data and screened citations and references of eligible articles. Twenty-three articles reporting on 11 completed ISW studies, 13 abstracts, and five trial registry entries were included. Longer time between LT and ISW was the only clinical parameter that may increase the incidence of OT. Prognostic biomarkers conspicuously differed between pediatric and adult ISW candidates. These included allograft gene expression patterns and peripheral blood immune exhaustion markers for adults, and histological allograft scores for children. Our results will foster cross-validation efforts to facilitate safe and harmonized candidate selection for successful ISW.

Dysfunctional Immune Regulation in Autoimmune Hepatitis: From Pathogenesis to Novel Therapies.

Autoimmune hepatitis (AIH) is a chronic inflammatory disorder characterized by hypergammaglobulinemia, presence of serum autoantibodies and histological features of interface hepatitis. AIH therapeutic management still relies on the administration of corticosteroids, azathioprine and other immunosuppressants like calcineurin inhibitors and mycophenolate mofetil. Withdrawal of immunosuppression often results in disease relapse, and, in some cases, therapy is ineffective or associated with serious side effects. Understanding the mechanisms underlying AIH pathogenesis is therefore of paramount importance to develop more effective and well tolerated agents capable of restoring immunotolerance to liver autoantigens. Imbalance between effector and regulatory cells permits liver damage perpetuation and progression in AIH. Impaired expression and regulation of CD39, an ectoenzyme key to immunotolerance maintenance, have been reported in Tregs and effector Th17-cells derived from AIH patients. Interference with these altered immunoregulatory pathways may open new therapeutic avenues that, in addition to limiting aberrant inflammatory responses, would also reconstitute immune homeostasis. In this review, we highlight the most recent findings in AIH immunopathogenesis and discuss how these could inform and direct the development of novel therapeutic tools.

Prolonged immunosuppression does not improve risk of sensitization or likelihood of retransplantation after kidney transplant graft failure.

The optimum approach towards immunosuppression withdrawal following kidney transplant failure is unclear. Prolonged weaning may be associated with reduced sensitization, less graft nephrectomy and greater likelihood of retransplantation, but conversely increased risk of infection, malignancy and death. We conducted a single-centre retrospective analysis of patients experiencing graft failure between 2007 and 2017, comparing rates of sensitization, retransplantation, nephrectomy, infection, malignancy and death between patients who had immunosuppression weaned over <90 vs. 90-180 vs. >180 days. Patient survival after immunosuppression withdrawal over <90 vs. 90-180 vs. >180 days was 73.3%, 72.1% and 80.4%, respectively (P = 0.35), with no differences in cPRA (80.06 vs. 81.21 vs. 85.42, P = 0.66) or retransplantation rate [24/31 (77.4%) vs. 21/35 (60.0%) vs. 22/36 (61.1%), P = 0.13]. There was significantly less nephrectomy after late immunosuppression cessation [10/42 (23.8%) vs. 7/42 (16.7%) vs. 3/43 (7.0%), P = 0.01] but no differences in infections or malignancy. On competing risk regression (death as competing risk) controlling for cofactors including age, nephrectomy and rejection, prolonged immunosuppression did not predict likelihood of retransplantation (SHR 1.000, P = 0.88). Prolonged immunosuppression withdrawal does not reduce sensitization or improve retransplantation rates but is associated with less nephrectomy. Immunosuppression withdrawal should be tailored to individual circumstances after graft failure.

CyTOF-Enabled Analysis Identifies Class-Switched B Cells as the Main Lymphocyte Subset Associated With Disease Relapse in Children With Idiopathic Nephrotic Syndrome.

