The complexities of transfusion reactions: Coexistence of a delayed haemolytic transfusion reaction and post-transfusion purpura.

BACKGROUND AND OBJECTIVES: Immune-mediated acute or delayed transfusion reactions occur when there is immunological incompatibility between transfused blood products and recipient's antibodies. Acute haemolytic transfusion reactions occur within 24 h and are delayed after 24 h up to 10 days following transfusion, whereas post-transfusion purpura (PTP) typically occurs 7-10 days post-transfusion. We present a case of a previously transfused and recently post-partum female who developed both delayed haemolytic transfusion reaction (DHTR) and PTP. CASE REPORT: A 42-year-old woman, G2P1, with non-alcoholic liver disease, portal hypertension and previous transfusion history with allogeneic anti-E, developed a severe DHTR and PTP following a complicated post-partum course and multiple transfusions. The antenatal and initial post-partum pre-transfusion antibody screens were negative. Subsequently five red cell antibodies, including anti-c, anti-Fya, anti-Jkb and anti-S and the reappearance of anti-E were, however, identified during follow-up investigations along with the anti-platelet antibody HPA-3a and human leukocyte antigen class I antibodies. Anti-E, anti-Jkb and anti-S were eluted from the circulating red blood cells. CONCLUSION: To our knowledge, there have been only two other case reports of DHTR and PTP occurring in the same patient.

The impact of COVID-19 outbreak on the Transfusion Medicine Unit of a Northern Italy Hospital and Cancer Centre.

BACKGROUND AND OBJECTIVES: The first wave of coronavirus disease-2019 (COVID-19) dramatically affected the Transfusion Medicine Unit of the Azienda Unità Sanitari Locale - Istituto di Ricovero e Cura a Carattere Scientifico (AUSL-IRCCS) di Reggio Emilia, which faced a total rearrangement of the procedures for donors and patients. This study aims to assess the major implications of COVID-19 on our department, focusing on the blood transfusion chain and therapies, in order to support transfusion specialists in seeking efficient ways to face similar future emergencies. MATERIALS AND METHODS: This retrospective study compares our Transfusion Medicine Unit data collected between February and May 2020 with the same period in 2017-2019. Data on red blood cells and platelets donations, transfusions and clinical procedures were collected as aggregates from our internal electronic database. RESULTS: During the lockdown, donor centres were re-organized to reduce the risk of contagion and avoid unnecessary blood collection. Blood donations were re-scheduled to meet the decrease in elective surgery; consequently, plateletapheresis was implemented to supply the reduction of buffycoat-derived platelets. Transfusions significantly decreased together with orthopaedic and vascular surgery, while they were only marginally diminished for both cancer and onco-haematological patients. Reduced procedures for inpatients and outpatients were matched by remote medicine, addressing the need of a constant healthcare support for patients with chronic diseases. CONCLUSIONS: The described measures were adopted to avoid excessive blood collection and expiration, guarantee the safety of our ward (for both patients and staff) and supply the necessary transfusion therapies. These measures may support the development of appropriate risk management plans and safety procedures for other hospitals and transfusion services that have to face similar events.

Effect of the COVID-19 pandemic on blood donations and transfusions in Nigeria - A multi-facility study of 34 tertiary hospitals.

Background: The coronavirus disease 2019 (COVID-19) pandemic affected blood supplies globally. Mobile blood drive campaigns halted, and voluntary blood donations reduced, challenging available blood supplies. Furthermore, fears of virus transmission led to deferrals of elective surgeries and non-urgent clinical procedures with noticeable declines in blood donations and transfusions. Aims: We aimed to assess the effect of the COVID-19 pandemic on the number of blood donations and transfusions across the country by blood product type across various hospital departments. Materials and Methods: A retrospective descriptive study was conducted to determine the impact of the COVID-19 pandemic on blood services in 34 tertiary hospitals in Nigeria, comparing January to July 2019 (pre-COVID-19) to January to July 2020 (peri-COVID-19). Data were collected from the country's web-based software District Health Information System, Version 2 (DHIS2). Results: A 17.1% decline in numbers of blood donations was observed over the study period, especially in April 2020 (44.3%), a 21.7% decline in numbers of blood transfusions, especially in April 2020 (44.3%). The largest declines in transfusion were noted in surgery department for fresh frozen plasma (80.1%) [p = 0.012] and accident and emergency department transfusion of platelets (78.3%) [p = 0.005]. The least decline of statistical significance was observed in internal medicine transfusions of whole blood (19.6%) [p = 0.011]. Conclusions: The COVID-19 pandemic significantly affected the numbers of blood donations and transfusions in Nigeria. Strengthening blood services to provide various blood components and secure safe blood supplies during public health emergencies is therefore critical.

