Loss of perinuclear theca ACTRT1 causes acrosome detachment and severe male subfertility in mice.

The perinuclear theca (PT) is a cytoskeletal element encapsulating the sperm nucleus; however, the physiological roles of the PT in sperm are largely uncertain. Here, we reveal that ACTRT1, ACTRT2, ACTL7A and ACTL9 proteins interact to form a multimeric complex and localize to the subacrosomal region of spermatids. Furthermore, we engineered Actrt1-knockout (KO) mice to define the functions of ACTRT1. Despite normal sperm count and motility, Actrt1-KO males were severely subfertile owing to a deficiency in fertilization. Loss of ACTRT1 caused a high incidence of malformed heads and detachment of acrosomes from sperm nuclei, caused by loosened acroplaxome structure during spermiogenesis. Furthermore, Actrt1-KO sperm showed reduced ACTL7A and PLCζ protein content as a potential cause of fertilization defects. Moreover, we reveal that ACTRT1 anchors developing acrosomes to the nucleus, likely by interacting with the inner acrosomal membrane protein SPACA1 and the nuclear envelope proteins PARP11 and SPATA46. Loss of ACTRT1 weakened the interaction between ACTL7A and SPACA1. Our study and recent findings of ACTL7A/ACTL9-deficient sperm together reveal that the sperm PT-specific ARP complex mediates the acrosome-nucleus connection.

Bone marrow macrophages are involved in the ineffective hematopoiesis of myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are a group of heterogeneous myeloid clonal disorders characterized by ineffective hematopoiesis. Accumulating evidence has shown that macrophages (MΦs) are important components in the regulation of tumor progression and hematopoietic stem cells (HSCs). However, the roles of bone marrow (BM) MΦs in regulating normal and malignant hematopoiesis in different clinical stages of MDS are largely unknown. Age-paired patients with lower-risk MDS (N = 15), higher-risk MDS (N = 15), de novo acute myeloid leukemia (AML) (N = 15), and healthy donors (HDs) (N = 15) were enrolled. Flow cytometry analysis showed increased pro-inflammatory monocyte subsets and a decreased classically activated (M1) MΦs/alternatively activated (M2) MΦs ratio in the BM of patients with higher-risk MDS compared to lower-risk MDS. BM MФs from patients with higher-risk MDS and AML showed impaired phagocytosis activity but increased migration compared with lower-risk MDS group. AML BM MΦs showed markedly higher S100A8/A9 levels than lower-risk MDS BM MΦs. More importantly, coculture experiments suggested that the HSC supporting abilities of BM MΦs from patients with higher-risk MDS decreased, whereas the malignant cell supporting abilities increased compared with lower-risk MDS. Gene Ontology enrichment comparing BM MΦs from lower-risk MDS and higher-risk MDS for genes was involved in hematopoiesis- and immunity-related pathways. Our results suggest that BM MΦs are involved in ineffective hematopoiesis in patients with MDS, which indicates that repairing aberrant BM MΦs may represent a promising therapeutic approach for patients with MDS.

Mini-dose methotrexate combined with methylprednisolone for the initial treatment of acute GVHD: a multicentre, randomized trial.

BACKGROUND: There is an urgent unmet need for effective initial treatment for acute graft-versus-host disease (aGVHD) adding to the standard first-line therapy with corticosteroids after allogeneic haematopoietic stem cell transplantation (allo-HSCT). METHODS: We performed a multicentre, open-label, randomized, phase 3 study. Eligible patients (aged 15 years or older, had received allo-HSCT for a haematological malignancy, developed aGVHD, and received no previous therapies for aGVHD) were randomly assigned (1:1) to receive either 5 mg/m2 MTX on Days 1, 3, or 8 and then combined with corticosteroids or corticosteroids alone weekly. RESULTS: The primary endpoint was the overall response rate (ORR) on Day 10. A total of 157 patients were randomly assigned to receive either MTX plus corticosteroids (n = 78; MTX group) or corticosteroids alone (n = 79; control group). The Day 10 ORR was 97% for the MTX group and 81% for the control group (p = .005). Among patients with mild aGVHD, the Day 10 ORR was 100% for the MTX group and 86% for the control group (p = .001). The 1-year estimated failure-free survival was 69% for the MTX group and 41% for the control group (p = .002). There were no differences in treatment-related adverse events between the two groups. CONCLUSIONS: In conclusion, mini-dose MTX combined with corticosteroids can significantly improve the ORR in patients with aGVHD and is well tolerated, although it did not achieve the prespecified 20% improvement with the addition of MTX. TRIAL REGISTRATION: The trial was registered with clinicaltrials.gov (NCT04960644).

