Digital PCR Improves Sensitivity and Quantification in Monitoring CAR-T Cells in B Cell Lymphoma Patients.

Chimeric antigen receptor T cells (CAR-T) has emerged as a promising therapy, over 60% of patients fail to sustain a long-term response. The underlying factors that leads to the effectiveness of this therapy are not completely understood, CAR-T cell persistence and monitoring seems to be pivotal for ensuring a successful response. Various monitoring methods such as multiparametric flow cytometry (MFC) or quantitative PCR (qPCR) have been applied. Our objective is to develop digital PCR (dPCR) assays for detection and quantification of CAR-T cells, comparing them with MFC and qPCR. Samples taken at different follow-up times from 45 patients treated with CAR-T therapy were analyzed to assess the correlation between the different methodologies. dPCR presented a high correlation with MFC and qPCR (r = 0.97 and r = 0.87, respectively), while offering a higher sensitivity (0.01%) compared to MFC (0.1%) and qPCR (1%). dPCR emerged as an alternative and highly sensitivity method for monitoring CAR-T cell dynamics. This technique is well-suited for implementation in clinical practice as a complementary technique to MFC.

Advantages of high cell concentration prior to cryopreservation of initial leukapheresis in CAR-T cell therapy.

BACKGROUND: Chimeric antigen receptor (CAR) T-cell therapy is increasingly used in patients affected by B-cell lymphoma and acute lymphoblastic leukemia. For logistical reasons, initial apheresis products may be cryopreserved for shipment to manufacturing centers. Due to the characteristics of these patients, cells are often collected in large volumes, meaning more bags must be cryopreserved. This requires increased storage, time and monetary costs. In this context, we aimed to evaluate a high cell concentration cryopreservation protocol by centrifugation to standardize the initial CAR-T manufacturing procedure. MATERIALS AND METHODS: Sixty-eight processes of leukapheresis of 57 patients affected by refractory/relapsed B cell lymphoma and 9 patients affected by acute lymphoblastic leukemia who were eligible for anti-CD19 CAR-T cell treatment performed between June 2019 and October 2022 were analyzed. Whole blood count, percentage and number of T cells were assessed on the apheresis final product. The apheresis product, which was alternatively stored overnight at 4°C, was centrifuged, adjusting the volume to approximately 40 mL. The product was immediately cryopreserved to achieve a final cell concentration of 50-200×106 cells/ml for cryopreservation. RESULTS: Leukapheresis volume was reduced by almost fivefold (median: 185 to 40 mL), resulting in a higher product concentration in one bag. In addition, the number of non-target cells (monocytes, platelets and erythrocytes) was also reduced during the development of CAR T cell therapy, thereby maintaining T lymphocyte levels and providing a purer starting material. DISCUSSION: The advantages of the protocol include reducing economic costs, saving storage space, simplifying the manufacturing process, and facilitating shipping logistics. In conclusion, we present a validated, simple, and cost-effective cell enrichment processing protocol that provides high-quality cryopreserved products as starting material for the CAR-T cell manufacturing process.

Red Blood Cell Transfusion after Postpartum Hemorrhage: Clinical Variables Associated with Lack of Postpartum Hemorrhage Etiology Identification.

Postpartum hemorrhage (PPH) remains a significant obstetric emergency worldwide and a leading cause of maternal death. However, it is commonly underreported, which can represent a major concern for maternal morbidity and mortality. This retrospective case series study analyzed patients with red blood cell transfusion (RBCt) in the postpartum period over a four-year interval at a specific center. A total of 18,674 patients delivered between January 2018 and December 2021. Patients with postpartum RBCt were classified into two groups: those with identified PPH (i-PPH) and those without (non-i-PPH). Clinical variables, delivery details, blood loss data, and treatment information were collected. Statistical analysis involved a comparison of variables between the i-PPH and non-i-PPH groups. Univariate and multivariate analyses were performed, aiming to identify significant associations between the clinical variables and a lack of PPH identification. The incidence of RBCt was 1.26% (236 cases). Patients receiving RBCt had higher rates of cesarean delivery, twin pregnancy, labor induction, and previous cesarean section. Among patients with postpartum RBCt, 34.3% lacked an identified PPH. The rarity of postpartum RBCt contrasts with the increasing rates of PPH, highlighting the importance of diagnosing PPH and postpartum anemia. A strategy of systematic quantification of blood loss during delivery could help detect PPH and anemia before adverse consequences occur.

