Amaya Zabalza

Haplo-Cord transplantation compared to haploidentical transplantation with post-transplant cyclophosphamide in patients with AML

For patients with AML, the best alternative donor remains to be defined. We analyze outcomes of patients who underwent myeloablative umbilical cord blood or haploidentical hemopoietic stem cell transplantation (HSCT) in Spain. Fifty-one patients underwent single umbilical cord blood transplantation supported by a third party donor (Haplo-Cord) between 1999 and 2012, and 36 patients received an haploidentical HSCT with post-transplant cyclophosphamide (PTCY–haplo) between 2012 and 2014 in GETH centers. The Haplo-Cord cohort included a higher proportion of patients with high disease risk index and use of TBI in the conditioning regimen, and hematopoietic cell transplantation–age Comorbidity Age Index was higher in PTCY–haplo patients. Cumulative incidence of neutrophil engraftment was 97% in the Haplo-Cord and 100% in the PTCY–haplo group, achieved in a median of 12 and 17 days, respectively (P=0.01). Grade II–IV acute GvHD rate was significantly higher in the PTCY–haplo group (9.8% vs 29%, P=0.02) as well as chronic GvHD rates (20% vs 38%, P=0.03). With a median follow-up of 61 months for the Haplo-Cord group and 26 months for the PTCY–haplo cohort, overall survival at 2 years was 55% and 59% (P=0.66), event-free survival was 45% vs 56% (P=0.46), relapse rate was 27% vs 21% (P=0.79), and non-relapse mortality was 17% vs 23% (P=0.54), respectively. In this multicenter experience, Haplo-Cord and PTCY–haplo HSCT offer valid alternatives for patients with AML. Neutrophil engraftment was faster in the Haplo-Cord cohort, with similar survival rates, with higher GvHD rates after haploidentical HSCT.

Mobilization of hematopoietic progenitor cells from allogeneic healthy donors using a new biosimilar G‐CSF (Zarzio®)

Peripheral blood progenitor cells (PBPCs) have become the major source of hematopoietic progenitor cells for allogeneic transplantation. In February 2008, Zarzio® was approved by the European Medicine Agency for PBPCs mobilization, but this authorization was not based in trials analyzing safety and efficacy for PBPCs mobilization. Since August 2011, Zarzio® has been used at our institution for PBPCs mobilization. In total 36 healthy family donors underwent PBPCs mobilization, 18 with Neupogen® and 18 with Zarzio®. Donor characteristics were equivalent between groups, and no severe adverse effects were registered in the Zarzio® group. The number of CD34 cells collected/Kg recipient body weight was 6.7 × 106 (3.8–11.1) in the Zarzio® group versus 8.4 × 106 (5.6–16.6) in the Neupogen® group (P = 0.04). We collected the minimal target cell dose (2 × 106/kg) in all donors from each group and no significant differences were found in the collection of the optimal cell dose (5 × 106/kg) between groups, although 3/18 (16.6%) donors that received Zarzio® failed to mobilize the optimal cell dose compared with 0% in the Neupogen® group. A total of 35 patients proceeded to transplantation (17 in the Zarzio® and 18 in the Neupogen® groups, respectively). Platelet and neutrophil median time to engraftment was comparable between the two groups. Our retrospective study supports the conclusion that Zarzio® mobilization of PBPCs in healthy donors is safe but perhaps not as effective as the reference Neupogen. However, more prospective trials are required to definitively asses the safety and efficacy of G‐CSF biosimilars for PBPCs mobilization in healthy donors. J. Clin. Apheresis 31:48–52, 2016.

Streptamer technology allows accurate and specific detection of CMV-specific HLA-A*02 CD8(+) T cells by flow cytometry.

Multimer technology is widely used to screen antigen‐specific immune recovery after allogeneic hematopoietic stem cell transplantation (allo‐HSCT) as it enables identification, enumeration, phenotypic characterization and isolation of virus‐specific T‐cells. Novel approaches of multimerization might improve on classical tetramer staining; however, their use as standard monitoring technique to quantify antigen‐specific cells has not been validated yet. We have compared two of these available multimeric complexes: pentamer and streptamer to select the best strategy for the incorporation into clinical monitoring practice.

Assessment of the effector function of CMV-specific CTLs isolated using MHC-multimers from granulocyte-colony stimulating factor mobilized peripheral blood

BackgroundAdoptive transfer of CMV-specific T cells has shown promising results in preventing pathological effects caused by opportunistic CMV infection in immunocompromised patients following allogeneic hematopoietic stem cell transplantation. The majority of studies have used steady-state leukapheresis for CMV-reactive product manufacture, a collection obtained prior to or months after G-CSF mobilization, but the procurement of this additional sample is often not available in the unrelated donor setting. If the cellular product for adoptive immunotherapy could be generated from the same G-CSF mobilized collection, the problems associated with the additional harvest could be overcome. Despite the tolerogenic effects associated with G-CSF mobilization, recent studies described that CMV-primed T cells generated from mobilized donors remain functional.MethodsMHC-multimers are potent tools that allow the rapid production of antigen-specific CTLs. Therefore, in the present study we have assessed the feasibility and efficacy of CMV-specific CTL manufacture from G-CSF mobilized apheresis using MHC-multimers.ResultsCMV-specific CTLs can be efficiently isolated from G-CSF mobilized samples with Streptamers and are able to express activation markers and produce cytokines in response to antigenic stimulation. However, this anti-viral functionality is moderately reduced when compared to non-mobilized products.ConclusionsThe translation of Streptamer technology for the isolation of anti-viral CTLs from G-CSF mobilized PBMCs into clinical practice would widen the number of patients that could benefit from this therapeutic strategy, although our results need to be taken into consideration before the infusion of antigen-specific T cells obtained from G-CSF mobilized samples.