Prediction model for EBV infection following HLA haploidentical matched hematopoietic stem cell transplantation.

AIMS: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective treatment for hematological malignancies. However, viral infections, particularly EBV infection, frequently occur following allo-HSCT and can result in multi-tissue and organ damage. Due to the lack of effective antiviral drugs, these infections can even progress to post-transplant lymphoproliferative disorders (PTLD), thereby impacting the prognosis. In light of this, our objective is to develop a prediction model for EBV infection following allo-HSCT. METHODS: A total of 466 patients who underwent haploidentical hematopoietic stem cell transplantation (haplo-HSCT) between September 2019 and December 2020 were included in this study. The patients were divided into a development cohort and a validation cohort based on the timing of their transplantation. Our aim was to develop and validate a grading scale using these cohorts to predict the risk of EBV infection within the first year after haplo-HSCT. Additionally, single-cell RNA sequencing (sc-RNAseq) data from the bone marrow of healthy donors were utilized to assess the impact of age on immune cells and viral infection. RESULTS: In the multivariate logistic regression model, four predictors were retained: donor age, female-to-male transplant, graft MNC (mononuclear cell) dose, and CD8 dose. Based on these predictors, an EBV reactivation predicting score system was constructed. The scoring system demonstrated good calibration in both the derivation and validation cohorts, as confirmed by the Hosmer-Lemeshow test (p > 0.05). The scoring system also exhibited favorable discriminative ability, as indicated by the C statistics of 0.72 in the derivation cohort and 0.60 in the validation cohort. Furthermore, the clinical efficacy of the scoring system was evaluated using Kaplan-Meier curves based on risk ratings. The results showed significant differences in EBV reactivation rates between different risk groups, with p-values less than 0.001 in both the derivation and validation cohorts, indicating robust clinical utility. The analysis of sc-RNAseq data from the bone marrow of healthy donors revealed that older age had a profound impact on the quantity and quality of immune subsets. Functional enrichment analysis highlighted that older age was associated with a higher risk of infection. Specifically, CD8 + T cells from older individuals showed enrichment in the pathway of "viral carcinogenesis", while older CD14 + monocytes exhibited enrichment in the pathway of "regulation of viral entry into host cell." These findings suggest that older age may contribute to an increased susceptibility to viral infections, as evidenced by the altered immune profiles observed in the sc-RNAseq data. CONCLUSION: Overall, these results demonstrate the development and validation of an effective scoring system for predicting EBV reactivation after haplo-HSCT, and provide insights into the impact of age on immune subsets and viral infection susceptibility based on sc-RNAseq analysis of healthy donors' bone marrow.

All-trans retinoic acid plus low-dose rituximab vs low-dose rituximab in corticosteroid-resistant or relapsed ITP.

The study aimed to compare the efficacy and safety of all-trans retinoic acid (ATRA) plus low-dose rituximab (LD-RTX) with LD-RTX monotherapy in corticosteroid-resistant or relapsed immune thrombocytopenia (ITP) patients. Recruited patients were randomized at a ratio of 2:1 into 2 groups: 112 patients received LD-RTX plus ATRA, and 56 patients received LD-RTX monotherapy. Overall response (OR), defined as achieving a platelet count of ≥30 × 109/L confirmed on ≥2 separate occasions (≥7 days apart), at least a doubling of the baseline platelet count without any other ITP-specific treatment, and the absence of bleeding within 1 year after enrollment, was observed in more patients in the LD-RTX plus ATRA group (80%) than in the LD-RTX monotherapy group (59%) (between-group difference, 0.22; 95% CI, 0.07-0.36). Sustained response (SR), defined as maintenance of a platelet count >30 × 109/L, an absence of bleeding, and no requirement for any other ITP-specific treatment for 6 consecutive months after achievement of OR during 1 year following enrollment, was achieved by 68 (61%) patients in the combination group and 23 (41%) patients in the monotherapy group (between-group difference, 0.20; 95% CI, 0.04-0.35). The 2 most common adverse events (AEs) for the combination group were dry skin and headache or dizziness. Our findings demonstrated that ATRA plus LD-RTX significantly increased the overall and sustained response, indicating a promising treatment option for corticosteroid-resistant or relapsed adult ITP. This study is registered at www.clinicaltrials.gov as #NCT03304288.