Allogeneic CD34-selected stem cell boost as salvage treatment of life-threatening infection and severe cytopenias after CAR-T cell therapy.

BACKGROUND: A variable incidence of profound cytopenia has been described in patients receiving chimeric antigen receptor T-cell (CAR-T) therapy for relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (ALL). This complication leads to severe infection in some cases, especially those who present additional risk factors including prior hematopoietic stem cell transplantation (HSCT). STUDY DESIGN AND METHODS: We report a case of breakthrough invasive fungal infection in a patient with prolonged neutropenia after CAR-T cell therapy administered for relapsed B-cell ALL after allogeneic haploidentical HSCT. RESULTS: After disease progression was discarded, therapy with antifungal agents, G-CSF and thrombopoietin analogue was started. However, no sign of haematological recovery or infection improvement was observed. A fresh mobilized selected CD34-stem cell boost from her haploidentical transplant donor was infused without further conditioning. Within 15 days of mobilized CD34-boost administration the patient showed complete resolution of both the aplasia and fungal infection. DISCUSSION: This case illustrates as proof-of-concept the efficacy and safety of selected CD34-stem cell boost from prior donor as salvage treatment of prolonged cytopenias after CAR-T cell therapy.

Maternal mirror syndrome with foetal hydrops due to isoimunization by anti-KPa antibodies: A case report and narrative literature review.

We present a rare case of mirror syndrome due to anti-Kpa antibodies, which can be difficult to identify with routine screening tests.

Hemophagocytic lymphohistiocytosis/macrophage activation syndrome (HLH/MAS) following treatment with tisagenlecleucel.

Chimeric antigen receptor (CAR) T cell-related HLH/MAS is an unusual manifestation of severe cytokine release syndrome (CRS) with poor prognosis and a challenging diagnosis. The establishment of specific diagnosis criteria is essential, and the combination of several techniques for CAR T-cell follow-up, allows a more precise management of this complication.

Clinical grade production of IL-15 stimulated NK cells for early infusion in adult AML patients undergoing haploidentical stem cell transplantation with post-transplant cyclophosphamide.

BACKGROUND: Allogeneic stem cell transplantation is the treatment of choice for acute myeloid leukemia (AML) patients. Unmanipulated haploidentical transplantation (Haplo-HSCT) is commonly used for those AML patients who need a timely transplant and do not have a suitable matched donor, but relapse rates are still high, and improvements are needed. Adoptive immunotherapy using natural killer cells (NK cells) could be a promising tool to improved Haplo-HSCT but, to date, no optimal infusion and manufacturing protocols have been developed. STUDY DESIGN AND METHODS: In this study, we describe a quick and reproducible protocol for clinical-grade production of haploidentical donor NK cells using double immunomagnetic depletion and enrichment protocol and overnight IL-15 stimulation. RESULTS: Thus, we have obtained 8 viable and functional NK cell products that have been safely infused to five AML patients undergoing unmanipulated Haplo-HSCT. DISCUSSION: Our results demonstrate the safety and feasibility of manufactured NK IL15 cells obtained from an adult allogeneic donor in the setting of haploidentical transplantation for AML patients.

Application of the French TMA Reference Center Score and the mortality in TTP Score in de novo and relapsed episodes of acquired thrombotic thrombocytopenic purpura at a tertiary care facility in Spain.

