Crossmatch difficulties following the prophylactic use of Rh immune globulin. (1/44)

With increasing demand for platelet transfusion the need to use platelets from Rh-positive persons for Rh-negative individuals often arises. The administration of Rho(D) immune globulin (human) in this situation has been recommended, but may cause serologic difficulties owing to the recipient's passive acquisition of antibodies other than anti-D.  (+info)

The use of PEG-rhuMGDF in platelet apheresis. (2/44)

Platelet transfusions are increasingly being used to treat thrombocytopenic conditions ranging from aplastic anemia to that caused by cancer chemotherapy. Although historically whole-blood transfusions were the primary source of platelets for transfusion, random donor platelet concentrates and single-donor apheresis platelets are currently the only products used. The use of these products in the United States varies widely for different medical conditions; for example, surgical patients receive random donor platelet concentrates much more commonly than single-donor apheresis products, while the opposite is true for hematology/oncology patients. The past decade has seen a great change in the type of platelet product prescribed. Whereas random donor platelet concentrates were mostly used in the past, over 60% of the platelets transfused are now obtained from donors by apheresis. A crucial variable in the ability to collect platelets by apheresis is the donor platelet count. With the recent availability of thrombopoietin, there has been considerable interest in using this hematopoietic growth factor to stimulate platelet production in donors. Preliminary studies with the administration to platelet donors of one of the thrombopoietic growth factors, PEG-rHuMGDF, have demonstrated a marked increase in the apheresis yield and no side effects. The PEG-rHuMGDF-mobilized platelets were effective upon transfusion. Whether stimulation of platelet production in donors with thrombopoietic growth factors will become a widely accepted method will depend largely on the safety of this approach for the donor as well as on a number of lesser issues which concern the recipient and blood center.  (+info)

Thrombopoietin therapy increases platelet yields in healthy platelet donors. (3/44)

The recombinant thrombopoietins have been shown to be effective stimulators of platelet production in cancer patients. It was therefore of interest to determine if one of these, pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF), could be used to increase platelet counts and consequently platelet yields from apheresis in healthy platelet donors. In a blinded, 2-cycle, crossover study, 59 platelet donors were randomized to receive a single subcutaneous injection of PEG-rHuMGDF (1 microg/kg or 3 microg/kg) or placebo and 15 days later undergo platelet apheresis. Donors treated with placebo had a median peak platelet count after PEG-rHuMGDF injection of 248 x 10(9)/L compared with 366 x 10(9)/L in donors treated with 1 microg/kg PEG-rHuMGDF and 602 x 10(9)/L in donors treated with 3 microg/kg PEG-rHuMGDF. The median maximum percentage that platelet counts increased from baseline was 10% in donors who received placebo compared with 70% in donors who received 1 microg/kg and 167% in donors who received 3 microg/kg PEG-rHuMGDF. There was a direct relationship between the platelet yield and the preapheresis platelet count: Placebo-treated donors provided 3.8 x 10(11) (range 1.3 x 10(11)-7.9 x 10(11)) platelets compared with 5.6 x 10(11) (range 2.6 x 10(11)-12.5 x 10(11)) or 11.0 x 10(11) (range 7.1 x 10(11)-18.3 x 10(11)) in donors treated with 1 microg/kg or 3 microg/kg PEG-rHuMGDF, respectively. Substandard collections (<3 x 10(11) platelets) were obtained from 26%, 4%, and 0% of the placebo, 1 microg/kg, and 3 microg/kg donors, respectively. No serious adverse events were reported; nor were there events that met the criteria for dose-limiting toxicity. Thrombopoietin therapy can increase platelet counts in healthy donors to provide a median 3-fold more apheresis platelets compared with untreated donors.  (+info)

Prophylactic platelet transfusions from healthy apheresis platelet donors undergoing treatment with thrombopoietin. (4/44)

