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The article delves into the reconsideration of leukoreduction of whole blood for patients facing life-threatening hemorrhage, particularly in trauma centers and military blood programs. It examines the benefits and limitations of leukoreduction in reducing febrile reactions, CMV transmission, and HLA alloimmunization, as well as the operational challenges and benefits. The text also compares the use of leukoreduced (LR) and non-LR whole blood for transfusion purposes, highlighting cost implications, shelf life differences, and the need for further clinical trials to determine effects on patient outcomes. The article underscores the importance of carefully weighing the potential benefits and risks of using LR versus non-LR whole blood in clinical decision-making for patients with major bleeding. [Extracted from the article]

Background: Reported incidence of blood transfusion reactions (TR) varies greatly. Objective: To prospectively evaluate the incidence of acute TRs in dogs receiving allogenic blood products, using consensus definitions, and to assess factors associated with TRs. Animals: Dogs (n = 858) administered allogenic blood products (n = 1542) between March and November 2022. Methods: Prospective, multicenter surveillance study occurring in referral hospitals in the United States, United Kingdom, and Australia recording TRs in dogs administered blood products as defined by the consensus guidelines published by The Association of Veterinary Hematology and Transfusion Medicine in 2021. Results: The incidence of acute TR was 8.9% (95% CI 7.0‐11.1) for packed red blood cells (pRBCs) and 4.5% (95% CI 2.9‐6.6) for plasma products. The most frequently reported TRs were febrile nonhemolytic TRs (FNHTR; 4%, 95% CI 2.8‐5.5) when administering pRBCs and allergic TRs (3.2%, 95% CI 1.80‐5.10) when administering plasma products. A higher dose of pRBC (adjusted odds ratio [aOR] 1.04 [95% CI 1.00‐1.08]) was associated with a higher odds of TR. Administration of pRBCs stored for longer than 28 days was associated with higher odds of FNHTR (aOR 4.10 [95% CI 1.58‐10.65]) and acute hemolytic TR (AHTR; OR 15.2 [95% CI 3.35‐68.70]) when compared with pRBCs stored for 14 days or fewer. Leukoreduction of pRBC was not associated with lower odds of developing a TR (OR 1.47 [95% CI 0.89‐2.42]). Conclusions and Clinical Importance: Clinicians should be mindful of the age and dose of pRBC prescribed to dogs. [ABSTRACT FROM AUTHOR]

Abstract Background Reported incidence of blood transfusion reactions (TR) varies greatly. Objective To prospectively evaluate the incidence of acute TRs in dogs receiving allogenic blood products, using consensus definitions, and to assess factors associated with TRs. Animals Dogs (n = 858) administered allogenic blood products (n = 1542) between March and November 2022. Methods Prospective, multicenter surveillance study occurring in referral hospitals in the United States, United Kingdom, and Australia recording TRs in dogs administered blood products as defined by the consensus guidelines published by The Association of Veterinary Hematology and Transfusion Medicine in 2021. Results The incidence of acute TR was 8.9% (95% CI 7.0‐11.1) for packed red blood cells (pRBCs) and 4.5% (95% CI 2.9‐6.6) for plasma products. The most frequently reported TRs were febrile nonhemolytic TRs (FNHTR; 4%, 95% CI 2.8‐5.5) when administering pRBCs and allergic TRs (3.2%, 95% CI 1.80‐5.10) when administering plasma products. A higher dose of pRBC (adjusted odds ratio [aOR] 1.04 [95% CI 1.00‐1.08]) was associated with a higher odds of TR. Administration of pRBCs stored for longer than 28 days was associated with higher odds of FNHTR (aOR 4.10 [95% CI 1.58‐10.65]) and acute hemolytic TR (AHTR; OR 15.2 [95% CI 3.35‐68.70]) when compared with pRBCs stored for 14 days or fewer. Leukoreduction of pRBC was not associated with lower odds of developing a TR (OR 1.47 [95% CI 0.89‐2.42]). Conclusions and Clinical Importance Clinicians should be mindful of the age and dose of pRBC prescribed to dogs.

Abstract Background Leukoreduction has been used to limit the risk of adverse events. The most commonly used methodology is filtration (pre- or post-storage). However, whether pre-storage filtration is better than post-storage filtration needs to be clearly defined, particularly for countries that still use post-storage filtration. This study aimed to synthesize the best available evidence on the effectiveness of pre-storage filters compared with post-storage filters for transfusion reactions, for the occurrence of infections, for the length of hospital stay, and for the death of patients undergoing leukoreduced transfusion. Methods We searched the MEDLINE (PubMed), CINAHL (EBSCO), PsycINFO (APA), Scopus (Elsevier), The Cochrane Library (J. Wiley), Web of Science Core Collection (Clarivate Analytics), Embase (Elsevier), and LILACS (VHL) databases and gray literature for eligible studies in August 2020 and updated the search in October 2023. The Joanna Briggs Institute critical assessment tools were applied to analyze the quality appraisal of the studies. GRADE was used to determine the certainty of the evidence. Results The meta-analysis showed that pre-storage filtration was a protective factor for the occurrence of febrile non-hemolytic transfusion reaction in red blood cells (RR 0.49, 95% CI 0.41–0.59) and platelet concentrate transfusions (RR 0.16, 95% CI 0.12–0.22). The same did not occur for post-surgical infection after platelet concentrate transfusions (RR 0.82, 95% CI 0.65–1.04). Only one study analyzed the length of hospital stay and showed no significant difference between patients who received leukoreduced transfusions according to the type of filter used. According to the GRADE criteria, the certainty of the evidence for febrile non-hemolytic transfusion reactions was low for red blood cells and very low for platelet concentrate due to the high risk of bias. Infection was a low risk due to imprecision. Conclusions The results of this review showed that the certainty of recommending the best type of filter (pre- or post-storage) for the benefit of the outcomes analyzed is still fragile; therefore, more robust evidence is needed. Systematic review registration PROSPERO CRD42020192202.

Background: Leukoreduction has been used to limit the risk of adverse events. The most commonly used methodology is filtration (pre- or post-storage). However, whether pre-storage filtration is better than post-storage filtration needs to be clearly defined, particularly for countries that still use post-storage filtration. This study aimed to synthesize the best available evidence on the effectiveness of pre-storage filters compared with post-storage filters for transfusion reactions, for the occurrence of infections, for the length of hospital stay, and for the death of patients undergoing leukoreduced transfusion. Methods: We searched the MEDLINE (PubMed), CINAHL (EBSCO), PsycINFO (APA), Scopus (Elsevier), The Cochrane Library (J. Wiley), Web of Science Core Collection (Clarivate Analytics), Embase (Elsevier), and LILACS (VHL) databases and gray literature for eligible studies in August 2020 and updated the search in October 2023. The Joanna Briggs Institute critical assessment tools were applied to analyze the quality appraisal of the studies. GRADE was used to determine the certainty of the evidence. Results: The meta-analysis showed that pre-storage filtration was a protective factor for the occurrence of febrile non-hemolytic transfusion reaction in red blood cells (RR 0.49, 95% CI 0.41–0.59) and platelet concentrate transfusions (RR 0.16, 95% CI 0.12–0.22). The same did not occur for post-surgical infection after platelet concentrate transfusions (RR 0.82, 95% CI 0.65–1.04). Only one study analyzed the length of hospital stay and showed no significant difference between patients who received leukoreduced transfusions according to the type of filter used. According to the GRADE criteria, the certainty of the evidence for febrile non-hemolytic transfusion reactions was low for red blood cells and very low for platelet concentrate due to the high risk of bias. Infection was a low risk due to imprecision. Conclusions: The results of this review showed that the certainty of recommending the best type of filter (pre- or post-storage) for the benefit of the outcomes analyzed is still fragile; therefore, more robust evidence is needed. Systematic review registration: PROSPERO CRD42020192202. [ABSTRACT FROM AUTHOR]

