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.

Long-term follow-up of haploidentical haematopoietic stem cell transplantation in paediatric patients with high-risk acute myeloid leukaemia: Report from a single centre.

Data from 200 children with high-risk acute myeloid leukaemia who underwent their first haploidentical haematopoietic stem cell transplantation (haplo-HSCT) between 2015 and 2021 at our institution were analysed. The 4-year overall survival (OS), event-free survival (EFS) and cumulative incidence of relapse (CIR) were 71.9%, 62.3% and 32.4% respectively. The 100-day cumulative incidences of grade II-IV and III-IV acute graft-versus-host disease (aGVHD) were 41.1% and 9.5% respectively. The 4-year cumulative incidence of chronic GVHD (cGVHD) was 56.1%, and that of moderate-to-severe cGVHD was 27.3%. Minimal residual disease (MRD)-positive (MRD+) status pre-HSCT was significantly associated with lower survival and a higher risk of relapse. The 4-year OS, EFS and CIR differed significantly between patients with MRD+ pre-HSCT (n = 97; 63.4%, 51.4% and 41.0% respectively) and those with MRD-negative (MRD-) pre-HSCT (n = 103; 80.5%, 73.3% and 23.8% respectively). Multivariate analysis also revealed that acute megakaryoblastic leukaemia without Down syndrome (non-DS-AMKL) was associated with extremely poor outcomes (hazard ratios and 95% CIs for OS, EFS and CIR: 3.110 (1.430-6.763), 3.145 (1.628-6.074) and 3.250 (1.529-6.910) respectively; p-values were 0.004, 0.001 and 0.002 respectively). Thus, haplo-HSCT can be a therapy option for these patients, and MRD status pre-HSCT significantly affects the outcomes. As patients with non-DS-AMKL have extremely poor outcomes, even with haplo-HSCT, a combination of novel therapies is urgently needed.

Recent infection with SARS-CoV-2 in donors was associated with a higher incidence of acute graft-versus-host disease in recipients undergoing allogeneic haematopoietic stem cell transplantation.

The global pandemic has resulted in the common occurrence of SARS-CoV-2 infection in the population. In the post-pandemic era, it is imperative to understand the influence of donor SARS-CoV-2 infection on outcomes after allogeneic haematopoietic stem cell transplantation (allo-HSCT). We retrospectively analysed allo-HSCTs from donors with mild SARS-CoV-2 infection or early recovery stage (ERS) (group 1, n = 65) and late recovery stage (group 2, n = 120). Additionally, we included allo-HSCT from donors without prior SARS-CoV-2 infection as group 0 (n = 194). Transplants from donors with different SARS-CoV-2 infection status had comparable primary engraftment and survival rates. However, group 1 had higher incidences of acute graft-versus-host disease (aGvHD), grade II-IV (41.5% vs. 28.1% in group 0 [p = 0.014] and 30.6% in group 2 [p = 0.067]) and grade III-IV (22.2% vs. 9.6% [p = 0.004] in group 0 and 12.2% in group 2 [p = 0.049]). Conversely, the risk of aGvHD in group 2 was similar to that in group 0 (p > 0.5). Multivariable analysis identified group 1 associated with grade II-IV (hazard ratio [HR] 2.307, p = 0.010) and grade III-IV (HR 2.962, p = 0.001) aGvHD, which yielded no significant risk factors for survival. In conclusion, we preliminarily demonstrated donors in the active infection state or ERS of mild SARS-CoV-2 infection were associated with higher incidences of aGvHD in transplants from related donors.

Mesenchymal stromal cells plus basiliximab improve the response of steroid-refractory acute graft-versus-host disease as a second-line therapy: a multicentre, randomized, controlled trial.

