SampLink: a new system for the collection of donor blood samples.

Increasing demands for screening tests on blood donors, which require a large number of undiluted samples, and the rising concern for the safety of the phlebotomists have led to the development of a new blood sampling system. The new device was evaluated during the collection of 60 blood units, and compared with 50 control units collected using the "cut and drip' method. The time required for both blood donation and donor samples collection, blood component quality, coagulation factors activation and haemolysis were studied. In addition, reports and recommendations of Magen David Adom phlebotomists were evaluated after collecting 75000 units using the new device. Donor sample collection with the new device was comparable and somewhat shorter than with the "cut and drip' method, while the blood unit collection time remained unchanged. There were no differences in plasma haemoglobin, factor VIII and platelet yields and morphology scores in blood units and donor samples collected by the two methods. There were no reported instances of needle-sticks among phlebotomists using either method. The new device was simple to operate, improved blood donor samples collection practice and enabled the collection of as many undiluted donor samples as required for routine testing. In addition, the use of vacuum tubes ensured sterility, safety and standardization of samples. The components provided were comparable in quality to those prepared from units collected by other methods.

Restoration of murine cytomegalovirus (MCMV) induced myelosuppression by AS101.

Infection with cytomegalovirus (CMV) continues to be one of the most common complications following allogeneic bone marrow transplantation. The gravest danger for the host occurs when the virus is reactivated as a result of immunosuppression. In this report we studied the effects of sublethal murine cytomegalovirus (MCMV) infection on the hemopoietic system including bone marrow (BM) cellularity, production of colony stimulating factor (CSF) and interleukin-6 (IL-6) and the development of granulocyte-macrophage colony forming units (CFU-GM), and BM stromal cell viability. Our findings show that the virus infection led to a significant decrease in the number of BM cells and in the production levels of CSF and IL-6. There was also a decrease in the number of stromal cells, as reflected by the number of colony forming unit fibroblasts (CFU-F), and in the relative number of CFU-GM progenitors. Treatment of MCMV infected mice with the immunomodulator AS101 [ammonium trichloro (dioxyethylene 0-0')tellurate] restored significantly CSF and IL-6 production by BM cells to levels of uninfected control mice as well as the number of CFU-F and stromal cell elements which consequently led to the restoration of the total number of BM cells. Results presented here indicate that AS101 may have immunomodulatory effects on MCMV mediated myelosuppression. Administration of AS101 to patients with CMV associated BM damage may improve the restoration of their BM function.

Generation of T cell lines with suppressive activity derived from autorosette-forming cells of patients with autoimmune diseases.

A unique subpopulation of human suppressor autorosette-forming T cells was fractionated from peripheral blood of healthy donors and patients with various immune disorders. These cells have been maintained in long-term cultures and evinced suppressor activity in their supernatants. The study indicates the existence of a competitive relationship between the suppressor factors secreted by the cell lines and IL-2. It was found that impaired suppressor function can be related to a decrease in suppressors cell number, impaired function of individual suppressor cells, or failure to respond to active suppressor factors.

Cytokine secretion effected by synergism of the immunomodulator AS101 and the protein kinase C inducer bryostatin.

AS101, a synthetic organotellurium compound, was found to have immunomodulating properties by initiation of cytokine production in vitro and in vivo. Phase I/II clinical trials currently in progress on AIDS and cancer patients treated with AS101 show significant increases in various immunological parameters, with minimal toxicity. Recently, AS101 and the protein kinase C (PKC) inducer, phorbol myristate acetate (PMA), were shown to synergize in the secretion of interleukin-2 (IL-2) and colony-stimulating factor (CSF) in vitro, by human and mouse lymphoid cells. The bryostatins, a group of natural macrocyclic lactones isolated from marine invertebrates (Bugula neritina) have been reported to be potent PKC activators with no tumour promoting activity. In this study, we investigated the synergistic effect of AS101 and a partially purified preparation of bryostatin on the production of several cytokines. Our data confirm the presence of synergism, which greatly enhances cell proliferation, IL-2, tumour necrosis factor (TNF) and interferon-gamma (IFN-gamma) secretion by human mononuclear cells (MNC) and the production of IL-2 and TNF by mouse cells. The absence of tumour-promoting activity of the bryostatins makes them particularly good candidates, in combination with AS101, for immunomodulation in vivo in clinically immunosuppressed conditions.

Cell lines derived from human autorosette-forming cells with suppressive activity.

