Safety and collection efficiency with a lower transfusion threshold for extracorporeal photopheresis in adult patients with graft-versus-host disease.

BACKGROUND: Extracorporeal photopheresis (ECP) is an established treatment for graft-versus-host disease (GVHD). Various haematocrit thresholds have been used to trigger red blood cells transfusion prior to ECP. Moderate-to-severe GVHD is frequently complicated by anaemia; the safety and collection efficiency with a lower haematocrit for ECP is unknown. METHODS: We prospectively enrolled 26 consecutive adult GVHD patients with haematocrits between 25% and 28·9% who received ECP on the CELLEX system. Preprocedural transfusion was withheld. We monitored the adverse events and transfusions avoided. A complete blood cell count with differential was performed on preprocedural peripheral blood and buffy coat collected. Lymphocyte fold enrichment (LFE) was compared between this cohort and two historical control groups with haematocrits of 29% or higher. RESULTS: Red Blood Cells transfusion was avoided in the lower-haematocrit cohort without adverse events. The median LFE was 4·5 (95%CI, 3·1-5·7) in the lower-haematocrit cohort and 5·2 (95%CI, 4·1-6·5) in the higher-haematocrit CELLEX-treated control group. The median difference was 0·7 (95%CI, -0·3 to 2·0, P = 0·14). It could not be established that the lower-haematocrit cohort was non-inferior to the higher-haematocrit control group with a prespecified non-inferiority margin of 1·3. However, LFE was significantly higher in the lower-haematocrit cohort than the higher-haematocrit UVAR XTS-treated control group (P < 0·01). CONCLUSION: Buffy coat can be collected for ECP using CELLEX in GVHD patients with a haematocrit of 25% or higher, with a collection efficiency superior to that in patients with higher haematocrits but treated using UVAR XTS. No increase in adverse events was observed at these lower haematocrits.

Adverse events in platelet apheresis donors: A multivariate analysis in a hospital-based program.

OBJECTIVES: This study was designed to review the incidence of adverse events during nearly 20,000 apheresis procedures over a 4-year period in a hospital-based program. METHODS: Data were obtained from a review of: (1) apheresis adverse event forms (2) hospital or emergency room medical records (3) the databank for donor and procedure-related variables. Adverse events during or after the apheresis procedures were analyzed according to the following categories: (1) complications related to citrate toxicity; (2) hypotensive or vasovagal episodes; (3) complications or symptoms consistent with coronary ischemia; (4) complications related to percutaneous needle insertion, and (5) miscellaneous procedure-related events or nonspecific symptoms. Serious adverse events were categorized as persistent or severe hemodynamic changes as well as other events that required further medical evaluation. RESULTS: Of 19,736 apheresis procedures, 159 (0.81%) were associated with adverse events. In 2,376 first-time donations, 26 (1.09%) developed adverse events compared to 133 (0.77%) of 17,360 repeat procedures (p = 0.10). Seventy (0.35%) of 159 donation-related adverse events involved hemodynamic or citrate-related complications and 73 (0.37%) involved venipuncture-related complications, of which 2 required subsequent neurologic consultation. The remaining 23 (0. 12%) adverse events involved procedure-related, nonspecific complications. Forty-seven (0.24%) of the 19,736 apheresis procedures were associated with serious adverse events (SAEs). Seven of these serious adverse events required admission to an emergency department, and 2 required hospitalization for further evaluation. Multivariate analysis revealed that apheresis machine model, donor gender and weight, the concomitant harvesting of plasma, the frequency of donation, and citrate-related symptoms (e.g. paresthesias) were independently associated with severe hypotensive reactions. CONCLUSIONS: Apheresis procedures have a 150-fold higher incidence of SAEs requiring hospitalization compared to whole blood donation. Identification of donors at risk for complications can facilitate modification of the apheresis procedure in order to reduce the likelihood of adverse events. Although our study did not demonstrate a cause-effect relationship between platelet donation and the development of acute coronary syndromes, underlying cardiovascular disease was detected in 2 donors during or after the apheresis who were otherwise asymptomatic.

Economic impact of donor platelet count and platelet yield in apheresis products: relevance for emerging issues in platelet transfusion therapy.

INTRODUCTION: We analyzed donor platelet counts and platelet product yields in 708 consecutive platelet aphereses in our program in order to define the importance of this relationship for emerging issues in platelet transfusion therapy. METHODS: Aphereses performed on the Spectra 3.6 (COBE, Lakewood. Colo.) the CS-3000 Plus (Fenwall-Baxter, Deerfield, Ill.) were analyzed. RESULTS: Mean platelet count was 237+/-49x10(3)/mm3 (mean +/- SD), and mean yield was 4.24+/-1. 09x10(11) platelets. Eigthy-five (12%) procedures generated less that 3x10(11) platelets. Only thirty-eight (5.4%) procedures yielded >/=6x10(11) platelets, so that 'split products' could be obtained. Platelet yields were primarily related to the biologic contribution (baseline platelet count) of the donor. Procedure parameters selected for harvest, and the efficiency of the device also had a significant, but less important role in determining the final platelet yield. An increase in mean donor platelet count achieved with Mpl ligand therapy from 240,000 to 320,000/mm3 would reduce the cost from USD 378 to 267 for each apheresis product, since the fraction of split products would exceed 50% of apheresis procedures. CONCLUSION: Increasing the donor platelet count would have a significant economic impact on platelet apheresis programs, as well as important clinical consequences for the role of platelet apheresis products in future transfusion strategies.