BACKGROUND: For patients with steroid-refractory acute graft-versus-host disease (SR-aGVHD), effective second-line regimens are urgently needed. Mesenchymal stromal cells (MSCs) have been used as salvage regimens for SR-aGVHD in the past. However, clinical trials and an overall understanding of the molecular mechanisms of MSCs combined with basiliximab for SR-aGVHD are limited, especially in haploidentical haemopoietic stem cell transplantation (HID HSCT). METHODS: The primary endpoint of this multicentre, randomized, controlled trial was the 4-week complete response (CR) rate of SR-aGVHD. A total of 130 patients with SR-aGVHD were assigned in a 1:1 randomization schedule to the MSC group (receiving basiliximab plus MSCs) or control group (receiving basiliximab alone) (NCT04738981). RESULTS: Most enrolled patients (96.2%) received HID HSCT. The 4-week CR rate of SR-aGVHD in the MSC group was obviously better than that in the control group (83.1% vs. 55.4%, P = 0.001). However, for the overall response rates at week 4, the two groups were comparable. More patients in the control group used ≥ 6 doses of basiliximab (4.6% vs. 20%, P = 0.008). We collected blood samples from 19 consecutive patients and evaluated MSC-derived immunosuppressive cytokines, including HO1, GAL1, GAL9, TNFIA6, PGE2, PDL1, TGF-ß and HGF. Compared to the levels before MSC infusion, the HO1 (P = 0.0072) and TGF-ß (P = 0.0243) levels increased significantly 1 day after MSC infusion. At 7 days after MSC infusion, the levels of HO1, GAL1, TNFIA6 and TGF-ß tended to increase; however, the differences were not statistically significant. Although the 52-week cumulative incidence of cGVHD in the MSC group was comparable to that in the control group, fewer patients in the MSC group developed cGVHD involving ≥3 organs (14.3% vs. 43.6%, P = 0.006). MSCs were well tolerated, no infusion-related adverse events (AEs) occurred and other AEs were also comparable between the two groups. However, patients with malignant haematological diseases in the MSC group had a higher 52-week disease-free survival rate than those in the control group (84.8% vs. 65.9%, P = 0.031). CONCLUSIONS: For SR-aGVHD after allo-HSCT, especially HID HSCT, the combination of MSCs and basiliximab as the second-line therapy led to significantly better 4-week CR rates than basiliximab alone. The addition of MSCs not only did not increase toxicity but also provided a survival benefit.

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 .

Allogeneic stem cell transplantation is still a highly curative therapy in adults with philadelphia chromosome-positive acute lymphoblastic leukaemia.

The application of tyrosine kinase inhibitors (TKIs) and novel immunotherapies has improved outcomes in patients with Ph + acute lymphoblastic leukaemia (ALL), and the issue of whether there is still a need for stem cell transplantation has become controversial. We performed a retrospective study to explore whether stem cell transplantation still held a place in patients with Ph + ALL if only imatinib and 2nd generation TKIs are available and affordable. A total of 292 patients were included. The median age was 38 years [range 14-64, IQR 28-48]. Patients receiving transplants (n = 216) had better rates of 4-year disease-free survival (DFS, 68% vs. 24%, P < .0001) and overall survival (OS, 72% vs. 47%, P < .0001) than those receiving continuous TKIs plus chemotherapy (TKI-chemo) (n = 76). In the multivariate analysis, male sex, WBC count ≥ 95 × 109/L and PLT count ≤ 154 × 109/L at diagnosis were significantly associated with poorer outcomes, and transplantation was significantly associated with favourable DFS and OS. In addition, the transplant outcomes were superior in any subgroup according to the number of risk variables. Furthermore, propensity score matching (PSM) analyses showed similar findings in the whole cohort and in age- and BCR-ABL1 level-based subgroups after the first or second consolidation. In conclusion, transplantation as a one-time procedure for adults with Ph + ALL patients remains important in countries lacking accessibility to third-generation TKIs or immunotherapies, regardless of the depth of the molecular response.

Clinical characteristics and outcomes of allogeneic hematopoietic stem cell transplantation recipients with coronavirus disease 2019 caused by the Omicron variant: a prospective, observational cohort study.

