Efficacy and Prognostic Factors of Nonmyeloablative Allogeneic Hematopoietic Stem Cell Transplantation for Patients with Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To retrospectively analyze the efficacy and complications of our institution's modified nonmyeloablative allogeneic hematopoietic stem cell transplantation (NST) in treating intermediate-risk acute myeloid leukemia (AML) - first complete remission (CR1) and prognostic factors.@*METHODS@#Clinical data of 50 intermediate-risk AML-CR1 patients who underwent matched related NST at the Fifth Medical Center of Chinese People's Liberation Army General Hospital from August 2004 to April 2021 were collected, the hematopoietic recovery, donor engraftment and complications were observed, and overall survival (OS) rate, leukemia-free survival (LFS) rate, treatment-related mortality (TRM), and cumulative relapse rate were calculated. Statistical analysis of factors affecting prognosis was also preformed.@*RESULTS@#The median times for neutrophil and platelet recovery after transplantation were 10 (6-16) and 13 (6-33) days, respectively. One month after transplantation, 22 patients (44%) achieved full donor chimerism (FDC), and 22 patients (44%) achieved mixed chimerism (MC), among whom 18 cases gradually transited to FDC during 1-11 months, 4 cases maintained MC status. The overall incidence of acute graft-versus-host disease (aGVHD) was 36%, with a rate of 18% for grade II-IV aGVHD and a median onset time of 45 (20-70) days after transplantation. The overall incidence of chronic GVHD (cGVHD) was 34%, with 20% and 14% of patients having limited or extensive cGVHD, respectively. The incidence rates of infections, interstitial pneumonia, and hemorrhagic cystitis were 30%, 10%, and 16%, respectively. The 5-year OS rate, LFS rate, TRM, and cumulative relapse rate were 68%, 64%, 16%, and 20%, respectively. The increase of the number of CD34+ cells infused had shortened the recovery time for neutrophils and platelets (r =0.563, r =0.350). The number of CD34+ cells infused significantly influenced the occurrence of extensive cGVHD (OR =1.36, 95%CI : 1.06-1.84, P =0.024).@*CONCLUSION@#Modified NST is effective in treating intermediate-risk AML-CR1 patients, however, further expansion of sample size is needed to study prognostic factors.

Biological characteristics of Microvesicles Derived from Bone Marrow Mesenchymal Stem Cells and Their Capacities Supporting ex vivo Expansion of Hematopoietic Stem Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the biological characteristics of microvesicles(MV) derived from bone marrow mesenchymal stem cells (BM-MSC) and their capability supporting ex vivo expansion of hematopoietic stem cells(HSC).</p><p><b>METHODS</b>The MV from cultured BM-MSC supernatant were isolated by multi-step differential velocity contrifugation; the morphological characteristics of MV were observed by electron microscopy with negative staining of samples; the protein level in MV was detected by using Micro-BCA method; the surface markers on MV were analyzed by flow cytometry. The peripheral blood HSC(PB-HSC) were isolated after culture and mobilization; the experiment was diveded into 2 group: in MV group, the 10 mg/L MV was given, while in control group, the same volume of PBS was given; the change of PB-HSC count was observed by cell counting; the change of surface markers on PB-HSC was detected dynamically by flow cytometry; the cell colony culture was used to determin the function change of PB-HSC after co-culture with MV.</p><p><b>RESULTS</b>MSC-MVs are 20-100 nm circular vesicles under electron microscope. About 10 µg protein could be extracted from every 1×10MSC. The flow cytometry showed that CD63 and CD44 were positive with a rate of 96.0% and 50.2%, while the HLA-DR, CD34, CD29 and CD73 etc were negative. When being co-cultured with GPBMNC for 2 days, the cell number of MV groups was 1.49±0.15 times of the control group (P>0.05). When being co-cultured for 4 days, the cell number of MV groups was 2.20±0.24 times of the control group(P<0.05). The CD34cell number of MV groups was 1.76±0.30 times the control group after culture for 2 day and 1.95±0.20 times after culture for 4 day.</p><p><b>CONCLUSION</b>The MV has been successfully extracted from MSC culture supernatant by multi-step differential velocity centrifugation. MSC-MV can promote HSC expansion in vitro.</p>

