Key Points• We developed an approach of T-cell-replete haploidentical HSCT with low-dose anti-T-lymphocyte globulin.• Outcomes of suitably matched URD-HSCT and HRD-HSCT are similar, and HRD-HSCT improves outcomes of patients with high-risk leukemia.We developed an approach of T-cell-replete haploidentical hematopoietic stem cell transplantation (HSCT) with low-dose anti-T-lymphocyte globulin and prospectively compared outcomes of all contemporaneous T-cell-replete HSCT performed at our center using matched sibling donors (MSDs), unrelated donors (URDs), and haploidentical related donors (HRDs). From 2008 to 2013, 90 patients underwent MSD-HSCT, 116 underwent URD-HSCT, and 99 underwent HRD-HSCT. HRDs were associated with higher incidences of grades 2 to 4 (42.4%) and severe acute graft-versus-host disease (17.2%) and nonrelapse mortality (30.5%), compared with MSDs (15.6%, 5.6%, and 4.7%, respectively; P < .05), but were similar to URDs, even fully 10/10 HLA-matched URDs. For high-risk patients, a superior graft-versus-leukemia effect was observed in HRD-HSCT, with 5-year relapse rates of 15.4% in HRD-HSCT, 28.2% in URD-HSCT (P 5 .07), and 49.9% in MSD-HSCT (P 5 .002). Furthermore, 5-year disease-free survival rates were not significantly different for patients undergoing transplantation using 3 types of donors, with 63.6%, 58.4%, and 58.3% for MSD, URD, and HRD transplantation, respectively (P 5 .574). Our data indicate that outcomes after HSCT from suitably matched URDs and HRDs with low-dose anti-Tlymphocyte globulin are similar and that HRD improves outcomes of patients with high-risk leukemia. This trial was registered at www.chictr.org (Chinese Clinical Trial Registry) as #ChiCTR

Patients with relapsed/refractory acute lymphocytic leukemia (R/R ALL) have a poor prognosis. Chimeric antigen receptor-modified T cells against CD19 (CART19) have displayed anti-leukemia activities. However, data from systemic trials in Chinese patients are limited. T cells transduced with CD19-directed CAR lentiviral vectors were infused in patients with R/R ALL under fludarabine- and cyclophosphamide-based lymphodepletion. The postinfusion responses, toxicities, expansion, and persistence of CART19s in enrolled patients were observed and monitored. We enrolled 15 patients with R/R ALL. The median transduction efficiency of CART19s was 33%. cytotoxicity assays were conducted and showed prominent antileukemia activities with CART19s. The patients received CART19s infusion at doses of 1.1 × 10/kg to 9.8 × 10/kg. Twelve patients achieved complete remission 1 month after CART19s infusion. CART19s expanded and persisted in peripheral blood and bone marrow. At 150 days, the overall survival rate and leukemia-free survival rate were 65.5% and 37.8%, respectively. The cumulative incidence of relapse and the nonrelapse mortality rate were 54.5% and 7.7%, respectively. Four patients underwent subsequent haploidentical hematopoietic stem cell transplantation. In this trial, 10 patients experienced cytokine release syndrome (CRS). Grade 3 CRS developed in 40% of patients and was associated with a higher disease burden on day -1 and a higher number of previous relapses. This trial demonstrated potent antileukemia activities of CART19s in Chinese patients with R/R ALL. Disease relapse remained the main obstacle. However, patients with a high risk of relapse after CART19s might benefit from subsequent haploidentical hematopoietic stem cell transplantation. .

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative therapy for both malignant and nonmalignant hematologic disorders. However, primary poor graft function (PGF) is a serious early complication of allo-HSCT that leads to a poor outcome. Little is known about the characteristics, incidence, and risk factors of primary PGF occurring after allo-HSCT. Here we performed a 1:4 ratio nested case-control study in 830 patients who underwent allo-HSCT between April 2013 and November 2018 at our center. Twenty-four patients (14 males and 10 females; average age, 35.79 years; range, 17 to 53 years) developed primary PGF. On univariate and multivariate analyses, a CD34 + cell dose <5 £ 10 6 /kg (P = .003), a serum ferritin (SF) level >2000 ng/mL (P = .008), and splenomegaly (P = .039) were identified as 3 independent risk factors for primary PGF. After a median follow-up of 7.5 months (range, 1 to 48 months), only 5 patients (20.8%) survived. The survival rate of patients with primary PGF was significantly lower than that of patients with good graft function (GGF) (1-year overall survival, 25.0% versus 90.6%; P < .001). Cox regression analysis suggested that PGF and high SF level were strongly associated with rapid death in these patients. In conclusion, allo-HSCT recipients with a low CD34 + cell dose in their graft and exhibiting a high SF level and splenomegaly should be monitored for the development of primary PGF after allo-HSCT, and effective therapies need to be explored.