In vitro phagocytosis of liquid-stored red blood cells requires serum and can be inhibited with fucoidan and dextran sulphate.

BACKGROUND AND OBJECTIVES: Red-blood-cells (RBCs) undergo structural and metabolic changes with prolonged storage, which ultimately may decrease their survival after transfusion. Although the storage-induced damage to RBCs has been rather well described biochemically, little is known about the mechanisms underlying the recognition and rapid clearance of the damaged cells by macrophages. MATERIALS AND METHODS: We, here, used a murine model for cold (+4°C) RBC storage and transfusion. Phagocytosis of human or murine RBCs, liquid stored for 6-8 weeks or 10-14 days, respectively, was investigated in murine peritoneal macrophages. RESULTS: The effects of storage on murine RBCs resembled that described for stored human RBCs with regard to decreased adenosine triphosphate (ATP) levels, accumulation of microparticles (MPs) during storage, and RBC recovery kinetics after transfusion. Under serum-free conditions, phagocytosis of stored human or murine RBCs in vitro was reduced by 70-75%, as compared with that in the presence of heat-inactivated fetal calf serum (FCS). Human serum promoted phagocytosis of stored human RBCs similar to that seen with FCS. By adding fucoidan or dextran sulphate (blockers of scavenger receptors class A (SR-A)), phagocytosis of human or murine RBCs was reduced by more than 90%. Phagocytosis of stored human RBCs was also sensitive to inhibition by the phosphatidylinositol 3 kinase-inhibitor LY294002, the ERK1/2-inhibitor PD98059, or the p38 MAPK-inhibitor SB203580. CONCLUSION: RBCs damaged during liquid storage may be recognized by macrophage SR-A and serum-dependent mechanisms. This species-independent recognition mechanism may help to further understand the rapid clearance of stored RBCs shortly after transfusion.

An exploration of the advantages of automated titration testing: low inter-instrument variability and equivalent accuracy for ABO and non-ABO antibody titres relative to tube testing.

BACKGROUND AND OBJECTIVES: Obtaining IgM and IgG titres is important in numerous clinical situations, including solid-organ transplant, obstetrics, and for testing of out-of-group plasma-containing components. Tube method is the most prevalent testing modality, though it is both labour-intensive and known for intra- and inter-laboratory variability. The utility of automated gel testing as a method to improve both inter- and intra-laboratory reproducibility is unknown. MATERIALS AND METHODS: Two academic centres participated in a study evaluating automated gel titreing. Group O plasma samples were used to measure titres of antibodies against ABO (IgM) with buffered gel cards and 4 minor and minor red-blood-cell antigens (IgG) anti-IgG gel cards. Multiple ORTHO VISION automated analyzers were used to assess inter-instrument variation. A subset of ABO (IgM) samples were compared between laboratories to evaluate inter-laboratory variability. Multiple samples were titred by tube and by automated gel technology to determine similarity of results. RESULTS: Testing demonstrated no significant difference between analysers or between sites when performing automated titrations (P ≥ 0·99). Non-ABO IgG titres were evaluated and demonstrated little inter-instrument variability. The IgM anti-A and -B titres obtained by automated gel testing were neither consistently higher nor lower than tube titres. Greater than 90% of titre values were within one dilution. CONCLUSION: Based on this study, our data suggest that titreing by automated gel testing is both highly reproducible (IgM and IgG) and does not differ significantly from manual tube testing results of direct agglutination (IgM).

Colloid osmotic pressure of contemporary and novel transfusion products.

