The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Petra Stohlawetz - One of the best experts on this subject based on the ideXlab platform.
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effects of nitric oxide on platelet activation during Plateletpheresis and in vivo tracking of biotinylated platelets in humans
Transfusion, 1999Co-Authors: Petra Stohlawetz, Hansgeorg Eichler, Michaela Horvath, Thomas Pernerstorfer, H Nguyen, Barbara Vondrovec, A Robisch, S Spitzauer, Bernd JilmaAbstract:BACKGROUND: The use of platelet transfusions has risen considerably over the last few years, which leads to the collection and transfusion of a greater number of donor Plateletpheresis units. Plateletpheresis activates platelets in platelet concentrates, which determines the degree of the storage lesion subsequently observed. STUDY DESIGN AND METHODS: As nitric oxide (NO) is a potent inhibitor of platelet aggregation and activation, a placebo-controlled crossover trial was performed in healthy young male volunteers to determine whether the NO-donating compound, sodium nitroprusside (SNP), decreases platelet activation during apheresis and whether activated (p-selectin+) platelets circulate in vivo after transfusion. The study also investigated whether nonradioactive biotin labeling of apheresis platelets is feasible for the study of platelet recovery after transfusion in humans. RESULTS: Platelet activation increased after Plateletpheresis in the platelet components, but SNP did not inhibit platelet activation during apheresis, as measured by the percentage of p-selectin expression and the secretion of soluble p-selectin and RANTES. Only a minor increase in p-selectin+ platelets was seen in peripheral blood at 60 minutes after transfusion of the platelets, a rise that was considerably less than that calculated in p-selectin+ platelets if they all were recovered as activated platelets after transfusion. Biotin-labeled platelets averaged 1.5 percent at 10 minutes after transfusion and increased slowly to 2.6 and 3.4 percent after 60 minutes and 24 hours, respectively (p<0.05). CONCLUSION: SNP does not decrease platelet activation during apheresis and subsequent storage, and only a minor proportion of activated (p-selectin+) platelets circulate after transfusion in men. Moreover, biotin labeling of PCs can safely be used in humans for the study of platelet recovery after transfusion, and measuring recovery at 1 hour may lead to an underestimation of the true recovery when activated platelets are transfused.
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safety issues of Plateletpheresis comparison of the effects of two cell separators on the activation of coagulation fibrinolysis and neutrophils and on the formation of neutrophil platelet aggregates
Transfusion, 1999Co-Authors: Petra Stohlawetz, Stylianos Kapiotis, Dagmar Seidl, Nicole Hergovich, Maria Zellner, Hansgeorg Eichler, G Stiegler, Gerda Leitner, P Hocker, Bernd JilmaAbstract:BACKGROUND: Although many donors undergo repeated Plateletpheresis, data on the consequences of Plateletpheresis for the donor's health remain scarce. Thus, the effect of Plateletpheresis on the activation of coagulation, fibrinolysis, and neutrophils was investigated. STUDY DESIGN AND METHODS: Part 1: Sixteen healthy men were randomly assigned to undergo Plateletpheresis on a cell separator (AMICUS, Fenwal Baxter; or MCS 3p, Haemonetics). The effects of Plateletpheresis on plasma levels of prothrombin fragment (F1+2), d-dimer, plasmin-plasmin inhibitor (PPI) complexes, and plasminogen activator inhibitor (PAI-1); on the activation of neutrophils (% l-selectin+); and on the frequency of platelet-neutrophil aggregates (% CD41 + neutrophils) were compared. Part 2: Ten healthy men received infusions of ACD-A and placebo without apheresis in a randomized, double-blind crossover study to control for the pharmacologic effects of citrate. RESULTS: Part 1: No change in F1+2 occurred (p>0.05), which indicated that Plateletpheresis did not enhance coagulation. Levels of d-dimer, PPI, and PAI-1 decreased over time on the AMICUS (p 0.05), but it decreased the percentage of CD41+ neutrophils (p<0.003). An approximately 80-percent drop in mononuclear cells was observed in the extracorporeal circulation of the AMICUS (p<0.001 vs. baseline and p = 0.005 vs. MCS 3p), and circulating lymphocyte and monocyte counts decreased concomitantly. Part 2: Infusion of ACD-A slightly decreased d-dimer levels (p<0.05), and both infusions decreased the circulating lymphocyte counts. CONCLUSION: Plateletpheresis can be regarded as safe with respect to the activation of coagulation or neutrophils. The consequences for the donor's health of the decrease in d-dimer, PPI, and PAI-1 may deserve further investigation.
