Introduction of a closed-system cell processor for red blood cell washing: postimplementation monitoring of safety and efficacy.

BACKGROUND: After introduction of a closed-system cell processor, the effect of this product change on safety, efficacy, and utilization of washed red blood cells (RBCs) was assessed. STUDY DESIGN AND METHODS: This study was a pre-/postimplementation observational study. Efficacy data were collected from sequentially transfused washed RBCs received as prophylactic therapy by ß-thalassemia patients during a 3-month period before and after implementation of the Haemonetics ACP 215 closed-system processor. Before implementation, an open system (TerumoBCT COBE 2991) was used to wash RBCs. The primary endpoint for efficacy was a change in hemoglobin (Hb) concentration corrected for the duration between transfusions. The primary endpoint for safety was the frequency of adverse transfusion reactions (ATRs) in all washed RBCs provided by Canadian Blood Services to the transfusion service for 12 months before and after implementation. RESULTS: Data were analyzed from more than 300 RBCs transfused to 31 recipients before implementation and 29 recipients after implementation. The number of units transfused per episode reduced significantly after implementation, from a mean of 3.5 units to a mean of 3.1 units (p < 0.005). The corrected change in Hb concentration was not significantly different before and after implementation. ATRs occurred in 0.15% of transfusions both before and after implementation. CONCLUSION: Safety and efficacy of washed RBCs were not affected after introduction of a closed-system cell processor. The ACP 215 allowed for an extended expiry time, improving inventory management and overall utilization of washed RBCs. Transfusion of fewer RBCs per episode reduced exposure of recipients to allogeneic blood products while maintaining efficacy.

Fatal false-negative transfusion infection involving a buffy coat platelet pool contaminated with biofilm-positive Staphylococcus epidermidis: a case report.

BACKGROUND: Bacterial contamination of platelet concentrates (PCs) poses the major posttransfusion infectious risk in developed countries. The aerobic microorganism most frequently isolated from PCs is coagulase-negative Staphylococcus epidermidis, a normal inhabitant of the human skin, which has been involved in fatal transfusion reactions worldwide. CASE REPORT: In September 2014, a splenectomized elderly male patient, suffering from leukemia, was transfused with two 5-day-old buffy coat platelet (PLT) pools. The patient returned to emergency on the same day with a low-grade fever. He was bacteremic and died on the next day. Microbiology and molecular testing of a blood sample from the patient and one of the PCs yielded the same S. epidermidis strain. Further analysis demonstrated that this S. epidermidis isolate displays a biofilm-positive phenotype in PCs. DISCUSSION: At Canadian Blood Services, PCs are screened for bacterial contamination with the BacT/ALERT system (bioMérieux) at approximately 24 hours postcollection. The implicated PC had been tested and yielded a false-negative culture result. A titration experiment indicated that, at the time of screening, the contaminated PC had a titer of less than 0.74 colony-forming units (CFU)/mL (<227 CFUs/unit) of S. epidermidis. Mathematical models have predicted that up to 70% of PCs contaminated with coagulase-negative staphylococci at concentrations of 0.02 CFU/mL can be missed by BacT/ALERT screening. CONCLUSION: Despite several mitigation strategies, false-negative cultures with current PLT screening practices still occur. This report creates awareness of the pathogenicity of opportunistic S. epidermidis, a low-virulence organism, in susceptible patients who may not develop a typical transfusion reaction.

Perioperative transfusion-related acute lung injury: the Canadian Blood Services experience.

