PL03Obtaining Lawful Consent for Donation After Death

There is much current interest in the development and validation of a suitable blood test that could be used to screen all donors to avoid potential vCJD transmissions. In the interim there are other 'tissues' where abnormal prion could be assayed including those of the central nervous and lymphatic systems. Tonsil and spleen biopsies assessed for abnormal PrP are thought to be possible early indicators of infectivity. Although it is not reasonable to routinely obtain these biopsies from living blood donors, clearly there is a potential to obtain these tissues from donors who are deceased with appropriate consent. There are however problems associated with obtaining this tissue including the impact of the post-mortem investigation into cause of death, expertise in locating the tissue and the effects of rigor mortis. Also, given the assay result turnaround time, there are further complications associated with managing a positive test result including where organs or tissues from the donor have already been transplanted. These issues limit the suitable donor pool. The result is that only 25–50% of deceased tissue donors are indeed suitable. This population is being tested as a pilot within the NBS as a potential risk reduction measure.     

Proceedings of a consensus conference: the screening of blood donors for variant CJD

Since the identification, in 1996, of the first case of variant Creutzfeldt-Jakob disease (vCJD) in humans various approaches have been implemented and/or proposed to prevent this disease from being transfusion transmitted. In addition, a variety of possible laboratory-based approaches have been developed and will continue to be developed for the vCJD screening of blood donors. Various issues related to the implementation of such vCJD testing is likely to assume greater importance as diagnostic tests for vCJD becomes available for the potential screening of blood donors. The purpose of this Consensus Conference was to bring together international experts in an effort to determine which principles should guide the introduction of such testing. These experts provided the scientific and biological background of bovine spongiform encephalopathy (BSE) and vCJD, an understanding of their current epidemiology, as well as the ethical and legal issues that would impact on the implementation of a screening test for preventing the transfusion transmission of vCJD. This contentious issue is of potential considerable importance to transfusion medicine personnel worldwide, as well as to future recipients of allogeneic blood components.     

Variant Creutzfeldt‐Jakob disease in a transfusion recipient: coincidence or cause?

BACKGROUND: To date there have been four instances of infection transmitted through blood transfusions derived from individuals who later developed variant Creutzfeldt‐Jakob disease (vCJD). The identification of further transmission of vCJD through this route would have important implications for risk assessment and public health. STUDY DESIGN AND METHODS: Through the UK Transfusion Medicine Epidemiology Review (TMER) the fate of blood donations from individuals who develop vCJD is traced and recipients of labile components are identified. The details of recipients are cross‐checked with the register of vCJD cases held at the National CJD Surveillance Unit (NCJDSU) to identify any linkage between donors and recipients. In the reverse study, when individuals with vCJD are found to have a history of blood transfusion the donors of the transfused blood components are traced and their details cross‐checked with the vCJD register to identify any missed or unrecognized linkage between donors and recipients. CASE REPORT: A case of vCJD has been identified with a history of blood transfusion in infancy. The donors who provided the components transfused cannot be identified, but a blood donor known to have donated blood to another individual who subsequently developed vCJD could have been a donor to the index case. RESULTS: The at‐risk donor is alive 20 years after the relevant donation and continued to donate for some years, until identified as at risk, with 27 other blood components issued for use in patients, none of whom are known to have developed vCJD. CONCLUSION: Circumstantial evidence has raised the possibility that the case in this report represents a further instance of transfusion transmission of vCJD. However, detailed investigation indicates that the pattern of events may have occurred by chance and disease in this individual may have been caused by transmission of bovine spongiform encephalopathy infection, as is the presumed cause in other primary cases of vCJD.     

