Post-allogeneic Hematopoietic Stem Cell Research Articles

Pulmonary complications post allogeneic haematopoietic stem cell transplant in children.

Haematopoietic stem cell transplant (HCT) is a cellular therapy that, whilst curative for a child's underlying disease, carries significant risk of mortality, including because of pulmonary complications. The aims of this study were to describe the burden of pulmonary complications post-HCT in a cohort of Australian children and identify risk factors for the development of these complications. Patients were identified from the HCT databases at two paediatric transplant centres in Australia. Medical records were reviewed, and demographics, HCT characteristics and pulmonary complications documented. Relative risk ratio was used to identify risk factors for developing pulmonary complications prior to first transplant episode, and survival analysis performed to determine hazard ratio. In total, 243 children underwent transplant during the study period, and pulmonary complications occurred in 48% (117/243) of children. Infectious complications were more common (55%) than non-infective complications (18%) and 26% of patients developed both. Risk factors for the development of pulmonary complications included the following: diagnoses of MPAL (RR 2.16, P = 0.02), matched unrelated donor (RR1.34, P = 0.03), peripheral blood (RR 1.36, P = 0.028) or cord blood (RR 1.73, P = 0.012) as the stem cell source and pre-existing lung disease (RR1.72, P < 0.0001). Children with a post-HCT lung complication had a significantly increased risk of mortality compared with those who did not (HR 3.9, P < 0.0001). This study demonstrates pulmonary complications continue to occur frequently in children post-HCT and contribute significantly to mortality. Highlighting the need for improved strategies to identify patients at risk pre-transplant and enhanced treatments for those who develop lung disease.

Efficacy of Ruxolitinib With Corticosteroids in Idiopathic Pneumonia Syndrome Post-Allogeneic Hematopoietic Stem Cell Transplantation: A Single- Center Experience and Systematic Review

Efficacy of Ruxolitinib With Corticosteroids in Idiopathic Pneumonia Syndrome Post-Allogeneic Hematopoietic Stem Cell Transplantation: A Single- Center Experience and Systematic Review

CT-132 Efficacy of Ruxolitinib With Corticosteroids in Idiopathic Pneumonia Syndrome Post-Allogeneic Hematopoietic Stem Cell Transplantation: A Single-Center Experience and Systematic Review

CT-132 Efficacy of Ruxolitinib With Corticosteroids in Idiopathic Pneumonia Syndrome Post-Allogeneic Hematopoietic Stem Cell Transplantation: A Single-Center Experience and Systematic Review

Seven-years post allogeneic hematopoietic stem cell transplantation pure red cell aplastic anemia cured with daratumumab: A case report and review of literature

BACKGROUND Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is currently the only viable method of curing patients with acute myeloid leukaemia. In 30% to 50% of patients, donors and recipients have some level of ABO blood group incompatibility. ABO blood group incompatibility can cause antibodies against the donor's red blood cells to persist in the recipient's body, resulting in a delay of several months in the recovery of red blood cells. A number of different treatments have been reported for post-transplant pure red cell aplastic anaemia (PRCA), such as plasmapheresis, donor lymphocyte infusions, anti-thymocyte globulin, rituximab and steroids. CASE SUMMARY A 41-year-old female diagnosed with acute myeloid leukaemia underwent peripheral blood allogeneic haematopoietic stem cell transplantation in November 2013 from an HLA matched unrelated donor. The donor was AB-positive and the recipient was O-positive. The patient was diagnosed with PRCA three months after receiving the donor stem cell transplant. After failing multiple lines of therapy, the patient applied for daratumumab. After receiving three doses of daratumumab, the patient developed a reticulocyte response and no longer required blood transfusions. CONCLUSION The use of daratumumab anti-CD38 for the remove of plasma cells is safe and effective and may be tried for refractory patients with PRCA after undergoing allo-HSCT for ABO incompatibility.

Spontaneous remission of de novo membranous nephropathy in post-allogeneic hematopoietic stem cell transplantation patients: A report of two cases.

