Analysis of 500 bone marrow transplants from unrelated donors (UR-BMT) facilitated by the Japan Marrow Donor Program: confirmation of UR-BMT as a standard therapy for patients with leukemia and aplastic anemia

Effect of HLA mismatching at HLA-A, -B, and -DRB1 for umbilical-cord blood transplantation in Taiwan

Unrelated cord blood transplantation has become a reliable alternative therapy for children and adults owing to that one or two antigen/allele mismatches between a patient and the cord blood donor are acceptable without occurrence of graft-versus-host disease. To investigate the relationship between the number and types of mismatches and relapse, we compared the number of mismatched and non-mismatched donor-recipient pairs, number of mismatched alleles, and number of mismatched antigens at each of the Human Leukocyte Antigen (HLA) -A, -B, and -DR loci, respectively. The result indicates that the number of mismatched antigens at the HLA-A locus was significantly associated with occurrence of relapse (X²P-value=0.0243; RR=1.49, 95% CI: 1.04-2.13). Additionally, the number of mismatched donor-recipient pairs and the number of mismatched alleles at the HLA-DR locus was negatively associated with risks of relapse (X²P-value=0.0028; RR=0.52, 95% CI: 0.31-0.89). In this study, we found that the mismatch at the HLA-A locus is associated with increased risk of relapse; while the mismatch at the HLA-DR locus is innocuous. Hence, we suggest that the well-matched HLA-A alleles were most critical for matching HLA alleles between umbilical-cord blood transplantation donors and recipients. In other words, cord blood transplantation requires less stringent HLA matching, if there are two 5/6 or 4/6 HLA matched donors, it's better to choose HLA-A matched donor at least.

Mycophenolate mofetil use after unrelated hematopoietic stem cell transplantation for prophylaxis and treatment of graft-vs.-host disease in adult patients in Japan

Our previous study of 301 patients who received hematopoietic stem cell transplantation (HSCT) from related donors demonstrated the efficacy of mycophenolate mofetil (MMF) for prophylaxis and treatment of graft-vs.-host disease (GVHD). In this study, we investigated the safety and efficacy of MMF in 716 adult patients who received unrelated HSCT. The incidences of Grade II-IV and III-IV acute GVHD in the prophylactic administration group were 38.3% and 14.3%, respectively. These rates were not statistically significant when evaluating the MMF dosage and graft source. The incidences of limited and extensive chronic GVHD were 16.6% and 11.1%, respectively. In the therapeutic administration group, 69.1% of the subjective symptoms for both acute and chronic GVHD improved. With respect to the adverse events, 75 infections and 50 cases of diarrhea were observed, and the frequency of these events increased with increasing MMF dose. The overall survival rate was 36.4% after a median follow-up period of three yr. This study shows that MMF is safe and effective for the prevention and treatment of GVHD in patients who have received HSCT from unrelated donors.

A novel reduced-intensity umbilical cord blood transplantation using a recombinant G-CSF combined with high-dose Ara-C for active myeloid malignancies

Non-remitting patients with hematologic myeloid malignancies have poor prognosis. To overcome this problem, we investigated the use of reduced-intensity preconditioning umbilical cord blood transplantation (RICBT) combined with recombinant G-CSF (rG-CSF) with high-dose Ara-C, fludarabine, melphalan, and 4 Gy of TBI in a phase I/II study in patients with non-remitting myeloid hematologic malignancies. Thirteen patients were enrolled, including 12 with non-remitting AML and one patient with blastic crisis CML (CML-BC). The patients' median age was 45 years, with a median comorbidity index of 4. All patients received 4/6 serological HLA-antigen matched unrelated umbilical cord blood. All patients were engrafted within 30 days after RICBT (median, 20 days; range, 14-29) and achieved complete remission without prior hematopoiesis. Common grade III non-hematologic toxicities included eight cases of transient mucositis (62%) and six cases of febrile neutropenia (46%). Transplant-related mortality was 7.7%. The 1-year overall survival was 28.6% in cases without post-RICBT treatment and 83.3% in cases with post-RICBT treatment. These data suggest that in active AML and CML-BC, the combination of rG-CSF with high-dose Ara-C and fludarabine/melphalan/4 Gy TBI with a reduced-intensity preconditioning regimen is well tolerated, secures engraftment and has significant anti-leukemia activity. In addition, performing post-RICBT treatment may provide high-quality long-term survival and remission.

First-line allogeneic hematopoietic stem cell transplantation of HLA-matched sibling donors compared with first-line ciclosporin and/or antithymocyte or antilymphocyte globulin for acquired severe aplastic anemia

BACKGROUND

Acquired severe aplastic anemia is a rare and potentially fatal disease, which is characterized by hypocellular bone marrow and pancytopenia. The major signs and symptoms are severe infections, bleeding, and exhaustion. First-line allogeneic hematopoietic stem cell transplantation (HSCT) of a human leukocyte antigen (HLA)-matched sibling donor (MSD) is a treatment for newly diagnosed patients with severe aplastic anemia. First-line treatment with ciclosporin and/or antithymocyte or antilymphocyte globulin (as first-line immunosuppressive therapy) is an alternative to MSD-HSCT and is indicated for patients where no MSD is found.

OBJECTIVES

To evaluate the effectiveness and adverse events of first-line allogeneic hematopoietic stem cell transplantation of HLA-matched sibling donors compared to first-line immunosuppressive therapy including ciclosporin and/or antithymocyte or antilymphocyte globulin in patients with acquired severe aplastic anemia.

SEARCH METHODS

We searched the electronic databases MEDLINE (Ovid), EMBASE (Ovid), and The Cochrane Library CENTRAL (Wiley) for published articles from 1946 to 22 April 2013. Further searches included trial registries, reference lists of recent reviews, and author contacts.

SELECTION CRITERIA

The following prospective study designs were eligible for inclusion: randomized controlled trials (RCTs) and non-randomized controlled trials if the allocation of patients to treatment groups was consistent with 'Mendelian randomization'. We included participants with newly diagnosed severe aplastic anemia who received MSD-HSCT or immunosuppressive therapy without prior HSCT or immunosuppressive therapy, and with a minimum of five participants per treatment group. We did not apply limits on publication year or languages.

DATA COLLECTION AND ANALYSIS

Two review authors abstracted the data on study and patient characteristics and assessed the risk of bias independently. We resolved differences by discussion or by appeal to a third review author. The primary outcome was overall mortality. Secondary outcomes were treatment-related mortality, graft failure, no response to first-line immunosuppressive therapy, graft-versus-host-disease (GVHD), relapse after initial successful treatment, secondary clonal and malignant disease, health-related quality of life, and performance score.

MAIN RESULTS

We identified three trials that met the inclusion criteria. None of these trials was a RCT. 302 participants are included in this review. The three included studies were prospectively conducted and had features consistent with the principle of 'Mendelian randomization' as defined in the present review. All studies had a high risk of bias due to the study design. All studies were conducted more than 10 years ago and may not be applicable to the standard of care of today. Primary and secondary outcome data showed no statistically significant difference between treatment groups. We present results for first-line allogeneic hematopoietic stem cell transplantation of an HLA-matched sibling donor, which we denote as the MSD-HSCT group, versus first-line treatment with ciclosporin and/or antithymocyte or antilymphocyte globulin, which we denote as the immunosuppressive therapy group in the following section.The pooled hazard ratio for overall mortality for the MSD-HSCT group versus the immunosuppressive therapy group was 0.95 (95% confidence interval 0.43 to 2.12, P = 0.90, low quality evidence). Therefore, overall mortality was not statistically significantly different between the groups. Treatment-related mortality ranged from 20% to 42% for the MSD-HSCT group and was not reported for the immunosuppressive therapy group (very low quality evidence). The authors reported graft failure from 3% to 16% for the MSD-HSCT group and GVHD from 26% to 51% (both endpoints not applicable for the immunosuppressive therapy group, very low quality evidence). The authors did not report any data on response and relapse for the MSD-HSCT group. For the immunosuppressive therapy group, the studies reported no response from 15% (not time point stated) to 64% (three months) and relapse in one of eight responders after immunosuppressive therapy at 5.5 years (very low quality evidence). The authors reported secondary clonal disease or malignancies for the MSD-HSCT group versus the immunosuppressive therapy group in 1 of 34 versus 0 of 22 patients in one study and in 0 of 28 versus 4 of 86 patients in the other study (low quality evidence). None of the included studies addressed health-related quality of life. The percentage of the evaluated patients with a Karnofsky performance status score in the range of 71% to 100% was 92% in the MSD-HSCT group and 46% in the immunosuppressive therapy group.