Variation in concentration of prion protein in the peripheral blood of patients with variant and sporadic Creutzfeldt-Jakob disease detected by dissociation enhanced lanthanide fluoroimmunoassay and flow cytometry

BACKGROUND: A highly sensitive dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA) and flow cytometry techniques have previously been developed and employed to characterize soluble cellular prion protein (PrP(c)) expression in whole blood and separated components from healthy adult blood donors. No previous studies with these techniques have evaluated the concentration and expression of PrP in the blood of patients with variant Creutzfeldt-Jakob disease (vCJD). STUDY DESIGN AND METHODS: For blood from vCJD patients, sporadic CJD (sCJD) patients, non-CJD neurological controls, and healthy adults, PrP(c) was measured by DELFIA and cell-associated PrP was measured by flow cytometry. RESULTS: DELFIA analysis identified a significant reduction in the concentration of PrP(c) in the whole blood of vCJD (p = 0.012) and non-CJD neurological patients (p = 0.0004) compared with healthy adults. A significant elevation was found in plasma PrP(c) in sCJD patients compared with healthy adult (p = 0.022) and neurological controls (p = 0.050). Flow cytometry found no significant differences between groups in expression of PrP on platelets and lymphocytes, nor in sensitivity of cellular PrP to proteinase K. Neurological controls show significantly less PrP on red cells than healthy adults. CONCLUSION: There are differences in free and cell-associated PrP found in blood of CJD patients and control groups, some of which might be useful with other tests in disease profiling as an aid to diagnoses.     

A highly sensitive immunoassay for the detection of prion‐infected material in whole human blood without the use of proteinase K

BACKGROUND: The causal association of variant Creutzfeldt‐Jakob disease (vCJD) with bovine spongiform encephalopathy has raised significant concerns for public health. Assays for vCJD infection are vital for the application of therapeutics, for the screening of organ donations, and to maintain a safe blood supply. Currently the best diagnostic tools for vCJD depend upon the detection of disease‐associated prion protein (PrP^Sc), which is distinguished from normal background PrP (PrP^C) by proteinase K (PK) digestion, which can also degrade up to 90% of the target antigen. STUDY DESIGN AND METHODS: A sandwich enzyme‐linked immunosorbent assay method was developed using unique antibodies for the detection of disease‐associated PrP in the absence of PK treatment. In combination with immunoprecipitation the assay was optimized for the detection of pathogenic PrP in large volumes of whole blood. RESULTS: Optimization of the assay allowed detection of 2 × 10⁴ LD₅₀ units/mL spiked in whole blood. Application of the assay to clinically relevant volumes enabled the detection of 750 LD₅₀ units/mL in 8 mL of whole blood. CONCLUSION: By combining the use of a unique antibody that selectively immunoprecipitates PrP^Sc with glycoform‐restrictive antibodies we have developed a rapid assay for vCJD infection that does not require any PK treatment to achieve high levels of specificity in whole human blood, the most challenging potential analyte. The sensitivity of detection of vCJD infection is greater than the equivalent of a more than 2.5 million‐fold dilution of infected brain, providing a highly sensitive immunoassay compatible with blood screening.     

Lack of evidence of transfusion transmission of Creutzfeldt-Jakob disease in a US surveillance study

BACKGROUND: Since 2004, several reported transfusion transmissions of variant Creutzfeldt-Jakob disease (vCJD) in the United Kingdom have reawakened concerns about the possible risk of similar transmissions of nonvariant or classic forms of CJD.
STUDY DESIGN AND METHODS: Patients with a CJD diagnosis and a history of donating blood were reported to the study coordinator. Through review of blood distribution and hospital records, the recipients of blood components from these donors were identified. We then determined each recipient's vital status and, if deceased, the cause(s) of death identified by matching the recipient's personal identifiers with the Centers for Disease Control and Prevention's National Death Index database. We conducted such searches after recipients were enrolled in this study and annually thereafter for those who remained alive.
RESULTS: The study included a total of 36 blood donors who subsequently developed CJD and 436 recipients. Through 2006, 91 of these recipients were still alive, 329 were deceased, and 16 were lost to follow-up. After transfusion, these three groups had survived a total of 2096.0 person-years. A total of 144 recipients survived 5 years or longer after transfusion and 68 of them had received blood donated 60 or fewer months before the onset of CJD in the donor. We identified no recipient with CJD.
CONCLUSIONS: The current results of this large, ongoing lookback study show no evidence of transfusion transmission of CJD. They reinforce the conclusion that the risk, if any, of transfusion transmission of prion disease by CJD donors is significantly lower than the comparable risk of such transmission by vCJD donors.     