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increase in endogenous thrombopoietin in healthy donors after automated Plateletpheresis
Transfusion, 1998Co-Authors: Markus Dettke, Petra Stohlawetz, G Stiegler, Gerda Leitner, P Hocker, M Hlousek, M Kurz, Konrad Rosskopf, Nina Worel, Simon PanzerAbstract:BACKGROUND: Thrombopoietin (TPO) is a key cytokine involved in the regulation of megakaryocytopoiesis and platelet production. The aim of the present study was to test whether platelet donation is associated with changes in the serum TPO levels in healthy donors undergoing Plateletpheresis. STUDY DESIGN AND METHODS: The study group consisted of 23 healthy donors undergoing single-donor Plateletpheresis for the first time. Serum TPO levels and platelet counts were determined before platelet collection, at the end of apheresis, and for 4 days thereafter. Serum TPO levels were determined by a TPO-specific enzyme- linked immunosorbent assay. RESULTS: In relationship to platelet donation, serum TPO levels showed a temporary increase from baseline levels of 69.2 +/− 7.1 pg per mL to 117 +/− 6.8 pg per mL 2 days after Plateletpheresis (p < 0.05). Further evaluation revealed a decline in serum TPO levels as platelet counts increased. Female donors showed a delayed normalization of circulating platelet numbers and serum TPO levels as compared to male donors. There was no significant correlation between serum TPO levels and the absolute platelet number during normalization of the donors' platelet counts after Plateletpheresis. CONCLUSION: Single-donor Plateletpheresis results in a temporary increase in serum TPO levels in healthy platelet donors, which may be part of a compensatory response-boosting megakaryocytopoiesis after platelet collection.
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Measurement of the levels of reticulated platelets after Plateletpheresis to monitor activity of thrombopoiesis.
Transfusion, 1998Co-Authors: Petra Stohlawetz, G Stiegler, P Hocker, Bernd Jilma, Markus Dettke, Simon PanzerAbstract:BACKGROUND: Little is known about the effects of long-term Plateletpheresis on the donors' health. The aim of this study was to examine the effect of Plateletpheresis on the time course of reticulated platelet counts as an estimate for thrombopoiesis. STUDY DESIGN AND METHODS: The effect of moderate platelet depletion on the thrombopoietic capacity was evaluated prospectively by the measurement of reticulated platelets before and after Plateletpheresis and on the following 4 days. Donors undergoing Plateletpheresis for the first time were compared to those donating platelets every other week for more than 18 months. RESULTS: The median levels of reticulated platelets were significantly lower in frequent donors than in new donors. In new donors, there was a transient increase in the median levels of reticulated platelets on Day 3 after apheresis, and baseline values were reached again on Day 4. On the contrary, in repeat donors, there was a sustained rise in the percentage of reticulated platelets from Days 1 through 4. However, this increase in reticulated platelet counts was still less than that seen in new donors. There was no difference in the peripheral blood platelet counts in the two groups at any time point. CONCLUSION: These findings suggest that repeat platelet donation might lead to a relative exhaustion of thrombopoiesis, as evidenced by the low levels of reticulated platelets exhibited by repeat donors. The reticulated platelet count can be used to monitor the thrombopoietic capacity of long-term platelet donors.
John M Gansner - One of the best experts on this subject based on the ideXlab platform.
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severe cd4 t cell lymphopenia is not observed in frequent Plateletpheresis donors collected on the fenwal amicus
Transfusion, 2019Co-Authors: John M Gansner, Mona Papari, Jake Goldstein, Rachel A Gaufberg, Donna Neuberg, Robert S Makar, Richard M KaufmanAbstract:BACKGROUND: In a recent study, we determined that 30% of frequent Plateletpheresis donors collected using the Trima Accel Automated Blood Collection System (Terumo BCT) had a CD4+ T-cell count below 200 cells/μL. Whether CD4+ T-cell lymphopenia is associated with donation using other Plateletpheresis instruments is unknown. STUDY DESIGN AND METHODS: We obtained blood samples from 30 current frequent Fenwal Amicus Plateletpheresis donors. All participants had made 20 to 24 Plateletpheresis donations in the most recent 365-day period, and all had previously donated over 50 times on the Fenwal Amicus instrument. Blood samples were analyzed to determine blood counts, including CD4+ and CD8+ counts. RESULTS: Of 30 study participants, none had a CD4+ count below 200 cells/μL. There was one participant with a CD4+ count between 200 and 300 cells/μL. This individual was over the age of 55 and had a history of more than 300 lifetime Plateletpheresis sessions. One participant had a CD8+ count below the lower limit of normal (125 cells/μL) and a normal CD4+ count. CONCLUSION: We did not detect severe CD4+ lymphopenia in frequent platelet donors undergoing Plateletpheresis with the Fenwal Amicus. Since the Fenwal Amicus does not incorporate a leukoreduction system chamber, this finding supports the hypothesis that such chambers-found in the Trima Accel instrument-contribute to CD4+ lymphopenia in frequent platelet donors.