PURPOSE: Transfusion-related acute lung injury (TRALI) is a devastating transfusion-associated adverse event. There is a paucity of data on the incidence and characteristics of TRALI cases that occur perioperatively. We classified suspected perioperative TRALI cases reported to Canadian Blood Services between 2001 and 2012, and compared them to non-perioperative cases to elucidate factors that may be associated with an increased risk of developing TRALI in the perioperative setting. METHODS: All suspected TRALI cases reported to Canadian Blood Services (CBS) since 2001 were reviewed by two experts or, from 2006 to 2012, the CBS TRALI Medical Review Group (TMRG). These cases were classified based on the Canadian Consensus Conference (CCC) definitions and detailed in a database. Two additional reviewers further categorized them as occurring within 72 h from the onset of surgery (perioperative) or not in that period (non-perioperative). Various demographic and characteristic variables of each case were collected and compared between groups. RESULTS: Between 2001 and 2012, a total of 469 suspected TRALI cases were reported to Canadian Blood Services; 303 were determined to be within the TRALI diagnosis spectrum. Of those, 112 (38%) were identified as occurring during the perioperative period. Patients who underwent cardiac surgery requiring cardiopulmonary bypass (25.0%), general surgery (18.0%) and orthopedics patients (12.5%) represented the three largest surgical groups. Perioperative TRALI cases comprised more men (53.6% vs. 41.4%, p=0.04) than non-perioperative patients. Perioperative TRALI patients more often required supplemental O2 (14.3% vs. 3.1%, p=0.0003), mechanical ventilation (18.8% vs. 3.1%), or were in the ICU (14.3% vs. 3.7%, p=0.0043) prior to the onset of TRALI compared to non-perioperative TRALI patients. The surgical patients were transfused on average more components than non-perioperative patients (6.0 [SD=8.3] vs. 3.6 [5.2] products per patient, p=0.0002). Perioperative TRALI patients were transfused more plasma (152 vs. 105, p=0.013) and cryoprecipitate (51 vs. 23, p<0.01) than non-perioperative TRALI patients. There was no difference between donor antibody test results between the groups. CONCLUSION: CBS data has provided insight into the nature of TRALI cases that occur perioperatively; this group represents a large proportion of TRALI cases.

Transfusion-related lung injury in children: a case series and review of the literature.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. The majority of the literature involves adult patients. The main objective of this study was to characterize the demographic features, clinical presentation, patient outcomes, and antibody profiles of TRALI patients reported to the Canadian Blood Service (CBS) and to assess similarities and differences between adult and pediatric TRALI cases. STUDY DESIGN AND METHODS: A retrospective review of cases of TRALI submitted to the CBS from 2001 to 2011 was performed. Information collected included recipient demographics, event details, blood component transfused, morbidity and mortality data, and donor antibody results. RESULTS: A total of 284 cases of definite, possible, or probable TRALI were reported. Six percent (n = 17) occurred in children. There were no significant differences between pediatric or adult patients with TRALI. Most of the children who presented with TRALI were either teenagers or less than 1 year of age. The incident rate of reported TRALI cases in Canada per 100,000 red blood cell transfusions was estimated at 5.58 for children and 3.75 for adults. CONCLUSIONS: This study is the largest case series of reported TRALI cases in children. Crude modeling suggests that the incidence of TRALI in children is similar to that of adults. Although the numbers are small, there do not appear to be differences in presentation or outcome between adults and children with TRALI. TRALI is associated with significant morbidity and mortality and pediatricians need to consider this diagnosis in children who experience respiratory distress after transfusions.

Blood donors implicated in transfusion-related acute lung injury with patient-specific HLA antibodies are more broadly sensitized to HLA antigens compared to other blood donors.

BACKGROUND: The prevalence of HLA antibodies in randomly surveyed blood donors was compared to the prevalence of antibody in donors who were associated with transfusion-related acute lung injury (TRALI) cases reported to Canadian Blood Services (CBS). STUDY DESIGN AND METHODS: Current operating procedure mandates that the CBS TRALI Medical Review Group (TMRG) refer possible TRALI cases to the (CBS) Platelet Immunology Laboratory for investigation. Donor samples from these TRALI cases were screened for HLA antibodies. In parallel, a survey was conducted to screen serum samples from blood donors who were not associated in TRALI cases. A comparison analysis of HLA antibody profiles in the two groups of donors was performed. RESULTS: We studied 121 TRALI-associated donors (TDs) who were recalled in a total of 44 cases reported to CBS and classified by TMRG. We also studied 149 survey donors (SDs) who were deferred for donation for varied reasons and consented to participate in a survey for HLA antibody screening. Twenty-two percent of SDs and 50.4% of TDs tested positive for HLA antibodies. In addition, TDs who were implicated in TRALI demonstrated broader sensitization and higher level of quantitative HLA antibody compared to nonimplicated TDs and SDs. CONCLUSION: Patient-specific Class I and II HLA antibodies are directly related to the risk of TRALI. Moreover, it supports the concept that HLA antibody strength is directly related to the risk of TRALI when the HLA antibody is patient specific; however, no clear cutoff as defined by mean fluorescence intensity is evident.

Transfusion-related acute lung injury prevention measures and their impact at Canadian Blood Services.

