Human Leukocyte Antigen-matched Donor Research Articles

Fludarabine and busulfan as a reduced-toxicity myeloablative conditioning regimen in allogeneic hematopoietic stem cell transplantation for acute leukemia patients.

The optimal conditioning regimen for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in acute leukemia remains undefined. We evaluated the outcomes in 30 patients with acute leukemia who underwent allo-HSCT from human leukocyte antigen-matched donors after conditioning with busulfan and fludarabine (BuFlu). The regimen comprised injection of busulfan 3.2 mg/kg daily on 4 consecutive days and fludarabine 30 mg/m2 daily for 4 doses. All 30 patients achieved hematopoiesis reconstitution with full donor chimerism confirmed by short tandem repeat DNA analysis. The most common regimen-related toxicity was mucositis (86.7%), followed by cytomegalovirus infection (80%). Serious regimen-related toxicities were rare. Acute graft vs. host disease (aGVHD) was detected in 46.7% of the patients; 33.4% had grade I-II aGVHD and 13.3% had grade III-IV aGVHD. Chronic GVHD (cGVHD) was noted in 20% of the patients. The overall survival and disease-free survival rates were 66.7 and 53%, respectively, with a median follow-up of 25 months for surviving patients. Therefore, BuFlu was an effective conditioning regimen with a low rate of transplant-related adverse effects and increased antileukemic effects in patients with acute leukemia undergoing allo-HSCT.

Case Reports of Severe Congenital Neutropenia Treated With Unrelated Cord Blood Transplantation With Reduced-intensity Conditioning

Allogeneic stem cell transplantation is a curative treatment for severe congenital neutropenia (SCN). However, a standard conditioning regimen and donor source have not been established. We report 3 consecutive cases of SCN who were successfully treated by cord blood transplantation (CBT) with reduced-intensity conditioning consisting of fludarabine, melphalan, and low-dose total body irradiation. All cases achieved complete donor chimerism without severe infectious complications and have maintained normal neutrophil counts for between 3 and 9 years after CBT. These results suggest that CBT with reduced-intensity conditioning can be an alternative therapy for SCN when human leukocyte antigen-matched bone marrow donor is unavailable.

Prophylaxis of acute graft-versus-host disease

Graft-versus-host disease (GVHD) is an important complication in allogeneic hematopoietic stem cell transplantation. The standard regimen for GVHD prophylaxis in bone marrow transplantation and peripheral blood stem cell transplantation from human leukocyte antigen-matched donors is a combination of a calcineurin inhibitor, such as cyclosporin or tacrolimus, and short-term methotrexate. This regimen is well researched and has been nearly optimized in terms of infusion methods and the target blood concentration. The use of mycophenolate mofetil instead of methotrexate has the advantage of a lower incidence and severity of oropharyngeal mucositis. The addition of anti-thymocyte globulin significantly decreases the incidences of severe acute GVHD and extensive chronic GVHD, but does not lead to a significant improvement in overall survival. The GVHD prophylaxis regimens in cord blood transplantation and HLA-haploidentical donor transplantation have not been standardized. The efficacy of other immunosuppressive drugs, regulatory T lymphocytes, and mesenchymal stem cells are currently under investigation. Establishment of new evidence for GVHD prophylaxis from Japan is expected.

Upfront allogeneic stem-cell transplantation for patients with nonlocalized untreated peripheral T-cell lymphoma: an intention-to-treat analysis from a single center

