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  • American Society of Hematology  (16)
  • Chang, Ying-Jun  (16)
  • Liu, Kai-Yan  (16)
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  • American Society of Hematology  (16)
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  • 1
    In: Blood, American Society of Hematology, Vol. 138, No. Supplement 1 ( 2021-11-05), p. 1013-1013
    Abstract: Introduction Transplant-associated thrombotic microangiopathy (TA-TMA) is a severe complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT), with mortality over 80%. Effective management of TA-TMA is hampered by obscure pathogenesis and delayed diagnosis. There are no well-acknowledged therapeutic strategies for TA-TMA. TA-TMA-directed therapy includes therapeutic plasma exchange (TPE), eculizumab, rituximab, and defibrotide. The efficacy and outcome of TPE for the treatment of TA-TMA remain controversial. To our knowledge, this is the largest cohort to date of patients treated with TPE for TA-TMA after allo-HSCT. We aimed to identify predictors of response and mortality in patients with TA-TMA who received TPE, and to recognize patients who will benefit from TPE management. Methods A total of 6241 subjects who underwent allo-HSCT were performed at Peking University People's Hospital from January 2010 to December 2019, of whom 538 patients were diagnosed with TA-TMA, with a cumulative incidence of 8.6%. Among them, 82 consecutive critically ill TA-TMA patients received TPE. TA-TMA was diagnosed using the criteria proposed by Cho et al. TPE was not performed in a protocol-defined manner. Patients were classified as achieving complete response (CR) if they showed disappearance of schistocytes, resolution of any changes in mental status, normalization of lactic dehydrogenase, and were not receiving red blood cells and platelet transfusions. Patients were considered to have achieved no response (NR) when they showed no improvement of laboratory features, remained dependent on red blood cell and/or platelet transfusions, or died with active TA-TMA. Subjects were considered to have a partial response (PR) when they did not meet the criteria for either CR or NR (BMT 2010; Blood 2020). Results TA-TMA was diagnosed at a median time of 64.5 [IQR 38.8-158] days post-HSCT. The 42 men (51.2%) and 40 women (48.8%) had an average age of 35.3 years. Renal involvement (59.8%), central nervous system dysfunction (70.7%), gastrointestinal (GI) bleeding (73.2%), and concomitant acute graft-versus-host disease (aGVHD, 78%) were common in our cohort of TA-TMA patients. All 82 patients in our analysis received TPE, and adjunctive TA-TMA-targeted therapy included the use of rituximab (11 patients), rituximab plus eculizumab (1 patient), and defibrotide (1 patient). However, the additional therapy showed no significant difference between the response and nonresponse groups. The median time from TA-TMA to TPE initiation was 8 days [IQR 2.0-16.5], and the cumulative volume of TPE was 6 L [IQR 3.6-8.5] . Our data revealed that the overall response was 52.4% (43/82), comprising 4 CRs and 39 PRs. Early TPE initiation trended towards a better response, but this difference was not statistically significant. The multivariate analysis showed that patients with GI bleeding (OR, 6.26; 95% CI, 1.30-30.12), grade III-IV aGVHD (OR, 5.00; 95% CI, 1.50-16.68), lower cumulative volume of TPE (OR, 8.51; 95% CI, 1.91-38.05), and severe anemia (OR, 7.48; 95% CI, 2.20-25.49) were less likely to respond to TPE. Regarding treatment outcome, 57% (47/82) of cases survived 100 days post HSCT, and 20% (16/82) survived 100 days after the diagnosis of TA-TMA. With a median follow-up of 467 days [IQR 248-1002], the OS at 1 year after TA-TMA was 15%. The leading causes of death were infection, active TA-TMA, and multiple organ dysfunction syndrome (MODS). The Kaplan-Meier analysis showed that GI bleeding, grade III-IV aGVHD, and no response to TPE were associated with poor survival at 1-year post TA-TMA (Figure 1). By multivariate analysis, TA-TMA patients treated with TPE had dismal survival with GI bleeding, lower loading volume of TPE, and elevated total bilirubin. Conclusions The results of this large cohort of real-world practice indicate that TPE may be effective for TA-TMA depending on given clinical circumstances. Our data underscore that GI bleeding is independently associated with poor response to TPE and mortality, while grade III-IV aGVHD is again confirmed as predicting a dismal response to TPE. We hypothesize that higher volume of TPE is warranted to achieve resolution and favorable outcome of TA-TMA. Multicenter prospective studies are required to further verify whether these patients could benefit from TPE and seek a paradigm for TPE in the management of TA-TMA. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2021