We aimed to describe the clinical characteristics, particularly the occurrence and risk factors of severe/critical illness, in allogeneic hematopoietic stem cell (allo-HSCT) recipients infected with coronavirus disease 2019 (COVID-19) caused by Omicron variant in an observational prospective study (n = 311). The median time from allo-HSCT to COVID-19 diagnosis was 8.5 months (range 0.8-106.1) months. Four patients (1.3%) were reported to be asymptomatic during Omicron variant infection, and 135 (43.4%) patients showed lower respiratory tract disease. Thirty-four (10.9%) patients were categorized into serious infection (severe illness n = 25; critical illness n = 9) and the median duration from COVID-19 diagnosis to serious infections was 6 days (range, 0-29) days. Thirteen (4.2%) and 6 (1.9%) patients required intensive care unit care and invasive mechanical ventilation, respectively. Receiving more than 1 type of immunosuppressive therapies at COVID-19 diagnosis was associated with severity and persistence of infection. Six patients (1.9%) died after diagnosis of COVID-19 infection. The 4-week probability of overall survival after COVID-19 diagnosis was 98.7%, which was 100% and 88.2% for non-serious and serious infection group (P < 0.001), respectively. Thus, we observed a relatively low serious infection and mortality rate in allo-HSCT recipients infected with COVID-19 caused by Omicron variant.

CD56bright NK cell expansion correlated with EBV reactivation control post allogeneic hematopoietic stem cell transplantation.

Natural killer (NK) cells are equipped with anti-Epstein-Barr virus (EBV) function, however, whether EBV infection will affect NK cells reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains unclear. To identify the characteristics of NK cells, we prospectively enrolled 11 patients who occurred EBV reactivation post allo-HSCT and 11 patients without EBV infection as control. We found that that EBV infection induced the expansion of CD56bright and NKG2A+KIR- NK subsets,and decreased the cytotoxicity function of NK cells. The frequency of NKG2A+KIR- NK cells were higher in patients who progressed into post-transplant lymphoproliferative disorder (PTLD) than EBV viremia patients, which also correlated with decreased proliferation and cytotoxic function. By screening the activation receptors of NK cells, we found the DNAM-1+CD56bright NK cells is significantly increased after EBV stimulation, further we demonstrated that DNAM-1 is essential for EBV induced NK cells activation as the cytokine release against EBV-transformed lymphoblastoid cell lines(EBV-LCLs) of CD56bright NK cells were significantly decreased after DNAM-1 blockade. NK cells infusion suppressed the progression of EBV-related tumor mice model. A prospective cohort indicated that old donor age was an independent risk factor for EBV infection. Rapid CD56bri expansion and high expression of DNAM-1 on CD56bri NK cells in response to EBV reactivation correlated with rapid EBV clearance post allo-HSCT in patients with younger donors. In summary, our data showed that high expression of DNAM-1 receptors on NK cell may participate protective CD56bri NK cells response to EBV infection after allo-HSCT.

Clinical manifestations, prognostic factors, and outcomes of adenovirus pneumonia after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Severe pneumonia is one of the most important causes of mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Adenovirus (ADV) is a significant cause of severe viral pneumonia after allo-HSCT, and we aimed to identify the clinical manifestations, prognostic factors, and outcomes of ADV pneumonia after allo-HSCT. METHODS: Twenty-nine patients who underwent allo-HSCT at the Peking University Institute of Hematology and who experienced ADV pneumonia after allo-HSCT were enrolled in this study. The Kaplan-Meier method was used to estimate the probability of overall survival (OS). Potential prognostic factors for 100-day OS after ADV pneumonia were evaluated through univariate and multivariate Cox regression analyses. RESULTS: The incidence rate of ADV pneumonia after allo-HSCT was approximately 0.71%. The median time from allo-HSCT to the occurrence of ADV pneumonia was 99 days (range 17-609 days). The most common clinical manifestations were fever (86.2%), cough (34.5%) and dyspnea (31.0%). The 100-day probabilities of ADV-related mortality and OS were 40.4% (95% CI 21.1%-59.7%) and 40.5% (95% CI 25.2%-64.9%), respectively. Patients with low-level ADV DNAemia had lower ADV-related mortality and better OS than did those with high-level (≥ 106 copies/ml in plasma) ADV DNAemia. According to the multivariate analysis, high-level ADV DNAemia was the only risk factor for intensive care unit admission, invasive mechanical ventilation, ADV-related mortality, and OS after ADV pneumonia. CONCLUSIONS: We first reported the prognostic factors and confirmed the poor outcomes of patients with ADV pneumonia after allo-HSCT. Patients with high-level ADV DNAemia should receive immediate and intensive therapy.

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.