Membranous nephropathy (MN) is one of the most common de novo glomerular diseases developing in patients after allogeneic hematopoietic stem cell transplantation (HSCT). Most authors have used immunosuppression for its treatment to target the underlying immune-mediated processes, akin to graft-versus-host disease, but the optimal management is currently unclear. Limited reports in the literature described the use of a conservative approach with success, particularly in cases with lower risks of progression, such as non-nephrotic-range proteinuria or early reduction of proteinuria by 6 months. We report two cases of post-HSCT MN with moderate risk features, namely prolonged durations of nephrotic-range proteinuria, that spontaneously resolved with conservative treatment. Patient 1 was of advanced age and in an immunocompromised state, while patient 2 was in need of a greater graft-versus-disease effect from the donor's immune system, which necessitated a balance between the risk of immunosuppression and the risk of progressive kidney function loss. These cases demonstrated that conservative treatment can be a reasonable approach in selected patients with post-HSCT MN, including those with moderate risk.

QuantiFERON monitor predicts early cytomegalovirus infection and viral burden in allogeneic hematopoietic stem cell transplantation.

Cytomegalovirus (CMV) infection is a major cause of transplantation-related morbidity and mortality. This study assessed the utility of the QuantiFERON monitor (QFM; Qiagen) for the prediction of early CMV infection and viral burden. QuantiFERON-CMV (QF-CMV; Qiagen) and QFM were measured at the post-allogeneic hematopoietic stem cell transplantation (HSCT) week 4. CMV DNA was measured at every visit until post-HSCT week 24. The QFM cutoff specific to CMV infection was established. At the post-HSCT week 4, the QFM cutoff predicting CMV infection was 86.95 IU/mL. While QF-CMV results at the post-HSCT week 4 were associated with high-level CMV infection (CMV DNA ≥ 5,000 IU/mL) but not with CMV infection (CMV DNA ≥ 500 IU/mL), QFM was associated with both CMV infection and high-level CMV infection. Both indeterminate QF-CMV and nonreactive QFM were associated with increased peak CMV DNA. Low QFM is a risk factor for CMV infection and increased CMV viral loads. QFM at post-HSCT week 4 can be utilized as an assay to predict the risk and burden of early CMV infection in HSCT recipients, in conjunction with other risk factors.

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.

Expansion of effector memory Vδ2neg γδ T cells associates with cytomegalovirus reactivation in allogeneic stem cell transplant recipients.

Cytomegalovirus (CMV) reactivation is a significant concern following allogeneic stem cell transplantation. While previous research has highlighted the anti-CMV reactivation effect of γδ T cells in immunocompromised transplant patients, their characterization in recipients at high risk of CMV reactivation remains limited. This study focused on D+/R+ recipients (where both donor and recipient are CMV seropositive) at high risk of CMV reactivation. We analyzed 28 patients who experienced CMV recurrence within 100 days post-allogeneic hematopoietic stem cell transplantation, along with 36 matched recipients who did not experience CMV recurrence. Clinical data from both groups were compared, and risk factors for CMV reactivation were identified. Additionally, CMV viral load was measured, and flow cytometric analysis was conducted to assess changes in peripheral blood γδ T cell proportions, subpopulation distribution, and differentiation status. We also analyzed the CDR3 repertoire of the TCR δ chain in different γδ T cell subsets. Functional analysis was performed by measuring the lysis of CMV-infected cells upon stimulation. CMV reactivation post-transplantation was associated with acute graft-versus-host disease (aGvHD) and reactivation of non-CMV herpesviruses. Notably, CMV reactivation led to sustained expansion of γδ T cells, primarily within the Vδ2neg γδ T cell subpopulation, with a trend toward differentiation from Naive to effector memory cells. Analysis of the δ chain CDR3 repertoire revealed a delay in the reconstitution of clonal diversity in Vδ2neg γδ T cells following CMV reactivation, while Vδ2pos T cells remained unaffected. Upon stimulation with CMV-infected MRC5 cells, the Vδ2neg γδ T cell subpopulation emerged as the primary effector cell group producing IFN-γ and capable of lysing CMV-infected cells. Moreover, our findings suggest that NKG2D is not necessary involved in Vδ2neg γδ T cell-mediated anti-CMV cytotoxicity. This study provides novel insights into the role of γδ T cells in the immune response to CMV reactivation in transplantation recipients at high risk of CMV infection. Specifically, the Vδ2neg γδ T cell subpopulation appears to be closely associated with CMV reactivation, underscoring their potential role in controlling infection and reflecting CMV reactivation in HSCT patients.