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  • 2
    In: Blood, American Society of Hematology, Vol. 138, No. Supplement 1 ( 2021-11-05), p. 13-13
    Abstract: Introduction Immune thrombocytopenia (ITP) is an acquired, organ-specific, autoimmune disease and one of the most common bleeding disorders seriously endangering human health. Glucocorticoids and intravenous immunoglobulin are first-line treatments recommended by guidelines for patients with ITP. However, approximately 50%-85% of patients relapse during the first year of treatment. In addition, long-term use of glucocorticoids increases the risk for dose- and time-dependent glucocorticoid-related complications and serious side effects. Therefore, in-depth studies investigating new solutions for the first-line treatment of ITP are urgently needed. Tacrolimus is a calcineurin inhibitor, which forms a complex by binding to FK506-binding protein. It is currently widely used in the prevention of graft-versus-host disease for organ transplantation as well as for the treatment of autoimmune diseases. In addition to recent retrospective studies and case reports demonstrating its effectiveness in ITP, tacrolimus has been shown to improve anti-platelet antibody-mediated thrombocytopenia in mice, suggesting it may be a potential treatment for ITP. The aim of this study was to compare two first-line treatment options for ITP-a standard glucocorticoid-only regimen versus tacrolimus in combination with a standard glucocorticoid regimen-to determine which could help patients achieve stable platelet counts faster and experience a longer duration of remission. Methods This open-label, randomized, phase 2 trial, enrolled adult ITP patients from seven different tertiary medical centers in China. Elderly patients had confirmed, newly diagnosed, treatment-naive ITP, platelet counts & lt;30×10 9/L, or & lt; 50×10 9/L and significant bleeding symptoms (World Health Organization bleeding scale ≥ 2). Eligible patients were randomly assigned 1:1 with an interactive web-based response system to receive either oral tacrolimus (initial 0.03 mg/kg/day and maintain blood concentration at 3-5 ng/mL for 12 weeks) plus high-dose dexamethasone (HD-DXM) or HD-DXM monotherapy for 12 weeks. DXM (40 mg) was administered orally daily for 4 consecutive days to both study arms. The 4-day course of DXM was repeated on days 11-14 in patients who lacked response by day 10. The primary endpoint was 6-month sustained response (SR), defined as platelet count maintained & gt;50×10 9/L without any additional ITP-modifying therapy at the 6-month follow-up. Key secondary endpoints included initial response by day 14 (OR, platelet count ≥30×10 9/L and at least 2-fold increase in baseline platelet count and absence of bleeding; and CR, platelet count ≥ 100×10 9/L), duration of response, bleeding scores, and adverse events (AEs). This trial was registered with ClinicalTrials.gov (NCT04747080). Results Total 140 patients newly diagnosed with ITP were randomly assigned to either the tacrolimus plus HD-DXM (n=72) or HD-DXM monotherapy (n=68) groups. At the 6-month follow-up, the proportion of patients exhibiting SR was significantly higher in the tacrolimus plus HD-DXM group than in the HD-DXM monotherapy group (65.3% vs 42.6%, p= 0.007). Of the 140 patients with ITP (males accounted for 48.6%), the mean age was 32.8 years, the mean platelet count was 16.7×10 9/L. The combination group exhibited a higher 14-day early remission rate than the monotherapy group (76.4% vs 55.9%, P=0.001). Significantly fewer treatment failures occurred in patients randomly assigned to the combination group(19.4% vs 38.2%, P=0.0014). During the follow-up period, fewer patients in the combination group experienced relapse than in the monotherapy group; the median time to relapse was 77 days (Tacrolimus+HD-DXM) vs 36 days (HD-DXM). The combination group exhibited a lower proportion of bleeding events and a lower bleeding score. The incidence of serious AEs, rescue therapy, and treatment side effects were similar between the two groups, and treatment was well tolerated by all patients, with no grade 4 AEs or treatment-related deaths reported. There was no statistically significant difference in the incidence of treatment-related AEs between the two groups. Conclusions Low-dose tacrolimus plus HD-DXM was an effective and safe treatment for ITP as first-line therapy and elicited a sustained prolonged response in adults. This therapy may be a new treatment option for adult patients with ITP. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: It includes information or discussion of off-label drug use of tacrilimus.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2021