Abstract Background Understanding of the biochemical and morphological lesions associated with storage of equine blood is limited. Objective To demonstrate the temporal sequences of lipid and metabolic profiles of equine fresh and stored (up to 42 days) and leukoreduced packed red blood cells (LR‐pRBC) and non‐leukoreduced packed RBC (nLR‐pRBC). Animals Packed RBC units were obtained from 6 healthy blood donor horses enrolled in 2 blood banks. Methods Observational study. Whole blood was collected from each donor using transfusion bags with a LR filter. Leukoreduction pRBC and nLR‐pRBC units were obtained and stored at 4°C for up 42 days. Sterile weekly sampling was performed from each unit for analyses. Results Red blood cells and supernatants progressively accumulated lactate products while high‐energy phosphate compounds (adenosine triphosphate and 2,3‐Diphosphoglycerate) declined. Hypoxanthine, xanthine, and free fatty acids accumulated in stored RBC and supernatants. These lesions were exacerbated in non‐LR‐pRBC. Conclusion and Clinical Importance Leukoreduction has a beneficial effect on RBC energy and redox metabolism of equine pRBC and the onset and severity of the metabolic storage lesions RBC.

Transfusion reactions induced by platelet transfusions may be reduced and alleviated by leukocyte reduction of platelets. Although leukoreduction of apheresis platelets can be performed either pre-storage or post-storage, seldom studies directly compare the incidence of transfusion reaction in these two different blood products. We conducted a retrospective study to compare the transfusion reactions between pre-storage and post-storage leukoreduced apheresis platelets. We reviewed the general characteristics and the transfusion reactions, symptoms, and categories for inpatients who received pre-storage or post-storage leukoreduced apheresis platelets. Propensity-score matching was performed to adjust for baseline differences between groups. A total of 40,837 leukoreduction apheresis platelet orders were reviewed. 116 (0.53%) transfusion reactions were reported in 21,884 transfusions with pre-storage leukoreduction, and 174 (0.91%) reactions were reported in 18,953 transfusions with post-storage leukoreduction. Before propensity-score matching, the odds ratio for transfusion reactions in the pre-storage group relative to the post-storage group was 0.57 (95% confidence interval [CI] 0.45–0.72, P < 0.01); the odds ratio after matching was 0.63 (95% CI 0.49–0.80, P < 0.01). A two-proportion z-test revealed pre-storage leukoreduction significantly decreases the symptoms of chills, fever, itching, urticaria, dyspnea, and hypertension as compared with those in post-storage leukoreduction. Pre-storage leukoreduced apheresis platelet significantly decreased febrile non-hemolytic transfusion reaction as compared with post-storage groups. This study suggests pre-storage leukoreduction apheresis platelet significantly decreases the transfusion reaction as compared with those in post-storage leukoreduction. [ABSTRACT FROM AUTHOR]

Background: Understanding of the biochemical and morphological lesions associated with storage of equine blood is limited. Objective: To demonstrate the temporal sequences of lipid and metabolic profiles of equine fresh and stored (up to 42 days) and leukoreduced packed red blood cells (LR‐pRBC) and non‐leukoreduced packed RBC (nLR‐pRBC). Animals: Packed RBC units were obtained from 6 healthy blood donor horses enrolled in 2 blood banks. Methods: Observational study. Whole blood was collected from each donor using transfusion bags with a LR filter. Leukoreduction pRBC and nLR‐pRBC units were obtained and stored at 4°C for up 42 days. Sterile weekly sampling was performed from each unit for analyses. Results: Red blood cells and supernatants progressively accumulated lactate products while high‐energy phosphate compounds (adenosine triphosphate and 2,3‐Diphosphoglycerate) declined. Hypoxanthine, xanthine, and free fatty acids accumulated in stored RBC and supernatants. These lesions were exacerbated in non‐LR‐pRBC. Conclusion and Clinical Importance: Leukoreduction has a beneficial effect on RBC energy and redox metabolism of equine pRBC and the onset and severity of the metabolic storage lesions RBC. [ABSTRACT FROM AUTHOR]

Background: Red Blood cells (RBCs) bring about harmful consequences during storage. MicroRNA (miRNA) dysregulation in stored RBCs could represent potential biomarkers of storage lesions. Although leukoreduction prevents damage to RBCs, it is uncertain whether leukoreduction of RBCs would impact the dysregulation of miRNAs during storage. This study evaluated the potential role of miRNAs for any alteration of leukoreduced (LR) and non‐leukoreduced (NLR) RBCs till 21 days of storage. Study Design and Methods: In this prospective study, thirty male volunteers' blood was equally divided into leukoreduced RBCs (LR) and NLR RBC (NLR) bags and stored till Day 21 at 4‐60c. Selected miRNAs were quantified on Days 0 and 21. Further, bioinformatic tools were used to analyze the selected miRNAs and their predicted target genes (mRNAs) and identify the miRNA‐mRNA regulatory relationships. Results: A significantly higher fold change values of three miRNAs (miR‐96‐5p, miR‐197‐3p, miR‐769‐3p) were observed in NLR RBCs (p <.05). A significantly higher (p <.05) expression levels of miR‐150‐5p and miR‐197‐3p were observed in NLR RBCs till 21 days of storage. Further, the correlation with mRNA quantification confirmed the regulatory role of these miRNAs upon functional pathway enrichment analysis. Discussion: A higher level of dysregulation of miRNAs was observed in NLR RBCs. Validation from In‐Silico analysis suggested the regulatory role of miRNAs in cell apoptosis, senescence, and RBC‐related signaling pathways. This indicated that stored LR RBCs would likely have better in vivo survival and function following transfusion. However, an in vivo study of miRNA in RBCs is warranted for conclusive evidence. [ABSTRACT FROM AUTHOR]

BACKGROUND: Leukocytes are responsible for producing both immune and nonimmune adverse reactions, and therefore, various methods have been developed to remove them from the blood components before transfusion. AIM: The aim of this study was to analyze the quality parameters in leukoreduced red cell concentrates (RCCs) and investigate the efficiency of leukocyte removal and red cell recovery in the leukoreduction methods followed in our center. MATERIALS AND METHODS: The study evaluated the quality parameters in 112 RCCs prepared using buffy-coat reduction by the Terumo automatic component extractor II+ system, manual saline washing, and leukofiltration using the Leucolab filter system. RESULTS: With analysis, leukofiltration was found to be the most efficient in reducing leukocyte content in RCCs, achieving a mean leukoreduction of 99.99%. Buffy-coat reduction and saline washing achieved a leukoreduction of 78.54% and 82.67%, respectively. While filtration showed the least red cell recovery of 81.93% compared to 90.57% in buffy-coat reduction and 91.87% in saline washing methods. An analysis of hemoglobin content showed that none of the buffy-coat removed RCCs processed from 350-ml collections and underwent poststorage leukofiltration could meet the European Standards for minimum hemoglobin content. CONCLUSION: Filtration is found to be the better method for leukoreduction of RCCs. It is suggested to perform a single method of leukoreduction preferably leukofiltration for maximum red cell recovery. [ABSTRACT FROM AUTHOR]