AUTHORS' CONCLUSIONS

There are insufficient and biased data that do not allow any conclusions to be made about the comparative effectiveness of first-line allogeneic hematopoietic stem cell transplantation of an HLA-matched sibling donor and first-line treatment with ciclosporin and/or antithymocyte or antilymphocyte globulin (as first-line immunosuppressive therapy). We are unable to make firm recommendations regarding the choice of intervention for treatment of acquired severe aplastic anemia.

Comparison of unrelated cord blood transplantation and HLA-mismatched unrelated bone marrow transplantation for adults with leukemia

Recent advances in unrelated cord blood transplantation (UCBT) and high-resolution typing of human leukocyte antigen (HLA) from an unrelated donor have increased choices in alternative donor/stem cell source selection. We assessed HLA-mismatched locus-specific comparison of the outcomes of 351 single-unit UCB and 1,028 unrelated bone marrow (UBM) adult recipients 16 years old or older at the time of transplantation who received first stem cell transplantation with myeloablative conditioning for acute leukemia or myelodysplastic syndromes. With adjusted analyses, HLA 0 to 2 mismatched UCBT showed similar overall mortality (relative risk [RR] = 0.85, 95% confidence interval [CI], 0.68-1.06; P = .149) compared with that of single-HLA-DRB1-mismatched UBMT. UCBT showed inferior neutrophil recovery (RR = 0.50, 95% CI, 0.42-0.60; P < .001), lower risk of acute graft-versus-host disease (RR = 0.55, 95% CI, 0.42-0.72; P < .001), and lower risk of transplantation-related mortality (RR = 0.68, 95% CI, 0.50-0.92; P = .011) compared with single-HLA-DRB1-mismatched UBMT. No significant difference was observed for risk of relapse (RR = 1.28, 95% CI, 0.93-1.76; P = .125). HLA 0 to 2 antigen-mismatched UCBT is a reasonable second alternative donor/stem cell source with a survival outcome similar to that of single-HLA-DRB1-mismatched or other 7 of 8 UBMT.

Clinical effect of reduced-intensity conditioning regimen containing antithymocyte globulin for hematopoietic cell transplantation from unrelated-donors

The impact of reduced-intensity conditioning (RIC) on the outcomes of hematopoietic cell transplantation (HCT) from unrelated -donors (UD) remains to be determined. We therefore assessed 128 patients, aged 16 to 66 years, with acute leukemia (n = 105) or myelodysplastic syndrome (n = 23) in a UD-HCT trial using RIC with busulfan, fludarabine, and antithymocyte globulin. Patients were transplanted with unmanipulated bone marrow (BM, n = 41) or mobilized peripheral blood mononuclear cells (M-PB, n = 87) and received cyclosporine and methotrexate for graft-versus-host disease (GVHD) prophylaxis. After a median follow-up of 26.7 months (range, 5.9-70.7 months) in surviving patients, 19 patients had died without progression/recurrence of underlying disease, giving a cumulative incidence of transplantation-related mortality (TRM) of 17% (95% confidence interval, 11%-27%; 1-year TRM, 14%). Graft failure (n = 7) and infections (n = 5) were the most common causes of TRM. Only three patients died due to GVHD (acute, one; chronic, two). Graft failure, which occurred in eight patients, showed a significant correlation with graft source (BM, 6/41 vs. M-PB, 2/87; P = 0.009). Donor-patient HLA-disparity did not correlate with GVHD, 1-year TRM, and graft failure. RIC containing antithymocyte globulin led to decreased GVHD-associated, as well as overall, TRM after UD-HCT.

A prospective dose-finding trial using a modified continual reassessment method for optimization of fludarabine plus melphalan conditioning for marrow transplantation from unrelated donors in patients with hematopoietic malignancies

BACKGROUND

Because of the less graft-facilitating effect by bone marrow (BM), we need to assess a dosage of conditioning more accurately particularly in combination with reduced-intensity conditioning. Thus we examined that modified continual reassessment method (mCRM) is applicable for deciding appropriate conditioning of allogeneic BM transplantation.

PATIENTS AND METHODS

The conditioning regimen consisted of i.v. fludarabine (125 mg/m2) plus an examination dose of i.v. melphalan. The primary endpoint was a donor-type T-cell chimerism at day 28 with successful engraftment defined as >90% donor cells. Five patients per dose level were planned to be accrued and chimerism data were used to determine the next dose.

RESULTS

Seventeen patients were enrolled at doses between 130 and 160 mg/m2. The dose was changed from 160 to 130 mg/m(2) (second level) after five full-donor chimerisms. With one patient of 0% chimera in the second level, the dose was increased to 135 mg/m2 (third level). Following five full-donor chimerisms in the third level, the study was complete as projected.

CONCLUSIONS

mCRM was shown to be a relevant method for dose-finding of conditioning regimen. The melphalan dose of 135 mg/m2 was determined as the recommended phase II dose to induce initial full-donor chimerism.

Disease-specific analyses of unrelated cord blood transplantation compared with unrelated bone marrow transplantation in adult patients with acute leukemia

We made a disease-specific comparison of unrelated cord blood (CB) recipients and human leukocyte antigen allele-matched unrelated bone marrow (BM) recipients among 484 patients with acute myeloid leukemia (AML; 173 CB and 311 BM) and 336 patients with acute lymphoblastic leukemia (ALL; 114 CB and 222 BM) who received myeloablative transplantations. In multivariate analyses, among AML cases, lower overall survival (hazard ratio [HR]=1.5; 95% confidence interval [CI], 1.0-2.0, P= .028) and leukemia-free survival (HR=1.5; 95% CI, 1.1-2.0, P= .012) were observed in CB recipients. The relapse rate did not differ between the 2 groups of AML (HR=1.2; 95% CI, 0.8-1.9, P= .38); however, the treatment-related mortality rate showed higher trend in CB recipients (HR=1.5; 95% CI, 1.0-2.3, P= .085). In ALL, there was no significant difference between the groups for relapse (HR=1.4, 95% CI, 0.8-2.4, P= .19) and treatment-related mortality (HR=1.0; 95% CI, 0.6-1.7, P= .98), which contributed to similar overall survival (HR=1.1; 95% CI, 0.7-1.6, P= .78) and leukemia-free survival (HR=1.2; 95% CI, 0.9-1.8, P= .28). Matched or mismatched single-unit CB is a favorable alternative stem cell source for patients without a human leukocyte antigen-matched related or unrelated donor. For patients with AML, decreasing mortality, especially in the early phase of transplantation, is required to improve the outcome for CB recipients.