Targeting TFH cells is a novel approach for donor-specific antibody desensitization of allograft candidates: an in vitro and in vivo study.

The presence of donor-specific antibodies (DSA) are associated with graft failure either following human leukocyte antigen (HLA)-mismatched allogeneic stem cell transplantation or after organ transplantation. Although targeting B cells and plasma cells have been used for desensitization, there have been reports of failure. T-follicular helper (Tfh) cells assist B cells in differentiating into antibody-secreting plasma cells. We used haploidentical allograft as a platform to investigate the possibility of targeting Tfh cells to desensitize DSA. The quantities of circulating Tfh (cTfh) cell subsets in allograft candidates were abnormal, and these cells, including the cTfh2 and cTfhem cell subsets, were positively related to the production of anti-HLA antibodies. Ex vivo experiments showed that the cTfh cells of anti-HLA antibody-positive allograft candidates could induce B cells to differentiate into DSA-producing plasmablasts. The immune synapse could be involved in the assistance of cTfh cells to B cells in antibody production. In vitro experiments and in vivo clinical pilot studies indicated that targeting cTfh cells with sirolimus can inhibit their auxiliary function in assisting B cells. Ex vivo and in vivo studies demonstrated the effect of sirolimus and rituximab on DSA desensitization compared with either sirolimus or rituximab alone (60%, 43.75%, and 30%, respectively). Our findings provide new insight into the role of Tfh cells in the pathogenesis of DSA production in HLA-mismatched transplant candidates. Our data also indicate that targeting Tfh cells is a novel strategy for DSA desensitization and combination of sirolimus and rituximab might be a potential therapy. The prospective cohort of this study is registered at http://www.chictr.org.cn as #ChiCTR-OPC-15006672.

Clinical characteristics and prognosis of acute myeloid leukemia patients with Runt-related transcription factor 1 mutation: A single-center retrospective analysis.

This study aimed to investigate the clinical characteristics and prognosis of Runt-related transcription factor 1 (RUNX1) mutant acute myeloid leukemia (AML) patients by comparing the features of AML patients with or without RUNX1 mutation. We retrospectively analyzed 180 AML patients including 36 AML patients with mutant RUNX1(AML-RUNX1mut ) and 144 AML patients with wild-type RUNX1(AML-RUNX1wt ) were selected using the case-pair method(1:4). Compared to AML-RUNX1wt , AML-RUNX1mut showed higher frequency of ASXL1 (p < 0.001), SRSF2 (p < 0.001), BCORL1 (p < 0.001), RAS (p = 0.010) mutations, and absent NPM1 mutations (p = 0.022). The 3-year overall survival (OS) and disease-free survival (DFS) of AML-RUNX1mut and AML-RUNX1wt were 73.1% versus 68.0% (p = 0.64) and 80.7% versus 71.6% (p = 0.37), respectively. AML-RUNX1mut receiving allogeneic hematopoietic cell transplantation (allo-HSCT) showed better survival than those who did not receive allo-HSCT (3-year OS, 84.3% vs. 52.7%; p = 0.006). Multivariate analysis showed that EZH2 mutation (p = 0.003), white blood cell (WBC) ≥30 × 109 /L (p = 0.036) and age ≥60 years (p = 0.038) were significant independent risk factors for inferior OS of AML-RUNX1mut ; WBC ≥30 × 109 /L (p = 0.013) and DNMT3A mutation (p = 0.045) were significant independent risk factors for shorter DFS of AML-RUNX1mut . In conclusion, AML-RUNX1mut showed unique clinical characteristics, but the survival between AML-RUNX1mut and AML-RUNX1wt were comparable. EZH2 co-mutation, DNMT3A co-mutation, old age and high WBC count were associated with inferior survival of AML-RUNX1mut . Allo-HSCT can significantly improve the prognosis of AML-RUNX1mut .

A predictive model of herpes zoster after allogeneic hematopoietic stem cell transplantation: VZV reactivation following antiviral prophylaxis discontinuation.