B cell depleting therapies permit immunosuppressive drug withdrawal and maintain remission in patients with frequently relapsing nephrotic syndrome (FRNS) or steroid–dependent nephrotic syndrome (SDNS), but lack of biomarkers for treatment failure. Post-depletion immune cell reconstitution may identify relapsing patients, but previous characterizations suffered from methodological limitations of flow cytometry. Time-of-flight mass cytometry (CyTOF) is a comprehensive analytic modality that simultaneously quantifies over 40 cellular markers. Herein, we report CyTOF-enabled immune cell comparisons over a 12-month period from 30 children with SDNS receiving B cell depleting therapy who either relapsed (n = 17) or remained stable (n = 13). Anti-CD20 treatment depleted all B cells subsets and CD20 depleting agent choice (rituximab vs ofatumumab) did not affect B cell subset recovery. Despite equal total numbers of B cells, 5 subsets of B cells were significantly higher in relapsing individuals; all identified subsets of B cells were class-switched. T cell subsets (including T follicular helper cells and regulatory T cells) and other major immune compartments were largely unaffected by B cell depletion, and similar between relapsing and stable children. In conclusion, CyTOF analysis of immune cells from anti-CD20 antibody treated patients identifies class-switched B cells as the main subset whose expansion associates with disease relapse. Our findings set the basis for future studies exploring how identified subsets can be used to monitor treatment response and improve our understanding of the pathogenesis of the disease.

Tolerance and minimization of immunosuppressive therapy after liver transplantation

In this review of current publications, we look at the molecular mechanisms of tolerance of the liver and its allografts in terms of minimization and possibilities of withdrawing immunosuppressive therapy, mainly in the long-term period after liver transplantation. Information about clinical trials with regulatory T cells (Tregs) for the purpose of tolerance induction is presented. Data from a new consensus study on individualization of immunosuppressive therapy regimens are presented. Options for possible withdrawal of immunosuppression both in the early and in the long term after liver transplantation (LT) are considered. We suggest a way to study the lymphoproliferative potential of a liver transplant recipient to be investigated, since not only rejection determines life expectancy, but also the degree of immunosuppression effect on bone marrow depending on patient age.

Clinical Presentation and Management of Coronavirus Disease 2019 in Renal Allograft Recipients: A Case Series

: Complications of coronavirus disease 2019 infection in renal transplant recipients are associated with significant morbidity and mortality and the existence of co-morbidities are more likely to develop serious illness. In this case series the clinical outcomes of coronavirus disease 2019 in 6 recipients tested positive is explained. D-dimer, ferritin and C-reactive protein values are elevated in all cases. The patients were on immunosuppressant therapy and had stable graft function before coronavirus disease 2019 infection. After the diagnosis, management included reduction and withdrawal of immunosuppression and significant changes in corticosteroids. One of our patients showed significant improvement without dosage adjustment of immunosuppressant.Key words: Severe acute respiratory syndrome coronavirus 2, Rapid antigen test, Mycophenolate mofetil, Tacrolimus, Intravenous immunoglobulin.

Advances in Liver Transplantation: where are we in the pursuit of transplantation tolerance?

Liver transplantation is the ultimate treatment option for end-stage liver disease. Breakthroughs in surgical practice and immunosuppression have seen considerable advancements in survival after transplantation. However, the intricate management of immunosuppressive regimens, balancing desired immunological quiescence while minimizing toxicity has proven challenging. Diminishing improvements in long-term morbidity and mortality have been inextricably linked with the protracted use of these medications. As such, there is now enormous interest to devise protocols that will allow us to minimize or completely withdraw immunosuppressants after transplantation. Immunosuppression withdrawal trials have proved the reality of tolerance following liver transplantation, however, without intervention will only occur after several years at the risk of potential cumulative immunosuppression-related morbidity. Focus has now been directed at accelerating this phenomenon through tolerance-inducing strategies. In this regard, efforts have seen the use of regulatory cell immunotherapy. Here we focus particularly on regulatory T cells, discussing preclinical data that propagated several clinical trials of adoptive cell therapy in liver transplantation. Furthermore, we describe efforts to further optimize the specificity and survival of regulatory cell therapy guided by concurrent immunomonitoring studies and the development of novel technologies including chimeric antigen receptors and co-administration of low-dose IL-2.

