Unselected donor-derived hematopoietic stem cells boost for Chimeric Antigen Receptor T-cell associated hematotoxicity.

Hematological toxicity following Chimeric Antigen Receptor-T therapy in a patient with a prior allogeneic stem cell transplantation was resolved by the infusion of unselected donor-derived stem cell boost. Due to the donor's lymphocytes, the patient experienced a well-controlled flare-up of acute graft versus host disease.

Genetic mutations and leukapheresis in acute myeloid leukemia: is there a link?

Acute myeloid leukemia is the most common acute leukemia in adults and up to 20% of patients present with hyperleukocytosis at the onset of the disease. The therapeutic approach involves medical support, cytoreductive treatment, and/or leukapheresis. Despite WBC count greater than 100.000/µL, not all patients develop symptoms. To clarify the role of leukapheresis in the setting of hyperleukocytotic AML, we aimed to find associations between AML morphologic subtypes and molecular alterations on presence or absence of leukostasis symptoms (and hence therapeutic vs prophylactic leukapheresis) and clinical outcomes in the cohort of 41 patients at our single center who underwent leukapheresis for hyperleukocytotic AML. There was a trend for increased WBC count, 30-day mortality, M4-M5 AML subtypes, and number of leukapheresis procedures performed in symptomatic hyperleukocytotic pts. No molecular marker was significantly associated with presence or absence of leukostasis symptoms due to small sample size, though there was a trend for increased NPM1-mutated and NPM1 + FLT3-mutated AML in asymptomatic patients and a greater proportion of symptomatic patients who were negative for all assessed molecular alterations. In conclusion, leukapheresis combined with cytoreductive treatment represents a synergic and efficient approach in the management of hyperleukocytosis especially in symptomatic patients considering the higher mortality independently from the presence of specific clonal markers whose distribution among the two groups may result more considerable with a higher number of patients.

Peripheral Blood Allogeneic Stem Cell Mobilization: Can We Predict a Suboptimal Mobilization?

Allogeneic peripheral blood stem cells mobilization is now the basis of most stem cell transplants. In a very limited number of cases, mobilization is suboptimal leading to further collection procedures, to suboptimal cell doses infusion with delayed engraftment time, increased risks of transplant procedure and of related costs. To date we have no recognized and shared criteria for early estimating the probability of poor mobilization in healthy donors. We then analyzed allogeneic peripheral blood stem cell donations performed at the Fondazione Policlinico Universitario A.Gemelli IRCCS Hospital from January 2013 to December 2021 in order to identify premobilization factors associated with successful mobilization. The following data were collected: age, gender, weight, complete blood cell count at baseline, G-CSF dose, number of collection procedures, CD34+ cell count in peripheral blood on the first day of collection, CD34+ cell dose per kg body weight of recipient. Mobilization efficacy was defined according to the number of CD34+ cells in peripheral blood on day +5 of G-CSF administration. We classified donors as sub-optimal mobilizers or good mobilizers according to the achievement of the 50 CD34+ cell/µL threshold. We observed 30 suboptimal mobilizations in 158 allogeneic peripheral blood stem cell donations. Age and baseline white blood cell count were factors significantly associated with negative or positive impact on mobilization, respectively. We did not find significant differences in mobilization based on gender or G-CSF dose. Using cut-off values of 43 years and 5.5×109/L WBC count, we built a suboptimal mobilization score: donors who reach 2, 1 or 0 points have a 46%, 16% or 4% probability of suboptimal mobilization, respectively. Our model explains 26% of the variability of mobilization confirming that most of the mobilization magnitude depends on genetically determined factors; however, suboptimal mobilization score is a simple tool providing an early assessment of mobilization efficacy before G-CSF administration begins in order to support allogeneic stem cells selection, mobilization and collection. Through a systematic review, we looked for confirmation of our findings. According to the published articles, all the variables we included in our model are confirmed to be strongly related to the success of mobilization. We believe that score system approach could be applied in clinical practice to assess the risk of mobilization failure at baseline allowing for a priori intervention.

Managing leukapheresis in adult and pediatric patients eligible for chimeric antigen receptor T-cell therapy: suggestions from an Italian Expert Panel.