Herpes zoster (HZ) refers to the rash appearing on dermatomes due to varicella zoster virus (VZV) reactivation. The incidence of HZ is significantly higher in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients than in non-HSCT recipients. Although acyclovir prophylaxis is routinely administered to every allo-HSCT recipient for 1 year after transplantation, some individuals eventually develop late-onset HZ after completing prophylaxis. Little information is known about the clinical features of HZ after prophylactic antiviral treatment discontinuation, and an effective predictive model of late-onset HZ needs to be established. A total of 3366 patients who had received allo-HSCT from 2012 to 2017 were included in our study, among whom 201 developed HZ after 1 year (late-onset HZ). We designed a nested case-control study to identify potential predictors of late-onset HZ. Finally, we established a predictive model using binary logistic regression analysis. Age (p < .001), use of immunosuppressants at +1 year (p < .001), CD4-CD8 ratio at +1 year (p < .001), certain mental disorders (depression, anxiety, insomnia and adjustment disorder) (p < .001), engraftment time of neutrophils (p < .001), and CD8+ cell count at +30 days (p < .001) were independent predictors of late-onset HZ. A risk grading system was established based on regression coefficients. Discrimination and calibration analysis indicated that the model had good performance. We also identified several predictive factors of the incidence of HZ-related complications. This is the first scoring system for predicting the incidence of late-onset HZ after allo-HSCT. This model can be applied to identify individuals at high risk of late-onset HZ in the early period after receiving allo-HSCT.

The prognosis of haploidentical hematopoietic stem cell transplantation in infants and patients under 3 years old with acute leukemia.

BACKGROUND: The role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients <3 years of age remains controversial. Data on haploidentical donor (HID) transplants in this age group is limited. PATIENTS AND METHODS: We retrospectively analyzed the prognosis of 97 patients with acute leukemia aged <3 years who underwent HID transplantation at our institute. RESULTS: With a median follow-up of 45 months, the 3-year disease-free survival (DFS), overall survival (OS), and 3-year cumulative incidence rate of treatment-related mortality were 69.3% (95% confidence interval (CI): 59.9%-78.7%), 74.2% (95% CI: 65.2%-83.2%), and 3.6% (95% CI: 0.9%-9.7%) in all 97 patients, respectively. The 3-year DFS and OS rate in patients diagnosed <1 year and patients diagnosed ≥1 year were comparable: 77.8% (95% CI: 62.2%-93.4%) versus 66.3% (95% CI: 55.0%-77.6%, p = .253) and 82.5% (95% CI: 66.3-98.7%) versus 72.8% (95% CI: 61.9%-83.7%, p = .153), respectively. At the last follow-up, 23 patients had died, and 20 had died of relapse. Multivariate analysis revealed that positive pre-HSCT flow cytometric minimal residual disease (hazard ratio 5.605, p = .000) and AML-M7 expression (hazard ratio 2.906, p = .014) were independent adverse prognostic variables for relapse. CONCLUSIONS: HID transplantation is potent and safe for infants and young patients with acute leukemia. Relapse is the primary cause of treatment failure.

Cytology or Multiparameter Flow Cytometry Positivity in the Cerebrospinal Fluid Before Transplantation is Predictive of Poor Outcomes After Allotransplantation in Acute Myeloid Leukemia Patients.

INTRODUCTION: Central nervous system leukemia (CNSL) remains a serious complication in patients with acute myeloid leukemia (AML) and an ambiguous prognostic factor for those receiving allo-geneic hematopoiesis stem cell transplantation (allo-HSCT). It is unknown whether using more sensitive tools, such as multiparameter flow cytometry (MFC), to detect blasts in the cerebrospinal fluid (CSF) would have an impact on outcome. METHODS: We retrospectively analyzed the clinical outcomes of 1472 AML patients with or without cytology or MFC positivity in the CSF before transplantation. Abnormal CSF (CSF+) was detected via conventional cytology and MFC in 44 patients at any time after diagnosis. A control group of 175 CSF-normal (CSF-) patients was generated via propensity score matching (PSM) analyses according to sex, age at transplant, and white blood cell count at diagnosis. RESULTS: Compared to those in the CSF-negative group, the conventional cytology positive and MFC+ groups had comparable 8-year nonrelapse mortality (NRM) (4%, 4%, and 6%, p = 0.82), higher cumulative incidence of relapse (CIR) (14%, 31%, and 32%, p = 0.007), lower leukemia-free survival (LFS) (79%, 63%, and 64%, p = 0.024), and overall survival (OS) (83%, 63%, and 68%, p = 0.021), with no significant differences between the conventional cytology positive and MFC+ groups. Furthermore, multivariate analysis confirmed that CSF involvement was an independent factor affecting OS and LFS. CONCLUSION: Our results indicate that pretransplant CSF abnormalities are adverse factors independently affecting OS and LFS after allotransplantation in AML patients.

