ADAMTS13 recovery in acute thrombotic thrombocytopenic purpura after caplacizumab therapy.

ABSTRACT: Caplacizumab prevents the interaction between von Willebrand factor and platelets and is used to treat immune thrombotic thrombocytopenic purpura (iTTP). Its administration has been associated with a delay in ADAMTS13 activity restoration after plasma exchange (PEX) suspension. We analyzed the outcomes of 113 iTTP episodes, 75 of which were treated with caplacizumab, in 108 patients from the Spanish Registry of Thrombotic Thrombocytopenic Purpura. Caplacizumab shortened the time to platelet count normalization and reduced PEX requirement, exacerbations, and relapses. There was no difference in the time to achieve ADAMTS13 activity ≥20% after PEX end between caplacizumab-treated and nontreated episodes (median [interquartile range], 14.5 [7.7-27.2] vs 13.0 [8.0-29.0] days, P = .653). However, considering the 36 episodes in which caplacizumab was started ≤3 days after iTTP diagnosis, the time for ADAMTS13 restoration from PEX end was higher than in those episodes in which caplacizumab was started >3 days after iTTP diagnosis (20.0 [12.0-43.0] vs 11.0 [3.5-20.0] days, P = .003) or than in non-caplacizumab-treated episodes (P = .033). This finding could be related to a significantly shorter duration of PEX in early caplacizumab-treated episodes than in late caplacizumab-treated episodes (5.5 [4.0-9.0] vs 15.0 [11.0-21.5] days, P < .001) or non-caplacizumab-treated episodes (11.0 [6.0-26.0] days, P < .001). There were no differences in time to ADAMTS-13 restoration from PEX start (28.0 [17.2-47.5], 27.0 [19.0-37.5] and 29.5 [15.2-45.0] days in early caplacizumab-treated, late caplacizumab-treated and non-caplacizumab-treated episodes). Early administered caplacizumab does not prevent the requirement for immunosuppression but has beneficial effects by shortening PEX requirement without major safety concerns.

Effectiveness of Caplacizumab Nanobody in Acquired Thrombotic Thrombocytopenic Purpura Refractory to Conventional Treatment.

Acquired thrombocytopenic thrombotic purpura (aTTP) is an autoantibody-mediated disease against the enzyme A Disintegrin and Metalloprotease domain with ThromboSpondin-1 type motif 13, which until now has been treated with plasma exchange (PEX) and corticosteroids. A 29-year-old female patient, who presented with aTTP in the context of pregnancy, has developed multiple relapses after treatment with PEX, corticosteroids, and rituximab. Recently, caplacizumab, a nanobody against von Willebrand factor, has been approved for the treatment of aTTP. In our patient, caplacizumab achieved better disease control, with a lower platelet count restoration time, days of PEX and hospitalization duration, as compared to standard therapy, reproducing the results of clinical trials. Caplacizumab represents a significant advance in the treatment of aTTP, especially in cases of recurrent relapses.

Acute hemolytic reaction by anti-Wra: Case report and review of the hemovigilance database of a tertiary care hospital.

Wra is the most common LIA in white population. The incidence of Wra antigen in Spanish population has been estimated to be 1 in 785 in blood donors, while anti-Wra was found in 2.7 % and 3.6 % of healthy donors and transfused patients respectively. Severe, even fatal hemolytic transfusion reactions and hemolytic disease of the newborn caused by anti-Wra have been reported. Since the reagent red blood cells used for antibody screening usually lack Wra antigen, the anti-Wra is not detected and hemolytic reaction could occur if transfusion is performed by type and screen approach. We report an acute hemolytic reaction due to anti-Wra in a patient with negative antibody screening. We have also reviewed the records of the hospital hemovigilance database in order to collect the previous hemolytic cases due to anti-Wra. During a 21-year period 461,539 red blood cell units have been transfused to 81,614 patients in our hospital. Alloimmnunization was detected in 3840 patients (0.83 %) and anti-Wra was detected in 22 patients (1/3709), 10 of whom had other alloantibodies, and only in 1 occasion (this case) has been implicated in mild hemolytic acute transfusion reaction. In our experience, the risk of fatal hemolytic reaction due to LIA in hospitals with blood services using the type and screen policy is extremely low.

