Setting Of Stem Cell Transplantation Research Articles

A Universal CRISPR/Cas9n-Mediated Genome Editing Approach for ELANE-Related Severe Congenital Neutropenia

Severe congenital neutropenia (CN) is an inherited bone marrow failure syndrome characterized by impaired maturation of neutrophil granulocytes. Due to the lack or very low levels of neutrophils in the peripheral blood, patients experience severe, life-threatening bacterial infections as early as birth. Autosomal-dominant ELANE mutations are the most common cause of CN. Although most patients respond to daily treatment with recombinant human granulocyte colony-stimulating factor, about 15% of patients do not respond to this cytokine, and approximately 20% of patients develop myelodysplasia or acute myeloid leukemia. The only curative treatment available thus far is allogenic hematopoietic stem cell transplantation, which is associated with serious side effects. Autologous transplantation of gene-edited patients' HSPCs offers a novel curative therapy. Considering the wide range of mutations distributed throughout the ELANE gene, A universal, high-safety-profile approach could be advantageous for all ELANE-CN patients. Our group has already published a universal CRISPR/Cas9-mediated knockout approach for the ELANE gene; however, targeting the coding sequence region (CDS) of the ELANE gene could lead to the introduction of new disease-causing variants, so it may be harmful for patients. In order to address this concern, we reformatted our previously published knockout concept into a clinical-grade gene therapy strategy. We have screened cis-regulatory regions in the ELANE core promoter and, using CRISPR/Cas9n, introduced two nicks on opposing strands of the Goldberg-Hognes box region (TATA-box) to make the transcription starting process inefficient, as transcription factors and RNApol II cannot recognize the modified sequence. Theproposed strategy targets the non-coding region of the ELANE gene and thus does not generate new unwanted variants. Also, by replacing Cas9 with Cas9-ncikase, the off-target activity should decrease by up to 1000-fold. We have observed a markedly elevated neutrophil differentiation in gene-edited ELANE-CN patients HSPCs (n = 2), as assessed by the percentage of CD45 +CD11b +CD15 +, CD45 +CD15 +CD16 +, and CD45 +CD16 +CD66b + myeloid/granulocytic cells, compared to the mock electroporated ELANE-CN group, while no disruption of granulopoiesis in healthy donor HSPCs (n = 2) was detected. Results validated by the CFU assay. To have nucleotide-level resolution of on-target events, we performed targeted next-generation sequencing of edited loci on gene-edited healthy donors and ELANE-CN HSPCs. Next-generation sequencing results showed >90% on-target efficiency. CRISPR/Cas9n-mediated targeting of the TATA box rescued defective granulopoiesis in vivo, as gene-edited ELANE-CN HSPCs (n = 3) were transplanted in NSG mice and assessed by the percentage of neutrophils (hCD19 -hCD3 -hCD66b Int/lowhCD33 +hCD16 high) after 16 weeks. We have also observed efficient engraftment and preserved the multilineage potential of gene edited HSPCs in immunodeficient NSG mice. The strategy also depicted a safe profile upon applying gene editing to healthy donor CD34 + HSPCs and performing GUIDE-seq and CAST-seq. GUIDE-seq highlighted two potential off-target sites after >=6 mismatches, while no chromosomal translocations were detected by CAST-seq. RNA-sequencing of in vitro-generated neutrophils from gene-edited HSPCs of healthy donors (n = 2) confirmed a >9-fold reduction of ELANE gene expression level. Important to note, none of the other serine proteases or neighboring genes were down-regulated. Taken together, ex vivo CRISPR-Cas9n-based gene editing of ELANE's gene promoter in the setting of autologous stem cell transplantation could be a safe therapeutic approach for all ELANE-CN patients.

Post-Transplant Cyclophosphamide (PTCY) Compared to ATG in Patients with Myelodysplastic Neoplasms Allografted with an Unrelated Donor: A Registry Study of the Chronic Malignancies Working Party of the EBMT