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cd4 t cell lymphopenia in frequent platelet donors who have ceased platelet donation for at least 1 year
Transfusion, 2019Co-Authors: Mahboubeh Rahmani, Brooke M Fortin, Donna Neuberg, Richard M Kaufman, Nancy Berliner, Nicolas C Issa, John M GansnerAbstract:BACKGROUND: We recently discovered that 30% of current frequent apheresis platelet donors in a study at our donor center had CD4+ counts below 200 cells/μL. How long CD4+ lymphopenia persists after ceasing Plateletpheresis is unknown. Whether there are infectious or other complications in former frequent donors that could relate to CD4+ lymphopenia is also unknown. STUDY DESIGN AND METHODS: We mailed a letter to former frequent apheresis platelet donors who had not donated platelets for at least 12 months. Frequent donation was defined as 20 to 24 Plateletpheresis sessions in at least one 365-day period starting in 2011. Donors who expressed interest in the study were contacted to schedule a study visit. Participants in the study provided a blood sample and completed a health questionnaire that included questions about opportunistic infections and malignancies. RESULTS: Of 50 potential study candidates who were mailed a letter, 15 participated in the study. There were 2 participants with CD4+ counts below 200 cells/μL, one of whom had prior counts that documented a small improvement with cessation of Plateletpheresis. Three participants had counts between 200 and 300 cells/μL. No study participant had a history of an opportunistic infection or a malignancy associated with immune dysregulation. CONCLUSION: We detected CD4+ lymphopenia in former frequent apheresis platelet donors who had ceased platelet donation for more than 1 year. There was no evidence that the CD4+ lymphopenia predisposes to opportunistic infections or to malignancies associated with immune dysregulation.
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Plateletpheresis associated lymphopenia in frequent platelet donors
Blood, 2019Co-Authors: John M Gansner, Mahboubeh Rahmani, Helena A Jonsson, Brooke M Fortin, Idayat Brimah, Martha Ellis, Robin Smelandwagman, Zhihan J Li, Jason M Schenkel, Michael B BrennerAbstract:Over one million apheresis platelet collections are performed annually in the United States. After two healthy Plateletpheresis donors were incidentally found to have low CD4+ T-lymphocyte counts, we investigated whether Plateletpheresis causes lymphopenia. We conducted a cross-sectional, single-center study of platelet donors undergoing Plateletpheresis with the Trima Accel, which removes leukocytes continuously with its leukoreduction system chamber. We recruited three groups of platelet donors based on the total number of Plateletpheresis sessions in the prior 365 days: 1-2, 3-19, or 20-24. CD4+ T-lymphocyte counts were below 200 cells/µL in 0/20 donors in the 1-2 sessions group, 2/20 donors in the 3-19 group and 6/20 donors in the 20-24 group (P=0.019). CD8+ T-lymphocyte counts were low in 0/20 donors in the 1-2 group, 4/20 donors in the 3-19 group, and 11/20 donors in the 20-24 group (P
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Plateletpheresis associated lymphopenia in frequent platelet donors
Blood, 2019Co-Authors: John M Gansner, Mahboubeh Rahmani, Helena A Jonsson, Brooke M Fortin, Idayat Brimah, Martha Ellis, Robin Smelandwagman, Michael B Brenner, Jason M Schenkel, Revital YefidofffreedmanAbstract:More than 1 million apheresis platelet collections are performed annually in the United States. After 2 healthy Plateletpheresis donors were incidentally found to have low CD4+ T-lymphocyte counts, we investigated whether Plateletpheresis causes lymphopenia. We conducted a cross-sectional single-center study of platelet donors undergoing Plateletpheresis with the Trima Accel, which removes leukocytes continuously with its leukoreduction system chamber. We recruited 3 groups of platelet donors based on the total number of Plateletpheresis sessions in the prior 365 days: 1 or 2, 3 to 19, or 20 to 24. CD4+ T-lymphocyte counts were <200 cells per microliter in 0/20, 2/20, and 6/20 donors, respectively (P = .019), and CD8+ T-lymphocyte counts were low in 0/20, 4/20, and 11/20 donors, respectively (P < .001). The leukoreduction system chamber's lymphocyte-extraction efficiency was ∼15% to 20% for all groups. Immunophenotyping showed decreases in naive CD4+ T-lymphocyte and T helper 17 (Th17) cell percentages, increases in CD4+ and CD8+ effector memory, Th1, and regulatory T cell percentages, and stable naive CD8+ and Th2 percentages across groups. T-cell receptor repertoire analyses showed similar clonal diversity in all groups. Donor screening questionnaires supported the good health of the donors, who tested negative at each donation for multiple pathogens, including HIV. Frequent Plateletpheresis utilizing a leukoreduction system chamber is associated with CD4+ and CD8+ T-cell lymphopenia in healthy platelet donors. The mechanism may be repeated extraction of these cells during Plateletpheresis. The cytopenias do not appear to be harmful.