O-24 A CASE SERIES OF CHLOROQUINE MONOTHERAPY TO INDUCE BIOCHEMICAL REMISSION IN PATIENTS WITH RELAPSED AUTOIMMUNE HEPATITIS

Azathioprine (AZA) and prednisone (PD) are the standard treatment (ST) for the onset or relapse of autoimmune hepatitis (AIH). Antimalarials were effective for maintenance of remission of AIH after immunosuppression withdrawal. Our aim is to describe a series of patients who relapsed after antimalarial withdrawal and achieved biochemical remission after reintroduction of chloroquine in monotherapy. Eight patients received chloroquine diphosphate (DCQ) 250mg/d or hydroxichloroquine (HCQ) 400-800mg/d in monotherapy for biochemical remission after relapse. The schedule is described below: histological remission (HR) with ST → ST withdrawal and antimalarial use for maintenance of remission for 1-3y → antimalarial withdrawal → relapse of AIH → reintroduction of antimalarial instead of ST, at the request of patient due to corticosteroids side effects (SE). Four out of 8 patients underwent liver biopsy to evaluate HR after at least 18mo of biochemical remission. Mean age at diagnosis of AIH of 36.2 ± 20.4y; 6 type-1, 2 anti-SLA/LP (5 reactive in 7 tested); 3 with cirrhosis at diagnosis. Mean doses of AZA/PD at HR were, respectively, 84.4 ± 18.6 and 9.4 ± 2.2mg/d. Mean interval between antimalarial withdrawal and relapse was 20.5 ± 34.1mo. Mean ALT at relapse was 139.7 ± 54.2 U/L. Three patients received DCQ and 5 HCQ. During HCQ intake 1 patient needed further adjustment of drug to 800 mg/d for 15 days due to worsening of ALT from 130 to 246 U/L, with subsequent reduction to the initial dose. Seven patients achieved biochemical remission, in a mean time of 14.2 ± 19.9mo; 3/4 had histological remission. The drug was well tolerated and there were no serious SE. CQ monotherapy was safe and effective for induction of remission in this subgroup of AIH. This finding raises arguments to include this drug as an option for treatment of AIH, not necessarily in monotherapy.

Effectiveness of various treatment strategies in COVID-19 patients having Solid Organ Transplant: A Systematic Review

Introduction: This narrative review provides an evidence-based summary of the various interventions in the management of Post Solid organ transplant patients who reported positive for COVID-19. &#x0D; Materials and Methods: For this systematic review, observational and experimental studies; conducted on Post- Organ transplant patients, either symptomatic or asymptomatic, who tested positive for COVID-19 were included. Only solid organ transplant patient studies were considered standard for this review type. The English version, both published and unpublished articles, from Dec 2019 to Aug 2020, were evaluated using Pubmed, Google Scholar, Science direct, Medrixv search engines. The articles with incomplete details about a transplant or covid management were excluded.&#x0D; Results: We selected 43 articles out of which 9 were retrospective studies, 2 were cohort studies, one was an experimental study, and 31 were case studies. According to the literature review, effective management therapy includes the withdrawal of immunosuppressive drugs, increase/ constant steroid dose, and regimen containing HCQ, interleukin inhibitor, and one antiviral drug especially remdesivir proved to be the most effective among all. In others, administration of IV immunoglobulins/convalescent plasma therapy proved effective in various trials but related data is currently limited. While Lop/Rit, Interferons alpha, and oseltamivir trials are also given; these therapies didn’t prove to be much effective individually.&#x0D; Conclusion: More trials are required to find the effectiveness of Convalescent plasma therapy. It can be proved as an effective treatment in critical patients. IV immunoglobulins effectiveness should also be tested in critical patients and for this more experimental trials are needed.