Background Prospective randomized trials have reported a benefit for ATG-based GVHD prophylaxis in the setting of allogeneic hematopoietic stem cell transplantation (alloHSCT) with an unrelated donor (UD). However, the best GVHD prophylaxis has been recently challenged by the use of PTCY, first in haplo-identical transplant and then in HLA mismatched or matched unrelated transplantation. We here present the outcomes of PTCY vs ATG as GVHD prophylaxis in MDS patients from the EBMT registry transplanted with an unrelated donor. Method A total of 969 patients transplanted from 2012 to 2019 in 92 participating centers, receiving either PTCY or ATG, were included in this study. The primary outcomes were progression free survival (PFS) and overall survival (OS). Competing risks analyses were performed to analyze non-relapse mortality (NRM) with competing event relapse, and acute GvHD grade II-IV, chronic GvHD and neutrophil engraftment with competing events relapse and death. Cox proportional hazards regression with a predefined covariate constellation (age, IPSS-R cytogenetics, donor HLA matching, age, hypomethylating agents (HMA) prior to transplantation, comorbidity score and MDS classification (MDS with or without excess blast, EB) was used to obtain adjusted effect estimates of ATG compared to PTCY for OS and PFS. Results Overall, 214 patients received PTCY and 755 received ATG as GVHD prophylaxis for UD alloHSCT. Patients of the ATG group were older (60.1 year-old [IQR: 50.6-65.2] vs 57.2 year-old [IQR: 46.4-61.1], p=0.008). Disease characteristics were similar in both group: there were a total of 583 MDS with EB at diagnosis, 510 MDS-EB at transplantation, and 207 patients transformed into AML. Among patients with available data for IPSS-R at MDS diagnosis (n=760) 44 (5.8%) were Very Low, 114 (15%) Low, 209 (27.5%) Intermediate, 232 (30.5%) High and 161 (21.2%) Very High. Patients of the PTCY group received more frequently HMA before transplantation (72.4% vs 57.3%, p=0.001) and were preferentially transplanted from an HLA mismatched 9/10 donor (37.9% vs 21.6%, p<0.001). Conditioning regimen was more frequently myeloablative in the PTCY group (55.4% vs 38.7%, p<0.001). Neutrophil engraftment at 28 days was significantly better with ATG (93% vs 84%, p<0.001). With a median follow-up of 4.4 (95% CI 4.2 - 4.8) years, five-year OS was 57% (49-64) with PCTY and 49% (95% 46-53%) in ATG group, p=0.127. Five-year cumulative incidence of relapse was similar in both groups (22%, 95%CI 16-29 in PTCY vs 25%, 95%CI 22-28 in ATG; p=0.28). Notably, 5-year PFS was marginally higher for PTCY with 52% (95%CI 44-59) vs 44% (95%CI 40-48) for ATG, p=0.075, whereas 5-year NRM was 26% (95% CI 20-32%) vs 31% (95% CI 27-34) in PTCY and ATG, respectively, p=0.28. Grade II-IV acute GVHD incidence was lower using PTCY (22% [95% CI 17-28%] vs 30% [95% CI 26-33%]), p=0.035 while there was no difference for chronic GVHD (36% (29-43% with PTCY vs 38% (34-41%) in ATG at 5 years). Multivariable analyses confirmed a better OS and PFS for PTCY, with a HR of ATG of 1.34 (95% CI 1.02-1.76), p=0.04, and a better PFS for PTCY with a HR for ATG of 1.31 (95%CI 1.01-1.69) (Table 1). There was no apparent interaction between GvHD prophylaxis and IPSS-R or HLA matching, suggesting an effect exclusive to the type of GVHD prophylaxis used. Conclusion: This EBMT registry study suggests that MDS patients who received a transplant from an unrelated donor had a better OS and PFS using PTCY compared to ATG. This confirms that PTCY instead of ATG in this setting is a valid option.

Role of Preemptive Cytomegalovirus Hyperimmunoglobulin in Cytomegalovirus Viremia Following Stem Cell Transplant: An Integrative Review.

Cytomegalovirus (CMV) is a major cause of morbidity and mortality in stem cell transplant (SCT) patients. Cytomegalovirus hyperimmunoglobulin (CMV-HIG) therapy has been described in the solid organ transplant setting. However, no review has focused on preemptive use of intravenous CMV immunoglobulins in the SCT setting. This review aims to consolidate findings regarding the preemptive use of CMV-HIG for CMV viremia in SCT patients. PubMed and Scopus were searched using specific search criteria for publications from 2011 to 2021. Search terms were: cytomegalovirus, CMV, immunoglobulins, immunoglobulin, IVIG, CMVIG, hematopoietic stem cell transplantation, and stem cell. Included studies discussed stem cell transplantation, immunoglobulins, and cytomegalovirus. 366 articles were identified from the search. Five articles met the inclusion and exclusion criteria. Preemptive CMV-HIG resulted in an overall response in 65% to 100% of patients with a clearance time of 14 to 21 days. Early use of CMV-HIG may shorten clearance time. No treatment-related mortality or serious adverse events were associated. CMV-HIG is an effective treatment option in SCT patients that is as safe as antivirals alone. Preemptive CMV-HIG with antivirals may provide the added advantage of reduced time to viremia clearance without adding renal injury. Larger, prospective studies are needed to evaluate CMV-HIG's impact on time to viremia clearance and the effectiveness of preemptive CMV-HIG use with antivirals.