In many fields of clinical medicine and blood transfusion, the human leukocyte antigen (HLA) system is crucial. Alloimmunization happens as a result of an immune response to foreign antigens encountered during blood transfusion. This gives rise to alloantibodies against red blood cells (RBCs), HLA, or human platelet antigen (HPA). HLA alloimmunization following allogeneic transfusion was shown to be a result of contaminating white blood cells (WBCs) present in the product. It is a common complication of transfusion therapy that leads to difficulties in clinical intolerance and refractoriness to platelet transfusion during patient management. Single-donor platelets, prophylactic HLA matching, leukoreduction, and irradiation of cellular blood products are some of the mechanisms to prevent HLA alloimmunization during a blood transfusion. Now, the best approach to reduce the occurrence of primary HLA alloimmunization is the removal of WBCs from the blood by filtration. [ABSTRACT FROM AUTHOR]

Recipient safety measures play a key role in overall transfusion efficacy. The key advances in safety over the first century of transfusion medicine have been the development of techniques to prevent hemolytic transfusion reactions, hemolytic disease of the newborn and transmission of viral pathogens. While these risks remain important, they affect many fewer patients than previously. We propose that some of the most important current safety issues relate to toxicities broadly encompassed by the immunomodulatory effects of allogeneic transfusion. These include (1) universal leukoreduction to mitigate nosocomial infections, inflammation and organ injury, (2) removal of stored supernatant and its attendant toxic contents that cause dysfunctional immunity and organ injury, (3) avoiding infusing ABO incompatible antigen and antibody that can lead to bleeding, platelet refractoriness and inflammation, (3) minimizing prophylactic transfusions (particularly of plasma and platelets) except where benefit is proven, and (4) avoiding use of normal saline which is linked to renal failure and possibly hemolysis. Accompanying these safety measures will be the continued growth of one of the most important safety measures, patient blood management, which has as one benefit the avoidance of unnecessary and harmful transfusions. Reducing the toxicity of transfusions will enhance the improved clinical outcomes seen with patient blood management. [ABSTRACT FROM AUTHOR]

Hypotensive transfusion reaction is a distinct category of adverse sequelae of transfusion characterized by an early and abrupt onset of hypotension, typically resolving promptly upon discontinuation of the transfusion. The primary mechanism behind this reaction seems to be the accumulation of bradykinin in the transfused blood product during processing. The authors wish to highlight a case of isolated hypotensive reaction following administration of leukoreduced platelets in an Indian male patient, which required vasopressors. Awareness of the risk factors and clinical presentation for this type of reaction are vital for proper patient care and the prevention of future incidents.

Background and Objectives: The aim of this study was to compare three platforms side-by-side: Nageotte hemocytometer, flow cytometry (FC), and standard hematology analyzer for enumeration of residual white blood cells (rWBCs) in single donor platelets (SDPs) apheresis. Materials and Methods: This was a prospective observational study conducted in a tertiary care oncology center by evaluating 36 units of SDP that were collected and tested in parallel by three different methods for the enumeration of rWBCs. All tests were performed within 24 h of collection according to the manufacturers' recommended methods. Counting by the Nageotte hemocytometer was done by: rWBC/μl = (cells counted × dilution/gridded area volume [50 μl]) and FC calculation was performed by: rWBC/μl = (total beads × total number of leukocyte events/total beads acquired × total sample volume). Results: The number of rWBCs detected by FC was between 1 white blood cell (WBC)/μl and 8 WBCs/μl; whereas, those detected by Nageotte chamber were between 3 WBC/μl and 6 WBCs/μl. The range of rWBC detected by hematology analyzer was 100 WBC/μl to 270 WBCs/μl. There was no correlation observed between the results obtained in standard hematology analyzer with any of the other two methods. The concordance correlation coefficient was measured by kappa analysis and found to be 0.71 between hemocytometry and FC. Linear regression analysis also showed a moderate correlation (R2 = 0.42) between the two methods. However, the coefficient of variation was found to be 49.32% in Nageotte method compared to the 17.55% in FC (P < 0.001). Conclusion: FC followed by Nageotte chamber counting is a better method compared to the standard hematology analyzer for the enumeration of rWBCs. To overcome the cost of FC it is high time to explore the scope and feasibility of a centralized quality monitoring system in India for all leukoreduced blood components.

Hypotensive transfusion reaction is a distinct category of adverse sequelae of transfusion characterized by an early and abrupt onset of hypotension, typically resolving promptly upon discontinuation of the transfusion. The primary mechanism behind this reaction seems to be the accumulation of bradykinin in the transfused blood product during processing. The authors wish to highlight a case of isolated hypotensive reaction following administration of leukoreduced platelets in an Indian male patient, which required vasopressors. Awareness of the risk factors and clinical presentation for this type of reaction are vital for proper patient care and the prevention of future incidents. [ABSTRACT FROM AUTHOR]

Human T-cell lymphotropic virus type 1 and 2 (HTLV-1/2) screening is not mandatory in Spanish blood banks. In Catalonia, selective screening was introduced in 2008, followed by universal screening in 2011. We present herein a 10-year experience of HTLV testing in blood donors. HTLV-1/2 selective screening was performed using Ortho-Clinical Diagnostics HTLV-I/HTLV-II Ab-Capture ELISA between February 2008 and May 2009, then Abbott Prism HTLV-I/ HTLV-II assay until December 2010. Abbott Architect rHTLV-I/II assay was then used for HTLV-1/2 universal screening in pooled samples. INNO-LIA HTLV I/II Score (Fujirebio) and in-house HTLV-1/2 proviral DNA real-time PCR were used in reactive samples. Follow-up was offered to confirm HTLV-1/2 donors in Vall d'Hebron Hospital. Between 2008 and 2017, 51 blood donors were confirmed HTLV positive (46 HTLV-1, 4 HTLV-2 and 1 HTLV) out of 2,114,891 blood donations (1 in 41,468). Sixty-nine percent were female, median age was 40 years and most were born in Latin America (69%), followed by Europe (25%), Africa (4%) and Asia (2%). Screening of relatives and partners identified 12 additional HTLV-1 cases. Lookback studies did not show any HTLV-1/2 transmission. HTLV infections found in blood donors mirror epidemiological changes in the population of Spain. Consequently, HTLV should be considered a potential risk for recipients and calls for the design of optimal strategies to ensure transfusion safety. [ABSTRACT FROM AUTHOR]

Objectives: To determine the effects of donor and red blood cells concentrate characteristics on recipient hemoglobin increment following red blood cells transfusion in pediatric patients. Methods: This cross-sectional study was conducted at The Hematology & Transfusion Medicine Department of The UCHS & The Children’s Hospital, Lahore from 23rd December 2020 to 31st July 2021 after Institutional Ethical committee approval. After taking informed consent from parents/guardians, One hundred recipients receiving RBCs unit transfusion studied along with the respective donors. The donor’s details were recorded on a pre-designed proforma which included age, gender, Body Mass Index (BMI), CBC analysis (Hemoglobin [Hb] & Hematocrit) and blood group. Components’ preparation, storage and modifications details were also recorded. Hb levels of recipient were determined 12 hours prior to transfusion and 12-18 hours after transfusion. The data was analyzed on SPSS version 26. Results: Among recipients, the mean age was 5.25 ±3 years and male to female ratio was 1.16:1. The mean pre-transfusion Hb level of patients was 6.48g/dl (SD: 2.15) and mean post transfusion Hb was 8.824 g/ dl (SD: 2.03) with a significant raise after transfusion (p< 0.001). Majority donors (60%) were between 18 to 30 years of age and mean age was 30.7 years (SD: 9.04). The hemoglobin increment was reduced for transfusion of RBC units from donor with greater age. Post- transfusion Hb rise was more in Rh D positive donations than Rh D negative (p< 0.0001). No significance of donors’ gender, BMI, Hb and hematocrit was found in relation to Hb increment. Among RBCs concentrate features, washing with normal saline found to have greater Hb increment, particularly in Thalassemia patients (p< 0.0001). Conclusion: Donors’ age and Rh blood group and red blood cell concentrates’ washing accounts for significant rise in recipient’s post-transfusion hemoglobin. These factors may be used to predict changes in recipients’ hemoglobin before transfusion. [ABSTRACT FROM AUTHOR]

