Posttransplant Autoimmune Hemolytic Anemia with Anti-D Specificity Successfully Treated with Daratumumab: A Case Report.

Introduction: Autoimmune hemolytic anemia (AIHA) occurs in 0.7-5.6% of patients undergoing hematopoietic stem cell transplantation, especially from unrelated or haploidentical donor or after lympho-depleted transplant; the majority of cases are represented by warm AIHA, occurring in a full donor chimerism setting. Standard treatments (corticosteroids, intravenous immunoglobulin, splenectomy, rituximab, cyclophosphamide, plasma exchange) lead to lower response rates than those reported in primary AIHA. Daratumumab use has been proposed in many autoimmune conditions (immune thrombocytopenic purpura, aplastic anemia, thrombotic thrombocytopenic purpura, systemic lupus erythematosus, multiple sclerosis), but only few reports have been published on its use for post-HSCT AIHA, mainly in pediatric patients. Case Presentation: We report the successful use of daratumumab in a 68-year-old patient, suffering from post-HSCT AIHA. Five months after Rh-mismatched HSCT, the patient was diagnosed with anti-D AIHA. After first-line treatment (oral prednisone, rituximab, and plasma exchange) failure, being still transfusion-dependent with symptomatic anemia, he underwent treatment with daratumumab, achieving both clinical and laboratory responses. Discussion: Daratumumab may represent a safe and effective alternative to conventional immunosuppressive therapy, and it deserves further investigations.

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

Introduction: 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. Methods: 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. Results: 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. Discussion: 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.

Deep Molecular Response Rate in Chronic Phase Chronic Myeloid Leukemia: Eligibility to Discontinuation Related to Time to Response and Different Frontline TKI in the Experience of the Gimema Labnet CML National Network.

BACKGROUND: In the last decade, TKIs improved the overall survival (OS) of chronic myeloid leukemia (CML) patients who achieved a deep and sustained molecular response (DMR, defined as stable MR4 and MR4.5). Those patients may attempt therapy discontinuation. In our analysis, we report the differences in eligibility criteria due to time of response and different TKI used as frontline treatment analyzed in a large cohort of CP-CML patients. METHODS: Data were exported by LabNet CML, a network founded by GIMEMA in 2014. The network standardized and harmonized the molecular methodology among 51 laboratories distributed all over Italy for the diagnosis and molecular residual disease (MRD) monitoring. RESULTS: Out of 1777 patients analyzed, 774 had all evaluable timepoints (3, 6, and 12 months). At 3 months, 40 patients obtained ≥MR4: of them 14 (3.6%) with imatinib, 8 (5.8%) with dasatinib, and 18 (7.4%) with nilotinib (P = .093); at 6 months, 146 patients were in MR4: 42 (11%) with imatinib, 38 (28%) with dasatinib, and 66 (27%) with nilotinib (P < .001). At 12 months, 231 patients achieved a DMR: 85 (22%) with imatinib, 55 (40%) with dasatinib and 91 (38%) with nilotinib (P < .001). Achieving at least ≥MR2 at 3 months, was predictive of a DMR at any timepoint of observation: with imatinib 67% versus 30% of patients with 2 years was significant for patients who at 3 months had ≥MR2 (18% vs. 9.9% of pts with

A Multicenter Real-life Prospective Study of Axicabtagene Ciloleucel versus Tisagenlecleucel Toxicity and Outcomes in Large B-cell Lymphomas.

This real-world prospective observational study across 21 Italian centers (CART-SIE) compares axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel) outcomes in 485 patients with relapsed/refractory large B-cell lymphoma with baseline characteristics matched by stabilized inverse propensity score weighting. Axi-cel versus tisa-cel had higher all-grade cytokine release syndrome (78.6% vs. 89.3%, P = 0.0017) and neurotoxicity (9.9% vs. 32.2%, P < 0.0001) but also superior progression-free survival (PFS) at 1 year (46.5% vs. 34.1%, P = 0.0009). Even among patients who failed bridging therapy, axi-cel PFS was superior to tisa-cel (37.5% vs. 22.7%, P = 0.0059). Differences in overall survival and high-grade immune toxicities were not significant. The CAR-HEMATOTOX score not only predicted hematologic toxicity but also 1-year survival outcomes (51.5% in CAR-HEMATOTOX high vs. 77.2% in CAR-HEMATOTOX low, P < 0.0001). Twenty patients developed second primary malignancies, including two cases of T-cell neoplasms. These findings enable more informed selection of anti-CD19 CAR T-cell therapy, balancing bridging, safety, and efficacy considerations for individual patients. Significance: The findings of this study on 485 patients with relapsed/refractory large B-cell lymphoma treated with commercial axi-cel and tisa-cel indicate axi-cel's superior PFS after propensity score weighting. The predictive utility of CAR-HEMATOTOX in assessing not only toxicity but also outcomes across both CAR T-cell products may guide future risk-stratified management strategies.