Peripheral T-cell lymphomas (PTCLs) are rare and heterogeneous diseases with dismal outcome when treated with chemotherapy alone. Because allogeneic stem-cell transplantation (allo-SCT) can cure relapse/refractory patients, we hypothesized that upfront allo-SCT may provide a better outcome. Therefore, all patients that presented with advanced PTCL in our institution at diagnosis were scheduled to undergo upfront allo-SCT after induction chemotherapy. The aim of the present work was to assess the feasibility and toxicity of upfront allo-SCT. From 2004 to 2012, 49 newly diagnosed PTCL patients were scheduled to receive upfront allo-SCT. A human leukocyte antigen-matched donor was found for 42 patients: related to the patient in 15 cases, unrelated in 20 cases, and suitable cord blood units were used in 7 cases. After induction chemotherapy, 17 patients reached complete remission and 29 (60%) proceeded to upfront allo-SCT. For all patients, the 1 and 2-year overall survival (OS) rates were 59% [95% confidence interval (CI) 47-75] and 55% (95% CI 43-71), respectively. The most frequent reason we did not proceed to allo-SCT was disease progression or insufficient response after induction. For transplanted patients, the 1- and 2-year OS were 76% (95% CI 62-93) and 72.5% (95% CI 58-91), respectively. Toxicity-related mortality (TRM) 1 year after allo-SCT was only 8.2% (95% CI 0-18.5). The 2-year progression-free survival (PFS) rate of patients who did not proceed to allo-SCT (n = 20) was below 30%. The disease status at the time of transplantation was a strong predictive marker for both PFS and OS in transplant patients. Upfront allo-SCT in PTCLs is feasible with low TRM, and it provides long-term disease control. However, one-third of patients remain chemo-refractory and, thus, new therapeutic approaches are warranted. The role of upfront allo-SCT compared with other therapeutic approaches in PTCLs requires investigation in randomized studies.

Cell replacement therapies: is it time to reprogram?

Hematopoietic stem cell transplantations have become a very successful therapeutic approach to treat otherwise life-threatening blood disorders. It is thought that stem cell transplantation may also become a feasible treatment option for many non-blood-related diseases. So far, however, the limited availability of human leukocyte antigen-matched donors has hindered development of some cell replacement therapies. The Nobel-prize rewarded finding that pluripotency can be induced in somatic cells via expression of a few transcription factors has led to a revolution in stem cell biology. The possibility to change the fate of somatic cells by expressing key transcription factors has been used not only to generate pluripotent stem cells, but also for directly converting somatic cells into fully differentiated cells of another lineage or more committed progenitor cells. These approaches offer the prospect of generating cell types with a specific genotype de novo, which would circumvent the problems associated with allogeneic cell transplantations. This technology has generated a plethora of new disease-specific research efforts, from studying disease pathogenesis to therapeutic interventions. Here we will discuss the opportunities in this booming field of cell biology and summarize how the scientists in the Netherlands have joined efforts in one area to exploit the new technology.

Primary distal femur T-cell lymphoma after allogeneic haematopoietic stem cell transplantation for chronic myeloid leukaemia: A rare case report and literature review

Post-transplant lymphoproliferative disorders originating from T lymphocytes are a rare complication of allogeneic haematopoietic stem cell transplantation (allo-HSCT) that are not usually associated with Epstein-Barr virus infection. A male patient diagnosed at the age of 15 years with chronic myeloid leukaemia (in the chronic phase) was initially treated with oral hydroxyurea. The disease entered an accelerated phase when the patient was 22 years old. Complete remission was achieved after one course of homoharringtonine and cytarabine. The patient then underwent human leucocyte antigen-matched sibling donor allo-HSCT. Just over 6.5 years after the allo-HSCT, a second primary tumour was located in the distal femur and diagnosed as T-cell non-Hodgkin's lymphoma (stage IV, group B). This was treated with various chemotherapy and radiotherapy regimens, but the outcomes were poor and the disease progressed. The T-cell lymphoma invaded many sites, including the skeleton, spleen and skin, and the patient died within 8 months of the diagnosis. This current case report highlights the need for the early detection and prevention of subsequent primary malignancies after allo-HSCT.

Successful Unrelated Cord Blood Stem Cell Transplantation in an X-linked Chronic Granulomatous Disease Patient with Disseminated BCG-induced Infection

A 19-month-old boy with chronic granulomatous disease (CGD) received umbilical cord blood transplantation (UCBT) from an unrelated donor after experiencing a life-threatening disseminated Bacillus Calmette-Guérin infection. After busulfan and cyclophosphamide conditioning, we performed a 5/6-matched UCBT. Engraftment and mixed chimerism was 100% in peripheral blood, and 100% of his neutrophils had normal oxidative burst activity on day 17. The patient is now 3 years old, free from infection, and growing well. To our knowledge, this is the second case of CGD treated with UCBT in Taiwan. His successful outcome illustrates that UCBT in a patient with CGD should be considered early if a human leukocyte antigen-matched donor is not available or the patient has just recovered from a severe infection.