Functional Competence of NK Cells via the KIR/MHC Class I Interaction Correlates with DNAM-1 Expression.

The interaction of inhibitory receptors with self-MHC class I (MHC-I) molecules is responsible for NK cell education. The intensity of DNAM-1 expression correlates with NK cell education. However, whether DNAM-1 expression directly influences the functional competence of NK cells via the KIR/MHC-I interaction remains unclear. Based on allogeneic haploidentical hematopoietic stem cell transplantation, we investigated the intensity of DNAM-1 expression on reconstituted NK cells via the interaction of KIR with both donor HLA and recipient HLA at days 30, 90, and 180 after hematopoietic stem cell transplantation. The reconstituted NK cells educated by donor and recipient HLA molecules showed the highest DNAM-1 expression, whereas DNAM-1 expression on educated NK cells with only recipient HLA molecules was higher than that on educated NK cells with only donor HLA molecules, indicating that NK cells with donor or recipient HLA molecules regulate DNAM-1 expression and thereby affect NK cell education. Additionally, the effects of recipient cells on NK cell education were greater than those of donor cells. However, only when the DNAM-1, NKP30, and NKG2D receptors were blocked simultaneously was the function of educated and uneducated NK cells similar. Therefore, activating receptors may collaborate with DNAM-1 to induce educated NK cell hyperresponsiveness. Our data, based on in vitro and in vivo studies, demonstrate that the functional competence of NK cells via the KIR/MHC-I interaction correlates with DNAM-1 expression in human NK cells.

Outcome and prognostic factors of haploidentical allogeneic hematopoietic stem cell transplantation in pediatric relapsed or refractory ETV6/RUNX1-positive acute lymphoblastic leukemia.

INTRODUCTION: the role of haploidentical allogeneic hematopoietic stem cell transplantation (haplo-HSCT) in pediatric patients with relapsed or refractory (R/R) ETV6/RUNX1-positive acute lymphoblastic leukemia (ALL) is unclear. This study aimed to identify prognostic factors and explore the role of haplo-HSCT in the treatment of ETV6/RUNX1-positive ALL. METHODS: we analyzed the clinical characteristics and treatment outcomes of 20 pediatric patients who were diagnosed with ETV6/RUNX1-positive ALL and received chemotherapy/chimeric antigen receptor T-cell bridged to haplo-HSCT between 2016 and 2021 at our institution. RESULTS: with a median follow-up time of 47 months, the 3-year cumulative incidence of relapse, disease-free survival, and overall survival were 35.9% (95% confidence interval (CI): 15.3-57.1%), 59.1% (95% CI: 37.2-81.0%), and 75.0% (95% CI: 56.0-94.0%), respectively. Multivariate analysis revealed that pre-HSCT measurable residual disease (MRD) positivity (hazard ratio, 13.275; 95% CI: 2.406-73.243; P = 0.003) had a significant negative impact on relapse. A total of 7 patients experienced positive ETV6/RUNX1 gene expression at a median of 7.2 months after haplo-HSCT, 5 of them experienced relapse at a median time of 12.1 months after haplo-HSCT. ROC curve analysis was performed to analyze the significance of pre-HSCT and post-HSCT ETV6/RUNX1 transcripts for predicting relapse; the AUC were 0.798 (95% CI: 0.567-1.0, P=0.035) and 0.875 (95% CI: 0.690-1.0, P=0.008), respectively. The optimal cut-off points to predict an inevitable relapse were 0.011% and 0.0019%, respectively. CONCLUSION: patients with R/R ETV6/RUNX1-positive ALL may benefit from haplo-HSCT. Deeply eliminating pre-HSCT MRD and preemptive treatment for post-HSCT MRD may be crucial to further improving the prognosis.

