Optimizing conditioning regimen with low-dose irradiation or busulfan enables the outcome of transplantation from a 6-7/8 HLA-matched donor comparable to that from an 8/8 HLA-matched unrelated donor in severe aplastic anemia patients under 40 years.

With the dramatic improvements in outcomes following alternative donor hematopoietic stem cell transplantation (HSCT), interest in the use of alternative donors in severe aplastic anemia (SAA) is increasing. We conducted a multicenter prospective study to explore the efficiency and safety of upfront HSCT from a 6-8/8 HLA-matched unrelated donor (MUD) or 6-7/8 HLA-matched related donor (MRD) in acquired SAA patients under 40 years. Between August 2014 and July 2017, 115 patients were enrolled, including 48 (41.7%) patients receiving grafts from an 8/8 MUD, 25 (21.7%) from a 6-7/8 MRD, and 42 (36.5%) from a 6-7/8 MUD. The incidence of grade II-IV acute graft-versus-host disease (GVHD) was higher in the 6-7/8 MUD group than in the 8/8 MUD group (42.9% vs. 12.8%, P=0.001). The corresponding incidence in the 6-7/8 MRD group was comparable to that in the 8/8 MUD group (21.7% vs. 12.8%, P=0.332). There was no significant difference in the incidence of chronic GVHD (24.3%, 13.6%, and 17.9%, P=0.676), graft failure (2.4%, 8.0%, and 6.3%, P=0.551), overall survival (85.7%, 96.0%, and 87.5%, P=0.424), and failure-free survival (83.3%, 88.0%, and 83.3%, P=0.885) among the three groups (6-7/8 MUD, 6-7/8 MRD, and 8/8 MUD). In multivariate analysis, conditioning regimen without low-dose irradiation or busulfan was associated with an inferior failure-free survival (HR=2.973, P=0.042). In conclusion, after an intensified conditioning regimen with additional low-dose irradiation or busulfan, the outcome of HSCT from a 6-7/8 MRD or 6-7/8 MUD is comparable to that from an 8/8 MUD.

Prognosis of haploidentical hematopoietic stem cell transplantation in non-infant children with t(v;11q23)/MLL-rearranged B-cell acute lymphoblastic leukemia.

B-cell acute lymphoblastic leukemia (B-ALL) with MLL-rearrangements (MLL-r) is rare in pediatric patients (aged >1 year), and optimal treatment strategies remain unclear. This study aimed to retrospectively evaluate the clinical characteristics, outcomes, and effects of allogeneic hematopoietic stem cell transplantation (allo-HSCT) of 37 non-infant children with t(v;11q23)/MLL-r B-ALL. Their 4-year overall survival (OS), event-free survival (EFS), and cumulative incidence of relapse (CIR) were 69.8 %, 58.2 %, and 39.1 %, respectively, and differed significantly between patients receiving allo-HSCT (18/19 cases received haploidentical [haplo]-HSCT) at the first complete remission (HSCT at CR1, n = 19; 87.4 %, 89.5 % and 5.3 %) and those continuing consolidation therapy (Non-HSCT at CR1, n = 18; 52.2 %, 25.9 %, and 74.1 %, respectively), and the p values were 0.022, <0.001 and <0.001, respectively. Of the 13 patients experiencing relapse during consolidation chemotherapy, the five continuing with chemotherapy only died within 44 months, and the eight patients opting for allo-HSCT after CR2 had a 4-year OS of 57.1 %. Multivariate analysis revealed HSCT at CR1 as the only independent protective factor for OS, EFS, and CIR. The present results indicate that allo-HSCT (especially haplo-HSCT) at CR1 may decrease the relapse rate and improve the prognosis of non-infant children with t(v;11q23)/MLL-r B-ALL.

[A clinical study of haploid hematopoietic stem cells combined with third-party umbilical cord blood transplantation in the treatment of chronic granulomatous disease].