Role of extracorporeal photopheresis in the management of children with graft-vs-host disease.

INTRODUCTION: Graft-vs-host disease (GVHD) is a frequent cause of morbidity and mortality in allogeneic stem cell transplants. Extracorporeal photopheresis (ECP) is one of the most accepted second-line treatments, but technical issues of ECP in children might be prohibitive. MATERIALS AND METHODS: Patients under 18 y of age with corticodependant or corticorefractory GVHD receiving ECP at our hospital were included in this retrospective study. ECP was performed with an in-line system (CellExTherakos) in 2013-2014 and with an off-line system (Spectra Optia) from 2015 onwards. Cumulative incidence curves were obtained to compare ECP efficacy among patients grouped by different baseline, apheresis, and disease characteristics. Significant variables on univariate analysis (Gray's test) were pooled into a multivariate analysis (Fine-Gray proportional hazard regression for competing events). RESULTS: A total of 701 ECP sessions were performed on 33 patients between October 2013 and December 2021. In total, 97% of the sessions could be executed. In 8% of the sessions an incident was detected, most of them mild and related to catheter dysfunction. With a median follow-up for alive patients of 33.6 mo (range, 8-95), the composite partial and complete response cumulative incidence was 70% (95% confidence interval, 51%-82%) and the median time to maximal response was 2.8 mo (range, 0.25-9.8). Significantly lower response ratios were found in patients with hepatic, gastrointestinal, acute, or severe GVHD. The only variable that influenced response on multivariate analysis was GVHD severity. DISCUSSION: ECP is feasible, safe, and effective for pediatric patients with corticorefractory or corticodependant GVHD, offering a less toxic and nonimmunosuppressive treatment option.

Adoptive transfer of ex vivo expanded SARS-CoV-2-specific cytotoxic lymphocytes: A viable strategy for COVID-19 immunosuppressed patients?

Cellular and humoral response to acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is on focus of research. We evaluate herein the feasibility of expanding virus-specific T cells (VST) against SARS-CoV-2 ex vivo through a standard protocol proven effective for other viruses. The experiment was performed in three different donors' scenarios: (a) SARS-CoV-2 asymptomatic infection/negative serology, (b) SARS-CoV-2 symptomatic infection/positive serology, and (c) no history of SARS-CoV-2 infection/negative serology. We were able to obtain an expanded VST product from donors 1 and 2 (1.6x and 1.8x increase of baseline VST count, respectively) consisting in CD3 + cells (80.3% and 62.7%, respectively) with CD4 + dominance (60% in both donors). Higher numbers of VST were obtained from the donor 2 as compared to donor 1. T-cell clonality test showed oligoclonal reproducible peaks on a polyclonal background for both donors. In contrast, VST could be neither expanded nor primed in a donor without evidence of prior infection. This proof-of-concept study supports the feasibility of expanding ex vivo SARS-CoV-2-specific VST from blood of convalescent donors. The results raise the question of whether the selection of seropositive donors may be a strategy to obtain cell lines enriched in their SARS-CoV-2-specificity for future adoptive transfer to immunosuppressed patients.

Incidence, diagnosis, and outcome of immune-mediated thrombotic thrombocytopenic purpura: A nationwide survey by the Spanish registry of thrombotic thrombocytopenic purpura.