Evaluation of algorithms for the diagnostic assessment and the reentry of blood donors who tested reactive for antibodies against hepatitis B core antigen

BACKGROUND: Screening of blood donations for antibodies against hepatitis B core antigen (anti‐HBc) is an accepted method to prevent some transfusion‐transmitted hepatitis B virus (HBV) infections. However, anti‐HBc testing may result in donor loss due to unspecific results in the currently available anti‐HBc tests. Algorithms to distinguish true‐positive from false‐positive results and for reentry of those donors who tested false anti‐HBc positive were evaluated retrospectively. STUDY DESIGN AND METHODS: Samples that tested reactive for anti‐HBc by chemiluminescent microparticle immunoassay (CMIA) were investigated for anti‐HBc by microparticle immunoassay, for anti‐HBs and hepatitis B surface antigen (HBsAg) by CMIA, and for HBV DNA by individual‐donor nucleic acid testing. Results were classified true positive, indeterminate, and false positive for anti‐HBc. Donors who tested indeterminate and false positive were admitted for reentry if follow‐up testing for anti‐HBc became negative and no further evidence for an HBV infection was apparent. RESULTS: A total of 554 of 148,000 samples, taken from 30,000 individuals within 3 years tested reactive for anti‐HBc by CMIA. Of those, 553 could be further classified: 142 (26%) true positive, 76 (14%) indeterminate, and 335 (60%) false positive. A total of 214 of 411 (52%) samples termed indeterminate or false positive were admitted for reentry and able to provide further donations. In one donor, anti‐HBc–positive/HBsAg‐ and HBV DNA–negative HBV DNA was detectable during follow‐up. CONCLUSION: According to our proposed algorithm, 26% of anti‐HBc–reactive results tested by CMIA were true positive. Many donors tested indeterminate or false positive can provide future donations if our proposed algorithm for reentry is applied. One donor at risk for transmitting HBV was identified solely by anti‐HBc testing.     

PL04Tissue Retrieval and Processing Initiatives to Reduce the Risk of vCJD Transmission

Risk reduction concerning potential tissue allograft vCJD transmission starts with effective donor selection and screening measures. Even as tests are developed and introduced, there are still risks regarding window period, which may result in potentially infective units being transplanted. Methodology can be implemented to reduce this risk by attempting to remove the infectious agents. NBS introduced blood leucodepletion as a risk reduction measure. For many highly processed tissue products, this is already achieved by washing blood and marrow from the graft. However the bone graft of preference for UK orthopaedic surgeons is fresh frozen femoral heads (containing blood/marrow) which have not been irradiated to 25 kGy. NBS have developed a bone washing protocol to achieve >99% marrow and blood depletion and are assessing whether the irradiation dose can be reduced as a result of bioreduction events included in the process. This is achieved without pooling tissues from multiple donors in turn reducing recipient exposure. Clinicians may find this a suitable alternative risk-reduced product. Other initiatives have been introduced to reduce the risk of abnormal PrP contamination of equipment, in turn cascading to subsequent grafts. Disposable equipment is now used wherever possible. Where not possible (e.g. bone saws, skin dermatomes etc.) the equipment is washed and sterilized to best practice (HTM2010 and HTM2030), is fully traced through subsequent graft exposures, and when a suitable screen test is performed, kit is quarantined until a negative result is received.     