BACKGROUND AND OBJECTIVES: Colloid osmotic pressure (COP) is a principal determinant of intravascular fluid homeostasis and a pillar of fluid therapy and transfusion. Transfusion-associated circulatory overload (TACO) is a leading complication of transfusion, and COP could be responsible for recruiting additional fluid. Study objective was to measure COP of blood products as well as investigate the effects of product concentration and storage lesion on COP. MATERIALS AND METHODS: Three units of each product were sampled longitudinally. COP was measured directly as well as the determinants thereof albumin and total protein. Conventional blood products, that is red blood cell (RBC), fresh-frozen plasma (FFP) and platelet concentrates (PLTs), were compared with their concentrated counterparts: volume-reduced RBCs, hyperconcentrated PLTs, and fully and partially reconstituted lyophilized plasma (prLP). Fresh and maximally stored products were measured to determine changes in protein and COP. We calculated potential volume load (PVL) to estimate volume recruited using albumin's water binding per product. RESULTS: Colloid osmotic pressure varies widely between conventional products (RBCs, 1·9; PLTs, 7·5; and FFP, 20·1 mmHg); however, all are hypooncotic compared with human plasma COP (25·4 mmHg). Storage lesion did not increase COP. Concentrating RBCs and PLTs did not increase COP; only prLP showed a supraphysiological COP of 47·3 mm Hg. The PVL of concentrated products was lower than conventional products. CONCLUSION: Colloid osmotic pressure of conventional products was low. Therefore, third-space fluid recruitment is an unlikely mechanism in TACO. Concentrated products had a lower calculated fluid load and may prevent TACO. Finally, storage did not significantly increase oncotic pressure of blood products.

Red blood cell utilization and transfusion triggers in patients diagnosed with chronic lymphocytic leukaemia in Iceland 2003-2016.

BACKGROUND AND OBJECTIVES: Revised Icelandic guidelines proposed a restrictive haemoglobin (Hb) threshold of 70 g/l for red blood cell (RBC) transfusions in general, but 100 g/l for malignancies/bone marrow suppression. Chronic lymphocytic leukaemia (CLL) is frequently complicated by anaemia. The objective was to investigate RBC transfusion practices in CLL. MATERIALS AND METHODS: This retrospective nation-wide study utilized an Icelandic registry of CLL patients diagnosed between 2003 and 2016. Medical records were reviewed and haemoglobin transfusion triggers compared for two periods: Earlier (2003-2012) and latter (2013-2017). RESULTS: Two hundred and thirteen patients were diagnosed with CLL over the period whereof 77 (36·2%) received RBC transfusion(s). Median time from diagnosis to first transfusion was 2·2 years. Higher age, Rai stage 3/4 at diagnosis (P < 0·05) and chemotherapy (P < 0·001) were associated with increased odds of transfusions. Shorter time to first transfusion correlated with higher age (P < 0·001) and Rai stage (P = 0·02) at diagnosis. The mean Hb trigger was 90·4 and 81·2 in the earlier and latter period respectively (P = 0·01). This difference in Hb triggers was most pronounced in patients without documented bone marrow involvement, or 80·5 g/l compared to 93·5 g/l (P = 0·004). The median time from diagnosis to transfusion was longer in the latter period (2·9 years vs. 1·6 years, P = 0·01). After RBC transfusions the survival decreased significantly (P < 0·001). CONCLUSION: One-third of CLL patients received RBC transfusions but few were heavily transfused. Older age, Rai stage, and chemotherapy predicted RBC use. The Hb transfusion trigger decreased over time while time to first RBC transfusion increased. RBC transfusions predict poor survival.

Sex-mismatched red blood cell transfusions and mortality: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVES: Selection of a compatible red blood cell (RBC) unit does not include matching for donor sex. This systematic review and meta-analysis aims to summarize the evidence examining the impact of sex-mismatched RBC transfusion on recipient mortality. MATERIALS AND METHODS: Ovid MEDLINE, Ovid EMBASE, CINAHL, PubMed, Web of Science and the Cochrane Database of Systematic Reviews were searched from inception up to 23 November 2018. Randomized controlled trials and observational studies were included in the search. Eligible studies reported on the impact of sex-matched compared to sex-mismatched RBC transfusion on recipient mortality. Two investigators independently extracted data and assessed study quality. A three-level meta-analytic model was applied to emphasize the unknown dependence among the effect sizes. RESULTS: Five retrospective observational studies (n = 86 737) were included; no RCTs were found. Sex-mismatched RBC transfusions were associated with a higher risk of death compared with sex-matched transfusions (pooled hazard ratio [HR]: 1·13; 95% confidence interval [CI]: 1·02-1·24). In the subgroup of cardiovascular surgery (n = 57 712), there was no significant increase in mortality with sex-mismatched transfusions (pooled HR: 1·08; 95% CI: 0·95-1·22). The data were prone to confounding, selection bias and reporting bias. Certainty of the evidence was very low. CONCLUSION: Sex-mismatched RBC transfusions were associated with an increased risk of death in this pooled analysis. However, the certainty of the evidence was very low from observational studies. The need to match donor and recipient sex for transfusions requires further investigation because of the potential widespread impact.

