Current status of hematopoietic stem cell transplantation in the treatment of aplastic anemia / 中国组织工程研究

BACKGROUND: A great progress has been achieved in the allogeneic hematopoietic stem cell transplantation for aplastic anemia. However, graft-versus-host disease and graft failure after transplantation are still the main causes of non-relapse death, which seriously affect the survival of patients. OBJECTIVE: To summarize the current status and progress of allogeneic hematopoietic cell transplantation in the treatment of aplastic anemia. METHODS: The first author retrieved PubMed, CNKI, WanFang and VIP databases for the articles concerning allogeneic hematopoietic stem cell transplantation for aplastic anemia published from January 1990 to September 2019. The keywords were “aplastic anemia, matched sibling donor hematopoietic stem cell transplantation, unrelated donor hematopoietic stem cell transplantation, haploidentical hematopoietic stem cell transplantation, cord blood transplantation” in Chinese and English, respectively. Finally 55 eligible articles were included for result analysis. RESULTS AND CONCLUSION: HLA-matched sibling donor allogeneic hematopoietic stem cell transplantation is the first choice. Unrelated donor hematopoietic stem cell transplantation may be an effective and feasible first-line therapy in pediatric severe aplastic anemia patients with no matched sibling donors. Haploidentical hematopoietic stem cell transplantation and cord blood transplantation can also be important transplantation methods for severe aplastic anemia when lack of HLA-matched donors.

Similar transplant outcomes between haploidentical and unrelated donors after reduced-intensity conditioning with busulfan, fludarabine, and anti-thymocyte globulin in patients with acute leukemia or myelodysplastic syndrome

BACKGROUND: Although T-cell-replete hematopoietic cell transplantation (HCT) from haploidentical donors (HIDs) using anti-thymocyte globulin (ATG) has shown promising outcomes, previous studies often adopted heterogenous graft sources and conditioning.METHODS: We retrospectively compared HCT outcomes from 62 HIDs, 36 partially-matched unrelated donors (PUDs), and 55 matched unrelated donors (MUDs) in patients with acute leukemia or myelodysplastic syndrome using the same graft source of peripheral blood and a reduced intensity conditioning of busulfan, fludarabine, and ATG.RESULTS: The estimates of 3-yr disease-free survival (DFS) and overall survival (OS) rates were not significantly different among the MUD, HID, and PUD groups, at 46%, “41%, and 36%” for the DFS rate (P=0.844), and 55%, 45%, and 45% for the OS rate (P=0.802), respectively. Cumulative incidence of relapse and non-relapse mortality at 3 yr was similar among different donor types. Subsequent multivariable analyses showed that the sex of the patient (male) and a high/very high disease risk index were independently associated with poorer DFS and OS, while the donor type was not.CONCLUSION: T-cell replete HCT from HIDs using an ATG-containing reduced intensity conditioning regimen may be a reasonable option in the absence of matched related donors in patients with acute leukemia or myelodysplastic syndrome.

HLA-10/10 matched unrelated donor versus sibling donor hematopoietic stem cell transplantation for adult acute myeloid leukemia / 中华血液学杂志

Objective@#To evaluate the outcomes of human leukocyte antigen (HLA) matched unrelated donor hematopoietic stem cell transplantation (MUD-HSCT) for adult acute myeloid leukemia (AML) in a single center.@*Methods@#Consecutive adult AML who received MUD-HSCT in our center from January 2008 to April 2017 were studied retrospectively, comparing with patients undergoing matched sibling donor (MSD) -HSCT in the same period. The rates of overall survival (OS) , disease free survival (DFS) , relapse, non-relapse mortality (NRM) , engraftment, acute and chronic graft-versus-host disease (aGVHD and cGVHD) were analyzed.@*Results@#A total of 247 consecutive cases were enrolled, including 46 patients with MUD-HSCT and 201 with MSD-HSCT. All the patients experienced neutrophil engraftment except for one patient who died early in the MSD group, but the median day of engraftment was longer in the MUD group (15.0 vs 14.0, P=0.017) . The accumulative engraftment rate of platelet was comparable between the two groups (93.5%vs 98.0%, P=0.128) . The accumulative incidences of aGVHD (50.0%vs 46.3%, P=0.421) and cGVHD (37.8%vs 43.0%, P=0.581) were not statistically different between the two groups. Compared with the MSD group, the accumulative NRM rate at+36 months after transplantation was significantly higher in the MUD group (22.0%vs 10.4%, P=0.049) , while the relapse rate was not statistical difference (20.5 vs 28.3%, P=0.189) . Both the 3-year OS (61.6%vs 63.3%, P=0.867) and DFS (57.5%vs 61.6%, P=0.760) were comparable between the two groups. Four independent risk factors were confirmed by the multivariate analysis: patient age ≥45 years old, CR2 or NR before transplantation, a history of extramedullary infiltration and the occurrence of grade Ⅲ-Ⅳ aGVHD. No statistical differences were demonstrated in the survival rate between MUD-and MSD-HSCT in different subgroups.@*Conclusions@#The outcomes, such as GVHD, relapse, OS and DFS, were comparable between MUD-and MSD-HSCT for adult AML, but higher incidence of NRM and longer time to neutrophil engraftment in the MUD group. MUD-HSCT is practical and feasible for adult AML who are lack of MSD.

