Achievement Of Complete Donor Chimerism Research Articles

Outcome of donor lymphocyte infusion for fall in chimerism after hematopoietic stem cell transplant

Achievement of complete donor chimerism after an allogeneic hematopoietic stem cell transplant is necessary for elimination of underlying malignant disease. A decline in donor chimerism may herald an impending relapse and therefore, early recognition and intervention plays an important role in such cases. A 32 year old male patient diagnosed as a case of Philadelphia positive mixed phenotypic acute leukaemia underwent peripheral blood hematopoietic stem cell transplant (HSCT) with his sibling as donor. During follow-up, a fall in donor chimerism was observed from 91.86% on day +37 to 88.83% on day +57 and 85.34% on day +77. Donor Lymphocyte Infusion (DLI) was harvested via apheresis. A dose of 1 × 106 per kg was infused and the rest was cryopreserved in aliquots of escalating doses. On day +102, he presented with biopsy proven acute mucocutaneous GVHD grade 2 which was managed conservatively and donor chimerism of 57.99%. On day +126, a repeat donor chimerism was performed which showed 100% chimerism. He continues to do well at day +161. Timely use of DLI can improve donor chimerism in patients with Philadelphia positive acute leukaemia who tend to relapse after HSCT.

Reduced Intensity Continuous Infusion Busulfan for Allogeneic Hematopoietic Cell Transplant Patients with Hematologic Disorders Who Are Ineligible or Inappropriate for Treatment with a More Intensive Therapeutic Regimen: LCCC 0306

Background: A major advance in allogeneic stem cell transplant (SCT) has been the establishment of effective and less toxic reduced intensity regimens as alternative therapeutic approaches for patients with certain hematologic malignancies. The focus of these approaches has been to reduce treatment related mortality (TRM) while providing sufficient host immunosuppression to permit the achievement of complete donor chimerism that leads to a graft versus tumor effect, resulting in long-term disease control and cure. In this study we report overall survival (OS), relapse rate (RR), and non-relapse mortality (NRM) in patients receiving reduced intensity conditioning (RIC) with a 48 hour continuous infusion of busulfan with fludarabine followed by methotrexate (MTX) alone or with lympho-depleting anti-CD52 monoclonal antibody (mAb), alemtuzumab, or T cell depleting immunoglobulins, anti-thymocyte globulin (ATG) given as graft versus host disease (GVHD) prophylaxis.Methods: Patients with histologically confirmed hematologic malignancies, who were over the age of 55, or otherwise ineligible for more intensive busulfan-based therapy were enrolled on a Phase II protocol, LCCC 0306, at the University of North Carolina. All patients received IV fludarabine 30 mg/m2/day on days-7 through-3; busulfan 6.4 mg/kg by continuous infusion over 48 hours on days-6 through-5 and tacrolimus from day-1 plus either MTX alone, ATG or alemtuzumab alone, or a combination of these agents depending on disease risk and donor status.Results: 71 patients were enrolled. The median age was 58 (range 28 - 69). 58% were men and 42% women. 37 patients received HLA-matched related donor (MRD) stem cell grafts, and 34 patients received either matched unrelated donor (MUD) or HLA-mismatched grafts. The median HCT-Comorbidity Index (CI) score was 3 (range 0 - 8, HCT-CI score: 0 = 12 pts, 1 - 2 = 22 pts, ⪴ 3 = 36 pts). The majority of pts were intermediate risk by Disease Risk Index (DRI) score (9 low, 40 int, 19 high, 1 very high, 2 undetermined). The DRI low/int group had an estimated 18 month OS of 65% (CI 0.50 - 0.77), and DRI high/very high OS was 35% (CI 0.16 - 0.55). Estimated median survival time based on DRI for low/int was 1674 days (CI 646 - 2920) versus 375.5 days (CI 136 - 1018) (p = 0.003) for DRI high/very high pts. OS at 18 months in the MTX alone arm (n = 20) was 70% (CI 0.45 - 0.83), ATG (+/- MTX, n = 27) was 52% (CI 0.32 - 0.69), and alemtuzumab (+/- MTX, n = 24) was 46% (CI 0.26 - 0.64); (p = 0.17). The 18 month relapse rate for the MTX alone arm was 50% (CI 0.27 - 0.69), 41% in ATG (CI 0.37 - 0.76), and 41% in alemtuzumab (CI 0.36 - 0.77); (p = 0.85). The 18 month NRM in the MTX alone arm was 7% (CI 0.61 - 0.99), alemtuzumab (+/- MTX) was 32% (CI 0.42 - 0.85), and ATG (+/- MTX) was 27% (CI 0.52 - 0.86); (p = 0.05). Much of the increased NRM in the alemtuzumab and ATG arms was attributable to increased rates of fatal infectious complications: 1 in the MTX arm, 3 in the ATG arm and 8 in the alemtuzumab arm. No patients receiving MTX alone, 3 receiving alemtuzumab and 6 receiving ATG developed grade 3-4 acute GVHD. 5 of the 20 surviving patients have extensive chronic GVHD.Conclusion: Continuous infusion, reduced dose, busulfan and fludarabine can be safely administered to patients who are ineligible for myeloablative conditioning either because of age or comorbidities. The use of MTX alone with this regimen results in a median survival of over 4 years. Patients with high DRI or who received treatment with alemtuzumab or ATG had higher NRM and poorer OS irrespective of donor status. DisclosuresWood:Best Doctors: Consultancy; Inform Genomics: Consultancy.

