Reduction of human immunodeficiency virus-infected cells from donor blood by leukocyte filtration

Several filters for leukocyte removal were evaluated in terms of their ability to reduce the cell-associated human immunodeficiency virus (HIV) load in units of blood either inoculated in vitro with lymphocytes from a chronically infected cell line or collected directly from seropositive donors. Filtration of the experimentally inoculated units of blood resulted in a 5.9 log 10 mean reduction (95% confidence interval:7.4-4.5) of tissue culture infectious units (TCIU) as assayed by end-point titration using the coculture assay. Filtration of the units of blood from anti-HIV positive donors lowered the infectivity by over 2 logs, as detected by the coculture and polymerase chain reaction (PCR) techniques. However, residual cell-associated virus was detected in the majority of experiments. Clinical studies are warranted to determine if leukocyte filtration of blood will reduce the risk of transfusion transmitted viral infections.     

Prestorage leukocyte reduction of cellular blood components

With the increasing demand for leukoreduced cellular blood components, many blood centers in Europe, North America, and Asia have begun to prepare leukocyte depleted cellular blood components prior to storage. Increased understanding of transfusion complications resulting from recipient exposure to residual donor leukocytes has focused attention on donor leukocytes during blood storage. This review examines production options for prestorage leukocyte removal, considers approaches to quality control, discusses proposed laboratory and clinical advantages of leukoreduction prior to storage compared with after storage, and suggests a strategy for cost-effective implementation of widespread prestorage leukocyte removal.     

Reduction of blood coagulation and monocyte-platelet interaction following the use of a minimal extracorporeal circulation system (Synergy) in coronary artery bypass grafting (CABG)

Cardiovascular surgery with cardiopulmonary bypass (CPB) induces activation of blood coagulation and systemic inflammation involved in post-operative complications. Our study evaluated the impact of the minimal extracorporeal circulation (mini-CPB) system (Synergy, Sorin Group) on these functional aspects. Twenty patients were randomly assigned to standard CPB (n = 10) or to Synergy (n = 10). Platelet expression of PAC-1, and monocyte/granulocyte-platelet conjugates were evaluated by flow cytometry. A leukocyte-platelet adhesion index was calculated after cell number normalization. ELISAs were performed to measure IL-6 and TNF-alpha, thrombin-antithrombin III complexes (TAT), prothrombin fragments (F1+2), beta-thromboglobulin (beta-TG) and sP-selectin (sCD62P). Blood samples were drawn at the time of anesthesia (T1), at the end of CPB (T2), and at 4 (T3) and 24 hours (T4) after weaning from CPB. All patients were similar for clinical characteristics. When compared to standard CPB, the Synergy showed lower levels of the monocyte-platelet adhesion index at T2 (0.023 +/- 0.005 vs 0.063 +/- 0.013, P = 0.0092) and T4 (0.031 +/- 0.003 vs 0.055 +/- 0.005, P = 0.0017), TAT complexes at T2 (27.175 +/- 5.967 vs 86.592 +/- 5.415, P = 0.0005) and T3 (26.977 +/- 2.468 vs 45.146 +/- 4.365, P = 0.0041), F1+2 fragments at T2 (2.222 +/- 0.226 vs 4.249 +/- 0.292, P = 0.0009), and sP-selectin at T3 (115.17 +/- 19.623 vs 169.554 +/- 19.709, P = 0.0703) and T4 (108.542 +/- 6.429 vs 140.799 +/- 14.771, P = 0.0833). In summary, the Synergy exhibited a lower post-operative activation of blood coagulation, together with a reduced interaction between circulating monocytes and platelets.     

血细胞自动化分析后血涂片复审标准制定的原则与步骤

根据血细胞分析方法的变迁和仪器法血细胞检测后血涂片复审的现状,结合血涂片复审41条国际规则,介绍临床实验室制定血涂片复审标准的原则和步骤,以及值得注意的问题.     

Efficacy of leukocyte depletion of residual pump blood

In this study, we examined whether leukocyte depletion from the residual heart-lung machine blood at the end of cardiopulmonary bypass (CPB) has an effect on the leukocyte counts in the systemic circulation. Twenty-six patients undergoing coronary artery bypass grafting (CABG) were randomly allocated to a leukocyte-depletion group or a control group. In the leukocyte-depletion group (n = 13), all residual blood (400 mL to 1.4 L) was filtered by leukocyte-removal filters (Pall RS01) and reinfused to the patient after CPB, whereas, in the control group, an identical amount of residual blood after bypass was reinfused without filtration (n = 13). Leukocyte-depleted allogeneic blood was transfused if needed. Preoperative risk profiles, pump support and duration of aortic crossclamping time were identical in both patient groups (ns). Leukocyte depletion removed more than 96% of leukocytes from the residual retransfused blood (p < 0.01) and significantly reduced circulating leukocytes (p < 0.05) compared with the control group. Remarkably, lower numbers of circulating leukocytes were found, not at 1 hour after reinfusion, but at 4 and 8 hours after reinfusion (p < 0.05). There were no statistical differences between the two groups with respect to postoperative blood loss, the number of transfused packed red cells and mechanical ventilation time. These results show that leukocytes can be removed from the residual blood of the heart-lung machine after CPB very effectively. Furthermore, this leukocyte depletion results in a long-term effect, the clinical significance of which has to be elucidated in ongoing studies.     