Association of the pre-transplant CD4/CD8 ratio with the prognosis following allogeneic hematopoietic stem cell transplantation

The tumor microenvironment’s cells can promote or inhibit tumor formation, and there are no reports on the CD4/CD8 ratio’s association with outcomes post allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively evaluated the pre-transplant peripheral blood CD4/CD8 ratio in 168 patients who underwent their first allo-HSCT for hematological malignancies at our institution. When patients were divided into two groups according to the median CD4/CD8 ratio 1.35 (range, 0.09–19.89), the high CD4/CD8 ratio group had a higher incidence of relapse, equivalent non-relapse mortality and worse overall survival (OS) than the low CD4/CD8 ratio group. In a multivariate analysis, the CD4/CD8 ratio was significantly associated with an increased risk of relapse, although there was a marginally significant difference in OS. The pre-transplant peripheral blood CD4/CD8 ratio could be a novel biomarker for predicting the prognosis of allo-HSCT.

Clinical Characteristics and Prognoses of Mucormycosis in Four Children.

Mucormycosis is a fatal invasive fungal infection that commonly affects immunocompromised children. The aim of our study was to investigate the clinical manifestations, treatments, and prognosis of pediatric patients with mucormycosis. We conducted a retrospective search in Shenzhen Children's Hospital from July 2013 to July 2023 for all patients with mucormycosis. The clinical manifestation, pathogen detection, radiology, treatments, and prognosis were analyzed. Four cases were identified. Underlying conditions included acute myeloid leukemia with myeloid sarcoma (n = 1), thalassemia (post-allogeneic hematopoietic stem cell transplantation; n = 1), systemic lupus erythematosus (n = 1), and bilateral nephroblastoma (post-bilateral nephrectomy; n = 1). Two patients were disseminated mucormycosis, one case was pulmonary mucormycosis, and one case was cerebral mucormycosis. Fever, cough, and dyspnea were the main clinical symptoms of pulmonary mucormycosis, headache was the main clinical symptom of cerebral mucormycosis. Lung CT findings included consolidation, multiple nodules, halo sign, air crescent sign, and pleural effusion. The contrast-enhanced CT showed pulmonary artery and pulmonary vein occlusions in two patients and pseudoaneurysm in two patients. Amphotericin B formulations were administered as first-line therapy in all cases; in three cases, Triazole was administered in combination with amphotericin B. Mucormycosis is a life-threatening disease involving multiple systems. Aorta pseudoaneurysm is a rare and fatal complication, enhanced CT can assist in diagnosis. Early diagnosis and appropriate therapeutic strategies are needed.

Reactivation of Multidrug-Resistant HSV-1 in a Post-Allogenic Hematopoietic Stem Cell Transplant Patient: Dynamic Detection of the Rare A605V Mutation by Next-Generation Sequencing.

We present an immunocompromised patient with a multiresistant herpes simplex virus-1 reactivation with a rare mutation (A605V) in the viral DNA polymerase gene. Next-generation sequencing suggests the presence of multiple drug-resistant strains before treatment and altered ratios during treatment, affecting the clinical response to aciclovir and foscarnet.

Treatment of post-allogeneic hematopoietic stem cell transplant cytopenias with sequential doses of multipotent mesenchymal stromal/stem cells