New strategies in cord blood cells transplantation

For patients lacking a human leucocyte antigen-matched donor, umbilical cord blood (UCB) is an ideal, alternative source of haematopoietic stem cells (HSCs) for transplantation purposes. UCB has many advantages over bone marrow or peripheral blood taken from volunteer donors. UCB is also an important source of other stem cells, including endothelial progenitors, mesenchymal stem cells, very small embryonic/epiblast-like (VSEL) stem cells, and unrestricted somatic stem cells, which are potentially suitable for regenerative medicine. However, a significant clinical problem is that the number of HSCs in one cord-blood unit is not enough for an adult transplantation. The development of new approaches including use of multiple donors, ex vivo expansion, increasing efficiency of homing and engraftment, retrieving more cells from the placenta and cord blood is of crucial importance for the delayed engraftment after UCB transplantation. In the future, UCB will emerge as a source of cells for cellular therapies associated with tissue repair and regeneration.

Umbilical Cord Blood: An Evolving Stem Cell Source for Sickle Cell Disease Transplants

Allogeneic hematopoietic stem cell transplantation has proven benefit in controlling sickle cell disease-related vasculopathy and organ damage. Myeloablative matched sibling donor cord transplants have excellent outcomes in sickle cell disease. Unrelated donor transplant options are often deferred because of a lack of suitable human leukocyte antigen-matched donors, a problem especially relevant to minority populations. Umbilical cord blood transplantation allows for more mismatching from the graft-versus-host disease perspective and the donor pool is expandable with effort and education. Drawbacks such as increased rates of graft rejection, a fixed cell dose, delayed immune reconstitution, and transplant-related mortality have deterred unrelated cord transplant efforts. However, the transplant community continues to make enormous strides in this transplant realm in areas of immunogenetics, stem cell expansion, conditioning regimens, and supportive care. This has allowed the development of new studies that are currently ongoing, exploring ways to make cord blood transplantation successful and safer. The goal is to make unrelated donor cord blood transplantation for sickle cell disease merit early consideration in patients who stand to benefit from this approach.

Cord blood transplantation for the treatment of acute leukemia

Objective This review discussed the available data on treatment outcomes of cord blood transplantation (CBT) for acute leukemia. Data sources The data cited in this review were obtained from articles listed in Medline and Pubmed. Study selection We reviewed the articles of clinical results from various registries and institutions, as well as our experiences with CBT in children, adolescents and adults. Results This research has clearly shown that cord blood (CB) has several unique characteristics resulting in distinct advantage and disadvantages when compared to transplantation with unrelated donor bone marrow or peripheral blood stem cells. The field of CBT has advanced from investigating its safety and feasibility to addressing more specific issues such as accelerating engraftment, extending access, and examining outcomes in specific subgroups of patients. Many approaches have been investigated in the attempt to improve engraftment and survival. Variable factors have been identified, such as factors related to donor choice (human leukocyte antigen (HLA) compatibility, cell dose, and others) and transplantation (conditioning and graft-versus-host disease prophylaxis regimen). Data support that CB should be considered a reasonable option in those that do not have HLA matched sibling donor and for those in whom the time to transplant is critical. Conclusions CB is a reasonable alternative to unrelated donor bone marrow or peripheral blood progenitor cells for transplantation. Recently developed strategies aimed at improving hematopoietic recovery and reducing early transplantation-related mortality could further improve treatment outcomes of CBT for patients with acute leukemia.