OBJECTIVE: To investigate the clinical efficacy of haploid hematopoietic stem cells (haplo-HSC) combined with third-party umbilical cord blood (tpCB) transplantation in the treatment of X-linked chronic granulomatous disease (X-CGD). METHODS: The clinical data of 26 boys with X-CGD were retrospectively analyzed who were admitted to the Sixth Medical Center of PLA General Hospital between April 2014 and March 2018. All the patients were treated with haplo-HSC combined with tpCB transplantation. The median age of the patients was 3.5 years. The donor was the father in 25 cases and an aunt in 1 case. Transplantation was 5/6 HLA-matched in 9 cases, 4/6 in 12 cases, and 3/6 in 5 cases. The patients received busulfan, cyclophosphamide, fludarabine, or anti-thymocyte globulin for myeloablative preconditioning. Cyclosporine A and mycophenolate mofetil were used for prevention of acute graft-versus-host disease (aGVHD). Then the patients were treated with haploid bone marrow hematopoietic stem cells combined with tpCB transplantation on day 1 and haploid peripheral hematopoietic stem cells on day 2. The counts of median donor total nucleated cells, CD34+ cells, and CD3+ cells were 14.6×108/kg, 5.86×106/kg, and 2.13×108/kg respectively. RESULTS: The median time to neutrophil and platelet engraftment was 12 and 23 days after transplantation respectively. Full donor hematopoietic chimerism was observed on day 30. Twenty-five cases were from haplo-HSC and 1 was from cord blood. No primary implant failure and implant dysfunction occurred, and secondary implant failure occurred in one case. The NADPH oxidase activity returned to normal one month after transplantation. The incidence of grade I-II aGVHD and grade III-IV aGVHD was 35% and 15% respectively. Chronic GVHD (cGVHD) of the skin occurred in one case, and no progression was observed after steroid administration. During the follow-up period of 6-51 months, 25 patients survived, of whom 24 were disease-free (23 patients without cGVHD and 1 with cGVHD of the skin) and NADPH oxidase activity returned to normal; one patient developed secondary implant failure but survived; one patient died of viral interstitial pneumonia 16 months after transplantation. The 5-year event-free survival rate and overall survival rate were 81%±12% and 89%±10% respectively. CONCLUSIONS: Haplo-HSC combined with tpCB transplantation is one of the effective methods for the treatment of X-CGD in children.

Unmanipulated haploidentical haematopoietic stem cell transplantation for children with severe aplastic anaemia.

Haploidentical haematopoietic stem cell transplantation (haplo-HSCT) used to be a third-line treatment option for childhood severe aplastic anaemia (SAA). We conducted this retrospective study of 36 children (38 transplants) who received haplo-HSCT from human leucocyte antigen (HLA)-mismatched related donors between July 2002 and November 2013 at five HSCT centres in China, including 17 cases that were 5/6 HLA matched (Group 1) and 21 that were 4/6 or 3/6 HLA matched (Group 2). Although patients in Group 2 had a higher incidence of grade II-IV acute graft-versus-host disease (57·9% vs. 5·9%, P = 0·001), they had similar rates of graft failure (5·3% vs. 5·9%, P = 0·742) and overall survival (80·8% vs. 93·8%, P = 0·234) as Group 1. Unmanipulated haplo-HSCT is an effective treatment for SAA children with satisfactory outcome of this cohort, especially in the 5/6 HLA-matched group. For patients in critical situations, such as unresponsive to immunosuppressive therapy, refractory infection and failing first HSCT, to bring forward the timing of haplo-HSCT is a feasible salvage strategy with better and faster donor accessibility.

[Clinical effect of umbilical cord blood transplantation in 37 pediatric patients with hematologic malignancies: a single-center experience].

OBJECTIVE: To evaluate the clinical effect of umbilical cord blood transplantation (UCBT) in children with hematologic malignancies. METHODS: A retrospective analysis was performed on the clinical data of 37 pediatric patients with hematologic malignancies that consisted of 14 cases of acute lymphocyte leukemia, 9 cases of acute myeloid leukemia, 5 cases of juvenile myelomonocytic leukemia, 3 cases of chronic myeloid leukemia, 2 cases of acute mixed leukemia, 3 cases of myelodysplastic syndrome, and 1 case of lymphosarcomatous leukemia. Thirty-seven children with hematologic malignancies received UCBT from unrelated donors (34 cases) and related donors (3 cases). Grafts were 6/6 HLA-matched in 5 cases, 5/6 HLA-matched in 12 cases, 4/6 HLA-matched in 11 cases, and 3/6 HLA-matched in 9 cases. Before transplantation, these patients received rabbit antithymocyte globulin-containing conditioning regimen. The myeloablative conditioning regimen was given in 36 cases and the reduced-intensity conditioning regimen in one case. The median age of transplantation was 5.7 years, and the median weight was 20 kg. The grafts that contained a median of 6.2×10(7) total nucleated cells (TNC)/kg and 2.7×10(5) CD34(+) cells/kg were infused. RESULTS: The median times to neutrophil engraftment and platelet engraftment were 12 days and 25 days, respectively, and the rates of neutrophil engraftment and platelet engraftment were 95% and 78%, respectively. The rate of neutrophil engraftment was positively correlated with the number of CD34(+) cells (P=0.011), while the rate of platelet engraftment was correlated with the numbers of CD34(+) cells and TNC (P=0.001; P=0.014). The incidence rates of acute and chronic graft-versus-host disease were 49% and 11%, respectively. The median follow-up was 54 months. The 5-year transplant-related mortality, overall survival, and disease-free survival were 27%, 57.4% and 41%, respectively. CONCLUSIONS: UCBT is an alternative source of hematopoietic stem cells for patients with hematologic malignancies.