Removal of exogenous (spiked) and endogenous prion infectivity from red cells with a new prototype of leukoreduction filter

BACKGROUND: Two recent probable cases of transmission of a variant of human Creutzfeldt-Jakob disease (vCJD) through blood transfusion suggest that the disease can be transmitted through transfusion of blood components from presymptomatic blood donors. In the absence of a preclinical screening test, removal of the infectious agent by processing is the only means by which risk to recipients of blood from donors with inapparent vCJD infections can be eliminated. STUDY DESIGN AND METHODS: In the endogenous infectivity study, a pool of 500 mL of whole blood was collected into CP2D anticoagulant from 263K-strain scrapie-infected hamsters, processed into 300 mL of red cells (RBCs), and then passed through a prion removal filter. Pre- and postfiltration samples were tested for PrP(sc) by Western blot and for infectivity by inoculation of healthy hamsters. In the exogenous (spiking) infectivity study, 30 mL of 10 percent (wt/vol) scrapie-infected brain homogenates was added to 270 mL of human RBCs and then filtered. Levels of PrP(sc) and infectivity were determined by Western blot and bioassay. RESULTS: In the endogenous infectivity study, the prefiltered RBCs transmitted disease to 6 of 43 animals, whereas the postfiltered RBCs did not transmit disease to any of 35 animals, and a barely visible prefiltration PrP(sc) Western blot signal was reduced below the level of detection in the postfiltration sample. In the exogenous (spike) study, infectivity was reduced by 3.7 log LD50 per mL, from 9.2 to 5.5 log LD50 per mL. CONCLUSION: The new filter was effective in removing both infectivity and PrP(sc) from RBCs. The use of this type of filter should reduce the risk of vCJD transmission through blood transfusion.     

The expression of prion protein (PrPC) in the megakaryocyte lineage

BACKGROUND: Cellular prion protein (PrP(C)) is a naturally occurring protein in normal individuals which adopts an abnormal conformation, termed scrapie prion protein (PrP(Sc)) that is associated with disease. There is great concern that clinically asymptomatic variant Creutzfeldt-Jacob disease (vCJD) may transmit PrP(Sc) in blood transfusion products. PrP(C) is widely expressed and has been found in human blood. The majority of cellular borne PrP(C) is associated with platelets (84%). Although PrP(C) mRNA has been demonstrated in platelets, the quantity is unknown and may not reflect the total PrP(C) present. OBJECTIVE: To investigate the expression of PrP(C) in the megakaryocyte lineage. METHODS: The expression of PrP(C) was studied in CD34+ cells, cultured megakaryocytes and platelets using electron microscopy, flow cytometry, semi-quantitative RT-PCR and immunofluorescence confocal microscopy. RESULTS AND CONCLUSIONS: The expression of PrP(C) appeared to increase with differentiation and polyploidization in the megakaryocyte lineage. PrP(C) was located within platelet alpha-granules and its source is likely to be from megakaryocyte precursors. If PrP(Sc) has a similar distribution, these results have implications for the selection of blood donors and preparation of cell-depleted blood products.     

The application of multiparameter reference intervals for pre-donation capillary blood counts: the experience of a single institution

Objectives: To evaluate a set of reference counts applied to multiparameter pre‐counts in blood donors. Aim: Analyse the impact of pre‐donation counts and specific reference intervals on donors' management. Background: Multiparameter blood counts allow an improved enrolment process of blood donors due to a prompt identification of abnormalities involving haemoglobin (Hb), white blood cells (WBC) and platelets (PLT). Methods/Materials: Multiple pre‐donation capillary counts were applied in the enrolment process of 13 347 consecutive donors. The rate of specific alterations of permanent exclusion and donor readmittance to donations for temporary exclusion had been evaluated, applying a set of multiparameter reference intervals. Results: Alterations involved Hb in 72·55% of cases, mean corpuscular volume (MCV) in 20·99%, total WBC in 9·39%, lymphocytes in 7·55% and PLT in 6·07%. Among donors with initial alterations (543; 4·06%), 12·70% were readmitted to donations within 15 days, 14·36% had permanent exclusion, 36·83% underwent prompt supplementation treatment and 36·09% were lost at follow‐up or refused treatments. Discussion: The systematic use of blood count reference intervals and pre‐donation multiparameter blood counts allowed prompt identification of WBC, PLT and MCV alterations, readmittance within 15 days of 12·70% of initially excluded donors and contributed to prompt management of supplement deficiency.     