Background and Objectives: The aim of this study was to compare three platforms side-by-side: Nageotte hemocytometer, flow cytometry (FC), and standard hematology analyzer for enumeration of residual white blood cells (rWBCs) in single donor platelets (SDPs) apheresis. Materials and Methods: This was a prospective observational study conducted in a tertiary care oncology center by evaluating 36 units of SDP that were collected and tested in parallel by three different methods for the enumeration of rWBCs. All tests were performed within 24 h of collection according to the manufacturers' recommended methods. Counting by the Nageotte hemocytometer was done by: rWBC/μl = (cells counted × dilution/gridded area volume [50 μl]) and FC calculation was performed by: rWBC/μl = (total beads × total number of leukocyte events/total beads acquired × total sample volume). Results: The number of rWBCs detected by FC was between 1 white blood cell (WBC)/μl and 8 WBCs/μl; whereas, those detected by Nageotte chamber were between 3 WBC/μl and 6 WBCs/μl. The range of rWBC detected by hematology analyzer was 100 WBC/μl to 270 WBCs/μl. There was no correlation observed between the results obtained in standard hematology analyzer with any of the other two methods. The concordance correlation coefficient was measured by kappa analysis and found to be 0.71 between hemocytometry and FC. Linear regression analysis also showed a moderate correlation (R2 = 0.42) between the two methods. However, the coefficient of variation was found to be 49.32% in Nageotte method compared to the 17.55% in FC (P < 0.001). Conclusion: FC followed by Nageotte chamber counting is a better method compared to the standard hematology analyzer for the enumeration of rWBCs. To overcome the cost of FC it is high time to explore the scope and feasibility of a centralized quality monitoring system in India for all leukoreduced blood components. [ABSTRACT FROM AUTHOR]

Acute myeloid leukaemia, Vinblastine, Hyperleukocytosis, Hydroxyurea, Leukapheresis, Leukoreduction Vinblastine's leukoreductive effect may be comparable to HU and leukapheresis; vinblastine showed similar early mortality rates (15.4%) to leukapheresis and HU, which range from 3.8 to 57.1% [[6]-[9]]. Keywords: Acute myeloid leukaemia; Vinblastine; Hyperleukocytosis; Leukoreduction; Hydroxyurea; Leukapheresis EN Acute myeloid leukaemia Vinblastine Hyperleukocytosis Leukoreduction Hydroxyurea Leukapheresis 487 489 3 02/02/23 20230201 NES 230201 Supplementary Information The online version contains supplementary material available at https://doi.org/10.1007/s00277-022-05048-7. Boxplots showing WBCs and percentage of blasts two days after vinblastine administration in all patients (A and B) and in patients with hyperleukocytosis (C, D). [Extracted from the article]

Abstract Background Leukoreduction is a routine procedure in human transfusion medicine but is uncommon in veterinary. Objectives To evaluate the effect of leukoreduction on the quality of canine whole blood (WB) and blood products during storage. Animals Ten canine blood donors. Methods This is a case series study. An amount of 450 mL of blood was collected from each dog. Five WB and 5 packed red blood cells (pRBC) bags were divided into 2 units each: leukoreduced (LR) and non‐leukoreduced (nLR). RBC count, erythrocytes' mean osmotic fragility (MOF), 2,3‐diphosphoglycerate (2,3‐DPG), adenosine triphosphate (ATP), percentage of hemolysis, potassium (K), lactate, glucose, and cytokines were measured weekly from day of donation (T0) to day 35 (T35); pH, coagulation times, and clotting factors were evaluated at T0 and T35 from WB and in fresh frozen plasma after 1 year of storage. Results Leukoreduction showed positive effects on lactate (T35: LR WB 14.42 mmol/L SD 2.71, nLR WB 22.42 mmol/L SD 1.86, LR pRBC 20.88 mmol/L SD 2.65, nLR pRBC 36.81 mmol/L SD 2.34; P

Blood transfusion necessity in neurosurgery varies based on surgical type, blood loss, and patient anemia. Leukocytes in red blood cells (RBCs) component release pro-inflammatory cytokines during storage, contributing to transfusion-related immunomodulation (TRIM). Our aim was to examine the impact of the leukocyte content in transfused PRBCs on patients undergoing neurosurgery for meningioma tumours. This prospective randomized controlled trial conducted from 2018 to 2020 by dividing patients randomly into non-leukoreduced (NLR) (n = 65) and leuko-reduced (LR) (n = 65) groups based on PRBCs received during surgery and hospital stay. Hospital and ICU stays, mechanical ventilation duration, and postoperative bacterial infections were observed. Hematological parameters and cytokine levels (IL-10, INF-gamma, and FAS-L) were assessed at pre-transfusion, 24 h, and 7 days post-transfusion. Data analysis included Mann-Whitney U test, Friedman test, Fisher's chi-square test, with statistical significance at p < 0.05. In our study, ICU and hospital stay duration showed no significant difference (p = 0.06) between groups. However, NLR group had longer mean mechanical ventilation (18 ± 40.1 h) than the LR group (12.8 ± 8.6 h). Both groups showed statistically significant increase in Fas-L level on days 1 and 7 (p < 0.05). The IL-10 levels rose 43% in the NLR group, while and decreased by 7% the LR group on day 1. On day 7, IL-10 increased by 75% in NLR and decreased by 40% in LR, with no significance (p > 0.05). In conclusion, leukoreduction appeared to offer some immune response protection in term of reducing mechanical ventilation timings and cytokine level changes. [ABSTRACT FROM AUTHOR]

Recent studies identify large quantities of inflammatory cellular debris within Fresh Frozen Plasma (FFP). As FFP is a mainstay of hemorrhagic shock resuscitation, we used a porcine model of hemorrhagic shock and ischemia/reperfusion to investigate the inflammatory potential of plasma-derived cellular debris administered during resuscitation. The porcine model of hemorrhagic shock included laparotomy with 35 % hemorrhage (Hem), 45 min of ischemia from supraceliac aortic occlusion with subsequent clamp release (IR), followed by protocolized resuscitation for 6 h. Cellular debris (Debris) was added to the resuscitation phase in three groups. The four groups consisted of Hem + IR (n = 4), Hem + IR + Debris (n = 3), Hem + Debris (n = 3), and IR + Debris (n = 3). A battery of laboratory, physiologic, cytokine, and outcome data were compared between groups. As expected, the Hem + IR group showed severe time dependent decrements in organ function and physiologic parameters. All animals that included both IR and Debris (Hem + IR + Debris or IR + Debris) died prior to the six-hour end point, while all animals in the Hem + IR and Hem + Debris survived. Cytokines measured at 30–60 min after initiation of resuscitation revealed significant differences in IL-18 and IL-1β between all groups. Ischemia and reperfusion appear to prime the immune system to the deleterious effects of plasma-derived cellular debris. In the presence of ischemia and reperfusion, this model showed the equivalency of 100 % lethality when resuscitation included quantities of cellular debris at levels routinely administered to trauma patients during transfusion of FFP. A deeper understanding of the immunobiology of FFP-derived cellular debris is critical to optimize resuscitation for hemorrhagic shock. [ABSTRACT FROM AUTHOR]

Abstract We report five cases of malignant pertussis, a rare but life‐threatening illness. Current therapies include supportive care and leukoreduction. Notably, leukoreduction might be more effective when initiated prior to the development of organ failure and pulmonary hypertension.