A Prospective Feasibility Trial of Unrelated Bone Marrow Transplantation with Reduced Intensity Conditioning Regimen for Elderly Patients with Adult T-Cell Leukemia/Lymphoma (ATL),

Abstract 4163 Introduction:ATL is a peripheral T-cell malignancy that is caused by human T-lymphotropic virus type 1 (HTLV-1) infection and commonly affects individuals at an average age of 60 years. Since the prognosis of elderly patients with the disease has been unsatisfactory by conventional chemotherapy, we had so far conducted two clinical trials to evaluate the feasibility of allogeneic hematopoietic stem cell transplantation (allo-SCT) using G-CSF-mobilized peripheral blood stem cells from HLA-identical sibling donors combined with reduced-intensity conditioning regimen (RIC) and reported promising results (Okamura et al, Blood, 2005; Tanosaki et al, Biol Blood Marrow Transplant, 2008; Choi et al, Bone Marrow Transplant, 2011). The availability of suitable sibling donors, however, will become more and more difficult due to the aging as well as complications of donors. In this study, we conducted a clinical trial of an alternative strategy of allo-SCT using bone marrow cells from unrelated donors with RIC for elderly patients with ATL. Study design:Patients between 50 and 65 years of age who satisfied the diagnostic criteria for acute or lymphoma type ATL and had no available HLA matched family donors were eligible. It was required at the time of registration that they were in either complete remission (CR) or partial remission after chemotherapy and had an unrelated donor whose HLA-A, B and DR loci were genotypically matched. DR one locus-mismatched donors were acceptable. All patients were needed their written informed consent to participate in this study which was approved by the institutional review board of each participating institution. The conditioning regimen consisted of fludarabine (180 mg/m2), intravenous busulfan (6.4 mg/kg) and low dose total body irradiation (2Gy). Bone marrow grafts from the Japan Marrow Donor Program were transplanted on day 0. To prevent graft versus host disease (GVHD), tacrolimus (0.03 mg/kg/day) and short-term methotrexate were administered. The primary endpoints of the study were both engraftment, as judged by the achievement of complete donor chimerism before day 100, and survival at day 100 after SCT. The severity of GVHD was graded according to the consensus criteria. The degrees of donor-recipient chimerism and HTLV-1 proviral DNA in peripheral blood mononuclear cells were quantified by published methods. Results and discussion:Fifteen patients were registered between February 2009 and April 2011 at 8 institutions in Japan. The median age of the patients was 58 (range, 51–62). Seven were male, 12 had acute type, and 7 were in CR. Median period from diagnosis to SCT was 7 months (range, 4–12). There were 9 pairs of patient and donor with HLA fully matched, and HLA-DR one locus-mismatched pairs were six. All donors were negative for anti-HTLV-1 antibody. One patient who developed an early relapse failed to achieve complete donor chimerism before day 100, resulting in 14 out of 15 patients with complete donor chimerism. One other patient developed an early treatment-related death on day 34 due to sever thrombotic microangiopathy-related toxicities. Thus, 13 of 15 patients achieved the primary objective. Disease progression was observed in 3 patients at a median follow-up period of 530 (range, 108–864) days. Acute GVHD was observed in 10 of 15 patients, where 2/6/2 patients experienced grade 3/2/1. Kinetics of the HTLV-1 proviral load after SCT showed that it decreased to an undetectable level (< 0.5 copies) in 10 of 14 patients who survived beyond 100 days. In conclusion, this study firstly indicated that SCT using bone marrow cells with RIC from unrelated donors is a feasible therapeutic procedure for elderly patients with ATL. Disclosures:No relevant conflicts of interest to declare.