Chimeric antigen receptor (CAR) T-cell therapy relies on T cells engineered to target specific tumor antigens such as CD-19 in B-cell malignancies. In this setting, the commercially available products have offered a potential long-term cure for both pediatric and adult patients. Yet manufacturing CAR T cells is a cumbersome, multistep process, the success of which strictly depends on the characteristics of the starting material, i.e., lymphocyte collection yield and composition. These, in turn, might be affected by patient factors such as age, performance status, comorbidities, and previous therapies. Ideally, CAR T-cell therapies are a one-off treatment; therefore, optimization and the possible standardization of the leukapheresis procedure is critical, also in view of the novel CAR T cells currently under investigation for hematological malignancies and solid tumors. The most recent Best Practice recommendations for the management of children and adults undergoing CAR T-cell therapy provide a comprehensive guide to their use. However, their application in local practice is not straightforward and some grey areas remain. An Italian Expert Panel of apheresis specialists and hematologists from the centers authorized to administer CAR T-cell therapy took part in a detailed discussion on the following: 1) pre-apheresis patient evaluation; 2) management of the leukapheresis procedure, also in special situations represented by low lymphocyte count, peripheral blastosis, pediatric population <25 kg, and the COVID-19 outbreak; and 3) release and cryopreservation of the apheresis unit. This article presents some of the important challenges that must be faced to optimize the leukapheresis procedure and offers suggestions as to how to improve it, some of which are specific to the Italian setting.

Successful stem cell collection for atypical teratoid rhabdoid tumor in an extremely low-body weight child: A case report.

The use of peripheral blood hematopoietic stem cells for bone marrow reconstitution after myeloablative therapy is well established in children with malignant disorders. However, the peripheral blood hematopoietic stem cells collection in very low-body weight (≤10 kg) children remains a significant challenge because of technical and clinical issues. A male newborn affected by atypical teratoid rhabdoid tumor, diagnosed prenatally, received two cycles of chemotherapy following surgical resection. After an interdisciplinary discussion, it was decided to intensify the treatment with high-dose chemotherapy followed by autologous stem cell transplantation. After 7 days of G-CSF administration the patient underwent hematopoietic progenitor cells-apheresis collection. The procedure was performed in the pediatric intensive care unit, using two central venous catheters and Spectra Optia device. The cell collection procedure was completed in 200 min, during which time 3.9 total blood volumes were processed. During apheresis we did not observe electrolyte alterations. No adverse events were recorded during or immediately following the cell collection procedure. Our report describes the feasibility of performing large volume leukapheresis without complications in an extremely low-body weight patient weighing 4.5 kg using the Spectra Optia apheresis device. No catheter-related problems occurred, and apheresis was completed without any adverse event. In conclusion, we believe that very low-body weight pediatric patients need a multidisciplinary approach to manage central venous access, hemodynamic monitoring, cell collection, prevention of metabolic complications to improve safety, feasibility, and efficiency of stem cell collection procedures.

Day -1 CD34+ Cells and Platelet Count Predict the Number of Apheresis in Poor-Mobilizer Patients Rescued by Plerixafor.

Plerixafor is widely used as up-front treatment with G-CSF to enhance peripheral blood hematopoietic stem cell output in patients failing previous mobilizations. Less frequently, plerixafor is used to rescue an unsatisfactory mobilization following chemotherapy (CT) and G-CSF. This study investigates if pre-collection factors affect the CD34+ cell harvest in chemotherapy and G-CSF mobilizations rescued by plerixafor. Clinical and hematological data relative to patients, mobilization, and apheresis products were retrospectively examined. The outcome was completing a target cell dose ≥ 2 × 106 CD34+ cells/kg at first apheresis. The effect exerted on the outcome by patient- and disease-related factors was investigated by univariate and multivariate logistic regression analysis. The analysis included data from 42 patients affected by hematological (39 patients) and non-hematological malignancies (three patients). Twenty-nine patients (69%) attained the target cell dose at first apheresis. Twelve out of the remaining 13 patients received an additional plerixafor administration, and all accomplished the transplant dose at a second apheresis procedure. Day -1 CD34+ PB count (OR1.46, 95% CI 1.1-1.9, p = 0.008) and platelet count (OR1.0, 95% CI 1.0-1.0, p = 0.033) predicted the achievement of the target dose at first apheresis, independently of pre-mobilization CT, radiation therapy, and disease status at mobilization. At ROC curve analysis, the best cut-off value predicting the successful collection at first apheresis was 7.5/µL for Day -1 CD34+ cell count (AUC 0.830, 0.69 sensitivity, and 0.92 specificity) and 75 × 109/L for Day -1 platelet count (AUC = 0.736, 0.65 sensitivity and 0.85 specificity). In conclusion, on-demand plerixafor rescue allows a successful stem cell collection, irrespectively of disease type and status, prior CT lines, and radiation exposure. Pre-apheresis CD34+ cells and platelet count predict the need for one or two aphereses.

Midline catheters for extracorporeal photopheresis in hematological patients.