Effect of Infusion of Recipient Spleen Cells at Different Time after Murine Haploidentical Hematopoietic Stem Cell Transplantation on Graft Versus Host Disease / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the effect of infusing G-CSF mobilized recipient spleen cells at different time after haploidentical stem cell transplantation(HSCT) on graft-versus-host disease (GVHD) in mice and its possible mechanism.</p><p><b>METHODS</b>Forty mice after HSCT were randomly divided into 4 groups (n=10): GVHD positive control group (control group), 1st d recipient cell infusion group after transplantation (+1 d group), 4th d recipient cell infusion group after transplantation(+4 d group), 7th d recipient cell infusion group after transplantation(+7 d group). The mice in control group were injected the normal saline of same equivalent with experimental group which were given the same amount of G-CSF-mobilized recipient spleen cells. The general manifestation and pathological change of GVHD were observed. The expression changes of CD3CD4, CD3CD8cell subsets and FasL in peripheral blood were detected by flow cytometry.</p><p><b>RESULTS</b>The incidence of GVHD was significantly decreased in +4 d group and the median survival time was longer than 60 days, which was significantly higher than that of control group (24 d), +1 d group (21 d), +7 d group (28 d). (P<0.01, P<0.01, P<0.01). The Fasl expression of peripheral blood T lymphocytes in +4 d group were significantly lower than that in the other 3 groups(P<0.05).</p><p><b>CONCLUSION</b>The +4 d infusion of G-CSF mobilized recipient spleen cells on 4th day after haploidentical HSC transplantation can inhibit the expression of FasL in donor T lymphocytes, and significantly reduce the incidence of GVHD.</p>

Biological Characteristics of Microvesicles Secreted by Human Peripheral Blood Hematopoietic Stem Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of microvesicles(MV) isolated from human peripheral blood hematopoietic stem cells(PB-HSC) on immune regulation and hematopoiesis.</p><p><b>METHODS</b>PB-HSCs were separated by density-gradient centrifugation and cultrued. The supernatants of PB-HSC at 48 h were harvested for isolation and purification of MV by using ultracentrifugation. The electron microscopy was used to observe the morphology of MV. The protein level in MV was quantified through bicinchoninic acid(BCA) protein assay. Flow cytometry was used to detect the immunophenotype of MV. Human peripheral blood mononuclear cells(PB-MNC) were isolated from healthy donor and treated with isolated MV. After being co-cultured for 12 h, confocal microscopy was used to observe the action mode of MV on PB-MNC. After being co-cultured for 48 h, the levels of IL-2, IL-6, IL-8, IL-10, IFN-γ and TNF-α were detected by ELISA. Flow cytometry was used to detect the changes of T cell subsets and the activation of T cell subsets as well as intracellular cytokine staining after co-culture for 48 h. The methylcellulose was used to assess the hematopoiesis-supportive function of MV as well as co-cultured supernatants.</p><p><b>RESULTS</b>The eletron microscopy revealed that MV were elliptical membrane vesicles. The protein amount in MV ranges from 29 to 110 µg. Flow cytometry showed that MV expressed mix markers on the surface, especially highly expressed MV specific marker CD63(85.86%) and hematopoietic stem cell marker CD34(33.52%). After being co-cultured for 12 h, confocal microscopy showed that MV were merged with PB-MNC. After being co-cultured for 48 h, ELISA showed that the secretion of cytokines IL-6,IL-8, IL-10 as well as TNF-α was increased while the level of IL-2 and IFN-γ was not changed much. The results of flow cytometry showed that there was no significant change in T cell subsets and T cell activation. Staining of intracellular factor showed that IL-8 was increased significantly in CD11ccells. The colony-forming experiments revealed that MV and the co-cultured supernatants could facilitate the colony formation.</p><p><b>CONCLUSION</b>MV isolated from PB-HSC have immune-regulatery function and can prornote hematopoiesis.</p>

Establishment of Mouse Model of H-2 Haploidentical Hematopoietic Stem Cell Transplantation from Double Donors / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To establish a new mouse model of H-2 haploidentical stem cell transplantation from double donors (DHSCT) and compare with conventional haploidentical hematopoietic stem cell transplantation (HSCT) so as to alleviate transplant-related complications.</p><p><b>METHODS</b>The recipients CB6F1 of conventional HSCT group were pretreated by 8 Gy total body irradiation(TBI), and received 3×10donor (male C57) spleen mononuclear cells (spMNC) mobilized by G-CSF within 2 hours after TBI. Recipients CB6F1 of D-HSCT groups accepted 2 Gy TBI, and received total 12×10spMNC mobilized by G-CSF from 2 donors within 2 hours after TBI, each donor donated 6×10cells. According to the different strains and sex of donors, DHSCT were divided into 3 groups: in group A, the stem cells were from male C57 and female BALB/c; in group B, stem cells were from male C57 and male BALB/c, while the stem cells in group C were from male C57 and male C3H. Hematopoietic reconstruction, engraftment, GVHD and survival were observed among these 4 groups.</p><p><b>RESULTS</b>The nadir of white blood cell count after conventional HSCT were lower than 1×10/L and lasted for 3 to 5 days, while not less than 3×10/L after D-HSCT among either group A, B or C. The complete chimerism (CC) in conventional HSCT group was achieved quickly within only 1 week in peripheral blood. Mixed chimerism (MC) in peripheral blood was found within the first week after DHSCT among either group A, B or C, and transformed into stable CC within the second week eventually. Both GVHD morbidity and mortality of conventional HSCT were 100% at 34th day after transplantation.Among DHSCT groups,the overall GVHD morbidity and mortality at 34th day after transplant were 49.6% and 50%(P<0.01,P<0.05), respectively,and 60.4% and 81.2% at 50th day after transplant. Overall survival of 50 days was 50.9% that indicated a long survival in such mice DHSCT. The differences of hematopoietic reconstruction, donor cell engraftment, GVHD incidence, GVHD mortality and OS were not statistically significant among group A, B and C(P>0.05).</p><p><b>CONCLUSION</b>A new mouse model of H-2 haploidentical peripheral blood stem cell transplantation from double donors (DHSCT) has been successfully established by reducing conditioning intensity and increasing graft cell numbers from double haploidentical donors without GVHD prophylaxis. DHSCT successfully achieved stable complete chimerism, less GVHD morbidity and mortality and longer OS without hematopoietic suppression. This study provides experimental evidence for clinical application of HLA haploidentical peripheral blood stem cell transplantation from double donors.</p>