Bernd Jilma - One of the best experts on this subject based on the ideXlab platform.
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effects of nitric oxide on platelet activation during Plateletpheresis and in vivo tracking of biotinylated platelets in humans
Transfusion, 1999Co-Authors: Petra Stohlawetz, Hansgeorg Eichler, Michaela Horvath, Thomas Pernerstorfer, H Nguyen, Barbara Vondrovec, A Robisch, S Spitzauer, Bernd JilmaAbstract:BACKGROUND: The use of platelet transfusions has risen considerably over the last few years, which leads to the collection and transfusion of a greater number of donor Plateletpheresis units. Plateletpheresis activates platelets in platelet concentrates, which determines the degree of the storage lesion subsequently observed. STUDY DESIGN AND METHODS: As nitric oxide (NO) is a potent inhibitor of platelet aggregation and activation, a placebo-controlled crossover trial was performed in healthy young male volunteers to determine whether the NO-donating compound, sodium nitroprusside (SNP), decreases platelet activation during apheresis and whether activated (p-selectin+) platelets circulate in vivo after transfusion. The study also investigated whether nonradioactive biotin labeling of apheresis platelets is feasible for the study of platelet recovery after transfusion in humans. RESULTS: Platelet activation increased after Plateletpheresis in the platelet components, but SNP did not inhibit platelet activation during apheresis, as measured by the percentage of p-selectin expression and the secretion of soluble p-selectin and RANTES. Only a minor increase in p-selectin+ platelets was seen in peripheral blood at 60 minutes after transfusion of the platelets, a rise that was considerably less than that calculated in p-selectin+ platelets if they all were recovered as activated platelets after transfusion. Biotin-labeled platelets averaged 1.5 percent at 10 minutes after transfusion and increased slowly to 2.6 and 3.4 percent after 60 minutes and 24 hours, respectively (p<0.05). CONCLUSION: SNP does not decrease platelet activation during apheresis and subsequent storage, and only a minor proportion of activated (p-selectin+) platelets circulate after transfusion in men. Moreover, biotin labeling of PCs can safely be used in humans for the study of platelet recovery after transfusion, and measuring recovery at 1 hour may lead to an underestimation of the true recovery when activated platelets are transfused.