The efficacy and safety of co-transplantation of unrelated donor peripheral blood stem cells combined with umbilical mesenchymal stem cells in patients with refractory severe aplastic anemia-Ⅱ / 中华内科杂志

The efficacy and safety of co-transplantation of unrelated donor peripheral blood stem cells (UD-PBSCs) combined with umbilical cord mesenchymal stem cells (UC-MSCs) in refractory severe aplastic anemia-Ⅱ(RSAA-Ⅱ) were analyzed retrospectively. Fifteen patients with RSAA-Ⅱ underwent UD-PBSCs and UC-MSCs co-transplantation, among whom 14 cases had hematopoietic reconstitution without severe graft versus-host disease (GVHD). The 5-year overall survival rate was 78.57%. Combination of UD-PBSCs and UC-MSCs transplantation could be a safe and effective option for RSAA-Ⅱ.

A comparative study of unrelatedversus matched-sibling donor allogeneic hematopoietic stem cell transplantation for leukemic children / 中华器官移植杂志

Objective To evaluate the efficacy of unrelated donor allogeneic hematopoietic stem cell transplantation (allo-HSCT) for leukemic children .Methods Clinical data of 54 leukemic children undergoing allo-HSCT were retrospectively analyzed from May 2006 to March 2018 .According to the source of donor ,they were divided into matched sibling donor allo-HSCT group (MSD ,n = 27 ) and unrelated donor group (URD ,n= 27) .The clinical outcomes of leukemic children receiving URD allo- HSCT were assessed and those in MSD allo-HSCT group were enrolled as control .Results One patient with refractory AML was not implanted in URD group and the remaining 53 cases were successful in hematopoietic reconstitution .The time of neutrophil and platelet ,the incidence of acute graft-versus-host disease (aGVHD ) , chronic GVHD (cGVHD ) , generalized cGVHD and their transplant-related complications including pulmonary complications ,hemorrhagic cystitis between two groups were not statistically different (P> 0 .05) .The incidence of serious aGVHD ,cytomegalovirus (CMV) and EB virus (EBV) infection was significantly higher in URD group than that in MSD group (P< 0 .05) .The proportion of non-recurrent deaths in URD and MSD groups was 80％ and 31 .3％ respectively and the difference between two groups was statistically significant ( P = 0 .041) .The 3- year disease-free survival rate (DFS) of URD group and MSD group was (52 .9 ± 9 .8 )％ ,(38 .5 ± 8 .7 )％ and the overall 3-year survival rate (OS) was (57 .9 ± 9 .5)％ and (46 .5 ± 9 .7)％ respectively . The inter-group difference was not statistically significant ( P > 0 .05 ) .Conclusions In leukemic children ,although the incidence of complications post URD allo-HSCT is significantly increased , the prognosis is comparable to MSD allo-HSCT .It is a good choice when there is no suitable sibling donor .

Outcomes of alternative donor allogeneic hematopoietic stem cell transplantation for Fanconi anemia:a five cases report / 中华内科杂志

Five patients with Fanconi anemia who received hematopoietic cell transplantation were retrospectively analyzed. The conditioning regimens included fludarabine, cyclophosphamide and anti-thymocyte globulin. Two patients received both bone marrow and peripheral blood stem cells as the source of stem cell grafts from haploidentical matched related donors, while the others received peripheral blood stem cells from unrelated donors.All patients tolerated well and reached hematopoietic reconstitution. One patient died of intracranial infection.During follow-up,4 patients survived independent of transfusion with full donor chimerism.