Unification of hematopoietic stem cell transplantation registries in Japan and establishment of the TRUMP System

There are 4 registries of hematopoietic cell transplantation in Japan; the Japan Society for Hematopoietic Cell Transplantation (JSHCT), Japanese Society of Pediatric Hematology, Japan Marrow Donor Program, and Japan Cord Blood Bank Network; each play an important role in society by reporting the number and outcomes of transplantations and contributing new findings obtained from studies on individual topics. However, there have been a number of issues with the difficulty of analyzing data in overlapping registries and multiple databases at centers affiliated with each of the 4 registry organizations. JSHCT was pivotal in orchestrating the computerization and unification of hematopoietic stem cell transplantation registries for the purpose of resolving these issues and providing a more accurate awareness of hematopoietic stem cell transplantations being performed in Japan. JSHCT played a central role in developing the "Transplant Registry Unified Management Program (TRUMP)" to enable transplantation institutes to manage patient information with emphases on convenience to institutes, safety of patient information, and quality of data management. While enhancing domestic registries, the program seeks to coordinate with other hematopoietic cell transplantation registries around the world to contribute to the development of registries throughout Asia.

Effects of HLA allele and killer immunoglobulin-like receptor ligand matching on clinical outcome in leukemia patients undergoing transplantation with T-cell-replete marrow from an unrelated donor

The responsible human leukocyte antigen (HLA) locus and the role of killer immunoglobulin-like receptor (KIR) ligand matching on transplantation outcome were simultaneously identified by multivariate analysis in 1790 patients with leukemia who underwent transplantation with T-cell-replete marrow from an unrelated donor (UR-BMT) through the Japan Marrow Donor Program. The graft-versus-leukemia (GVL) effect depended on leukemia cell type. HLA-C mismatch reduced the relapse rate in acute lymphoblastic leukemia (ALL) (hazard ratio [HR] = 0.47; P = .003), and HLA-DPB1 mismatch reduced it in chronic myeloid leukemia (CML) (HR = 0.35; P < .001). In contrast, KIR2DL ligand mismatch in the graft-versus-host (GVH) direction (KIR-L-MM-G) increased in ALL (HR = 2.55; P = .017). An increased rejection rate was observed in KIR2DL ligand mismatch in the host-versus-graft direction (HR = 4.39; P = .012). Acute GVH disease (GVHD) was increased not only in the mismatch of HLA-A, -B, -C, and -DPB1, but also in KIR-L-MM-G. As a whole, the mismatch of HLA-A, -B, and -DQB1 locus and KIR-L-MM-G resulted in increased mortality. In conclusion, not only the mismatch of HLA-C and -DPB1, but also KIR-L-MM-G affected leukemia relapse, which should be considered based on leukemia cell type. Furthermore, KIR-L-MM induced adverse effects on acute GVHD (aGVHD) and rejection, and brought no survival benefits to patients with T-cell-replete UR-BMT.

High-risk HLA allele mismatch combinations responsible for severe acute graft-versus-host disease and implication for its molecular mechanism

In allogenic hematopoietic stem-cell transplantation, an effect of HLA locus mismatch in allele level on clinical outcome has been clarified. However, the effect of each HLA allele mismatch combination is little known, and its molecular mechanism to induce acute graft-versus-host disease (aGVHD) remains to be elucidated. A total of 5210 donor-patient pairs who underwent transplantation through Japan Marrow Donor Program were analyzed. All HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1 alleles were retrospectively typed in all pairs. The impacts of the HLA allele mismatch combinations and amino acid substitution positions in 6 HLA loci on severe aGVHD were analyzed. A total of 15 significant high-risk HLA allele mismatch combinations and 1 HLA-DRB1-DQB1 linked mismatch combinations (high-risk mismatch) for severe aGVHD were identified, and the number of high-risk mismatches was highly associated with the occurrence of severe aGVHD regardless of the presence of mismatch combinations other than high-risk mismatch. Furthermore, 6 specific amino acid substitution positions in HLA class I were identified as those responsible for severe aGVHD. These findings provide evidence to elucidate the mechanism of aGVHD on the basis of HLA molecule. Furthermore, the identification of high-risk mismatch, that is, nonpermissive mismatch, would be beneficial for the selection of a suitable donor.

Chronic graft-versus-host disease after allogeneic bone marrow transplantation from an unrelated donor: incidence, risk factors and association with relapse. A report from the Japan Marrow Donor Program

Chronic graft-versus-host disease (GVHD) remains the major cause of late morbidity and mortality after allogeneic stem cell transplantation. We retrospectively analysed 2937 patients who underwent bone marrow transplantation from an unrelated donor (UR-BMT) facilitated by the Japan Marrow Donor Program (JMDP) and survived beyond day 100 after transplantation. The cumulative incidence of chronic GVHD (limited + extensive) or extensive chronic GVHD at 5 years post-transplant was 45.8% and 28.2%, respectively. On multivariate analysis, seven variables predicting chronic GVHD were identified: recipient age over 20 years, donor age over 30 years, primary diagnosis of chronic myeloid leukaemia, human leucocyte antigen (HLA)-A or -B mismatch, total body irradiation-containing regimen, platelet count not having reached 50 x 10(9)/l by day 100, and prior acute GVHD. Among 2609 patients with haematological malignancy, overall survival was significantly higher in patients with limited chronic GVHD but lower in patients with extensive chronic GVHD compared with those without chronic GVHD. The cumulative incidence of relapse among patients with limited or extensive chronic GVHD was significantly lower than that among patients without chronic GVHD. Our results suggest that limited chronic GVHD provides a survival benefit to patients with haematological malignancies by reducing the risk of relapse without increasing the risk of death from chronic GVHD.

Impact of cytogenetics on outcome of matched unrelated donor hematopoietic stem cell transplantation for acute myeloid leukemia in first or second complete remission

We compared the treatment-related mortality, relapse rate, disease-free survival (DFS), and overall survival (OS) by cytogenetic risk group of 261 patients with acute myeloid leukemia in first complete remission (CR1) and 299 patients in CR2 in undergoing matched unrelated donor hematopoietic stem cell transplantation (HSCT). For patients in first CR, the DFS and OS at 5 years were similar for the favorable, intermediate, and unfavorable risk groups at 29% (95% confidence interval [CI], 8%-56%) and 30% (22%-38%); 27% (19%-39%) and 29% (8%-56%); and 30% (95% CI, 22%-38%) and 30% (95% CI, 20%-41%), respectively. For patients in second CR, the DFS and OS at 5 years were 42% (95% CI, 33%-52%) and 35% (95% CI, 28%-43%); 38% (95% CI, 23%-54%) and 45% (95% CI, 35%-55%); and 37% (95% CI, 30%-45%) and 36% (95% CI, 21%-53%), respectively. Cytogenetics had little influence on the overall outcome for patients in first CR. In second CR, outcome was modestly, but not significantly, better for patients with favorable cytogenetics. The graft-versus-leukemia effect appeared effective, even in patients with unfavorable cytogenetics. However, treatment-related mortality was high. Matched unrelated donor HSCT should be considered for all patients with unfavorable cytogenetics who lack a suitable HLA-matched sibling donor.

Reduced dose of foscarnet as preemptive therapy for cytomegalovirus infection following reduced-intensity cord blood transplantation

Although foscarnet is a promising alternative for the treatment of cytomegalovirus (CMV) infection, its toxicity can be significant in patients with advanced age. We retrospectively reviewed medical records of 123 patients (median age of 55; range, 17-79) who received reduced-intensity cord blood transplantation (RI-CBT). Patients preemptively received reduced-dose foscarnet 30 mg/kg twice daily when CMV antigenemia exceeded 10/50,000. Sixty-three patients developed CMV antigenemia on a median of day 34, and 29 received foscarnet preemptively. The median level of CMV antigenemia at the initiation of foscarnet was 30. Median duration of foscarnet administration was 24 days. Adverse effects included electrolyte abnormalities (n=19), renal impairment (n=13), and skin eruption requiring discontinuation of foscarnet (n=1). Preemptive therapy of foscarnet was completed in 18 patients. Seven patients died during foscarnet use without developing CMV disease. The remaining 3 developed CMV enterocolitis 5, 14, and 17 days after initiation of foscarnet. All of them were successfully treated with ganciclovir or foscarnet. Reduced dose of foscarnet is beneficial to control CMV reactivation following RI-CBT; however, it has considerable toxicities in RI-CBT recipients with advanced age. Further studies are warranted to minimize toxicities and identify optimal dosages.