Acquired thrombotic thrombocytopenic purpura (aTTP) is still associated with a 10% to 20% death rate and its clinical course is characterized by recurrent episodes in up to 50% of cases. Over the last decade, mortality predicting models like the French TMA Reference Center Score and the Mortality In TTP Score (MITS) have been developed in an attempt to personalize treatment. The objective of the present study was to compare the results in both scores of de novo and relapsed aTTP episodes. For such purpose, a total of 29 episodes of aTTP (16 de novo and 13 relapses) were analyzed. All patients were homogeneously diagnosed and treated. First episodes had a higher score in both models in comparison with relapsed aTTP, (MITS median, 1 r: 1-4 vs 0 r: 1-2, P = .038 and French TMA Reference Center Score median, 2 r: 1-3 vs 1 r: 0-1, P = .006). The prevalence of neurological symptoms was significantly higher in the first episodes (P = .001) and patients >60 years old were more common in this group (P = .013), which may have been related to the results. Platelet count at presentation was higher in recurrences than in the first disease episode (P = .016) and ADAMTS13 activity <5% was more frequent in the last group (P = .016). There was no significant difference in the rate of refractoriness or exacerbations. In conclusion, first aTTP episodes had a higher probability of short-term mortality compared to relapsed aTTP episodes according to the MITS and French TMA Reference Center Score.

Complete RH and Kell matching related to low alloimmunisation risk in sickle cell disease: prevalence and risk factors of alloimmunisation in a Spanish Tertiary Care National Reference Centre.

BACKGROUND: Red blood cell (RBC) transfusion remains an essential part of sickle cell disease (SCD) management but it can lead to alloimmunisation, with an increased incidence in this population. Prevention is based on RBC antigen phenotype matching, with complete RH and Kell matching being a standard of care. MATERIALS AND METHODS: We performed a retrospective, single-centre study analysing alloimmunisation prevalence and risk factors in a cohort of transfused SCD patients. RESULTS: Eighty-seven patients (96.5% of paediatric age) received 1,781 RBC units (RBCu). Complete RH and Kell matched RBCu represented a median of 100% among total transfusions per patient. Of the 87 patients, 52 (59.8%) underwent chronic transfusion therapy, whereas 35 (40.2%) were only episodically transfused. Seven patients were alloimmunised (8.4%) and eleven antibodies were detected (alloimmunisation rate: 0.62/100 units transfused). 54.6% of these antibodies corresponded to RH-Kell despite the high accomplishment of the RH-Kell matching transfusion protocol. Alloimmunised patients had a median of 90.9% RH-Kell matched transfusions vs 100% in non-alloimmunised patients, but no statistical differences were observed (p=0.127). Number of transfused RBCu (19 vs 7; p=0.023), number of episodic RBCu (8 vs 2; p=0.006), episodic to chronic RBCu ratio (0.57 vs 0.09; p=0.045), number of vaso-occlusive crises (VOC) (4 vs 2; p=0.011), and autoantibody presence (57.1 vs 0%; p<0.001) were all statistically related to alloimmunisation. DISCUSSION: We report a low alloimmunisation prevalence (8.4%) related to a high grade of RH-Kell matching. However, deviation from 100% translates into alloimmunisation, with >50% of alloantibodies corresponding to RH-Kell. Alloimmunisation risk increases with transfusion burden, particularly during acute complications, and in patients with a higher number of VOC, probably reflecting underlying inflammation and disease severity. Further studies will be needed to elucidate additional risk factors and help prevent alloimmunisation in these patients.

Factors predicting peripheral blood progenitor cell mobilization in healthy donors in the era of related alternative donors: Experience from a single center.

BACKGROUND: Poor mobilization results are unexpected after G-CSF-induced peripheral blood stem cell collection in healthy donors. However, 2%-5% of the donors are poor mobilizers. Factors predicting CD34+-cell yield after mobilization in related alternative donors are still poorly known. PATIENTS AND METHODS: Baseline characteristics and efficacy results of G-CSF induced mobilization of 159 adult healthy donors in our institution from 2008 to 2016 were retrospectively analyzed. All donors received 10 µg/kg of G-CSF once a day subcutaneously for 4 days. Leukapheresis started on the 5th day of G-CSF treatment. Donors were classified as poor mobilizers if they had less than 20 000 CD34 + cell/mL peripheral blood count in the 5th day of G-CSF treatment or if they needed three or more leukapheresis for graft collection. RESULTS: Age, weight, and platelet count before and after mobilization were significantly different between poor and good mobilizers. Poor mobilizers (n = 16) were older (50.6 vs 41.7 years, P = 0.002), weight lower (64 vs 75 kg, P = 0.00) and showed a lower platelet count before (199.5 vs 219.0 × 109 /L, P = 0.03) and after (192.5 vs 206 × 109 /L, P = 0.019) mobilization. In the multivariate analysis only the 30% of the variability of mobilization was explained by the model (sensitivity 80%, specificity 70%). CONCLUSION: In this cohort of healthy donors in a single institution, older age, less weight, and lower platelet count was associated with poorer mobilization. With clinical and analytic factors it is not possible to predict more than 30% of the variability. Further studies are needed to investigate new variables.