Haploidentical hematopoietic stem cell transplantation with busulfan, cyclophosphamide, and fludarabine conditioning for X-linked adrenal cerebral leukodystrophy.

OBJECTIVE: We investigated the safety and efficacy of haploidentical stem cell transplantation (SCT) in pediatric patients with X-linked adrenoleukodystrophy (ALD). METHODS: A retrospective analysis of transplantation data from 29 cases of ALD, treated between December 2014 and April 2022, was conducted. Neurologic function scores (NFS) were assessed. The conditioning regimen was busulfan 9.6 mg/kg, cyclophosphamide 200 mg/kg, and fludarabine 90 mg/m2 (BFC). Graft-versus-host disease prophylaxis consisted of anti-human thymocyte globulin, cyclosporine A, mycophenolate mofetil, and short course of methotrexate. RESULTS: Among the 29 cases, 14 cases (NFS = 0) were asymptomatic, and 15 (NFS ≥ 1) were symptomatic. The median age at SCT was 8 years (range: 4-16 years); the median follow-up time was 1058 days (range: 398-3092 days); 28 cases were father donors and 1 case was a grandfather donor. Hematopoietic reconstitution was successful in all patients, and all of them achieved complete donor chimerism at the time of engraftment. The leading cause of death was still primary disease progression (n = 4). Survival free of major functional disabilities was 100% in asymptomatic patients versus 66.67% in the symptomatic group (p = .018). CONCLUSION: BFC regimen used in haploidentical SCT was administered safely without major transplant-related complications even in symptomatic patients, and neurological symptoms were stabilized after SCT.

CAR-T Therapy Followed by Hematopoietic Stem Cell Transplantation Can Improve Survival in Children Relapsed/Refractory Philadelphia Chromosome-positive B-cell Acute Lymphoblastic Leukemia.

BACKGROUND: Philadelphia chromosome (Ph)-positive B-cell acute lymphoblastic leukemia (ALL) has a high complete remission (CR) rate, but relapse and prolonged measurable residual disease remain serious problems. We sought to describe the CR rate measurable residual disease negative rate and address the results and safety of pediatric patients who underwent after receiving chimeric antigen receptor (CAR) specific for CD19 (CAR-19) followed by hematopoietic stem cell transplantation (HSCT) for the treatment of Ph-positive ALL. METHODS: A descriptive study was conducted at Peking University People's Hospital from September 2013 to January 2021. 13 patients with relapsed/refractory Ph-positive B-ALL who received CAR-T therapy followed by allo-HSCT were included. We concentrated on the overall patient survival and CR rate. RESULTS: The median time between CAR-T therapy and allo-HSCT was 58 days. Among all the patients, the CR rate was 100%, the flow cytometry negativity rate was 84.62%, and the BCR-ABL negativity rate was 53.85% at 1 month after CAR-T infusion. All the patients achieved a major molecular response in 6 months after HSCT. After a median follow-up of 45 months, the 3-year OS rate was 66.7%, and the 3-year DFS rate was 61.5%. The 3-year OS rate of patients with BCR-ABL-positive pre-HSCT was significantly lower than that in the BCR-ABL-negative group (40.0% vs. 85.7%, P =0.042). Also, the same trend was observed for the 3-year DFS rate but did not differ significantly (40.0% vs. 75.0%, P =0.233). CONCLUSIONS: CAR-T therapy followed by allo-HSCT can be a safe and effective treatment for Ph-positive B-ALL pediatric patients.

Tacrolimus prevents complement-mediated Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation and pyroptosis of mesenchymal stem cells from immune thrombocytopenia.

The abnormal immunomodulatory functions of mesenchymal stem cells (MSCs) have been implicated in the development of immune thrombocytopenia (ITP). Recent studies have suggested important effects of complement on immune cell function. However, whether complement modulates bone marrow MSCs function in ITP is poorly defined. Tacrolimus has recently been applied to the treatment of autoimmune diseases. Here, we explored whether impaired ITP-MSCs could be targeted by tacrolimus. Our results showed that the Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome was activated in ITP MSCs with complement deposition (MSCs-C+ ) and initiated caspase-1-dependent pyroptosis. Transcriptome sequencing results showed abnormal fatty acid metabolism in MSCs-C+ . Enhanced fatty acid ß-oxidation and reactive oxygen species production activated the NLRP3 inflammasome. Adipocytes derived from MSCs-C+ secreted less adiponectin. Adiponectin promoted the differentiation of megakaryocytes and inhibited the destruction of platelets. Tacrolimus inhibited NLRP3 inflammasome activation and MSCs-C+ pyroptosis in vitro and in vivo. Tacrolimus plus danazol elicited a higher sustained response than danazol monotherapy in corticosteroid-resistant patients with ITP. Our findings demonstrate that the activation of the NLRP3 inflammasome in ITP MSCs mediated by complement could be inhibited by tacrolimus, which might be a potential new therapy for ITP.