BACKGROUND: Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare disease characterized by the presence of anti-ADAMTS13 autoantibodies. Achieving accurate information on incidence and customary disease management is important to provide appropriate diagnostic and therapeutic resources. The aim of this study was to determine the incidence and outcomes of iTTP in Spain. STUDY DESIGN AND METHODS: A cross-sectional survey was carried out among Spanish hospitals, focused on iTTP patients ≥16 years old attended between 2015 and 2017, and those at follow-up before that interval. Incidence, prevalence, mortality, refractoriness, exacerbations, treatment complications, relapses, and sequelae were estimated. RESULTS: Forty-two hospitals covering roughly 20 million inhabitants answered the survey and reported 203 episodes (138 newly-diagnosed and 65 relapses), of which 193 (95.1%) were treated. Incidence was 2.67 (95% CI 1.90-3.45) patients per million inhabitants per year and prevalence 21.44 (95% CI% 19.10-23.73) patients per million inhabitants. At diagnosis, ADAMTS13 activity and anti-ADAMTS13 autoantibody were measured in 97% and 84.3% of reported episodes, respectively. Fifteen patients (7.4%) died as a direct consequence of iTTP, 6 of them before receiving any iTTP-specific treatment. Thirty-one (16.1%) of the 193 treated episodes were refractory to plasma exchange and corticosteroids, and 51 (26.4%) suffered at least one exacerbation. CONCLUSION: iTTP incidence and prevalence were somewhat higher than those documented in neighboring countries. Together with data on treatments and outcomes, this information will allow us to better estimate what is needed to improve diagnosis and prognosis of iTTP patients in Spain.

Partial T Cell-Depleted Peripheral Blood Stem Cell Transplantation from HLA-Identical Sibling Donors for Patients with Severe Aplastic Anemia.

We analyzed the outcomes of 26 consecutive patients with acquired severe aplastic anemia (SAA) undergoing peripheral blood stem cell transplantation (PBSCT) with partial ex vivo T cell depletion with a targeted T cell dose from HLA-identical sibling donors. The median patient age was 37 years (range, 3 to 63 years). Four patients with uncontrolled pneumonia at the time of transplantation died, on days +1, +2, +21, and +26. All evaluable patients engrafted, with a median time to neutrophil recovery of 11 days (range, 10 to 14 days) and a median time to platelet recovery of 19 days (range, 8 to 53 days). Two patients had transient grade I acute graft-versus-host disease (GVHD) with skin involvement, but no patients developed grade II-IV acute GVHD. Two patients had mild skin chronic GVHD, and 1 patient had moderate chronic GVHD with ocular involvement. No relapse was observed after a median follow-up of 114 months (range, 4 to 233 months). The overall cumulative incidence of TRM at 10 years was 19%, whereas it was 5% for those with a Karnofsky Performance Status (KPS) score >60 at the time of transplantation. Disease-free survival, overall survival, and GVHD and relapse-free survival at 10 years were 81%, 81%, and 80%, respectively, for all patients and 95%, 95%, and 90%, respectively, for patients with a KPS score >60 at transplantation. Our data indicate that PBSCT with partial ex vivo T cell-depleted targeted cell dose grafts from an HLA-identical sibling donor is a feasible, safe, and effective approach to reduce GVHD and cure patients with SAA.

Molecular profiling refines minimal residual disease-based prognostic assessment in adults with Philadelphia chromosome-negative B-cell precursor acute lymphoblastic leukemia.

Minimal residual disease (MRD) assessment is an essential tool in contemporary acute lymphoblastic leukemia (ALL) protocols, being used for therapeutic decisions such as hematopoietic stem cell transplantation in high-risk patients. However, a significant proportion of adult ALL patients with negative MRD still relapse suggesting that other factors (ie, molecular alterations) must be considered in order to identify those patients with high risk of disease progression. We have identified partial IKZF1 gene deletions and CDKN2A/B deletions as markers of disease recurrence and poor survival in a series of uniformly treated adolescent and adult Philadelphia chromosome-negative B-cell progenitor ALL patients treated according to the Programa Español de Tratamientos en Hematología protocols. Importantly, CDKN2A/B deletions showed independent significance of MRD at the end of induction, which points out the need for treatment intensification in these patients despite being MRD-negative after induction therapy.

Therapeutic plasma exchange: Review of current indications.

Therapeutic plasma exchange (TPE) is the extracorporeal technique performed in an apheresis device were patient's plasma is separated from whole blood and removed, while the cellular blood components are returned to the patient together with a replacement fluid. By the extracorporeal removal of pathological substances and the replacement of deficient plasma components, it constitutes an important tool for the management of several disorders and it is a well-known and established treatment for numerous diseases. Additionally, overall available data confirm the safety and efficacy of TPE. Nevertheless, the quality of the evidence supporting the utility and efficacy of the procedure is diverse. This review attempts to compile the current indications of TPE in different disorders according to an extensive and updated literature review, with special focus on its present role and its validity in the twenty-first century medicine.