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safety issues of Plateletpheresis comparison of the effects of two cell separators on the activation of coagulation fibrinolysis and neutrophils and on the formation of neutrophil platelet aggregates
Transfusion, 1999Co-Authors: Petra Stohlawetz, Stylianos Kapiotis, Dagmar Seidl, Nicole Hergovich, Maria Zellner, Hansgeorg Eichler, G Stiegler, Gerda Leitner, P Hocker, Bernd JilmaAbstract:BACKGROUND: Although many donors undergo repeated Plateletpheresis, data on the consequences of Plateletpheresis for the donor's health remain scarce. Thus, the effect of Plateletpheresis on the activation of coagulation, fibrinolysis, and neutrophils was investigated. STUDY DESIGN AND METHODS: Part 1: Sixteen healthy men were randomly assigned to undergo Plateletpheresis on a cell separator (AMICUS, Fenwal Baxter; or MCS 3p, Haemonetics). The effects of Plateletpheresis on plasma levels of prothrombin fragment (F1+2), d-dimer, plasmin-plasmin inhibitor (PPI) complexes, and plasminogen activator inhibitor (PAI-1); on the activation of neutrophils (% l-selectin+); and on the frequency of platelet-neutrophil aggregates (% CD41 + neutrophils) were compared. Part 2: Ten healthy men received infusions of ACD-A and placebo without apheresis in a randomized, double-blind crossover study to control for the pharmacologic effects of citrate. RESULTS: Part 1: No change in F1+2 occurred (p>0.05), which indicated that Plateletpheresis did not enhance coagulation. Levels of d-dimer, PPI, and PAI-1 decreased over time on the AMICUS (p 0.05), but it decreased the percentage of CD41+ neutrophils (p<0.003). An approximately 80-percent drop in mononuclear cells was observed in the extracorporeal circulation of the AMICUS (p<0.001 vs. baseline and p = 0.005 vs. MCS 3p), and circulating lymphocyte and monocyte counts decreased concomitantly. Part 2: Infusion of ACD-A slightly decreased d-dimer levels (p<0.05), and both infusions decreased the circulating lymphocyte counts. CONCLUSION: Plateletpheresis can be regarded as safe with respect to the activation of coagulation or neutrophils. The consequences for the donor's health of the decrease in d-dimer, PPI, and PAI-1 may deserve further investigation.
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Measurement of the levels of reticulated platelets after Plateletpheresis to monitor activity of thrombopoiesis.
Transfusion, 1998Co-Authors: Petra Stohlawetz, G Stiegler, P Hocker, Bernd Jilma, Markus Dettke, Simon PanzerAbstract:BACKGROUND: Little is known about the effects of long-term Plateletpheresis on the donors' health. The aim of this study was to examine the effect of Plateletpheresis on the time course of reticulated platelet counts as an estimate for thrombopoiesis. STUDY DESIGN AND METHODS: The effect of moderate platelet depletion on the thrombopoietic capacity was evaluated prospectively by the measurement of reticulated platelets before and after Plateletpheresis and on the following 4 days. Donors undergoing Plateletpheresis for the first time were compared to those donating platelets every other week for more than 18 months. RESULTS: The median levels of reticulated platelets were significantly lower in frequent donors than in new donors. In new donors, there was a transient increase in the median levels of reticulated platelets on Day 3 after apheresis, and baseline values were reached again on Day 4. On the contrary, in repeat donors, there was a sustained rise in the percentage of reticulated platelets from Days 1 through 4. However, this increase in reticulated platelet counts was still less than that seen in new donors. There was no difference in the peripheral blood platelet counts in the two groups at any time point. CONCLUSION: These findings suggest that repeat platelet donation might lead to a relative exhaustion of thrombopoiesis, as evidenced by the low levels of reticulated platelets exhibited by repeat donors. The reticulated platelet count can be used to monitor the thrombopoietic capacity of long-term platelet donors.
Susan F. Leitman - One of the best experts on this subject based on the ideXlab platform.
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probiotic associated high titer anti b in a group a platelet donor as a cause of severe hemolytic transfusion reactions
Transfusion, 2009Co-Authors: Jennifer Danieljohnson, Susan F. Leitman, Harvey G Klein, Harvey J Alter, Agnes Leestroka, Phillip Scheinberg, Jeremy Pantin, Karen QuillenAbstract:BACKGROUND: Hemolytic transfusion reactions (HTRs) can occur with transfusion of platelets (PLTs) containing ABO-incompatible plasma. Reported cases have involved group O donors. Two cases of PLT-mediated HTRs associated with the same group A Plateletpheresis component, collected from a donor taking high doses of probiotics are reported. CASE REPORT: Case 1 was a 40-year-old 69-kg group B stem cell transplant patient who received one-half of a group A Plateletpheresis component. Severe back pain occurred 10 minutes into the transfusion, accompanied by anemia and hyperbilirubinemia. Case 2 was a 5-year-old 26-kg group B male with aplastic anemia who received the other half of the same Plateletpheresis component, volume reduced to 37 mL. Syncope occurred immediately after the transfusion, with laboratory evidence of hemolysis a few hours later. RESULTS: Serologic investigation of posttransfusion samples from both patients revealed positive direct antiglobulin tests: C3d only for Case 1 and immunoglobulin (Ig)G and C3d for Case 2; the eluates contained anti-B. The group A donor's anti-B titer was 16,384 at saline and IgG phases. Donor lookback revealed that the donor had donated 134 apheresis PLTs over many years. For 3 years, he had intermittently taken probiotics; 3 weeks before the index donation, he began taking three tablets of probiotics every day. Lookback of prior group B recipients uncovered a case of acute hemolysis that was not recognized at the time. The solubilized probiotic inhibited anti-B in vitro. CONCLUSION: Non–group O PLT donors can have high-titer anti-A or anti-B that might mediate HTRs, and probiotic ingestion in blood donors represents a novel mechanism of stimulating high-titer anti-B.