Mononuclear cell collection for extracorporeal photopheresis by using the "off-line" system: A comparative study between COBE Spectra and Spectra Optia devices.

BACKGROUND: Extracorporeal photopheresis (ECP) is an efficient and established therapy to treat acute and chronic graft vs host disease (GVHD). Using an "off-line" method, the first step (mononuclear cell [MNC] collection) is decisive, as long as a high MNC yield and purity in the collected product is desirable. Two "off-line" devices were compared: the COBE Spectra and the Spectra Optia (Terumo BCT), using both continuous and intermittent protocols. PATIENTS AND METHODS: Twelve patients with GvHD (7 acute/5 chronic) were enrolled between June 2014 and May 2015 and were alternatively assigned for each procedure to either the COBE Spectra or the Spectra Optia cell separator. Patients characteristics and procedure/product parameters were analyzed. RESULTS: Two hundred procedures (100 per device) were included. The Spectra Optia system showed higher total nucleated cells and MNC collection efficiencies (18.6(10.2-29.7) vs 7.9(4.1-14.8)% and 43.6(20.3-59.5) vs 23.3(11.4-37.1)%, P < .001) and monocyte and lymphocyte collection efficiencies (55.2(17.7-83.2) vs 22.8(9-38.9)% and 38.3(26.7-53.4) vs 22.2(9-38.9)%, respectively, P < .001). Absolute platelet loss (PL) and PL per liter of blood processed were significantly lower in the Spectra Optia group (22.9(18.3-28.1) vs 33.6(26.5-41.1)%, P < .001 and 3.7(3.1-4.5) vs 4.3(3.5-4.2)%, P = .01, respectively). However, granulocyte contamination was higher (4.5(1.3-36) vs 1.2(0.4-5.7)%, P < .001) and a higher product haematocrit was obtained with the Spectra Optia (1(0.5-1.6) vs 0.3(0.2-0.5)%, P < .001), without an impact on irradiation time. CONCLUSIONS: In our study, Spectra Optia proved to be safe and effective in collecting MNC with high yield and purity for ECP in GvHD.

Busulfan-based myeloablative conditioning regimens for haploidentical transplantation in high-risk acute leukemias and myelodysplastic syndromes.

BACKGROUND: High-risk acute leukemia (AL) and myelodysplastic syndrome (MDS) remain a therapeutic challenge. Unmanipulated haploidentical-related donor transplantation based on a myeloablative conditioning regimen (HAPLO-MAC) and post-transplant cyclophosphamide (PT-Cy) as prophylaxis against graft vs host disease (GvHD) is now a promising rescue strategy that could become universally available. OBJECTIVE: To evaluate the results of HAPLO-MAC with PT-Cy in patients with AL and MDS reported to the Haploidentical Transplantation Subcommittee of the Spanish Group for Hematopoietic Transplantation (GETH). PATIENTS AND METHODS: We report our multicenter experience using an IV busulfan-based HAPLO-MAC regimen and PT-Cy for treatment of 65 adults with high-risk AL and MDS. RESULTS: Engraftment was recorded in 64 patients (98.5%), with a median time to neutrophil and platelet recovery of 16 and 27 days, respectively. The cumulative incidence of grade II-IV acute GvHD and chronic GvHD was 28.6% and 27.5%, respectively. After a median follow-up of 31 months for survivors, the cumulative incidence of non-relapse mortality and relapse at 2 years was 18.8% and 25%, respectively. Estimated 30-month event-free survival and overall survival were 56% and 54.5%, respectively. CONCLUSION: HAPLO-MAC comprising an IV busulfan-based conditioning regimen enabled long-term disease control with acceptable toxicity in high-risk AL and MDS.

