giovedì 5 maggio 2016

Barcode error leading to sample misidentification during blood grouping

Possible causes for barcode label error. The fishbone diagram indicates four major categories of causes resulting in a barcode label error. Three examples for such causes are listed per category. The root cause for the error shown in Video Clip S1 was a hardware problem with the printer resolution (read more)

sabato 30 aprile 2016

Dried plasma: state of the science and recent developments

The early transfusion of plasma is important to ensure optimal survival of patients with traumatic hemorrhage. In military and remote or austere civilian settings, it may be impossible to move patients to hospital facilities within the first few hours of injury. A dried plasma product with reduced logistical requirements is needed to enable plasma transfusion where medically needed, instead of only where freezers and other equipment are available. First developed in the 1930s, pooled lyophilized plasma was widely used by British and American forces in WWII and the Korean War. Historical dried plasma products solved the logistical problem but were abandoned because of disease transmission. Modern methods to improve blood safety have made it possible to produce safe and effective dried plasma. Dried plasma products are available in France, Germany, South Africa, and a limited number of other countries. However, no product is available in the US. Promising products are in development that employ different methods of drying, pathogen reduction, pooling, packaging, and other approaches. Although challenges exist, the in vitro and in vivo data suggest that these products have great potential to be safe and effective. The history, state of the science, and recent developments in dried plasma are reviewed (read more)

lunedì 29 febbraio 2016

Transfusion of irradiated red blood cell units with a potassium adsorption filter: A randomized controlled trial



BACKGROUND : The irradiation of red blood cells (RBCs) causes damage of the RBC membrane with increased potassium (K) leak during storage compared with nonirradiated RBC units of similar age. A previous in vitro study showed a mean reduction of K of 94 ± 5% with a potassium adsorption filter (PAF).
STUDY DESIGN AND METHODS : A prospective, single-center, nonblinded, randomized controlled trial (RCT) was designed to evaluate the safety and efficacy of transfusing irradiated RBC units with the PAF. Patients 18 years of age or older who received irradiated RBC units due to chemotherapy-induced anemia were randomly assigned to receive irradiated RBC units with the PAF (PAF group) or with the standard blood infusion set (control group). Primary outcome measures were safety and efficacy of the PAF (absolute change in hemoglobin [Hb] and K, respectively, in patient's blood values after transfusing the irradiated RBC units with or without the PAF).
RESULTS : A total of 63 irradiated RBC units were transfused to 17 patients in the control group, and a total of 56 irradiated RBC units were transfused to 13 patients in the PAF group. The absolute change of Hb (9.3 ± 6.3 g/L vs. 8.1 ± 5.8 g/L; p = 0.3) and the absolute change of K (−0.01 ± 0.4 mmol/L vs. −0.01 ± 0.3 mmol/L; p = 0.2) were comparable between the two groups of the trial.
CONCLUSION : The transfusion of 1 irradiated RBC unit with the PAF was as safe and efficacious as the transfusion of 1 irradiated RBC unit with the standard blood infusion set in patients with chemotherapy-induced anemia (read more)

martedì 16 febbraio 2016

Caplacizumab for Acquired Thrombotic Thrombocytopenic Purpura

BACKGROUND : Acquired thrombotic thrombocytopenic purpura (TTP) is caused by aggregation of platelets on ultralarge von Willebrand factor multimers. This microvascular thrombosis causes multiorgan ischemia with potentially life-threatening complications. Daily plasma exchange and immunosuppressive therapies induce remission, but mortality and morbidity due to microthrombosis remain high.
METHODS : Caplacizumab, an anti–von Willebrand factor humanized single-variable-domain immunoglobulin (Nanobody), inhibits the interaction between ultralarge von Willebrand factor multimers and platelets. In this phase 2, controlled study, we randomly assigned patients with acquired TTP to subcutaneous caplacizumab (10 mg daily) or placebo during plasma exchange and for 30 days afterward. The primary end point was the time to a response, defined as confirmed normalization of the platelet count. Major secondary end points included exacerbations and relapses.
RESULTS : Seventy-five patients underwent randomization (36 were assigned to receive caplacizumab, and 39 to receive placebo). The time to a response was significantly reduced with caplacizumab as compared with placebo (39% reduction in median time, P=0.005). Three patients in the caplacizumab group had an exacerbation, as compared with 11 patients in the placebo group. Eight patients in the caplacizumab group had a relapse in the first month after stopping the study drug, of whom 7 had ADAMTS13 activity that remained below 10%, suggesting unresolved autoimmune activity. Bleeding-related adverse events, most of which were mild to moderate in severity, were more common with caplacizumab than with placebo (54% of patients vs. 38%). The frequencies of other adverse events were similar in the two groups. Two patients in the placebo group died, as compared with none in the caplacizumab group.
CONCLUSIONS : Caplacizumab induced a faster resolution of the acute TTP episode than did placebo. The platelet-protective effect of caplacizumab was maintained during the treatment period. Caplacizumab was associated with an increased tendency toward bleeding, as compared with placebo (read more)

mercoledì 3 febbraio 2016

Predicted effect of selectively testing female donors for HLA antibodies to mitigate transfusion-related acute lung injury risk from apheresis platelets