Influence of killer immunoglobulin-like receptor/HLA ligand matching on achievement of T-cell complete donor chimerism in related donor nonmyeloablative allogeneic hematopoietic stem cell transplantation

Achievement of complete donor chimerism (CDC) after allogeneic nonmyeloablative hematopoietic stem cell transplantation (NMHSCT) is important for preventing graft rejection and for generating a graft-vs-malignancy effect. The alloreactivity of NK cells and some T-cell subsets is mediated through the interaction of their killer immunoglobulin-like receptors (KIRs) with target cell HLA/KIR ligands. The influence of KIR matching on the achievement of T-cell CDC after NMHSCT has not been previously described. We analyzed 31 patients undergoing T-cell replete related donor NMHSCT following fludarabine and 200 cGy TBI. Recipient inhibitory KIR genotype and donor HLA/KIR ligand matches were used to generate an inhibitory KIR score from 1 to 4 based upon the potential number of recipient inhibitory KIRs that could be engaged with donor HLA/KIR ligands. Patients with a score of 1 were less likely to achieve T-cell CDC (P=0.016) and more likely to develop graft rejection (P=0.011) than those with scores greater than 1. Thus, patients with lower inhibitory KIR scores may have more active anti-donor immune effector cells that may reduce donor chimerism. Conversely, patients with greater inhibitory KIR scores may have less active NK cell and T-cell populations, which may make them more likely to achieve CDC.

Chimerism Status as a Possible Marker of Incipient Disease Relapse in Patients with AML.

The connection between chimerism status and occurence of relapse in patients undergoing hematopoietic stem cell transplantation remains controversial. One reason for this seems to be employment of different methods with inherrited different sensitivity and related definition of complete donor chimerism (CDC). We compared an application of fragment analysis (FA) of minisatellite, microsatellite or sex specific regions (limit of quantification ∼1%) with real-time quantitative PCR (RQ-PCR) of insertion/deletion and sex polymorphism (limit of quantification ∼0.1%). Long-term data (follow-up 1.8–7.4 years, median 3.3 years) obtained from two groups of AML patients transplanted in our centre are presented. The first group involves 9 patients that experienced relapse (one of them three times) whereas the second one contains 11 individuals in complete remission. Retrospective chimerism analysis of patients in the first group by RQ-PCR allowed prediction of hematological relapse significantly earlier (p=0.016) than quantification by FA, (35–448 days, median 77 days by RQ-PCR vs. 0–154 days, median 35 days by FA). Beside this, in two cases the incipient relapse was detected only by RQ-PCR and not by FA, 118 and 70 days in advance. Moreover, in two patients with fusion gene, there was detection of molecular relapse recorded simultaneously by either increase of autologous hematopoiesis or conversion of CDC to MC in granulocytes, as revealed by analysis of sorted leukocyte subsets. On the other hand, after achievement of CDC within the group of patients in complete remission, the amount of detectable autologous DNA did not repeatedly exceeded the limit of quantification of RQ-PCR. The CDC was not achieved in one case only, whereas lineage-restricted analysis persistently shows MC in T-lymphocytes (1–3% of autologous origin). Our data demonstrate, that assessment of chimerism by RQ-PCR along with analyses within specific leukocyte subsets can provide an early indication of incipient disease relapse of AML and could be used for residual disease monitoring in cases, where another specific marker is not available.

Reduced-Intensity Stem Cell Transplantation for Adult T-Cell Leukemia: The Results of a Second Multi-Center Prospective Study and the Impact of Antithymocyte Globulin on Early Relapse.

As we previously reported(Blood, 2005;NST-1), allogeneic stem-cell transplantation from an HLA identical sibling donor with reduced-intensity conditioning(RIST) consisting of fludarabine(FL), busulfan(BU) and antithymocyte globulin(ATG) for adult T-cell leukemia(ATL) patients(pts) appears to be a feasible treatment modality. Disease relapse, however, was the main cause of treatment failure. We conducted a second phase 1 clinical trial of RIST for ATL pts without ATG(NST-2).Objectives: We evaluated the safety and feasibility of RIST for ATL using the same conditioning regimen except that we did not use ATG.Patients and Methods: Between September 2003 and January 2006, 14 pts ranged from 50 and 62 years of age were enrolled. After the conditioning regimen with FL 30 mg/m2/d on days -8 to -3, BU 4 mg/kg/d on days -6 to -5, they received G-CSF-mobilized PB stem cells. The primary end points were either engraftment, as evaluated by the achievement of complete donor chimerism(CC) before d90, or the occurrence of early transplant-related mortality(TRM) before d100.Results: All 14 pts achieved CC before d90, while two pts died of TRM before d100, thus demonstrating the successful results for the primary end points. The incidence of severe acute GVHD(grade III-IV) was 21%. A disease relapse occurred in 6 pts from d30 to d775, 5 of whom eventually died of ATL. As of July 31, 2006, 6 pts are still alive, while 8 died of either ATL(5 pts) or TRM(3 pts). The event free and overall survivals(EFS, OS) at 2 years were 40% and 43%, respectively. Among the 12 evaluable pts, the HTLV-1 proviral load decreased to an undetectable level after RIST in 9 pts. Therefore, the results of CC before d90(14/14versus[vs]14/15*), TRM before d100(2/14vs2/15*), severe acute GVHD(3/14vs5/15*), disease relapse(6/14vs9/15*), 2 year-EFS (40%vs20%*) or -OS(46%vs33%*) and the anti-HTLV-1 effects(9/12vs8/15*) were closely comparable with those of NST-1*. The incidence of early disease recurrence before d100 tended to be low(21%[3/14]vs44%*[7/16]*), thus resulting in a longer mean survival time(804 days vs 262 days*) after RIST.Conclusion: Our two studies(NST-1, NST-2) confirmed that, whether ATG was administered or not, RIST is considered to be a feasible treatment modality. Moreover, conditioning without ATG may improve the survival by delaying a disease relapse without increasing the severity of acute GVHD. A third study (phase 2 trial of RIST without ATG) is currently underway.