Interleukin-27:a biomarker for prediction of acute graft-versus-host disease after allogeneic hemato-poietic stem cell transplantation from unrelated donors / 中华微生物学和免疫学杂志

Objective To analyze the predictive value of serum interleukin-27 (IL-27) for acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) from unrelated donors. Methods Serum samples were collected from 72 patients after receiving allo-HSCT from unrelated donors during January to December 2012. Serum samples collected from 70 patients received allo-HSCT in 2013 were used for confirmation. All patients received myeloablative conditioning regimen prior to allo-HSCT. Cyclosporin A (CsA)+mycophenolate mofetil (MMF)+short-term methotrexate (MTX) were used for GVHD prophylaxis. Serum IL-27 levels in patients with aGVHD were measured by ELISA. The pre-dictive value of IL-27 index,defined as the ratio of serum IL-27 level at neutrophil engraftment to that before pre-conditioning regimen, for allogeneic HSCT was retrospectively analyzed. Results Serum IL-27 index was significantly decreased in patients with gradeⅡ-ⅣaGVHD(grade 0-Ⅰ : 1.89±0.68 vs gradeⅡ-Ⅳ :1.26±0.49;P<0.000 1). IL-27 index had good value for grade Ⅱ-Ⅳ aGVHD (AUC=0.782,95% CI:0.675-0.889,P<0.001). Patients with a lower serum IL-27 index (<1.33) were more likely to have a higher cumulative incidence of grade Ⅱ-Ⅳ aGVHD than those with a higher serum IL-27 index (P<0.001). Multivariate analysis confirmed that low IL-27 index was the most significant risk factor for gradeⅡ-Ⅳ aGVHD (HR=4.50,95% CI:2.1-9.8,P<0.01). These findings were consistent with the results found in the serum samples collected in 2013. Conclusion Low IL-27 index could be used to predict the incidence of grade Ⅱ-Ⅳ acute GVHD after allo-HSCT from unrelated donors.

Outcome of unrelated-donor allogeneic hematopoietic cell transplantation for 29 recipients with severe aplastic anemia / 中华器官移植杂志

Objective To assess the effectiveness of unrelated donor (URD) allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the treatment of severe aplastic anemia (SAA),and the difference between URD allo-HSCT and matched sibling donor (MSD) allo-HSCT.Methods According to the source of donors,the SAA patients subject to allo-HSCT were divided into MSD allo-HSCT group (MSD group) and URD allo-HSCT group (URD group) from October 2001 to December 2016 in Henan Cancer Hospital.The efficacy and transplantation related complications were compared between two groups.Results There were no statistically significant differences in hematopoietic reconstitution and graft rejection between two groups.The incidence of grade Ⅱ-Ⅳ acute GVHD and chronic GVHD was higher in the URD group than in the MSD group (30.76％ vs.8.57％,P =0.026;26.92％ vs.5.71％,P =0.021).However,other transplant-related complications including pulmonary complications and hemorrhagic cystitis,incidence of EBV and CMV reactivation and venous occlusive disease showed no significant difference between two groups.The estimated 5-year over survival was (73.6 ± 8.7) ％ in the MSD group and (72.7 ± 9.5) ％ in the URD group (P =0.878).There was no significant difference in 5-year disease-free survival between two groups (73.6 ± 8.7％ vs.70.3 ± 10.2,P =0.668).Conclusion URD-HSCT is a novel treatment approach and could be considered as first-line therapy in selected patients without MSD.

Physicians' preferences and perceptions regarding donor selection in allogeneic stem cell transplantation in Korea when a matched domestic donor is not available