Expression of WT1 Gene in Bone Marrow of Patients with Acute Myeloid Leukemia and Its Influence on Prognosis / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the expression level of WT1 gene in bone marrow of patients with acute myeloid leukemia (AML) and its relationship with prognosis.</p><p><b>METHODS</b>The copy numbers of WT1 and internal reference gene in bone marrow samples from 75 newly diagnosed AML patients were detected by using real-time quantitative PCR. The gene WT1 expression level was determined by the ratio of the copy numbers of WT1 to reference gene. And the clinical characteristics, the complete remission (CR) rate after induction chemotherapy, 2-year overall survival (OS) rate and event-free survival (EFS) rate were calculated and analysed.</p><p><b>RESULTS</b>The expression level of WT1 did not significantly correlate with common clinical parameters such as age, sex, molecular abnormality, FAB classification and risk stratification. The CR rate in the high WT1 expression group before treatment was 65.4%, which was lower than that of 93.9% in the low expression group (χ2=8.25, P<0.01). The 2-year overall survival rate and event-free survival rate of the two groups were statistically significantly different (P<0.05), and the OS and EFS rates in high WT1 expression group were lower than those in low expression group. After the induction chamotheropy for about 1, 3 month and 6 months, the 2-year OS rate significantly increased in patients with decrease of WT1 gene expression level by one log or more (P<0.05).</p><p><b>CONCLUSION</b>The expression level of WT1 gene in bone marrow may be an effective marker to evaluate therapy efficacy and prognosis for AML patients (non APL).</p>

A case report of refractory pleural effusion associated with dasatinib in the treatment of chronic myeloied leukemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To study the clinical features and prognosis of pleural effusion associated with dasatinib in treatment of chronic myeloid leukemia(CML).</p><p><b>METHODS</b>A 49 year old mal patient with CML who suffered pleural effusion(grade 3) associated with dasatinib was analyzed and summarized.</p><p><b>RESULTS</b>the patient achieved complete molecular response(CMR) after treating with dasatinib 100 mg once daily for 3 months. However, the symptom of chest distress occured in the patient after dasatinib treatment for 6 months, the chest CT scan showed bilateral pleural effusion(grade 3), the pleural effusion related with dasatinib was diagnosed, therefore the diuretic and steriod drugs were given, thoracocentesis was also used to relieve the symptom, after treatment for 5 weeks the pleural effusion disappeared, but the pleural effusion recurred when the patient taken dasatinib again, thus the dasatimib was permanently discontinued, but the patient was in CMR. Six months later, the patient began to take Imatinib (first TKI) 300 mg/d, good effects were achieved and no serious adverse effects were observed. Up to now, the patient still is in CMR for 20 months.</p><p><b>CONCLUSION</b>In the treatment of CML, appropriate TKI should be chose according to basic disease, and pleural effusion is one of the most common adverse effects during the therapy with dasatinib, close monitoring and timely intervention are necessary. For these patients who were intolerable to recieve the dasatinib, the conversion to another TKI may acquire satisfactory curative effect with tolerance of patients.</p>

Clinical efficacy of switching to 2nd generation of tyrosine kinase inhibitor on CML patients at poor responses to imatinib / 中国实验血液学杂志

