In vitro collection and posttransfusion engraftment characteristics of MNCs obtained by using a new separator for autologous PBPC transplantation.

BACKGROUND: A clinical study was performed to evaluate the peripheral blood progenitor cell (PBPC) collection, transfusion, and engraftment characteristics associated with use of a blood cell separator (Amicus, Baxter Healthcare). STUDY DESIGN AND METHODS: Oncology patients (n = 31) scheduled for an autologous PBPC transplant following myeloablative therapy were studied. PBPCs were mobilized by a variety of chemotherapeutic regimens and the use of G-CSF. As no prior studies evaluated whether PBPCs collected on the Amicus separator would be viable after transfusion, to ensure patient safety, PBPCs were first collected on another cell separator (CS-3000 Plus, Baxter) and stored as backup. The day after the CS-3000 Plus collections were completed, PBPC collections intended for transfusion were performed using the Amicus instrument. For each transplant, >2.5 x 10(6) CD34+ PBPCs per kg of body weight were transfused. RESULTS: Clinical data collected on the donors immediately before and after PBPC collection with the Amicus device were comparable to donor data similarly obtained for the CS-3000 Plus collections. While the number of CD34+ cells and the RBC volume in the collected products were equivalent for the two devices, the platelet content of the Amicus collections was significantly lower than that of the CS-3000 Plus collections (4.35 x 10(10) platelets/bag vs. 6.61 x 10(10) platelets/bag, p<0.05). Collection efficiencies for CD34+ cells were 64 +/- 23 percent for the Amicus device and 43 +/- 14 percent for the CS-3000 Plus device (p<0.05). The mean time to engraftment for cells collected via the Amicus device was 8.7 +/- 0.7 days for >500 PMNs per microL and 9.7 +/- 1.5 days to attain a platelet count of >20,000 per microL-equivalent to data in the literature. No CS-3000 Plus backup cells were transfused and no serious adverse events attributable to the Amicus device were encountered. CONCLUSIONS: The mean Amicus CD34+ cell collection efficiency was better (p<0.05) than that of the CS-3000 Plus collection. Short-term engraftment was durable. The PBPCs collected with the Amicus separator are safe and effective for use for autologous transplant patients requiring PBPC rescue from high-dose myeloablative chemotherapy.

Biocompatibility test procedures for materials evaluation in vitro. II. Objective methods of toxicity assessment.

Methods of assessing the biocompatibility of materials for use in medical devices were evaluated. Ten materials were tested using quantitative, objectively graded in vitro biochemical and functional assays employing four cell lines (CCL 1, 74, 76, and 131) used in previous work and five primary cell types (human lymphocytes, polymorphonuclear leukocytes, and mixed leukocytes, mouse macrophages, and mouse embryo). The biochemical methods (DNA synthesis, protein synthesis, and ATP activity) demonstrated good agreement in toxicity ranking of the materials, regardless of which cell culture was used and, also, the cell cultures responded similarly for each method. Methods that measured functional characteristics of cells (adhesion and phagocytosis) were highly sensitive but had low toxicity ranking agreement and reproducibility. Assays (defined as method and cell culture combinations) using cell lines were more reproducible than assays using primary cell types. Significant differences in sensitivity were noted among the assay systems for particular material types. The in vitro assays were more sensitive to differences in material composition than was a 90-day assay by subcutaneous implantation in rats.

Biocompatibility test procedures for materials evaluation in vitro. I. Comparative test system sensitivity.

Relative sensitivity of in vitro biocompatibility test systems was explored. Cellular responses of 12 standardized cell lines to 20 materials representing a range of toxicity were measured. Each cell line and material combination was tested in duplicate using four different culture methods, and each culture plate was examined by two graders. Results of the tissue culture assays were compared to those obtained for the same materials in vivo using a 5-day rabbit intramuscular implant assay. Methods involving measurement of cellular growth (colony counts or percent of confluence) in serum-fortified media extracts of test samples were generally more sensitive and discriminating than those in which test materials were placed directly in cell cultures (measurement of zone of growth inhibition). There was good agreement between graders for all test methods. Antibiotics were not used in the test program. Based upon sensitivity, reproducibility, ability to discriminate materials, and grader agreement, 4 of the 12 cell lines and 2 of the 4 test methods appeared most suitable for screening and evaluation of materials. Agreement of results using these four cell lines with intramuscular implantation tests for the 30 materials ranged from 60 to 90%.