Long-Term Cryopreservation of Peripheral Blood Stem Cell Harvest Using Low Concentration (4.35%) Dimethyl Sulfoxide with Methyl Cellulose and Uncontrolled Rate Freezing at -80 °C: An Effective Option in Resource-Limited Settings

Long-term cryopreservation of peripheral blood stem cells (PBSCs) is highly useful in the setting of tandem/multiple transplantations or treatment of relapse in the autologous hematopoietic stem cell transplantation (HSCT) setting. Even in allogeneic HSCT, donor lymphocyte infusions may be stored for months to years if excess stem cells are collected from donors. Cryopreservation is a delicate, complex, and costly procedure, and higher concentrations of dimethyl sulfoxide (DMSO), a commonly used cryoprotectant, can be toxic to cells and cause adverse effects in the recipient during infusions. In this study, we examined the effect of long-term cryopreservation using 4.35% DMSO (as final concentration) with methyl cellulose and uncontrolled rate freezing in a mechanical freezer (-80 °C) on the viability and colony-forming ability of CD34+ human PBSCs. For patients undergoing autologous HSCT, PBSCs were cryopreserved using DMSO (final concentration of 4.35%) with methyl cellulose. The post-thaw viability of PBSCs was determined using Trypan blue exclusion and flow cytometry-based 7-amino-actinomycin-D (FC-7AAD) methods. Concentrations of CD34+ stem cells and immune cell subsets in post-thaw PBSC harvest samples were assessed using multicolor flow cytometry, and the clonogenic potential of post-thaw stem cells was studied using a colony-forming unit (CFU) assay. CD34+ stem cell levels were correlated with the prestorage CD34 levels using the Pearson correlation test. The viability results in the Trypan blue dye exclusion method and the flow cytometry-based method were compared using Bland-Altman plots. We studied 26 PBSC harvest samples with a median cryopreservation duration of 6.6 years (range, 3.8 to 11.5 years). The median viability of post-thaw PBSCs was >80% using both methods, with a weak agreement between them (r=.03; P=.5). The median CD34+ stem cell count in the post-thaw samples was 9.13×106/kg (range, .44 to 26.27×106/kg). The CFU assay yielded a good proliferation and differentiation potential in post-thaw PBSCs, with a weak correlation between granulocyte macrophage CFU and CD34+ stem cell levels (r=.4; P=.05). Two samples that had been cryopreserved for >8 years showed low viability. Cryopreservation of PBSCs using 4.35% DMSO with methyl cellulose and uncontrolled freezing in a mechanical freezer at -80 °C allows the maintenance of long-term viability of PBSC for up to 8 years.

Significance of CMV reactivation in non-allogeneic stem cell transplant patients with cancers: experience of single tertiary care cancer institute.

CMV reactivation is rare in hematological as well as solid organ malignancies in non-allogeneic stem cell transplant settings. An increasing number of patients undergoing active treatment or follow-up and diagnosed with CMV reactivation in recent years prompted us to investigate the risk factors and outcomes of CMV reactivation or disease. This was a hospital-based retrospective study that included 174 cancer patients suspected of CMV reactivation. Among them, forty-one tested positive for CMV viremia. The risk factors for CMV reactivation included the use of steroids in 78% of patients, active cancer in 43.9%, use of a monoclonal antibodyrituximabin 31.7%,a history of radiation in 26.8%, and autologous stem cell transplant in 12% of patients. The median age was 36 years, and the most common clinical feature was fever (58.5%; n = 24), followed by GI symptoms (12.1%; n = 5), respiratory symptoms (14.6%; n = 6), cytopenia (7.3%; n = 3), and visual/neurological symptoms (4.8%; n = 2). The mean CMV viral load was 37,332 copies/ml (range: 75.00-633,000.00 copies/ml). Nineteen patients received CMV treatment with an average treatment duration of 81.5 days. The median overall survival was 2 months, with 12.0% of patients alive at 5 years. CMV reactivation is associated with significant morbidity and mortality. We recommend vigilant monitoring of CMV-related symptoms, with a low threshold for testing and treatment, for patients with multiple risk factors for CMV reactivation.