Allogeneic Bone Marrow Transplantation from Unrelated Human T-Cell Leukemia Virus-I–negative Donors for Adult T-Cell Leukemia/Lymphoma: Retrospective Analysis of Data from the Japan Marrow Donor Program

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) from an HLA-matched related donor has been suggested to improve the poor prognosis of adult T-cell leukemia/lymphoma (ATLL). However, the infusion of HTLV-I-infected cells from HTLV-I-positive related donors could lead to the development of donor-derived ATLL under immunosuppressive conditions. Although most ATLL patients lack a suitable HLA-matched related donor and require an HTLV-I-negative unrelated donor, little information is currently available regarding the outcome of unrelated bone marrow transplantation (UBMT) for ATLL. To evaluate the role of UBMT in treating ATLL, we retrospectively analyzed data from 33 patients with ATLL treated by UBMT through the Japan Marrow Donor Program (JMDP). Overall survival (OS), progression-free survival, and cumulative incidence of disease progression and progression-free mortality at 1 year after UBMT were 49.5%, 49.2%, 18.6%, and 32.3%, respectively. Multivariate analysis identified recipient age as an independent prognostic factor for OS (P = .044). Patients age >or=50 years who showed nonremission at transplantation tended to have higher rates of treatment-related mortality. Our observations suggest that UBMT could represent a feasible treatment option for ATLL patients and warrant further investigation based on these risk factors.

Human leukocyte antigen matching estimations in a hypothetical bank of human embryonic stem cell lines in the Japanese population for use in cell transplantation therapy

Human embryonic stem (hES) cell lines are of great potential in cell transplantation therapy. However, recipients of such allogeneic transplants probably need treatment with immunosuppressants. Recently, Taylor et al. [Lancet 2005;366:2019-2025] proposed banking of hES cell lines and estimated the required number of hES cell lines for beneficial human leukocyte antigen (HLA) matching in the U.K. population. Here, we carried out such an estimation in the Japanese population. We calculated the proportion of patients who can find at least one HLA-matched donor at three loci of HLA-A, -B, and -DR. With a bank of hES cell lines from 170 randomly selected donated embryos, 80% of patients were expected to find at least one hES cell line with a single mismatch at one HLA locus or a better match. Furthermore, 80% of patients are expected to find at least one donor with complete matching at the three HLA loci if parthenogenetic homozygous hES cell lines are established from 55 randomly selected donated oocytes. The relatively low ethnic diversity of the Japanese population may have resulted in a high success rate in beneficial matching. Moreover, parthenogenetic hES cell lines can greatly reduce the number required for a higher degree of HLA matching.

Successful engraftment of mismatched unrelated cord blood transplantation following reduced intensity preparative regimen using fludarabine and busulfan

We conducted a pilot study to evaluate the feasibility of reduced-intensity cord blood transplantation (RI-CBT) using a non-total body irradiation (TBI) regimen in adult patients with advanced hematologic malignancies. Seventeen patients with a median age of 58 years (range, 38-74) underwent RI-CBT at Tsukuba Memorial Hospital between April 2004 and November 2005. Preparative regimens were fludarabine 30 mg/m(2) for 6 days, and busulfan 4 mg/kg for 2 days. Tacrolimus was used for prophylaxis of graft-vs-host disease (GVHD). Median numbers of infused total nucleated were 2.6 x 10(7)/kg (range, 2.0-3.3). HLA disparity was found in 2/6 antigens (n=16) and 1/6 antigens (n=1). Underlying diseases progressed despite preparative regimens in four patients. Of the remaining 13 patients, nine patients achieved engraftment at a median of day 18 (range, 17-28). Six of the nine patients with engraftment achieved complete donor-type chimerism by day 100. Six patients were alive in remission at median follow-up of 13.1 months (range, 1.0-19.0). This study demonstrated the feasibility of RI-CBT using a non-TBI regimen in adults. When disease progression is controlled by the preparative regimen, RI-CBT carries a clinically significant graft-vs-tumor effect. Further studies are required to identify patients who benefit from this regimen.

Mismatch of minor histocompatibility antigen contributes to a graft-versus-leukemia effect rather than to acute GVHD, resulting in long-term survival after HLA-identical stem cell transplantation in Japan

We determined the alleles of five polymorphic molecules including HA-1 and four adhesion molecules for 106 patients transplanted with HLA-identical stem cell grafts and investigated the association of mismatches as correlates of relapse and graft-versus-host disease (GVHD). All 106 recipients underwent stem cell transplantation (SCT) after myeloablative conditioning between 1985 and 2002. Risk status of disease at SCT was standard (n=63) and high (n=42). After SCT, 36, 49 and 33 developed acute GVHD, chronic GVHD and relapsed, respectively. Our patients relapsed at rates of 16.7 and 38.6% with one or more and without incompatibilities (P=0.013). The relapse rates of patients with CD62L, CD31 codon 563, CD31 codon 125, HA-1 and CD49b incompatibilities were 5.9, 11.8, 15.4, 16.0 and 33.3%, respectively. The frequency of acute GVHD did not differ regardless of incompatibilities. In standard-risk group, the accumulated relapse rates of 19 and 44 patients with and without minor histocompatibility antigen incompatibility were 22% and unexpectedly 66%, respectively (P=0.02). The probability of 12-year survival was 88% in the former and 66% in the latter patients (P=0.03). Our data suggest that incompatibility of CD62L, CD31 codon 563 and CD31 codon 125 contributes to a graft-versus-leukemia effect rather than to GVHD, resulting in prolonged survival after HLA-identical SCT.

Optimization of conditioning for marrow transplantation from unrelated donors for patients with aplastic anemia after failure of immunosuppressive therapy

In 87 patients with aplastic anemia who failed to respond to immunosuppressive treatment, we determined the minimal dose of total body irradiation (TBI) required when added to antithymocyte globulin (ATG, 30 mg/kg x 3) plus cyclophosphamide (CY, 50 mg/kg x 4) to achieve engraftment of unrelated donor marrow. TBI was started at 3 x 200 cGy, to be escalated or deescalated in steps of 200 cGy depending on graft failure or toxicity. Patients were aged 1.3 to 53.5 years (median, 18.6 years). The interval from diagnosis to transplantation was 3 to 328 months (median, 14.6 months). Donors were HLA-A, -B, -C, -DR, and -DQ identical for 62 patients, and nonidentical for 1 to 3 HLA loci at the antigen or allele level for 25. The dose-limiting toxicity was diffuse pulmonary injury. The optimum TBI dose was 1 x 200 cGy. Nine patients did not tolerate ATG and were prepared with CY + TBI. Graft failure occurred in 5% of patients. With a median follow-up of 7 years, 38 (61%) of 62 HLA-identical, and 10 (40%) of 25 HLA-nonidentical transplant recipients are surviving. The highest survival rate with HLA-identical transplants was observed at 200 cGy TBI. Thus, low-dose TBI + CY + ATG conditioning resulted in excellent outcome of unrelated transplants in patients with aplastic anemia who had received multiple transfusions.