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pasteurella multocida bacteremia in asymptomatic Plateletpheresis donors a tale of two cats
Transfusion, 2007Co-Authors: Barbara J Bryant, Cathy Conrycantilena, Alice Ahlgren, Anthony Felice, David F Stroncek, Joan Gibble, Susan F. LeitmanAbstract:BACKGROUND: Bacterial contamination of platelet (PLT) concentrates occurs in 1 in 1000 to 1 in 3000 components and has been a leading cause of transfusion-associated morbidity and mortality. Two cases of Pasteurella multocida bacteremia in asymptomatic Plateletpheresis donors are reported. Clinical outcomes were profoundly different, emphasizing the importance of robust methods to detect bacterial contamination. CASE REPORTS: The first case occurred before the implementation of bacterial testing of PLTs. A Plateletpheresis component was collected from a 70-year-old man and transfused to an 88-year-old man, who developed rigors, tachycardia, and hypotension within 15 minutes of the start of the transfusion. Cardiopulmonary arrest ensued and he expired 6 hours after transfusion. Blood cultures collected after transfusion and cultures of the PLT component were positive for the presence of P. multocida. Investigation revealed that a feral cat had bitten the donor 100 minutes before his donation. He had not reported the event to the donor room staff. The second case involved a 74-year-old woman who developed a flulike syndrome 2 days after Plateletpheresis donation. P. multocida was isolated in routine bacterial culture of her PLT component. The donor had several feral cats, and although there was no history of bite or scratch, one cat liked to lick her hands, which were chapped from gardening. CONCLUSION: Occult bacteremia with P. multocida transmitted by feral cats was the source of PLT contamination in two cases over 3 years. Bacterial testing of PLTs is critical in the prevention of transfusion-acquired sepsis and allows the identification and treatment of asymptomatic bacteremic donors.
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randomized placebo controlled study of oral calcium carbonate supplementation in Plateletpheresis ii metabolic effects
Transfusion, 2003Co-Authors: Charles D Bolan, Stacey A Cecco, Yu Ying Yau, Robert Wesley, Jaime M Oblitas, Nadja N Rehak, Susan F. LeitmanAbstract:BACKGROUND: The metabolic effects of oral calcium (Ca) supplementation during Plateletpheresis were evaluated in a randomized, placebo-controlled trial. STUDY DESIGN AND METHODS: Twenty-three donors underwent four Plateletpheresis procedures each, receiving in random order, elemental Ca (Ca) 1 or 2 g orally, or a corresponding placebo, 30 minutes before donation. Ten of these donors underwent a fifth procedure using a 4-g Ca dose. All procedures were performed at a fixed citrate infusion rate of 1.5 mg per kg per minute. RESULTS: Oral Ca induced dose-sensitive changes in parathyroid hormone (iPTH), total (tCa), and ionized (iCa) calcium levels. Compared to placebo, the greatest improvement in tCa and iCa levels occurred after the 2-g Ca dose (tCa of 73, 89, and 25% above placebo levels at 60 min, using 1, 2, and 4 g of oral Ca, respectively). Twenty-four hours after apheresis, serum tCa and iCa levels were higher, and iPTH levels lower, in donors who received oral Ca rather than placebo. Marked increases in urinary Ca and magnesium (Mg) excretion occurred at the completion of apheresis, were unaffected by Ca dose, and returned to baseline within 24 hours. Plateletpheresis also induced significant changes in serum alkaline phosphatase, 1,25-dihydroxyvitamin D, and osteocalcin levels immediately and at 24 hours after apheresis. CONCLUSION: Plateletpheresis induces marked acute metabolic effects, with sustained changes evident up to 24 hours after the completion of apheresis. Oral Ca supplementation exerts a significant but clinically modest impact on selected laboratory variables associated with these effects. Further studies are indicated to examine the long-term impact of Plateletpheresis, with or without Ca supplementation, on donor Ca balance and bone density.