Successful engraftment and achievement of complete donor chimerism in adult patients with advanced hematological malignancies following reduced-intensity conditioning regimen without total body irradiation undergoing umbilical cord blood transplantation (non-TBI-RICBT)

Successful engraftment and achievement of complete donor chimerism in adult patients with advanced hematological malignancies following reduced-intensity conditioning regimen without total body irradiation undergoing umbilical cord blood transplantation (non-TBI-RICBT)

Efficacy of Donor Lymphocyte Infusions in Myelodysplastic Syndromes Relapsing after Allogeneic Stem Cell Transplantation: Importance of Karyotype.

Few studies have reported on the efficacy of donor lymphocyte infusions (DLI) for myelodysplastic syndromes (MDS) relapsing after T-cell depleted allogeneic stem cell transplantation. Since 1996 we have treated 11 patients with DLI as a single therapeutic modality (without chemotherapy) for a relapse of MDS after allogeneic stem cell transplantation. Median age of the patients was 56 years (range 23 to 73 years). Initial diagnosis was RAEB (4 patients), RAEBt (3 patients), secondary AML(3 patients) and MDS with fibrosis (1 patient). Conditioning was myeloablative in 10 patients ( TBI -Cyclophosphamide, Busulfan-Cyclophosphamide or Busulfan-Melphalan) and non-myeloablative in 1 patient (Busulfan-Fludarabine-ATG). Source of stem cells was peripheral blood in all patients. Donors were HLA-identical siblings in 10 patients and HLA-matched unrelated in 1 patient. Allografts were T-cell depleted with Campath 1H in the bag in 8 of 11 patients. GVHD prophylaxis was cyclosporin in all patients combined with methotrexate in the 3 patients receiving unmodified stem cells. Relapse of MDS occurred at a median of 123 days (54 to 373 days) after allograft. At the time of DLI the percentage of blast cells in the bone marrow ranged from 3 % to 50 % (median 6 %); donor chimerism ranged from 14 % to 91 % (median 72%). The total dose of CD3 lymphocytes ranged from 0.1 to 30 x 10 7 /kg (median 0.6 x 10 7/kg) and was administered in 1 to 4 infusions (median 1). Time interval between first and second DLI varied between 7 and 180 days.Three of the 11 patients achieved a durable complete remission with 100 % donor chimerism after DLI. These 3 patients are currently disease free at 20, 30 and 40 months from the first DLI. All durable responses were associated with limited chronic GVHD requiring temporary immunosuppressive therapy. Time interval between the first DLI and the achievement of complete donor chimerism varied between 6 weeks and 9 months. One of the 11 patients achieved a short state of complete chimerism for 4 weeks and died from relapse 146 days after DLI. Five of the 11 patients progressed after DLI and 4 of them died from disease progression at 29 to 112 days after first DLI. Two patients died at 26 and 97 days after the first DLI from acute GVHD grade IV after having received only 1 x 10 6 CD3 lymphocytes /kg from HLA-identical sibling donors. None of the 6 patients with a complex karyotype responded to DLI while 3 of 3 patients with a single chromosomal abnormality ( t(1,14), t(1,17), t(1,3)) had a durable response (p-value = 0.01). We conclude that DLI is a powerful therapy for about 30 % of MDS patients relapsing after T-cell depleted allogeneic stem cell transplantation. DLI may result in durable remissions particularly in patients with non-complex cytogenetic abnormalities. However, even low doses of donor T lymphocytes may cause mortality from severe GVHD.