Understanding the sex disparity in living kidney donation

Living donors are the preferred source of organs for kidney transplantation, which is the treatment modality of choice for end‐stage kidney disease. Health care systems widely promote living kidney donation. However, women are consistently overrepresented among living donors. The reasons behind the sex‐based disparity in living kidney donation remain poorly understood. Compared to women, men possess a greater amount of kidney function, and the higher deceased donation rate among men reflects their higher overall kidney quality. A plausible medical explanation for the sex‐based disparity in living kidney donation includes an uncompromising emphasis on preserving donor health, with less emphasis placed on organ quality, which is the main criterion in deceased donor selection. On the other hand, consent to deceased donation is also greater in women, indicating their greater desire to donate even though fewer women actually become deceased donors. Therefore, nonmedical reasons for the sex disparity in living donation must be sought. Increased empathic distress or emotional memory; a greater sense of responsibility, urgency, and impulsiveness with increased reaction to empathy; a different body image; and a different social status may all contribute to greater living kidney donation in women. Economic inequity may be the singular explanation when personal worth links to economic worth. To better understand the sex disparity in living kidney donation, we need better data on the reasons behind both nondonation and donor rejection after evaluation in clinical practice. Nondirected living kidney donation provides unique opportunities to minimize factors such as emotional distress, empathy, and impulsiveness. More liberal acceptance criteria for donors with isolated medical abnormalities and testing legitimate donor reimbursement strategies based on actual income levels rather than a fixed amount can assist in both ascertaining the reasons behind the sex disparity in living kidney donation and increasing overall living kidney donation rates.     

P54Production and Characterisation of Monoclonal Antibodies Against Human Platelet Prion Protein

To date all of the existing monoclonal antibodies which react with human prion protein have been produced following immunisation with recombinant PrP, PrP from other species or synthetic peptide fragments. The aim of this project was to produce monoclonal antibodies raised against the native form of PrP^c purified from human platelets. Following immunization of PrP^-/- Edinburgh mice and the use of conventional hybridoma techniques a panel of 12 monoclonal antibodies has been established. These antibodies have been characterized by epitope mapping; binding to both native/denatured platelet PrP and native/denatured α-helical/β-sheet recombinant mouse PrP; immunoprecipitation of PrP^c, PrP^sc and PrP^res from neurological control/vCJD brain homogenates and as probes for Western blotting, immunohistochemistry and flow-cytometry studies. A range of epitopes was recognised by the panel, with discrimination between normal α-helical and abnormal β-sheet forms. Several of the antibodies specifically captured abnormal forms of prion protein (PrP^sc and PrP^res ) found in vCJD-infected CNS and lymphoreticular tissues. It is hoped that these antibodies will aid in the early diagnosis and classification of human prion disease and the detection of vCJD infectivity in tissues for transplant and blood donations.     

Performance of an algorithm for the reentry of volunteer blood donors deferred due to false-positive test results for antibody to hepatitis B core antigen