Optimal leukocyte removal from refrigerated blood with the IBM 2991 blood cell processor

One hundred forty-six units of two to five-day-old refrigerated blood were washed with the IBM Blood Cell Processor. The ABO and Rh types of the units varied according to available inventory. This study was designed to select the best protocol from the 42 possible combinations utilizing the machine's variable red blood cell override (RCO). A one liter wash program was used. The two parameters selected for study were the per cent red blood cell recovery and the per cent white blood cell removal. The protocol of choice uses a RCO of four seconds in the first and second steps of the program. This protocol yields a washed unit with a mean red blood cell recovery of 82 per cent and a mean white cell removal of 93 per cent. Our studies indicate that the IBM Blood Cell Processor can be used to wash two to five day old refrigerated blood for the preparation of leukocyte-poor blood that would meet the Standards of the AABB.     

Reduction of calcitonin gene-related peptide in jugular blood following electrical stimulation of rat greater occipital nerve

Although it is known that pain in the forehead may be induced by neck abnormalities, the actual neck-head connections responsible for development of pain in trigeminal areas are poorly understood. Vasoactive neuropeptides released from sensory fibres, such as substance P (SP) and calcitonin gene-related peptide (CGRP), have been considered as important elements in headache pathophysiology. The levels of CGRP-like immunoreactivity (LI) were measured bilaterally in the jugular blood (52 rats) and intraocular aspirates (66 rats) following electrical stimulation of the left greater occipital nerve, and in the jugular blood of 13 control animals. One-third of the stimulated rats had varying combinations of conjunctival injection, tearing, diminished eye aperture and miosis or mydriasis on the stimulated side. The other two-thirds exhibited no ocular signs. Significantly lower levels of CGRP-LI were present in the jugular blood on the stimulated side in comparison with control rats. There was comparatively lower CGRP-LI on the non-stimulated side as well, but to a lesser extent. Significant differences between the stimulated and the non-stimulated side were present, particularly in the tearing/diminished eye cleft group. It is proposed that stimulation of the rat GON inhibits the trigeminal system (reduction of CGRP-LI) and possibly activates parasympathetic fibres (ocular changes).     

Accurate quantitation of the low number of white cells in white cell- depleted blood components

A simple method of accurate quantification of low concentrations of white cells (WBCs) in WBC-depleted blood components was developed by using propidium iodide (PI) to stain the nuclei of WBCs. The method was validated by correlating the PI-determined WBC concentrations with those determined with Coulter S-plus IV counter in units of packed red cells (PRBCs) or random-donor platelets (RDPs). The correlations were linear and had coefficients of 0.99. The sensitivity of PI staining permitted the detection of concentrations of WBCs as low as 1 cell per microL of RDPs or 11 cells per microL of PRBCs. Therefore, PI staining will be useful in investigating the role of transfused WBC-depleted blood components in the prevention of primary alloimmunization to HLA antigens, as well in evaluating various new procedures with high efficiency in depleting WBCs from blood components.     

Acupuncture regulates leukocyte subpopulations in human peripheral blood

Acupuncture has recently been attracting more and more peoplethroughout the world as an alternative treatment, however littleis known about its physiological activities (i.e. immune system).We examined acupuncture both quantitatively and qualitativelyby measuring CD-positive cell counts and cytokine expressionlevels in the blood, to determine the activity of T cells, Bcells, macrophages and natural killer (NK) cells. Fifteen millilitersof peripheral blood obtained from 17 healthy volunteers aged21–51 years, were analyzed using flow cytometry beforeand after acupuncture treatment. There was a statistically significantincrease in the number of CD2⁺, CD4⁺, CD8⁺, CD11b⁺, CD16⁺, CD19⁺,CD56⁺ cells as well as IL-4, IL-1β and IFN- levels in thecells after acupuncture stimulation of meridian points. Theseobservations indicate that acupuncture may regulate the immunesystem and promote the activities of humoral and cellular immunityas well as NK cell activity. In this article, we discussed howacupuncture regulated leukocyte numbers and functions sincethey are considered to be potential indicators for evaluatingcomplementary and alternative medicine.     

Temperature dependence of leukocyte depletion of blood with an automatic blood cell processor

The proportion of leukocytes removed by a cell processor in the provision of leukocyte-depleted blood was found to be dependent on temperature. If both blood and washing saline were at room temperature, more leukocytes were removed than if either the blood or the saline or both were at 4 degrees C. Room temperature processing provides an optimal product for the recipient who requires leukocyte-depleted blood.