Prognostic significance of copy number alterations in adolescent and adult patients with precursor B acute lymphoblastic leukemia enrolled in PETHEMA protocols.

BACKGROUND: Some copy number alterations (CNAs) have independent prognostic significance for adults with acute lymphoblastic leukemia (ALL). METHODS: This study analyzed via multiplex ligation-dependent probe amplification the frequency and prognostic impact of CNAs of 12 genetic regions in 142 adolescents and adults with de novo precursor B-cell ALL. RESULTS: The cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) deletion (59 of 142 or 42%) was the most frequent CNA, and it was followed by Ikaros family zinc finger 1 (IKZF1) losses (49 of 142 or 35%). IKZF1 deletions were more prevalent in Philadelphia chromosome (Ph)-positive ALL and were associated with advanced age and high white blood cell (WBC) counts. The multivariate analysis showed that advanced age and early B-cell factor 1 (EBF1) deletions were associated with chemotherapy resistance in both the whole series (hazard ratios, 0.949 and 0.135, respectively) and the Ph-negative subgroup (hazard ratios, 0.946 and 0.118, respectively). High WBC counts and focal IKZF1 deletions correlated with disease recurrence (hazard ratios, 1.005 and 1.869, respectively), whereas advanced age and CDKN2A/B losses influenced overall survival in both the whole series (hazard ratios, 1.038 and 2.545, respectively) and the Ph-negative subgroup (hazard ratios, 1.044 and 2.105, respectively). CONCLUSIONS: Deletions of EBF1, IKZF1, and CDKN2A/B have an independent adverse prognosis for adolescents and adults with B-precursor ALL, and this suggests that these CNAs should be included in the initial risk assessment of ALL.

STAT3 mutations indicate the presence of subclinical T-cell clones in a subset of aplastic anemia and myelodysplastic syndrome patients.

Large granular lymphocyte leukemia (LGL) is often associated with immune cytopenias and can cooccur in the context of aplastic anemia (AA) and myelodysplastic syndromes (MDS). We took advantage of the recent description of signal transducer and activator of transcription 3 (STAT3) mutations in LGL clonal expansions to test, using sensitive methods, for the presence of these mutations in a large cohort of 367 MDS and 140 AA cases. STAT3 clones can be found not only in known LGL concomitant cases, but in a small proportion of unsuspected ones (7% AA and 2.5% MDS). In STAT3-mutated AA patients, an interesting trend toward better responses of immunosuppressive therapy and an association with the presence of human leukocyte antigen-DR15 were found. MDSs harboring a STAT3 mutant clone showed a lower degree of bone marrow cellularity and a higher frequency of developing chromosome 7 abnormalities. STAT3-mutant LGL clones may facilitate a persistently dysregulated autoimmune activation, responsible for the primary induction of bone marrow failure in a subset of AA and MDS patients.

STAT3 mutations unify the pathogenesis of chronic lymphoproliferative disorders of NK cells and T-cell large granular lymphocyte leukemia.

Chronic lymphoproliferative disorders of natural killer cells (CLPD-NKs) and T-cell large granular lymphocytic leukemias (T-LGLs) are clonal lymphoproliferations arising from either natural killer cells or cytotoxic T lymphocytes (CTLs). We have investigated for distribution and functional significance of mutations in 50 CLPD-NKs and 120 T-LGL patients by direct sequencing, allele-specific PCR, and microarray analysis. STAT3 gene mutations are present in both T and NK diseases: approximately one-third of patients with each type of disorder convey these mutations. Mutations were found in exons 21 and 20, encoding the Src homology 2 domain. Patients with mutations are characterized by symptomatic disease (75%), history of multiple treatments, and a specific pattern of STAT3 activation and gene deregulation, including increased expression of genes activated by STAT3. Many of these features are also found in patients with wild-type STAT3, indicating that other mechanisms of STAT3 activation can be operative in these chronic lymphoproliferative disorders. Treatment with STAT3 inhibitors, both in wild-type and mutant cases, resulted in accelerated apoptosis. STAT3 mutations are frequent in large granular lymphocytes suggesting a similar molecular dysregulation in malignant chronic expansions of NK and CTL origin. STAT3 mutations may distinguish truly malignant lymphoproliferations involving T and NK cells from reactive expansions.