Objective: Evaluate the association between leukoreduced red blood cell (RBC) storage length and hospital‐acquired infection (HAI) incidence rate in critically ill children. Background: RBC transfusions are common in critically ill children. Despite their benefits, observational studies suggest an association between them and HAIs. One possible mechanism for increased HAI is transfusion‐related immunomodulation due to bioactive substances' release as transfused blood ages. Methods: In this secondary analysis of the 'Transfusion Requirement in Paediatric Intensive Care Units' (TRIPICU) study, we analysed a subset of 257 participants that received only one pre‐storage leukoreduced RBC transfusion. RBC storage length was classified as 1) transfusion of 'fresh' RBCs (≤10 days), 2) transfusion of 'stored' RBCs (21–34 days), and 3) transfusion of 'long‐stored' RBCs (≥35 days). All were compared to a 'golden' period (11–20 days), representing the time between 'fresh' and 'stored'. We used quasi‐Poisson multivariable regression models to estimate the HAI incidence rate ratio (IRR) and corresponding 95% confidence interval (CI). Results: We found that the association between the length of storage time of leukoreduced RBCs and HAIs was not significant in the 'fresh' group (IRR 1.23; 95% CI 0.55, 2.78) and the 'stored' group (IRR 1.61; 95% CI 0.63, 4.13) when compared to the 'golden' period. However, we observed a statistically significant association between the 'long‐stored' group and an increase in the HAI incidence rate (IRR 3.66; 95% CI 1.22, 10.98). Conclusion: Transfusion of leukoreduced RBC units stored for ≥35 days is associated with increased HAI incidence rate in haemodynamically stable, critically ill children. [ABSTRACT FROM AUTHOR]

Abstract Background Neutrophil extracellular traps (NETs), webs of DNA and citrullinated histones extruded from activated neutrophils cause transfusion‐related acute lung injury. Supernatants of stored red blood cell (RBC) units might promote NETosis in neutrophils from the units or from transfusion recipients. Hypotheses (1) NETs form during storage of canine RBC, (2) leukoreduction (LR) before storage of RBC reduces NETosis, and (3) supernatant from stored, nonleukoreduced (NLR) RBC units induces NETosis in healthy canine neutrophils modeling transfusion recipients. Animals Six healthy purpose‐bred research dogs were utilized for blood donation. Methods Prospective controlled study. RBC units were collected from each dog, aseptically divided into 2 equal subunits, 1 of which was leukoreduced, and stored for 42 days. Stored units were sampled biweekly for quantification of NET markers citrullinated histone H3 (Western blot) and cell‐free DNA (cfDNA) (DNA dye binding). Unit supernatants were applied ex vivo to canine neutrophils and extracellular DNA release representing NETosis was assessed. Results Markers of NETs increased during RBC storage (cfDNA P

Abstract Background The ability of tick-borne agents to survive in stored blood bags is a key factor for their transmissibility by blood transfusion. The aim of this study was to evaluate the survival and potential infectivity of Rickettsia conorii (RC) in artificially contaminated canine whole blood (WB) and in leukoreduced whole blood (LR-WB) during the storage period. Methods RC was cultured on L929 cells. We used a one-week 25-cm2 flask with 70–80% of L929 infected cells to prepare the bacterial inoculum by pelleting cells and suspending the pellet in the donors’ serum. We infected five 100 ml WB units with RC within 2 h from the collection and maintained it at room temperature for 4 h prior to refrigeration. We filtered 50 ml of each WB bag to obtain leukoreduced WB (LR-WB) at day 1 post-infection (dpi). We checked WB and LR-WB bags at 1, 4, 7, 14, 21, 28, 35 dpi for RC presence and viability through real-time PCR (rPCR) for DNA and mRNA, respectively, and by isolation. Identification of isolates was confirmed by indirect immunofluorescence and rPCRs. Results RC survived for the entire storage period in both whole and leukoreduced blood. All bags contained viable bacteria until 7 dpi; RC viability generally decreased over time, particularly in LR-WB bags where the isolation time was longer than in WB. Viable bacteria were still isolated at 35 dpi in 3 WB and 3 LR-WB. Conclusions Leukoreduction reduced but did not eliminate RC in infected units. The survival and infectivity of RC in canine blood during the storage period may represent a threat for recipients.

Background: The temperature at which filtration takes place has been reported to influence the efficacy of leukoreduction. We aimed to compare the residual leukocyte count (RLC) in red cell units (RCUs) filtered at cold (CT) versus room temperature (RT) and to assess whether this correlates clinically with a difference in the incidence of acute transfusion reactions (ATRs). Methods and materials: In the first part of the study, whole blood units collected were randomly allocated for subsequent filtration at CT and RT, respectively. RLC postfiltration was assessed using flow cytometry. The second part of the study was a nonrandomized clinical trial in which incidence of ATR was compared between RCUs filtered at RT and CT for 6 months each. Results: Thirty‐five RCUs each underwent leukofiltration at CT and RT, respectively. The median RLCs in the filtered units at CT and RT were 0.02 × 106 and 0.1 × 106 leukocytes/unit, respectively (p =.0001), with no difference in red blood cell (RBC) recovery (p =.41). During the second part, 3455 RCUs filtered at RT and 3539 RCUs filtered at CT were transfused to patients. The rate of febrile non‐hemolytic transfusion reaction (FNHTR) among transfused patients was less with units filtered at CT (1 per 2000 transfusions) in comparison to RT (1 per 588 transfusions). The difference was, however, not significant (p =.14). Conclusion: If change in temperature alone can cause significant reduction in leukocytes, then it is a simple way to curtail the rate of this common yet unpleasant reaction and reduce the reaction rate at minimal cost. [ABSTRACT FROM AUTHOR]

Leukoreduction of blood products is a technique used to prevent leukocyte-induced transfusion reactions and is extensively used in human, but rarely in veterinary patients. The concentration of some coagulation proteins can be affected by the processing steps used for the preparation of leuko-reduced plasma units. In this study, we assessed the effect of leukoreduction on coagulation activity of canine plasma collected for transfusion. Ten plasma units, five obtained from non-leuko-reduced (non-LR) whole blood (WB) units and five from leuko-reduced (LR) WB units were evaluated. Prothrombin time (PT), activated partial thromboplastin time (aPTT), coagulation factor activities of factors (F) V, VIII, X, XI, and von Willebrand (vWF), fibrinogen and D-dimers content were assessed at collection (baseline value, D0) and after 7 days of frozen storage at -18°C (D7). Compared to non-LR plasma units, LR units showed a statistically significant prolonged aPTT and reduced FXI activity. Filtration had no significant effect on the other factors and parameters evaluated. Filtration-dependent changes appear to have no impact on the therapeutic quality of plasma obtained from leuko-reduced whole blood, other than for FXI activity. Further studies on a larger sample size comparing the same unit before and after leukoreduction are needed to confirm these findings. [ABSTRACT FROM AUTHOR]

