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Introduction: Immunoglobulin G subclass measurements are important for the diagnostic work-up of immunodeficiencies and immunoglobulin G4 (IgG4) related diseases. It is currently unknown whether a single sampling is truly representative for an individual's IgG subclass concentrations. This study aimed to investigate whether IgG and IgG subclass concentrations in healthy individuals are stable over time. Method: With a span of median 42 weeks, four samples from each of 54 (34M, 20F) healthy adult volunteers (24–66 years) were analyzed for IgG and IgG1–4 using turbidimetry. Concentrations were compared within and between individuals. Results: IgG and IgG subclass concentrations followed either a normal (IgG, IgG1, and IgG3) or log normal (IgG2 and IgG4) distribution. Immunoglobulin 4 demonstrated by far the widest range of concentrations between individuals (670-fold: 0.004–2.68 g/L). Immunoglobulin G subclass variations within individuals were expressed as pooled standard deviations (PSD). These ranged from 0.056 (IgG4) to 0.955 g/L (IgG) and correlated with mean concentration of IgG or the particular IgG subclass. As a consequence, the relative PSDs (i.e., PSD divided by mean IgG or IgG subclass concentration) fell within a narrow range: 5.82%–10.1%. Based on these numbers, the 95%-upper one-sided confidence limits for intraindividual IgG and IgG subclass variation was calculated to range from 9.82% (IgG2) to 16.9% (IgG4). Conclusion: The study documents that IgG or IgG subclass concentrations within healthy individuals are very stable over at least 42 weeks. The expected variation for IgG4 concentrations at a 95% confidence level does not exceed ±16.9%.

The persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies is a matter of importance regarding the coronavirus disease 19 (COVID-19) pandemic. To observe antibody dynamics, 105 blood donors, positive for SARS-CoV-2 antibodies by a lateral flow test within a seroprevalence study, were included in this study. Thirty-nine (37%) of 105 the donors were confirmed positive by a total Ig Wantai enzyme-linked immunosorbent assay (ELISA). Three (8%) in this group of 39 reported severe and 26/39 (67%) mild to moderate COVID-19 symptoms. By further ELISA-testing, 33/39 (85%) donors were initially positive for IgG antibodies, 31/39 (79%) for IgA, and 32/39 (82%) for IgM, while 27/39 (69%) were positive for all three isotypes. Persistence of IgG, IgA, and IgM was observed in 73%, 79%, and 32% of donors, respectively, after 6–9 months of observation. For IgM antibodies, the decline in the proportion of positive donors was statistically significant (p = 0.002) during 12 months observation, for IgG only the decline at 3 months was statistically significant (p = 0.042). Four donors exhibited notable increases in antibody levels. In conclusion, persistent SARS-CoV-2 IgA antibodies and IgG antibodies at 6–9 months are present in approximately three of four individuals with previous mild to moderate COVID-19.

Background: Reliability of ABO-antibody measurement is important in the context of supplying low-titer ABO incompatible plasma-containing blood products. This study investigated the correlation of anti-A measurements between three different titer methodologies. Methods: Thirty-four blood group O individuals were included. IgM and IgG anti-A was measured by three different methods: (1) manual method (Bio-Rad ID-gel card), (2) automated method (Immucor NEO), (3) flow cytometry (FC) with calibration in molecules of equivalent fluorochrome (MEF). Data were log2 transformed to titer steps (TS) and log2 MEF, respectively. All three methods were benchmarked against the 14/300 WHO anti-A/anti-B standard reagent. Results: The correlation between the manual and automated methods was statistically significant for both IgM (Spearman's rs = 0.89, p s = 0.95, p 2 ≤ 0.91). With the WHO standard reagent, the manual method produced the expected results while the automated method's results were 1 TS lower for both IgM and IgG at all dilutions tested. Conclusion: These results indicate that all three methods are suitable for measuring anti-A in group O whole blood.