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    detail.hit.zdb_id: 80069-7
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  • 3
    In: Blood, American Society of Hematology, Vol. 132, No. Supplement 1 ( 2018-11-29), p. 5673-5673
    Abstract: Introduction: Graft-versus-host disease (GVHD) is a major complication of hematopoietic stem cell transplantation. Mesenchymal stem cells (MSCs) can modulate immune response and have been used as a treatment for aGVHD. The immune-modulating factors of MSCs are secreted and reside in supernatant fractions that are enriched for extracellular vesicles (EVs). MSC-derived EVs (MSC-EVs) also exhibit immunosuppressive activity, providing many advantages compared to MSCs and have been proven therapeutic in aGVHD. Arsenic trioxide (ATO) exhibits potent antitumor effects and increasing studies indicate its immunosuppressive effects. However, ATO at high concentrations can cause severe adverse effects. If encapsulated in some kind of drug vehicles, ATO can be made less toxic. Therefore, we believed that the combination of MSC-EVs with a low dose of ATO would be an effective therapy for aGVHD. Methods: We used a classical GVHD model (BALB/c→B6) and developed 4 groups: the control group (TCD-BM), the GVHD control group (TCD-BM + spleen T cells), the MSC-EVs treatment group and the MSC-ATO-EVs (MSC-derived ATO-encapsulating EVs) treatment group. OS, GVHD clinical and histological scores were evaluated. A20-luc lymphoma cells were injected to generate the GVL model. Using flow cytometry analysis, we analyzed Th cell subsets, cytokines and transcription factors (Th1*IFN-γ/TNF-α*T-bet, Th2*IL-4*GATA3, Th17*IL-17*RORγt, Treg*IL-10*Foxp3) and sorted CD8+ SLECs, and CD8+ MPECs in BM and spleen of recipients. Dll4 expression was analyzed on DCs. B6 cells were incubated with or without BALB/c spleen cells and complete medium alone, with 10 mM ATO alone. T cell apoptosis was determined with Yopro-1 staining. We used MLR assays to examine Th subsets, cytokines and notch targeted genes with or without ATO or neutralizing Ab specific to Dll4 (anti-Dll4). Results: BALB/c mice receiving B6 TCD-BM alone developed no sign of GVHD, whereas all BALB/c mice receiving B6 donor TCD-BM + spleen T cells died of GVHD. In contrast, injection of MSC-EVs and MSC-ATO-EVs inhibited GVHD in T cell recipients, with 20% and 29% of them surviving without severe GVHD, respectively. These survival rates were accompanied by significantly lower clinical and histological scores. GVL effects mediated by MSC-EVs and MSC-ATO-EVs were comparable to those obtained in the GVHD control group. Compared to the control group, CD4+T and CD8+T cells increased substantially in T cell recipients, resulting in severe GVHD. In contrast, treatment with MSC-ATO-EVs significantly reduced the number of CD4+T and CD8+T cells, while MSC-EVs recipients retained approximately the same number of T cells as the GVHD group. Compared to the GVHD control group, Th2 and Treg cells derived from the spleen increased, while Th1 and Th17 cells were reduced significantly in both the MSC-EVs and MSC-ATO-EVs groups. We also detected lower serum levels of TNF-α and IFNγ as well as lower expression of RORγt and T-bet in blood and BM CD4+ T cells in these two groups, while the expression of GATA3 and Foxp3 increased significantly. Treatment with MSC-ATO-EVs markedly raised the MPEC/SLEC ratio compared to the MSC-EVs and GVHD control groups. We also examined Dll4high DCs in different organs and different groups and found that only MSC-ATO-EVs significantly reduced the Dll4high DCs, especially in the spleen and intestine. Treatment of stimulated B6 CD4+ T and CD8+ T cells with ATO increased production of H2O2. Yopro-1 staining of activated B6 CD4+ T and CD8+ T cells indicated that ATO dramatically triggered apoptosis in those cells. DCs were