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Summary. Circulating monocytes from multiple myeloma patients enrolled in a clinical study of anti-idiotype vaccination were labelled with clinical-grade anti-CD14 microbeads and positively selected with the CliniMACS instrument. Cells were then grown, according to good manufacturing practice guidelines, in fetal-calf-serum-free medium in cell culture bags and differentiated to dendritic cells (DC) with granulocyte–macrophage colony stimulating factor plus interleukin 4 (IL-4), followed by either tumour necrosis factor-α (TNF-α) or a cocktail of IL-1β, IL-6, TNF-α and prostaglandin-E2 . The CD14+ cell yield was increased from 17·6 ± 6·5% to 93·8 ± 6·3% (recovery 64·4 ± 15·4%, viability > 97%). After cell culture, phenotypic analysis showed that 86·7 ± 6·8% of the cells were DC: 2·27 ± 0·9 × 108 DC/leukapheresis were obtained, which represented 20·7 ± 4·6% of the initial number of CD14+ cells. Notably, the cytokine cocktail induced a significantly higher percentage and yield (28·6 ± 3% of initial CD14+ cells) of DC than TNF-α alone, with secretion of larger amounts of IL-12, potent stimulatory activity on allogeneic T cells and efficient presentation of tumour idiotype to autologous T cells. Storage in liquid nitrogen did not modify the phenotype or functional characteristics of preloaded DC. The recovery of thawed, viable DC was 78 ± 10%. Finally, interferon-α-2b was at least as efficient as IL-4 in inducing the differentiation of mature, functional DC from monocytes. [ABSTRACT FROM AUTHOR]

The feasibility of sequential positive and negative selection of mobilized CD34+ B-lineage negative cells to achieve tumour-free autografts in multiple myeloma (MM) patients was evaluated. Peripheral blood stem cells (PBSC) of 14 patients with advanced disease were mobilized. CD34+ cells were enriched in 12 of the patients by the avidin–biotin immunoabsorption technique. Subsequently, CD10+, CD19+, CD20+ and CD56+ cells (B-lin cells) were removed by immunomagnetic depletion. Minimal residual disease (MRD) was detected by flow cytometry and PCR-based molecular analysis of the patient specific IgH complementary-determining region III (CDRIII). Positive selection of stem cells produced a median recovery of 54.7% of the initial content of CD34+ cells (median purity 71.9%). Negative depletion of B-lineage cells reduced the number of CD34+ cells to 33.3% of the baseline value (median purity 72.7%). However, long-term culture assays showed the recovery of >60% of primitive haemopoietic progenitor cells after depletion of the B-lineage-positive cells. All evaluable patients had detectable disease in PBSC collections. The first step of positive selection of CD34+ cells resulted in >2 logs of tumour cell purging. However, molecular assessment showed the persistence of the disease in 6/7 cases. Immunofluorescence analysis demonstrated 1 additional log of B-cell purging by negative depletion. More importantly, molecular evaluation of IgH CDRIII region showed the disappearance of myeloma cells in 6/7 patients. 12 patients received a median of 3.9 × 106 CD34+ B-lin- cells/kg after conditioning with high-dose melphalan and showed a rapid reconstitution of haemopoiesis. These results were similar to two similar cohorts of patients who received either unmanipulated PBSC or positively selected CD34+ cells after the same... [ABSTRACT FROM AUTHOR]

The monoclonal antibody 8A, which recognizes a human plasma cell-associated antigen, was covalently linked to xanthine oxidase in a conjugate maintaining both immunological and enzymatic properties. A significant degree of target cell lysis was obtained at an enzyme concentration that was ineffective on non-target cells and on myeloid staminal cells (CFU-GM). The cytotoxic activity was abolished by an excess of antibody, by allopurinol and by superoxide dismutase and catalase. A possible use of the conjugate for bone marrow purging in multiple myeloma patients is suggested. [ABSTRACT FROM AUTHOR]