BACKGROUND: A number of alternative donor options exist for patients who fail to find domestic HLA-matched donors for allogeneic hematopoietic stem cell transplantation (allo-HSCT). We assessed physicians' perspectives on allo-HSCT donor selection when a matched domestic donor is not available. METHODS: We administered a questionnaire survey to 55 hematologists (response rate: 28%) who attended the annual spring conference of the Korean Society of Haematology in 2015. The questionnaire contained four clinical allo-HSCT scenarios and the respondents were asked to choose the most preferred donor among the given options. RESULTS: In all four scenarios, the hematologists preferred a matched international donor over partially mismatched unrelated domestic or haplo-matched family donors. The numbers of hematologists who chose a matched international donor (HLA 8/8) in cases of acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, and aplastic anemia were 37 (67.3%), 41 (74.6%), 33 (60.0%), and 36 (65.5%), respectively. The important factors that affected donor selection included “expecting better clinical outcomes (40.5%)” and “lower risk of side effects (23.4%).” The majority of participants (80%) responded that allo-HSCT guidelines for donor selection customized for the Korean setting are necessary. CONCLUSION: Although hematologists still prefer perfectly matched foreign donors when a fully matched domestic allo-HSCT donor is not available, we confirmed that there was variation in their responses. For evidence-based clinical practice, it is necessary to provide further comparative clinical evidence on allo-HSCT from haplo-matched family donors and fully matched unrelated international donors.

HLA Mismatch Allogeneic Blood and Marrow Transplantation / 대한내과학회지

A full haplotype mismatch or mismatched unrelated donor transplantation nowadays are well being focused on, as main alternative donor tools for acute leukemia patients in desperate need of allogeneic blood and marrow transplantation (BMT), the ability to overcome various posttransplant complications by adopting the T-cell replete technique in reality. Increasing numbers of allogeneic BMT in good clinical status are largely because it's the best post-remission therapy especially for many patients with acute leukemias. Due to the problems of unavailable donors at appropriate clinical condition and the process of long duration of donor searching step with relatively much higher cost, some of physicians have indulged in haploidentical BMT rather than mismatched unrelated BMT. Both myeloablative and reduced intensity conditioning regimens for mismatched BMT with T-cell replete or T-cell depletion method have been exploited worldwide. Most of all, Asian countries have experienced lower rates of severe acute and chronic GvHD, graft failure, and impressively low transplant-related mortality with longer follow-up duration. Also, we need many future trials to compare outcomes between these two transplant modalities with cord blood transplant in various diseased patient populations.

Hematopoietic Stem Cell Transplantation in Children with Leukemia: A Single Institution Experience with Respect to Donors

Aim of this study was to compare the outcomes of transplantation by donor source and to help select the best alternative donor in children with leukemia. Donor sources included matched related donor (MRD, n = 35), allele-matched unrelated donor (M-UD, n = 10) or -mismatched (MM)-UD (n = 13) or unrelated umbilical cord blood (UCB, n = 11). UCB group had a significantly higher incidence of grade II-IV acute graft versus host disease (MRD, 11.8%; M-UD, 30.0%; MM-UD, 15.4%, UCB, 54.4%, P = 0.004) but there was no difference in incidence of chronic graft versus host disease between 4 groups. The 5-yr leukemia-free survival (LFS) was 76.7%, 60.0%, 69.2%, and 45.5%, respectively (P = 0.128). MRD group showed higher LFS rate than UCB group (P = 0.022). However, LFS of M-UD and MM-UD together (65.2%) was not different from that of MRD group (76.7%, P = 0.325), or from that of UCB (45.5%, P = 0.190). The relapse incidence at 5 yr was 17.1%, 20.0%, 15.4%, and 0%, respectively (P = 0.460). The 100-day treatment-related mortality was 2.9%, 20.0%, 7.7%, and 36.4%, respectively (P = 0.011). Despite the limitations of small number of patients, unrelated donor transplants including even allele-mismatched ones, seem to be as effective in children with leukemia lacking suitable relative donors. Also, UCB transplant may serve as another possible option in urgent transplants.

Study on the KIR receptor-ligand model in treatment of acute lymphoblastic leukemia / 中华微生物学和免疫学杂志