Concanavalin-A-stimulated human T lymphocytes from healthy donors and from patients suffering from diverse immune disorders were fractionated into rosette-forming (R) and nonrosette-forming (NR) cells. The separation method is based upon the ability of the lymphocytes to bind autologous erythrocytes and form autorosettes. Long-term cultures of the R and NR subpopulations were established. The activity of the culture supernatants on the T cell proliferation of normal human phytohemagglutinin (PHA)-induced lymphocytes and of a murine, interleukin-2 (IL-2)-dependent cytotoxic T cell line (CTLL) was investigated. Only the R cell line-derived supernatants from almost all patients tested evinced potent suppressor activity, those from healthy donors less so. The suppressive function was demonstrated not to be due to a cytotoxic effect since preincubation of the PHA-induced lymphocytes and CTLL cells with the factor did not diminish their proliferative capacity. Our study indicates the existence of a competitive relationship between the suppressor factor and IL-2. We found that inhibition of the proliferation decreased with the addition of increasing quantities of exogenous IL-2. We also observed that preincubating the CTLL cells with IL-2 prior to exposing them to the suppressive factor precludes inhibition of their proliferation. Phenotypic analysis of the suppressor cell line revealed that they were comprised of a T cell population which included OKT4+ and OKT8+ cells and that 99% of the cells formed autorosettes. Preliminary purification of the suppressive factor was performed by ultrafiltration and maximal suppression was exhibited by the fraction of less than 10,000 daltons. The development of suppressor cell lines from the unique population of autologous rosette-forming cells may be very helpful in studying the immunoregulatory properties of these cells and their suppressor activity.

Immunologic effects of AS101 in the treatment of cancer patients.

AS101 [ammonium trichloro(O,O'-dioxyethylene)tellurate] is a new immunomodulator previously shown to stimulate the production of different cytokines in vitro and in vivo. We report here our results of a phase I clinical trial conducted on 47 cancer patients with advanced malignancies. AS101 was administered intravenously at escalating doses from 1 to 10 mg/m2, twice or thrice a week. The maximal tolerated dose has not yet been determined. However, significant immunologic responses were noted at dose levels of 1-3 mg/m2 administered three times a week. At these doses statistically significant rises in gamma-interferon, natural killer cell activity, tumor necrosis factor and interleukin-2 (IL-2) levels as well as the expression of IL-2 receptors were noted. In most of the immunologic parameters the maximal response was seen at 3 mg/m2. Throughout the study toxicity was minimal. In view of these results phase II studies are currently being initiated.

An evaluation of the SCM test for the diagnosis of cancer of the breast.

The SCM test (structuredness of the cytoplasmic matrix) consists of measuring the fluorescence polarization of fluorescein which is introduced into a particular sub-group of peripheral lymphocytes. The test has a non-specific part for the general detection of cancer and a specificity procedure which is based on the use of specific cancer extracts. In this article we deal only with the latter in relation to breast cancer. Blood samples from 94 patients have been tested; six of these had mastectomy performed previously; 83 underwent consecutively a surgical procedure and histology was obtained; five were only clinically examined. In 45/49 (92%) patients, correlation between a positive specificity test and tissue malignancy was found. Out of 35 patients with non-malignant proliferative lesions (as found by histology), 25 reacted positively in the test. Two out of five patients with non-malignant, non-proliferative lesions reacted positively in the test. Five patients who were defined as normals by clinical examination reacted negatively in the test. These results indicate the potential of the SCM test for detecting breast malignancy. The clinical implications of the test for cancer diagnosis are discussed.

Colony growth in vitro of mitogen-stimulated mouse B lymphocytes.

The ability of mouse B-mitogen-induced lymphocytes to grow and develop into colonies in a soft agar system was studied. Prerequisite conditions for the colony formation of mouse lymphocytes from inguinal lymph nodes of strains ICR C3H/eB and C3H were their suspension in a liquid medium and stimulation with polyclonal B-cell activators such as bacterial lipopolysaccharide (LPS), purified protein derivative (PPD) or dextran sulphate (DxS) prior to being seeded on a soft agar culture medium. After 3-5 days of culture, colonies of 50-350 cells or more per clone developed. A linear relationship was found between the number of cells seeded and the number of colonies growing. Of the cells seeded, only a limited population of the mitogen-stimulated lymphocytes has the potential to divide and to develop into colonies. The largest number of colonies was obtained by culturing lymph node cells of ICR mice and using LPS as mitogens. Two sublines of C3H were found to respond differently to LPS: C3H/HeJ mice were low responders while C3H/eB mice were high responders. Experiments with inbred, congenitally athymic nude (nu/nu) mice known to be deficient in T cells showed that LPS-stimulated lymphocytes were capable of forming colonies. The morphology of the colony cells, as well as the fact that they stain positively for cell-membrane immunoglobulins, suggest that the colonies developed from B lymphocytes.