Pure red cell aplasia among ABO mismatched hematopoietic stem cell transplant recipients: a 13-years retrospective study and literature review.

Background: Pure red cell aplasia (PRCA) is a possible complication after allogeneic hematopoietic stem cell transplantation (HSCT) with major ABO incompatibility. Patients experience delayed engraftment of the erythroid series, with prolonged transfusion-dependent anemia and iron overload. Methods: We performed a revision of the most recent literature about post-HSCT PRCA treatment procedures. Moreover, we conducted a retrospective study, over the last 13-years, which included all consecutive major ABO mismatched HSCT performed in our unit, with the aim to assess PRCA incidence, risk factors, and response to different treatments. Overall, 194 patients received a major ABO mismatched transplant from 2010 to 2022. For each patient, data about demographic and transplant characteristics, engraftment, blood transfusion, and possible treatment received were collected. Results: The literature review returned 23 eligible papers on PRCA treatment, with high success rate using plasma-exchange (PEX) and immunoadsorption procedures, daratumumab, and eltrombopag. Our study identified a total of 24 cases of PRCA. Among risk factors for PRCA development, we have found older recipient age (p=0.01), high pre-HSCT IgG and IgM IHA titer (p<0.0001), major rather than bidirectional ABO incompatibility (p=0.02), low T CD8 lymphocyte count in the graft (p=0.006), relative donor (p=0.02) and bone marrow as stem cell source (p=0.002). However, multivariate analysis confirmed only pre-HSCT IgG IHA titer as the unique risk factor for PRCA occurrence. The optimal cut-off value of pre-HSCT IgG IHA for PRCA development, resulted to be 1/64, with a 100% sensitivity and 68.8% specificity (p<0.0001). All patients with PRCA had received rhEPO and transfusion support and 20 patients received additional treatments like PEX, rituximab, and more recently daratumumab. Comprehensively, PEX and rituximab obtained a response in half of the cases, at a variable time, while the few cases of patients we treated with daratumumab suggest promising results. The overall response rate in our cohort was 75%, with significantly better survival (94.4% vs. 16.7%) and lower transplant-related mortality (6.3% vs. 80%) for PRCA responders. Conclusions: Standardized guidelines on when and how to treat PRCA are necessary because the current treatment is controversial among centers.

Real World Use of Tixagevimab/Cilgavimab Pre-Exposure Prophylaxis of COVID-19 in Immunocompromised Individuals: Data from the OCTOPUS Study.

Objective. We aimed to report the real-world use and outcomes over time in immunocompromised individuals receiving tixagevimab/cilgavimab (T/C) pre-exposure prophylaxis (PrEP). Methods. This observational study included participants who received T/C PrEP, categorized into three groups: (i) No COVID-19 (NoC), i.e., participants who never had COVID-19; (ii) Hybrids (H), i.e., participants who had COVID-19 before PrEP; and (iii) Break-through Infections (BTIs), i.e., participants who had COVID-19 after PrEP. The study measured several immune markers at the administration of T/C (T0) at 3 (T1), 6 (T2), and 9 (T3) months afterward. These markers included: anti-receptor-binding domain (RBD) IgG antibodies; BA.5-neutralizing antibodies (nAbs); mucosal IgG; and T cell immunity. The incidence rate ratios for BTIs were analyzed using a Poisson regression model. Results. A total of 231 participants with a median age of 63 years (IQR 54.0-73.0). were included. Among these, 84% had hematological diseases and received a median of three vaccine doses. N = 72 participants belonged to the NoC group, N = 103 to the H group, and n = 56 to the BTI group (24%), with most BTIs being mild/moderate. The incidence rate (IR) of BTIs was 4.2 per 100 patient-months (95% CI 3.2-5.4), with no associated risk factors identified. There was a significant increase in anti-RBD IgG levels 3 months after the T/C administration in all groups, followed by a decline at 6 months, whereas at the same time points, geometric mean titers (GMTs) of anti-BA.5 nAbs were low for all groups and were around or below the detection threshold. No significant changes were observed in IFN-γ levels. The mucosal immune response was observed only 3 months after the PrEP administration. Conclusion. We provided a real-world experience model on the clinical efficacy of T/C PrEP in preventing severe COVID-19 during the Omicron wave through a comprehensive virological and immunological study. While waiting for the arrival of new monoclonal antibodies that can effectively neutralize the most recent variants, T/C PrEP remains the only viable strategy in the available armamentarium today to prevent COVID-19 complications in an extremely fragile population with suboptimal immune responses to COVID-19 vaccines.