Multicenter comparison of CD34+ myeloid cell count by flow cytometry in low-risk myelodysplastic syndrome. Is it feasible?

BACKGROUND: Accuracy of bone marrow (BM) blast count in low-risk myelodysplastic syndromes (MDS) still remains a challenge though it is essential for prognosis. We investigated whether the enumeration of CD34+ myeloid cells by flow cytometry immunophenotyping (FCI) could be used as a consistent parameter for clinical MDS studies. METHODS: Six clinical centers entered the study and information on their FCI protocols was recorded. Sixty-seven flow cytometry listmodes from BM samples of patients with low-risk MDS with <5% BM blasts were exchanged among participants in two different rounds. Interlaboratory variations on the quantification of CD34+ myeloid cells were calculated and strategies to solve differences were evaluated. RESULTS: An overall "very good" agreement on CD34+ cell count among participants (intraclass correlation coefficient = 0.720) was observed, but agreement was "low" in 22 files. No single parameter could fully explain all discrepancies, but 3 technical issues were identified as relevant: the use of the CD34/CD45/CD117/HLA-DR mAb combination, acquisition of ≥50,000 events and a low percentage of debris/aggregates. The frequency of discordant results increased with the accumulation of pitfalls (none, 16%; 1 pitfall, 40%; 2 pitfalls, 83%; P = 0.006). Finally, the use of a common gating strategy for analysis increased the percentage of files with "very good" agreement to 100%. CONCLUSIONS: Prevention of specific technical pitfalls is mandatory to reach a good reproducibility of CD34+ cell count among centers. These recommendations set the basis for laboratory standardization and enable the use of CD34+ cell enumeration as additional information in low-risk MDS patients. © 2017 International Clinical Cytometry Society.

Transient hemolysis due to anti-D and anti-A1 produced by engrafted donor's lymphocytes after allogeneic unmanipulated haploidentical hematopoietic stem cell transplantation.

BACKGROUND: Development of de novo alloantibodies against recipient's red blood cell (RBC) antigens by engrafted donor's lymphocytes is a known phenomenon in the setting of allogeneic hematopoietic stem cell transplantation (HSCT). This situation is usually clinically insignificant. We report a case of early clinically relevant hemolytic anemia in a blood group A1 D+ patient, due to a limited production of anti-D and anti-A1 produced by nonpreviously sensitized newly engrafted donor's immune system. CASE REPORT: A 31-year-old Caucasian woman, blood group A1 , D+, with Hodgkin's lymphoma, received an unmanipulated haploidentical allogeneic peripheral blood HSCT after a nonmyeloablative conditioning regimen. Donor blood group was A2 B, D-. The patient had an uneventful course until Day +34, when she developed clinically significant hemolytic anemia with a positive direct antiglobulin test. Anti-D and anti-A1 produced by the donor-engrafted lymphocytes were detected both in serum and in eluate. The hemolysis produced an accelerated group change, turning the patient's ABO group into A2 B 2 weeks after the detection of the alloantibodies. As the residual patient's RBCs progressively disappeared, anti-D and anti-A1 production decreased and were not detected in serum by Day +41. CONCLUSION: This case illustrates that de novo alloantibody production against ABO and D antigens by the newly engrafted donor's lymphocytes can occasionally cause clinically significant anemia. To our knowledge, this is the first case reported of clinically significant hemolytic anemia due to a transient anti-D anti-A1 alloimmunization after T-cell-repleted haploidentical HSCT.

Trasplante de médula ósea en pacientes con anemia falciforme. Experiencia en un centro / Bone marrow transplant in patients with sickle cell anaemia. Experience in one centre