Development of immunosuppressive myeloid cells to induce tolerance in solid organ and hematopoietic cell transplant recipients

Replacement of failed organs followed by safe withdrawal of immunosuppressive drugs has long been the goal of organ transplantation. We studied changes in the balance of T cells and myeloid cells in the blood of HLA-matched and -mismatched patients given living donor kidney transplants followed by total lymphoid irradiation, anti-thymocyte globulin conditioning, and donor hematopoietic cell transplant to induce mixed chimerism and immune tolerance. The clinical trials were based on a conditioning regimen used to establish mixed chimerism and tolerance in mice. In preclinical murine studies, there was a profound depletion of T cells and an increase in immunosuppressive polymorphonuclear (pmn) myeloid-derived suppressor cells (MDSCs) in the spleen and blood following transplant. Selective depletion of pmn MDSCs in mice abrogated mixed chimerism and tolerance. In our clinical trials, patients given an analogous tolerance conditioning regimen developed similar changes, including profound depletion of T cells and a marked increase in MDSCs in blood posttransplant. Posttransplant pmn MDSCs transiently increased expression of lectin-type oxidized LDL receptor-1, a marker of immunosuppression, and production of the T-cell inhibitor arginase-1. These posttransplant pmn MDSCs suppressed the activation, proliferation, and inflammatory cytokine secretion of autologous T-cell receptor microbead-stimulated pretransplant T cells when cocultured invitro. In conclusion, we elucidated changes in receptors and function of immunosuppressive myeloid cells in patients enrolled in the tolerance protocol that were nearly identical to those of MDSCs required for tolerance in mice. These trials were registered at www.clinicaltrials.gov as #NCT00319657 and #NCT01165762.

Non-invasive alloimmune risk stratification of long-term liver transplant recipients

Management of long-term immunosuppression following liver transplantation (LT) remains empirical. Surveillance liver biopsies in combination with transcriptional profiling could overcome this challenge by identifying recipients with active alloimmune-mediated liver damage despite normal liver tests, but this approach lacks applicability. Our aim was to investigate the utility of non-invasive tools for the stratification of stable long-term survivors of LT, according to their immunological risk and need for immunosuppression. We conducted a cross-sectional multicentre study of 190 adult LT recipients assessed to determine their eligibility to participate in an immunosuppression withdrawal trial. Patients had stable liver allograft function and had been transplanted for non-autoimmune non-replicative viral liver disease >3 years before inclusion. We performed histological, immunogenetic and serological studies and measured the intrahepatic transcript levels of an 11-gene classifier highly specific for T cell-mediated rejection (TCMR). In this cohort, 35.8% of patients harboured clinically silent fibro-inflammatory liver lesions (13.7% had mild damage and 22.1% had moderate-to-severe damage). The severity of liver allograft damage was positively associated with TCMR-related transcripts, class II donor-specific antibodies (DSAs), ALT, AST, and liver stiffness measurement (LSM), and negatively correlated with serum creatinine and tacrolimus trough levels. Liver biopsies were stratified according to their TCMR transcript levels using a cut-off derived from biopsies with clinically significant TCMR. Two multivariable prediction models, integrating ALT+LSM or ALT+class II DSAs, had a high discriminative capacity for classifying patients with or without alloimmune damage. The latter model performed well in an independent cohort of 156 liver biopsies obtained from paediatric liver recipients with similar inclusion/exclusion criteria. ALT, class II DSAs and LSM are valuable tools to non-invasively identify stable LT recipients without significant underlying alloimmunity who could benefit from minimisation of immunosuppression. A large proportion of liver transplant patients with normal liver tests have inflammatory liver lesions, which in 17% of cases are molecularly indistinguishable from those seen at the time of rejection. ALT, class II donor-specific antibodies and liver stiffness are useful in identifying patients with this form of subclinical rejection. We propose these markers as a useful tool to help clinicians determine if the immunosuppression administered is adequate.

Predicting lupus low disease activity state and remission in SLE: novel insights

ABSTRACT Introduction:Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with extreme heterogeneity, which sometimes may be life-threatening. Principles of treat to target (T2T) in SLE were put forward more recently, leading to better long-term survival and reduced damage accrual. Areas covered: Lupus low disease activity state (LLDAS) and remission are currently the most widely accepted principal goals of SLE-T2T recommendations. In this article, we will deliver the novel insights into the definitions of LLDAS/remission, attainability, and, most importantly, clinical predictors of LLDAS and remission in SLE. Expert opinion: Since the release of the LLDAS and the framework on definitions of remission in SLE, there has been much evidence of a correlation between target attainment or maintenance and better prognosis. In the meantime, researchers are searching for predictors of target attainment. Noteworthy, prospective randomized trials are lacking worldwide to verify the benefits of T2T in various aspects of SLE. The most essential issue is that the optimal definition of the therapeutic target for SLE remains controversial, particularly regarding the maintenance dose of prednisone, the need for immunosuppressive withdrawal, and the requirement for serologic conversion. How to implement T2T principles in clinical practice also needs further investigation.

