A phase I study of paclitaxel for mobilization of peripheral blood progenitor cells.
(17/889)
We conducted a phase I trial to determine the dose and schedule of paclitaxel, when given together with filgrastim, which would optimally promote mobilization of stem cells with tolerable toxicity. Dose escalation began at 275 mg/m2 3 h infusion. Dose-limiting neuropathy was observed at the 300 mg/m2 dose level. A second dose escalation was conducted utilizing 24 h infusion schedules, beginning at 225 mg/m2. Dose escalation was continued by 25 mg/m2 increments to 300 mg/m2, at which dose neuropathy was again dose-limiting. The recommended dose and schedule of paclitaxel for the purpose of mobilization of stem cells, when given together with filgrastim, are 275 mg/m2 as a 24 h infusion. The median stem cell yield after this dose of paclitaxel was 6.6 x 10(6) CD34+ cells/kg/apheresis (range 3.6 x 10(6)-7.7 x 10(6)). (+info)
Cells with clonal light chains are present in peripheral blood at diagnosis and in apheretic stem cell harvests of primary amyloidosis.
(18/889)
In primary systemic amyloidosis, small numbers of bone marrow plasma cells secrete monoclonal light chains that form extracellular fibrils (amyloid) in various organs. Evidence limited to a few cases suggests that rare clonal elements can also be found in the peripheral blood (PB), and this may be relevant in PB stem cell autotransplantation. Since up to 40% of amyloid clones do not synthesize heavy chains, in order to detect tumor cells with high specificity and sensitivity we developed a seminested allele-specific oligonucleotide polymerase chain reaction for tumor light chains. Clone-related sequences were detected in DNA and/or cDNA from the PB cells of eight of 10 patients at diagnosis and from apheretic collections of three of four cases undergoing PB progenitor autotransplantation. Since there are experimental data suggesting that circulating tumor cells may be involved in the growth of the amyloidogenic clone and may be chemoresistant, these findings are relevant to the use of leukapheresis purging strategies for PB progenitor autotransplantation in amyloidosis. (+info)
Effective T cell regeneration following high-dose chemotherapy rescued with CD34+ cell enriched peripheral blood progenitor cells in children.
(19/889)
The ex vivo enrichment for the CD34+ cell fraction of PBPC, while it retains the capacity to restore haematopoiesis and potentially reduces a contamination by tumour cells, implements a depletion of T cells. To test whether such a setting adversely affects T cell reconstitution, we monitored T cells in four paediatric patients after CD34+ selected PBPC transplantation. The dose of CD34+ cells, which were enriched to 74%, median, was 7.1 x 10(6)/kg, median, that of T cells was 0.071 x 10(6)/kg, median. The patients were homogenous with respect to features with a potential to effect T cell reconstitution (low median age, (35 years); stage IV malignant tumours in first CR, uncomplicated post-treatment course). The results of sequential FACS analyses showed that by 9 months after treatment all four patients had recovered (1) a normal T cell count (CD3+ cells 1434/microl, median); (2) a normal CD4+ cell count (816/microl, median), while CD8+ cells were recovered (>330/microl) already by 3 months; (3) a normal CD4/CD8 ratio (1.8, median), as a result of an augmented growth of CD4+ cells between 3 and 6 months (increase of CD4+ cells 4.9-fold, median, CD8+ cells 1.1-fold, median). Expansion of cells with a CD45RA+ phenotype (thymus-derived T cells) predominated; from 3 to 6 months the increase of CD4+/CD45RA+ T cells was 130-fold, that of CD4+/CD45RO+ cells was 1.7-fold; CD8+/CD45RA+ cells increased 9-fold, CD8+/CD45RO+ cells increased 2.1-fold, indicating effective thymopoiesis. The findings demonstrate that in paediatric patients the setting of HD-CTX rescued with autologous CD34+ selected PBPC per se is not predictive of an impaired T cell recovery. High thymic activity may be a key factor for the rapid restoration of T cells. (+info)
Conclusions of a national multicenter intercomparative study of in vitro cultures of human hematopoietic progenitors.
(20/889)
With the aim of developing a standardized program of clonogenic cultures, a multicenter intercomparative study of human CFU-GM, BFU-E and CFU-GEMM cultures was conducted. Aliquots of fresh mononuclear cord blood cells, as well as uniform culture materials and instructions for cell culture and for colony scoring were distributed to 28 national laboratories involved in hematopoietic research and transplantation. High interlaboratory coefficients of variation (CV) in the reported number of progenitors were found in our first intercomparative study (range 67-231%). To investigate the relevance of colony scoring in variations of the reported colony numbers, participants were invited to attend a meeting where a single culture dish was scored. In this case, the CVs ranged from 31% to 81%. A subsequent intercomparative assay was then conducted, and significant reductions in the inter-laboratory CVs were obtained with respect to the first study (CVs for colonies grown with two different media: CFU-GMs, 48% and 55%; BFU-Es, 70% and 62%; CFU-GEMMs, 70% and 51%; respectively). In most instances CVs were not significantly different from those obtained in the single plate scoring study, suggesting that the scoring process was the most relevant parameter accounting for variations in the reported colony numbers. (+info)
Stem cell component therapy: supplementation of unmanipulated marrow with CD34 enriched peripheral blood stem cells.