INTRODUCTION: Peripheral venous access for extracorporeal photopheresis (ECP) may be difficult in graft versus host disease (GVHD) patients, because of previous intravenous therapies and multiple peripheral cannulations; in this population of patients, ultrasound guided midline catheters may be an alternative option to central venous access. METHODS: In this single-center, prospective preliminary study, we enrolled all consecutive patients with a diagnosis of GVHD and candidate to ECP, over a period of 10 months. We used inserted power injectable, non-valved, polyurethane, 20-25 cm single lumen midline catheters (MC). RESULTS: Sixty-nine ECP procedures were carried out in six patients, using single-lumen MCs for outflow (5Fr in 74% and 4Fr in 26% of cases). For inflow, we used 5Fr or 4Fr MCs, or central venous access devices previously placed for other clinical reasons. There were no catheter-related complications during the entire period of ECP treatment. Mean outflow was significantly higher for 5Fr than for 4Fr MCs (35.8 ± 7.3 vs 29.2 ± 7.8 ml/min; p = 0.0008) and the procedure time was significantly shorter (92.9 ± 9.2 vs 108 ± 13.2 min; p < 0.0001). CONCLUSION: In GVHD patients, ECP can be performed efficiently and safely using single lumen polyurethane power injectable MCs. The best results are obtained with 5Fr rather than with 4Fr catheters. This strategy of venous access should be implemented in DIVA patients requiring ECP treatments, and probably also in other types of apheresis.

Day +60 WT1 assessment on CD34 selected bone marrow better predicts relapse and mortality after allogeneic stem cell transplantation in acute myeloid leukemia patients.

The aim of this study was to evaluate the role of WT1 expression after allogeneic stem cell transplantation (alloHSCT) in patients with acute myeloid leukemia (AML). We studied WT1 expression in bone marrow cells from 50 patients in complete remission on day +60 after transplant. WT1 was assessed on unfractionated bone marrow mononuclear cells (MNC) and on CD34+ selected cells (CD34+). A ROC curve analysis identified 800 WT1 copies on CD34+ selected cells, as the best cut-off predicting relapse (AUC 0.842, p=0.0006, 85.7% sensitivity and 81.6% specificity) and 100 copies in MNC (AUC 0.819, p=0.007, 83.3% sensitivity and 88.2% specificity). Using the 800 WT1 copy cut off in CD34+ cells, the 2 year cumulative incidence of relapse was 12% vs 38% (p=0.005), and 2 year survival 88% vs 55% (p=0.02). Using the 100 WT1 copy cut off in unfractionated MNC, the 2 year cumulative incidence of relapse 13% vs 44% (p=0.01) and the 2 year survival 88% vs 55% (p=0.08). In a multivariate Cox analysis WT1 expression in CD34 cells proved to highly predictive of relapse (p=0.004); also WT1 expression on unfractionated cells predicted relapse (p=0.03). In conclusion, day-60 WT1 expression after allogeneic HSCT is a significant predictor of relapse, particularly when tested on CD34+ selected bone marrow cells.

Successful "on-demand" plerixafor for autologous peripheral blood stem-cells transplantation for relapsed/refractory germ cell tumors.

BACKGROUND: Germ cell tumors represent, among solid cancers, a potentially curable disease even if up to 20% to 30% of patients (pts) relapse after first-line treatment especially considering intermediate and poor prognosis groups. In this scenario, patients are candidates for high-dose chemotherapy and autologous stem-cells transplantation as second-line treatment even though stem-cells mobilization potential can be affected by several cycles and regimens of chemotherapy. To date, plerixafor is authorized in poor mobilizer adult pts diagnosed with lymphoma or multiple myeloma and in pediatric solid tumors or lymphoma. Therefore, the use of plerixafor in adult pts with relapsing/refractory GCT is still off label. MATERIALS AND METHODS: In our study, we describe mobilization and collection of peripheral blood stem cells for 10 pts with germ cell tumors. Six patients underwent plerixafor administration since classified as poor mobilizers based on WBC count (>5.000/µL) and CD34+ cell count (<15/µL) the day before apheresis procedure. RESULTS: On the first day of apheresis, plerixafor administration in poor mobilizers made possible a remarkable boost of CD34+ cells in such a way to overlap that of good mobilizers' (32/µL vs 35/µL, respectively, P > .05). CONCLUSION: Therefore, in our experience, plerixafor made a good fraction of poor mobilizer patients eligible for mobilization and collection and able to undergo the predicted autologous stem-cells transplantation; thus, the lack of access to the use of plerixafor in this setting of patients risks jeopardizing an effective treatment, especially in case of poor prognosis.