The nuclear factor erythroid 2-related factor 2 agonist tert-butylhydroquinone improves bone marrow mesenchymal stromal cell function in prolonged isolated thrombocytopenia after allogeneic haematopoietic stem cell transplantation.

Prolonged isolated thrombocytopenia (PT) is a life-threatening comorbidity associated with allogeneic haematopoietic stem cell transplantation (allo-HSCT). Our previous study indicated that dysfunctional bone marrow mesenchymal stromal cells (BM MSCs) played a role in PT pathogenesis and that reactive oxygen species (ROS) accumulation was related to BM MSC senescence and apoptosis. However, the mechanism of the increase in ROS levels in the BM MSCs of PT patients is unknown. In the current case-control study, we investigated whether nuclear factor erythroid 2-related factor 2 (NRF2), which is a central regulator of the cellular anti-oxidant response that can clear ROS in human BM MSCs, was associated with PT after allo-HSCT. We evaluated whether an NRF2 agonist (tert-butylhydroquinone, TBHQ) could enhance BM MSCs from PT patients in vitro. We found that BM MSCs from PT patients exhibited increased ROS levels and reduced NRF2 expression. Multivariate analysis showed that low NRF2 expression was an independent risk factor for primary PT [p = 0.032, Odds ratio (OR) 0.868, 95% confidence interval (CI) 0.764-0.988]. In-vitro treatment with TBHQ improved the quantity and function of BM MSCs from PT patients by downregulating ROS levels and rescued the impaired BM MSC support of megakaryocytopoiesis. In conclusion, these results suggested that NRF2 downregulation in human BM MSCs might be involved in the pathogenesis of PT after allo-HSCT and that BM MSC impairment could be improved by NRF2 agonist in vitro. Although further validation is needed, our data indicate that NRF2 agonists might be a potential therapeutic approach for PT patients after allo-HSCT.

Outcomes of haploidentical haematopoietic stem cell transplantation for adolescent and young adults with acute myeloid leukaemia.

We aimed to identify the efficacy of haploidentical related donor (HID) haematopoietic stem cell transplantation (HSCT) in adolescent and young adults (AYAs) with acute myeloid leukaemia (AML) in a large cohort. Consecutive AML AYAs (15-39 years old, n = 599) receiving HID HSCT in complete remission (CR) were included. The 3-year cumulative incidence of measurable residual disease occurrence, relapse and non-relapse mortality after HID HSCT was 28.6% (95% CI: 25.0-32.2), 11.6% (95% CI: 9.0-14.2) and 6.7% (95% CI: 4.7-8.7) respectively. The 3-year probability of event-free survival, leukaemia-free survival (LFS) and overall survival (OS) after HID HSCT was 60.7% (95% CI: 56.9-64.8), 81.7% (95% CI: 78.7-84.9) and 85.6% (95% CI: 82.8-88.4) respectively. In multivariable analysis, AML risk category at diagnosis and comorbidity burdens before HID HSCT were independently associated with LFS and OS. Compared to the older adults (≥ 40 years, n = 355) with AML receiving HID HSCT in CR during the same time period, AYAs have a lower incidence of non-relapse mortality and higher probabilities of LFS and OS. Thus, we firstly confirmed the safety and efficacy of HID HSCT in AYAs with AML-CR.

Predicting short-term and long-term mortalities from sepsis in patients who receive allogeneic haematopoietic stem cell transplantation.