BACKGROUND: Increased bleeding and blood product transfusions during cardiac surgery are associated with poor outcomes. The patient's ABO blood group is related to hemostatic balance, although it is unclear whether this influences bleeding during cardiac surgery. This study aimed to evaluate whether ABO blood group is related to bleeding during cardiac surgery.METHODS: This retrospective study evaluated data from 17,058 cardiac surgical procedures that were performed in four Danish cardiosurgical centers. Data regarding chest tube drainage and transfusion volumes were retrieved from a clinical database and combined with information regarding ABO group. The primary outcome was chest tube drainage volume and the secondary outcomes were transfused volumes of various blood products.RESULTS: Blood group O had the largest chest tube drainage volume (mean: 745 mL, 95% CI: 720-771 mL) and blood group AB had the smallest volume (mean: 664 mL, 95% CI: 598-731 mL). The inter-group difference in the mean drainage volume was 81 mL (95% CI: 8-154 mL, P < .05). Patients with blood group A or blood group B had mean drainage volumes that were between the volumes for groups AB and O. Relative to group O, group AB received smaller mean volumes of all blood products. The most pronounced difference was in platelet concentrates, with mean values of 170 mL for group O (95% CI: 157-184 mL) and 63 mL for group AB (95% CI: 34-92 mL).CONCLUSION: The patient's ABO group appears to be related to volumes of chest tube drainage and transfused blood products during cardiac surgery.

Highlights • LFTs with low sensitivity are unsuited to diagnose and monitor SARS-CoV-2. • Sensitive anti-SARS-CoV-2 ELISAs are suitable for COVID-19 diagnosis in mild cases. • IgG assays with high specificity would be appropriate for seroprevalence studies., Objectives Evaluate six commercial serological assays for detection of IgA, IgM or IgG SARS-CoV-2 antibodies in different disease severities. Methods Three lateral flow tests (LFTs) (Acro IgM/IgG, CTK IgM/IgG, Livzon IgM/IgG) and three ELISA assays (Euroimmun IgA and IgG, Wantai IgM) were included. Application was evaluated in samples from 57 SARS-CoV-2 RT-PCR positive patients stratified according to disease severity. Specificity was assessed using historical samples from 200 blood donors. Results While IgM LFTs failed to detect SARS-CoV-2 antibodies in 37–84% of non-hospitalised cases, the Wantai IgM ELISA detected antibodies in 79%. The Euroimmun IgG ELISA detected antibodies in 95% of non-hospitalised subjects. IgA, IgM and IgG ELISA levels were initially low, increased over time and correlated with disease severity. LFT sensitivity declined in samples taken >28 days after symptom onset/resolution. The Livzon IgG LFT had the highest specificity (98.5%), followed by the Euroimmun IgG ELISA (96.2%). The specificity for Euroimmun IgA ELISA improved (≥97.5%) using a custom cut-off value (4.0). Conclusions The sensitive and semi-quantitative ELISA assays are most appropriate for serologic detection of SARS-CoV-2 infection in mild cases. Livzon LFT and Euroimmun ELISA had the highest specificity among the IgG assays, making them most suitable for seroprevalence studies.

Background: Reduced D antigen on red blood cells (RBCs) may be due to “partial” D phenotypes associated with loss of epitope(s) and risk for alloimmunization or “weak” D phenotypes that do not lack major epitopes with absence of clinical complications. Genotyping of samples with weak and discrepant D typing is recommended to guide transfusion and RhIG prophylaxis. The goal was to compare the impact of RHD genotyping on transfusion practice in two centers serving different populations. Study Design and Methods: Fifty-seven samples from Denmark and 353 from the United States with weak or discrepant D typing were genotyped. RBC typing was by multiple methods and reagents. DNA isolated from white blood cells was tested with RBC-Ready Gene D weak or CDE in Denmark or RHD BeadChip in the United States. RHD was sequenced for those unresolved. Results: Of Caucasian samples from Denmark, 90% (n = 51) had weak D types 1, 2, or 3; two had other weak D, two partial D, and two new alleles. In diverse ethnic U.S. samples, 44% (n = 155) had weak D types 1, 2, or 3 and 56% (n = 198) had other alleles: uncommon weak D (n = 13), weak 4.0 (n = 62), partial D (n = 107), no RHD (n = 9), and new alleles (n = 7). Conclusion: Most samples with weak or variable D typing from Denmark had alleles without risk for anti-D. In U.S. samples, 48% could safely be treated as D+, 18% may require consideration if pregnancy possible, and 34% could potentially benefit from being treated as D–. Black and multiracial ethnicities were overrepresented relative to population.

