Next Generation Flow for highly sensitive and standardized detection of minimal residual disease in multiple myeloma.

Flow cytometry has become a highly valuable method to monitor minimal residual disease (MRD) and evaluate the depth of complete response (CR) in bone marrow (BM) of multiple myeloma (MM) after therapy. However, current flow-MRD has lower sensitivity than molecular methods and lacks standardization. Here we report on a novel next generation flow (NGF) approach for highly sensitive and standardized MRD detection in MM. An optimized 2-tube 8-color antibody panel was constructed in five cycles of design-evaluation-redesign. In addition, a bulk-lysis procedure was established for acquisition of ⩾107 cells/sample, and novel software tools were constructed for automatic plasma cell gating. Multicenter evaluation of 110 follow-up BM from MM patients in very good partial response (VGPR) or CR showed a higher sensitivity for NGF-MRD vs conventional 8-color flow-MRD -MRD-positive rate of 47 vs 34% (P=0.003)-. Thus, 25% of patients classified as MRD-negative by conventional 8-color flow were MRD-positive by NGF, translating into a significantly longer progression-free survival for MRD-negative vs MRD-positive CR patients by NGF (75% progression-free survival not reached vs 7 months; P=0.02). This study establishes EuroFlow-based NGF as a highly sensitive, fully standardized approach for MRD detection in MM which overcomes the major limitations of conventional flow-MRD methods and is ready for implementation in routine diagnostics.

Results of allogeneic stem cell transplantation in the Spanish MDS registry: prognostic factors for low risk patients.

Although new agents have been approved for the treatment of MDS, the only curative approach is allogeneic hematopoietic stem cell transplantation (HSCT) and thus, in particular circumstances this procedure has been proposed as a treatment option for low risk patients. We have retrospectively analyzed the results of HSCT in 291 patients from the Spanish MDS registry with special attention to low risk MDS (LR-MDS) in order to define the variables that could impact their clinical evolution after transplantation. At 2 years OS was 51% and EFS was 50% (95% CI 0.7-4.5 years for OS and 95% CI 0.1-3.9 years for EFS). Among 43 LR-MDS, transplant-related mortality was 28%. At 3 years, OS was 67% (95% CI 264.7-8927.2 days for OS) and EFS was 64% (95% CI 0-9697.2 days for EFS). In the multivariate analysis only cytogenetics retained statistical significant effect on both OS (p=.047) and EFS (p=.046). Conditioning regimen could improve outcome among this subset of patients (OS 86% and RFS 100% for patients receiving RIC regimen). The present study confirms that specific disease characteristic as well as transplant characteristics have a significant impact on transplant outcome. Regarding low risk patients a non-myeloablative conditioning would be preferable especially in cases without high-risk cytogenetics.

Risk factors for thrombotic microangiopathy in allogeneic hematopoietic stem cell recipients receiving GVHD prophylaxis with tacrolimus plus MTX or sirolimus.

Transplantation-associated thrombotic microangiopathy (TA-TMA) is a feared complication of allogeneic hematopoietic SCT (HSCT) owing to its high mortality rate. The use of calcineurin inhibitors or sirolimus (SIR) for GVHD prophylaxis has been suggested as a potential risk factor. However, the impact of tacrolimus (TAC) and SIR combinations on the increased risk of TA-TMA is currently not well defined. We retrospectively analyzed the incidence of TA-TMA in 102 allogeneic HSCT recipients who consecutively received TAC plus SIR (TAC/SIR) (n=68) or plus MTX (TAC/MTX)±ATG (n=34) for GVHD prophylaxis. No significant differences were observed in the incidence of TA-TMA between patients receiving TAC/SIR vs TAC/MTX±ATG (7.4% vs 8.8%, P=0.8). Only grade III-IV acute GVHD, previous HSCT and serum levels of TAC >25 ng/mL were associated with a greater risk of TA-TMA. Patients developing TA-TMA have significantly poorer survival (P<0.001); however, TA-TMA ceased to be an independent prognostic factor when it was included in a multivariate model. In conclusion, the combination of TAC/SIR does not appear to pose a higher risk of TA-TMA. By contrast, we identified three different risk groups for developing TA-TMA.