Haploidentical bone marrow transplants for haematological malignancies using non‐myeloablative conditioning therapy and post‐transplant immunosuppression with cyclophosphamide: results from a single Australian centre

To demonstrate safety and efficacy of haploidentical bone marrow transplantation with non-myeloablative conditioning and high-dose post-transplant cyclophosphamide in adult patients with leukaemia or lymphoma. Human leukocyte antigen haploidentical bone marrow transplantation is a treatment option in patients with haematological malignancies who have no available human leukocyte antigen-matched donor but is limited by conditioning regimen toxicity, graft failure, relapse and graft-versus-host disease (GvHD). Twelve patients, median age of 51 years, underwent transplantation with T cell replete bone marrow from a haplotype-matched relative. The conditioning regimen consisted of cyclophosphamide, fludarabine and low-dose total body irradiation. Post-transplant immunosuppression consisted of a single dose of cyclophosphamide 50 mg/kg on day 3, followed by oral tacrolimus and mycophenolate mofetil. Outcomes reported are overall survival, engraftment and chimerism, toxicity, and clinical outcome. All patients had neutrophil recovery (median 14.5 days), and 11 of 12 had platelet engraftment (median 17 days). Two patients had autologous reconstitution. Seven of nine assessable patients had complete donor chimerism. Four patients had grades II-III GvHD, and none had grade IV GvHD. Four patients developed limited stage chronic GvHD. Five patients with acute myeloid leukaemia relapsed. Two patients died of nonrelapse causes, both from other malignancies, and five patients remain alive and relapse free. Median overall survival was 324 days (range 88-1163). This regimen is feasible and well tolerated in older patients with high-risk leukaemia or lymphoma, with minimal short-term toxicity and low rates of GvHD. The proportion of disease-free survivors indicates a graft-versus-malignancy effect is present in survivors.

HIV infection

At a satellite meeting prior to the International AIDS Meeting in Washington DC in July, a great deal of discussion was focused on finding a “cure” for HIV infection [1]. While this objective has been discussed at various times over the past decade, the real incentive for this goal comes from the encouraging findings with Timothy Brown, also known as the “Berlin patient.” This HIV-infected man received hematopoietic stem cells from an HLA-matched donor whose genome naturally lacked CCR5, the major receptor for HIV. Five years after two transplants, Mr. Brown appears to be cured of HIV as well as leukemia [2]. Although potentially infected with both a virus that requires CCR5 for entry and a small population of viruses that can infect cells by another receptor, no infectious virus can be recovered from his blood and other tissues. This finding includes biopsies from the brain, bowel, and lymph nodes. Certainly his “cure” encourages approaches that could mimic this achievement in all HIV-infected individuals.

Linezolid‐induced pure red cell aplasia in a patient with Staphylococcus epidermidis infection after allogeneic stem cell transplantation

Linezolid (LZD) is the first oxazolidinone antibiotic that is effective against drug-resistant gram-positive organisms. Hematological toxicities such as thrombocytopenia, anemia, and leukocytopenia are common in LZD therapy. However, LZD-induced pure red cell aplasia (PRCA) is very rare. A 56-year-old man with myelodysplastic syndrome underwent allogeneic bone marrow transplantation from a human leukocyte antigen-matched and ABO blood type-matched unrelated male donor. He had bacteremia caused by Staphylococcus epidermidis after engraftment of neutrophils and red blood cells. We first administered vancomycin, but then changed to intravenous LZD because of kidney damage. Two weeks after LZD therapy, the patient's hemoglobin and reticulocyte levels were 6.8 g/dL and 0.3%, respectively. Bone marrow examination revealed red blood cell aplasia (myeloid/erythroid ratio was 402). The patient showed rapid recovery of normal erythropoiesis within 2 weeks of LZD cessation. It is important to be aware of the hematological effects associated with LZD in the setting of stem cell transplantation,particularly for those with pre-existing myelosuppression, renal insufficiency, and those receiving concomitant drugs that produce bone marrow suppression. We advocate that a reticulocyte count be performed periodically for detecting bone marrow suppression, including PRCA, during LZD therapy.