Stable Engraftment after a Conditioning Regimen with Fludarabine and Melphalan for Bone Marrow Transplantation from an Unrelated Donor

Graft failure and nonrelapse mortality (NRM) are major obstacles after the first unrelated-donor bone marrow transplantation (UD-BMT) with reduced-intensity conditioning. We evaluated UD-BMT with fludarabine (5 x 25 mg/m2) and melphalan (2 x 90 mg/m2) treatment combined with short-term methotrexate and tacrolimus (n = 20) or cyclosporine (n = 2) therapy for 22 patients with hematologic malignancies who were ineligible for conventional conditioning. Only 9 patients were in remission at transplantation. Seventeen patients underwent HLA-matched or DRB1 allele-mismatched transplantation, and 5 patients underwent HLA-A allele-mismatched or serologically HLA-DR-mismatched transplantation. Regimen-related toxicities were tolerable, although transient oral mucositis, hepatobiliary enzyme elevation, and diarrhea were observed frequently. All evaluable patients achieved sustained neutrophil engraftment, and all patients tested showed complete donor chimerism on day 28. With a median follow-up of 16 months, NRM and overall survival rates at 1 year were 19% and 81%, respectively, among the patients who underwent HLA-matched or DRB1 allele-mismatched transplantation. Acute graft-versus-host disease (GVHD) of grades II to IV occurred in 26% of the patients. The cumulative incidence of chronic GVHD was 44%. Despite the small number of patients and the short follow-up period, this reduced-intensity regimen enabled satisfactory engraftment and achievement of rapid complete donor chimerism with tolerable toxicities in the patients, including those who underwent HLA-mismatched UD-BMT.

Fludarabine, cyclophosphamide and anti-thymocyte globulin for alternative donor transplants in acquired severe aplastic anemia: a report from the EBMT-SAA Working Party

We have developed a reduced-intensity conditioning regimen for patients with severe aplastic anemia (SAA) undergoing alternative donor transplants, which includes fludarabine (120 mg/m(2)), cyclophosphamide (1,200 mg/m(2)) and antithymocyte globulin (7.5 mg/kg). Graft-versus-host disease (GvHD) prophylaxis consisted of cyclosporine and methotrexate. We have enrolled 38 SAA patients in this trial: median age of 14 (3-37) years, transplanted from unrelated (n=33) or family mismatched (n=5) donors, with unmanipulated marrow (n=36) or peripheral blood (n=2). Seven patients (18%) had evidence of graft failure, 11% developed grade II-III acute GvHD and 27% developed chronic GvHD. The actuarial 2-year survival is 73%, with a median follow-up of 621 days. Younger patients (<or=14 years) had a lower risk of rejection (5%) and improved actuarial survival (84%). Causes of death were infections (n=3), graft failure (n=2), Epstein-Barr virus lymphoma (n=2) and hemorrhage (n=2). In conclusion, the actuarial 2-year survival is encouraging in young SAA patients receiving a radiation-free conditioning regimen. The significant risk of graft failure in patients 15 years or older may require modification of the conditioning regimen in adults.

Morphology of the bone marrow after stem cell transplantation

In many haematological conditions the only curative option is stem cell (SCT) or bone marrow (BM) transplantation. Little information exists about BM morphology following non-ablative engraftment. During the pretransplantation period and depending on the kind of pretreatment, there may be hypoplasia, residual disease and varying degrees of fibrosis. In the post-transplantation period, after 1-3 weeks of transfusion-dependent pancytopenia, the first signs of successful engraftment are indicated by the recurrence of neutrophils, monocytes and erythrocytes in the peripheral blood. In the BM there is slow regeneration of erythropoiesis, followed by the other lineages of haematopoiesis and increase in reticulin fibres or even a resolution of fibrosis. Diagnostic problems arise when neoplastic lympho- or haematopoiesis are maintained following transplantation. Moreover, there may be a significant graft versus tumour response reaction or an already relapsing disease needing aggressive treatment. On the other hand, a conspicuous dyshaematopoiesis should not be mistaken as representing a myelodysplastic syndrome. The presence of granulomas being treatment-related or a manifestation of intercurrent granulomatous disease has to be considered. More advanced knowledge of the histological features of regenerating BM will certainly aid the recognition of relapsing disease and is needed for the adequate reporting of post-transplant alterations associated with a successful or failing engraftment.

Intestinal thrombotic microangiopathy following reduced-intensity umbilical cord blood transplantation

Thrombotic microangiopathy (TMA) is a significant complication after hematopoietic stem-cell transplantation (HSCT); however, there is little information on it following reduced-intensity cord blood transplantation (RI-CBT). We reviewed the medical records of 123 adult patients who received RI-CBT at Toranomon Hospital between January 2002 and August 2004. TMA was diagnosed in seven patients based on intestinal biopsy (n = 6) or autopsy results (n = 1). While these patients showed some clinical symptoms such as diarrhea and/or abdominal pain, mental status alterations or neurological disorders were not observed in any of them. Laboratory results were mostly normal at the onset of TMA; >2% fragmented erythrocytes (n = 1), <10 mg/dl haptoglobin (n = 1), and >200 IU/dl lactic dehydrogenase (LD) (n = 4). On endoscopic examination, TMA lesions, consisting of ulcers, erosions, and diffuse exfoliation, were distributed spottily from terminal ileum to rectum. Intestinal graft-versus-host disease (GVHD) and cytomegalovirus (CMV) colitis were confirmed in five and four patients, respectively. With therapeutic measures including supportive care (n = 4), fresh frozen plasma (n = 1), and a reduction of immunosuppressive agents (n = 1), TMA improved in four patients. The present study demonstrates that intestinal TMA is a significant complication after RI-CBT. Since conventional diagnostic criteria can overlook TMA, its diagnosis requires careful examination of the gastrointestinal tract using endoscopy with biopsy.

Effect of Conditioning Regimen on the Outcome of Bone Marrow Transplantation from an Unrelated Donor

Little information is available regarding the effect of the conditioning regimen on the outcome of bone marrow transplantation (BMT) from an unrelated donor. Therefore, we retrospectively compared the outcome after a cyclophosphamide/total body irradiation (Cy-TBI) regimen, an intensified Cy-TBI regimen (Cy-TBI+), a busulfan and cyclophosphamide (Bu-Cy) regimen, and a Bu-Cy regimen with total lymphoid irradiation (Bu-Cy-TLI). Clinical data of 1875 adult patients who underwent unmanipulated unrelated BMT for leukemia or myelodysplastic syndrome by using 1 of the 4 regimens between 1993 and 2002 were extracted from the database of the Japan Marrow Donor Program. The effect of the conditioning regimen was adjusted for other independent significant factors by multivariate analyses. The Cy-TBI regimen was significantly better than the Bu-Cy regimen with regard to the incidence of engraftment failure (odds ratio, 2.49; P = .046) and overall survival (relative risk [RR], 1.31; P = .050). The Bu-Cy-TLI regimen decreased relapse (RR, 0.13; P = .039) but increased nonrelapse mortality (RR, 1.89; P = .0061). The Cy-TBI+ regimen resulted in increased nonrelapse mortality (RR, 1.48; P = .0003) and inferior survival (RR, 1.45; P < .0001). The results of this retrospective study suggested that the Cy-TBI regimen was superior to other regimens in unrelated BMT.

Bloodstream infection after umbilical cord blood transplantation using reduced-intensity stem cell transplantation for adult patients

Bloodstream infection (BSI) is a significant problem after cord blood transplantation (CBT). However, little information has been reported on BSI after reduced-intensity CBT (RI-CBT). We retrospectively reviewed the medical records of 102 patients. The median age of the patients was 55 years (range, 17-79 years). Preparative regimens comprised fludarabine 125 to 150 mg/m 2 , melphalan 80 to 140 mg/m 2 , or busulfan 8 mg/kg and total body irradiation 2 to 8 Gy. Prophylaxis against graft-versus-host disease comprised cyclosporin or tacrolimus. BSI developed within 100 days of RI-CBT in 32 patients. The cumulative incidence of BSI was 25% at day 30 and 32% at day 100. The median onset was day 15 (range, 1-98 days). Causative organisms included Pseudomonas aeruginosa (n = 12), Staphylococcus epidermidis (n = 11), Staphylococcus aureus (n = 6), Enterococcus faecium (n = 4), Enterococcus faecalis (n = 4), Stenotrophomonas maltophilia (n = 4), and others (n = 7). Of the 32 patients with BSI, 25 (84%) died within 100 days after RI-CBT. BSI was the direct cause of death in 8 patients (25%). Univariate analysis failed to identify any significant risk factors. BSI clearly represents a significant and fatal complication after RI-CBT. Further studies are warranted to determine clinical characteristics, identify patients at high risk of BSI, and establish therapeutic strategies.