Human T-cell lymphotropic virus type 1 and 2 (HTLV-1/2) screening is not mandatory in Spanish blood banks. In Catalonia, selective screening was introduced in 2008, followed by universal screening in 2011. We present herein a 10-year experience of HTLV testing in blood donors. HTLV-1/2 selective screening was performed using Ortho-Clinical Diagnostics HTLV-I/HTLV-II Ab-Capture ELISA between February 2008 and May 2009, then Abbott Prism HTLV-I/ HTLV-II assay until December 2010. Abbott Architect rHTLV-I/II assay was then used for HTLV-1/2 universal screening in pooled samples. INNO-LIA HTLV I/II Score (Fujirebio) and in-house HTLV-1/2 proviral DNA real-time PCR were used in reactive samples. Follow-up was offered to confirm HTLV-1/2 donors in Vall d’Hebron Hospital. Between 2008 and 2017, 51 blood donors were confirmed HTLV positive (46 HTLV-1, 4 HTLV-2 and 1 HTLV) out of 2,114,891 blood donations (1 in 41,468). Sixty-nine percent were female, median age was 40 years and most were born in Latin America (69%), followed by Europe (25%), Africa (4%) and Asia (2%). Screening of relatives and partners identified 12 additional HTLV-1 cases. Lookback studies did not show any HTLV-1/2 transmission. HTLV infections found in blood donors mirror epidemiological changes in the population of Spain. Consequently, HTLV should be considered a potential risk for recipients and calls for the design of optimal strategies to ensure transfusion safety.

Background: Recent studies characterizing in vitro hemostatic properties of whole blood (WB) leukoreduced (LR) with a platelet-sparing filter have described subtle, if any, changes to viscoelastic clotting; however, reductions in platelet (PLT) content and impedance aggregometry (IA) responses have been noted. The effects of filtration of WB (i.e., filter-contact effects, reduction in platelet and leukocyte count) have not been rigorously investigated as to their individual impacts on platelet IA responses.Study Design and Methods: WB units from healthy donors were collected and characterized to assess the effects of platelet-sparing leukoreduction (LR) upon the in vitro hemostatic measures of platelet IA and thromboelastometry. Further characterization of platelet IA responses was carried out in WB samples to delineate the effects of platelet count and leukocyte presence/absence upon the response.Results: WB filtration reduced the platelet count and IA responses but had no impact on viscoelastic clotting measures in fresh WB. Experiments revealed that IA responses have a linear correlation with platelet count in both apheresis platelets and WB and that passage of platelets through the WB-LR filter has no impact upon the strength of this response. Further experiments in LR WB showed that addition of autologous leukocytes back to the platelets fully restored the platelet aggregation response to pre-filtration levels.Conclusion: WB filtration results in platelet count reduction and leukocyte removal; however, platelet IA is not degraded by passage through the filter. Apparent declines in platelet IA responses can be fully attributed to the reduction in platelet count and the removal of leukocytes. [ABSTRACT FROM AUTHOR]

Background: Collection of non-leukoreduced citrate-phosphate-dextrose-adenine (CPDA-1) whole blood is performed in walking blood banks. Blood collected under field conditions may have increased risk of bacterial contamination. This study was conducted to examine the effects of WBC reduction and storage temperature on growth of Escherichia coli (ATCC® 25922™) in CPDA-1 whole blood.Methods: CPDA-1 whole blood of 450 ml from 10 group O donors was inoculated with E. coli. Two hours after inoculation, the test bags were leukoreduced with a platelet-sparing filter. The control bags remained unfiltered. Each whole blood bag was then split into three smaller bags for further storage at 2-6°C, 20-24°C, or 33-37°C. Bacterial growth was quantified immediately, 2 and 3 h after inoculation, on days 1, 3, 7, and 14 for all storage temperatures, and on days 21 and 35 for storage at 2-6°C.Results: Whole blood was inoculated with a median of 19.5 (range 12.0-32.0) colony-forming units per ml (CFU/ml) E. coli. After leukoreduction, a median of 3.3 CFU/ml (range 0.0-33.3) E. coli remained. In the control arm, the WBCs phagocytized E. coli within 24 h at 20-24°C and 33-37°C in 9 of 10 bags. During storage at 2-6°C, a slow self-sterilization occurred over time with and without leukoreduction.Conclusions: Storage at 20-24°C and 33-37°C for up to 24 h before leukoreduction reduces the risk of E. coli-contamination in CPDA-1 whole blood. Subsequent storage at 2-6°C will further reduce the growth of E. coli. [ABSTRACT FROM AUTHOR]

Background: There is a global increase in whole blood usage and at the same time, emerging pathogens give cause for pathogen reduction technology (PRT). The Mirasol PRT has shown promising results for plasma and platelet concentrate products. Treatment of whole blood with subsequent platelet survival and recovery analysis would be of global value.Study Design and Methods: A two-arm, open-label laboratory study was performed with 40 whole blood collections in four groups: non-leukoreduced non-PRT-treated, non-leukoreduced PRT-treated, leukoreduced non-PRT-treated, and leukoreduced PRT-treated. Leukoreduction and/or PRT-treatment was performed on the day of collection, then all WB units were stored at room temperature for 24 h. Sampling was performed after hold-time and after 24-h storage in RT. If PRT-treatment or leukoreduction, samples were also taken subsequently after treatment. Thirteen healthy volunteer blood donors completed the in vivo study per protocol. All WB units were non-leukoreduced and PRT-treated. Radioactive labeling of platelets from RT-stored, PRT-treated whole blood, sampling of subjects, recovery, and survival calculations were performed according to the Biomedical Excellence for Safer Transfusion Collaborative protocol.Results: In vitro characteristics show that PRT-treatment leads to increased levels of hemolysis, potassium, and lactate, while there are decreased levels of glucose, FVIII, and fibrinogen after 24 h of storage. All values are within requirements for WB. In vivo recovery and survival of platelets were 85.4% and 81.3% of untreated fresh control, respectively.Conclusions: PRT-treatment moderately reduces whole blood quality but is well within the limits of international guidelines. Recovery and survival of platelets are satisfactory after Mirasol treatment. [ABSTRACT FROM AUTHOR]

Background: Leukoreduction is a routine procedure in human transfusion medicine but is uncommon in veterinary. Objectives: To evaluate the effect of leukoreduction on the quality of canine whole blood (WB) and blood products during storage. Animals Ten canine blood donors. Methods: This is a case series study. An amount of 450 mL of blood was collected from each dog. Five WB and 5 packed red blood cells (pRBC) bags were divided into 2 units each: leukoreduced (LR) and non‐leukoreduced (nLR). RBC count, erythrocytes' mean osmotic fragility (MOF), 2,3‐diphosphoglycerate (2,3‐DPG), adenosine triphosphate (ATP), percentage of hemolysis, potassium (K), lactate, glucose, and cytokines were measured weekly from day of donation (T0) to day 35 (T35); pH, coagulation times, and clotting factors were evaluated at T0 and T35 from WB and in fresh frozen plasma after 1 year of storage. Results: Leukoreduction showed positive effects on lactate (T35: LR WB 14.42 mmol/L SD 2.71, nLR WB 22.42 mmol/L SD 1.86, LR pRBC 20.88 mmol/L SD 2.65, nLR pRBC 36.81 mmol/L SD 2.34; P <.0001), pH (T35: LR WB 6.88 SD 0.16, nLR WB 6.69 SD 0.20, P =.02; LR pRBC 6.57 SD 0.23, nLR pRBC 6.22 SD 0.11; P <.001), and K (LR pRBC 4.08 mmol/L SD 0.88, nLR pRBC 5.48 mmol/L SD 0.90; P <.001). Increasing values of IL8 were observed in nLR units during storage (T0: 4167 ± 11 888 pg/mL; T35: 6367 ± 11 612 pg/mL). Conclusion and Clinical Importance: LR blood units are recommended to critically ill dogs with marked inflammatory conditions. [ABSTRACT FROM AUTHOR]