Gene therapy for primary immunodeficiency

Haematopoietic stem cell transplantation (HSCT) is the mainstay of definitive treatment for children with a wide spectrum of primary immunodeficiencies (PIDs), but outcome is heavily dependent on the availability of a human leukocyte antigen-matched donor. Gene therapy using autologous gene-corrected haematopoietic stem cells is an alternative for patients who lack an appropriate donor and has been used to treat children and adults with specific forms of PID, such as severe combined immunodeficiency, for over 10 years. This review summarizes the encouraging long-term outcome data available from these clinical trials and considers the important adverse events that have arisen. Current strategies directed towards improving the efficacy and safety profile of gene therapy will be discussed. Effective clinical trials have been conducted for other forms of PID including chronic granulomatous disease and Wiskott-Aldrich syndrome. Preclinical and clinical studies are now focussed on the development of improved viral vectors giving more regulated or tissue-specific transgene expression with reduced mutagenic potential. Gene therapy offers a valuable alternative management option for selected immunodeficiency patients who lack a suitable donor for HSCT. Clinical trials have confirmed proof-of-principle in terms of stem cell transduction and subsequent immune reconstitution, but have also highlighted the potential for clonal disturbances related to semi-random vector insertion within the genome.

Transplantation of CD6-depleted peripheral blood stem cells after DLA-haploidentical bone marrow transplantation contributes to engraftment and tolerance in a preclinical model of stem cell transplantation

Human leukocyte antigen (HLA)-haploidentical stem cell transplantation is an opportunity for nearly all patients lacking an HLA matched stem cell donor. However, graft rejection and graft-versus-host disease (GvHD) as well as infectious complications still result in high treatment-related mortality. Here, we used the dog as a preclinical model for the study of tolerance induction with the aim to optimize and to improve a clinical protocol of haploidentical stem cell transplantation. For this purpose CD6-depleted peripheral blood stem cells (PBSCs) were transfused 6 d after transplantation of unmodified bone marrow from dog leukocyte antigen (DLA)-haploidentical littermate donors in order to induce immune tolerance. Besides hematopoietic stem cells CD6-depleted PBSC contain, NK cells and a minority of suppressive CD8-positive cells that may suppress activated T lymphocytes. Recipients were conditioned with, cyclophosphamide and antithymocyte globulin (ATG) preceded by a transfusion of donor buffy coat and either 1, 2 or 3 × 3.3 Gy total body irradiation (TBI). Postgrafting immunosuppression was limited to 30 d of cyclosporine and methotrexate. The additional administration of CD6-depleted PBSCs after unmodified marrow could not prevent GvHD, but it may improve engraftment and chimerism after conditioning with 2 × 3.3 Gy TBI. Reasons for incomplete suppression and possible improvements for clinical applications are discussed.

Allogeneic hematopoietic transplantation using haploidentical donor vs. unrelated cord blood donor in pediatric patients: a single-center retrospective study

We retrospectively analyzed outcomes in 67 children with acute leukemia who received hematopoietic stem cell transplantation from alternative allogeneic donors: 29 received a haploidentical family donor and 38, an unrelated cord blood donor. All transplantations were performed from 1996 through 2010 in our center. Neutrophil and platelet engraftment were significantly delayed after cord blood transplantation. The median times to neutrophil and platelet recovery were 13 d (7-34) and 11 d (5-70) after haploidentical transplant and 20 d (9-125) and 56 d (12-200) after cord blood (P < 0.001). All supportive care measures included red blood cell, and platelet transfusions were significantly increased in cord blood transplantation group.Transplant-related mortality rates was lower with haplo donors (25 ± 9%) than with cord blood donors (47 ± 9%) (P < 0.05). Acute graft-versus-host disease (GVHD) more than grade II was also lower in haploidentical transplants (19 ± 7%) than in cord blood transplants (44 ± 10%) (P < 0.03). Relapse and chronic GVHD incidence were not significantly different in the two groups. Leukemia-free survival was higher after haploidentical transplants (44 ± 10%) than after cord blood transplants (33 ± 7%) (P < 0.03). Main differences were observed in patients diagnosed with acute lymphoblastic leukemia: haplo, 41 ± 13%; cord blood, 26 ± 9% (P < 0.03) and in advanced phase of disease: haplo, 37 ± 14%; cord blood, 21 ± 8% (P < 0.05). In conclusion, haploidentical transplants are a good and promising alternative option for patients with childhood leukemia who lack an human leukocyte antigen-matched donor (sibling or unrelated donor).