Evaluation of DMSO dextrose as a suitable alternative for DMSO dextran in cord blood cryopreservation.

BACKGROUND AND OBJECTIVES: Umbilical cord blood is considered an alternative source of hematopoietic stem cells. Standard banking procedures use 50/55% DMSO in dextran 40 for cryopreservation and dextran-based solutions for thawing, however, due to the potential risk of crystallization of dextran, dextran 40 approved for clinical use has become limited or unavailable. This affects cryopreservation and thawing procedures. Carbohydrates, in particular sucrose, trehalose and glucose, have been shown to be effective in reducing cell damage during dehydration and have cryoprotective potential. We aim to study a 50/55% DMSO in 5% dextrose cryopreservation solution as an alternative to DMSO dextran. MATERIALS AND METHODS: Eighteen samples were divided into two aliquots and cryopreserved, one using standard solution and the other with DMSO dextrose experimental solution. Both aliquots were thawed and diluted with PBS or saline. Total nucleated cells counts, 7-AAD viability of CD45+ cells and recovery of CD34+ viable cells were assessed on thawed samples and compared between pair of aliquots. RESULTS: No differences were observed in the total nucleated cells recovery between cryopreservation solutions, however, higher viability and CD34+ viable cells recoveries were observed using the experimental solution. CONCLUSION: Results showed that DMSO dextrose cryopreservation solution had better results than the standard solution when thawed in an isotonic solution. This indicates that DMSO dextrose is probably a better alternative for direct infusion or when dextran thawing solutions are unavailable. Viability of CD45+ cells and recovery of CD34+ viable cells have positive correlation with engraftment, highlighting the relevance of the optimization of the cryopreservation and thawing process.

Recombinant erythropoietin as alternative to red cell transfusion in sickle cell disease.

Disturbances in the physiological regulation of erythropoietin (EPO) in patients with sickle cell disease (SCD) may contribute to worsening anaemia and increased transfusion requirements, but the use of recombinant EPO in this group of patients is controversial. The objective of this study was to evaluate the use of this drug in adult patients with SCD and its effects on haemoglobin levels and transfusion requirements. We conducted a retrospective analysis at the University of Campinas, with nineteen adults with a diagnosis of SCD (HbSS and HbS/ß+ thalassaemia), who had received at least 1 year of EPO therapy between 2007 and 2014. Haemoglobin concentrations and trends of variation in transfused RBC volumes were compared before and after EPO administration. We observed that seven patients had a good response to treatment (Hb increment higher than 1·5 g/dl) and nine had a partial response (0·5-1·5 g/dl increment) and there was a significant decrease in the need for transfusion amongst those who usually required regular transfusions. There were no increases in the rates of vaso-occlusive crisis or venous thromboembolism in comparison to the year before the onset of the therapy. Erythropoietin therapy led to a marked increase in haemoglobin concentration with a concomitant decrease in the demand for transfusion. Considering all complications related to allogeneic transfusion, we believe that EPO therapy represents an important therapeutic tool in sickle cell anaemia.

Rapid bedside rejuvenation of red blood cell with an autologous cell salvage device.