[Morphologic diagnosis and onset characteristics of acute leukemia: a retrospective analysis of 233 cases in 10 years].

The objective of this study was to evaluate the value of morphologic diagnosis for acute leukemia (AL), to explore the relation of morphologic diagnosis with immunology, cytogenetics and molecular biology diagnosis of AL and to analyze the onset characteristics of AL in 10 years. The samples of bone marrow and peripheral blood from 233 newly diagnosed cases of AL were collected during 2001-2011 years; the morphologic examination and immunologic, cytogenetic and molecular biologic examination (ICM) were carried out, the consistency of morphologic diagnosis with ICM diagnosis was compared, the onset characteristics of AL was analyzed. The results showed that: (1) the consistent rate of immunology, cytogenetics, molecular biology diagnosis with morphologic diagnosis was 84.3%. The order of consistent rat was AUL, M0 < M1 < HAL < M4 < M2 < M3 < M5 < ALL < M6, M7, AP; (2) Misdiagnosis always occurred among AUL, M0, M1, ALL and HAL or among M2a, M3v, M4 and M5. (3) In 233 cases, the highest ratio of blast was observed in M1 (92.5%), while the lowest ratio of blast was observed in M2 (49.5%). (4) AL occurred more frequently in males than that in female (147:86). (5) AL occurred in patients aged from 1 to 88 years. The median age was 41.5 for AUL, 40.8 for M0, 43.4 for M1, 46.3 for M2, 33.8 for M3, 42.6 for M4, 48.8 for M5, 77.3 for M6, 2.5 for M7, 65.0 for AP, 29.1 for ALL and 40.3 for HAL. (6) The number of patients in the later five years (139 cases) was significantly greater than that in the first five years (94 cases), especially the patients with M1, M2, M3, M4, and M5. It is concluded that morphologic diagnosis has important clinical value in the MICM diagnosis of AL. Attaching importance to the confusing cell morphology and onset characteristics of AL can improve the diagnostic accuracy.

[Comparison of total body irradiation-cyclophosphamide versus busulphan-cyclophosphamide as conditioning regimens for myelogenous leukemia: a meta-analysis].

Total body irradiation combined with cyclophosphamide (TBI/CY) and busulphan combined with cyclophosphamide (BU/CY) are standard conditioning regimens in hematological stem cell transplantation for patients with myelogenous leukemia. This study was aimed to compare the therapeutic efficacy of TBI/CY and BU/CY as conditioning regiment for acute or chronic myelogenous leukemia. The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, CNKI, CBM (Chinese Bio-medicine Database) had been searched for all relevant articles (1999-2007). Comparative studies were carried out on clinical therapeutic effects of TBI/CY and BU/CY including stem cell engraftment, relapse, complications, transplant-related mortality, and disease-free survival. A meta-analysis was performed using Review Manager 4.2 software and funnel plot regression was adopted to assess the publication bias. The results indicated that 2149 articles in English and 46 articles in Chinese were got, and finally 9 clinical trials with total 3039 patients have been assessed. No significantly difference was found in engraftment failure and transplant-related mortality resulting from TBI/CY and BU/CY conditioning regimens, but the incidence of veno-occlusion of liver and hemorrhagic cystitis obviously increased in BU/CY group after transplantation, the acute GVHD, interstitial pneumonia and cataract significantly increased in TBI/CY group. The relapse rate of AML in TBI/CY group was lower than that in BU/CY group, and the rate of long-term disease-free survival of AML patients in TBI/CY group also significantly lower than that in BU/CY group, but the relapse rate of CML in TBI/CY group after transplantation was obviously higher than that in BU/CY group, but there was no difference in longterm disease-free survival rate between the two conditioning regimens mentioned above. It is concluded that the meta-analysis confirms different effects of TBI/CY and BU/CY regimens on myelogenous leukemia transplantation. This result is useful for physicians to select treatment regimens.