We report five cases of malignant pertussis, a rare but life‐threatening illness. Current therapies include supportive care and leukoreduction. Notably, leukoreduction might be more effective when initiated prior to the development of organ failure and pulmonary hypertension. [ABSTRACT FROM AUTHOR]

Summary: Objectives: In this study, we aimed to determine the consequences of different amounts of leukocyte transfusion on the outcome of patients undergoing cardiac surgery. Design This was a prospective, single‐blinded cohort study conducted for 1 year from July 2018 to June 2019. Setting: The study setting was the Department of Transfusion Medicine, along with Cardiac Anaesthesia, Cardiac Surgery and Cardiac biochemistry departments in a tertiary care cardiac centre. Participants: A total of 150 patients undergoing cardiac surgery during the study period were divided into three groups (50 in each): Leukofiltered (LR), Buffy coat depleted (BCD) and Non‐leukoreduced (NLR). Intervention: The intervention was intra‐ and postoperative transfusion of packed red blood cells (PRBCs) having different amounts of leukocytes. Measurements and main results: Patient details about length of intensive care unit (ICU) and hospital stay, blood usage, inotropic drug duration, mechanical ventilation, urine output and infection were recorded from the patient data sheet, whereas patients were followed up for 30 days post‐operation, and any mortality was noted. Haematological parameters and biochemical parameters for renal function test were analysed on pre‐ and post‐surgical days 1, 3, 5 and 7, whereas on postoperative days 1 and 7, cytokine‐like FAS ligands, Interleukin‐10 (IL‐10) and Interferon‐γ (INF‐γ) were tested. Patients in all three groups received an average of four, two and two units of packed red blood cells, platelets and fresh frozen plasma, respectively. There was a statistically significant (P <.05) rise in total leukocyte, neutrophil and lymphocyte count in all three groups from day 0 to day 3, but it reduced to preoperative level on day 5. There was shorter ICU and hospital stay in the LR group of patients (46 ± 19.9 hours and 7.5 ± 2.4 days) compared to NLR (52.1 ± 24.2 hours and 7.9 ± 4.1 days) and BCD (53.3 ± 26.7 hours and 8.8 ± 3.1 days) group of patients, but it was statistically non‐significant. The duration of mechanical ventilation was significantly lesser in LR group patients (10.2 ± 6.2 hours) as compared to NLR group (14.7 ± 12.7 hours). On risk ratio calculation of developing postoperative kidney injury, the NLR group had 1.3 and 2.6 times more risk compared to the BCD and LR groups, respectively. On postoperative days 1 and 7, FAS‐L levels significantly increased in all three group of patients, whereas IL‐10 increased in the NLR and BCD groups and decreased in the LR group non‐significantly. The INF‐γ levels decreased on day 1 in the NLR and BCD groups but increased in the LR group, but it was inversed on day 7. Conclusion: Depletion of leukocytes decreased Transfusion Related Immunomodulation (TRIM) effects in patients undergoing cardiac surgery, but this also depends on the degree of leukoreduction. As found in our study, leukofiltration is more effective compared to buffy‐coat depletion only. [ABSTRACT FROM AUTHOR]

Background: Leukodepletion of whole blood-based perfusates remains a challenge in experimental models of ex vivo perfusion. This study investigated the leukoreduction efficacy of the commonly used LeukoGuard LG Arterial and BC2 Cardioplegia filters. Methods: Eleven liters of washed porcine blood was used to evaluate the filtration efficiency of LG (n = 6) and BC2 (n = 5) filters. Filter efficacy was tested by passing 1 L of washed blood through each filter. Complete blood count was performed to detect a reduction of white blood cells, red blood cells, and hemoglobin concentration. Results: The BC2 Cardioplegia filter showed a significant reduction in white blood cell count (13.16 ± 4.2 × 103 cells/μL pre-filtration, 0.62 ± 0.61 cells/μL post-filtration, p = 0.005), red blood cell count (9.18 ± 0.16 × 106 cells/μL pre-filtration, 9.02 ± 0.16 × 106 cells/μL post-filtration, p = 0.012) and hemoglobin concentration (15.89 ± 0.66 g/dL pre-filtration, 15.67 ± 0.83 g/dL post-filtration, p = 0.017). Platelet reduction in the LG filter group was statistically significant (13.23 ± 13.98 × 103 cells/μL pre-filtration, 7.15 ± 3.31 × 103 cells/μL post-filtration, p = 0.029), but no difference was seen in the BC2 group. There was no significant difference in white blood cell count in the LG filter group (10.12 ± 3.0 × 103 cells/μL pre-filtration, 10.32 ± 2.44 × 103 cells/μL post-filtration, p = 0.861). Conclusion: Our results suggest that the LG filter should not be used in ex vivo perfusion circuits for the purpose of leukodepletion. The BC2 filter can be used in EVP circuits with flow rates of less than 350 mL/min. Alternatively, perfusate may be leukodepleted before perfusion. [ABSTRACT FROM AUTHOR]

Estimation of residual leukocytes in blood components after leukodepletion is crucial for assessment of quality. Flow cytometry (FC) and Nageotte hemocytometer are the most widely accepted methods for counting residual white blood cells (rWBCs) in leucocyte-depleted (LD) blood components. The objective of this study was to compare use of Nageotte counting chamber and FC for quality control of leukodepleted red cell units. A prospective, observational study was conducted in the department of Transfusion Medicine. A total of 80 whole blood donations from healthy donors were subjected to testing by FC and Nageotte hemocytometer for estimation of rWBC in duplicate. Additionally, ten personnel attempted a survey for ease of use of FC. Number of rWBC detected by flow cytometer were between 1 WBC/μL and 28 WBCs/μL whereas that detected by Nageotte's chamber were between 0 WBC/μL (lowest) and 5 WBCs/μL. Coefficient of variation was found to be 87.36% by Nageotte hemocytometer method and 43.26% by FC. Linear regression analysis did not show any correlation (R-squared = 0.01, p = 0.13) between the two methods which signifies that the two methods cannot be used interchangeably. Pearson's correlation coefficient showed a weak relation between results obtained by the two methods. Inter-observer variation was found to be significant with use of Nageotte hemocytometry. Survey for ease of use of FC indicated acceptability of FC with favorable scores. Flow cytometric technique provides a reproducible and objective tool for counting rWBC in leukodepleted blood components compared with the Nageotte hemocytometer. [ABSTRACT FROM AUTHOR]