Leishmaniasis: A new method for confirming cure and detecting asymptomatic infection in patients receiving immunosuppressive treatment for autoimmune disease.

Visceral leishmaniasis (VL) in patients receiving immunosuppressant drugs for autoimmune disease has been on the rise. It is important—but difficult—to know when cure has been achieved in these patients since the withdrawal of immunosuppressants during antileishmania treatment is commonly required, and there is a risk of relapse when immunosuppression is restored. The prevalence of asymptomatic infection among those immunosuppressed for autoimmune disease is also uncertain. The present work describes how cytokine release assays can be used to confirm the cure of VL, and to determine the prevalence of asymptomatic infection, in such patients. After collection of blood from volunteers (n = 108), SLA-stimulation of peripheral blood mononuclear cell cultures and of whole blood was found to induce the production of different combinations of cytokines that served to confirm recovery from VL, and asymptomatic Leishmania infection. Indeed, cure was confirmed in 14 patients, all of whom showed a specific Th1 immune response against Leishmania, and the prevalence of asymptomatic infection was determined as 21.27%. Cytokine profiles could be used to manage VL in patients with autoimmune disease, and to identify and better protect those with asymptomatic infection who are at risk of developing this disease.

Comparison of the characteristics of adult liver transplant recipients with prope (almost) tolerance and full immunosuppression regimen

The liver transplant recipients are often subjected to excessive therapy by immunosuppressive drugs which produce several complications. Consequently, the minimization or even withdrawal of immunosuppression in selected patients is an attractive alternative. We investigated the frequency and characteristics of these near (or prope from Latin) tolerance in liver transplant recipients in Shiraz Organ Transplant Center. We reviewed the medical records of over 3800 adult liver transplant recipients to select a group treated with a low-dose tacrolimus monotherapy (n=90) between 1994 and 2017 in our transplant center. The patients with the best liver function parameters were selected; then, the clinician arbitrarily decided to withdraw steroids first and then mycophenolate mofetil and maintain each patient on a low dose tacrolimus. We compared the characteristics of prope tolerant recipients on a low-dose tacrolimus with those on standard immunosuppression, namely full-dose tacrolimus plus steroids and mycophenolate mofetil (n=233). Data were analyzed by t-test, chi-square test using SPSS software version 16. Out of over 3800 liver transplant patients, 90 (2.34%) recipients were treated with a minimum dose of tacrolimus monotherapy. These recipients were compared to a selected group of 233 (6.1%) recipients treated with full-dose tacrolimus plus steroids and mycophenolate mofetil. In a prope tolerant group, there were 55 males (61.1%) and 35 females (38.9%) recipients. Mean age at the time of transplant was 39.92±(SD=13.40) years with an average time from the transplantation time to completed weaning from triple immunosuppression to low-dose monotherapy of 41.35months (SD=17.27). The most common etiology of liver disease among both groups was viral hepatitis. The achievement of prope (almost) immune tolerance was possible only in some liver transplant recipients with a relatively low risk of rejection. Our analysis suggests that there is a difference in the underlying diseases and recipients' age and the number of rejections between the two groups.

Auxiliary liver transplantation for acute liver failure

Contents 1. What is auxiliary LT (ALT)? 2. When does ALT need? 3. What are issues of ALT for acute liver failure (ALF)? 4. Who can be a good candidate for ALT? 5. How to carve out a niche of technical challenges 6. How to manage Post-ALT patients 7. A SNUH case: A video clip 8. Reappraisal of ALT for ALF for Expanding Organ Utility. An APOLT (auxiliary partial orthtopic liver transplantation) for ALF has a benefit of immunosuppressant discontinuation in 60%-100% without compromising patients' survival outcome. This can also provide to expand the donor pool in some aspect. However, it's technically challenging as well as graft function and native liver regeneration is usually unpredictable. Thus, selection of good candidates (young, biopsy guided, hemodyenamically stable) and delicate surgical modification are important to lead a successful APOLT for ALF. In addition, this should be supported by careful postoperative monitoring and slow/steady immunosuppressant withdrawal after confirmation of native liver function restoration.