Objective To investigate the effect of KIR-HLA receptor-ligand model on the unrelated allo-hematopoietic stem cell transplantation (Allo-HSCT) of acute lymphoblastic leukemia (ALL). Methods The KIR genotype of 23 pairs of ALL patients and their HLA-matched unrelated donors obtained from the Database of China Marrow Donor Program. KIR genotype was determined using PCR-SSP. The expression of inhibitory KIR(iKIR) was determined by flow cytometry analysis on recipients after HSCT. Results Among all 23 donor/recipient pairs, 17 donors with KIR2DL2/L3 could find corresponding HLA-Cw1, 3, 7, 8, 12, 14 ligands in their recipients. Six donors with KIR2DL1 could match with HLA-Cw6, 15 in recipients. Sixteen donors with KIR3DL1 could recognize HLA-Bw4 and 12 donors with 3DL2 could find HLA-AI1 in their corresponding recipients, respectively. Ninteen patients were successfully transplanted, and the death rate of transplantation were 33.3% (2/6)and 40.0% (2/5) in KIR receptor-ligand matched model and the graft versus leukemia(HVG) KIR ligand-mismatching pattern. The frequency of acute graft versus host disease(GVHD) was 50.0% and death rate was 12.5% (1/8) in GVH KIR ligand-mismatching. The incidence rate of activated GVHD(aGVHD) was 20.0% in the HVG KIR ligand-mismatching. Five donor/recipient pairs of KIR gene typing were the KIR-haplotype A, 2 donor/recipient pairs with KIR2DS4 * 001/002 were died, 3 donor/recipient pairs with KIR2DS4 * 003-007 were obtained the disease free survival. The expression of CD158a/2DL1 was low when the patient had no aGVHD, but became much higher when aGVHD occurred. The percentage of NK cell of the patients was decreasing since transplantation, but still higher than normal after HSCT[ (23.4 ± 3.8 ) % vs (2.04 ± 0.58) %, P < 0.05 ]. Conclusion Analysis on KIR-HLA gene loci pattern may provide a useful parameter in predicting the clinical outcome of HLA-matched unrelated allogeneic hematopoietic stem cell transplantation for leukemia patients. Moreover, it may help to increase overall survival and disease free survival after HSCT by preventing the development of GVHD.

Unrelated Hematopoietic Stem Cell Transplantation for Children with Acute Leukemia: Experience at a Single Institution

We evaluate the outcomes in children with acute leukemia who received allogeneic hematopoietic stem cell transplantation (HCT) using unrelated donor. Fifty-six children in complete remission (CR) received HCT from unrelated donors between 2000 and 2007. Thirty-five had acute myeloid leukemia, and 21 had acute lymphoid leukemia. Stem cell sources included bone marrow in 38, peripheral blood in 4, and cord blood (CB) in 14. Four patients died before engraftment and 52 engrafted. Twenty patients developed grade II-IV acute graft-versus-host disease (GVHD) and 8 developed extensive chronic GVHD. With median follow-up of 39.1 months, event free survival and overall survival were 60.4% and 67.5%, respectively, at 5 yr. Events included relapse in 10 and treatment-related mortality (TRM) in 10. The causes of TRM included sepsis in 4, GVHD in 4 (1 acute GVHD and 3 chronic GVHD), veno-occlusive disease in 1 and fulminant hepatitis in 1. Patients transplanted with CB had event free survival of 57.1%, comparable to 63.2% for those transplanted with other than CB. In conclusion, HCT with unrelated donors is effective treatment modality for children with acute leukemia. In children with acute leukemia candidate for HCT but lack suitable sibling donor, unrelated HCT may be a possible treatment option at the adequate time of their disease.

Hematopoietic Stem Cell Transplantation with Using Multinational Unrelated Donors for Acute Myelogenous Leukemia / 대한혈액학회지

BACKGROUND: Many AML patients have received hematopoietic stem cell transplantation (HSCT) from HLA-matched unrelated donors. According to many of the previous reports, those patients could achieve long-term, disease-free survival after HSCT from multinational unrelated donors with tolerable transplant-related complications, even when there are HLA-mismatches. METHODS: We present the results of 35 unrelated hematopoietic stem cell transplantations from multiple international donor banks including the Korean (n=24), and Japan Marrow Donor Program (n=3), the Taiwan Tzu Chi Marrow Donation Registry (n=6), as well as using Caucasian donors from the National Marrow Donor Program (n=2), for the treatment of AML patients. RESULTS: The median age of patients was 36 (range: 16~53) and the median follow-up duration was 21 months (range: 5~60). Also, the median age of the donors was 28 (range: 20~53). The majority of the patients had intermediate or unfavorable cytogenetic features. The main conditioning regimen we used consisted of cyclophosphamide plus TBI (n=31) with our standard GvHD prophylaxis that contained tacrolimus plus a short course of methotrexate. Some patients (n=10) received an additional two-day course of ATG (thymoglobulin, Sangstat) in addition to the standard regimen. All the transplanted patients achieved engraftment. The incidence of acute GvHD was 42%, and that of chronic GvHD was 56%. Four (11%) patients have relapsed to date. The two-year non-relapse transplant-related mortality was 26%. The estimated probability of DFS and the event-free survival at five-years were 80% and 53%, respectively. CONCLUSION: These results suggest that multinational unrelated donors HSCT may provide a feasible option for the treatment of high-risk Korean AML patients.