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comprehensive analysis of citrate effects during Plateletpheresis in normal donors
Transfusion, 2001Co-Authors: Charles D Bolan, Stacey A Cecco, Jaime M Oblitas, Nadja N Rehak, Sarah E Greer, Susan F. LeitmanAbstract:BACKGROUND: Although Plateletpheresis procedures are generally well tolerated, the clinical and metabolic consequences associated with rapid infusion of up to 10 g of citrate are underappreciated, and a comprehensive description of these events is not available. STUDY DESIGN AND METHODS: Clinical and laboratory changes were studied in seven healthy donors undergoing three 90-minute Plateletpheresis procedures each, at continuous, fixed citrate infusion rates of 1.1, 1.4, and 1.6 mg per kg per minute. RESULTS: Serum citrate levels increased markedly with increasing citrate infusion rates and did not achieve a stable plateau. As citrate infusion rates increased, the total volume processed and platelet yields also increased, but donor symptoms became more severe. Ionized calcium (iCa) and ionized magnesium (iMg) concentrations decreased markedly, by 33 and 39 percent below baseline, respectively, at a citrate rate of 1.6 mg per kg per minute. Intact parathyroid hormone levels were higher at 30 minutes than at later time points, despite progressive decreases in iCa and iMg. Urine citrate, calcium, magnesium, sodium, and potassium concentrations and urine pH values increased markedly during all procedures. CONCLUSION: Marked, progressive increases in serum citrate levels occur during Plateletpheresis, accompanied by symptomatic decreases in iCa and iMg, with significantly increased renal excretion of calcium, magnesium, and citrate.
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Sustained decreases in platelet count associated with multiple, regular Plateletpheresis donations.
Transfusion, 2001Co-Authors: Ellen Lazarus, Janet N. Browning, James Norman, Jaime Oblitas, Susan F. LeitmanAbstract:BACKGROUND: Transient but significant decreases in platelet counts have been documented to occur in donors undergoing single and serial short-term Plateletpheresis collections. The effect of long-term regular Plateletpheresis on donor platelet counts has not been characterized. STUDY DESIGN AND METHODS: A retrospective study was performed to evaluate the effects of long-term regular Plateletpheresis donation on donor platelet counts. A computerized database containing records of 11,464 apheresis collections from 939 donors over a 4-year period was queried for serial preapheresis platelet counts. Donors were categorized by sex, age, and cumulative number of donations. The average difference in platelet counts (mΔPC) between each donor's first and last platelet count during this period was calculated for each category. A subgroup of frequent donors was selected for analysis of mΔPC, using the baseline platelet count obtained before the first Plateletpheresis procedure. RESULTS: A significant and sustained decrease in platelet count was identified for all donation frequency categories. The frequency of donation correlated directly with decrease in platelet count for all but the highest-frequency donation group, in which deferrals for low platelet count blunted the extent of the mΔPC. A mean decrease of 40,000 per μL from baseline occurred in the frequent-donor subgroup. A total of 84 donors (9%) were deferred for low platelet count. The majority returned to donate successfully after temporary deferral. CONCLUSIONS: Regular Plateletpheresis donors develop sustained decreases in platelet count. However, clinically significant thrombocytopenia is unusual when rigorous ongoing review and prudent deferral policies are established and followed.
Reinhold Eckstein - One of the best experts on this subject based on the ideXlab platform.
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preparation of highly concentrated and white cell poor platelet rich plasma by Plateletpheresis
Vox Sanguinis, 2008Co-Authors: Robert Zimmermann, S Reske, P Metzler, Andreas Schlegel, J Ringwald, Reinhold EcksteinAbstract:Background and objectives Contaminating white blood cells (WBC) contribute remarkably to the overall growth factor content of locally applicable platelet-rich plasma (PRP) or platelet (PLT) gel and change the relative proportions of the contained growth factors. Materials and methods To study the independent effects of locally applicated highly concentrated PLTs, the development of preparations is needed that contain large amounts of PLTs and no or at least very few leucocytes. Therefore, 20 Plateletpheresis procedures were performed in voluntary blood donors to get highly concentrated and extremely WBC-poor Plateletpheresis concentrates. The degree of spontaneous PLT activation, the PLT aggregation response to agonists and the level of the growth factor TGF-beta1 (transforming growth factor beta1) were measured immediately after the donation and 1 day later. Results The concentrates contained 1.96 +/- 0.36 x 10e11 PLTs per unit in 55.2 +/- 7.9 ml, respectively. In comparison to the donors' blood, the PLT-enrichment factor was 15.3 +/- 5.4. At the same time, the concentrates contained extremely low residual numbers of WBCs (0.8 +/- 3.3 x 10e3/ml). The concentration of the growth factor TGF-beta1 was 743.2 +/- 243.9 ng/ml. On day 1, the PLT concentration and the TGF-beta1 content of the PLT concentrates had not decreased. Conclusions In summary, Plateletpheresis is suited to provide PRP products with higher concentrations of human platelets and platelet-derived growth factors than previously reported PRP preparation methods but with extremely low numbers of contaminating leucocytes.