Background: Neutrophil extracellular traps (NETs), webs of DNA and citrullinated histones extruded from activated neutrophils cause transfusion‐related acute lung injury. Supernatants of stored red blood cell (RBC) units might promote NETosis in neutrophils from the units or from transfusion recipients. Hypotheses: (1) NETs form during storage of canine RBC, (2) leukoreduction (LR) before storage of RBC reduces NETosis, and (3) supernatant from stored, nonleukoreduced (NLR) RBC units induces NETosis in healthy canine neutrophils modeling transfusion recipients. Animals Six healthy purpose‐bred research dogs were utilized for blood donation. Methods: Prospective controlled study. RBC units were collected from each dog, aseptically divided into 2 equal subunits, 1 of which was leukoreduced, and stored for 42 days. Stored units were sampled biweekly for quantification of NET markers citrullinated histone H3 (Western blot) and cell‐free DNA (cfDNA) (DNA dye binding). Unit supernatants were applied ex vivo to canine neutrophils and extracellular DNA release representing NETosis was assessed. Results: Markers of NETs increased during RBC storage (cfDNA P <.0001 and citrullinated H3 P =.0002) and were higher in NLR than LR units (day 42 LR cfDNA 0.34 ± 0.82 ng/mL vs day 42 NLR 1361.07 ± 741.00 ng/mL, P <.0001; day 42 LR citrullinated H3 0.19 ± 0.13 AU vs NLR 0.57 ± 0.34 AU, P =.007). Isolated neutrophils did not form NETs when exposed to stored canine RBC supernatant. Conclusions and Clinical Importance: NETosis occurs in stored canine NLR RBC units, and is attenuated by LR before storage. NETs might be mediators of transfusion reactions. [ABSTRACT FROM AUTHOR]

Background: The ability of tick-borne agents to survive in stored blood bags is a key factor for their transmissibility by blood transfusion. The aim of this study was to evaluate the survival and potential infectivity of Rickettsia conorii (RC) in artificially contaminated canine whole blood (WB) and in leukoreduced whole blood (LR-WB) during the storage period. Methods: RC was cultured on L929 cells. We used a one-week 25-cm2 flask with 70–80% of L929 infected cells to prepare the bacterial inoculum by pelleting cells and suspending the pellet in the donors' serum. We infected five 100 ml WB units with RC within 2 h from the collection and maintained it at room temperature for 4 h prior to refrigeration. We filtered 50 ml of each WB bag to obtain leukoreduced WB (LR-WB) at day 1 post-infection (dpi). We checked WB and LR-WB bags at 1, 4, 7, 14, 21, 28, 35 dpi for RC presence and viability through real-time PCR (rPCR) for DNA and mRNA, respectively, and by isolation. Identification of isolates was confirmed by indirect immunofluorescence and rPCRs. Results: RC survived for the entire storage period in both whole and leukoreduced blood. All bags contained viable bacteria until 7 dpi; RC viability generally decreased over time, particularly in LR-WB bags where the isolation time was longer than in WB. Viable bacteria were still isolated at 35 dpi in 3 WB and 3 LR-WB. Conclusions: Leukoreduction reduced but did not eliminate RC in infected units. The survival and infectivity of RC in canine blood during the storage period may represent a threat for recipients. [ABSTRACT FROM AUTHOR]

Leukoreduction of blood products is a technique used to prevent leukocyte-induced transfusion reactions and is extensively used in human, but rarely in veterinary patients. The concentration of some coagulation proteins can be affected by the processing steps used for the preparation of leuko-reduced plasma units. In this study, we assessed the effect of leukoreduction on coagulation activity of canine plasma collected for transfusion. Ten plasma units, five obtained from non-leuko-reduced (non-LR) whole blood (WB) units and five from leuko-reduced (LR) WB units were evaluated. Prothrombin time (PT), activated partial thromboplastin time (aPTT), coagulation factor activities of factors (F) V, VIII, X, XI, and von Willebrand (vWF), fibrinogen and D-dimers content were assessed at collection (baseline value, D0) and after 7 days of frozen storage at −18 °C (D7). Compared to non-LR plasma units, LR units showed a statistically significant prolonged aPTT and reduced FXI activity. Filtration had no significant effect on the other factors and parameters evaluated. Filtration-dependent changes appear to have no impact on the therapeutic quality of plasma obtained from leuko-reduced whole blood, other than for FXI activity. Further studies on a larger sample size comparing the same unit before and after leukoreduction are needed to confirm these findings.

Patients presenting with hyperleukocytosis secondary to acute leukemia, with total leukocyte count or blast count more than 100,000/μL are often considered for leukapheresis, especially if clinical signs of leukostasis are present. Leukostasis is often associated with high morbidity and mortality in patients with leukemic processes. The main goal of management of hyperleukocytosis and/or leukostasis is to reduce the blast count before initiation of chemotherapy. Leukapheresis is often used prophylactically to prevent leukostasis or to provide symptomatic relief. We, as transfusion medicine specialists, present our experience of doing therapeutic leukapheresis in patients presenting with hyperleukocytosis with or without presenting features of leukostasis.

We report a death from transfusion-transmitted anaplasmosis in a 78-year-old man. The patient died of septic shock 2 weeks after a perioperative transfusion with erythrocytes harboring Anaplasma phagocytophilum. The patient’s blood specimens were positive for A. phagocytophilum DNA beginning 7 days after transfusion; serologic testing remained negative until death.

Storage lesions (SLs) occur when the red blood cell quality is altered during the preservation of blood units. Pre-storage leukoreduction would limit the number of SLs. The aims of this study were to evaluate the effectiveness of a leukoreduction filter for human use and the effect of pre-storage leukoreduction on some ematobiochemical parameters in stored canine whole blood. Seven canine blood units were tested. Each one was divided into two units—one leukoreduced (LRWB) and one non-leukoreduced (nLRWB). On each unit, we determined the complete blood count (CBC), lactate-dehydrogenase (LDH), electrolytes (Na+, K+, Cl−), morphological index (MI) and hemolysis, on storage days 0, 7, 14, 21, 28, 35, and 42. Leukoreduction allowed a 98.30% recovery of the RBC count, retaining 99.69% and 94.91% of WBCs and PLTs, respectively. We detected a significant increase of LDH and MI with strongly higher values in nLRWB compared to LRWB. A progressive increase in electrolytes and LDH concentrations was observed as indices of stored hemolysis. LDH showed significantly lower values in LRWB units compared to nLRWB, suggesting its release from leukocytes. In the majority of units, hemolysis reached 1% on the 42nd day of storage. We assert the human leukoreduction filter effectiveness on canine whole blood, and we recommend using nLRWB before day 14, especially for critically ill patients. The difference of the basal hemolysis (day 0) percentages observed between subjects suggests that more studies should be performed to confirm a possible inter-individual donor biological variability of RBC membrane resistance, as happens in humans.

Biochemical and metabolic changes in stored RBC may influence the clinical outcome. We aimed to study the temporal changes in the biochemical parameters and the effect of buffy-coat reduction on RBC storage lesions. A prospective observational study was conducted on fifteen RBC units five each of buffy coat reduced CPD/SAGM (quadruple bags), non-buffycoat reduced CPD/SAGM (triple bags) and non-buffycoat reduced CPDA (double bags). Biochemical parameters such as K+, LDH, pH plasma hemoglobin and percentage hemolysis were measured sequentially on day 7,14, 21, 28, 35 and 42. The data was analyzed using SPSS version 20. Extracellular K+ and LDH increased rapidly starting from the first week of storage. And the all the parameters including percentage hemolysis were significantly higher in RBC stored in CPDA (double bags) compared to that stored in SAGM (triple and quadruple). The difference observed in buffy-coat reduced units in comparison to the non-leukocyte reduced units were statistically not significant. The quality of red cells stored in SAGM was superior to that suspended in CPDA measured in terms of percent hemolysis, plasma hemoglobin, potassium and LDH. There was no effect of buffy-coat leukocyte reduction on the red cell storage lesion. [ABSTRACT FROM AUTHOR]