The Role of Fecal Microbiota Transplantation in the Allogeneic Stem Cell Transplant Setting.

Microbiota changes during allogeneic hematopoietic stem cell transplantation has several known causes: conditioning chemotherapy and radiation, broad-spectrum antibiotic administration, modification in nutrition status and diet, and graft-versus-host disease. This article aims to review the current knowledge about the close link between microbiota and allogeneic stem cell transplantation setting. The PubMed search engine was used to perform this review. We analyzed data on microbiota dysbiosis related to the above-mentioned affecting factors. We also looked at treatments aimed at modifying gut dysbiosis and applications of fecal microbiota transplantation in the allogeneic stem cell transplant field, with particular interest in fecal microbiota transplantation for graft-versus-host disease (GvHD), multidrug-resistant and clostridium difficile infections, and microbiota restoration after chemotherapy and antibiotic therapy.

Predictive factors of sleep quality and burnout in nurses working in transplant units during the COVID-19 lockdown – A cross-sectional study

Background: There is minimal information regarding sleep disturbance and burnout during COVID-19 in nurses working within haematology-oncology and hematopoietic stem cell transplantation (HSCT) settings. Aim: To identify socio-demographic and professional factors that predicted burnout and sleep disturbance during COVID-19 in nurses working in HSCT settings. Design/Methods: Data were collected using the Maslach Burnout Inventory and the Pittsburgh Sleep Quality Index. Descriptive statistics and linear regression examined relationships. Results: 308 responses were received. Nurses working in outpatient settings had greater emotional exhaustion (Rpartial = −0.12, n = 308, p = 0.03). Negative predictors for quality of sleep were transplant programme setting (Rpartial = −0.19, n = 308, p < 0.01) and years working in HSCT (Rpartial = −0.17, n = 308, p < 0.01). Other relationships were found on univariate analysis. Conclusion: Institutions must offer programmes for nurses to develop sleep strategies, self-care, and work-related stress management.

A SYSTEMATIC REVIEW OF THE DIRECT COSTS ASSOCIATED WITH THE MANAGEMENT OF MUCOSITIS

Objective To evaluate and report the direct economic outcomes associated with the management of mucositis across several cancer treatments through a systematic review. Study Design A systematic search using the databases Scopus, MEDLINE/PubMed, and Embase to identify articles that provided data on costs associated with mucositis in cancer patients following antineoplastic therapies. Results 37 studies were included. The costs attributable to mucositis ranged from 1,124.47 to 29,9214.14 US dollars (USD) per patient in the hematopoietic stem cell transplantation setting; from 51.23 to 33,560.58 USD per patient in the radiotherapy/ chemoradiotherapy/radiotherapy plus molecular targeted therapy setting; from 4.18 to 31,963.64 USD per patient in the chemotherapy setting; from 565.85 to 20,279.12 USD per patient when cancer treatment was not specified; from 12.42 to 5,670.46 USD per patient for the multimodal therapy setting; and from 45.78 to 3,484.91 USD per patient in the molecular targeted therapy setting. Conclusion Mucositis is associated with increased resource use, consultations, hospitalizations and extended hospitalizations, leading to a substantial incremental cost that exacerbates the economic burden on the patient, health plan, and health system across several cancer treatments and diagnosis. More studies with a prospective evaluation of the economic costs associated with mucositis management are needed. To evaluate and report the direct economic outcomes associated with the management of mucositis across several cancer treatments through a systematic review. A systematic search using the databases Scopus, MEDLINE/PubMed, and Embase to identify articles that provided data on costs associated with mucositis in cancer patients following antineoplastic therapies. 37 studies were included. The costs attributable to mucositis ranged from 1,124.47 to 29,9214.14 US dollars (USD) per patient in the hematopoietic stem cell transplantation setting; from 51.23 to 33,560.58 USD per patient in the radiotherapy/ chemoradiotherapy/radiotherapy plus molecular targeted therapy setting; from 4.18 to 31,963.64 USD per patient in the chemotherapy setting; from 565.85 to 20,279.12 USD per patient when cancer treatment was not specified; from 12.42 to 5,670.46 USD per patient for the multimodal therapy setting; and from 45.78 to 3,484.91 USD per patient in the molecular targeted therapy setting. Mucositis is associated with increased resource use, consultations, hospitalizations and extended hospitalizations, leading to a substantial incremental cost that exacerbates the economic burden on the patient, health plan, and health system across several cancer treatments and diagnosis. More studies with a prospective evaluation of the economic costs associated with mucositis management are needed.