Effects of MSC coadministration and route of delivery on cord blood hematopoietic stem cell engraftment.

Hematopoietic stem cell transplantation (HSCT) using umbilical cord blood (UCB) progenitors is increasingly being used. One of the problems that may arise after UCB transplantation is an impaired engraftment. Either intrabone (IB) injection of hematopoietic progenitors or mesenchymal stem cell (MSC) coadministration has been proposed among the strategies to improve engraftment. In the current study, we have assessed the effects of both approaches. Thus, NOD/SCID recipients were transplanted with human UCB CD34+ cells administered either intravenously (IV) or IB, receiving or not bone marrow (BM)-derived MSCs also IV or IB (in the right femur). Human HSC engraftment was measured 3 and 6 weeks after transplantation. Injected MSCs were tracked weekly by bioluminescence. Also, lodgment within the BM niche was assessed at the latter time point by immuno-fluorescence. Our study shows regarding HSC engraftment that the number of BM human CD45+ cells detected 3 weeks after transplantation was significantly higher in mice cotransplanted with human MSCs. Moreover, these mice had a higher myeloid (CD13+) engraftment and a faster B-cell (CD19+) chimerism. At the late time point evaluated (6 weeks), human engraftment was higher in the group in which both strategies were employed (IB injection of HSC and MSC coadministration). When assessing human MSC administration route, we were able to track MSCs only in the injected femurs, whereas they lost their signal in the contralateral bones. These human MSCs were mainly located around blood vessels in the subendosteal region. In summary, our study shows that MSC coadministration can enhance HSC engraftment in our xenogenic transplantation model, as well as IB administration of the CD34+ cells does. The combination of both strategies seems to be synergistic. Interestingly, MSCs were detected only where they were IB injected contributing to the vascular niche.

Optimisation of mesenchymal stromal cells karyotyping analysis: implications for clinical use.

PURPOSE: The aim of this study was to optimise the yield of metaphases in mesenchymal stromal cells (MSC) in vitro cultures and to study the karyotype of MSC expanded in good manufacturing practice (GMP) conditions for clinical use. BACKGROUND: MSC are being increasingly used in clinical trials for a number of diseases. Biosafety demonstration in all cases is mandatory. Unfortunately, current standard karyotyping methods fail to obtain enough number of evaluable metaphases. METHODS AND MATERIALS: In the present work, to optimise the yield of metaphases in MSC expanded in vitro, we have tested several conditions by modifying colcemid concentration (we have tested 0.01, 0.05 and 0.1 µg mL(-1) ) and exposure time (during 5, 15 and 24 h). We further applied these optimised conditions to 61 MSC expansions in GMP conditions for clinical use. RESULTS: Our results show that the highest number of metaphases was obtained when MSC were incubated with 0.05 µg mL(-1) of colcemid overnight (15 h), compared to the remaining experimental conditions. In most cases (59/61 cases) enough number of metaphases was obtained. And what is more relevant, only in one case a karyotypic abnormality was found (trisomy of chromosome 10), and cells were subsequently discarded for clinical use. CONCLUSION: We describe here an optimal method to obtain enough number of metaphases for karyotype analysis of in vitro expanded MSCs, what is essential for their clinical use in cell therapy programmes.

Mesenchymal stem cells from multiple myeloma patients display distinct genomic profile as compared with those from normal donors.

It is an open question whether in multiple myeloma (MM) bone marrow stromal cells contain genomic alterations, which may contribute to the pathogenesis of the disease. We conducted an array-based comparative genomic hybridization (array-CGH) analysis to compare the extent of unbalanced genomic alterations in mesenchymal stem cells from 21 myeloma patients (MM-MSCs) and 12 normal donors (ND-MSCs) after in vitro culture expansion. Whereas ND-MSCs were devoid of genomic imbalances, several non-recurrent chromosomal gains and losses (>1 Mb size) were detected in MM-MSCs. Using real-time reverse transcription PCR, we found correlative deregulated expression for five genes encoded in regions for which genomic imbalances were detected using array-CGH. In addition, only MM-MSCs showed a specific pattern of 'hot-spot' regions with discrete (<1 Mb) genomic alterations, some of which were confirmed using fluorescence in situ hybridization (FISH). Within MM-MSC samples, unsupervised cluster analysis did not correlate with particular clinicobiological features of MM patients. We also explored whether cytogenetic abnormalities present in myelomatous plasma cells (PCs) were shared by matching MSCs from the same patients using FISH. All MM-MSCs were cytogenetically normal for the tested genomic alterations. Therefore we cannot support a common progenitor for myeloma PCs and MSCs.