Abstract: We assessed the capacity of positively selected autologous CD133+ hematopoietic stem cells (HSCs) to reconstitute lymphomyelopoiesis in chronic lymphocytic leukemia (CLL) patients receiving myeloablative chemotherapy. Ten resistant/relapsed CLL patients underwent HSC mobilization with chemotherapy and granulocyte-colony stimulating factor (G-CSF). Positive selection of circulating CD133+ HSCs was performed by immunomagnetic technique. Highly purified HSCs were reinfused after busulphan/melphalan myeloablative treatment. A median number of 4.2 × 106 CD34+ cells/kg and of 3.14 × 106 CD133+ cells/kg were collected. Immunomagnetic selection resulted in the reinfusion of a median number of 2.45 × 106 CD133+ cells/kg (median purity: 94.8%; median recovery: 84%) and 2.4 × 106 CD34+ cells/kg (median purity: 93%; median recovery: 71%). HSC selection resulted in a median T cell and CD19+/CD5+ cell depletion of 3.85 log and 2.8 log, respectively. At the molecular level, however, 7 of 8 valuable purified HSC fractions were contaminated by leukemic cells. All CLL patients showed rapid and sustained myeloid engraftment after reinfusion of purified CD133+ cells. Immunologic reconstitution was comparable to that routinely observed in patients reinfused with unmanipulated leukapheresis products and no late infectious complications were observed. With a median follow-up of 28 months for transplanted patients, 5 patients are in clinical complete remission, 3 are in partial remission, and 1 is in progression. In conclusion, the reinfusion of highly purified CD133+ HSCs allowed the rapid and sustained recovery of hematopoiesis after myeloablative treatment in resistant/relapsed CLL patients. However, the purging potential of positive selection of CD133+ cells is not adequate to achieve tumor-free autografts. [Copyright &y& Elsevier]

: ObjectiveThe immunogenic role of human CD34+ cells in allogeneic hematopoietic stem cell transplantation is controversial. In this study we tested the role of CD40 and CTLA4 ligands on CD34+ cell costimulation of HLA-mismatched lymphocytes.: Materials and MethodsAn anti-CD40L monoclonal antibody (hu5C8) and/or CTLA4-Ig molecule were used in primary mixed lymphocyte culture (MLC) with irradiated CD34+ blood cells and allogeneic responders. Then, secondary MLC, cytotoxic activity, and effector cytokine expression and production were measured.: ResultsEach reagent was able to reduce anti-CD34+ cell alloreactivity, but only the combination of the anti-CD40L monoclonal antibody and CTLA4-Ig induced greater than 90% inhibition of T-cell response in primary MLC and prevented generation of cytotoxic T cells when priming with purified CD34+ cells. Importantly, responder cells activated by allogeneic CD34+ cells in the presence of anti-CD40L monoclonal antibody and CTLA4-Ig entered a state of antigen-specific unresponsiveness while responding to third party antigen, tetanus toxoid, or phytohemagglutinin, and showed suppression of interferon-γ and increase of interleukin-10 expression and release. Interestingly, addition of interleukin-2 in secondary MLC did not reverse T-cell anergy.: ConclusionsThe results demonstrate that human CD34+ blood progenitors stimulate T-cell responses potently and can induce T-cell unresponsiveness only when both B7:CD28 and CD40:CD40L pathways are blocked, with an increase of interleukin-10–producing cells. Therefore, our data allow design of in vivo studies aimed at achieving T-cell tolerance across HLA barriers by using purified CD34+ cells and costimulatory blockade. [Copyright &y& Elsevier]