Absolute lymphocyte counts (ALC) recovery and risk of viral reactivation in the setting of haploidentical hematopoietic stem cell transplant.

e19065 Background: The impact of early absolute lymphocyte repopulation after allogeneic hematopoietic stem cell transplant has historically been shown to predict the risk of post-transplant infection, and subsequently, non-relapse mortality (NRM). Previous studies have shown that ALC recovery after allogeneic stem cell transplant is associated with risk of viral reactivation and survival. In this study we aim to investigate the role of ALC recovery in the contemporary era with myeloablative haploidentical hematopoietic stem cell transplant (HI-HSCT). Methods: We retrospectively analyzed adult patients at University of Southern California (USC) Norris Cancer Hospital who received myeloablative conditioning haplo-HSCT (Fludarabine with 12 Gy of radiation) from 2014 to 2020. The primary endpoint was correlation between ALC recovery day 21 and risk of viral reactivation including cytomegalovirus (CMV), Epstein-Barr Virus (EBV) and BK virus. ALC recovery cut off was chosen to be 175/uL on day +21 and 500/uL on day +60 based on prior reports. Results: 58 patients were identified as recipients of MAC haploidentical-HSCT. 17 had ALC recovery at day +21. Mean age was 49 years, 31 (53.4%) were males and 27 (46.6%) were females. 41 (70%) patients were Hispanic, 12 (20%) were non-Hispanic White, and the majority had AML (51%). 76% received &gt; 5*106/kg CD34+ cell dose and 78% received CD3 + cell dose &lt; 3*108/kg. Serum CMV, EBV and urine BK virus were detected in 38 (65.5%), 8 (15.7%) and 11 (32.4%) respectively. Clinically significant CMV reactivation (required treatment with antiviral therapy) was detected in 26 (44.8%) patients. Lack of ALC recovery on day +21 did not show correlation with CMV, EBV and BK virus reactivation. Also, the risk of CMV reactivation was not related to day +60 ALC recovery (p-value = 0.469). On univariate analysis, ALC recovery day +21, day +60, and CMV reactivation did not show correlation with overall survival. In multivariate analysis when adjusted for age and pre-transplant CMV status, higher CD 3+ cell dose of &gt; 3*108/kg was associated with reduced risk of CMV reactivation HR = 0.35 (0.15-0.85) p-value = 0.02. Conclusions: Previous studies have established ALC recovery as a predictor of better outcome. This has not been established in patients undertaking myeloablative HI-HSCT. Our study shows that lack of ALC recovery on day +21 does not affect CMV, EBV and BK virus reactivation and risk of CMV reactivation does not correlate with day +60 ALC recovery. Also, ALC recovery and CMV reactivation does not impact overall survival. The use of Letermovir, effective CMV therapies and close viral surveillance in contemporary practice is likely responsible for mitigating poor outcomes with CMV reactivation. Graft composition needs to be studied prospectively, as higher CD3+ cell dose may present an opportunity to reduce CMV reactivation in HI-HSCT.

Results of haploidentical transplant in patients with donor-specific antibodies: a survey on behalf of the Spanish Group of Hematopoietic Transplant and Cell Therapy.

