Christian Beck

Bio: Christian Beck is an academic researcher from Heidelberg University. The author has contributed to research in topics: Transplantation & Buffy coat. The author has an hindex of 7, co-authored 11 publications receiving 158 citations.

A novel method for simultaneous analysis of specific platelet antibodies: SASPA.

Abstract: Glycoprotein (GP)-specific platelet antibodies can cause allo-immune and auto-immune thrombocytopenia. The specific detection of relevant antibodies is a prerequisite for diagnosis and treatment. Here, we describe an improved method based on simultaneous detection of various platelet-specific immunoglobulin G (IgG) and IgM antibodies. Bead populations with distinct fluorescence intensities, coated with monoclonal antibodies specific for mouse heavy chain isotypes, were used for the simultaneous immobilization of platelet-GP [IIb/IIIa, Ib/IX, human leucocyte antigen (HLA) class I, or Ia/IIa, CD32, GPIV or CD109, Ib/IX, HLA class I]. In order to detect human IgG and IgM antibodies simultaneously, phycoerythrin- and fluorescein isotiocyanate-conjugated goat anti-human IgG and IgM were added. On this basis, the abundance of six distinct antibodies (three anti-GP, each with subclasses IgG and IgM) were simultaneously analysed without cross-reaction by flow cytometry. For evaluation, sera and platelets from 169 patients with platelet-binding and/or platelet-associated antibodies were investigated. The monoclonal antibody-specific immobilization of platelet antigen (MAIPA) assay was performed in parallel as reference test. The simultaneous analysis of platelet-specific antibodies (SASPA) assay was able to detect all platelet-specific IgG and IgM that were also recognized by MAIPA with a comparable sensitivity. SASPA proved to be a rapid and reliable assay that required less platelets than other methods. This method has the potential to pave the way for new investigations of platelet-specific antibodies.

Engraftment capacity of umbilical cord blood cells processed by either whole blood preparation or filtration

Abstract: Umbilical cord blood (UCB) preparation needs to be optimized in order to develop more simplified procedures for volume reduction, as well as to reduce the amount of contaminating cells within the final stem cell transplant. We evaluated a novel filter device (StemQuick™E) and compared it with our routine buffy coat (BC) preparation procedure for the enrichment of hematopoietic progenitor cells (HPCs). Two groups of single or pooled UCB units were filtered (each n = 6), or equally divided in two halves and processed by filtration and BC preparation in parallel (n = 10). The engraftment capacity of UCB samples processed by whole blood (WB) preparation was compared with paired samples processed by filtration in the nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse animal model. Filtration of UCB units in the two groups with a mean volume of 87.8 and 120.7 ml, respectively, and nucleated cell (NC) content of 9.7 and 23.8 × 108 resulted in a sufficient mean cell recovery for mononucleated cells ([MNCs] 74.2%-77.5%), CD34+ cells (76.3%-79.0%), and colony-forming cells (64.1%-86.3%). Moreover, we detected a relevant depletion of the transplants for RBCs (89.2%-90.0%) and platelets ([PLTs] 77.5%-86.1%). In contrast, the mean depletion rate using BC processing proved to be significantly different for PLTs (10%, p = 0.03) and RBCs (39.6%, p < 0.01). The NC composition showed a highly significant increase in MNCs and a decrease in granulocytes after filtration (p < 0.01), compared with a less significant MNC increase in the BC group (p < 0.05). For mice transplanted with WB-derived progenitors, we observed a mean of 15.3% ± 15.5% of human CD45+ cells within the BM compared with 19.9% ± 16.8% for mice transplanted with filter samples (p = 0.03). The mean percentage of human CD34+ cells was 4.2% ± 3.1% for WB samples and 4.5% ± 3.2% for filter samples (p = 0.68). As the data of NOD/SCID mice transplantation demonstrated a significant engraftment capacity of HPCs processed by filtration, no negative effect on the engraftment potential of filtered UCB cells versus non-volume-reduced cells from WB transplants was found. The StemQuick™E filter devices proved to be a useful tool for Good Manufacturing Practices conform enrichment of HPCs and MNCs out of UCB. Filtration enables a quick and standardized preparation of a volume-reduced UCB transplant, including a partial depletion of granulocytes, RBCs, and PLTs without the need for centrifugation. Therefore, it seems very probable that filter-processed UCB transplants will also result in sufficient hematopoietic reconstitution in humans.

Ofatumumab retreatment and maintenance in fludarabine-refractory chronic lymphocytic leukaemia patients.

Abstract: There are limited data on retreatment with monoclonal antibodies (mAb) in patients with chronic lymphocytic leukaemia (CLL). In a pivotal study, ofatumumab (human anti-CD20 mAb) monotherapy demonstrated a 47% objective response rate (ORR) in fludarabine refractory CLL patients. From this study, a subset of 29 patients who had at least stable disease and then progressed were retreated with eight weekly ofatumumab infusions (induction treatment period), followed by monthly infusions for up to 2years (maintenance treatment period). The ORR after 8weeks of induction retreatment was 45% and 24% had continued disease control after maintenance at 52weeks. Efficacy and safety of the retreated patients were compared with their initial results in the pivotal study. Response duration was 241months vs. 68months; time to next therapy was 148months vs. 123months; and progression-free survival was 74months vs. 79months (medians). Upon retreatment, 72% had infusion reactions, mostly Grade 1-2. Three patients had fatal infections. In summary, ofatumumab retreatment and maintenance therapy was feasible in patients with heavily pretreated CLL and appeared to result in more durable disease control than initial ofatumumab treatment in this subset of patients who may have a more favourable disease profile.

