Impact of a novel prognostic model on allogeneic hematopoietic stem cell transplantation outcomes in patients with CMML.

Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell malignancy, and allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curable treatment. The outcomes after transplant are influenced by both disease characteristics and patient comorbidities. To develop a novel prognostic model to predict the post-transplant survival of CMML patients, we identified risk factors by applying univariable and multivariable Cox proportional hazards regression to a derivation cohort. In multivariable analysis, advanced age (hazard ratio [HR] 3.583), leukocyte count (HR 3.499), anemia (HR 3.439), bone marrow blast cell count (HR 2.095), and no chronic graft versus host disease (cGVHD; HR 4.799) were independently associated with worse survival. A novel prognostic model termed ABLAG (Age, Blast, Leukocyte, Anemia, cGVHD) was developed and the points were assigned according to the regression equation. The patients were categorized into low risk (0-1), intermediate risk (2, 3), and high risk (4-6) three groups and the 3-year overall survival (OS) were 93.3% (95%CI, 61%-99%), 78.9% (95%CI, 60%-90%), and 51.6% (95%CI, 32%-68%; p < .001), respectively. In internal and external validation cohort, the area under the receiver operating characteristic (ROC) curves of the ABLAG model were 0.829 (95% CI, 0.776-0.902) and 0.749 (95% CI, 0.684-0.854). Compared with existing models designed for the nontransplant setting, calibration plots, and decision curve analysis showed that the ABLAG model revealed a high consistency between predicted and observed outcomes and patients could benefit from this model. In conclusion, combining disease and patient characteristic, the ABLAG model provides better survival stratification for CMML patients receiving allo-HSCT.

Soluble extracellular domains of human SIRPα and CD47 expressed in Escherichia coli enhances the phagocytosis of leukemia cells by macrophages in vitro.

Signal regulatory protein (SIRP) α, a transmembrane protein belonging to the immunoglobulin superfamily, is a receptor for CD47. The interaction between SIRPα and CD47 plays an important role in regulating the phagocytosis of leukemia cells and leukemia stem cells (LSCs) by macrophages. Blocking antibodies against CD47 have been shown to promote phagocytosis of LSCs by macrophages. Here, we consider an alternative way to interrupt the interaction between CD47 and SIRPα. We expressed the extracellular domains of the human SIRPα (hSIRP(ext)) and the human CD47 (hCD47(ext)) in Escherichia coli as Trx fusion proteins, and purified them by using affinity chromatography. We show that the purified fusion protein Trx-SIRP(ext) could interact in vitro with Trx-hCD47(ext). Moreover, Trx-SIRP(ext) could effectively bind to Jurkat T-ALL cells, which expressed CD47 at a high level. CD47(ext), on the other hand, bound to human macrophages. In vitro phagocytosis assay showed that these fusion proteins could enhance the phagocytosis of Jurkat cells by macrophage, with Trx-hSIRP(ext) showed a higher efficiency than Trx-CD47(ext). These results indicated that the soluble Trx-hSIRP(ext) and Trx-CD47(ext) polypeptides could be alternative molecules to interrupt CD47-SIRPα interaction between leukemia cells and macrophages, and might be potentially useful for the targeted therapy of leukemia.

[Clinical Outcomes and Prognostic Factors of Allogeneic Hematopoietic Stem Cell Transplantation in the Treatment of Refractory/Relapsed Acute Myeloid Leukemia].

OBJECTIVE: To investigate the clinical outcomes and prognostic factors of refractory/relapsed acute myeloid leukemia (AML) patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: The clinical data of 80 refractory/relapsed AML patients who received allo-HSCT from December 2013 to June 2020 were retrospectively analyzed, including the overall survival (OS) rate, disease-free survival (DFS) rate, relapse rate, incidence of transplant-related mortality (TRM), and the related risk factors were explored. RESULTS: Hematopoietic reconstitution was obtained in all 80 patients after transplantation, the 3-year OS and DFS rates were (48.8±6.3)% and (40.8±6.7)%, respectively. The 3-year cumulative incidence of relapse and TRM were 33.8% (95%CI: 0.254-0.449) and 15.0%(95%CI: 0.114-0.198), respectively. Univariate analysis showed that non-remission (NR) status before transplantation, DNMT3A R882 mutations and grade II-IV acute graft-versus-host disease (aGVHD) had negative effects on OS and DFS. Multivariate analysis indicated that the DNMT3A R882 mutations and grade II-IV aGVHD were independent risk factors for OS (HR=0.253, 95%CI: 0.092-0.695, P=0.008; HR=5.681, 95%CI: 2.101-15.361, P=0.001) and DFS (HR=0.200, 95%CI: 0.071-0.569, P=0.003; HR=7.117, 95%CI: 2.556-19.818, P<0.001). The 3-year cumulative incidence of relapse was 71.4%(95%CI: 0.610-0.836) in genetic high-risk group, which was higher than 23.3%(95%CI: 0.147-0.370) in intermediate-risk group and 23.5%(95%CI: 0.127-0.437) in favorable-risk group (P=0.006). CONCLUSION: Allo-HSCT is an effective and safe choice for refractory/relapsed AML patients. DNMT3A R882 mutations and grade II-IV aGVHD are negative prognostic factors of allo-HSCT for refractory/relapsed AML patients.