Voriconazole and its clinical potential in the prophylaxis of systemic fungal infection in patients with hematologic malignancies: a perspective review.

Invasive fungal infections (IFIs) have become high prevalence in patients with hematologic malignancies. Drug-based strategies for IFIs include various approaches such as prophylactic, empiric, preemptive, and directed treatment. Prophylaxis is an attractive strategy in high-risk patients, given the lack of reliable diagnostics and the high mortality rate associated with IFIs. Prophylaxis includes the use of antifungal drugs in all patients at risk. An ideal antifungal compound for prophylaxis should have a potent and broad activity, be available both orally and intravenously, and have a low toxicity profile. Voriconazole fulfills all these criteria. The clinical efficacy of voriconazole against the majority of fungal pathogens makes it potentially very useful for the prevention of IFIs in patients with hematologic malignancies. Voriconazole appears to be very effective for the primary and secondary prevention of IFIs in these patients and recipients of allogeneic hematopoietic stem-cell transplantation. Randomized controlled trials evaluating voriconazole as primary antifungal prophylaxis in patients with neutropenia treated for a variety of hematologic malignancies have been performed, confirming its value as a prophylactic agent. Voriconazole is generally safe and well tolerated; however, its use is also associated with a number of concerns. In most patients with hematologic malignancies there is the potential for pharmacokinetic drug–drug interactions given that voriconazole is metabolized through the P450 cytochrome system.

Functional specific-T-cell expansion after first cytomegalovirus reactivation predicts viremia control in allogeneic hematopoietic stem cell transplant recipients

The use of preemptive antiviral therapy to prevent cytomegalovirus (CMV) disease in allogeneic hematopoietic stem cell transplantation (allo‐HSCT) recipients might result in over‐treatment, inducing drug‐related toxicity and viral resistance. A search for predictive markers is needed to determine requirement for antiviral therapy. Clinical follow‐up, in combination with the use of streptamers (STs) and cytokine‐intracellular staining, could help to identify patients at high risk for CMV reactivations. To study the immune response and reactivation control by CMV‐specific CD8+ T‐cell (CMV‐CTL) populations, we monitored 25 patients who have undergone allo‐HSCT by using ST multimer and intracellular cytokine staining. Our study has revealed that the presence of functional CMV‐specific T cells, determined by early interferon γ production or by significant T‐cell expansion after first CMV reactivation, correlated with short CMV viremia duration and low number of CMV reactivations. By contrast, the absence of functional CMV‐CTLs does correlate with CMV recurrence. These results support that behavior of CMV‐specific subpopulations after reactivation influences reactivations and can guide preemptive therapy.

CMV-specific T cell isolation from G-CSF mobilized peripheral blood: depletion of myeloid progenitors eliminates non-specific binding of MHC-multimers

BackgroundCytomegalovirus (CMV)-specific T cell infusion to immunocompromised patients following allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT) is able to induce a successful anti-viral response. These cells have classically been manufactured from steady-state apheresis samples collected from the donor in an additional harvest prior to G-CSF mobilization, treatment that induces hematopoietic stem cell (HSC) mobilization to the periphery. However, two closely-timed cellular collections are not usually available in the unrelated donor setting, which limits the accessibility of anti-viral cells for adoptive immunotherapy. CMV-specific cytotoxic T cell (CTL) manufacture from the same G-CSF mobilized donor stem cell harvest offers great regulatory advantages, but the isolation using MHC-multimers is hampered by the high non-specific binding to myeloid progenitors, which reduces the purity of the cellular product.MethodsIn the present study we describe an easy and fast method based on plastic adherence to remove myeloid cell subsets from 11 G-CSF mobilized donor samples. CMV-specific CTLs were isolated from the non-adherent fraction using pentamers and purity and yield of the process were compared to products obtained from unmanipulated samples.ResultsAfter the elimination of unwanted cell subtypes, non-specific binding of pentamers was notably reduced. Accordingly, following the isolation process the purity of the obtained cellular product was significantly improved.ConclusionsG-CSF mobilized leukapheresis samples can successfully be used to isolate antigen-specific T cells with MHC-multimers to be adoptively transferred following allo-HSCT, widening the accessibility of this therapy in the unrelated donor setting. The combination of the clinically translatable plastic adherence process to the antigen-specific cell isolation using MHC-multimers improves the quality of the therapeutic cellular product, thereby reducing the clinical negative effects associated with undesired alloreactive cell infusion.

Combined Selection System to Lower the Cutoff for Plasma Cell Enrichment Applied to iFISH Analysis in Multiple Myeloma

Multiple myeloma (MM) is a very heterogeneous disease, characterized by multiple cytogenetic aberrations on plasma cells (PC) that have been traditionally used to predict the outcome of the disease. A mayor issue on the analysis of PC is the sometimes low infiltration of these cells in the bone marrow that hampers cytogenetic studies. To solve this problem we have optimized a selection strategy based on PC immunomagnetic isolation that has allowed us to lower to 1% the minimal PC infiltration requirement without loss of purity, enabling to perform genetic analysis. In this study, we have analyzed 153 bone marrow samples of patients suspected of MM, collected from February 2015 to May 2017 by the Genetics service of the Complejo Hospitalario de Navarra. Clinical characteristics of the patients and PC immunophenotyping, conventional cytogenetics and interphase fluorescence in situ hybridization (iFISH) analyses have been assessed on these samples. In our cohort 90% of the samples had cytogenetic abnormalities, among them 50% presented immunoglobulin rearrangements, 41.9% showed 1q gains, 29.7% showed 1p deletions and 33% presented TP53 deletion.

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

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.