isolated and cultured with B6 mouse-derived CD4+ T or CD8+ T cells, with or without addition of ATO or anti-Dll4. ATO and anti-Dll4 both led to significant reduction of IFN-γ and TNF-α, while IL-4 and IL-10 increased slightly. We next assessed the notch pathway targeted genes in T cells and found there were significantly increased GATA3 and reduced Dtx expression levels. Conclusion: Altogether, our findings demonstrate that MSC-ATO-EVs might be a highly promising therapy for aGVHD through reducing T cell amounts and modulating Th subsets and CD8+ T cell differentiation. These effects can be explained with the inhibition of the Dll4-notch pathway by ATO. Therefore, further exploitation of the potential application of ATO in aGVHD and the mechanisms of action of ATO may improve outcomes after allo-HSCT. Disclosures No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2018
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    detail.hit.zdb_id: 80069-7
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  • 4
    In: Blood, American Society of Hematology, Vol. 119, No. 23 ( 2012-06-07), p. 5584-5590
    Abstract: We report the results of a prospective, patient self-selected study evaluating whether haploidentical related donor stem cell transplantation (HRD-HSCT) is superior to chemotherapy alone as postremission treatment for patients with intermediate- or high-risk acute myeloid leukemia (AML) in first complete remission (CR1). Among totally 419 newly diagnosed AML patients, 132 patients with intermediate- and high-risk cytogenetics achieved CR1 and received chemotherapy alone (n = 74) or HSCT (n = 58) as postremission treatment. The cumulative incidence of relapse at 4 years was 37.5% ± 4.5%. Overall survival (OS) and disease-free survival (DFS) at 4 years were 64.5% ± 5.1% and 55.6% ± 5.0%, respectively. The cumulative incident of relapse for the HRD-HSCT group was significantly lower than that for the chemotherapy-alone group (12.0% ± 4.6% vs 57.8% ± 6.2%, respectively; P 〈 .0001). HRD-HSCT resulted in superior survival compared with chemotherapy alone (4-year DFS, 73.1% ± 7.1% vs 44.2% ± 6.2%, respectively; P 〈 .0001; 4-year OS, 77.5% ± 7.1% vs 54.7% ± 6.3%, respectively; P = .001). Multivariate analysis revealed postremission treatment (HRD-HSCT vs chemotherapy) and high WBC counts at diagnosis as independent risk factors affecting relapse, DFS, and OS. Our results suggest that HRD-HSCT is superior to chemotherapy alone as postremission treatment for AML.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2012
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  • 5
    In: Blood Advances, American Society of Hematology, Vol. 3, No. 24 ( 2019-12-23), p. 4312-4325
    Abstract: The rate and extent of natural killer (NK)–cell education after hematopoietic cell transplantation correlates with leukemia control. To study the effect of donor and host HLA on NK-cell reconstitution, single killer-cell immunoglobulin-like receptor (KIR)+ NK cells (exhibiting KIR2DL1, KIR2DL2/KIR2DL3, or KIR3DL1 as their sole receptor) were grouped into 4 groups based on the interaction between donor/host HLA and donor inhibitory KIR in 2 cohorts (n = 114 and n = 276, respectively). On days 90 to 180 after transplantation, the absolute number and responsiveness against K562 cells (CD107a or interferon-γ expression) of single-KIR+ NK cells were higher in pairs where donor and host HLA both expressed ligands for donor inhibitory KIRs than in pairs where 1 or both of the donor and recipient HLA lacked at least 1 KIR ligand. NK-cell responsiveness was tuned commensurate with the number of inhibitory receptors from the donor. When both donor and host expressed the 3 major KIR ligands (HLA-C1, HLA-C2, and HLA-Bw4), NK cells expressing 3 inhibitory receptors (KIR2DL1/2DL3/3DL1) reached the maximum responsiveness against K562 cells compared with those NK cells expressing only 1 or 2 inhibitory receptors. When donor and host HLA both expressed all ligands for donor inhibitory KIRs, patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) showed the lowest recurrence rate after haploidentical hematopoietic stem cell transplantation (haplo-HSCT). In conclusion, this study demonstrates that when both donors and hosts present all the KIR ligands for donor KIRs, reconstituted NK cells achieve better functional education and contribute to least relapse among patients. This observation study was registered at www.clinicaltrials.gov as #NCT02978274.