<p><b>OBJECTIVE</b>This study was to investigate the timing and clinical efficacy of switching to the 2nd generation of tyrosine kinase inhibitor (TKI) for CML patients at poor response to imatinib (dissatifed efficacy or intolerance).</p><p><b>METHODS</b>The therapeatic efficacy and side reaction of switched 2nd TKI in patients with newly diagnsed CML-CP who poorly responded to imatinib were observed, anong them 3 cases were intolerant, 6 cases did not acquire satisfied efficacy.</p><p><b>RESULTS</b>After switching to 2nd generation TKI, 3 patients with intolerance achieved complete cytogenetic remission (CCyR) in 3 months, and major molecular remission (MMR) in 3-6 months. All of them achieved optimal efficacy according to European Leukemia Network (ELN), but the pleural effusion appeared in 1 case after use of 2nd generation of TKI for 3 months, and the dadatinib was stoped temporally, and the curative efficacy still was maintained. Among 6 cases with poor efficacy by treatment with imatinib, 2 cases with BCR/ABL mutation progressed after switching 2nd generation of TKI, out of them 1 case with poor tolerance progeressed to the accelerated phase, but was cured by haploidentical allogeneic hematopoictic stem cell transplantation, 1 case progressed to blastic crisis and died of serious infection; the another 4 cases achieved MMR in 3-12 months after using 2nd generation of TKI, and maintained CMR for 12-36 months.</p><p><b>CONCLUSION</b>CML-CP patients without the optimal response to imatinib should be treated by switching to 2nd generation of TKI as soon as possible, and thereby patients may acquired satisfactory therapentic efficacy.</p>

Efficacy of Nonmyeloablative Allogeneic Hematopoietic Stem Cells for 14 Case of Severe Acquired Aplastic Anemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the therapeutic efficacy of nonmyeloablative allogeneic hematopoietic stem cells transplantation for severe acquired aplastic anemia (SAA).</p><p><b>METHODS</b>Fourteen patients with severe acquired aplastic anemia received nonmyeloablative allogeneic hematopoietic stem cells transplantation from HLA matched sibling donors, among them 8 cases were dagnosed as SAA-I, 6 cases were diagnosed as SAA-II. The conditioning regimen consisted of fludarabine (FIUD), cyclophosphamide (CTX) and anti-thymocyte globulin (ATG/ALG). The prophylaxis for graft-versus-host disease (GVHD) was performed with cyclosporine (CsA) combined with mycophenolate mofetil (MMF) or tacrolimus (FK506).</p><p><b>RESULTS</b>All the patients gained a quick successfully engraftment of donor hametopoietic cells. The mean recovery time for neutrophil and platelet was 9 d and 13 d respectively. All the patients have acquired a full donor chimerism before 14 d. There were only 2 cases of GVHD: one out of them was acute skin GVHD (grade I) at day 70 after transplantation and the other was chronic liver GVHD (grade I) in 1 years after transplantation, the GVHD more than degree II did not coccur in all patients, 9 patients with bacterial and fungal mixed infection and (or) virus infection were observed, and improved after anti-infection therapy. The median follow-up time were 54.5 months (ranged between 5-144 months), and 12 patients remain disease-free survival currently, only 2 patients died of fungal infectin.</p><p><b>CONCLUSION</b>Transplantation of nonmyeloablative allogeneic hematopoietic stem cell is safe and effective for the treatment of severe acquired aplastic, but the prevention, treatment and monitoring of infection need to be enhance.</p>

Risk factors analysis of cytomegalovirus infection after nonmyeloablative allogeneic peripheral blood stem cell transplantation / 中国实验血液学杂志

The aim of this study was to analyze the risk factors of cytomegalovirus (CMV) infection and CMV disease after nonmyeloablative allogeneic hematopoietic stem cell transplantation(NST) and develop a rational strategy for the diagnosis, monitoring and preemptive treatment of CMV infection. The Clinical data of 80 patients undergoing NST from November 2009 to November 2012 in the hospital 307 were retrospectively analyzed. The cytomegalovirus load in peripheral blood of patients was detected by using RT-PCR. The results indicated that the incidence of CMV infection was 77.5% (62/80), and the median time for the positive CMV-DNA firstly detected by RT-PCR was day 35 (17-133) after NST. The total of 100-day cumulative incidence of CMV disease was 11.3%(9/80) after early preemptive therapy. Both univariate and multivariate analysis showed thymoglobulin (ATG) used in preconditioning regimen, other herpesvirus infection and fungal infection in medical history before NST were the risk factors of CMV infection after NST.Univariate analysis revealed that CMV viremia and ATG used in preconditioning regimen were the risk factors for CMV disease, while the same result was not found in the multivariate analysis.The incidence of CMV infection in patients with II-IV grade of aGVHD was 91.3%,while the incidence of CMV infection in patients with 0-1 grade of aGVHD was 71.9% (P = 0.06), it seems that II-IV grade of aGVHD was not the risk factor of CMV infection for NST. It is concluded that the ATG used in preconditioning regimen may increase the incidence of both CMV infection and CMV disease after NST. CMV infection easily accompanies by other herpesvirus infection and fungal infection.Therefore other herpesvirus infection and fungal infection should be attentively monitored and prevented after trans-plantation.