Coagulopathy in CAR-T: Critical concern or mere blip?

Despite Peng and colleagues providing an extensive review of the clinical and laboratory aspects of CAR-T-associated coagulopathy, the current literature often lacks specificity in nomenclature and gradings, and the clinical implications of coagulopathy may remain unclear. Clear recommendations on stratification and prophylaxis are still required to standardize the clinical approach to this topic. Commentary on: Peng et al. Coagulation abnormalities associated with CAR-T therapy in hematological malignancies: A review. Br J Haematol 2024;205:420-428.

CAR-T from cord blood in a patient with Ph+ acute lymphoblastic leukemia relapsing after hematopoietic stem cell transplantation.

While there is intense interest in the production of allogeneic CAR-T cells from umbilical cord units, little is known about the reactivity and persistence of CAR-T cells of umbilical origin. We report the case of a patient at our hematological center with multiple relapsing Ph+ B-ALL, notably a Blinatunomab non-responder, who underwent therapy with Brexucabtagene Autoleucel following relapse on Ponatinib post-allogeneic hematopoietic stem cell transplantation. The patient achieved a rapid CAR-T expansion and durable remission presenting in good clinical conditions 6 months post-CAR-T infusion, without manifestations of graft-versus-host disease. The case report provides insight into the reactivity and persistence of CAR-T cells of umbilical origin, confirming the potential promise of allogeneic umbilical cord-derived CAR-T cells.

Inflammation and acute cardiotoxicity in adult hematological patients treated with CAR-T cells: results from a pilot proof-of-concept study.

AIMS: Chimeric Antigen Receptor-T (CAR-T) cell infusion is a rapidly evolving antitumor therapy; however, cardiovascular (CV) complications, likely associated with cytokine release syndrome (CRS) and systemic inflammation, have been reported to occur. The CARdio-Tox study aimed at elucidating incidence and determinants of cardiotoxicity related to CAR-T cell therapy. METHODS: Patients with blood malignancies candidate to CAR-T cells were prospectively evaluated by echocardiography at baseline and 7 and 30 days after infusion. The study endpoints were i) incidence of cancer therapy-related cardiac dysfunction (CTRCD), CTRCD were also balanced for any grade CRS, but CTRCD occurred of Cardiology Guidelines on Cardio-Oncology (decrements of left ventricular ejection fraction (LVEF) or global longitudinal strain (GLS) and/or elevations of cardiac biomarkers (high sensitivity troponin I, natriuretic peptides) and ii), correlations of echocardiographic metrics with inflammatory biomarkers. RESULTS: Incidence of CTRCD was high at 7 days (59,3%), particularly in subjects with CRS. The integrated definition of CTRCD allowed the identification of the majority of cases (50%). Moreover, early LVEF and GLS decrements were inversely correlated with fibrinogen and interleukin-2 receptor levels (p always ≤ 0.01). CONCLUSIONS: There is a high incidence of early CTRCD in patients treated with CAR-T cells, and a link between CTRCD and inflammation can be demonstrated. Dedicated patient monitoring protocols are advised.

Unlocking Predictive Power: Quantitative Assessment of CAR-T Expansion with Digital Droplet Polymerase Chain Reaction (ddPCR).

Flow cytometry (FCM) and quantitative PCR (qPCR) are conventional methods for assessing CAR-T expansion, while digital droplet PCR (ddPCR) is emerging as a promising alternative. We monitored CAR-T transcript expansion in 40 B-NHL patients post-infusion of CAR-T products (axi-cel; tisa-cel; and brexu-cel) with both His-Tag FCM and ddPCR techniques. Sensitivity and predictive capacity for efficacy and safety outcomes of ddPCR were analyzed and compared with FCM. A significant correlation between CAR-T counts determined by FCM and CAR transcripts assessed by ddPCR (p < 0.001) was observed. FCM revealed median CD3+CAR+ cell counts at 7, 14, and 30 days post-infusion with no significant differences. In contrast, ddPCR-measured median copies of CAR-T transcripts demonstrated significant lower copy numbers in tisa-cel recipients compared to the other products at day 7 and day 14. Patients with a peak of CAR transcripts at day 7 exceeding 5000 copies/microg gDNA, termed "good CAR-T expanders", were more likely to achieve a favorable response at 3 months (HR 10.79, 95% CI 1.16-100.42, p = 0.036). Good CAR-T expanders showed superior progression-free survival at 3, 6, and 12 months compared to poor CAR-T expanders (p = 0.088). Those reaching a peak higher than 5000 copies/microg gDNA were more likely to experience severe CRS and ICANS. DdPCR proves to be a practical method for monitoring CAR-T expansion, providing quantitative information that better predicts both treatment outcomes and toxicity.