    Type of Medium: Online Resource
    ISSN: 2473-9529 , 2473-9537
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2019
    detail.hit.zdb_id: 2876449-3
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  • 6
    In: Blood, American Society of Hematology, Vol. 128, No. 22 ( 2016-12-02), p. 3323-3323
    Abstract: Objectives: SNPs of CTLA-4 have been shown to be important risk factors associated with autoimmune disease and malignancy , the objectives of this study were to explore the association of CTLA-4 SNPs with the development of myeloma and to evaluate the outcome of patients receiving bortezomib-based regimens in relation to CTLA-4 SNPs. Methods: Peripheral blood samples from 86 MM patients and 154 controls were obtained for the investigation of CTLA4 polymorphisms, The five SNP genotypes of CTLA-4, namely, -1772(rs733618),-1661 (rs4553808), -318 (rs5742909), CT60 (rs3087243), and +49 (rs231775), were determined by TaqMan SNP genotyping assays (Applied Biosystems) , Results: Some of the CTLA-4 polymorphisms display frequencies that are different among the different ethnic groups. The Kaplan-Meier analysis revealed that patients with rs733618 GG showed a significantly lower DFS (0% vs. 57.4%, P = 0.020) and OS (46.3% vs. 83.3%, P = 0.026) than those with GA+AA in MM patients after Botizomib based therapy. Multivariate analyses showed that rs733618 GG were risk factor for OS (HR= 0.025; 95% CI= 0.004-0.161;P=0.000). The incidence of nonhematologic grade 3/4 adverse events was significantly increased in the rs 4553808 GA+GG group compared to AA group(P=0.036). Conclusion: In summary, CTLA-4 rs733618 GG reduced the progression-free survival and overall survival in MM patients after Botizomib based therapy,knowledge of the CTLA-4 polymorphism and haplotype may provide useful information for MM therapy. The exact effect of the CTLA-4 polymorphism and haplotype on MM therapy outcome should be determined in different cohorts with substantially larger number of subjects. Correspondence: Professor X-J Huang, Peking University People's Hospital, Peking University Institute of Hematology, Beijing Key Laboratory of Hematopoietic Stem Cell Transplantation, Peking-Tsinghua Center for Life Sciences, 11 Xizhimen South Street, Beijing 100044, P.R. China. E-mail: huangxiaojun@bjmu.edu.cn The first 2 authors contributed equally to this work. Disclosures No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2016
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 7
    In: Blood, American Society of Hematology, Vol. 128, No. 22 ( 2016-12-02), p. 3385-3385
    Abstract: Licensed NK cells have been demonstrated to have anti-cytomegalovirus (CMV) activity. We prospectively analysed the HLA typing of donor-recipient pairs and the KIR typing of the donors in 180 leukaemia patients to assess the predictive roles of licensed NK cells and donor-activating KIR genes on CMV reactivation post-T cell-replete haplo-SCT. Multivariate analysis showed that donor and recipient KIR ligand-ligand graft-versus-host direction or host-versus-graft direction mismatch were associated with the incidence of CMV reactivation [HR=1.663, 95%CI, 1.161-2.383, P=0.006] and refractory CMV infection [HR=2.34, 95%CI, 1.28-4.27, P=0.006] post-haploidentical T cell-replete transplantation. Donor and recipient KIR ligand-ligand match decreased CMV reactivation (51.65% [46.67, 56.62%] vs. 75.28% [70.87, 79.69%] , P=0.012), refractory CMV infection (17.58% [13.77, 21.40%] vs. 35.96% [31.09, 40.82%] , P=0.004) and CMV disease (3.30% [1.51, 5.08%] vs. 11.24% [8.04, 14.43%] , P=0.024), respectively. Meanwhile, there was a significantly increased risk of CMV reactivation in patients who accepted a KIR2DS2-positive donor compared those who accepted a KIR2DS2-negative donor (80% [71.93, 88.07%] vs. 63.87% [60.18, 67.56%] , P=0.039), especially in recipient HLA-C1/C2 and donor HLA-C1C2 with KIR2DL1/2DL2/2DL3/2DS2 genotype (100%). Conclusions: These findings suggested that donor and recipient KIR ligand-ligand match might promote the NK cell licensing process, thereby increasing NK cell-mediated protection against CMV reactivation. However, roles of donor positivity for the KIR2DS2 against CMV reactivation need to be further explored in T cell-replete haplo-SCT. Disclosures No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2016
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 8
    In: Blood, American Society of Hematology, Vol. 132, No. Supplement 1 ( 2018-11-29), p. 3769-3769