BACKGROUND AND OBJECTIVES: During storage, red blood cells (RBCs) undergo physicochemical changes which affect the quality, function, and in vivo survival of transfused packed RBCs (pRBC). Changes include decreased 2,3-diphosphoglycerate (2,3-DPG) levels, decreased ATP, changes in mechanical properties and oxidative injury. RBC rejuvenation is a method used to increase levels of 2,3-DPG and ATP in pRBCs. This process requires incubating the pRBCs with a rejuvenation solution and subsequent washing. Standard blood bank protocols using the COBE 2991 Cell Processor require several hours of preparation. The objective of this study was to verify if a bedside protocol for rejuvenating pRBC and washing with the Sorin Xtra autologous cell salvage system could be used. MATERIALS AND METHODS: Outdated pRBC units were obtained and rejuvenated in a model operating suite using a dry air incubator for 1 h at 37°C. Six units of pRBCs were pre-diluted with saline (1000 ml) and six units were not pre-diluted with saline. All units were washed with normal saline (1000 ml) using an apheresis-design cell salvage device in manual mode and wash volume set to 3000 ml. Samples were collected and analyzed for standard RBC quality parameters at baseline and post-wash. RESULTS: Total pRBC wash efficiency was 94% ± 12% at a final hematocrit of 67.7 ± 5.9% while maintaining post-wash hemolysis 0.24 ± 0.12 %. Pre-dilution prior to washing did not confer statistically significant differences in final RBC quality parameters with the notable exceptions of calculated hemolysis and supernatant potassium levels (P < 0.05). The washing process can be completed within 10 min. The post-wash RBC parameters are appropriate for immediate transfusion to patients.

Epidemiology of chronic red-cell transfusion recipients in Sweden and Denmark-a 10 year follow-up study.

BACKGROUND AND OBJECTIVES: Chronic red-cell transfusions may be an indispensable part of patient treatment and may require early intervention to avoid adverse transfusion effects. The population of chronic transfusion recipients including common diagnoses and survival remains poorly characterised. Thus, the objective was to examine the complete range of chronic transfusion recipients, including demographic and patient characteristics and survival. MATERIALS AND METHODS: All patients who received their first transfusion in Sweden or Denmark from January 1, 2002 to December 31, 2010 were followed up for subsequent transfusion episodes until December 31, 2012. Data on patient characteristics at time of the first and subsequent transfusions were retrieved from the national registers. We estimated the proportion of transfused patients who experienced 20 or more red-cell transfusion episodes (with an episode defined as all transfusions received 4 days or less apart) and characterised this patient population with respect to diagnoses, demographics and survival. RESULTS: Among 893 117 first time red-cell transfusion recipients, 6157 (0·7%) experienced 20 or more episodes in total. The most common diagnoses among these patients were haematologic malignancies followed by non-haematologic malignancies and non-malignant blood and immune system related diseases. On average, chronically transfused patients had a median survival of less than 1 year following their 20th transfusion episode. CONCLUSION: This study provides an overview of patient characteristics related to repeat red-cell transfusions and of the amount of red-cell transfusion episodes administered during a 10-year period in two countries. Patients who become chronically transfused suffer from diseases with poor prognosis.

Extending shelf life of dithiothreitol-treated panel RBCs to 28 days.

BACKGROUND: Daratumumab (DARA) causes non-specific results in indirect agglutination testing (IAT). Dithiothreitol (DTT) treatment of panel red blood cells (RBCs) abolishes DARA interference. The objective of our study was to extend stability of DTT-treated panel RBCs to 28 days through application of a commercially available panel RBC stabilizer. MATERIALS AND METHODS: Serological antigen typing and IAT using DARA sera and DARA plasma spiked with weakly reacting alloantibodies was performed up to 28 days after DTT treatment and stabilization. RESULTS: DTT treatment resulted in loss of Fy-antigen expression on some panel RBCs. Antigen profiles of stabilized, DTT-treated panel RBCs remained stable. Alloantibodies in DARA sera and DARA plasma were reliably detected. CONCLUSIONS: Application of a commercially available RBC stabilizer extends shelf life of DTT-treated panel RBCs to 28 days.

Changes in circulating inflammatory markers following febrile non-haemolytic transfusion reactions to leucoreduced red cells.