Selection of immunosuppressive drugs after liver transplantation

Corticosteroids and antimetabolites, with the addition of calcineurin inhibitors (CNIs) a decade later, were the first immunosuppressive agents used among liver transplantation (LT) recipients. They are currently among the most common choices for immunosuppression (IS). Development of the IS after LT allow nowadays to obtain remarkable results. However, lifelong IS is associated with severe adverse events like infectious, cardiovascular, renal, metabolic, and oncologic complications that leads to major morbidity and mortality. Consequently, there is ongoing studies for effective immunosuppressive regimens with acceptable side effects. Newer protocols include combinations of drugs with different modes of action and toxicity profiles. The two prominent approaches are as follows: the upfront strategy in which the immunosuppressive drugs were selected with respect to patient's pretransplant and/or intraoperative risk factors, and the downstream strategy in which a standard therapy is given and changed according to its toxicity and efficacy during the course of therapy. Corticosteroids are employed in immediate and early postoperative period. Although they have a pronounced side effect profile, CNIs are still the backbone of early and late phase immunosuppressive regimens because of their proved efficacy. Antimetabolites are frequent choices for steroid and/or CNI-sparing strategies. Studies also have established a role for mammalian target of rapamycin (mTOR) inhibitors in specific groups of recipients. Biologic agents are a hot topic of interest and made their way into current strategies for induction. IS withdrawal seems feasible in very long-term survivors (> 10 years), but is not associated with reversal of IS-related complications. Awaiting novel immunosuppressive drug categories, integration of upfront strategies with the aim to reduce CNI-exposure and a low threshold for adjustment in the posttransplant course are advisable to improve long-term outcomes of LT.

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

Abstract 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. Disclosures Park: 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.

Post-Allogeneic Stem Cell Transplant Surveillance of CD34+ Sorted Peripheral Blood to Quantify Emergent DNMT3A, IDH and NPM1 clones and Correlation with Clinical Outcome