Human leukocyte antigen matching in unrelated donor hematopoietic cell transplantation

Hematopoietic cell transplantation (HCT) from unrelated donors is a curative therapy for many malignant and nonmalignant blood disorders. The success of unrelated HCT is influenced by the degree of human leukocyte antigen (HLA) compatibility between the donor and patient. When donor matching for HLA alleles is feasible, overall transplant outcome is superior. The presence of donor-recipient mismatching is associated with increased risk of post-transplant complications including graft rejection, acute and chronic graft-versus-host disease (GVHD), and mortality; these risks are increased with multiple HLA mismatches. For the majority of patients who lack HLA-matched unrelated donors, current research is focused on the identification of permissible HLA mismatches. The influence of nongenetic factors on the tolerability of HLA mismatching has recently become evident, demonstrating a need for the integration of both genetic and nongenetic variables in donor selection.

Human leukocyte antigen haploidentical hematopoietic stem cell transplantation: Indications and tentative outcomes in Japan

The stem cell banking system in Japan by the Japan Marrow Donor Program (JMDP) and Japan Cord Blood Bank Network (JCBBN) has provided increased opportunities for patients who might benefit from stem cell transplant from allogeneic sources but who lack human leukocyte antigen (HLA)-matched related donors. Nevertheless, most patients probably do not undergo transplantation because of the absence of suitable stem cell sources. To fulfill this potential need, the outcomes of transplants from HLA-mismatched relatives with or without T-cell depletion were retrospectively analyzed: the rates of engraftment and survival were insufficient in transplants with T-cell depletion, and the actual increase in transplantable donor numbers was small because only a single locus mismatched donor was the realistic choice in those without T-cell depletion. Since prophylaxis with tacrolimus reduced the incidence of grade I-IV acute graft-versus-host disease (GVHD) in HLA class I allele mismatched unrelated donors, we studied transplantation from HLA one haploidentical family donors who showed microchimerism of noninherited maternal antigens, without T-cell depletion but with tacrolimus prophylaxis. The rates of engraftment and survival in this circumstance were similar to those obtained with transplantation from HLA-matched sibling donors.

Efficacy and safety of imatinib mesylate for patients in the first chronic phase of chronic myeloid leukemia: results of a Japanese phase II clinical study

Imatinib mesylate is a relatively new drug that targets the BCR-ABL chimeric protein, the molecular basis of chronic myeloid leukemia (CML). A phase II clinical trial in 39 Japanese patients in the first chronic phase of CML was conducted with imatinib mesylate at a dose of 400 mg/day. Hematologic complete response was obtained in 92.3% of the patients, complete cytogenetic response (CR) was obtained in 43.6%, and major partial CR was obtained in 20.5% of the patients. Although 29 of 39 patients required an adjustment of dosing because of grade 3 or 4 adverse events, most of the events were reversible, and 25 of the 29 patients were able to resume therapy. Between day 15 and day 35, grade 3 or 4 neutropenia and/or leukocytopenia occurred in 13 patients, and grade 3 thrombocytopenia occurred in 5 patients. Overall, nonhematologic grade 3 adverse events occurred in 28.2% of the patients. These data support the use of imatinib mesylate as the treatment of choice for chronic-phase CML patients.

Aplastic Anemia: Management of Pediatric Patients

Aplastic anemia is a term describing the common findings of pancytopenia and marrow hypoplasia arising from a variety of disease states, including acquired aplastic anemia and a variety of congenital marrow failure states. The management of children with these disorders has been confounded by difficulties of diagnosis. The availability of molecular testing has assisted in partial resolution of this problem but has raised new issues, such as the potential of genetic predisposition and the management of asymptomatic individuals with molecular markers. Longitudinal data from large cohort studies and disease registries are providing a rational basis for making more informed treatment decisions for children with these disorders. In particular, the ability to subset patients more accurately has improved triage of treatments. Approaches to hematopoietic stem cell transplantation (SCT), using both conventional and alternative donors, are changing rapidly, and the long-term sequelae of newer approaches are not entirely clear. Improved diagnosis and longer survival have fostered an understanding of the multidisciplinary approach necessary to manage both the underlying problems and the significant sequelae of treatment in both acquired and congenital disease.

Successful engraftment after reduced-intensity umbilical cord blood transplantation for adult patients with advanced hematological diseases

PURPOSE

The purpose of this research was to evaluate the feasibility of reduced-intensity unrelated cord-blood transplantation (RI-UCBT) in adult patients with advanced hematological diseases.

EXPERIMENTAL DESIGN

Thirty patients (median age, 58.5 years; range, 20-70 years) with advanced hematological diseases underwent RI-UCBT at Toranomon Hospital between September 2002 and August 2003. Preparative regimen composed of fludarabine 25 mg/m(2) on days -7 to -3, melphalan 80 mg/m(2) on day -2, and 4 Gy total body irradiation on day -1. Graft-versus-host disease prophylaxis was composed of cyclosporin alone.

RESULTS

Twenty-six patients achieved primary neutrophil engraftment after a median of 17.5 days. Median infused total cell dose was 3.1 x 10(7)/kg (range, 2.0-4.3 x 10(7)/kg). Two transplant-related mortalities occurred within 28 days of transplant, and another 2 patients displayed primary graft failure. Cumulative incidence of complete donor chimerism at day 60 was 93%. Grade II-IV acute graft-versus-host disease occurred in 27% of patients, with median onset 36 days. Primary disease recurred in 3 patients, and transplant-related mortality within 100 days was 27%. Estimated 1-year overall survival was 32.7%. Excluding 7 patients with documented infection, 19 patients displayed noninfectious fever before engraftment (median onset, day 9). Manifestations included high-grade fever, eruption, and diarrhea. The symptoms responded well to corticosteroid treatments in 7 of 13 treated patients.

CONCLUSION

This study demonstrated the feasibility of RI-UCBT in adults.

Allogenic stem cell transplantation for nonmalignant disorders using matched unrelated donors

We here report 25 patients with nonmalignant disorders, ie, severe aplastic anemia (SAA, n = 12) or inborn errors of metabolism (IEM, n = 13), who underwent allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated high-resolution typed HLA-A, -B, and -DRbeta1 identical donors. One patient had an HLA-B subtype-mismatched donor. Conditioning for SAA mainly consisted of cyclophosphamide and total body irradiation, and that for IEM consisted of busulfan and cyclophosphamide. All patients received antithymocyte globulin during conditioning. After HSCT, they were given cyclosporine combined with methotrexate for immunosuppression. Two patients rejected their grafts: 1 died of pneumonia, and the other was successfully regrafted. The cumulative incidence of acute graft-versus-host disease grades II to IV was 24%, whereas chronic graft-versus-host disease occurred in 21%. The 5-year survival rates were 83% in the SAA group and 85% in those with IEM. We conclude that HSCT with HLA-A, -B, and -DRbeta1 genomically matched unrelated donors in combination with antithymocyte globulin in the conditioning regimen gives encouraging results in patients with SAA or IEM.