Background aimsCytopenias after allogeneic stem cell transplantation (allo-SCT) are a common complication, the underlying pathogenic mechanisms of which remain incompletely understood. Multipotent mesenchymal stromal/stem cell (MSC) therapy has been successfully employed in the treatment of immune-related disorders and can aid in the restoration of the hematopoietic niche. MethodsA phase II clinical trial to assess the efficacy and safety of administering four sequential doses of ex-vivo expanded bone marrow MSCs from a third-party donor to patients with persistent severe cytopenias after allo-SCT was performed. ResultsThe overall response rate on day 90 was 75% among the 27 evaluable patients (comprising 12 complete responses, 8 partial responses, and 7 with no response). The median time to respond was 14.5 days. Responses were observed across different profiles, including single or multiple affected lineages, primary or secondary timing, and potential immune-mediated or post-infectious pathophysiology versus idiopathic origin. With a median follow-up for surviving patients of 85 months after MSC infusion, 53% of patients are alive. Notably, no adverse events related to MSC therapy were reported. ConclusionsIn summary, the sequential infusion of third-party MSCs emerges as a viable and safe therapeutic option, exhibiting potential benefits for patients experiencing cytopenias following allo-SCT.

Antiviral cellular therapy for enhancing T-cell reconstitution before or after hematopoietic stem cell transplantation (ACES): a two-arm, open label phase II interventional trial of pediatric patients with risk factor assessment

Viral infections remain a major risk in immunocompromised pediatric patients, and virus-specific T cell (VST) therapy has been successful for treatment of refractory viral infections in prior studies. We performed a phase II multicenter study (NCT03475212) for the treatment of pediatric patients with inborn errors of immunity and/or post allogeneic hematopoietic stem cell transplant with refractory viral infections using partially-HLA matched VSTs targeting cytomegalovirus, Epstein-Barr virus, or adenovirus. Primary endpoints were feasibility, safety, and clinical responses (>1 log reduction in viremia at 28 days). Secondary endpoints were reconstitution of antiviral immunity and persistence of the infused VSTs. Suitable VST products were identified for 75 of 77 clinical queries. Clinical responses were achieved in 29 of 47 (62%) of patients post-HSCT including 73% of patients evaluable at 1-month post-infusion, meeting the primary efficacy endpoint (>52%). Secondary graft rejection occurred in one child following VST infusion as described in a companion article. Corticosteroids, graft-versus-host disease, transplant-associated thrombotic microangiopathy, and eculizumab treatment correlated with poor response, while uptrending absolute lymphocyte and CD8 T cell counts correlated with good response. This study highlights key clinical factors that impact response to VSTs and demonstrates the feasibility and efficacy of this therapy in pediatric HSCT.

A phase II study of belumosudil for chronic graft-versus-host disease in patients who failed at least one line of systemic therapy in China

BackgroundChronic graft-versus-host disease (cGVHD) is an immune-related disorder that is the most common complication post-allogenic hematopoietic stem cell transplant. Corticosteroids with or without calcineurin inhibitors (CNIs) remain the mainstay of cGVHD treatment for first-line therapy. However, for many patients, cGVHD symptoms cannot be effectively managed and thus require second-line therapy. Currently, there is no approved treatment for second-line cGVHD treatment in China. In this study, belumosudil, a highly selective and potent rho-associated coiled-coil-containing protein kinase-2 inhibitor demonstrated to be effective for cGVHD in the United States and other Western countries, is investigated in patients with cGVHD in China for its overall benefit–risk balance.MethodsThis multicenter, open-label phase II study evaluated the safety, efficacy, and pharmacokinetics of oral belumosudil 200 mg once daily in cGVHD patients who had been treated with at least one line of systemic therapy in China. The primary endpoint was overall response rate (ORR); each individual patient’s response was assessed by the investigator using the 2014 National Institutes of Health consensus criteria. Secondary endpoints were duration of response (DOR), time to response (TTR), changes in Lee Symptom Scale (LSS) score, organ response rate, corticosteroid dose change, CNI dose change, failure-free survival, time-to-next-treatment, overall survival, and safety.ResultsThirty patients were enrolled in the study with a median follow-up time of 12.9 months. ORR was 73.3% (95% confidence interval: 54.1–87.7%) and all responders achieved partial response. Median DOR among responders was not reached and median TTR was 4.3 weeks (range: 3.9–48.1). Fifteen patients (50.0%) achieved clinically meaningful response in terms of reduction in LSS score by ≥ 7 points from baseline. Corticosteroid and CNI dose reductions were reported in 56.7% (17/30) and 35.0% (7/20) of patients, respectively. Most treatment-emergent adverse events (TEAEs) were mild to moderate in severity, with 11 patients (36.7%) experiencing grade ≥ 3 TEAEs. The most common grade ≥ 3 TEAE was pneumonia (n = 5, 16.7%).ConclusionsBelumosudil treatment demonstrated a favorable benefit–risk balance in treating cGVHD patients who previously have had standard corticosteroid therapy in China where approved second-line setting is absent.Trial registrationClinicalTrials.gov identifier NCT04930562.