Donor-specific antibodies (DSAs) are IgG allo-antibodies against mismatched donor HLA molecules and can cause graft failure (GF) in the setting of haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Our aim was to report the experience of the Spanish Group of Hematopoietic Transplant (GETH-TC) in DSA-positive patients who had undergone haplo-HSCT. We conducted a survey of patients who underwent haplo-HSCT in GETH-TC centers between 2012 and 2021. Data were collected on the DSA assay used, monitoring strategy, complement fixation, criteria for desensitization, desensitization strategies and transplant outcomes. Fifteen centers from the GETH-TC responded to the survey. During the study period, 1,454 patients underwent haplo-HSCT. Seventy of the transplants were performed in 69 DSA-positive patients, all of whom lacked a suitable alternative donor; 61 (88%) patients were female (90% with prior pregnancies). All patients received post-transplant cyclophosphamide-based graft-versus-host disease prophylaxis. Regarding baseline DSA intensity, 46 (67%) patients presented mean fluorescence intensity (MFI) >5,000, including 21 (30%) with MFI>10,000 and three (4%) with MFI >20,000. Six patients did not receive desensitization treatment, four of them with MFI <5,000. Of 63 patients receiving desensitization treatment, 48 (76%) were tested after desensitization therapy, and a reduction in intensity was confirmed in 45 (71%). Three patients (5%) experienced an increase in MFI after desensitization, two of whom experienced primary GF. Cumulative incidence of neutrophil engraftment at day 28 was 74% in a median of 18 days (IQR, 15─20); six patients died before engraftment due to toxicity or infection and eight patients had primary GF despite desensitization in seven of them. After a median follow-up of 30 months, two-year overall and event-free survival were 46.5% and 39%, respectively. The two-year cumulative incidence of relapse was 16% and non-relapse mortality (NRM) was 43%. Infection was the most frequent cause of NRM, followed by endothelial toxicity. Multivariate analysis identified baseline MFI>20,000 as an independent risk factor for survival and an increase in titers after infusion as an independent risk factor for GF. Haplo-HSCT is feasible in DSA-positive patients, with high rates of engraftment after desensitization guided by DSA intensity. Baseline MFI >20,000 and increased intensity after infusion are risk factors for survival and GF.

Flow Cytometric MRD Assessment in Acute Lymphoblastic Leukemias

AbstractAcute lymphoblastic leukemia (ALL) is one of the very first malignancy where the assessment of early response to therapy by minimal/measurable residual disease (MRD) monitoring has proven to be cardinal tool for guiding therapeutic choices. At present, MRD detection is not only used for the assessment of initial treatment response and subsequent risk stratification but also for monitoring disease burden in the setting of hematopoietic stem cell transplant. Multicolor flow cytometry (FCM) for the assessment of MRD has been in existence for more than two decades. It is presently the most commonly used technique worldwide for MRD assessment in ALL. The technique has evolved from two to three color assays in its early phases to eight and more color assays in present time, which enables detection of one leukemic cell in 104 or more cells. The assessment of MRD is based on analysis of expression of lineage-associated markers and either looking at “leukemia associated immunophenotypes” or identify “different from normal” patterns. A rapid turn-around-time and direct quantification of viable residual leukemic cells are advantages of FCM over molecular techniques of MRD assessment. On the other hand, one of the prime limitations of detection of residual cells by FCM is the immunophenotypic shifts that are observed as a result of chemotherapeutic reagents. In addition, introduction of immunotherapy, especially against important gating markers like CD19, has posed significant challenge to FCM-based MRD assays, and requires modification of antibody panels for an alternate gating and analysis strategy. Finally, standardization and validation of MRD assay and use of internal and external quality controls are extremely important aspects for a clinical laboratory providing MRD reports for patient care.

Mutations in the alternative complement pathway in multiple myeloma patients with carfilzomib-induced thrombotic microangiopathy

Thrombotic microangiopathy (TMA) has been reported to occur in multiple myeloma (MM) patients in association with treatment with carfilzomib, an irreversible proteasome inhibitor (PI). The hallmark of TMA is vascular endothelial damage leading to microangiopathic hemolytic anemia, platelet consumption, fibrin deposition and small-vessel thrombosis with resultant tissue ischemia. The molecular mechanisms underlying carfilzomib-associated TMA are not known. Germline mutations in the complement alternative pathway have been recently shown to portend increased risk for the development of atypical hemolytic uremic syndrome (aHUS) and TMA in the setting of allogeneic stem cell transplant in pediatric patients. We hypothesized that germline mutations in the complement alternative pathway may similarly predispose MM patients to carfilzomib-associated TMA. We identified 10 MM patients with a clinical diagnosis of TMA in the context of carfilzomib treatment and assessed for the presence of germline mutations in the complement alternative pathway. Ten, matched MM patients exposed to carfilzomib but without clinical TMA were used as negative controls. We identified a frequency of deletions in the complement Factor H genes 3 and 1 (delCFHR3-CFHR1) and genes 1 and 4 (delCFHR1-CFHR4) in MM patients with carfilzomib-associated TMA that was higher as compared to the general population and matched controls. Our data suggest that complement alternative pathway dysregulation may confer susceptibility to vascular endothelial injury in MM patients and predispose to development of carfilzomib-associated TMA. Larger, retrospective studies are needed to evaluate whether screening for complement mutations may be indicated to properly counsel patients about TMA risk with carfilzomib use.