Gastric Bleeding in Stem Cell Transplantation: A Focus on Gastric Vascular Ectasia Under Post-Transplant Cyclophosphamide, Sirolimus, and Mycophenolate Mofetil Prophylaxis.

BACKGROUND AND AIMS: Gastrointestinal bleeding (GIB) is a serious complication following allogeneic hematopoietic stem cell transplantation (HSCT), with limited data on its incidence and characteristics, particularly for upper gastrointestinal bleeding (UGIB) of gastric origin. We aimed to evaluate the incidence, clinical, endoscopic, and histopathologic features, and outcomes of UGIB, with a focus on gastric vascular ectasias (GVEs) in patients undergoing HSCT with graft-versus-host disease (GVHD) prophylaxis using post-transplant cyclophosphamide (PTCY), sirolimus or calcineurin inhibitors, and mycophenolate mofetil. METHODS: This retrospective, single-center study included all adult patients who underwent allogeneic HSCT at a single institution between January 2017 and December 2023. Data were collected on transplant procedures, complications, and GIB incidents, with UGIB cases undergoing endoscopic and histologic examination. RESULTS: Out of 559 patients, 38 (6.6%) experienced UGIB, with 27 cases (70%) attributed to GVE. GVE typically presented as melena or hematemesis at a median time of 68 days (range, 29-125) after transplant. Endoscopy revealed diffuse oozing from gastric antral mucosa without distinct lesions, while histology showed vascular congestion and mild foveolar hyperplasia. The 6-month cumulative incidence of GVE was 5.1%. Older age (≥60 years) and diagnosis of myelodysplastic/myeloproliferative neoplasm were significant risk factors. All cases resolved with no attributable mortality with supportive measures including transfusions, proton-pump inhibitors, and sirolimus withdrawal in some cases. CONCLUSIONS: GVE is a notable cause of UGIB in HSCT recipients on PTCY-based GVHD prophylaxis, presenting significant morbidity but favorable outcomes with appropriate management. The potential role of sirolimus and conditioning agents in GVE pathogenesis warrants further investigation.

New challenges of advanced therapies. / Nuevos retos de las terapias avanzadas.

The huge development that Advanced Therapy Medicinal Products (AMTPs) have experienced in recent years, both commercial and research, represent a challenge for Hospital Pharmacy at all levels. The aim of this article is to describe the implementation of an Advanced Therapies Unit (AUT) and the process of preparation of the AMTPs according to the "good manufacturing practices" (GMP), as well as the results obtained in a tertiary hospital, as an example of the challenges posed by MTA's academic production. The AUT meets the requirements established in the GMP by guaranteeing that the medicines produced therein are of the quality required for the use for which they are intended, and also provides support to various research groups involved in the development of AMTPs. The AUT is composed of a highly qualified multidisciplinary team, qualified and trained in GMP, and is authorized for the preparation of five types of AMTPs consisting of allogeneic virus-specific T cells (VST) with various viral specificities. A circuit has been established in collaboration between the UTA and the Pharmacy Service with the Hematology Service for the assessment of the clinical indication, the request and preparation of VST, which allows the treatment of patients receiving hematopoietic stem cell transplants who present viral reactivations resistant or refractory to standard treatment, or who cannot tolerate it due to toxicity. Preliminary results from these AMTPs suggest that VSTs are an effective and safe alternative. Academic AMTPs have special interest in orphan indications or in the absence of alternative treatments, and their production through the "hospital exemption" can favor early access in the initial phases of development and at a lower cost. It is essential to promote the training of hospital pharmacists in GMP and their participation in collaboration with other clinicians and researchers to develop AMTPs that meet all logistical and regulatory requirements.