The dynamics of B-cell reconstitution post allogeneic hematopoietic stem cell transplantation: A real-world study.

The immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is crucial for preventing infections and relapse and enhancing graft-versus-tumor effects. B cells play an important role in humoral immunity and immune regulation, but their reconstitution after allo-HSCT has not been well studied. In this study, we analyzed the dynamics of B cells in 252 patients who underwent allo-HSCT for 2 years and assessed the impact of factors on B-cell reconstitution and their correlations with survival outcomes, as well as the development stages of B cells in the bone marrow and the subsets in the peripheral blood. We found that the B-cell reconstitution in the bone marrow was consistent with the peripheral blood (p=0.232). B-cell reconstitution was delayed by the male gender, age >50, older donor age, the occurrence of chronic and acute graft-versus-host disease, and the infections of fungi and cytomegalovirus. The survival analysis revealed that patients with lower B cells had higher risks of death and relapse. More importantly, we used propensity score matching to obtain the conclusion that post-1-year B-cell reconstitution is better in females. Meanwhile, using mediation analysis, we proposed the age-B cells-survival axis and found that B-cell reconstitution at month 12 posttransplant mediated the effect of age on patient survival (p=0.013). We also found that younger patients showed more immature B cells in the bone marrow after transplantation (p=0.037). Our findings provide valuable insights for optimizing the management of B-cell reconstitution and improving the efficacy and safety of allo-HSCT.

Evaluating the Feasibility and Acceptability of a Psychosexual Intervention for Couples Post-allogeneic Hematopoietic Stem Cell Transplantation.

Allogeneic hematopoietic stem cell transplantation (HSCT) can have a long-term impact on patients' sexual functioning and consequently, their relationship satisfaction. This study aimed to examine the feasibility and acceptability of a 5-session psychosexual intervention for HSCT survivors and their partners. To be eligible patients were required to be more than 3 months post-allogeneic HSCT. The intervention comprised 2 components: (1) A psychosexual education session exploring medical/behavioral treatment options for sexual dysfunction, delivered by a specialist nurse; (2) A 4-session Emotionally-Focused Therapy-based relationship education program for couples delivered by a clinical psychologist. Measures assessing relationship quality, sexual functioning, anxiety, and depression were administered pre- and post-intervention. Feasibility was measured via participation rate, adherence and compliance with completing main measures. Acceptability of the intervention was assessed via patient/partner satisfaction surveys. Eight of 85 (9.4%) eligible patients and their partners participated in the study. Reasons for declining participation included: feeling uncomfortable due to sensitive nature of intervention; did not have any relationship/sexual function issues; and experiencing ongoing medical issues. Six of 8 couples (75%) attended at least 4 intervention sessions and 5 of 8 (62.5%) completed the main study measures post-intervention. Four couples reported that sexual satisfaction and relationship satisfaction was somewhat or much better post-intervention; 1 reported no change. Feasibility criteria were not met, with low enrolment rate, however the intervention was deemed acceptable. Couples who participated adhered to the intervention and considered it beneficial. Further strategies to identify and manage sexual concerns are required.

Flow cytometry of DNMT1 as a biomarker of hypomethylating therapies.