INTRODUCCIÓN: La enfermedad de células falciformes (ECF), pese a la mejora en el manejo médico, persiste asociada a morbilidad y a menor supervivencia. El alotrasplante de progenitores hematopoyéticos (alo-TPH) es actualmente la única opción curativa. Describir la evolución clínico-analítica de los pacientes trasplantados en nuestro centro. MATERIAL Y MÉTODO: Estudio unicéntrico descriptivo, incluye a pacientes con ECF en los que se realiza alo-TPH de médula ósea de hermano HLA-idéntico desde enero del 2010 hasta diciembre del 2014. Se recogen datos epidemiológicos, clínicos y analíticos con tiempo de seguimiento hasta diciembre del 2015. Los datos se presentan como frecuencias, porcentajes y medianas (rango). RESULTADOS: Se recluta a 11 pacientes (8 varones), mediana de edad: 7 años (2-13), todos ellos con comorbilidad previa al TPH. Se consigue injerto estable en 10/11 pacientes, quimerismo completo en 9/11 y quimerismo mixto estable tras un año del TPH en 1/11. Un paciente presenta fallo secundario de injerto con reaparición de clínica el día +180. Complicaciones post-TPH: complicaciones neurológicas 4/11 pacientes (hemorragia subaracnoidea, crisis), HTA 7/11, fallo renal agudo 3/11, reactivación CMV 9/11, EICHa cutáneo 6/11, uno de ellos desarrolla EICH intestinal grado IV causando su fallecimiento (día +51). Ningún paciente desarrolla EICH crónico. Supervivencia global y libre de eventos a los 3,1 años de seguimiento: 90,9 y 81,9%, respectivamente. CONCLUSIONES: El alo-TPH, única opción curativa, no está exento de morbimortalidad, encontramos un riesgo de muerte similar a otras series (1/11), siendo su primera causa el EICH agudo. Otros problemas son fallo de injerto (1/11) y complicaciones neurológicas (4/11), aunque las secuelas permanentes son leves

INTRODUCTION: Sickle cell disease (SCD), despite the improvement in the medical management, is still associated with severe morbidity and decreased survival. Allogenic hematopoietic stem cell transplantation (Allo-HSCT) currently provides the only curative therapy. A report is presented on our experience in children with SCD, who underwent Allo-HSCT in a single centre. Material and method. A single centre descriptive study was conducted on patients with SCD who underwent a bone marrow transplant from an HLA-identical sibling donor between January 2010 and December 2014. Epidemiological, clinical and analytical parameters were collected with a follow-up to December 2015. Data are presented as frequencies, percentages, and medians (range). RESULTS: Allo-HCST was performed in 11 patients (8 males) with a median age of 7 years (2-13), all of them with comorbidity prior to the HCST. A stable graft was achieved in 10 out of 11 patients, 9 of them with complete donor chimerism, and one patient with stable mixed chimerism after 1 year of allo-HSCT. One patient has secondary graft failure with re-appearance of symptoms associated with SCD on day 180. Complications of Allo-HSCT are: arterial hypertension 7/11, acute renal failure 3/11, CMV reactivation 9/11, neurological complications 4/11 (subarachnoid haemorrhage, seizure), and acute graft versus host disease (aGVHD) of the skin 6/11, one of whom developed grade IV intestinal aGVHD, causing his death (day 51). None of the patients developed chronic GVHD. The overall survival and event-free survival was 90.9% and 81.9%, respectively, with a median follow-up of 3.1 (1-5.7) years. CONCLUSIONS: Allo-HSCT, the only curative therapy, remains associated with morbidity. There was a transplant related mortality in our study, consistent with multicentre studies (1/11), and with aGVHD being the main cause. Other problems still include graft failure (1/11), and neurological complications (4/11), although the permanent sequelae are mild

[Bone marrow transplant in patients with sickle cell anaemia. Experience in one centre]. / Trasplante de médula ósea en pacientes con anemia falciforme. Experiencia en un centro.