Efficacy and Tolerability of First Line Arsenic Trioxide in Combination With All-Trans Retinoic Acid in Patients With Acute Promyelocytic Leukemia: Real Life Experience.

Acute promyelocytic leukemia is a variant of acute myeloid leukemia characterized by t(15;17) and PML/RAR alfa fusion gene. The discovery of the molecular pathogenesis has led to entitle all-trans retinoic acid (ATRA) as the first targeted therapy for acute leukemia. It is usually associated to anthracycline-based chemotherapy with high response rates, but potential long-term sequelae including therapy-related malignancies have been observed. Arsenic trioxide (ATO) was added to obviate these complications and investigational trials aimed to a new strategy with the incorporation of arsenic trioxide (ATO) into initial therapy instead of chemotherapy in selected patients. ATRA plus ATO without chemotherapy was the first attempt to treat low and intermediate-risk patients with APL. Our study aims to describe a monocentric cohort of patients with newly diagnosed APL effectively treated with ATO plus ATRA underlying its efficacy together with the high grade of tolerability of this association. From January 2009 to December 2019 23 APL patients were diagnosed and treated with ATO plus ATRA regimen: 14 males and 9 females patients with a median age of 45 years (range 18-72), for the majority intermediate risk (15 patients, 65%). The treatment was well tolerated and all patients achieved molecular remission after a median time of 3 months (range 1-6 months). All patients proceeded to consolidation phase as outpatients, they maintained complete molecular response at a median time of 44 months (range 15-127) except for 1 patient. All but one patient are alive and in response at a median follow-up of 48 months (range 9-141) without late effects. ATO plus ATRA regimen shows advantages in comparison to chemotherapy; in fact it allowed to treat patients in which chemotherapy could even not be applicable and it did not show secondary hematological diseases. The association of ATO to ATRA as chemo-free regimen enabled to treat APL even without chemotherapy.

Inline and offline extracorporeal photopheresis: Device performance, cell yields and clinical response.

BACKGROUND: Extracorporeal photopheresis (ECP) is an effective treatment for graft-vs-host-disease (GvHD). Photopheresis can be performed in offline or inline method. The first uses a conventional cell separator for collection of mononuclear-cells that are photoactivated by a separate device and manually reinfused; the second one involves a dedicated device performing the entire procedure (collection, photoactivation and reinfusion). STUDY DESIGN AND METHODS: The objective was to compare the two methods and cell product features to highlight key process, devices performance, and to evaluate ECP clinical response. Patients developing steroid-resistant GvHD underwent ECP as second-line treatment using either inline (Therakos CellEx) or offline system (Terumo BCT Spectra or Optia and UVA PIT system). Data about patients' features, pre-apheresis blood-count, cell product characteristics and clinical response were collected for analysis. RESULTS: We evaluated 494 procedures performed on 28 patients from April 2018 to March 2019. The offline procedure allows to achieve greater cell yield, it is characterized by larger processed blood volume, longer runtime, and higher ACD consumption. The inline procedure shows shorter runtime, high mononuclear-cells percentage and low percentage of granulocytes in cell product. We observed a significant difference in cell yields between inline and offline system; furthermore we did not find a significant relationship between cell dose and clinical response. CONCLUSION: Inline ECP is fast, highly automated and productive, making it particularly suitable for ECP treatments. Offline ECP collects high cell yields implying longer procedure and greater operator intervention. Our study did not find a significant relationship between cell dose and GVHD response.

Fibrin sealant reduces need for transfusions after hip hemiarthroplasty for femoral neck fractures.

INTRODUCTION: Every year more than 300,000 proximal femur fractures are diagnosed. Their number will double within 30 years. In femoral neck fractures treated with hip hemiarthroplasty 90-days mortality is 29.5-51.6%. Haemorrhage is one amongst other complications that is associated with increasing postoperative mortality. Transfusion rate in these patients ranges from 25.7% to 39%. Blood transfusions expose to complications. Fibrin sealants are useful in reducing perioperative need for transfusions, total blood loss, blood loss from drainage. The aim of this study is to assess whether the use of a fibrin sealant during hip hemiarthroplasty implant reduces the need for transfusion. PATIENT AND METHODS: All patients admitted with a proximal femur fracture from September 2018 to May 2019 were reviewed. Inclusion criteria were: femoral neck fracture AO 31B2-3, hip hemiarthroplasty. Exclusion criteria were: previous surgery on the affected hip, coagulation disorders, hematopoietic disorders. Patients were divided in fibrin sealant group and control group. All patients underwent partial hip replacement through a posterolateral approach. 4 ml of fibrin sealant (EVICEL, Omrix Biopharmaceuticals, Diegem, Belgium) were sprayed on the soft tissues of patients included in the fibrin sealant group. Primary outcome of our study was need for perioperative transfusion. Secondary outcomes were: mean red blood cell transfused volume, variations in haematocrit and haemoglobin and total blood volume loss. RESULTS: Eighty-one consecutive patients were enrolled. EVICEL was used on 19 patients, standard haemostatic care on 62 patients. Two patients were transfused in the fibrin sealant group, 22 in the control group (p 0,0371). Mean transfused volume was 21,05 ml in the fibrin sealant group and 116,16 ml in the control group (p 0,0017). No significant difference could be found in haematocrit and haemoglobin variation and total blood loss. DISCUSSION: A reduction in transfusional need with the use of fibrin sealants was reported in studies on total hip arthroplasty and was confirmed by our study. CONCLUSION: EVICEL reduces need for transfusion in patients undergoing hip hemiarthroplasty for a femoral neck fracture. It must be held among the options when a stricter control on transfusional requirement is needed.