Abstract Introduction - Rising NPM1 mutant minimal residual disease (MRD) is strongly associated with relapse post-chemotherapy for Acute Myeloid Leukaemia (AML). Utility of other mutations affecting DNMT3A, IDH1 and IDH2 for MRD tracking has been hampered by persistence of clonal hematopoiesis after chemotherapy. In the post-allogeneic stem cell transplant (alloHSCT) context however, we show that host-derived clonal hematopoiesis is erased by donor hematopoiesis. We therefore sought to examine kinetics of re-emergence of host-derived mutations in CD34+, CD33+ CD3+ fractionated peripheral blood (PB) and correlation with loss of donor chimerism (DC) and clinical outcome. Aim - To utilize ddPCR monitoring to track mutant DNMT3A, IDH1, IDH2 and NPM1 clones in CD34+/CD33+ and CD3+ sorted peripheral blood fractions following alloHSCT for AML. Methods - Patients undergoing alloHSCT between January 2014 and December 2016 with known mutations in the hotspot regions of DNMT3A, IDH1, IDH2 and NPM1 as detected by Sequenom Mass Array were included in the analysis cohort. An unfractionated pre-transplant peripheral blood sample was utilized for mutation determination, with serial fractionated PB samples analyzed and stored as part of routine DC assessment. DC was assessed by selection of disparate donor-recipient short tandem repeats (STR) sequences. CD3+, CD33+ CD34+ cell fractions sorted using MAC beads. Cell fractions with sufficient input DNA were analyzed by ddPCR utilizing FAM and HEX probes to quantify mutant and wildtype DNMT3A R882H and R882C, IDH1 R132C and R132H, IDH2 R140Q and NPM1 insA. Mutant and wild-type copy number was determined utilizing Poisson statistics and fractional abundance (FA) determined. Statistical analysis was performed in R version 3.3.2 and GraphPad Prism version 7.0b. Results - 23 patients were analyzed with 9 with DNMT3A (8 R882H, 1 R882C), 2 IDH1 (1 R132C, 1 R132H), 6 IDH2 (all R140Q) and 14 NPM1 insA mutations. Demographic information is summarized in table 1. Based on known mutational profile of the cohort, FA of pre-transplant DNMT3A and IDH mutations ranged between 0.06% - 45.8%, while only 1 of 7 pre-transplant NPM1 samples was positive (0.0512%). FA rose earlier in CD34 fraction, then in CD33 or CD3 fractions. In 9 out of 10 paired pre-transplant and post-transplant samples, there was a significant reduction in FA (median 97% reduction), despite a variety of conditioning intensities. Many positive post-transplant blood specimens represented pre-leukemic mutations, with mutant positivity in both CD34+ and CD3+ fractions. In 6/6 cases with either a persistently high or rising peripheral blood mutant FA, clinical relapse occurred (Figure 1A). All 5 subjects with a progressive rise in mutant burden had detectable disease prior to clinical disease relapse by a median of 30 days (range 25 - 51 days). Low-level ( Conclusion - Monitoring of DNMT3A, IDH1, IDH2 and NPM1 mutations in peripheral blood sorted fractions post alloHSCT was feasible and a valuable adjunct to chimerism monitoring. CD34+ sorted peripheral blood samples were most sensitive for early detection of molecular relapse. Serial PB monitoring of recurrent AML mutations, including pre-leukemic clones, may have utility after SCT for AML. Prospective studies of mutational tracking and therapeutic intervention are suggested. Download : Download high-res image (186KB) Download : Download full-size image Disclosures Fleming: Abbvie: Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astellas: Membership on an entity's Board of Directors or advisory committees; BMS: Speakers Bureau; MSD: Speakers Bureau. Spencer: Amgen: Consultancy, Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Wei: AbbVie, Celgene, Servier: Research Funding; AbbVie, Celgene, Novartis, Amgen, Servier: Membership on an entity's Board of Directors or advisory committees; AbbVie, Celgene, Novartis, Amgen, Servier: Honoraria.

Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia with Monosomy 7 or Deletion 7q: A Study from the Acute Leukemia Working Party (ALWP) of the European Society of Blood and Marrow Transplantation (EBMT)

Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia with Monosomy 7 or Deletion 7q: A Study from the Acute Leukemia Working Party (ALWP) of the European Society of Blood and Marrow Transplantation (EBMT)

Reduction of Immunosuppression after Disease-Specific Donor Cell Chimerism Decrease Can Prevent Hematological Relapse Following Allogeneic Stem Cell Transplantation after Non-Myeloablative (NMA) Conditioning — Results of a Prospective Phase II Study. Eudract #: 2007-002420-15