It would be desirable to be able to distinguish fever as a result of febrile non-haemolytic transfusion reactions (FNHTR) from other febrile conditions. To further characterize the inflammatory feature of FNHTR, we measured a large panel of inflammatory markers in pre- and posttransfusion plasma samples from patients with and without FNHTR following the transfusion of leucoreduced red blood cells. As FNHTR patients only displayed a significant increase in IL-6, we conclude that changes in plasma cytokine levels during FNHTR are unlikely to be used diagnostically. An incidental finding of a distinct cytokine pattern in pretransfusion samples from FNHTR patients warrants further investigations, as it might be used to characterize the nature of FNHTR and to predict the risk of these adverse events.

Patient blood management knowledge and practice among clinicians from seven European university hospitals: a multicentre survey.

BACKGROUND AND OBJECTIVES: The aim of this survey was to evaluate the knowledge about Patient Blood Management (PBM) principles and practices amongst clinicians working in seven European hospitals participating in a European Blood Alliance (EBA) project. MATERIALS AND METHODS: A web-based questionnaire was sent to 4952 clinicians working in medical, surgery and anaesthesiology disciplines. The responses were analysed, and the overall results as well as a comparison between hospitals are presented. RESULTS: A total of 788 responses (16%) were obtained. About 24% of respondents were not aware of a correlation between preoperative anaemia (POA) and perioperative morbidity and mortality. For 22%, treatment of POA was unlikely to favourably influence morbidity and mortality even before surgery with expected blood loss. More than half of clinicians did not routinely treat POA. 29%, when asked which is the best way to treat deficiency anaemia preoperatively, answered that they did not have sufficient knowledge and 5% chose to 'do nothing'. Amongst those who treated POA, 38% proposed red cell transfusion prior to surgery as treatment. Restrictive haemoglobin triggers for red blood cell transfusion, single unit policy and reduction of number and volumes of blood samples for diagnostic purposes were only marginally implemented. CONCLUSION: Overall, the responses indicated poor knowledge about PBM. Processes to diagnose and treat POA were not generally and homogeneously implemented. This survey should provide further impetus to implement programmes to improve knowledge and practice of PBM.

Junior doctors' perspectives on transfusion education in Australia.

BACKGROUND: Early postgraduate training is a critical period to develop skills and to influence future clinical practice. Little is known about Australian junior doctors' existing transfusion knowledge and its application in patient care. This study explored their transfusion practice education preferences, developed tools to assist their practice and assessed the usefulness of these tools. METHODS: A design-based study was conducted in two phases from April 2016 to March 2017. Phase 1 involved focus group sessions in six hospitals. Transcripts of audio recordings were analysed using thematic analysis. Findings were considered when developing transfusion practice support tools. Phase 2 surveyed junior doctors' response to the tools provided during orientation in five hospitals. Participation was voluntary. RESULTS: Fifty-two junior doctors participated in the focus groups. Their priority was to be able to practice safely, appropriately and confidently. Preferred format for transfusion learning included expert-led face-to-face education; printed tools, for example lanyard cards; and for one app that covers essential aspects of transfusion practice. Adverse events management and practical transfusion prescribing were topics of most importance. Thirty-nine survey respondents found the transfusion practice support tools useful and recommended their use to complement practice. CONCLUSION: There is a need for improved education to ensure best transfusion practice and patient outcomes. Australian junior doctors want immediate, practical, reliable transfusion information from credible sources to support them in practicing safely and confidently. Their educational needs are driven by real-time patient management. Promotion of the available resources and tools provided by the blood sector is important.

Transfusion-transmitted hepatitis B virus (HBV) infection from an individual-donation nucleic acid (ID-NAT) non-reactive donor.

Lookback was initiated upon notification of an acute HBV infection in a repeat Irish donor, 108 days post-donation. The donation screened non-reactive by individual-donation nucleic acid testing (ID-NAT) using the Procleix Ultrio Elite multiplex assay and again when the archived sample was retested, but the discriminatory assay for HBV was reactive. The immunocompromised recipient of the implicated red cell component was tested 110 days post-transfusion, revealing a HBV DNA viral load of 470 IU/ml. Genotype C2 sequences identical across two regions of the HBV genome were found in samples from the donor and recipient.

Blood component transfusions in mass casualty events.