BACKGROUND : The use of male-donor-predominant plasma has reduced the risk of transfusion-related acute lung injury (TRALI), but the possible benefit of different mitigation strategies for other components is unknown. We evaluated the risk of TRALI from apheresis platelets (PLTs) to predict the effect of selectively testing female plateletpheresis donors who have been pregnant for HLA antibodies.
STUDY DESIGN AND METHODS : The American Red Cross hemovigilance program classified TRALI cases from apheresis PLTs or red blood cells (RBCs) in 2006 to 2013 or from predominantly male-donor (>95%) plasma in 2008 to 2013 and compared the component-specific TRALI rates.
RESULTS : The overall rate of TRALI was significantly higher for apheresis PLTs (6.2 cases per 106 units; OR [95% CI], 3.3 [2.3-4.8]) or plasma (3.8 cases per 106 units; OR [95% CI], 2.0 [1.4-2.9]) compared to RBCs (1.9 per 106 units). Twenty-nine of the 41 apheresis PLT cases involved female donors; 28 had been pregnant, and one had not been pregnant and was not tested. Twenty-five (61%) of the apheresis PLT TRALI cases had female donors with HLA Class I or Class II antibodies. In five of six cases that implicated specific HNA antibodies, the female parous donors also had multiple HLA antibodies.
CONCLUSIONS : TRALI was more likely after transfusion of apheresis PLTs than male-donor-predominant plasma or RBCs. A selective strategy to test all female plateletpheresis donors who have been pregnant for HLA antibodies might reduce the risk of TRALI by approximately 60% and prevent some cases from coexisting HNA antibodies (read more)

mercoledì 18 novembre 2015

Urinary di-(2-ethylhexyl) phthalate metabolites for detecting transfusion of autologous blood stored in plasticizer-free bags

BACKGROUND : Autologous blood transfusion (ABT) efficiently increases sport performance and is the most challenging doping method to detect. Current methods for detecting this practice center on the plasticizer di(2-ethlyhexyl) phthalate (DEHP), which enters the stored blood from blood bags. Quantification of this plasticizer and its metabolites in urine can detect the transfusion of autologous blood stored in these bags. However, DEHP-free blood bags are available on the market, including n-butyryl-tri-(n-hexyl)-citrate (BTHC) blood bags. Athletes may shift to using such bags to avoid the detection of urinary DEHP metabolites.
STUDY DESIGN AND METHODS : A clinical randomized double-blinded two-phase study was conducted of healthy male volunteers who underwent ABT using DEHP-containing or BTHC blood bags. All subjects received a saline injection for the control phase and a blood donation followed by ABT 36 days later. Kinetic excretion of five urinary DEHP metabolites was quantified with liquid chromatography coupled with tandem mass spectrometry.
RESULTS : Surprisingly, considerable levels of urinary DEHP metabolites were observed up to 1 day after blood transfusion with BTHC blood bags. The long-term metabolites mono-(2-ethyl-5-carboxypentyl) phthalate and mono-(2-carboxymethylhexyl) phthalate were the most sensitive biomarkers to detect ABT with BTHC blood bags. Levels of DEHP were high in BTHC bags (6.6%), the tubing in the transfusion kit (25.2%), and the white blood cell filter (22.3%).
CONCLUSIONS : The BTHC bag contained DEHP, despite being labeled DEHP-free. Urinary DEHP metabolite measurement is a cost-effective way to detect ABT in the antidoping field even when BTHC bags are used for blood storage (read more).

venerdì 30 ottobre 2015

Efficacy of transfusion with granulocytes from G-CSF/dexamethasone–treated donors in neutropenic patients with infection

High-dose granulocyte transfusion therapy has been available for 20 years, yet its clinical efficacy has never been conclusively demonstrated. We report here the results of RING (Resolving Infection in Neutropenia with Granulocytes), a multicenter randomized controlled trial designed to address this question. Eligible subjects were those with neutropenia (absolute neutrophil count <500/μL) and proven/probable/presumed infection. Subjects were randomized to receive either (1) standard antimicrobial therapy or (2) standard antimicrobial therapy plus daily granulocyte transfusions from donors stimulated with granulocyte colony-stimulating factor (G-CSF) and dexamethasone. The primary end point was a composite of survival plus microbial response, at 42 days after randomization. Microbial response was determined by a blinded adjudication panel. Fifty-six subjects were randomized to the granulocyte arm and 58 to the control arm. Transfused subjects received a median of 5 transfusions. Mean transfusion dose was 54.9 × 109 granulocytes. Overall success rates were 42% and 43% for the granulocyte and control groups, respectively (P > .99), and 49% and 41%, respectively, for subjects who received their assigned treatments (P = .64). Success rates for granulocyte and control arms did not differ within any infection type. In a post hoc analysis, subjects who received an average dose per transfusion of ≥0.6 × 109 granulocytes per kilogram tended to have better outcomes than those receiving a lower dose. In conclusion, there was no overall effect of granulocyte transfusion on the primary outcome, but because enrollment was half that planned, power to detect a true beneficial effect was low (read more)