    Abstract: Introduction Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by abnormal immune response. Though many therapies have been used, corticosteroid-resistance remains to be a challenge clinically. Extensive research has improved our understanding of ITP, showing that environmental factors affect the disease profile, such as Helicobacter pylori being proven to be associated with thrombocytopenia. Though evidence that the gut microbiota contributes to the development of auto-immune disorders is accumulating, there is no information available on relationship between gut microbiome and ITP. Berberine(BBR), a traditional compound isolated from a Chinese herb, has been widely used as a nonprescription drug to treat diarrhea. Recently, BBR has been reported to modulate microbiota structures, which contributes to improving metabolic disorders. Here, we hypothesized that BBR might modulate gut microbiota to treat ITP. Methods In order to investigate the relationship between gut microbiome and ITP, we performed deep shotgun sequencing on 253 fecal samples totally from consecutive ITP patients and healthy controls. Metagenome-wide association study (MWAS) was conducted, and clinical characteristics of patients were collected to analyze the correlation with gut microbiome (Nan Qin, et al. Nature. 2012). Certainly, a clinical cohort study was performed to assess the efficacy of BBR in corticosteroid-resistant ITP patients. To better characterize the role of gut microbiota in the development of ITP and to verify the modulating effect of BBR on gut microbiota structure, we performed colonization of mice with specific bacterium and established active murine models (immunized-splenocyte engraftment) of BBR treatment. Result We integrated the sequencing data into an existing gut microbial reference-gene catalog and identified 35275 genes that differ in abundance between ITP patients and healthy controls. We then clustered the genes into metagenomic species (MGS) and finally identified 15 MGS which were significantly different in both discovery cohort and validation cohort. Dysbiosis was detected in the gut microbiome of ITP patients, as both phylogenetic analysis and MGS annotation indicated that Lachnospiraceae bacterium, Clostridium asparagiforme were over-represented while Bacteroides spp was depleted in ITP patients comparing with healthy controls. Functionally, KEGG annotation showed that the most enriched orthologs in ITP patients were related to membrane transport. Moreover, the biosynthesis of microbe-associated molecular patterns (MAMPs) such as lipopolysaccharides (LPS), peptidoglycan biosynthesis and flagellin were highly abundant in patients. Gene biomarkers and cluster markers based on gut microbiome were established to identify ITP patients and were validated in an independent cohort. The alterations of gut microbiome in ITP patients are partly reversed after treatment. Furthermore, L. bacterium shows more abundant in corticosteroid-resistant ITP comparing with newly diagnosed ITP. Specifically, BBR treatment could improve the microbial dysbiosis of corticosteroid-resistant ITP patients, the complete response (CR), response(R), and overall response (OR) rates being 26.3%, 47.4% and 73.7%, respectively. Targeted QPCR assay determined that L. bacterium accumulated in corticosteroid-resistant ITP, consistent with the result of shotgun sequencing data. Gavage with L. bacterium results in significantly alterations of gut microbiota structure in mice comparing with mice without bacterial administration or those receiving Clostridium asparagiforme administration. Moreover, colonization of L. bacterium caused more severe thrombocytopenia and impaired the response to corticosteroid therapy in active ITP model. Intriguingly, BBR treatment, but not any other antibiotics, could reverse the effect of L. bacterium colonization on gut microbiota structure and enhance the response to corticosteroid therapy. Conclusion Our findings demonstrate that the gut microbiome alters in ITP and is partly normalized after treatment. Gut microbiota dysbiosis may contribute to the development of corticosteroid-resistant ITP. BBR may correct corticosteroid-resistance by modulating the gut microbiota structure, thus being a novel potential second-line candidate to treat ITP. Disclosures No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2018
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 9
    In: Blood, American Society of Hematology, Vol. 116, No. 21 ( 2010-11-19), p. 2312-2312