The 5-azacytidine (AZA) and decitabine (DEC) are noncytotoxic, differentiation-inducing therapies approved for treatment of myelodysplastic syndrome, acute myeloid leukemias (AML), and under evaluation as maintenance therapy for AML postallogeneic hematopoietic stem cell transplant and to treat hemoglobinapathies. Malignant cell cytoreduction is thought to occur by S-phase specific depletion of the key epigenetic regulator, DNA methyltransferase 1 (DNMT1) that, in the case of cancers, thereby releases terminal-differentiation programs. DNMT1-targeting can also elevate expression of immune function genes (HLA-DR, MICA, MICB) to stimulate graft versus leukemia effects. In vivo, there is a large inter-individual variability in DEC and 5-AZA activity because of pharmacogenetic factors, and an assay to quantify the molecular pharmacodynamic effect of DNMT1-depletion is a logical step toward individualized or personalized therapy. We developed and analytically validated a flow cytometric assay for DNMT1 epitope levels in blood and bone marrow cell subpopulations defined by immunophenotype and cell cycle state. Wild type (WT) and DNMT1 knock out (DKO) HC116 cells were used to select and optimize a highly specific DNMT1 monoclonal antibody. Methodologic validation of the assay consisted of cytometry and matching immunoblots of HC116-WT and -DKO cells and peripheral blood mononuclear cells; flow cytometry of H116-WT treated with DEC, and patient samples before and after treatment with 5-AZA. Analysis of patient samples demonstrated assay reproducibility, variation in patient DNMT1 levels prior to treatment, and DNMT1 depletion posttherapy. A flow-cytometry assay has been developed that in the research setting of clinical trials can inform studies of DEC or 5-AZA treatment to achieve targeted molecular pharmacodynamic effects and better understand treatment-resistance/failure.

The impact of donor-specific antibodies' presence on the outcome post-allogeneic hematopoietic stem cell transplantation: a survey from a single center.

Donor-specific antibodies (DSAs) correspond to anti-HLA antibodies of the recipient that are specifically directed to a mismatched antigen of the donor. In the setting of solid organ transplantation DSAs are associated with rejection. Their role is still debated in allogeneic cell transplantation. International guidelines recommend testing patients for DSA before transplant, and if possible, choosing a donor with negative screening. We collected clinical data of 236 recipients of alloSCT, performed at our institution from March 2019 to October 2023, to evaluate their impact on engraftment. Serum from all patients was tested for DSA. 186 patients (79%) achieved sustained myeloid engraftment within day 30 post alloSCT. Thirty-two out 236 (13%) patients engrafted after day 30 post alloSCT. The median times to neutrophil engraftment and platelet engraftment were respectively 21 days (range 11-121 days) and 19 days (range 10-203 days). Fourteen out 236 patients (6%) experienced PrGF. .Twenty-nine patients (12 %) were DSA-positive. Among 29 patients with DSA positivity, 17 had a haploidentical donor and 12 had a UD donor. DSA positivity directly correlates respectively with neutrophil and platelets engraftment failure at 30 days after alloSCT (p=0.01 and p= 0.0004). Univariate Cox analysis showed that factors, including DSAs positivity, disease type, disease status, donor type, conditioning regimen, patient's age, and CD34+ were correlated with neutrophil and platelet engraftment failure at 30 days after alloSCT. Younger patients with DSA negativity, with acute leukemia, in complete response at the time of transplant, who received a higher dose of CD34+ cells from a sibling donor after a myeloablative conditioning regimen, have a reduced risk of neutrophil and platelet engraftment failure at day +30 post alloSCT.Multivariate analysis confirmed the impact of the presence of DSA only for platelet engraftment, confirming the role of type and status disease, donor type, recipient age, and CD34+ cells infused on engraftment. DSA presence has no impact on TRM, DFS, and OS. PrGF has a multifactorial pathogenesis, where DSA is not the only player, but its impact could vary depending on the transplant platform. Thus patient screening may be helpful to choose the best donor and transplant strategy.