Both expanded and uncultured mesenchymal stem cells from MDS patients are genomically abnormal, showing a specific genetic profile for the 5q- syndrome.

The presence of cytogenetic aberrations on mesenchymal stem cells (MSC) from myelodysplastic syndrome (MDS) patients is controversial. The aim of the study is to characterize bone marrow (BM) derived MSC from patients with MDS using: kinetic studies, immunophenotyping, fluorescent in situ hybridization (FISH) and genetic changes by array-based comparative genomic hybridization (array-CGH). In all 36 cases of untreated MDS were studied. MDS-MSC achieved confluence at a significantly slower rate than donor-MSC, and the antigenic expression of CD105 and CD104 was lower. Array-CGH studies showed DNA genomic changes that were proved not to be somatic. These results were confirmed by FISH. To confirm that genomic changes were also present in freshly obtained MSCs they were enriched by sorting BM cells with the following phenotype: CD45(-)/CD73(++)/CD34(-)/CD271(++). They also showed genomic changes that were confirmed by FISH. To analyze the relationship of these aberrations with clinical-biological data an unsupervised hierarchical cluster analysis was performed, two clusters were identified: the first one included the 5q- syndrome patients, whereas the other incorporated other MDS. Our results show, for the first time that MSC from MDS display genomic aberrations, assessed by array-CGH and FISH, some of them specially linked to a particular MDS subtype, the 5q- syndrome.

In leukapheresis products from non-Hodgkin's lymphoma patients, the immature hematopoietic progenitors show higher CD90 and CD34 antigenic expression.

Damage to the stem cell progenitors caused by the chemotherapy received in patients diagnosed with non-Hodgkin's lymphoma (NHL) may be an important factor limiting progenitor cell mobilization. The aim of the present analysis was to evaluate the effect of the chemotherapy on the different progenitor cell subpopulations obtained in the leukapheresis. For this purpose, a combination of immunophenotype and functional assays has been performed in 26 mobilized peripheral blood (PB) samples from NHL patients and 36 healthy donors. The different progenitor subpopulations analyzed by flow cytometry significantly correlated with the corresponding populations assessed by functional assays in both healthy donors and NHL patients (p<0.05, r>0.5). The number of committed CFU-GM was similar in both groups (p=0.246), but we found significant decrease in the number of BFU-E and more immature progenitors in PB from NHL patients as compared to donors (p<0.05). Moreover, the number of total CFU was significantly lower in NHL patients (p=0.007). Accordingly, CD34+ cells (p=0.018) and CD34+ subpopulations was decreased in NHL patients. Nevertheless, CD90 and CD34 intensity was significantly higher within CD34+ cells from NHL patients as compared to donors. However, although numerically reduced non-committed CD34+ cells are more immature in chemotherapy mobilized NHL patients. In summary, our results show that all NHL hematopoietic progenitors, analyzed by both immunophenotypical and functional approaches, are impaired in leukapheresis products.