    Abstract: Abstract 2312 Unmanipulated human leukocyte antigen (HLA)-mismatched/haploidentical trasnplantation is an established treatment for patients without HLA-matched related or unrelated donors. In contrast to HLA-matched transplant, intensified immnological suppression, including antithymocyte globulin was used to overcome the HLA barrier. However, it is currently unclear how this radically different transplantation strategy affect immunological recovery. To investigate the immune reconstituion following unmanipulated human leukocyte antigen (HLA)-mismatched/haploidentical trasnplantation and HLA-matched transplantation. Seventy-five patients underwent transplantation from either HLA-identical siblings (25 cases) or haploidentical donors (50 cases) were enrolled in this prospective study. Recovery of T-, B-, monocytes, and dendritic cell subsets, proliferative of T lymphocytes in vitro response to mitogens, were investigated. Our results showed that in the first 90 days after grafting, counts of the following T cell subsets were signifcantly lower in haploidentical transplant recipients than those of HLA-matched transplant recipients: total CD4+ T cells, and their CD45RA positive (naïve), CD45RO (memory) subpopulation. After this interval, increases in CD4+, CD4+ naïve, and CD4+ memory T cell counts were observed in surviving subjects, by 1 year after transplantation, there were no differences in the numbers of recovered CD4+, CD4+ naïve, and CD4+ memory T cells between patients receiving haploidentical transplant and those receiving HLA-identical transplantation. In contrast, total counts of CD8+ T cells declined after conditioning and were significantly reduced by day 30 post-haploidentical transplantation. Thereafter, absolute of CD8+ T cell numbers expanded dramatically, and were signifciantly higher than that of HLA-identical recipients since day 90 post transplantation time point (Figure). CD3+ cells, CD8+ naïve, and CD8+ memory T cells were comparable by 90 days after transplantation, although lower numbers of these cells were found in haploidentical group prior day 90 after grafting. Furthermore, the ratio of CD4/CD8 T cells was significantly inverted in both groups untill 1 year after transplantation. While monocytes recovered promptly and reached normal levels by day 15 after haploidentical transplantation, though they also declined slightly by the 1 year time point, at which CD4+ T cell counts rebounded. These results indciate that quantitative CD4+ T-cell recovery is delayed after haploidentical transplantation, they also suggest that compensatory expansion of cytotoxic T lymphocytes and monocytes may accompany CD4+ T lymphopenia. Subsets of DC, including myeloid DC 1 (MDC1), MDC2 and plasmacytoid DC (pDC), in haploidentical recipients on day 15, and day 30 post allografting were significantly lower than those in HLA-matched recipients. No sigificant difference in the counts of B cells at any time point after transplantation in haploidentical recipients and HLA-matched recipients were found. On day 15 after transplantation, the expression of CD28 on CD8+ T cells was sigificantly lower in patients receiving haploidentical transplantation, then increased promptly and signifcantly higher than those receiving HLA-matched transplant on day 30, and 90, after this two time point the expression of CD28 were comparable between two groups. Moreover, the expression of CD28 on CD4+ T cells was also signifcantly higher than those receiving HLA-matched transplant on day 30, and 90. While only at days 30 post transplant, the expession of CD80 on pDC were signifcantly higher in patients receiving haploidentical transplant and than those receiving HLA-identical transplantation. The ability of the patient-derived T cells to produce IFN-Ã and IL-4 by day 30 after transplantation was similar in in patients without aGVHD between haploidentical transplant recipients and HLA-matched recipients. Our results suggest that comparable immune reconstitution could be achieved folloing hapolidentical transplantation and HLA-matched transplantation, this is related to the similar transplant outcomes. Fig The capability of T cells to produce IFN-Ã and IL-4 in patients without aGVHD between HLA-matched transplantation (the former box) and haploidentical transplantation (the latter box). Fig. The capability of T cells to produce IFN-Ã and IL-4 in patients without aGVHD between HLA-matched transplantation (the former box) and haploidentical transplantation (the latter box). Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2010
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 10
    In: Blood, American Society of Hematology, Vol. 128, No. 22 ( 2016-12-02), p. 165-165