Long-term Graft Outcome of Living Donor Renal Transplantation: Single Center Experience / 대한이식학회지

PURPOSE: The number of potential renal transplant recipients far exceeds the number of cadaveric donors. For this reason, living-related donors (LRD) and living-unrelated donors (LURD) have been used to decrease the cadaveric donor shortage. We analyzed 571 living donor transplants for 25 years in our center. METHODS: From 1978 to 2003, 571 patients underwent LRD (n=253) or LURD (n=318) kidney transplantation. The patients were divided into precyclosporin era (1978~1987, n=43, era I), cyclosporin era (1988~1997, n=368, era II), and cyclosporin plus mycophenolate- mofetil era (1998~2003, n=160, era III). We compared the graft survival rate of the recipients according to the immunosuppressants and analyzed the variables such as donor's and recipient's age, sex, HLA matching and acute rejection rate. We also compared the long-term survival rate between LRD and LURD. RESULTS: 1 and 10-year graft survival rates of all patients were 94.3% and 75.5%, respectively. 1 and 10-year graft survival rates were 74.4% and 36.2% in era I, 94.3 % and 78.4% in era II. 1 and 5-year graft survival rates were 96.7% and 90.5% in era III (P<0.001). The occurrence rate of acute rejection was 23.3% (era I), 22.3% (era II), and 14.3% (era III) (P=0.000). 1 and 10-year graft survival rates were 92.3% and 81.3% in LRD transplants, and 94.1% and 86.5% in LURD transplants, respectively (P =0.1909). CONCLUSION: The graft survival rates of living donor transplants are improving due to advances of patient care and new immunosuppressive agents. We suggest that living donors will be an important source of kidney transplantations.

A Successful Transplant of HLA-3 Loci Mismatched Umbilical Cord Blood into a Patient with Acute Myeloid Leukemia from an Unrelated Donor

Cord blood is a useful source of allogeneic hematopoietic stem cells for bone marrow reconstitution. The number of umbilical cord blood transplants is increasing worldwide. In this a case 15- month-old boy with acute myeloid leukemia was treated with umbilical cord blood transplant from an HLA-3 loci mismatched unrelated donor. Granulocyte recovery greater than 500/mm3 occurred at day 49, and the platelet recovered greater than 20,000/mm3 independent of transfusion at day 81 after stem cell infusion.

Analysis of the Process for Unrelated Stem Cell Donor Search / 대한혈액학회지

BACKGROUND: Between 1994 and 1999, 38,264 potential marrow donors typed for HLA- A, -B, and -DRB1 antigens had been recruited in the Korean registries. During the same period, 131 unrelated transplants have been carried out in Korea. In present study, the search procedure within the last two years for an unrelated donor at the Catholic University of Korea is analyzed. METHODS: The search for an unrelated donor for 287 patients was performed. Low resolutional HLA-A and -B typing was performed by serology and HLA-DRB1 typing was done by DNA-typing. We analyzed HLA match rate, the intervals between search activation and transplant, coordination success rate, and the reasons of coordination failure. We also investigated the RESULTS of donor search process through the Japan Marrow Donor Program (JMDP) and Tzu-Chi Taiwan Marrow Donor Registry (TCTMDR). RESULTS: At least one HLA-identical donor has been found for 54.7% of 287 patients in the first search using the Korean registries. As of the end of July 2000, 53 patients had received unrelated transplants and the coordination success rate was 33.8%. The average interval to transplant with the Korean registries was 128 days. The most common diagnosis in the patients who underwent transplantation was CML. Among 47 patients who registered in the JMDP, 25 patients found at least one HLA- identical donor. Twelve of them were transplanted. The average time to transplants was 149 days. Since February 2000, we have registered 22 patients in the TCTMDR. Four of them had one HLA-matched donor and transplants are now in progress. CONCLUSION: The donor pool is rapidly expanding and the patients who receive unrelated transplant are also increasing in Korea. From these data, we realized that the international collaboration of Asian countries would be very important for facilitating unrelated transplants for patients who could not find suitable donor in their national registries.