INTRODUCTION: Sickle cell disease (SCD), despite the improvement in the medical management, is still associated with severe morbidity and decreased survival. Allogenic hematopoietic stem cell transplantation (Allo-HSCT) currently provides the only curative therapy. A report is presented on our experience in children with SCD, who underwent Allo-HSCT in a single centre. MATERIAL AND METHOD: A single centre descriptive study was conducted on patients with SCD who underwent a bone marrow transplant from an HLA-identical sibling donor between January 2010 and December 2014. Epidemiological, clinical and analytical parameters were collected with a follow-up to December 2015. Data are presented as frequencies, percentages, and medians (range). RESULTS: Allo-HCST was performed in 11 patients (8 males) with a median age of 7 years (2-13), all of them with comorbidity prior to the HCST. A stable graft was achieved in 10 out of 11 patients, 9 of them with complete donor chimerism, and one patient with stable mixed chimerism after 1 year of allo-HSCT. One patient has secondary graft failure with re-appearance of symptoms associated with SCD on day 180. Complications of Allo-HSCT are: arterial hypertension 7/11, acute renal failure 3/11, CMV reactivation 9/11, neurological complications 4/11 (subarachnoid haemorrhage, seizure), and acute graft versus host disease (aGVHD) of the skin 6/11, one of whom developed grade iv intestinal aGVHD, causing his death (day 51). None of the patients developed chronic GVHD. The overall survival and event-free survival was 90.9% and 81.9%, respectively, with a median follow-up of 3.1 (1-5.7) years. CONCLUSIONS: Allo-HSCT, the only curative therapy, remains associated with morbidity. There was a transplant related mortality in our study, consistent with multicentre studies (1/11), and with aGVHD being the main cause. Other problems still include graft failure (1/11), and neurological complications (4/11), although the permanent sequelae are mild.

Diagnostic screening of paroxysmal nocturnal hemoglobinuria: Prospective multicentric evaluation of the current medical indications.

BACKGROUND: Although consensus guidelines have been proposed in 2010 for the diagnostic screening of paroxysmal nocturnal hemoglobinuria (PNH) by flow cytometry (FCM), so far no study has investigated the efficiency of such medical indications in multicentric vs. reference laboratory settings. METHODS: Here we evaluate the efficiency of consensus medical indications for PNH testing in 3,938 peripheral blood samples submitted to FCM testing in 24 laboratories in Spain and one reference center in Brazil. RESULTS: Overall, diagnostic screening based on consensus medical indications was highly efficient (14% of PNH+ samples) both in the multicenter setting in Spain (10%) and the reference laboratory in Brazil (16%). The highest frequency of PNH+ cases was observed among patients screened because of bone marrow (BM) failure syndrome (33%), particularly among those with aplastic anemia (AA; 45%) and to a less extent also a myelodysplastic syndrome (MDS; 10%). Among the other individuals studied, the most efficient medical indications for PNH screening included: hemolytic anemia (19%), hemoglobinuria (48%) and unexplained cytopenias (9%). In contrast, only a minor fraction of the patients who had been submitted for PNH testing because of unexplained thrombosis in the absence of cytopenia, were positive (0.4%). CONCLUSIONS: In summary, our results demonstrate that the current medical indications for PNH screening by FCM are highly efficient, although improved screening algorithms are needed for patients presenting with thrombosis and normal blood cell counts. © 2016 International Clinical Cytometry Society.

Inhibitory killer cell immunoglobulin-like receptor (iKIR) mismatches improve survival after T-cell-repleted haploidentical transplantation.

Alloreactivity triggered by interaction between killer cell immunoglobulin-like receptors (KIRs) and natural killer (NK) cells plays a role in the graft-versus-tumor effect after hematopoietic stem cell transplantation (SCT). Our aim in this study was to evaluate this role in the setting of T-cell-repleted haploidentical SCT with postinfusion high-dose cyclophosphamide (PT-Cy). We included 33 patients. Among patient-donor pairs with at least 1 inhibitory KIR (iKIR) gene mismatch, event-free survival (EFS) and cumulative incidence of relapse 1 year after transplant were significantly better (85% vs. 37% [P = 0.008] and 18% vs. 46% [P = 0.041], respectively). A subanalysis in 12 patients with Hodgkin's lymphoma (HL) showed an improvement in EFS 1 year after transplant in those patients with KIR ligand mismatch (100% vs. 25%, P = 0.012), although overall survival (OS) was not affected (85% vs. 80%, P = 0.2). Eight of 12 patient-donors pairs presented iKIR mismatches. Of note, this outcome was better in the small subgroup, both for EFS (100% vs. 25%, P = 0.012) and for OS (100% vs. 37%, P = 0.004). Our data suggest that in the setting of T-cell-repleted haploidentical SCT with PT-Cy, iKIR mismatch is associated with improved survival, with particularly good results for both iKIR and KIR ligand mismatches in patients with HL.