The effect of storage on the metastatic potential of tumor cells collected in autologous blood. An animal model

Malignancy in a potential autologous blood donor is considered by some as a relative contraindication for the collection of autologous blood. There is, however little experimental information regarding the safety of transfusion of autologous blood that may contain viable tumor cells. The purpose of this study was to determine if tumor cells seeded into autologous blood retain their metastatic potential and, if so, for how long. A well-established model of the pulmonary metastasis of B16/F10 (F10) melanoma in C57BL/6 mice was used. Equal numbers of F10 cells were seeded into CPDA-1 blood from the mice or into saline, and the number of lung tumors was evaluated 14 days after infusion of blood or saline. The CPDA-1 blood seeded with F10 cells was stored for up to 21 days in transfer packs at 4 to 6 degrees C, and the metastatic potential of F10 cells in the stored blood was ascertained as above. F10 cells seeded into autologous blood that was then transfused without storage gave rise to the same number of metastatic foci (404 +/- 32 metastases) as did those cells transfused in saline (374 +/- 38, p = 0.5). In contrast, the number of metastatic foci resulting from the transfusion of blood containing F10 cells decreased progressively after storage of the blood (7 days = 124 +/- 14 metastases; 14 days = 7 +/- 1; 21 days = 2 +/- 1; all p values less than 0.001 vs fresh blood). Also, the predilection of F10 cells to metastasize to the lung was unchanged by storage in blood.(ABSTRACT TRUNCATED AT 250 WORDS)     

REPRODUCIBILITY OF CONVENTIONAL AND POWER SPECTRAL MEASUREMENTS OF CARDIOVASCULAR SYMPATHETIC ACTIVATION IN NORMAL SUBJECTS

1. Normal subjects (n = 5; age 20-42 years; mean resting blood pressure (± 1 s.d.) 116±21/61±11 mmHg) underwent cardiovascular reflex testing five times each. On every occasion systolic blood pressure (SBP) responses to sustained handgrip (GRIP) and cold pressure (COLD) tests were measured and continuous non-invasive SBP and heart period (RRINT) data were analysed in the frequency domain using fast Fourier transforms. Power spectral (PS) density estimates of high frequency/total power (HF%; a measure of vagal activity), low frequency/HF ratio (LF/HF; a measure mainly of cardiovascular sympathetic activity for heart period) and low frequency/total power (LF%; a proposed measure of sympathetic activity for SBP) at rest, during and 2min after the end of stimuli were calculated. 2. The data from the rest and recovery periods did not differ and showed that cardiovascular recovery to baseline measures following sympathetic stimulation occurred within 2 min. 3. There was a significant rise in SBP with GRIP and COLD. The LF/HF(RRINT) rose significantly with GRIP, but not with COLD. The LF%(SBP) did not change significantly with GRIP or COLD. 4. The SBP and PS analyses showed low intra-individual reproducibility of responses to reflex tests, with coefficients of variation for PS measures at rest of 25-41% and on sympathetic stimulation of up to 80%. 5. The high variability of these observations indicates that PS methods may not be suitable for the analysis of transient cardiovascular reflexes.     

APO-1-induced apoptosis of leukemia cells from patients with adult T- cell leukemia

The 48-Kd cell-surface protein APO-1 is a new member of the nerve growth factor (NGF)/tumor necrosis factor (TNF) receptor superfamily. APO-1 is expressed on various cells, including activated T and B cells and some lymphoid and nonlymphoid cell lines. Triggering of APO-1 by the monoclonal antibody anti-APO-1 induces programmed cell death (apoptosis) in APO-1-expressing cells. APO-1 is also present on T-cell lines derived from patients with adult T-cell leukemia (ATL). Therefore, we investigated APO-1 expression and APO-1-mediated induction of apoptosis ex vivo in cells from patients with ATL. Fresh leukemic cells from nine patients with ATL were assayed for APO-1 expression by two-color immunofluorescence. The leukemic cells from all patients strongly expressed APO-1. Incubation of ATL cells with anti- APO-1 in vitro inhibited spontaneous and cytokine-mediated DNA synthesis. Furthermore, DNA isolated from cells treated with anti-APO-1 exhibited polynucleosomal DNA fragmentation (DNA ladder) characteristic for apoptotic cell death. The analysis of APO-1-mediated apoptosis may represent a new approach to the study of growth control in lymphoid malignancies. In addition, induction of apoptosis by administration of anti-APO-1 may represent a new therapeutic approach for aggressive T- cell malignancies such as ATL.     

Treatment of acute graft-versus-host disease with humanized anti-Tac: an antibody that binds to the interleukin-2 receptor

Humanized anti-Tac is a genetically engineered human IgG1 monoclonal antibody specific for Tac, the alpha subunit of the interleukin-2 (IL- 2) receptor, and blocks IL-2-dependent activation of human T lymphocytes. The safety, pharmacokinetics, and immunosuppressive activity of humanized anti-Tac were evaluated in 20 patients who developed acute graft-versus-host disease (GVHD) after allogeneic marrow transplantation. Patients had developed acute GVHD at 5 to 26 (median, 14) days after transplantation and had failed to respond to primary therapy with glucocorticoids. Sequential groups of 4 patients each received a single 1-hour infusion of antibody in escalating doses of 0.5, 1.0, or 1.5 mg/kg; 8 additional patients were then treated with 1.5 mg/kg. A second infusion of antibody was administered after 11 to 48 (median, 16) days in 8 patients who had transient improvement of GVHD after the first infusion. Acute side effects, limited to chills in 1 patient and diaphoresis in another, were observed during or shortly after the antibody infusion. Overall improvement of acute GVHD occurred in 8 patients, 6 of whom were treated with a single antibody infusion and 2 with two infusions. Four responses were complete and 4 were partial. Three additional patients had improvement in one organ but progression in another. Responses occurred in 9 of 16 cases with skin disease, 3 of 15 with liver disease, and 6 of 12 with gastrointestinal disease. Two patients survive at 529 and 645 days after antibody treatment. Two patients died after relapse of leukemia. Sixteen patients died of infection or organ failure between 5 and 211 (median, 55) days. The terminal elimination half-life of the antibody was 44 to 363 hours, with a harmonic mean of 79, 88, and 94 hours, respectively, for the three doses studied. Absolute peripheral blood T-lymphocyte counts remained unchanged during the 56 days after infusion of the antibody. A fraction of circulating T cells expressed the alpha chain of the IL-2 receptor that, in some patients, was bound by antibody in vivo up to 28 days after treatment. No patient developed a measurable antibody response to humanized anti-Tac. Humanized anti-Tac has a long half-life after intravenous injection in humans, superior to any rodent monoclonal antibody specific for human T cells, and does not appear to induce antibody formation in recipients of marrow transplants. Improvement of steroid-refractory GVHD in 40% of patients after only one or two antibody infusions indicates that humanized anti-Tac is immunosuppressive.