    Abstract: Immune thrombocytopenia (ITP) is a common autoimmune disorder characterized by increased bleeding tendency and isolated thrombocytopenia. The precise pathogenesis of the decreased thrombopoiesis in chronic ITP (cITP) is poorly understood. Megakaryocytes (MKs) in cITP show impaired maturation and thrombopoiesis, which are correlated with numerous glycoproteins on the surface of MKs. Different types of sialoglycoproteins are expressed on the surface of megakaryocytes, including GPIbα and platelet endothelial cell adhesion molecule-1 (PECAM-1), both of which participate in megakaryocyte migration to the vascular niche in the bone marrow (BM) and in proplatelet formation. Desialylation has recently been identified a contributor to the pathogenesis of thrombocytopenia. Our previous study has demonstrated that desialylation of GPIbα is related to increased apoptosis and phagocytosis of platelets in cases of prolonged isolated thrombocytopenia after allogeneic hematopoietic stem cell transplantation (Zhang et al., J Hematol Oncol, 2015). Because MKs are heavily sialylated cells, we raised the question whether the desialylation of megakaryocytes contributes to the defective thrombopoiesis in patients with cITP through impaired MK migration, adhesion and proplatelet formation in the vascular niche. MK desialylation was analyzed by flow cytometry using lectins. Desialylated glycoproteins were measured using selective exo-enzymatic labeling. Protein expression, distribution and interaction were measured using the following techniques: immunofluorescence, flow cytometry, western blot and immunoprecipitation. cITP MKs exhibited increased β-galactose exposure compared to the control MKs, indicating excessive desialylation. Desialylation was correlated with decreased platelet production of MKs. We further explored the cause of desialylation and found that the sialidase NEU1 was over-expressed in MKs. Treatment with the sialidase inhibitor DANA ameliorated the loss of sialic acids. These results indicated that NEU1 contributed to the desialylation of MKs in cITP. Altered MK distribution in the BM niche was exhibited upon BM biopsy of cITP patients. The ratio of perivascular MKs was markedly decreased in cITP patients. Defective adhesion and transmigration behaviors were also discovered in desialylated cITP MKs. The motility of cITP MKs through stromal cell monolayers driven by stromal cell derived factor 1 (SDF1) was decreased. Adherence to fibronectin, collagen and fibrinogen was assessed, and desialylated cITP MKs exhibited an increase in adhesion with these macromolecules. Similar abnormalities were observed in the BM niche of ST6Gal1-/- mice, and treatment with ST6Gal1 and CMP-SA augmented the ratio of MKs in the BM vascular niche in ST6Gal1-/-mice, indicating that desialylation impaired the MK migration and adhesion. Additional experiments focused on which specific sialoglycoproteins are excessively desialylated. As detected by SEEL, PECAM-1 exhibited excessive desialylation in cITP MKs, which was related to impaired CXCR4 polarization in response to SDF1. Inhibition of sialidase using DANA partially restored this polarization, demonstrating that desialylation of PECAM-1 was responsible for the defect in MK migration to the vascular niche. Meanwhile, PECAM-1 desialylation was associated with GPIIb/IIIa overactivation, which correlated to the increased adhesion of MKs. This increased adhesion was reversed by the GPIIb/IIIa inhibitor lotrafiban, indicating that desialylated PECAM-1 contributed to the abnormal adhesion via overactivation of GPIIb/IIIa. Desialylation of GPIbα was found on the surface of MKs from cITP patients and was associated with abnormal microtubule formation and increased MK apoptosis through altered 14-3-3ζ distribution, which led to the impediment of proplatelet formation in the vascular niche. In conclusion, our results demonstrate that MKs are desialylated by NEU1 in cITP patients, and desialylated MKs present with defective migration towards the vascular niche, abnormal adhesion to the extracellular matrix and impaired proplatelet formation. Desialylation of PECAM-1 and GPIbα have been demonstrated to be responsible for these abnormal behaviors of MKs. Sialidase inhibitor shows an improvement in the thrombopoiesis of cITP MKs; therefore, our study implies a novel potential approach for the treatment of cITP. Disclosures No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2016
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
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