[Translated article] New challenges in advanced therapies.

The huge development that advanced therapy medicinal products (AMTPs) have experienced in recent years, both commercial and research, represent a challenge for hospital pharmacy at all levels. The aim of this article is to describe the implementation of an advanced therapies unit (AUT) and the process of preparation of the AMTPs according to the "good manufacturing practices" (GMP), as well as the results obtained in a tertiary hospital, as an example of the challenges posed by MTA's academic production. The AUT meets the requirements established in the GMP by guaranteeing that the medicines produced therein are of the quality required for the use for which they are intended, and also provides support to various research groups involved in the development of AMTPs. The AUT is composed of a highly qualified multidisciplinary team, qualified and trained in GMP, and is authorized for the preparation of 5 types of AMTPs consisting of allogeneic virus-specific T cells (VST) with various viral specificities. A circuit has been established in collaboration between the UTA and the pharmacy service with the hematology service for the assessment of the clinical indication, the request, and preparation of VST, which allows the treatment of patients receiving hematopoietic stem cell transplants who present viral reactivations resistant or refractory to standard treatment, or who cannot tolerate it due to toxicity. Preliminary results from these AMTPs suggest that VSTs are an effective and safe alternative. Academic AMTPs have special interest in orphan indications or in the absence of alternative treatments, and their production through the "hospital exemption" can favor early access in the initial phases of development and at a lower cost. It is essential to promote the training of hospital pharmacists in GMP and their participation in collaboration with other clinicians and researchers to develop AMTPs that meet all logistical and regulatory requirements.

An update on the pathogenesis and diagnosis of thrombotic thrombocytopenic purpura.

INTRODUCTION: Severe ADAMTS13 deficiency defines thrombotic thrombocytopenic purpura (TTP). ADAMTS13 is responsible for VWF cleavage. In the absence of this enzyme, widespread thrombi formation occurs, causing microangiopathic anemia and thrombocytopenia and leading to ischemic organ injury. Understanding ADAMTS13 function is crucial to diagnose and manage TTP, both in the immune and hereditary forms. AREAS COVERED: The role of ADAMTS13 in coagulation homeostasis and the consequences of its deficiency are detailed. Other factors that modulate the consequences of ADAMTS13 deficiency are explained, such as complement system activation, genetic predisposition, or the presence of an inflammatory status. Clinical suspicion of TTP is crucial to start prompt treatment and avoid mortality and sequelae. Available techniques to diagnose this deficiency and detect autoantibodies or gene mutations are presented, as they have become faster and more available in recent years. EXPERT OPINION: A better knowledge of TTP pathophysiology is leading to an improvement in diagnosis and follow-up, as well as a customized treatment in patients with TTP. This scenario is necessary to define the role of new targeted therapies already available or coming soon and the need to better diagnose and monitor at the molecular level the evolution of the disease.

T Cell-Depleted Peripheral Blood versus Unmanipulated Bone Marrow in Matched Sibling Transplantation for Aplastic Anemia.

Bone marrow (BM) is the recommended stem cell source for hematopoietic stem cell transplantation (HSCT) from matched sibling donors (MSDs) in patients with severe aplastic anemia (SAA) for its superior survival and graft-versus-host disease (GVHD) outcomes compared to recipients of unmanipulated peripheral blood (PB) HSCT. Nevertheless, no studies comparing BM with ex vivo T cell-depleted (TCD) PB have been reported to date. The aim of the present study was to compare the transplantation outcomes of MSD HSCT recipients with SAA using PB (with partial ex vivo TCD targeted cell dose grafts) with those of MSD HSCT recipients with SAA using unmanipulated BM. We performed a matched-pair analysis of MSD-HSCT using TCD PB in a single institution with unmanipulated BM MSD-HSCT in the United States between 2013 and 2019 reported to the Center for International Blood and Marrow Transplant Research. We compared 23 recipients of TCD PB HSCT for SAA (cases) and 69 recipients of unmanipulated BM grafts (controls) matched for age, Karnofsky Performance Status, Hematopoietic Cell Transplantation-Specific Comorbidity Index, time from diagnosis to transplantation, and recipient cytomegalovirus serostatus. We found significantly faster neutrophil and platelet recovery in the TCD PB cohort (P < .001 and P = .03, respectively), as well as a lower incidence of grade II-IV acute GVHD (0% versus 17%; P = .05) and similar overall survival (96% versus 97% at 3 years; P = .8). Our study shows that TCD PB can be considered a safe source for MSD-HSCT in patients with SAA, with potential advantages in engraftment and GVHD that could challenge the standard with BM. These findings provide a basis for future research in a prospective controlled clinical trial.