Patients who receive allogeneic haematopoietic stem cell transplantation (allo-HSCT) may develop sepsis, which result in a highly intensive care unit admission rate and mortality. Therefore, short-term and long-term prognostic models for sepsis after allo-HSCT are urgently needed. We enrolled patients receiving allo-HSCT who developed sepsis after allo-HSCT at Peking University People's Hospital between 2012 and 2021, including 287 patients who received allo-HSCT in 2018-2021 in the derivation cohort, and 337 patients in 2012-2017 in the validation cohort. Multivariate logistic regression analysis was used to identify prognostic factors, and these identified factors were incorporated into two scoring models. Seven independent factors (acute graft-versus-host disease (GVHD), chronic GVHD (cGVHD), total bilirubin, lactate dehydrogenase (LDH) and organ dysfunction [renal, lung and heart]) were included in the 6-month prognostic model, and six factors (cGVHD, C-reactive protein, LDH, organ dysfunction [lung, neurologic and coagulation]) were included in the 14-day prognostic model. The area under the receiver operating characteristic curves, calibration plots and decision curve analysis demonstrated the robust predictive performance of the models, better than the Sequential Organ Failure Assessment score. Early identification of patients with high risk of 6-month and 14-day death may allow clinicians to provide timely treatments and improve the therapeutic effects.

Comparison of outcomes for patients with acute myeloid leukemia undergoing haploidentical stem cell transplantation in first and second complete remission.

There was no consensus on whether prognostic advantages existed when transplant conducted at first complete remission (CR1) stage than at second complete remission (CR2) stage for patients with AML who received haploidentical hematological stem cell transplantation (haplo-HSCT). In 768 consecutive AML patients who received haplo-HSCT from January 2014 to December 2017, a 1:2 ratio matched-pair analysis was performed, 69 patients who in CR2 group and 138 CR1 patients were enrolled. Hematopoietic recovery, graft versus host disease (GVHD), relapse, transplant related mortality (TRM), disease-free survival (DFS) and overall survival (OS) were compared in two groups, and further evaluated in low-, intermediate-, and high-risk subgroups. The cumulative incidences of 30-day myeloid recovery and 90-day platelet recovery were comparable in CR1 and CR2 groups. The cumulative incidences of grade II-IV and grade III-IV aGVHD were not significantly different. The cumulative incidences of relapse at 3-year and 5-year in these two groups were 12.4% versus 11.6% (P = 0.880) and 12.4% versus 17.5% (P = 0.322). The cumulative incidences of TRM at 3-year and 5-year were both 10.9% versus 23.2% (P = 0.019). The probability of DFS at 3-year and 5-year were 76.7% versus 65.2% (P = 0.029) and 76.7% versus 59.3% (P = 0.009). The probability of OS at 3-year and 5-year were 81.8% versus 68.1% (P = 0.026) and 76.7% versus 59.3% (P = 0.026). In the intermediate-risk group, TRM was lower in CR1 group, DFS and OS of CR1 group were superior to CR2 group. In conclusion, haplo-HSCT at CR1 stage was of better prognosis for intermediate-risk AML patients than at CR2 stage.

Improved Vδ2+ T cells recovery correlates to reduced incidences of mortality and relapse in acute myeloid leukemia after hematopoietic transplantation.

Acute myeloid leukemia (AML) patients can benefit from allogeneic hematopoietic cell transplantation (alloHCT) and achieve long-term remission. Recovery of T cell quantity and quality is critical to reduce the incidences of life-threatening complications after alloHCT. Although the general recovery level of γδ T cells is recognized to be associated with outcomes of patients who suffered from various hematological diseases and received alloHCT, the correlation between γδ T cell subsets and the prognosis in AML patients following transplantation remains to be investigated. In the current study, the recoveries of T cell subpopulations in 103 AML patients were dissected at different time points after haploidentical HCT (haploHCT). Statistical analyses showed that the absolute number of Vδ2+ T cells on day 90 was an independent risk factor for predicting 2-year OS in AML patients following haploHCT. The survival advantage from the improved recovery of day-90 Vδ2+ T cells was attributed to reducing the infection-related mortality. Consistently, lower 2-year non-relapse mortality was found in recipients with higher day-90 levels of Vδ2+ T cells. Notably, day-270 Vδ2+ T cell numbers reversely correlated to both 2-year and 5-year probabilities of relapse in this scenario. These results highlighted the significant correlation of Vδ2+ T cells recovery with long-term survival and relapse after alloHCT, suggesting that Vδ2+ T cells-based immune strategies may help control infectious complications and leukemia recurrence in AML patients.