血液科学(英文)最新文献

Rituximab maintenance (RM) prolongs the progression-free survival (PFS) of responding patients with follicular lymphoma (FL), but the maintenance efficacy in different Follicular Lymphoma International Prognostic Index (FLIPI) risk group is still confusing. We performed a retrospective analysis of the effect of RM treatments in patients with FL responding to induction therapy based on their FLIPI risk assessment carried out prior to treatment. We identified 93 patients between 2013 and 2019 who received RM every 3 months for ≥4 doses (RM group), and 60 patients who did not accept RM or received rituximab less than 4 doses (control group). After a median follow-up of 39 months, neither median overall survival (OS) nor PFS was reached for the entire population. The PFS was significantly prolonged in the RM group compared to the control group (median PFS NA vs 83.1 months, P = .00027). When the population was divided into the 3 FLIPI risk groups, the PFS differed significantly (4-year PFS rates, 97.5% vs 88.8% vs 72.3%, P = .01) according to group. There was no significant difference in PFS for FLIPI low-risk patients with RM compared to the control group (4-year PFS rates, 100% vs 93.8%, P = .23). However, the PFS of the RM group was significantly prolonged for FLIPI intermediate-risk (4-year PFS rates, 100% vs 70.3%, P = .00077) and high-risk patients (4-year PFS rates, 86.7% vs 57.1%, P = .023). These data suggest that standard RM significantly prolongs the PFS of patients assigned to intermediate- and high-risk FLIPI groups but not to low-risk FLIPI group, and pending larger-scale studies to validate.

Leukemia stem cells in acute myeloid leukemia (AML) can persist within unique bone marrow niches similar to those of healthy hematopoietic stem cells and resist chemotherapy. In the context of AML, endothelial cells (ECs) are crucial components of these niches that appear to promote malignant expansion despite treatment. To better understand these interactions, we developed a real-time cell cycle-tracking mouse model of AML (Fucci-MA9) with an aim of unraveling why quiescent leukemia cells are more resistant to chemotherapy than cycling cells and proliferate during disease relapse. We found that quiescent leukemia cells were more prone to escape chemotherapy than cycling cells, leading to relapse and proliferation. Importantly, post-chemotherapy resting leukemia cells tended to localize closer to blood vessels. Mechanistically, after chemotherapy, resting leukemia cells interacted with ECs, promoting their adhesion and anti-apoptotic capacity. Further, expression analysis of ECs and leukemia cells during AML, after chemotherapy, and after relapse revealed the potential of suppressing the post-chemotherapy inflammatory response to regulate the functions of leukemia cells and ECs. These findings highlight the role of leukemia cells in evading chemotherapy by seeking refuge near blood vessels and provide important insights and directions for future AML research and treatment.

Hemochromatosis, either hereditary hemochromatosis (HH) or secondary hemochromatosis, consists of the accumulation of iron in the liver, heart, and other organs. It leads to end-organ damage in a proportion of affected subjects. Although liver-related morbidity (cirrhosis and hepatocellular carcinoma [HCC]) and mortality are well established, the frequency of these complications remains controversial. The aim of this study is to examine the rate of hospitalization and the incidence of iron overload-related comorbidities in patients with hemochromatosis between the years of 2002 and 2010. We queried the Nationwide Inpatient Sample (NIS) database from the year 2002 to 2010. We included adults (age ≥18 years) and used the ICD-CM 9 code 275.0x to identify hospitalized patients with a diagnosis of hemochromatosis. Data analysis for this study was generated using SAS software version 9.4. A total of 168,614 hospitalized patients between 2002 and 2010 had a diagnosis of hemochromatosis. The majority were males (57%) with a median age of 54 years (37-68), with a predominance of white patients (63.3%) followed by black (26.8%). The rate of hospitalization among patients with hemochromatosis increased by 79% between the years 2002 and 2010 (34.5/100,000 in 2002 vs 61.4/100,000 in 2010). The main associated diagnoses were diabetes mellitus (20.2%), cardiac disease, including arrhythmias (14%) and cardiomyopathy (dilated 3.8%; peri-, endo-, myocarditis 1.3%), liver cirrhosis (8.6%), HCC (1.6%), and acute liver failure (0.81%). Of note, HCC was associated with cirrhosis in 1188 patients (43% of HCC patients) and male sex (87%). Diagnostic biopsies were performed in 6023 (3.6%) of those patients and liver transplant was performed in 881 (0.5%). In-hospital mortality occurred in 3638 (2.16%) patients. In this large database study, we found a rising trend in hospitalization for hemochromatosis, possibly due to the increased recognition of this entity and billing for the condition. The incidence of cirrhosis in hemochromatosis was found to be similar to other studies (8.6% vs 9%). However, the rate of HCC was lower than previous reports (1.6% vs 2.2%-14.9%), and only 43% of HCC was associated with cirrhosis. This raises important pathophysiologic questions regarding the impact of iron overload in HCC. There has been an increase in the rate of hospitalization for patients with a diagnosis of hemochromatosis. This may be related to an increased recognition of hemochromatosis as the underlying etiology for conditions such as diabetes, cardiomyopathy, cirrhosis, and HCC. Further prospective studies are needed to clarify the burden of liver disease in HH and secondary iron overload.