Zinc Status Affects T Cell Reconstitution in Patients Receiving Naïve T Cell Depleted Allogeneic HSCT

Delayed immune reconstitution (IR) is a major clinical problem contributing to post-allogeneic hematopoietic stem cell transplant (allo-HSCT) morbidity and mortality. Specifically, CD4 T cell reconstitution is linked with improved clinical outcomes. As the primary organ of T cell production, the thymus is a crucial contributor to T cell reconstitution after HSCT generating a broad T cell receptor (TCR) repertoire selected through central tolerance However, T cell reconstitution can be hindered by poor thymus function as a consequence of age, transplant conditioning, or graft versus host disease (GVHD). At present, no drugs are available to boost T cell recovery, while many of the factors limiting IR are still unknown. Zinc (Zn), the second most abundant trace element in our body, is important for normal T cell development. Zn deficiency (ZD) in humans and mice is characterized by poor circulating T cells and depressed thymic function, which are both restorable after reintroduction of Zn with the diet. Despite having multiple risk factors for ZD, there are no published data focusing on ZD prevalence among allo-HSCT recipients. Based on our previous observations, we hypothesized that peri-HSCT Zn levels correlate with IR. In this study, we analyzed serum Zn levels of allo-HSCT patients who received naïve T cell (T N) depleted grafts as a strategy to prevent aGVHD (Bleakley et al., 2022, NCT00914940). This population is particularly interesting for studying IR because in these patients, circulating T N at d+365 after HSCT will primarily be of donor hematopoietic stem cell origin generated in the recipient thymus. Samples and clinical data were prospectively collected. Fifty-two patients had peri-HSCT serum samples available for Zn measures, as pre-HSCT and/or day +80 samples. Zn measures were performed through mass-spectrometry at the University of Washington Hospital-Biochemistry Lab. ZD was defined for Zn&amp;lt;70ug/dL as defined by the WHO. T cell populations (CD4 +, CD8 +, T N CD4 + and CD8 +, T regulatory cells, NK cells, B cells) were analyzed by flow cytometry at day+365. DNA was extracted from PBMC pellets collected at d+365 and were analyzed in qPCR for the expression of signal-joint T cell receptor excision circles (sjTRECs), being the gold standard for measuring thymic-derived T cells. We studied the association between Zn levels at baseline and day+80 and parameters of IR through linear regression. Comparisons between two groups were analyzed by t-test. Median age at transplant was 47 (range 6-61). Twenty-eight patients received myeloablative conditioning with total body irradiation (TBI) of 13.2 Gy (53.8%) and 24 (46.2%) received an intermediate intensity conditioning regimen with 4Gy TBI. Forty-one patients (78.8%) had pre-HSCT and 46 (88.5%) had day+80 Zn measures; 38 patients (73.1%) had both pre-HSCT and day+80 Zn measures. Median pre-HSCT and day+80 Zn levels were, respectively, 71 (range 60-105) and 80 (range 36-112); at baseline, 13 patients (25%) had ZD (&amp;lt;70ug/dL, according to WHO), whereas seven (13.3%) were ZD at day+80. Median sjTRECs at day +365 were 3.33/mg of DNA (range 0.00-16,704.54). As expected, sjTRECs at day+365 significantly correlated with age at transplant (r 2=0,3824; p&amp;lt;0.0001), whereas Zn levels preHCT or day80 did not. The number of circulating CD4 + and CD8 + T N at day+365 showed significant correlation with age. Zinc levels did not correlate with IR of absolute CD4 +, CD8 +, NK, T regs, and B cells at day+365, although we observed a trend for lower CD4 + counts at day 365 with lower day+80 Zn levels. Day+80 serum Zn levels was associated with sjTRECs at day+365 (Figure 1A. r 2=0.2643; p=0.0019) and lower pre-HSCT Zn significantly correlated with worse CD8 +T N reconstitution at day+365 (Figure 1B. r 2=0.1433; p= 0.0327), with clear trends in the same direction also for pre-HSCT Zn and CD4 + T N and day+80 Zn and CD4 + T N. In conclusion, we found that a non-negligible population of patients undergo allo-HSCT with unrecognized ZD. Peri-transplant Zinc status negatively affects IR, especially on the thymic-derived T cell compartment. Early recognition of ZD and zinc supplementation might help prevent morbidity related to poor IR in a proportion of patients. A multivariable analysis looking at other clinical data and outcomes is ongoing. Validation of these findings is needed on a larger number of patients, including a cohort of patients receiving T N-replete HSCT.