Angiogénesis terapéutica en pacientes con isquemia crítica crónica de las extremidades inferiores. Estudio fase II mediante inyección de células AC133+ obtenidas de sangre periférica movilizadas con G-CSF. Seguimiento de tres primeros casos / Therapeutical angiogenesis in patients with critical leg ischemia. Phase II study with injection of AC133+ cells mobilized with G-CSF from peripheral blood. Follow-up of three first cases

Introducción: La insuficiencia arterial crónica de las extremidades inferiores es una enfermedad extremadamente incapacitante y que afecta un 3,5% de los varones mayores de 60 años. En el momento actual, la terapia celular es una alternativa de reciente aplicación que presenta grandes perspectivas en el tratamiento de las isquemias periféricas. El objetivo del presente estudio fue analizar la seguridad y eficacia de las células AC133+ autólogas en promover la revascularización de MMII en pacientes con isquemia crítica de las EEII. Material y Métodos: Se han incluido 3 pacientes con isquemia crítica de las extremidades inferiores que fueron sometidos a movilización de células hematopoyéticas desde la médula osea a la sangre periferica (SP) a través del G-CSF. Posteriormente, los progenitores endoteliales autólogos AC133+, extraídos y seleccionados desde SP mediante el sistema CliniMACS® (Miltenyi Biotec), fueron inyectados intramuscularmente. Se hizo un seguimiento de los pacientes durante 6 meses según el protocolo del estudio, valorándose variables clínicas, funcionales, hemodinámicas, anatómicas y de calidad de vida. Resultados: El proceso de movilización, recolección y infusión de los progenitores endoteliales fue bien tolerado. A lo largo del seguimiento no se ha producido ninguna amputación y hubo mejoría objetiva y subjetiva de algunas de las variables estudiadas. Conclusión: Hasta el momento y con tres enfermos incluidos en el estudio el proceso de administración de las células AC133+ se ha mostrado seguro y sin complicaciones, entretanto hemos de ser prudentes en correlacionar la terapia celular y mejoría clínica. Con la inclusión de nuevos pacientes y su seguimiento a medio plazo seguramente se nos aclarará el efecto clínico de las células AC133+

Introduction: Chronical arterial disease (CAD) is an extremely incapacitating illness which affects 3-5% of the male population above 60 years-old. Actually, cell therapy is an alternative that causes great expectation for the treatment of the peripheral ischemias. The aim of the present study was to analyze the efficiency and security of autologous AC133+ cells on promoting limb revascularization in patients with critical CAD. Material and Methods: Three patients with critical CAD were included and followed up to date. The patients were subjected to mobilization of hematopoietic precursors from the bone marrow to peripheral blood with G-CSF. Later, the autologous endothelial stem cells AC133+, extracted and selected from blood through the CliniMACS® (Miltenyi Biotec) system, were injected intramuscularly. The patients were followed for 6 months as the study’s protocol and clinical, functional, hemodynamic, anatomical and quality of life variables were evaluated. Results: The process of mobilization, collection and infusion of the endothelial stem cells was well tolerated. Through the follow-up there were no amputations and there was objective as well as subjective improvement of some studied variables. Conclusion: So far and with three included patients, the process of administration of the AC133+ cells has shown security and lack of complication, although we have to be cautious on correlating cell therapy with clinical improvement. With the inclusion of new patients and their mid term follow-up we shall clarify the clinical effect of the AC133+ cells

Short-term endothelial progenitor cell colonies are composed of monocytes and do not acquire endothelial markers.

BACKGROUND: The aim of this study was to identify circulating endothelial progenitor cells (EPC) with colony-forming capacity and compare them with the monocytic-macrophage lineage. METHODS: Forty-two healthy donors were analyzed. EPC were cultured with VEGF and b-FGF. Sequential studies were performed on days +7 (colonies) +21 and +35. Monocytic cells were cultured using the same conditions as EPC until day +21 or alternatively by adding IGF. RESULTS: The number of EPC colonies was higher in BM than in mobilized or steady-state PB. Using EPC medium, monocytic cells formed cord-like structures but no colonies. However, colonies grew when IGF was added to the medium. By immunocytochemistry, colonies showed CD45, CD31 and lysozyme but no vWF. Colonies were CD4+, CD13+dim, CD14+, CD15++, CD16-/+dim, CD31+dim, CD33+dim, CD45+, CD105-/+dim, lysozyme+ and VE-cadherin+, and constantly negative for CD34, CD133 and KDR, when flow cytometry was used. The immunophenotype of pre-cultured and cultured monocytes was similar to that described for EPC. DISCUSSION: Our results suggest that the so-called 'EPC' obtained at 7 days of culture belong to the monocyte-macrophage lineage, as they share immunophenotypic and molecular features.