Prevalence of HLA sensitization in female apheresis donors.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is a serious complication of plasma-containing blood components. Studies have implicated HLA antibodies along with biologically active lipids in stored blood in the pathogenesis of TRALI. It has been proposed that the exclusion of HLA-untested, multiparous donors of plasma-rich components, including plasma and single-donor apheresis platelets, would substantially reduce the risk of TRALI. STUDY DESIGN AND METHODS: To investigate the feasibility of such an exclusion, 332 female plateletpheresis donors with a record of over 9000 donations, none of which were associated with TRALI, were studied. RESULTS: Seventeen percent of female donors demonstrated HLA sensitization. Parity and HLA sensitization were significantly correlated (p<0.0001), with sensitized donors having an average of 2.9 (+/- 0.6 95% CI) prior pregnancies and unsensitized donors having an average of 1.8 (+/- 0.2 95% CI) prior pregnancies. The percentage of HLA-sensitized women with 0, 1 to 2, and > or = 3 pregnancies was 7.8, 14.6, and 26.3, respectively. CONCLUSION: These findings confirm the hypothesis that multiparous women (> or = 3 pregnancies) represent an increased potential risk for TRALI. However, the exclusion of multiparous plateletpheresis donors would eliminate one-third of our female donor pool. Screening such donors for HLA sensitization may represent the optimal approach for identifying donors at risk for causing TRALI, but this still would result in the deferral of 8 percent of female plateletpheresis donors. At present, prospective screening to identify donors at risk for causing TRALI is not justified.

Granulocyte collection efficiency and yield are enhanced by the use of a higher interface offset during apheresis of donors given granulocyte-colony-stimulating factor.

BACKGROUND: Trials evaluating granulocyte transfusions for therapy of febrile neutropenia demonstrated mixed clinical results, which may in part be due to the low neutrophil cell dose of the transfused components. To optimize the latter variable, the effect of various interface offset (IO) settings during apheresis on granulocyte collection efficiency (GCE) and yield was determined in normal donors given granulocyte-colony-stimulating factor (G-CSF). STUDY DESIGN AND METHODS: Seventeen donors underwent 44 granulocyte collections performed with a continuous-flow blood cell separator with hetastarch infusion after stimulation with G-CSF (5 micrograms/kg/day). Apheresis was performed alternatively using one of three IO settings: IO = 15 (Group 1, n = 16), IO = 25 (Group 2, n = 12), and IO = 35 (Group 3, n = 13). The GCE and yield and changes in donor platelet count, hematocrit (Hct), and red cell (RBC) volume of the components were compared among the three groups. RESULTS: The mean GCE was greater (p = 0.006) during apheresis at an IO setting of 35 (60 +/- 12%) than at an IO setting of 15 (40 +/- 17%). The mean granulocyte yield (x10(10) per procedure was 10.8 +/- 2.95 at an IO setting of 35 and 7.73 +/- 4.02 at an IO setting of 15 (p = 0.08). In a multivariate linear regression model, factors independently associated with granulocyte yield were the absolute granulocyte count (r = 0.73, p < 0.001) and blood volume of the donor (r = 0.54, p = 0.001) before the procedure and the use of an IO setting of 35 (r = 0.50, p = 0.002). There was no significant difference among the three groups in the decrement in donor platelet count or Hct with apheresis, although the mean RBC volume was greater in Group 3. CONCLUSION: Granulocyte apheresis at an IO setting of 35 rather than 15 resulted in a significant increase in the GCE. The use of an IO setting of 35 during apheresis was an independent factor associated with granulocyte yield in the multivariate model. Donor safety was not compromised by collecting granulocytes at the higher IO setting.

Experience of a combined apheresis, blood collection, and blood transfusion unit in a large tertiary care medical center.

The Barnes Hospital Apheresis Blood Collection and Blood Transfusion Unit is part of Barns Hospital Blood Bank. Because of its size and complexity, we report our experience which may be useful to administrators and physicians involved in the planning or management of similar services. From 1985 through 1988 we collected platelets from 1,976 different donors, the majority of which (87%) were community donors. Sixty-nine percent of 1,976 donors donated in 1988 an average of 4.9 times. Of 6,568 apheresis products collected. 1.1% were discarded because of positive screening tests and 0.7% were discarded because of outdating or presence of fibrin clot. In 1988 a total of nine cell separators were used. All donor apheresis were done with seven blood separators, and on average a separator produced an apheresis product every 4.5 worked hours. All therapeutic apheresis (338) were done on two separators. Most of them (88%) were performed during work hours. In 1988 donor and therapeutic apheresis were done by 17 1/2 full-time employees (FTEs) during work hours. Considering the Workload Unit Value per procedure given by the College of American Pathologists (CAP) and that each FTE worked 1,864 hours per year, the worked hour productivity for donor and therapeutic apheresis was 78.2%. Blood collections, therapeutic bleeds, and outpatient transfusions (1,127, 114 and 1,745 respectively) were accomplished by two FTEs, for a worked hour productivity of 35.5%. Because 95.1% of total worked units was produced by efficient donor and therapeutic apheresis activities, overall efficiency remained high at 73.8%.