Busulfan liver metabolism depends on glutathione, a crucial mediator of cellular and systemic stress. Here we investigated 40 polymorphisms at 27 loci involved in hepatic glutathione homeostasis, with the aim of testing their impact on the clinical outcome of 185 busulfan-conditioned allogeneic transplants. GSTA2 S112T serine allele homozygosity is an independent prognostic factor for poorer survival (RR=2.388), for increased any time- and 100-day transplant-related mortality (RR=4.912 and RR=5.185, respectively). The genotype also predicts a wider busulfan area under the concentration-time curve (1214.36 ± 570.06 vs. 838.10 ± 282.40 mMol*min) and higher post-transplant bilirubin serum levels (3.280 ± 0.422 vs. 1.874+0.197 mg/dL). In vitro, busulfan elicits pro-inflammatory activation (increased NF-KappaB activity and interleukin-8 expression) in human hepatoma cells. At the same time, the drug down-regulates a variety of genes involved in bilirubin liver clearance: constitutive androstane receptor, multidrug resistance-associated protein, solute carrier organic anion transporters, and even GSTA2. It is worthy of note that GSTA2 also acts as an intra-hepatic bilirubin binding protein. These data underline the prognostic value of GSTA2 genetic variability in busulfan-conditioned allotransplants and suggest a patho-physiological model in which busulfan-induced inflammation leads to the impairment of post-transplant bilirubin metabolism.

Background and Objectives: The aim of this study was to evaluate the efficacy of pegfilgrastim, in combination with salvage chemotherapy, in mobilizing CD34(+) stem cells into the peripheral blood of pretreated lymphoma patients., Design and Methods: This was an open-label phase II study including 25 pretreated patients (Hodgkin's disease=4; aggressive non-Hodgkin's lymphoma=21). The primary end-point of the study was the successful mobilization of a target cell dose of 2x10(6) CD34(+) cells/kg in lymphoma patients receiving ifosfamide, epirubicin and etoposide (IEV) chemotherapy and a fixed dose (6 mg) of pegfilgrastim given as single subcutaneous injection., Results: Following chemotherapy, all patients had grade 4 neutropenia that lasted a median of 1.5 days (1-3). Pegfilgrastim treatment was well tolerated and only 2/25 patients required pain-control medication. CD34+ cells were mobilized in all patients. The median (range) peak value of peripheral blood CD34+ cells after IEV chemotherapy and pegfilgrastim was 141x10(6)/L (12.8-386) and occurred almost invariably on day +14 (13-16). Twenty-three of the 25 patients underwent a single standard volume leukapheresis to collect a median of 8.7x10(6) CD34(+) cells/kg (1.78-17.3). Twenty four/25 patients (96%) reached the target cell dose of 2x10(6) CD34(+) cells/kg. High concentrations of circulating CD34+ cells (> 50x10(6)/L) were observed for several days after the achievement of the peak value. All the study patients were transplanted with their pegfilgrastim-mobilized CD34(+) cells and showed a rapid and sustained engraftment after high-dose chemotherapy., Interpretation and Conclusions: Our results show that pegfilgrastim as an adjunct to chemotherapy is a predictable and highly effective mobilization regimen in pretreated lymphoma patients.

Background and Objectives: In this work we examine the characteristics and outcome of patients with Hodgkin's disease (HD) treated with high-dose therapy (HDT) and autologous transplantation at our Institute between 1982 to 2000., Design and Methods: A retrospective analysis was performed examining patients' characteristics, prior chemotherapy regimens, pre-transplant disease status, HDT regimen, source of stem cells, time for hematopoietic recovery, complications of transplantation, response rates, overall survival (OS) and relapse-free survival (RFS)., Results: Ninety-seven patients with HD were treated and had estimated 10-year OS and RFS rates of 32% and 60%, respectively. Disease status (sensitive vs. refractory) before HDT was the most powerful predictive parameter for OS and RFS in both univariate and multivariate analyses. The rate of transplant-related mortality in the whole cohort was only 1% whereas the rate of second malignancies was 3%., Interpretation and Conclusions: Our results confirm that HDT with autologous transplantation is associated with a durable RFS in a remarkable proportion of HD patients and that the procedure has a very low global early and late toxicity.