Inline extracorporeal photopheresis: evaluation of cell collection efficiency.

BACKGROUND: Extracorporeal photopheresis (ECP) therapy has proved to be an effective and safe treatment for graft-versus-host-disease (GvHD), an important complication after hematopoietic stem cell transplantation. In 2016, we acquired Therakos CellEx, a dedicated inline ECP device to accomplish a significant increase in ECP activity. In literature, we found few data reporting CellEx performance evaluated in terms of collection efficiency to qualify the device. Hence, we decided to collect and analyze our data in order to build a reference in terms of expected results of the procedure. Here we report our data of ECP performed using CellEx in a 12-month period focusing on collection efficiency assessment, as well as procedural and apheretic product characteristics. STUDY DESIGN AND METHODS: We collected data of patients undergoing ECP from April 2018 to March 2019 using CellEx in order to evaluate collection efficiency. RESULTS: Between April 2018 and March 2019 we treated 28 adult patients affected by GvHD performing 319 ECP using CellEx. CellEx mononuclear cell product was characterized by high mononuclear cell percentage and low percentage of granulocytes, resulting particularly suitable for ECP treatments. Median collection efficiency for total nucleated cells and for mononuclear cells was 31.2% and 62.3%, respectively. CONCLUSION: Collection efficiency of CellEx was comparable to that usually obtained by cell separators designed for cell collection and was comparable to that of offline systems. Our results provide a detailed performance evaluation for inline ECP system users.

Peripheral Blood Hemopoietic Stem Cell Mobilization Regimens in POEMS Syndrome: A Retrospective Study at 2 Hematologic Italian Centers.

Autologous peripheral blood stem cell transplantation should be considered first-line therapy in young patients with POEMS. The best protocol to collect peripheral blood stem cells remains to be defined, because of the disease rarity and the heterogeneity of published case series. We collected clinical and laboratory data from 25 patients undergoing mobilization, of whom 11 were mobilized using cyclophosphamide (CY) followed by granulocyte colony-stimulating factor (G-CSF) and 14 patients using G-CSF. The incidence of poor mobilization was low and not statistically different between the 2 groups. Both schemes (CY plus G-CSF versus G-CSF alone) were able to harvest a sufficient CD34+ cell dose.

Predicting failure of hematopoietic stem cell mobilization before it starts: the predicted poor mobilizer (pPM) score.

Predicting mobilization failure before it starts may enable patient-tailored strategies. Although consensus criteria for predicted PM (pPM) are available, their predictive performance has never been measured on real data. We retrospectively collected and analyzed 1318 mobilization procedures performed for MM and lymphoma patients in the plerixafor era. In our sample, 180/1318 (13.7%) were PM. The score resulting from published pPM criteria had sufficient performance for predicting PM, as measured by AUC (0.67, 95%CI: 0.63-0.72). We developed a new prediction model from multivariate analysis whose score (pPM-score) resulted in better AUC (0.80, 95%CI: 0.76-0.84, p < 0001). pPM-score included as risk factors: increasing age, diagnosis of NHL, positive bone marrow biopsy or cytopenias before mobilization, previous mobilization failure, priming strategy with G-CSF alone, or without upfront plerixafor. A simplified version of pPM-score was categorized using a cut-off to maximize positive likelihood ratio (15.7, 95%CI: 9.9-24.8); specificity was 98% (95%CI: 97-98.7%), sensitivity 31.7% (95%CI: 24.9-39%); positive predictive value in our sample was 71.3% (95%CI: 60-80.8%). Simplified pPM-score can "rule in" patients at very high risk for PM before starting mobilization, allowing changes in clinical management, such as choice of alternative priming strategies, to avoid highly likely mobilization failure.