Introduction: Relapse of the disease remains a major burden after stem cell transplantation (HCT) following myeloablative conditioning and even more after reduced intensity and non-myeloablative conditioning. Efforts to reduce relapse incidence involve early immunosuppression withdrawal and prophylactic buffy coat infusion in high risk patients. In this phase II study we analyzed the role of disease-specific chimerism driven immunosuppression. Methods: Between May 2008 and July 2012, 200 consecutive patients (pts) (130 male and 70 female) with a median age of 62.0 (range 26.2-74.8) years (y) with hematological malignancies were transplanted after NMA conditioning. The conditioning regimen consisted of fludarabine 30mg/m2 and total body irradiation (200 cGy) followed by immunosuppression with cyclosporine A (CSA) and mycophenolate mofetil (MMF). The primary objective of the study was to determine the incidence of relapse after a decrease of >10% disease-specific donor cell chimerism (DCC). Furthermore, the incidence of graft vs. host disease (GvHD) and the reconversion of DCC were investigated. Pts were transplanted for acute myeloid leukemia (AML; n=85; 42.5%), multiple myeloma (MM; n=31; 15.5%), myelodysplastic syndrome (MDS; n=26; 13%), chronic lymphocytic leukemia (CLL; n=22; 11%), B-Non-Hodgkin Lymphoma (B-NHL; n=11; 5.5%), T-NHL (n=6; 3.0%), acute lymphoblastic leukemia (ALL; n=7; 3.5%), myeloproliferative neoplasia (MPN; n=6; 3%), MDS/MPN (n=3; 1.5%) and chronic myeloid leukemia (CML; n=4; 2%). Donors were matched-related (MRD)(n=26;13%), matched unrelated (MUD) (n=129; 64.5%) and mismatched unrelated on allele or antigen level (n=45;22.5%). DCC analyses were performed on flow sorted cells on day (d)+ 28, d +56, d+ 84, d + 180 and every 6 months following. As a disease specific DCC line we used CD34 for AML, MDS and MPN pts, CD19 for CLL and B-NHL, CD138 for myeloma pts. The pts with T-NHL were monitored by CD3 chimerism. In addition, engraftment was monitored by CD3 chimerism. Results: Overall survival was 52.9 (95% Confidence Interval (CI) 46.4 - 60.3)% at 2y, and 43.9 (CI 37.3 - 51.6)% at 5y. Relapse incidence was median 28.2 (CI 22.1 - 34.6)% at 2 y and 30.3 (CI 23.9 - 36.9)% at 5 y. Non-relapse mortality (NRM) was 24.3 (CI 18.5-30.5)% at 2y and 30.4 (CI 23.9-37.1)% at 5y. DCC (≥90%) was observed in 116 of the 200 (58.0%) pts, 43 patients (21.5%) showed incomplete disease-specific DCC or reduction of DCC in association with hematological relapse: AML (n=17), MDS (n=4), MM (n=7), CLL (n=7), B-NHL (n=1), T-NHL (n=1), MPN (n=2), ALL (n=2), CML (n=1), MDS/MPN (n=1) and 41 patients (20%) had an isolated line specific DCC decrease after a median of 106 (28-2975) days following HCT. In the 41 pts with decrease in disease-specific DCC without hematological relapse, 1 was off immunosuppression and 3 pts had an active acute or chronic GvHD. In 37 pts CSA and MMF was reduced prematurely. 5 pts showed acute GvHD grade ≥III after reduction and 32 pts GvHD grade 0-II. Of the 37 pts, 27 (73.0%) showed no increase of DCC. 24 (88.9%) pts died, 18 due to relapse, 6 due to non-relapse causes. 3 pts are alive after salvage chemotherapy. 10 of the 37 patients (26.5%) reached full DCC after a median of 29 (21 - 267) days following immunosuppression taper and one recovered from the decrease of DCC and hematological relapse after discontinuing the immunosuppression. 43 pts (15.5%) showed no full DCC with (n=12) or without hematological relapse (n=31). Following reduction of immunosuppression 32 pts relapsed, of which 4 are alive after salvage therapy. 2 pts rejected the HCT and are alive after 2nd HCT. 85 AML pts were separately analysed, of which 43 experienced a complete DCC at any time point (27 are alive without relapse, 16 died due to non-relapse causes). 25 (29.4%) of which 24 pts were without active GvHD had isolated DCC decreased and were tapered. 7 converted to full DCC. All 17 pts showing no full disease specific DCC with or without simultaneous relapse relapsed. 15 pts died of relapse, 2 are alive after salvage therapy. Conclusion: Decrease of disease-specific DCC was observed in 20% of pts and in 29.4% of the AML pts. Of those 27.7 % in the total population and 29.2 % in the AML group showed recovery of DCC without hematological relapse after tapering of immunosuppression. We conclude that DCC is a useful tool to avoid relapse in the early phase of HCT while the patient is on immunosuppression. Disclosures Franke: Novartis: Honoraria, Research Funding; Pfizer: Honoraria; Takeda: Consultancy. Lange: Novartis: Honoraria, Research Funding. Schwind: Novartis: Consultancy.