Background: Consolidative allogeneic hematopoietic stem cell transplantation is a controversial option for patients with relapsed/refractory acute lymphoblastic leukemia after chimeric antigen receptor T cell (CAR-T) therapy. We performed a multicenter retrospective study to assess whether patients can benefit from haploidentical hematopoietic stem cell transplantation after CAR-T therapy.Methods: A total of 122 patients after CAR-T therapy were enrolled, including 67 patients without subsequent transplantation (non-transplant group) and 55 patients with subsequent haploidentical hematopoietic stem cell transplantation (transplant group). Long-term outcome was assessed, as was its association with baseline patient characteristics. Results: Compared with the non-transplant group, transplantation recipients had a higher 2-year overall survival (OS; 77.0% versus 36.4%; P < 0.001) and leukemia-free survival (LFS; 65.6% versus 32.8%; P < 0.001). Multivariate analysis showed that minimal residual disease (MRD) positivity at transplantation is an independent factor associated with poor LFS (P = 0.005), OS (P = 0.035), and high cumulative incidence rate of relapse (P = 0.045). Pretransplant MRD-negative recipients (MRD− group) had a lower cumulative incidence of relapse (17.3%) than those

Donor cell leukemia after allogeneic hematopoietic stem cell transplantation might provide a unique human model for our understanding of leukemogenesis in vivo. We hypothesized that the "2-genetic-hits model" may contribute to the "leukemization" of donor cells and first evaluated these genetic mutations that are implicated in the development of acute myeloid leukemia in a donor cell leukemia patient and donor. The patient and his donor-sister both harbored a germline mutation in CEBPA (584_589dup). Susceptible donor hematopoietic cells evolved to overt acute myeloid leukemia by developing 2 somatic CEBPA mutations (247dupC and 914_916dup) in the patient's microenvironment. These were identical to the acquired mutations identified in leukemic cells that originated from the patient during de novo acute myeloid leukemia. Our results provide the first report of multiple mutations of CEBPA contributing to the transformation of donor cells to the leukemic phenotype and provide clues to support the multiplegenetic-hits mechanism of donor cell leukemia. (Blood. 2011;117(19):5257-5260) IntroductionLeukemia relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) that arises in cells of donor origin in the transplant recipient, so-called donor cell leukemia (DCL), is a rare disease entity, and only 51 cases were reported since 1971. [1][2][3][4] The precise etiologic mechanisms of DCL remain unknown, and no common mechanism can be identified in most of the cases reported in the literature. Careful analysis of the mechanisms with respect to the oncogenic transformation of donor-derived cells might provide a unique human model for our understanding of leukemogenesis in vivo.According to the "2-genetic-hits model," cooperation between 2 classes of genetic mutations contributes to leukemogenesis. 5 One group (class 1) comprises mutations in the fms-related tyrosine kinase 3 gene (FLT3) or the neuroblastoma RAS viral oncogene homolog gene (NRAS), which increase the proliferation and/or survival of hematopoietic stem/progenitor cells. 6,7 The other complementation group (class 2) comprises mutations in CEBPA, the gene that encodes the CCAAT enhancer-binding protein␣ (C/EBP␣); the myeloid-lymphoid or mixed-lineage leukemia gene (MLL); or the nucleophosmin gene (NPM1), which cause impaired differentiation. [8][9][10] The most common mutations, which include internal tandem duplications restricted to exons 14 and 15 and point mutation of Asp 835 within the TK domain of FLT3, codon 12/13 in exon 1 and codon 61 in exon 2 of NRAS, the entire coding region of CEBPA, partial tandem duplications that span exons 2-6 or exons 2-8 of MLL, and mutations in exon 12 of NPM1, have been described extensively in acute myeloid leukemia (AML). [11][12][13][14] We hypothesized that the 2-genetic-hits model may contribute to the "leukemization" of donor cells in DCL. We screened these genetic mutations implicated in the development of common forms of AML in a DCL patient and donor. MethodsThe study was approved by the Zhejiang U...