Although complete remission could be achieved in about 60%-70% of acute myeloid leukemia (AML) patients after conventional chemotherapy, relapse and the state of being refractory to treatment remain the main cause of death. In addition, there is a great need for less intensive regimens for all medically frail patients (both due to age/comorbidity and treatment-related). Immune therapy anticipates improved prognosis and reduced toxicities, which may offer novel therapeutic rationales. However, one of the major difficulties in developing immune therapies against AML is that the target antigens are also significantly expressed on healthy hematopoietic stem cells; B-cell malignancies are different because CD20/CD19/healthy B-cells are readily replaceable. Only the anti-CD33 antibody-drug conjugate gemtuzumab-ozogamicin is approved by the FDA for AML. Thus, drug development remains extremely active, although it is still in its infancy. This review summarizes the clinical results of immune therapeutic agents for AML, such as antibody-based drugs, chimeric antigen receptor therapy, checkpoint inhibitors, and vaccines.

Peripheral cisternae and double membranes (PCDMs) in erythroid cells are a landmark of type II congenital dyserythropoietic anemia (CDA). To gain further insights into the mechanism of dyserythropoiesis, erythroblasts and erythrocytes in bone marrow were studied in 22 Chinese patients with CDA Ⅱ by transmission electron microscopy. The study demonstrated an increase in all patients in erythroblasts with PCDMs with development from pro-erythroblast to red blood cells. PCDMs often connected with cisternae of endoplasmic reticulum (ER) and the perinuclear space, and were accompanied by karyopyknosis, karyolysis and disruption in polychromatic and orthochromatic erythroblasts. The results suggest that PCDMs are transformed from ER during erythropoiesis and participate in the dissolution and deletion of late erythroid cells in patients with CDA II.

Epstein-Barr virus (EBV) reactivation is one of the most important infections after hematopoietic stem cell transplantation (HSCT) using haplo-identical related donors (HID). We aimed to establish a comprehensive model with machine learning, which could predict EBV reactivation after HID HSCT with anti-thymocyte globulin (ATG) for graft-versus-host disease (GVHD) prophylaxis. We enrolled 470 consecutive acute leukemia patients, 60% of them (n = 282) randomly selected as a training cohort, the remaining 40% (n = 188) as a validation cohort. The equation was as follows: Probability (EBV reactivation) = $\frac{1}{1+exp(-Y)}$ , where Y = 0.0250 × (age) - 0.3614 × (gender) + 0.0668 × (underlying disease) - 0.6297 × (disease status before HSCT) - 0.0726 × (disease risk index) - 0.0118 × (hematopoietic cell transplantation-specific comorbidity index [HCT-CI] score) + 1.2037 × (human leukocyte antigen disparity) + 0.5347 × (EBV serostatus) + 0.1605 × (conditioning regimen) - 0.2270 × (donor/recipient gender matched) + 0.2304 × (donor/recipient relation) - 0.0170 × (mononuclear cell counts in graft) + 0.0395 × (CD34+ cell count in graft) - 2.4510. The threshold of probability was 0.4623, which separated patients into low- and high-risk groups. The 1-year cumulative incidence of EBV reactivation in the low- and high-risk groups was 11.0% versus 24.5% (P < .001), 10.7% versus 19.3% (P = .046), and 11.4% versus 31.6% (P = .001), respectively, in total, training and validation cohorts. The model could also predict relapse and survival after HID HSCT. We established a comprehensive model that could predict EBV reactivation in HID HSCT recipients using ATG for GVHD prophylaxis.

Tumor relapse is the major cause of treatment failure in childhood acute lymphoblastic leukemia (ALL), yet the underlying mechanisms are still elusive. Here, we demonstrate that phosphoribosyl pyrophosphate synthetase 2 (PRPS2) mutations drive ALL relapse through influencing PRPS1/2 hexamer stability. Ultra-deep sequencing was performed to identify PRPS2 mutations in ALL samples. The effects of PRPS2 mutations on cell survival, cell apoptosis, and drug resistance were evaluated. In vitro PRPS2 enzyme activity and ADP/GDP feedback inhibition of PRPS enzyme activity were assessed. Purine metabolites were analyzed by ultra-performance liquid-chromatography tandem mass spectrometry (UPLC-MS/MS). Integrating sequencing data with clinical information, we identified PRPS2 mutations only in relapsed childhood ALL with thiopurine therapy. Functional PRPS2 mutations mediated purine metabolism specifically on thiopurine treatment by influencing PRPS1/2 hexamer stability, leading to reduced nucleotide feedback inhibition of PRPS activity and enhanced thiopurine resistance. The 3-amino acid V103-G104-E105, the key difference between PRPS1 and PRPS2, insertion in PRPS2 caused severe steric clash to the interface of PRPS hexamer, leading to its low enzyme activity. In addition, we demonstrated that PRPS2 P173R increased thiopurine resistance in xenograft models. Our work describes a novel mechanism by which PRPS2 mutants drive childhood ALL relapse and highlights PRPS2 mutations as biomarkers for relapsed childhood ALL.

[This corrects the article DOI: 10.1097/BS9.0000000000000115.].