BACKGROUND: Blood donor testing for antibody to hepatitis B core antigen (anti‐HBc) has been used in the United States for more than 20 years as a surrogate to prevent transmission by transfusion of non‐A,non‐B hepatitis, as a human immunodeficiency virus surrogate, and to reduce transmission of hepatitis B virus (HBV). Nonspecific anti‐HBc assays have caused deferral of hundreds of thousands of otherwise qualified donors. A more specific anti‐HBc test and a sensitive HBV DNA test should permit donor reentry after false‐positive anti‐HBc. STUDY DESIGN AND METHODS: A total of 1324 otherwise eligible volunteer donors, deferred for anti‐HBc reactivity on more than one occasion, were recruited from four collection facilities. They were tested using a licensed, more specific anti‐HBc test, a licensed hepatitis B surface antigen (HBsAg) test, and a licensed HBV DNA assay with a 95 percent limit of detection of not more than 10 copies per mL. RESULTS: From 11 to 32 percent of donors contacted by participating sites entered the study. Overall, 488 (37%) of the donors were negative on the more specific anti‐HBc test. The proportion of putative false‐positive samples varied according to the test responsible for the original deferral. A single donor, negative for the presence of anti‐HBc and HBsAg, was positive for the presence of HBV DNA in one of three replicates. Repeat testing of this donor 10 months later was negative for the presence of all markers of HBV infection, and the donor had a history of HBV vaccination with documented postimmunization anti‐HBs seroconversion 10 years before her anti‐HBc deferral, and was considered HBV DNA false positive. CONCLUSION: These data support reentry of donors with false‐positive anti‐HBc results on the relatively nonspecific assays that have been in use in the United States for more than 20 years.     

Feasibility study of a screening assay that identifies the abnormal prion protein PrPTSE in plasma: initial results with 20,000 samples

BACKGROUND: It is likely that transmission of variant Creutzfeldt‐Jakob disease (vCJD) occurs by transfusion and that the candidate infectious agent (PrP^TSE) is present in small concentrations in the blood of infected donors in the asymptomatic phase of the disease. A new blood screening assay has been developed to detect PrP^TSE in citrated plasma samples. STUDY DESIGN AND METHODS: Three regional Blood Transfusion Establishments (ETS) in France (ETS Alsace, ETS Bourgogne Franche‐Comté, and ETS Pyrénées‐Méditerranée) will screen 60,000 plasma samples (20,000 in each ETS) over a time period of approximately 9 to 12 months. RESULTS: Results provided in this report are those of the first testing site in Strasbourg, Alsace. The preliminary results have demonstrated an initial specificity of 97.60%. Upon repeat testing the specificity rate achieved 99.90% (20 repeat‐positive samples). Based on the known epidemiology of vCJD in France, it is likely that the repeat‐reactive samples are not true‐positives. CONCLUSION: The screening assay was studied in terms of specificity and practicality and was found to be suitable for use in routine testing of blood donations. However, throughput must be enhanced by automation of the assay, and traceability would be improved if automated systems were used to distribute and identify samples.     

Epidemiologic and laboratory findings from 3 years of testing United States blood donors for Trypanosoma cruzi

BACKGROUND: At most blood centers in the United States routine testing of donations for Trypanosoma cruzi using an enzyme‐linked immunosorbent assay (ELISA) is followed by supplemental testing by radioimmunoprecipitation assay (RIPA). The objective of this study was to report the results of routine testing and risk factor data from allogeneic blood donors. STUDY DESIGN AND METHODS: T. cruzi testing data from January 2007 through December 2009 were analyzed, and risk factor interviews and follow‐up studies were conducted on seroreactive donors. Prevalences of confirmed infection and risk factors associated with infection were assessed using logistic and multivariable logistic regression. RESULTS: Of 2,940,491 allogeneic donations from 1,183,076 donors, 305 (0.01% per donation tested and 0.026% per blood donor) were repeat reactive (RR) and 89 of those were confirmed positive by RIPA, yielding an overall seroprevalence of 1 per 33,039 donations and 1 per 13,292 donors. Country of birth and US blood center location differences in the seroprevalence of T. cruzi were evident. The odds of confirmed infection were highest if the donor reported having been bitten by the reduviid (kissing) bug (odds ratio [OR], 76.1; 95% confidence interval [CI], 11.1‐3173) followed by having lived in a rural area of Latin America (OR, 38.6; 95% CI, 15.1‐102.5). In multivariable analyses, having spent 3 months or more in Mexico or Central and/or South America was associated with the highest odds of RIPA‐confirmed infection (OR, 8.5; 95% CI, 2.7‐26.5). Polymerase chain reaction (PCR) testing of ELISA RR donors exhibited low sensitivity (1/22 [4%] RIPA‐confirmed donors was PCR positive). CONCLUSION: Risk factors for confirmed infection in US blood donors are consistent with the known epidemiology of Chagas disease. Blood donors or transfusions do not substantially contribute to the burden of T. cruzi infection in the United States.     