[Unrelated umbilical cord blood transplantation as a treatment for children with malignant leukemia].

OBJECTIVE: Unrelated umbilical cord blood has the clear benefits of rapid availability and a reduced stringency of requirement for HLA match. The aim of this study was to investigate the efficacy of unrelated umbilical cord blood transplantation (UCBT) in the treatment of malignant leukemia in children. METHODS: Six children with malignant leukemia, including three cases of acute lymphocyte leukemia [two high-risk patients and one standard-risk patient in complete remission (CR)], two juvenile myelomonocytic leukemia (one in CR and one in the accelerating stage), and one acute myeloblastic leukaemia (in CR), received a UCBT. The umbilical cord blood grafts were HLA-matched (n=1) or HLA-mismatched at 1 (n=1) or 2 (n=1) or 3 (n=3) loci. Busulfan/cyclophosphamide/antithymocyte globulin (ATG) or total body irradiation (TBI)/cyclophosphamide/ATG was involved in the myeloablative pretreatment regimen. The median infused donor nucleated cell was 8.51 x 10(7)/kg of recipient weight, and the CD34+ cell was 1.81 x 10(5)/kg of recipient weight. Cyclosporin, corticoid, mycophenolate mofetil and daclizumab were used for prophylaxis of acute graft versus host disease (GVHD). RESULTS: The time to reach an absolute neutrophil count of 0.5 x 10(9)/L ranged from 11 to 35 days (median: 13 days) and the time to reach a platelet count of 20 x 10(9)/L ranged from 27 to 68 days (median: 30 days) after transplantation, and the donors' hematopoietic stem cells were shown in these patients. Four patients developed grade I to III acute GVHD but responded to steroids and daclizumab. Chronic GVHD was not found during a 3-16-month follow-up. Four patients survived and did not relapse during the follow-up. CONCLUSIONS: Unrelated umbilical cord blood is an alternative source of hematopoietic stem cells for patients with leukemia. UCBT can tolerate 1-2 HLA mismatches. The incidence of acute GVHD is high in UCBT recipients.

[Comparison of different cryopreservation systems for peripheral blood stem cells].

AIM: To explore proper cryopreservative systems for hematopoietic stem cells. METHODS: Peripheral blood mononuclear cells from 20 persons were mixed with different cryopreservative agent, dimethyl suflfoxide (DMSO) or combination of DMSO and hydroxyethyl starch (HES), then cooled in -80 degrees C low temperature refrigerator (Refr) or autocontrolled programmed cryogenic system (PCS), preserved in Refr or in liquid nitrogen. GM-CFU, LTC-IC, CD34+ cells and typeran blue resistance (TBR) were assayed after different period of cryopreservation. RESULTS: The recovery rates of CFU-GM, LTC-IC, CD34+ cells and TBR in peripheral blood mononuclear cells which were cooled and preserved in Refr with 5% DMSO-6% HES were 82.2% +/- 14.7%, 83.0% +/- 12.2%, 94.2% +/- 4.3% and 97.7% +/- 3.9% respectively, significantly higher than that in Refr with 10% DMSO (P < 0.05). When cells were cryopreservated with the same cryopreservatives, there was no significantly difference of recovery rate in group of Refr and group of Refr with PCS. Meanwhile, there was not significantly difference of recovery rate among all three groups, preserved in Refr ahead of liquid nitrogen, in Refr merely, in liquid nitrogen with PCS within one year (p > 0.05). However, the recovery rate of CFU-GM, LTC- IC, CD34+ cells and TBR decreased dramatically if cells were cooled and preserved in Refr for two years. After cells were thawed, the cell activity declined gradually at room temperature if the cryopreservatives were not removed or diluted. The cell activity of 10% DMSO group was affected more than that of 5% DMSO-6% HES group. CONCLUSION: 5% DMSO-6% HES is better than 10% DMSO as cryopreservatives for hematopoietic stem cells. Refr cryopreservation is a simple and effective method if cells would be cryopreserved for less than one year. If cells would be cryopreserved for more than one year, liquid nitrogen cryopreservation should be recommended. The cryopreservatives should be diluted or removed immediately after cells were thawed.