BACKGROUND: Blood operators have taken measures to reduce transfusion-related acute lung injury (TRALI). We classified suspected TRALI cases reported to Canadian Blood Services from 2001 to 2009 and assessed the impact of TRALI reduction measures. STUDY DESIGN AND METHODS: Using Canadian Consensus Conference definitions, cases were reviewed by two experts or, from 2006 to 2009, a TRALI Medical Review Group (TMRG). Detection of HLA antibodies was performed using the Luminex system starting in 2008. Measures implemented from 2007 to 2009 included use of predominantly male plasma, suspension of buffy coat platelets in male plasma, and deferral of females with a pregnancy history from plateletpheresis. The buffy coat production method was implemented from 2005 to 2008. RESULTS: Reporting of all suspected TRALI cases, as well as cases classified as definite or possible, increased from 2001 to 2004, was stable from 2004 to 2007, and declined in 2008 to 2009. The decline was most marked for plasma-associated cases, but occurred for all components. TMRG consensus on classification was achieved in 56% of cases. Cases identified as definitive or possible TRALI were significantly more likely to have donor antibody against a corresponding recipient antigen, compared to other cases. CONCLUSION: Hemovigilance data demonstrated an initial increase in TRALI cases, likely due to increased adverse event reporting and awareness of TRALI, followed by a decrease in cases related to all components. TRALI prevention measures and possibly the switch to the buffy coat production method may have contributed to the decline. Classification of cases remains challenging.

Mass-scale high-throughput multiplex polymerase chain reaction for human platelet antigen single-nucleotide polymorphisms screening of apheresis platelet donors.

BACKGROUND: Treatment with human platelet antigen (HPA)-matched platelets (PLTs) is the optimal therapy for bleeding secondary to neonatal alloimmune thrombocytopenia. Recent advances in high-throughput DNA-based blood group and PLT antigen genotyping have made it possible to screen plateletpheresis donors for potential HPA-matched PLT transfusion. STUDY DESIGN AND METHODS: This prospective study evaluated genomic DNA from plateletpheresis donors for single-nucleotide polymorphisms (SNPs) associated with HPA-1, -2, -3, -4, -5, and -15 to determine whether high-throughput multiplex genomic DNA PCR and oligonucleotide extension technology can be used for mass-scale PLT antigen genotyping. Genotyping using SNP technology was confirmed using sequence-specific polymerase chain reaction (SSP-PCR). RESULTS: Of the 748 donors screened, 277 were found to be negative for antigens implicated in alloimmune thrombocytopenia. In addition, two donors were homozygous for HPA-1b/b and -2b/b, six donors for HPA-1b/b and -3b/b, one for HPA-2b/b and -3b/b, one for HPA-1b/b and -5b/b, 10 for HPA-1b/b and -15 b/b, four for HPA-5b/b and -15b/b, and one for HPA-2b/b and -15b/b. Retesting using SSP-PCR was conducted for 60 donors. Discrepant results occurred between SNP and SSP-PCR in less than 20% of samples for HPA-1b/1b/HPA-3b/3b, HPA-5b/5b, and HPA-15b/b. DISCUSSION: High-throughput multiplex PCR SNP and confirmatory molecular genotyping are useful for mass-scale screening of apheresis PLT donors to provide antigen-negative genotypes. Refinements to mass-scale multiplex analysis technology would reduce further the confirmatory testing needed.

A rabbit model for monitoring in vivo viability of human platelet concentrates using flow cytometry.

BACKGROUND: Viability in vivo of novel platelet components cannot be readily determined in human transfusions. Elaboration of valid animal models may be useful for this purpose. STUDY DESIGN AND METHODS: Viability of platelet concentrates (PCs) WBC reduced before storage was determined by flow cytometry in rabbits whose reticuloendothelial system was inhibited by ethyl palmitate administration. PCs stored at 22 degrees C for 2 and 5 days (D2- and D5-PCs) or refrigerated PCs (3-6 days at 22 degrees C plus 1-4 days at 4 degrees C, RF-PCs) were transfused into rabbits. Five parameters of PC viability in vivo were calculated from human platelet survival curves: survival time, recovery 0.5 and 24 hours after transfusion (R0.5, R24), maximal recovery (Rmax), and total recovery for 0 to 24 hours (RSigma). RESULTS: No differences in viability of D2- and D5-PCs were found. In contrast, viability of RF-PCs was significantly lower than that of D2-PCs, as was revealed with diverse sensitivity by four parameters: RSigma > R24 > R0.5=survival time (p < 0.001, p < 0.01, and p < 0.05, respectively). CONCLUSION: The rabbit model elaborated is sufficiently sensitive to reveal differences in human platelet viability in vivo between conventional and cold-damaged PCs. It may be useful for comparing viability of different platelet components that cannot be readily tested in human transfusions.