Mobilized peripheral blood is increasingly used as the source of hematopoietic stem cells for allogeneic transplantation, currently the only curative approach for sickle cell anemia. However, the safety and feasibility of stem cell mobilization in individuals with sickle cell trait (SCT) has not been documented. This study is a prospective controlled trial to evaluate the safety and feasibility of peripheral blood stem cell (PBSC) mobilization in 8 SCT subjects and 8 control subjects matched for age and race. Mobilization with filgrastim 10 g/kg subcutaneous daily for 5 days was followed by 12-L apheresis on the fifth day. Filgrastim administration was accompanied by similar symptoms in all subjects; no untoward adverse events occurred in either group, including sickle cell crises. CD34 ؉ cell mobilization response was not significantly different between SCT and control subjects. Median CD34 ؉ cell content was also similar in PBSCs collected from SCT versus control subjects, 6.8 versus 3.9 ؋10 6 CD34 ؉ cells/70 kg, P ‫؍‬ .165. Red cell depletion from SCT products was not possible by using hydroxyethyl starch sedimentation but was achievable with ammonium chloride lysis. There was no evidence of gelling of SCT products after thaw, and no difference in cell recovery was seen among red cell-depleted versus nondepleted products. Cryopreservation in 5% dimethyl sulfoxide/6% pentastarch was associated with superior cell recovery (both SCT and control subjects) compared with 10% dimethyl sulfoxide (P ‫؍‬ .001). The study concluded that filgrastim mobilization, large volume apheresis, processing, and cryopreservation appears to be safe in donors with SCT, allowing PBSC use for transplantation in patients with sickle cell anemia. (Blood. 2002;99:850-855)

Summary:We previously demonstrated findings suggestive of autologous GVHD in patients receiving IL-2-activated peripheral blood stem cells (PBSC) with IL-2 after transplantation. A pilot study was designed to test tolerability, feasibility and frequency of autologous GVHD and engraftment using IL-2 and ␣-IFN posttransplantation. After cyclophosphamide (6 g/m 2 ) and carboplatin (1800 mg/m 2 ), patients with high-risk stage II or III breast cancer received chemotherapy and rhG-CSF mobilized autologous PBSC that had been cultured in IL-2 for 24 h. Subcutaneous administration of IL-2 began on day 0 at 6 × 10 5 IU/m 2 /day for 5 of 7 days each week and continued for 4 weeks. Once engraftment occurred, ␣-IFN was initiated at a dose of 1 × 10 6 /m 2 /day subcutaneously for 30 days. Thirty-four consecutive patients with stage II (n = 20), IIIA (n = 6) and IIIB (n = 8) disease were treated. All patients were without evidence of disease at the time of transplantation. The average time required for the ANC to reach 500/mm 3 was 10 days (range: 8-11 days) and for platelets to reach 20 000/mm 3 was 10.7 days (range: 6-21 days). Forty-seven percent of patients (n = 16) completed the full course of immunotherapy; the remaining patients received attenuated doses due to patient's request (n = 6), development of temperature Ͼ38؇C (n = 3), development of neutropenia (n = 3), serious infection (n = 1) and miscellaneous reasons (n = 5). Four patients experienced transient moderate toxicities (level 3) including elevated liver function tests, nausea, rash and capillary leak syndrome. Pathological findings suggestive of skin GVHD developed in 43% of patients (12/28 patients) when skin biopsies were evaluated in a blinded fashion. At 13 months post-transplant (median; range: 5-24 months), 28 patients (82%) remain diseasefree. These results demonstrate the feasibility and toxicity of this regimen along with pathological findings compatible with autologous GVHD of the skin. Keywords: interleukin-2; ␣-interferon; breast cancer; stem cell transplantation; immunotherapy Hematopoietic stem cell (HSC) transplantation may improve disease-free survival for selected women with stage II-IV breast cancer. 1-3 Any attempt to further improve therapeutic efficacy by increasing chemotherapy dose may result in excessive nonhematologic toxicities. Immunomodulation, in conjunction with high-dose chemotherapy and HSC transplantation may offer a potential benefit by providing a non-cross-resistant mechanism of tumor cell kill with non-overlapping toxicities. In addition, immunotherapy following autologous HSC transplantation has been associated with the development of graft-versushost disease (GVHD). [4][5][6] The generation of autologous GVHD in patients undergoing autologous HSC transplantation using immunomodulation, has been described in patients with breast cancer, multiple myeloma, lymphoma and acute myelogenous leukemia. [7][8][9][10][11][12] In the allogeneic BMT setting, the existence of GVHD is presumed to be associated with a graft-versus-tumor...

We surveyed five academic medical centers to develop a clinical process for patients undergoing cytokine mobilization and leukapheresis prior to autologous peripheral blood stem cell transplantation. Costs were obtained from three centers and applied to each component of the pathway. Costs were divided into three categories: (1) pre-apheresis evaluation; (2) process of apheresis; (3) post-apheresis and peripheral blood stem cells processing. All centers participated in the development of the leukapheresis pathway. Because charges vary greatly among institutions, costs were determined from three of the institutions and a mean was calculated for each of the components of the process. Pre-apheresis costs consisted of central line placement, blood work, and the price of cytokine (rhG-CSF). Costs associated with apheresis included professional fees (for physicians and nurses), leukapheresis with stem cell cryopreservation, storage, sterility testing, analysis of circulating CD34+ cell counts, and 1 day of cytokine therapy. The post-apheresis process included thawing with sterility testing along with CD34+ cell number analysis and the performance of clonogenic assays. Total costs were as follows: (1) pre-apheresis, $2711; (2) apheresis, $2990; and, (3) post-apheresis/stem cell processing, $754. This survey from five academic medical centers provides the average costs associated with three main components of the apheresis procedure. Because many patients require multiple aphereses, interventions to achieve target CD34+ cell collections in as few collections as possible would result in significant cost reduction.

A concentrate of mononuclear bone marrow cells is often desired for ex vivo treatment with pharmacologic agents, monoclonal antibodies, cytokines, and other agents prior to transplantation. A method has been developed for automated separation of mononuclear cells from large volumes of harvested bone marrow. A programmable instrument originally designed for clinical ex vivo cell separation and the plasma-pheresis of patients and blood donors was adapted to permit rapid preparation, in a closed sterile system, of a bone marrow product enriched with mononuclear cells. A mean (+/- SEM) of 53 +/- 30 percent of the original mononuclear cells was recovered in a volume of 125 +/- 42 mL containing 82 +/- 12 percent mononuclear cells. This technique removed 95 +/- 9 percent of the red cells in the original marrow. No density gradient materials or sedimenting agents were employed in this process. Of 36 marrows processed by this technique, 19 autologous (6 of which were purged with 4-hydroperoxycyclophosphamide) and 7 allogeneic marrows have been transplanted, with all evaluable patients achieving a neutrophil count of 0.5 x 10(9) per L in a mean (+/- SEM) of 21 +/- 6 days.