[Treatment of refractory rheumatism among preschool children with autologous peripheral blood hematopoietic stem cell transplantation].

OBJECTIVE: To investigate the feasibility and safety of autologous peripheral blood hematopoietic stem cell transplantation (auto-PBHSCT) and its therapeutic effect on refractory rheumatism among preschool children. METHODS: Three boys with juvenile rheumatoid arthritis (JRA), juvenile systemic lupus erythematosus (JSLE) and juvenile dermatomyositis (JDM) respectively, 3 to 6 years old with the mean age of 5 years with 3.5 to 22 months course of disease with 14 months on average, received auto-PBHSCT. Their conditions were so severe that conventional therapy failed to control the diseases. The changes of both clinical manifestations and immunologic indexes were observed before and after transplantation with long term following up at specialty clinic of rheumatism. RESULT: The time when neutrophil count >or= 0.5 x 10(9)/L in the 3 children was days +9, +13 and +11 respectively, that of platelet count >or= 20 x 10(9)/L was days +14, +18 and +13 respectively. The cellular immune function remained abnormal with CD4 cells at a low level and CD4/CD8 being inverted. As to the JDM child, the skin rash had disappeared and his muscle tone was improved to grade 5 within one month after the transplantation. The EMG and serum creatase level returned to normal and muscle MRI findings were improved greatly within 2 months after the transplantation. As to the JSLE child, skin rash and proteinuria had disappeared, MRI of brain showed that the pathological changes had been absorbed and EEG returned to normal 3 months after the transplantation, all the autoantibodies turned to negative within 8 months after transplantation. As to the JRA child, the arthritis had been improved remarkably within 3 weeks after auto-PBHSCT. There was no swelling of joints nor movement limitation 3 months post transplantation. The steroids and immunosuppressive drugs were discontinued post transplantation. Cushing syndrome disappeared. Their body heights increased by 10 to 15 cm in the past 18 months, and they all returned to school. There was no relapse during follow-up periods of 25 - 27 months. CONCLUSION: The therapy with auto-PBHSCT for refractory rheumatism among preschool children was remarkably effective in a short-term, yet the safety and long-term effect still need to be further studied.

Mixed hematopoietic chimerism for preventing graft-versus-host disease in mice receiving rat bone marrow transplantation.

OBJECTIVE: To find a method for preventing graft-versus-host disease (GVHD) in BALB/c mice receiving rat bone marrow transplantation. METHODS: Firstly 12 SD rats were conditioned with 5.0 Gy sublethal total body irradiation(TBI), followed by infusion of 8 x 10(7) bone marrow cells from 28 BALB/c mice within 4 h and intraperitoneal administration of 100 mg/kg cyclophosphamide (Cy) 2 d later, for the purpose of inducing chimeric SD rats with specific immunological tolerance. Secondly, 24 BALB/c mice were exposed to 9.0 Gy lethal TBI and divided randomly into 3 equal groups designated respectively as groups A, B and C. Mice in group A were injected with 4 x 10(7) bone marrow cells from 4 normal rats, and mice in group B were injected with 4 x 10(7) bone marrow cells and 2 x 10(7) spleen cells from 4 normal rats, while those in group C were given 4 x 10(7) bone marrow cells and 2 x 10(7) spleen cells from 6 chimeric rats. The mice were then observed for 150 d for GVHD. RESULTS: In the second procedure, 2 mice in group A failed to survive due to infection and radiation injury respectively, and none of the rest mice presented signs of GVHD. The mice in group B all developed GVHD of varied degrees with symptoms as wasting, diarrhea, fur loss, arched body posture, and even bloody stool, and all died within 5 to 15 d with an average survival of 10.0 d (95% confidence interval 8,12). Pathological examination of the liver and intestinal tissues revealed inflammatory lymphocyte infiltration and necrosis. The majority of the mice in group C, in contrast, survived for more than 150 d with only two died on the postoperative days 18 and 31 respectively. The survival time of group B was significantly shorter than that of the other two groups. CONCLUSION: Donor/recipient chimerism may help prevent GVHD in xenogeneic bone marrow transplantation.