(21/889)
Eleven patients with hematologic malignancies and two with aplastic anemia were treated using unmanipulated marrow and immunoselected CD34+ blood cells. Donors began G-CSF (10 microg/kg) injections 1 day after undergoing bone marrow harvest. Blood stem cells were collected on day 5 of G-CSF. Peripheral blood lymphocytes were depleted via CD34-positive selection. If, after marrow and blood harvest, less than 2.0 x 10(6) CD34 cells/kg were mobilized, leukapheresis was repeated on day 6. Median time to an absolute neutrophil count greater than 500 microl was day 10; transfusion-independent platelet count greater than 20,000/microl was day 13; average hospital discharge was day 14; and average inpatient hospital charges were 101,870 US dollars. Acute GVHD grade II occurred in five of 13 patients. No patient developed grade III or IV acute GVHD. At a median follow-up of 10 months, no patient has developed extensive chronic GVHD. Allografts of unmanipulated bone marrow supplemented with G-CSF-mobilized and CD34 immunoselected blood cells may prevent an increased risk of GVHD while preserving the rapid engraftment kinetics of peripheral blood. Supplementation of marrow with CD34 enriched blood cells appears to result in rapid engraftment, early hospital discharge, lower inpatient charges, decreased regimen-related toxicity, and no apparent increase in GVHD. (+info)
CD34+ cell enumeration in peripheral blood and apheresis samples, using two laboratory diagnostic kits or an institutional protocol.
(22/889)
In order to prepare the substitution of a commercially available diagnostic kit, ProCOUNT (Becton Dickinson) or Stem-Kit (Coulter Immunotech), for our institutional protocol, we compared the three techniques for the numeration of CD34+ progenitor cells in 50 peripheral blood and 51 apheresis samples, obtained from cancer patients or healthy donors. We show here that the three techniques yield results of the same order of magnitude. Although statistical analyses demonstrate significant differences between the three methods, these differences turned out to be clinically insignificant in most situations. Observed differences mostly affect samples with the highest content of CD34+ cells, while the three assays provide equivalent results for values that are close to clinically relevant thresholds (20 x 10(3) CD34+ cells/ml in peripheral blood to start apheresis, and accumulated number above 3 x 10(6) CD34+ cells/kg to stop apheresis). This study also supports the view that institutional protocols can provide a highly reliable determination of CD34+ cells counts and percentages. However, because institutional protocols often use research reagents and vary from institution to institution, the use of diagnostic kits may be prefered as one way to improve quality assurance in the practice of cell therapy. (+info)
Effects of long-term cryopreservation on hematopoietic progenitor cells in umbilical cord blood.
(23/889)
There is considerable interest in developing banks of frozen umbilical cord blood cells for transplants but it is uncertain how long frozen cells survive. Our objective was to determine the recovery of frozen umbilical cord blood cells. We quantitated recovery of hematopoietic progenitor cells (CFU-GM, BFU-E, and CFU-GEMM) from frozen umbilical cord blood cells stored for up to 12 years. Decay rates of CFU-GM, BFU-E and CFU-GEMM (d, expressed as percent of viable cells recovered (95% confidence interval) were 0.9930 (0.9889-0.9970), 0.9840 (0.9769-0.9911) and 0.9817 (0.9707-0.9927). Time-dependent recoveries, calculated by the formula d(k), (k = frozen storage interval in years) were >90% at 10 years. We conclude that frozen cord blood cells can be stored safely for prolonged intervals without substantial loss in hematopoietic progenitor cells. (+info)
Peripheral blood progenitor cell collections in cancer patients: analysis of factors affecting the yields.
(24/889)
BACKGROUND AND OBJECTIVE: Peripheral blood progenitor cells (PBPC) are now widely used to restore hematopoiesis following high dose chemotherapy in patients with malignancies. We sought to identify parameters that could predict the yield of PBPC after mobilization with chemotherapy (CT) with or without granulocyte colony-stimulating factor (G-CSF) in cancer patients. DESIGN AND METHODS: One hundred and fifty patients underwent 627 PBPC collections during the recovery phase following CT with (n = 469) or without (n = 142) G-CSF. Hemogram, CFC-assays and CD34+ cell count were performed on peripheral blood and leukaphereses products. After log transformation of the data, differences between groups were assessed with the unpaired t-test or one-way analysis of variance. RESULTS: Seventeen and two patients required 2 and 3 mobilization cycles respectively to reach our target of 15x10(4) CFU-GM/kg. In patients with lymphoma but not in those with leukemia, the yields of both CFU-GM and CD34+ cells/kg were dramatically increased when G-CSF was added to CT for mobilization. In collections primed with CT and G-CSF, better yields were obtained in patients with breast cancer or small-cell lung carcinoma (SCLC) as opposed to other solid tumors and leukemia. Among potential predictive factors of CT- and G-CSF-primed harvests, we found that the CD34+ cell count in peripheral blood (PB) was strongly correlated with both the CFU-GM and CD34+ cell yields. Except in leukemia patients, more than 1x10(6) CD34+ cells/kg were harvested when the CD34+ cell count in blood was above 20x10(6)/L. Similarly, better results were obtained in collections performed when the percentage of myeloid progenitors in blood on the day of apheresis was above 5 % or when the leukocyte count in blood was above 5x10(9)/L. INTERPRETATION AND CONCLUSIONS: A diagnosis of breast cancer or SCLC, a leukocyte count in PB of more than 5x10(9)/L, more than 5% myeloid progenitors or more than 20x10(6) CD34+ cells/L in PB were associated with higher yields of PBPC in collections mobilized with CT+G-CSF. (+info)