Diagnosis of transfusion-associated graft-vs.-host disease: the importance of short tandem repeat analysis

Transfusion-associated graft-vs.-host disease (TA-GvHD) can occur following transfusion of blood products containing immunocompetent lymphocytes, usually from HLA homozygous donors, into immunocompromised patients sharing one HLA haplotype with the donor. The diagnosis of TA-GvHD may be delayed due to the initial nonspecific clinical features involved. Investigations to detect the presence of donor-derived cells in the blood and/or affected tissues of the recipient are essential to confirm the diagnosis. We report the investigation of suspected TA-GvHD using short tandem repeat (STR) analysis, to detect the presence of donor cells (chimerism), in an immunocompetent patient admitted for coronary artery bypass surgery. Peripheral blood and skin biopsies (from affected and nonaffected sites) from the patient and peripheral blood samples from the implicated donors were taken for HLA typing and STR analysis. STR analysis revealed the presence of donor material in the patient's peripheral blood sample and in DNA extracted from the affected skin biopsy but not the unaffected biopsy, suggesting lymphocytes from this donor were responsible for the development of TA-GvHD. Furthermore, HLA typing results supported the diagnosis of TA-GvHD. These data demonstrate the use of STR and HLA analysis as effective tools in the diagnosis of TA-GvHD.     

Scotblood 2007: Tackling local and global issues in transfusion medicine - donor recruitment, effective use of blood, stem cell plasticity, and vCJD.

This commentary briefly highlights some of the local and the global contemporary issues affecting transfusion medicine worldwide. The main areas of focus addressed this year were: donor recruitment, stem cell plasticity, the effective use of blood, and vCJD.     

Impact of a transfusion-related acute lung injury reduction strategy on apheresis platelet collections

Background: Most blood centers in the US have implemented transfusion‐related acute lung injury (TRALI) mitigation strategies for apheresis platelet (AP) donations based on theoretical impact of donor loss. The aim of this study is to determine the actual impact of a TRALI mitigation strategy in a US blood center. Study Design and Methods: Daily collection events and resulting products were retrospectively obtained before and after implementation of a TRALI reduction strategy (HLA antibody testing female AP donors four or more pregnancies) for comparison. The retention rate of reassigned donors was determined by reviewing whole blood (WB) and/or apheresis red blood cell (AR) donations post reassignment. Data were obtained to compare donor frequency and split rate from reassigned (historical data) and new AP donors. Results: Mean daily collections (27.7 vs. 30.0) and total products (12,211 vs. 12,957) were significantly higher after implementation, but the number of products/collection event was lower (1.49 vs. 1.40). Mean collections/donor/year (4.0 vs. 1.8) and split rate (36% vs. 27%) were historically higher for reassigned (n = 45) versus new AP donors (n = 1,090). Seventy‐three of 112 donors (65%) testing positive for HLA antibodies returned for WB or AR donations, 31 of 45 (69%) active AP donors returned. Conclusions: Donor loss may not be adequate to estimate impact on AP inventory, as donation characteristics may differ between new donors and those reassigned. We show successful implementation of a TRALI mitigation strategy by increasing collection goals and AP donor recruitment efforts beyond donor loss. Retaining the majority of reassigned donors is feasible. J. Clin. Apheresis 2012. © 2012 Wiley Periodicals, Inc.