Effect of cumulative etoposide doses on the outcome of autologous peripheral-blood progenitor-cell transplantation for lymphoma.

Studies evaluating the effects of previous chemotherapy on stem-cell yield and hematological recovery after autologous peripheral-blood progenitor-cell transplantation (PBPCT) have shown conflicting results. We have retrospectively analyzed 103 consecutive lymphoma patients treated with the BEAM regimen and autologous PBPCT. The impact of the different chemotherapeutic drugs (cumulative doses) on stem-cell yield and transplant-related toxicity was investigated. Highly significant differences in platelet recovery (>20 x 10(9)/l) were observed between patients receiving less or more than 750 mg/m(2) of etoposide before transplant (15 vs 29 days, P=0.001), and between patients receiving less or more than 1.2 x 10(6)/kg CD34(+) cells (27 vs 14 days, P<0.001). Differences in neutrophil engraftment between groups were not clinically significant. Pre-transplant cumulative doses of etoposide >750 mg/m(2) were associated with low CD34(+) cell collections on multivariate analysis. The actuarial incidence of transplant-related mortality (TRM) was 14% at 5 years. Pre-transplant cumulative doses of etoposide >350 mg/m(2) and previous administration of procarbazine were found to be independent prognostic factors for TRM.

Peripheral blood is safer than bone marrow as a source of hematopoietic progenitors in patients with myelodysplastic syndromes who receive an allogeneic transplantation. Results from the Spanish registry.

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative therapy for patients with myelodysplastic syndromes (MDSs). We have analyzed the outcome of 81 patients who underwent an allogeneic transplant from an HLA-identical sibling donor. The overall survival (OS) was 31% and disease-free survival was 30% at 5.8 years. Transplant-related complications were the cause of death in 44% and disease progression in 16% of patients. Acute graft-versus-host disease (aGVHD) grades II-IV occurred in 32 cases (39%). Extensive chronic GVHD (cGVHD) was observed in 27% of patients. When the log-rank test was performed, we observed that patients transplanted more than 6 months after diagnosis, and those transplanted with bone marrow (BM) displayed a shorter survival (P=0.009 and 0.005, respectively). Patients who developed cGVHD showed a trend towards better OS (P=0.07). Patients receiving BM had a higher incidence of aGVHD (65 vs 50%) and less cGVHD (52 vs 30%), although the differences did not reach statistical significance. Moreover, patients who received PB-HSC displayed a faster engraftment (P=0.000) and showed a significantly lower early transplant-related mortality (14 vs 42%; P=0.006) and longer OS (P=0.005). In summary, our results show that hematopoietic transplantation should be performed as soon as possible in MDS patients and that PB is preferable to BM as a source of HSC.

Continuous oral cytarabine ocfosfate with interferon-alpha-2b for patients with newly diagnosed chronic myeloid leukaemia: a pilot study.

Recombinant(R) interferon alpha (r-IFN-alpha) has been shown to be an effective drug for chronic myeloid leukaemia (CML). However, higher response rates can be achieved using cytarabine along with r-IFN-alpha. YNK01 is a derivative of cytosine arabinoside for oral administration. So far, the only published experience with continuous YNK01 was in advanced CML (10 cases). We have performed a pilot study to evaluate the efficacy and toxicity of the combined therapy r-IFN-alpha and daily oral YNK01 in patients with newly diagnosed Ph+ CML. Ten previously untreated patients were included in the study. Among those patients evaluable for cytogenetic response, 87% (seven out of eight) reached a major cytogenetic response with four reaching complete cytogenetic response (50%). The most significant side-effects were gastrointestinal. Macrocytic anaemia was observed in three patients. In conclusion, continuous oral administration of YNK01 in combination with IFN-alpha is safe and can result in high-cytogenetic response rates.

Pathologic rupture of the spleen during induction with ATRA in a patient with acute promyelocytic leukemia.