Impact of Post-Transplantation Cyclophosphamide on Transfusion Requirements in HLA-Matched Sibling Peripheral Blood Stem Cell Transplantation.

Post-transplantation cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis is being increasingly used in allogeneic hematopoietic stem cell transplantation (allo-HSCT) from HLA-matched related donors (MRDs); however, information regarding the transfusion needs in this setting is lacking. This study compared RBC and platelet units transfused and time to transfusion independence according to the GVHD prophylaxis regimen in MRD HSCT. We performed a matched-pair analysis comparing the transfusion requirements and the clinical outcomes of patients who underwent MRD peripheral blood HSCT using PTCy between January 2017 and June 2021 (n = 100) with historical MRD HSCTs using standard cyclosporine A (CsA)-based prophylaxis (n = 100). Neutrophil engraftment was significantly delayed in the PTCy group compared with the CsA group (16 days versus 13 days; P = .003). PTCy was associated with increased RBC (median, 5 units versus 4 units; P = .04) and platelet (median, 6 units versus 3 units; P = .01) transfusion requirements during the first 30 days after transplantation. The proportion of patients requiring platelet transfusion during days 31 to 90 after transplantation was also higher in the PTCy group (55% versus 25%; P < .0001). In multivariate analysis, PTCy was associated with delayed RBC and platelet transfusion independence (hazard ratio, .61 [P = .007] and .51 [P < .0001], respectively). The cumulative incidence (CuI) of BK polyomavirus-associated hemorrhagic cystitis grade ≥2 at 100 days was higher in the PTCy group (34% versus 12%; P < .0001); however, the PTCy group had lower rates of grade II-IV acute GVHD (100-day CuI, 57% versus 23%; P < .0001) and moderate to severe chronic GVHD (1-year CuI, 49% versus 28%; P = .003), as well as better 2-year overall survival (74% versus 56%; P = .01). Our study shows that although PTCy increases the transfusion burden in MRD HSCT, it is associated with a low incidence of severe GVHD and with encouraging survival outcomes.

Transfusion Burden in Allogeneic Hematopoietic Stem Cell Transplantation over Time: Experience from a Single Institution.

INTRODUCTION: Transfusion plays a main role in supportive treatment for patients who receive an allogeneic hematopoietic stem cell transplantation (HSCT). In this study, we compare the transfusion requirements of patients undergoing different modalities of HSCT according to different time periods. The objective is to assess the evolution of HSCT transfusion requirements over time, from a single institution. METHODS: The clinical charts and transfusion records of patients who underwent HSCT of different modalities at La Fe University Hospital during a twelve-year period were reviewed (2009-2020). For analysis, we divided the overall time into three periods: 1 from 2009 to 2012, 2 from 2013 to 2016 and 3 from 2017 to 2020. The study included 855 consecutive adult HSCT: 358 HLA-matched related donors (MRD), 134 HLA-matched unrelated donors (MUD), 223 umbilical cord blood transplantation (UCBT) and 140 haploidentical transplants (Haplo-HSCT). RESULTS: There were no significant differences in RBC and PLT requirements or transfusion independence among the three time periods for MUD and Haplo-HSCT. However, the transfusion burden increased significantly for MRD HSCT during the 2017-2020 period. CONCLUSION: despite HSCT modalities having evolved and changed over time, overall transfusion requirements have not significantly decreased and continue to be a cornerstone of transplantation-supportive care.