Association of polymorphic MHC microsatellites with GVHD, survival, and leukemia relapse in unrelated hematopoietic stem cell transplant donor/recipient pairs matched at five HLA loci

In order to determine whether matching/mismatching for microsatellite polymorphism provides useful information on acute graft-vs-host disease (GVHD), survival, and leukemia relapse in hematopoietic stem cell (HSC) transplantation, we genotyped for polymorphisms at 13 microsatellite loci within the major histocompatibility complex (MHC) of 100 unrelated HSC transplant donor-recipient pairs who were matched at five classical human leukocyte antigen (HLA) loci. A high percentage of allele matching was obtained for five microsatellite loci, DQCARII (96%), MICA (93%), MIB (89%), C1-3-1 (93%), and D6S510 (97%), that are localized within 100 kb of the HLA-DR, HLA-DQ, HLA-B, HLA-C, or HLA-A locus. In contrast, the other eight microsatellites are located farther away from the HLA classical loci and have much lower percentages of allele matching [e.g. tumor necrosis factor a (TNFa) (73%), TNFd (74%), D6S273 (64%), C3-2-11 (46%), C5-3-1 (50%), C5-4-5 (63%), C5-2-7 (68%), and D6S265 (81%)]. Therefore, there were at least eight microsatellite markers with relatively high percentages of mismatches in the donor/recipient pairs with acute or chronic GVHD, poor graft survival, and leukemia relapse. However, there were no statistically significant associations between mismatched donor-recipient pairs at the 13 microsatellite loci and acute or chronic GVHD, graft survival, and leukemia relapse. Nevertheless, allele matching at the microsatellite TNFd locus near the TNFa gene was found by the Fisher's exact double-sided test to be significantly associated with decreased survival in the grade III/IV acute GVHD group. Overall, these results suggest that the matching of microsatellite polymorphisms within the HLA region, especially the ones farthest from the classical HLA loci, was not useful indicator for the outcome of HSC transplantation from unrelated donors. In this regard, the future determination of the genome-wide microsatellite genotypes in HLA-matched donor-recipient pairs, outside the MHC, may be a better possibility for identifying minor histocompatibility genes in linkage disequilibria with microsatellites as potential predictive markers for the occurrence of acute GVHD and survival rate in HSC transplantation.

Limits of HLA mismatching in unrelated hematopoietic cell transplantation

HLA matching between the donor and recipient improves the success of unrelated hematopoietic cell transplantation (HCT). Matched donors are available for only a minority of patients. Further information is needed to evaluate the limits of HLA mismatching. We examined the association of mortality with HLA-A, -B, -C, -DRB1, and -DQB1 mismatching in 948 patients who received a T-replete unrelated HCT for treatment of a marrow disorder. A single HLA allele or antigen mismatch was associated with increased mortality among patients with chronic myeloid leukemia (CML) within 2 years after diagnosis compared to patients with no HLA mismatch, but not among those with more advanced malignancy. In particular, a single HLA-C mismatch conferred increased risk of mortality compared to matches. There was a suggestion for increased mortality with multiple mismatches involving HLA-DQB1 compared to multiple mismatches not involving HLA-DQB1. Donors with a single HLA allele or antigen mismatch may be used for HCT when a fully matched donor is not available for patients with diseases that do not permit time for a lengthy search. Whenever possible, HLA-C mismatches should be avoided for patients with early stage CML, and HLA-DQB1 mismatches should be avoided for patients with multiple mismatches.

Tacrolimus instead of cyclosporine used for prophylaxis against graft-versus-host disease improves outcome after hematopoietic stem cell transplantation from unrelated donors, but not from HLA-identical sibling donors: a nationwide survey conducted in Japan

Despite recent advances, graft-versus-host disease (GVHD) remains the main cause of treatment failure for patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Tacrolimus (FK506) has been increasingly used in place of cyclosporine (CSP), and several studies have shown that FK506 reduces the incidence of acute GVHD more effectively than does CSP. However, no survival benefits have been demonstrated, and no established consensus exists on the choice of these immunosuppressive agents. To compare a CSP-based and an FK506-based regimen, we performed a large-scale retrospective study by using the data of 1935 patients who underwent HSCT from HLA-identical sibling donors (SIB-HSCT) and 777 patients who underwent HSCT from unrelated donors (UD-HSCT). For patients undergoing UD-HSCT, FK506 significantly reduced the risk of acute GVHD and treatment-related mortality (TRM) without an increase in relapse, thus improving overall survival (OS) (hazard ratio (HR): 2.20, 95% confidence interval (CI): 1.60-3.04, P<0.0001 for grade II-IV acute GVHD; HR: 1.81, 95% CI: 1.32-2.48, P=0.0003 for TRM; HR: 1.62, 95% CI: 1.23-2.14, P=0.0007 for OS). This superiority of FK506 was not observed in SIB-HSCT cases. These findings indicate that the use of FK506 instead of CSP for GVHD prophylaxis is beneficial for patients undergoing UD-HSCT.

Cytomegalovirus antigenemia and outcome of patients treated with pre-emptive ganciclovir: retrospective analysis of 241 consecutive patients undergoing allogeneic hematopoietic stem cell transplantation

CMV disease remains a major infectious complication after allogeneic hematopoietic stem cell transplantation (HSCT). To investigate the relationship between CMV antigenemia, treatment with ganciclovir (GCV), and outcome, we retrospectively analyzed 241 consecutive patients at risk for CMV infection who underwent allogeneic HSCT. Antigenemia-guided pre-emptive strategy with GCV was used for all patients. CMV antigenemia developed in 169 patients (70.1%), and CMV disease in 18 patients (7.5%). Multivariate analysis showed that acute GVHD (grades II-IV) was the only risk factor for developing antigenemia, and acute GVHD and advanced age for CMV disease. GCV use, as well as acute GVHD and advanced age, significantly increased the risk for bacterial and fungal infection after engraftment. Those who developed CMV antigenemia had a poorer outcome than those who did not (log-rank, P=0.0269), although the development of CMV disease worsened the outcome with only borderline significance (log-rank, P=0.0526). In conclusion, detection of antigenemia proved to be a poor prognostic factor for HSCT patients, which may be attributed to a combination of factors, including CMV disease itself, the effect of treatment, and a host status that allows for reactivation of CMV. Optimal pre-emptive strategy needs to be determined.

Feasibility of reduced intensity hematopoietic stem cell transplantation from an HLA-matched unrelated donor

To evaluate the feasibility of reduced intensity stem cell transplantation (RIST) with bone marrow from a matched unrelated donor (MUD), we retrospectively investigated 20 patients with hematological disorders who received RIST in the Tokyo SCT consortium from January 2000 to October 2002. The preparative regimens were fludarabine-based (150-180 mg/m(2), n=18) or cladribine-based (0.77 mg/kg, n=2). To enhance engraftment, antithymocyte globulin (ATG) and 4 or 8 Gy total body irradiation (TBI) were added to these regimens in nine and 11 patients, respectively. GVHD prophylaxis was cyclosporine with or without methotrexate. In all, 19 achieved primary engraftment. Three developed graft failure (one primary, two secondary), and five died of treatment-related mortality within 100 days of transplant. Seven of the 19 patients who achieved initial engraftment developed grade II-IV acute GVHD, and seven of 13 patients who survived >100 days developed chronic GVHD. At a median follow-up of 5.5 months, estimated 1-year overall survival was 35%. Compared with a TBI-containing regimen, an ATG-containing regimen was associated with a high risk of graft failure (30 vs 0%, P=0.0737). This study supports the feasibility of RIST from MUD; however, procedure-related toxicities remain significant in its application to patients.