Many patients receiving dose-intensive chemotherapy acquire thrombocytopenia and need platelet transfusions. A study was conducted to determine whether platelets harvested from healthy donors treated with thrombopoietin could provide larger increases in platelet counts and thereby delay time to next platelet transfusion compared to routinely available platelets given to thrombocytopenic patients. Community platelet donors received either 1 or 3 microg/kg pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) or placebo and then donated platelets 10 to 15 days later. One hundred sixty-six of these platelet concentrates were then transfused to 120 patients with platelets counts 25 x 10(9)/L or lower. Pretransfusion platelet counts (11 x 10(9)/L) were similar for recipients of placebo-derived and PEG-rHuMGDF-derived platelets. Early after transfusion, the median platelet count increment was higher in patients receiving PEG-rHuMGDF-derived platelets: 19 (range, -12-66) x 10(9)/L, 41 (range, 5-133) x 10(9)/L, and 82 (range, -4-188) x 10(9)/L for placebo-, 1-microg/kg-, and 3-micro/kg-derived platelets, respectively. This difference was maintained 18 to 24 hours after transfusion. Transfusion-free intervals were 1.72, 2.64, and 3.80 days for the recipients of the placebo-, 1-microg/kg-, and 3-micro/kg-derived platelets, respectively. The rate of transfusion-related adverse events was not different in recipients of placebo-derived and PEG-rHuMGDF-derived platelets. Therefore, when transfused into patients with thrombocytopenia, platelets collected from healthy donors undergoing thrombopoietin therapy were safe and resulted in significantly greater platelet count increments and longer transfusion-free intervals than platelets obtained from donors treated with placebo.  (+info)

HIV transmissions from a window-period platelet donation. (5/44)

Recently, blood centers began investigational testing for HIV RNA by pooled nucleic acid testing (NAT). A 35-year-old frequent platelet donor tested HIV p24 antigen positive, antibody negative before implementation of NAT. He made 2 platelet donations (day -4 and -11) immediately before testing positive for HIV. The donor's HIV seroconversion was monitored, and stored samples were tested retrospectively for HIV RNA. Platelet recipients were tested for HIV infection. The day -4 sample tested positive for HIV RNA by pooled and individual sample NAT. The day -11 sample tested negative for HIV RNA by both NAT tests. The 2 recipients of the day -4 platelets tested HIV RNA and p24 antigen positive. The recipient of the day -11 platelets could not be tested because he had died. HIV NAT would have prevented transmission of HIV had it been available at the time of this donor's HIV seroconversion.  (+info)

Evaluation of an automated preanalytical robotic workstation at two academic health centers. (6/44)

BACKGROUND: Purchase of automated systems in today's clinical laboratory needs justification based on demonstrable improvements in efficiency and a sound payback model. Few studies provide information on laboratory automation that focuses on the preanalytical portion of specimen processing. METHODS: We recently evaluated an automated preanalytical processing unit (GENESIS FE500) at two academic health centers. This preanalytical unit processes blood specimens through automated specimen sorting, centrifugation, decapping, labeling, aliquoting, and placement of the processed specimen in the analytical rack. We quantified the output of the FE500 by processing >3000 barcode-labeled specimens according to a protocol designed to test all of the features of this automated specimen-processing unit. RESULTS: Depending on the batch size, aliquot number requested, and percentage of tubes that required centrifugation, the mean system output performance varied between 93 and 502 total tubes/h. Throughput increased when the batch size expanded from 40 or 100 samples (mean = 211 total tubes processed/h) to batch sizes of 200 and 300 tubes (mean = 474 total tube processed/h). The GENESIS FE500 processed specimen tubes differing in size from 13 x 65 mm (width x height) to 16 x 100. At one site, the FE500 was operated by one person, compared with the three individuals required to perform the same tasks manually. Finally, the specimen-processing error rate determined at one of the institutions was significantly reduced. CONCLUSIONS: We conclude that the GENESIS FE500 effectively reduces the labor associated with specimen processing; decreases the number of laboratory errors that occur with specimen sorting, labeling, and aliquoting; and improves the integrity of specimen handling throughout the steps of specimen processing.  (+info)

Acute plateletpheresis and aprotinin reduces the need for blood transfusion following Ross operation. (7/44)

The effect of acute intraoperative plateletpheresis (25% platelet yield) in combination with intraoperative low-dose aprotinin (2 million units) on blood conservation was investigated in 18 young adult patients undergoing elective Ross operation. The results were compared with a group of 19 similar patients without plateletpheresis (control group). The hematological and coagulation parameters at admission and discharge were statistically similar in both groups. The total blood product transfusion requirements were significantly reduced in the plateletpheresis group compared with the control group (3.2 units and 5.1 units, respectively, P=0.036). The total blood donor exposure was also reduced significantly in the plateletpheresis group compared with the control group (3.2 and 6.9 donors/patient, respectively, P<0.001). The direct costs for the hospital for the plateletpheresis procedure, including costs for all blood products, were similar to those for blood products alone in the control group. In summary, acute plateletpheresis in combination with low-dose aprotinin significantly reduces the blood product transfusions and blood donor exposures following the Ross operation; the treatment is cost-effective.  (+info)

Oncogenic and angiogenic growth factors accumulate during routine storage of apheresis platelet concentrates. (8/44)

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