Pathological rupture of the spleen is a rare but well recognized complication in hematological malignancies. Early clinical recognition of this life-threatening complication is necessary for rapid intervention. Here, we report on the case of a 26-year-old woman with acute promyelocytic leukemia who presented rupture of the spleen on day +2 of treatment with ATRA plus idarrubicin. In patients with acute leukemia, the presence of a painful abdomen and a sudden drop in hemoglobin levels, should alert of a possible splenic rupture, even without additional symptoms. This would facilitate an early treatment intervention with no modification to the chemotherapy schedule.

Clinical, hematological and cytogenetic characteristics of atypical chronic myeloid leukemia.

BACKGROUND: Atypical chronic myeloid leukemia (aCML) is an infrequent chronic myeloproliferative disorder characterized by leukocytosis, absence of Philadelphia chromosome or BCR-ABL rearrangement, and marked myeloid dysplasia. Some cases have an absolute monocytosis but can be distinguished from chronic myelomonocytic leukemia (CMML) by the presence of a higher percentage (> 15%) of circulating immature granulocytes. PATIENTS AND METHODS: In a series of 11 patients with a diagnosis of aCML according to the FAB proposals we have analyzed the most relevant clinical, hematological and cytogenetic characteristics. RESULTS: The median age was 65 years (16-84). All but one case showed, at time of diagnosis, leukocytosis (median WBC was 36 x 10(9)/l), 55% had moderate anemia and 36% had thrombocytopenia. Most cases had marked dysplasia, particularly in the granulocytic lineage (82% of the cases), and all cases showed bone marrow red hypoplasia. Cytogenetic abnormalities were present in 9 out of the 11 patients. Trisomy 8 was observed in three cases and other clonal chromosomal abnormalities included deletions of 5q, 13q, 17p, 12q, and 11q as well as a t(6;8)(p23;q22) translocation. Fluorescence in situ hybridization (FISH) studies failed to demonstrate ETV-6 gene involvement. The median survival time from diagnosis was only 14 months (range 3-56 months). CONCLUSIONS: These data suggest that aCML is a rare disease which is characterized by leukocytosis, with dysgranulopoiesis, BM erythroid hypoplasia, chromosomal, though not recurrent, abnormalities and poor prognosis.

Intra-muscular vidarabine therapy for polyomavirus-associated hemorrhagic cystitis following allogeneic hemopoietic stem cell transplantation.

Hemorrhagic cystitis (HC) is a common complication following hemopoietic stem cell transplantation (HSCT), its incidence ranging from 7 to 52% of all patients. Late occurring HC frequently results from viral infections. We describe a patient who developed severe polyomavirus-associated HC, which responded dramatically to a single dose of intra-muscular vidarabine. Previous studies show an improvement in HC with vidarabine therapy, but to date only the intravenous route of administration has been described and responses described take from several days to weeks. This report confirms the safety and efficacy of vidarabine administered intramuscularly when used in patients with an adequate platelet count, thereby making its use feasible when intravenous vidarabine is not available.

Factors that influence long-term hematopoietic function following autologous stem cell transplantation.

The aim of the present study was to assess which factors influence hematopoietic function long term after transplantation. For this purpose, we have analyzed a series of 79 patients who underwent autologous transplantation. None of them received any further chemotherapy or radiotherapy after transplant. All patients were disease-free 1 year after autologous transplantation. Late impairment of hematopoietic function was defined as the presence of non-transient peripheral blood cytopenias, detected 6 and 12 months after autografting. Before transplantation, 38.7% of patients showed peripheral blood cytopenias. Six and 12 months after transplantation, cytopenias presented in 44.2% and 42.4% of patients, respectively. Cases displaying cytopenias 6 months after transplantation had received a significantly lower dose of CFU-GM and CD34+ cells than patients without cytopenias (P = 0.012 and P = 0.04, respectively). The same correlation, with even higher statistical significance, was observed 12 months after transplant (P = 0.007 and P = 0.005). Alkylating agents and radiotherapy administered prior to transplantation and age did not seem to influence the presence of permanent cytopenias. The incidence did not vary significantly according to the stem cell source (bone marrow or peripheral blood). The number of CFU-GM and CD34+ cells infused was the most important factor for maintenance of adequate hematopoiesis.