Hematopoietic stem cells (HSCs) produce all lineages of mature blood cells for the lifetime of an organism. In vertebrates, HSCs derive from the transition of the hemogenic endothelium (HE) in the floor of the embryonic dorsal aorta. Most recently, a series of proinflammatory factors, such as tumor necrosis factor-α, interferon-γ, and Toll-like receptor 4, have been confirmed to play a key role in HSC specification. However, the full complement of necessary signaling inputs remains unknown to date. Here, we show that interleukin-6R (IL6R) via IL6 is required and sufficient for HSC generation. We found that Notch activates IL6R by regulating its expression in the HE and in HSCs. The secretion of IL6 mainly originates from HSC-independent myeloid cells, but not from HSCs and their adjacent vascular endothelial cells. In addition, blocking IL6 signaling does not affect vascular development or the production of primitive erythrocytes. Taken together, our results uncover a previously obscure relationship between IL6 signaling and HSC production and provide new insights into HSC regeneration using proinflammatory factors in vitro.

Transplantation-associated thrombotic microangiopathy (TA-TMA) is a significant complication of haematopoietic stem cell transplantation. However, it remains controversial which clinical or laboratory markers are of evident risk and prognostic value. From 2006 to 2013, a nested case control study was carried out in our centre to study the risk and prognostic factors of TA-TMA. A total of 654 consecutive patients who underwent allogeneic haematopoietic stem cell transplantation were studied. Twenty-six (4.0%) patients matched the established diagnostic criteria. Subjects with TA-TMA had significantly higher 3-year none relapse mortality compared with those without (65.4% vs 15.4%, P < 0.0001). Grades 2 to 4 aGVHD and cytomegalovirus viremia were independent risk factors, and serum LDH level >500U/L as well as hypertension were early signs of TA-TMA occurrence. Liver dysfunction and significant gastric bleeding were independent risk factors for TA-TMA related mortality. Subjects with either liver dysfunction or significant gastric bleeding had significantly higher 3 year TA-TMA related mortality cumulative incidence than subjects without. These observations lead to the conclusion that allo-HSCT recipients with grades 2 to 4 aGVHD or cytomegalovirus viremia should be monitored for TA-TMA. Liver dysfunction and significant gastric bleeding are prognostic factors for TA-TMA. Copyright © 2016 John Wiley & Sons, Ltd.

Acute graft versus host disease (aGVHD) remains a major problem after allogeneic hematopoietic stem cell transplantation. Standard frontline therapy for aGVHD involves corticosteroids. However, fewer than half of patients have a lasting complete response. The long-term mortality rate of steroid-refractory aGVHD (SR-aGVHD) remains around 70%. To date, no consensus has been reached regarding the optimal salvage treatment for SR-aGVHD. We performed the first prospective, multi-center clinical trial to assess the efficacy and safety of a novel approach to treat severe (grades III-IV) SR-aGVHD with the combination of basiliximab and etanercept. Sixty-five patients with severe SR-aGVHD from six centers were included. The median number of basiliximab infusions was 4 (range 2-11) and of etanercept was 9 (range 2-12). At day 28 after starting the combination treatment, overall response (complete and partial response: CRCPR) to second-line treatment was 90.8% with 75.4% being CR. The incidences of CR per organ were 100%, 73.8%, and 79.7% for skin, liver, and gut involvement, respectively. Patients >30-y old (p D 0.043, RR D 3.169), development of grades III-IV liver aGVHD (p D 0.007, RR D 5.034) and cytomegalovirus (CMV) reactivation (p D 0.035, RR D 4.02) were independent predictors for incomplete response. Combined treatment with basiliximab and etanercept resulted in improved CR to visceral aGVHD and significantly superior 2-y overall survival (54.7% vs. 14.8%, p <0.001) compared with classical salvage treatments. Our data suggest that the combination of basiliximab and etanercept may constitute a promising new treatment option for SR-aGVHD.