Myelodysplastic syndrome of donor origin subsequent to successful treatment of myeloid/NK-cell precursor leukaemia with allogeneic PBSCT : two very rare conditions in one patient

Abstract: We report a 36-year-old male with myeloid/natural killer (NK)-cell precursor acute leukaemia with a complex aberrant karyotype, who was treated according to an acute-myeloid-leukaemia (AML) treatment protocol (idarubicine, cytarabine, and etoposide) followed by high-dose cytarabine consolidation and achieved complete remission. He underwent allogeneic matched unrelated donor (MUD) peripheral blood stem-cell transplantation (PBSCT) and remained in remission throughout his remaining life. Seven months posttransplantation, a myelodysplastic syndrome (MDS) with (20q−) of donor origin was diagnosed causing severe thrombocytopenia and finally leading to infection and death. This patient represents one of the few cases published achieving remission for a significant period of time after being diagnosed with myeloid/NK-cell precursor acute leukaemia, a very rare malignant disease. We conclude, despite the fatal outcome due to infection, that allogeneic PBSCT is a therapeutic option for patients with this entity. In addition, the development of a myelodysplastic syndrome of donor origin is extremely rare and only very few cases are published worldwide.

Comparative analysis of mesenchymal stem cells from bone marrow, umbilical cord blood, or adipose tissue.

Abstract: Mesenchymal stem cells (MSCs) represent a promising tool for new clinical concepts in supporting cellular therapy. Bone marrow (BM) was the first source reported to contain MSCs. However, for clinical use, BM may be detrimental due to the highly invasive donation procedure and the decline in MSC number and differentiation potential with increasing age. More recently, umbilical cord blood (UCB), attainable by a less invasive method, was introduced as an alternative source for MSCs. Another promising source is adipose tissue (AT). We compared MSCs derived from these sources regarding morphology, the success rate of isolating MSCs, colony frequency, expansion potential, multiple differentiation capacity, and immune phenotype. No significant differences concerning the morphology and immune phenotype of the MSCs derived from these sources were obvious. Differences could be observed concerning the success rate of isolating MSCs, which was 100% for BM and AT, but only 63% for UCB. The colony frequency was lowest in UCB, whereas it was highest in AT. However, UCB-MSCs could be cultured longest and showed the highest proliferation capacity, whereas BM-MSCs possessed the shortest culture period and the lowest proliferation capacity. Most strikingly, UCB-MSCs showed no adipogenic differentiation capacity, in contrast to BM- and AT-MSCs. Both UCB and AT are attractive alternatives to BM in isolating MSC: AT as it contains MSCs at the highest frequency and UCB as it seems to be expandable to higher numbers.

The Myelodysplastic Syndromes: Diagnosis and Treatment

Abstract: The myelodysplastic syndromes (MDSs) are common, acquired, clinically challenging hematologic conditions that are characterized by bone marrow failure and a risk of progression to acute leukemia. These disorders can arise de novo, especially in elderly patients or, less often, as a consequence of prior chemotherapy or radiotherapy for an unrelated disease. The MDS classification systems were revised recently and updated. These refined classification and prognostic schemes help stratify patients by their risk of leukemia progression and death; this knowledge can help clinicians select appropriate therapy. Although many treatments for MDS have been proposed and evaluated, at present, only hematopoietic stem cell transplantation offers any real hope for cure, and no available therapy beyond general supportive care offers benefit to more than a minority of patients. However, recent clinical trials enrolling patients with MDS have reported encouraging results with use of newer drugs, including lenalidomide, decitabine, and darbepoetin alfa. Other exciting treatment regimens are being tested. Here, we present a contemporary, practical clinical approach to the diagnosis and risk-stratified treatment of MDS. We review when to suspect MDS, detail how to evaluate patients who may have a form of the condition, explain key features of treatments that are currently available in the United States, and summarize a general, common-sense therapeutic approach to patients with MDS.

British HIV Association guidelines for HIV-associated malignancies 2014

Abstract: M Bower, S Collins, C Cottrill, K Cwynarski, S Montoto, M Nelson, N Nwokolo, T Powles, J Stebbing, N Wales and A Webb, on behalf of the AIDS Malignancy Subcommittee Department of Oncology, Chelsea & Westminster Hospital, London, UK, HIV i-Base and UK-CAB, London, UK, St Bartholomew’s Hospital, London, UK, Royal Free Hospital, London, UK, Hammersmith Hospital, London, UK and Royal Sussex County Hospital, Brighton, UK

Clinical-grade generation of active NK cells from cord blood hematopoietic progenitor cells for immunotherapy using a closed-system culture process.

Abstract: Natural killer (NK) cell-based adoptive immunotherapy is a promising treatment approach for many cancers. However, development of protocols that provide large numbers of functional NK cells produced under GMP conditions are required to facilitate clinical studies. In this study, we translated our cytokine-based culture protocol for ex vivo expansion of NK cells from umbilical cord blood (UCB) hematopoietic stem cells into a fully closed, large-scale, cell culture bioprocess. We optimized enrichment of CD34+ cells from cryopreserved UCB units using the CliniMACS system followed by efficient expansion for 14 days in gas-permeable cell culture bags. Thereafter, expanded CD34+ UCB cells could be reproducibly amplified and differentiated into CD56+CD3− NK cell products using bioreactors with a mean expansion of more than 2,000 fold and a purity of >90%. Moreover, expansion in the bioreactor yielded a clinically relevant dose of NK cells (mean: 2×109 NK cells), which display high expression of activating NK receptors and cytolytic activity against K562. Finally, we established a versatile closed washing procedure resulting in optimal reduction of medium, serum and cytokines used in the cell culture process without changes in phenotype and cytotoxic activity. These results demonstrate that large numbers of UCB stem cell-derived NK cell products for adoptive immunotherapy can be produced in closed, large-scale bioreactors for the use in clinical trials.