Torque Teno Virus and Cancers: Current Knowledge

Aim: The aim of this systematic review is to assess the current knowledge about the relationship between Torque Teno virus (TTV) and cancer in different settings. Methods: A systematic search was conducted in Medline via PubMed, Embase and Cochrane Library from the inception to the end of January 2023. Results: 34 articles were included in the qualitative synthesis of this review and 2145 patients with solid tumors have been analyzed. The most prevalent cancer types were hepatocellular carcinoma (HCC) and lung cancer. Conclusion: TTV has proven its role as a marker of functional immune competence in the setting of hematopoietic stem cell transplantation (HSCT), but in the oncological field is yet to be defined.

481 - Health-Related Quality of Life in Patient/Primary Caregiver Dyads in the Hematopoietic Stem Cell Transplantation Setting: 6-Month Follow up Data from the We’Re in This Together Study

481 - Health-Related Quality of Life in Patient/Primary Caregiver Dyads in the Hematopoietic Stem Cell Transplantation Setting: 6-Month Follow up Data from the We’Re in This Together Study

Eight-color multiparameter flow cytometry (EuroFlow-NGF) is as sensitive as next-generation sequencing in detecting minimal/measurable residual disease in autografts of patients with multiple myeloma.

The prognostic value of minimal/measurable residual disease (MRD) detection in autografts of patients with multiple myeloma (MM) in an autologous stem-cell transplantation setting has been reported. Next-generation flow (NGF) cytometry has lower sensitivity (2×10-6) to detect MRD than next-generation sequencing (NGS) (<10-6). We compared the clinical value of high-sensitivity NGF (cutoff: <10-6) and NGS (cutoff: 10-6) for the detection of MRD in the cryopreserved autografts of 49 patients with newly diagnosed MM. The sensitivity test using frozen/thawed autografts revealed a strong correlation among MRD levels of 5×10-7 and 1×10-4 (r=0.9997, p<0.0001) when an adequate number of cells were analyzed. Autograft MRD levels determined using NGF and NGS were highly correlated (r=0.811, p<0.0001). MRD-negative patients identified with NGF (cutoff: <10-6) showed significantly longer progression-free survival (PFS) than MRD-positive patients (p=0.026). The PFS of MRD-negative patients determined by NGS (cutoff: 10-6) was similar to that determined by NGF. These results show that the high-sensitivity NGF method can assess MRD in frozen/thawed autografts, and its prognostic value is comparable to that of NGS.

Handheld Ultrasound or Conventional Ultrasound Devices in Patients Undergoing HCT: A Validation Study.

Abdominal ultrasound exams play a major role in the diagnosis of sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD). The development of portable hand-held ultrasound devices (HHUS) has been shown to facilitate the diagnosis of many diseases, but little data on the value of HHUS in the diagnosis of SOS/VOD are available. We performed a study aimed at validating portable ultrasound (US) devices in the setting of hematopoietic stem cell transplant (HCT). Sixteen evaluable patients undergoing allogeneic HCT were studied using conventional US and HHUS during the first 3 weeks after transplant. The results obtained demonstrate that there is a close correlation between conventional and handheld ultrasound examination in the measurement of the right hepatic lobe (r = 0.912, p &lt; 0.0001), the left hepatic lobe (r = 0.843, p &lt; 0.0001), the portal vein (PV) (r = 0.724, p &lt; 0.0001), and the spleen (r = 0.983, p &lt; 0.0001) based on Pearson's correlation. The same data, analyzed through Lin's concordance correlation coefficient, evidenced a substantial level of agreement in the comparison of the spleen and right hepatic lobe, while a lower grade of agreement in the measurement of the portal vein and left hepatic lobe. Moreover, there was good agreement between results obtained by the two types of ultrasound devices in assessing ascites (p &lt; 0.0001), gallbladder thickening (p &lt; 0.0001), and the direction of PV flow (p &lt; 0.0001). HHUS device allows the study of HokUs-10 parameters with an excellent agreement with conventional US, and may contribute to SOS/VOD diagnosis.