Successful sustained engraftment after reduced-intensity umbilical cord blood transplantation for adult patients with severe aplastic anemia

AbstractWe retrospectively analyzed 12 consecutive adult severe aplastic anemia patients who received unrelated umbilical cord blood transplantation after a reduced-intensity conditioning regimen (RI-UCBT). The conditioning regimen consisted of 125 mg/m2 fludarabine, 80 mg/m2 melphalan, and 4 Gy of total body irradiation. The median infused total nucleated cell number and CD34+ cell number were 2.50 × 107/kg and 0.76 × 105/kg, respectively. Eleven of the 12 patients achieved primary neutrophil and platelet engraftment. All patients who achieved engraftment had complete hematologic recovery with complete donor chimerism, except for one patient who developed late graft failure 3 years after RI-UCBT. Two of the 12 patients died of idiopathic pneumonia syndrome, and the remaining 10 patients are alive, having survived for a median of 36 months. Our encouraging results indicate that RI-UCBT may become a viable therapeutic option for adult severe aplastic anemia patients who lack suitable human leukocyte antigen-matched donors and fail immunosuppressive therapy.

Danazol as first-line therapy for aplastic anemia

Immunosuppressive therapy (IST) with anti-thymocyte globulin (ATG) plus cyclosporine A (CsA) is the standard treatment for aplastic anemia (AA) patients not eligible for allogeneic hematopoietic stem cell transplantation (HSCT). In the absence of ATG + CsA, androgens continue to be a treatment option. We documented the clinical evolution of AA patients treated with danazol instead of ATG + CsA. AA patients lacking both, human leukocyte antigen-matched donor and access to IST, were treated with danazol and modern support therapy and compared with those receiving a HSCT. Overall survival (OS), response rates, and death risk odds were calculated. Fifty AA patients were studied. Thirteen received a HSCT and 37 danazol and support therapy. Median daily dose of danazol was 400mg (300 to 600mg), administered during a median of 12months. Five-year OS was higher for patients receiving HSCT (92%) compared to the danazol group (41%) (P = 0.001). Overall response rate was 46% (17/37) in the danazol-treated group and the median time to initial response was 3months (1-27). Tendency to achieve remission was similar among severity groups (P = 0.094). The only adverse side effect recorded on the danazol group was an episode of gastrointestinal bleeding. No patient treated with danazol suffered clonal evolution of his/her disease. Although ATG plus CsA is the therapy of choice for AA patients without a donor when neither HSCT nor IST is available, danazol remains an acceptable therapeutic option for AA patients.

Research Highlights

Research Highlights

Clinical Expansion of Cord Blood-derived T Cells for Use as Donor Lymphocyte Infusion After Cord Blood Transplantation

Allogeneic stem cell transplantation (SCT) from cord blood (CB) as a stem cell source is a promising alternative when no human leukocyte antigen-matched donor is found. Donor lymphocyte infusion (DLI) is a possible treatment modality for threatening graft failure or relapse of an underlying malignancy after transplantation. Ethical and logistical reasons limit the possibility of DLI in the setting of CB SCT. To remedy this restriction, we performed expansion of donor T cells in vitro from CB grafts in a clinical setting for use as future DLI and characterized the expanded cells in comparison to T cells from CB acquired ex vivo and adult peripheral blood. T cells were expanded from grafts used for transplantation, upon CD3/CD28 crosslinking and culture in interleukin-2. Phenotype and function of T cells were assessed by flow cytometry and mixed lymphocyte culture assays. T-cell receptor repertoire distribution was evaluated with polymerase chain reaction-based spectratyping. We were able to amplify T cells to sufficient amounts for DLI in 13 out of 13 initiated expansions. Expanded T cells presented with an activated phenotype and could be induced to produce cytokines by a nonspecific stimulus. When exposed to allogeneic targets, expanded CB T cells proliferated at comparable levels to their ex vivo and adult blood counterparts. In summary, clinical expansion of CB T cells for DLI is feasible and may be a future modality for treatment of graft failure or relapse after SCT.