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Plateletpheresis does not cause long standing platelet derived growth factor release into the donor blood
Transfusion, 2005Co-Authors: Robert Zimmermann, Daniela Loew, Volker Weisbach, Erwin Strasser, Juergen Ringwald, Juergen Zingsem, Reinhold EcksteinAbstract:BACKGROUND: Recently, long-standing elevations of soluble growth factors released from platelets (PLTs) after contact with artificial surfaces during dialysis were described. They could be jointly responsible for the high frequency of death from cardiovascular diseases in dialysis patients. There are no comparable data on the extent and the duration of a growth factor release by Plateletpheresis procedures. STUDY DESIGN AND METHODS: A total of 37 Plateletpheresis procedures were performed with two different devices. PLT-derived growth factor (PDGF) isoform AB, transforming growth factor (TGF)-beta1, and beta-thromboglobulin (beta-TG) were measured in the donors' plasma samples, and PLT activation and function were measured by cytometry and aggregometry before and after Plateletpheresis and 1 and 24 hours later. RESULTS: Before apheresis, the following mean plasma levels were found: beta-TG, 98.6 +/- 37.3 IU per mL; PDGF-AB, 71.5 +/- 38.5 pg per mL; and TGF-beta1, 2.24 +/- 0.80 ng per mL. At the end of the apheresis procedures, the mean PDGF-AB level had increased by a factor of 1.8 (p < 0.05). One hour later, the mean PDGF-AB level had normalized again. No significant change in the levels of beta-TG and TGF-beta1 was found by the apheresis procedures. There was no influence of the blood cell separator type on the results. CONCLUSION: Only a slight and rapidly reversible increase in soluble PDGF-AB was found during Plateletpheresis and no increase in soluble TGF-beta1 and beta-TG was found. This change should not be harmful to the donor.
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preparation of ffp as a by product of Plateletpheresis
Transfusion, 2002Co-Authors: J Zingsem, Robert Zimmermann, Volker Weisbach, Anke Glaser, Helena Bunkens, Reinhold EcksteinAbstract:BACKGROUND To reduce the production costs of single-donor platelets (SDPs), a study was conducted to investigate whether plasma collected as a by-product of Plateletpheresis satisfies the quality requirements for FFP without impairing the quality of the SDP component. STUDY DESIGN AND METHODS Ninety-two donors with platelet (PLT) counts <270 x 10(9) per L underwent Plateletpheresis using an automated cell separator (Spectra Apheresis System with the Leukoreduction System [LRS], Gambro BCT, Lakewood, CO). The machine was programmed to collect 3 x 10(11) PLTs in 250 mL of plasma with an additional unit of 350 mL of plasma or 3 x 10(11) PLTs in 250 mL of plasma without additional plasma in 10 procedures. FV and FVIII and residual RBCs, WBCs, and PLTs in the plasma were measured for quality control. RESULTS FV was 0.87 +/- 0.18 IU per mL, and FVIII was 1.32 +/- 0.48 IU per mL in the plasma components (n = 41). The recovery was 94.1 +/- 5.5 percent for FV and 102.2 +/- 9.5 percent for FVIII when compared with the donors' predonation values. Residual cells were 0.002 +/- 0.009 x 10(9) RBCs per L (n = 30), 12 +/- 6 x 10(9) PLTs per L (n = 30), and 0.32 +/- 0.37 x 10(6) WBCs per L (n = 92). CONCLUSIONS Using the automated cell separator and special software, it is possible to collect plasma as a by-product of Plateletpheresis that meets the properties requested for FFP without impairing the quality of the SDP components. The content of clotting factors is within the requested range for FFP. Residual cell counts are within all European and U.S. specifications for FFP, and the WBC content even satisfies the criteria for WBC-reduced blood components. The collection of FFP as a by-product does not cause any additional costs and thus helps to reduce the costs in preparing blood components.