Risk factors for hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation in a letermovir-exposed CMV-free population receiving PTCy.

Hemorrhagic cystitis (HC) is a highly impacting complication in allogeneic hematopoietic stem cell transplantation (HSCT), occurring in 12%-37% of patients. The impact of transplant- and patient-specific variables has been described, with a possible role for JCV and BKV, which may be cooperating with cytomegalovirus (CMV). Here, we analyze 134 letermovir-exposed, CMV-free patients, treated with the same cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis, describing risk factors for HC. The overall incidence of HC was 23%. Patients with HLA mismatched transplant, higher comorbidity score, and receiving three alkylating agents with TBF (thiotepa, busulfan, and fludarabine) conditioning regimen had a higher risk of HC in multivariate analysis (OR: 4.48, 6.32, and 1.32, respectively). A HC-score including male gender, TBF conditioning, and HLA-mismatch stratifies the risk of HC in the first 100 days after HSCT. The role of BKV and JCV was not highly impacting in those patients, suggesting a possible synergistic effect between CMV and JCV in causing HC. HC can be interpreted as the combination of patient-related factors, chemotherapy-related toxicities-especially due to alkylating agents-and immunological elements.

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.

Hematopoiesis and immune reconstitution after CD19 directed chimeric antigen receptor T-cells (CAR-T): A comprehensive review on incidence, risk factors and current management.

Impaired function of hematopoiesis after treatment with chimeric antigen T-cells (CAR-T) is a frequent finding and can interest a wide range of patients, regardless of age and underlying disease. Trilinear cytopenias, as well as hypogammaglobulinemia, B-cell aplasia, and T-cell impairment, can severely affect the infectious risk of CAR-T recipients, as well as their quality of life. In this review, we provide an overview of defects in hematopoiesis after CAR-T, starting with a summary of different definitions and thresholds. We then move to summarize the main pathogenetic mechanisms of cytopenias, and we offer insight into cytomorphological aspects, the role of clonal hematopoiesis, and the risk of secondary myeloid malignancies. Subsequently, we expose the major findings and reports on T-cell and B-cell quantitative and functional impairment after CAR-T. Finally, we provide an overview of current recommendations and leading experiences regarding the management of cytopenias and defective B- and T-cell function.

The CD4/CD8 ratio of infused CD19-CAR-T is a prognostic factor for efficacy and toxicity.

CD4+ and CD8+ chimeric antigen receptor T cells (CAR-T) play different roles in the in vivo anti-tumour response, but the role of the CD4+ /CD8+ ratio among infused CAR-T has not been clearly defined yet. We analysed leftovers from infused anti-CD19 CAR-T bags of 31 patients with aggressive B-cell lymphomas. The median ratio was 1.44, lower for brexu-cel compared to tisa-cel and axi-cel. The CAR+CD4+ /CD8+ ratio was influenced by lactate dehydrogenase levels at apheresis, not by age, previous treatments or the CD4+ /CD8+ ratio in peripheral blood. Patients with a response at 3 months after CAR-T (M3) had a lower CAR+CD4+ /CD8+ ratio in the infused products compared to non-responders (ratio 0.74 vs. 2.47, p = 0.011). A CAR+CD4+ /CD8+ ratio higher than the cut point of 1.12 was associated with an increased risk of treatment failure at M3 (OR 23.3, p = 0.012) and M6 (OR 10, p = 0.028). The median 6-month PFS was 76% for patients with a ratio lower than 1.12% vs. 31% for the others. The prognostic role of the CAR+CD4+ /CD8+ ratio was independent of the costimulatory domain (CD28 vs. 4-1BB) of the product (OR 16.41, p = 0.041). Our data indicate a crucial role for CD8+ CAR-T and the CAR+CD4+ /CD8+ ratio in predicting CAR-T efficacy.

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.