BACKGROUND AND OBJECTIVES: Planning transfusion needs in mass casualty events (MCE) is critical for disaster preparedness. Published data on blood component usage were analysed to seek correlative factors and usage rates. MATERIALS AND METHODS: English-language medical publications since 1980 were searched for MCEs with numbers of patient admissions and transfused RBCs. Reports were excluded from natural disasters or with total RBC use <50 units. Statistical analysis employed Mann-Whitney U-tests and Spearman's rank correlations. RESULTS: In 24 reports, the average units per admission were 3·06 RBCs, 2·13 plasmas and 0·37 platelet doses. Five RBCs per admission would have sufficed for 87% of events. Transfusion needs involving bombings correlated with admissions (P ≤ 0·03). In the formula (massive-transfusion patients in MCE) times X = (total units for all MCE patients), the average X was 35 for RBCs (correlation P = 0·01), 17 for plasma (P = 0·10) and five for platelet doses (P = 0·06). From 67% to 84% of all components used were given in the first 24 h (event medians). CONCLUSIONS: Blood component use in MCEs correlated with numbers of patients admitted or receiving massive transfusion. More current data are needed to better reflect emerging trauma care practices and refine predictive models of transfusion needs.

Association of HLA-DRB1 and HLA-DQB1 with red-blood-cell alloimmunization in the Czech population.

BACKGROUND AND OBJECTIVES: Alloimmune antibodies against red-blood-cell (RBC) antigens induced in susceptible individuals (responders) by transfusion, pregnancy or transplantation may have serious clinical consequences. The aim of this study was to investigate association of alloimmunization against selected RBC antigens with HLA-Class II. MATERIALS AND METHODS: A total of 230 responders (106 monoresponders and 124 multiresponders) were enrolled into the study. HLA-DRB1 and HLA-DQB1 variants were determined by PCR-SSO and their frequencies compared between the patients (patient subgroups) and 375 ethnically and regionally matched controls. RESULTS: Development of multiple RBC antibodies was associated with HLA-DRB1*15 and HLA-DQB1*06 allelic groups in the patients, with the relationship being particularly apparent in those with anti-C+D antibodies. Furthermore, DRB1*13 and DQB1*06 were more frequent in multiresponders with anti-E+c antibodies and DRB1*03 and DQB1*02 in those with anti-E+Cw. CONCLUSION: For the first time, we confirmed the association of HLA-DRB1*15 with RBC antibody multiresponder status and found HLA-Class II associations for three frequent RBC antibody combinations. Our data support the concept that HLA restriction plays an important role in the response to RBC alloantigens.

Blood transfusion in preterm infants improves intestinal tissue oxygenation without alteration in blood flow.

BACKGROUND AND OBJECTIVE: The objective of the study was to investigate the splanchnic blood flow velocity and oximetry response to blood transfusion in preterm infants according to postnatal age. MATERIALS AND METHODS: Preterm infants receiving blood transfusion were recruited to three groups: 1-7 (group 1; n = 20), 8-28 (group 2; n = 21) and ≥29 days of life (group 3; n = 18). Superior mesenteric artery (SMA) peak systolic (PSV) and diastolic velocities were measured 30-60 min pre- and post-transfusion using Doppler ultrasound scan. Splanchnic tissue haemoglobin index (sTHI), tissue oxygenation index (sTOI) and fractional tissue oxygen extraction (sFTOE) were measured from 15-20 min before to post-transfusion using near-infrared spectroscopy. RESULTS: The mean pretransfusion Hb in group 1, 2 and 3 was 11, 10 and 9 g/dl, respectively. The mean (SD) pretransfusion SMA PSV in group 1, 2 and 3 was 0·63 (0·32), 0·81 (0·33) and 0·97 (0·40) m/s, respectively, and this did not change significantly following transfusion. The mean (SD) pretransfusion sTOI in group 1, 2 and 3 was 36·7 (19·3), 44·6 (10·4) and 41·3 (10·4)%, respectively. The sTHI and sTOI increased (P < 0·01), and sFTOE decreased (P < 0·01) following transfusion in all groups. On multivariate analysis, changes in SMA PSV and sTOI following blood transfusion were not associated with PDA, feeding, pretransfusion Hb and mean blood pressure. CONCLUSION: Pretransfusion baseline splanchnic tissue oximetry and blood flow velocity varied with postnatal age. Blood transfusion improved intestinal tissue oxygenation without altering mesenteric blood flow velocity irrespective of postnatal ages.