Graft-versus-host disease (GVHD)-specific survival and duration of systemic immunosuppressive treatment in patients who developed chronic GVHD following allogeneic haematopoietic cell transplantation

We investigated graft-versus-host disease (GVHD)-specific survival (GSS) and the duration of systemic immunosuppressive treatment (IST) in 82 patients who developed chronic GVHD following allogeneic haematopoietic cell transplantation (HCT). These two major study endpoints were calculated using the Kaplan-Meier method. Deaths solely due to the relapse of underlying disease or accidental deaths were censored at the time of occurrence for the analysis of GSS. The probability of GSS at 5 years was 74.2%. The median duration of systemic IST for chronic GVHD was 272 d (range: 7-1450), and the probability of withdrawal of systemic IST at 1, 2 and 3 years was 67.3%, 82.4% and 89.0% respectively. Analysis based on a multivariate model showed that a diagnosis other than leukaemia or myelodysplastic syndrome (P = 0.049), prior occurrence of grade III-IV acute GVHD (P = 0.021), onset of chronic GVHD before d 120 (P = 0.013), serum alkaline phosphatase over 120 IU/l (P = 0.034), and serum bilirubin over 34.2 micromol/l (P = 0.015) were independent adverse prognostic factors for GSS. Prior occurrence of grade III-IV acute GVHD significantly influenced the duration of systemic IST (P = 0.048). In conclusion, analyses of GSS and the duration of systemic IST will allow patients with different outcomes to be stratified for appropriate treatment application and will provide important parameters in prospective trials for the treatment of chronic GVHD.

The kinetics of immune reconstitution after cord blood transplantation and selected CD34+ stem cell transplantation in children: comparison with bone marrow transplantation

The present study compares immune reconstitution after allogeneic cord blood transplantation (CBT) and CD34+ stem cell transplantation (CD34-SCT) with that after bone marrow transplantation (BMT). Eighty-eight children who underwent CBT (20 patients), BMT (58), and CD34-SCT (10) were enrolled, and lymphocytes and T-, B-, and natural killer-lymphocyte subsets were monitored for more than 5 years after transplantation. CBT recipients showed significant ircreases in (1) total lymphocyte counts (P < .001), (2) CD4+/CD8+ cell ratios (P < .01), (3) CD4+ and CD4+CD45RA+ cells (P < .001), (4) CD8+CD11b+ cells (P < .001), and (5) CD19+ and CD19+CD5+ cells (P < .0001) and marked decreases in the frequencies of CD8+ and CD8+CD11b- cells (P < .0001). CD34-SCT recipients showed lower lymphocyte counts in the first 6 months and an emergence of lymphocyte and CD4+CD45RA+ cells at approximately 9 months and 1 year. Both CBT and CD34-SCT recipients showed increased frequencies of CD56+ cells at 1 month (CD34-SCT versus BMT, P < .001) but decreased frequencies after 6 months (CBT versus BMT, P < .001). Lymphoproliferative responses to exogenous interleukin 2 were constantly lower in CBT and CD34-SCT recipients than in BMT recipients. These results suggest that the delay in immune reconstitution after CBT in the early phase was mainly qualitative and related to the immaturity of cells, whereas the delay in CD34-SCT was mainly quantitative in the first several months.

Successful bone marrow plus cord blood stem cell transplantation in a girl who developed myelodysplastic syndrome from hepatitis-associated aplastic anemia treated with long-term immunosuppressants and growth factors

A 9-year-old girl who had hepatitis-associated aplastic anemia was treated intermittently with methylprednisolone pulse therapy and growth factors (granulocyte-colony stimulating factor (G-CSF), recombinant human erythropoietin (rhEpo) and cyclosporin A (CyA) for over two years. At this time, there was hematological improvement, but chromosome analysis revealed monosomy 7. After six months, there was progression to myelodysplastic syndrome (MDS) (stage in refractory anemia of excess blasts (RAEB)) with monosomy 7, monosomy 6, marker chromosome and with hematological deterioration. She received bone marrow (1.57 x 10(5) cells kg(-1) (patient body weight)) plus cord blood cell (0.3 x 10(7) cells kg(-1) (patient body weight)) transplantation from her brother, 2 years and 7 months after the diagnosis of hepatitis-associated aplastic anemia. Engraftment was achieved after two weeks, and acute graft-versus-host disease occurred in a mild form after four weeks. Hematological remission has been continuous for 20 months after bone marrow transplantation. Transformation of hepatitis-associated aplastic anemia to MDS with the monosomy 7, monosomy 6 and marker chromosome in this patient was considered to have been related to the administration of high doses of immunosuppressive drugs plus growth factors.

Outcome of 154 patients with severe aplastic anemia who received transplants from unrelated donors: the Japan Marrow Donor Program

We retrospectively analyzed results for 154 patients with acquired severe aplastic anemia who received bone marrow transplants between 1993 and 2000 from unrelated donors identified through the Japan Marrow Donor Program. Patients were aged between 1 and 46 years (median, 17 years). Seventy-nine donor-patient pairs matched at HLA-A, -B, and -DRB1 loci, as shown by DNA typing. Among the 75 mismatched pairs, DNA typing of 63 pairs showed that 51 were mismatched at 1 HLA locus (18 HLA-A, 11 HLA-B, 22 HLA-DRB1) and 12 were mismatched at 2 or more loci. Seventeen patients (11%) experienced either early or late graft rejection. The incidence of grade III/IV acute graft versus host disease and chronic graft versus host disease was 20% (range, 7%-33%) and 30% (range, 12%-48%), respectively. Currently, 99 patients are alive, having survived for 3 to 82 months (median, 29 months) after their transplantations. The probability of overall survival at 5 years was 56% (95% confidence interval, 34%-78%). Multivariate analysis revealed the following unfavorable factors: transplantation more than 3 years after diagnosis (relative risk [RR], 1.86; P =.02), patients older than 20 years (RR, 2.27; P =.03), preconditioning regimen without antithymocyte globulin (RR 2.28; P =.04), and HLA-A or -B locus mismatching as determined by DNA typing. Matching of HLA class I alleles and improvement of preparative regimens should result in improved outcomes in patients with severe aplastic anemia who receive transplants from unrelated donors.

Unrelated donor marrow transplantation for myelodysplastic syndromes: outcome analysis in 510 transplants facilitated by the National Marrow Donor Program

Between April 1988 and July 1998, 510 patients with myelodysplastic syndromes (MDS) underwent unrelated donor bone marrow transplantation (BMT) facilitated by the National Marrow Donor Program. Median age was 38 years (range, <1-62 years). Several conditioning regimens and graft-versus-host disease (GVHD) prophylaxis methods were used, and T-cell depletion was used in 121 patients. Donors were serologically matched for HLA-A, -B, and -DRB1 antigens for 74% of patients. Of 437 patients evaluable for engraftment, 24 (5% cumulative incidence, with 95% confidence interval [CI] of 3%-7%) failed to engraft, and an additional 33 (8% cumulative incidence; 95% CI, 6%-10%) had late graft failure. Grades II to IV GVHD developed in 47% of patients (95% CI, 43%-49%), and limited and extensive chronic GVHD developed at 2 years in 27% (95% CI, 24%-30%). The incidence of relapse at 2 years was 14% (95% CI, 11%-17%). Greater relapse was independently associated with advanced MDS subtype and no acute GVHD. The estimated probability of disease-free survival (DFS) at 2 years was 29% (95% CI, 25%-33%). Improved DFS was independently associated with less advanced MDS subtype, higher cell dose, recipient cytomegalovirus (CMV) seronegativity, shorter interval from diagnosis to transplantation, and transplantation in recent years. Common causes of death were treatment-related complications accounting for 82% of fatalities. The 2-year cumulative incidence of treatment-related mortality (TRM) was 54% (95% CI, 53%-61%). Sixty-nine percent of TRM occurred within the first 100 days, and 93% occurred within the first year of transplantation. Higher TRM was independently associated with older recipient and donor age, HLA mismatch, and recipient CMV seropositivity. This study demonstrates that unrelated donor BMT cures a significant proportion of patients with MDS. TRM is the major problem limiting the success of unrelated donor BMT in MDS. The observations made in this study should facilitate the design of prospective trials aimed at improving the results of unrelated donor stem cell transplantation for MDS.