The measurement and use of patient-reported outcomes in the setting of hematopoietic stem cell transplantation

Patient-reported outcome（PRO），患者報告アウトカムは「患者の回答について，臨床医や他の誰の解釈も介さず，患者から直接得られる患者の健康状態に関するすべての報告」と定義される。有害事象報告やQOL評価において患者評価と医療者評価の間には大きな乖離があることが示されており，近年，臨床試験や日常臨床においてPROを組み込むことの重要性が認識されつつある。本邦の血液領域では二つの大規模なQOL横断的調査が行われ，GVHDや就労などのQOL関連要因が示された。また，本邦の単施設研究からは，移植前QOLと移植後成績の有意な相関が示されている。今後はPROを観察するだけではなく，臨床に活用する工夫が必要である。QOLだけでなく，二次がんや就労などの晩期アウトカムはいずれもPROであり，「医療者の負担を増やさずに，患者さんから情報をもらって，診療に生かす」という考え方が重要である。

Peripheral blood persistence and expansion of transferred non-genetically modified Natural Killer cells might not be necessary for clinical activity

Natural killer (NK) cells are innate lymphocytes that react without previous exposition to virus infected or malignant cells and stimulate adaptive immune response to build a long-lasting immunity against it. To that end, tissue resident NK cells are predominantly regulatory as opposed to cytotoxic. In the hematopoietic stem cell transplant (HSCT) setting, which curative potential relies on the graft versus leukemia effect, NK cells are known to play a significant role. This knowledge has paved the way to the active investigation on its anti-tumor effect outside the stem cell transplant scenario. Based on the relevant literature on the adoptive transfer of non-genetically modified NK cells for the treatment of relapsed/refractory acute leukemia and on our own experience, we discuss the role of donor cell peripheral blood persistence and expansion and its lack of correlation with anti-leukemia activity.

Leveraging Natural Killer Cell Innate Immunity against Hematologic Malignancies: From Stem Cell Transplant to Adoptive Transfer and Beyond

Numerous recent advancements in T-cell based immunotherapies have revolutionized the treatment of hematologic malignancies. In the race towards the first approved allogeneic cellular therapy product, there is growing interest in utilizing natural killer (NK) cells as a platform for off-the-shelf cellular therapies due to their scalable manufacturing potential, potent anti-tumor efficacy, and superior safety profile. Allogeneic NK cell therapies are now being actively explored in the setting of hematopoietic stem cell transplantation and adoptive transfer. Increasingly sophisticated gene editing techniques have permitted the engineering of chimeric antigen receptors, ectopic cytokine expression, and tumor recognition signals to improve the overall cytotoxicity of NK cell therapies. Furthermore, the enhancement of antibody-dependent cellular cytotoxicity has been achieved through the use of NK cell engagers and combination regimens with monoclonal antibodies that act synergistically with CD16-expressing NK cells. Finally, a greater understanding of NK cell biology and the mechanisms of resistance have allowed the preclinical development of NK checkpoint blockade and methods to modulate the tumor microenvironment, which have been evaluated in early phase trials. This review will discuss the recent clinical advancements in NK cell therapies in hematologic malignancies as well as promising avenues of future research.

Post-Transplant Lymphoproliferative Disease (PTLD) after Allogeneic Hematopoietic Stem Cell Transplantation: Biology and Treatment Options.

Post-transplant lymphoproliferative disease (PTLD) is a serious complication occurring as a consequence of immunosuppression in the setting of allogeneic hematopoietic stem cell transplantation (alloHSCT) or solid organ transplantation (SOT). The majority of PTLD arises from B-cells, and Epstein-Barr virus (EBV) infection is present in 60-80% of the cases, revealing the central role played by the latent infection in the pathogenesis of the disease. Therefore, EBV serological status is considered the most important risk factor associated with PTLDs, together with the depth of T-cell immunosuppression pre- and post-transplant. However, despite the advances in pathogenesis understanding and the introduction of novel treatment options, PTLD arising after alloHSCT remains a particularly challenging disease, and there is a need for consensus on how to treat rituximab-refractory cases. This review aims to explore the pathogenesis, risk factors, and treatment options of PTLD in the alloHSCT setting, finally focusing on adoptive immunotherapy options, namely EBV-specific cytotoxic T-lymphocytes (EBV-CTL) and chimeric antigen receptor T-cells (CAR T).