[Clinical Efficacy of Autologous Hematopoietic Stem Cell Transplantation for Patients with Diffuse Large B-Cell Lymphoma].

OBJECTIVE: To compare the clinical efficacy of first-line and salvage autologous hematopoietic stem cell transplantation (auto-HSCT) in the treatment of patients with diffuse large B-cell lymphoma (DLBCL). METHODS: The clinical data of 30 patients with DLBCL aged≤60 years old were retrospectively analyzed, and the patients were divided into first-line auto-HSCT group (15 cases) and salvage auto-HSCT group (refractory relapsed patients, 15 cases) according to the timing of transplantation, and the efficacy was analyzed. Anyone of the factors must be followed in patients receiving first-line HSCT: aaIPI score≥2 points, Ann-Arbor stage III-IV, large mass (diameter≥10 cm) or double expression of c-myc/BCL-2. RESULTS: The median follow-up time for all patients after transplantation was 26 (3-103) months. Until the end of follow-up, 23 patients survived and 7 patients died. All the 7 dead patients with multiple organ failure due to the relapse and disease progression. The median survival time of 7 dead patients from transplantation to death was 6 (3-11) months. Among the 15 patients in the first-line auto-HSCT group, there were 2 patients relapsed (13.3%), 1 dead (6.7%), 14 patients survived [overall survival (OS) rate was 93.3%]. Among the 15 patients treated with salvage auto-HSCT, 6 patients died due to disease progression or relapse (40%), 9 cases survived (OS rate was 60%). There was a statistically significant difference in the mortality of patients between the two groups (6.7% vs 40%, P=0.006). The 3-year PFS and OS rates of patients in first-line auto-HSCT group were both 93.3%. The 3-year PFS and OS of patients in salvage auto-HSCT group were 58.7% and 59.2%. The 3-year OS and PFS of patients in the first-line auto-HSCT group were significantly higher than those in the salvage auto-HSCT group (P=0.03, P=0.04). The bone marrow suppression was the most common adverse complication and all patients showed grade III-IV granulocytopenia. Non-hematological adverse reactions were mainly gastrointestinal adverse reactions and oral mucositis. There was no statistically significant difference in adverse reactions between the two groups. CONCLUSION: First-line auto-HSCT can be used as a consolidation treatment for DLBCL patients with poor prognostic factors. Auto-HSCT can further improve the prognosis of salvage chemotherapy-sensitive patients with refractory relapsed DLBCL.

[Comparison of Frontline Haploidentical Hematopoietic Stem Cell Transplantation and Salvage Haploidentical Hematopoietic Stem Cell Transplantation for Patients with Severe Aplastic Anemia].

OBJECTIVE: To compare the clinical efficacy between frontline haplo-identical hematopoietic stem cell transplantation (haplo-HSCT) and salvage haplo-HSCT for patients with severe aplastic anemia (SAA). METHODS: A total of 39 patients with severe aplastic anemia or very severe aplastic anemia from May 1st, 2013 to December 31st, 2018 were analyzed retrospectively. All of them underwent bone marrow + peripheral blood hemopoietic stem cell transplantation. There were 20 cases who accepted frontline haplo-HSCT for a median course of 1 (1-3) month, and 19 cases who accepted salvage haplo-HSCT for a median course of 72 (6-168) months. Conditioning regimen: 22 cases received Flu/Cy+ATG, and 17 cases received Bu/Cy+ATG. RESULTS: The time of hematopoietic reconstitution, infection rate, and grade I-Ⅱ and Ⅲ-Ⅳ acute/chronic graft versus host disease showed no statistically significance between the frontline haplo-HSCT group and the salvage haplo-HSCT group. In the frontline haplo-HSCT group, 1 case (5%) failed in second engraftment, in the salvage haplo-HSCT group 2 cases (10.5%) failed in primary engraftment and 4 cases (21.1%) in second engraftment. The incidence of engraftment failure was higher in the salvage haplo-HSCT group than that in the frontline haplo-HSCT group (P=0.04). The median time of follow-up after allo-HSCT was 45 months (ranging from 3 to 92). The mortality was 10% (2/20) in the frontline haplo-HSCT group, and 42.1% (8/19) in the salvage haplo-HSCT group. The estimated 5-year failure-free survival rate (FFS) of the frontline haplo-HSCT group was higher than that of the salvage haplo-HSCT group (90% vs 57.4%) (P=0.02). CONCLUSION: The frontline haplo-HSCT is an effective and safe approach for the patients with severe aplastic anemia who lack a HLA-matched sibling donor.

[Correlation between Plasma microRNA Expression and Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To investigate the microRNA (miRNA) expression in plasma of patients with aGVHD and without aGVHD after allo-hematopoietic stem cell transplantation (allo-HSCT). METHODS: The miRNAs (miR-423, mirR199a-3p, miR93*, miR377) expression levels in peripheral blood plasma of 25 patients before and after allo-HSCT were detected by real-time PCR. RESULTS: miR-423, miR199a-3p and miR-93* in aGVHD group were significantly upregulated (P<0.05); miR-377 expression was not significantly different between aGVHD and non-aGVHD (P>0.05). CONCLUSION: The expression of miR-423, miR-199a-3p, miR-93* are upregulated in aGVHD group, which can be used as biomarkes to monitor and to diagnose aGVHD.