Inotuzumab Ozogamicin in Lymphoid B Cell Malignancy：a Single Center Analysis in the Real World

Background : Recent developments in immunoconjugate usage has changed the landscape of lymphoid B-cell malignancy therapy. Historically, those who relapse from this condition have a dismal prognosis and limited treatment options. One recent development is the inotuzumab ozogamicin (INO), a humanized anti-CD22 monoclonal antibody conjugated to the cytotoxic antibiotic calicheamicin, which has the potential to reduce the overall toxicity of intensive regimens for ALL, as well as to show therapeutic effects in lymphoid B-cell malignancy. Aims and Methods: The study included B cell-acute lymphoblastic leukemia (B-ALL) (n=23), B/ myeloid mixed phenotype acute leukemia (MPAL) (n=1) and B-cell lymphoblastic lymphoma (B-LBL) (n=3) adult patients who received INO in our center from June 2022 to June 2023. Intravenous INO was given 1 or more doses at the dose of 0.6mg/m2, its clinical efficacy and adverse reactions were explored. Results: In our center, INO was strategically employed in various therapeutic scenarios: induction (n=2), maintenance/consolidation (n=6), minimal residual disease (MRD) clearance (n=5), and the management of relapsed/refractory lymphoid B-cell malignancies (n=14). Of the 27 patients, 14 were subjected to a combination regimen of INO and chemotherapy for recurrent and refractory lymphoid B-cell malignancy. The composition of these patients comprised of 4 individuals who experienced a relapse post-standard chemotherapy, 1 patient with a relapse post-allogeneic hematopoietic stem cell transplantation (allo-HSCT), 4 patients with a relapse post-autologous hematopoietic stem cell transplantation (auto-HSCT), and the remaining 5 patients were categorized as refractory cases. The median number of doses administered was 2 (1-3). Complete remission (CR) or CR with incomplete hematologic recovery (CRi) was observed in 9 out of 14 patients (64.3%) within a median duration of 30 (16-78)days. Partial response (PR) was noted in 2 of the 14 patients (14.3%), rendering the overall response rate (ORR) to be 78.6%. Negative MRD was observed in 7 out of 14 patients (50.0%). Of the 9 patients who achieved CR/CRi, 4 (44.4%) relapsed again with 2 fatalities. The remaining 2 patients attained negative MRD following a second allo-HSCT or INO retreatment. The two patients who achieved PR proceeded to receive chimeric antigen receptor T cell (CART) treatment, with one of them subsequently undergoing allo-HSCT after achieving CR. For the three non-responders (NR), one patient unfortunately passed away while the other two patients remained alive and were either participating in clinical trials or undergoing allo-HSCT after CART. For MRD clearance, it was successfully achieved in 4 out of 5 patients (80.0%)treated with INO within a median period of 45 (28-52)days. However, 2 patients reverted to MRD positivity and 1 died. The other four patients underwent allo-HSCT with neither mortality nor recurrence observed. Moreover, two patients (100%) were treated with a VICLP induction regimen combined with INO, with MRD negativity observed post-treatment. Regarding the remaining six patients, three patients were treated with INO as consolidation therapy due to high-risk factors or the intention to undergo auto-HSCT. Another 3 B-ALL patients treated with INO as maintenance therapy after auto-HSCT or after the remission of recurrence after transplantation. One patient unfortunately experienced a second recurrence four months following INO maintenance. The remaining five patients achieved and have since sustained negative MRD status, preceding INO treatment. Fortunately, no treatment-related fatalities or treatment discontinuation due to adverse events were observed. Notably, 19 out of 27 patients (70.4%) experienced Grade 3-4 hematological toxicity, while 1 out of 24 patients (4.2%) exhibited Grade 3 alanine aminotransferase (ALT) elevation. Veno-occlusive disease (VOD) was not observed. Furthermore, two patients developed septicemia, one each from Escherichia coli and Klebsiella pneumoniae, respectively. Conclusions: Given the well tolerance and improvement in response rates, InO may be an important treatment option not only for patients with relapsed/refractory lymphoid B-cell malignancy, but also for induction, maintenance and MRD clearance treatment. Key words: inotuzumab ozogamicin, acute lymphoblastic leukemia, hematopoietic stem cell transplantation, CD22