Objectives: To carry out genetic and serological analyses of a Swiss blood donor and a Danish patient carrying an aberrant ABO phenotype with weak A expression. Background: ABO is the most clinically important blood group system but also one of the most complex. The system antigens are determined by carbohydrate structures generated by A and B glycosyltransferases encoded by the ABO gene. Genetic variants of ABO may encode a glycosyltransferase with reduced activity, leading to weak expression of A antigen. Methods: Samples from two individuals were examined using genetic testing and extended immunohaematological evaluation, including standard serological methods, flow cytometry and analysis of plasma glycosyltransferase activity. Results: Both individuals were serologically determined to be AweakB. Genetic testing revealed that both were heterozygous for a novel ABO*A1.01-like allele with an in-frame duplication of 21 nucleotides in exon 7 (c.543_563dup), leading to the insertion of seven amino acids (QDVSMRR). Flow cytometric testing of native red blood cells (RBCs) showed very weak A antigen expression. This was in accordance with the enzyme activity test. Conclusion: In summary, we describe a novel A allele with a duplication of 21 nucleotides in exon 7 that significantly decreases the enzyme activity and leads to very weak expression of A antigen. (200 words).

The novel coronavirus (SARS‐Cov‐2) that was first reported in Wuhan, China and provokes the COVID‐19 disease has developed into a pandemic with hundreds of thousands of people infected. Many governments have enforced social isolation protocols on their citizens, which has led to the closure of many large public gatherings in order to limit the spread of the virus. These closures could reasonably be expected to affect blood collections, thereby presaging shortages of blood for transfusion. On the other hand, steps such as the postponement of elective surgeries and other non‐urgent transfusions could mitigate against potential shortfalls in the blood supply.

Background: There is mounting evidence that systemic uptake of food allergens is key to triggering anaphylaxis. However, direct proof for this theory is still lacking. The purpose of this study was to quantify the absorption and to determine the absorption kinetics of immunoreactive peanut protein in relation to the allergic response in human. Methods: Quantitative protein assays including mass spectrometry, dot blots and Western blotting were developed to determine the level of Ara h 2 absorption in human serum. The double monoclonal sandwich ELISA was applied to quantify absorbed Ara h 2 and 6, and the basophil histamine release assay and the human passive cutaneous anaphylaxis test were utilized to study the absorption kinetics of immunologically intact peanut proteins. Results: The protein assays worked but were not sensitive enough to trace the minute amounts of absorbed Ara h 2 in human serum. The level of Ara h 6 in serum was found to be up to 0.2 ng/mL, but Ara h 2 could not be detected with the ELISA. Both the in vivo and the in vitro methods were successful in demonstrating that: immunoreactive peanut protein was absorbed shortly after ingestion (≤5 minutes); the peanut protein concentration peaks between 1 and 4 hours; and peanut proteins can circulate for at least 48 hours in the bloodstream. Conclusion: Ingested peanut protein is absorbed systemically and retains its immunoreactive capacity in human serum. However, the precise quantities and the implication for the elicitation of anaphylaxis remains to be elucidated.

BACKGROUND Thromboelastometry (TEM) is often used to guide transfusion therapy in patients with massive bleeding. The effect of testing incompletely filled samples and those stored for a prolonged time at 4°C was investigated. METHODS Whole blood samples were collected from 15 healthy blood donors and were pooled according to ABO group. From these pools, aliquots were taken and diluted to produce final whole blood:citrate buffer ratios ranging from 90:10 (fully filled sample) to 40:60 (extremely under filled samples). These samples were then tested by EXTEM, INTEM, and FIBTEM on calibrated ROTEM delta machines. Separately, the four samples at 90:10 dilution were kept at 4°C for 16-20 hours and then retested on the ROTEM machines. RESULTS All of the samples at the 90:10 and 80:20 (half-filled sample) whole blood:citrate buffer dilutions demonstrated ROTEM parameters within their respective reference ranges, although the samples from the 80:20 dilution tended to demonstrate slightly longer or slower times, depending on each ROTEM parameter, compared to the completely filled samples. All of the samples with more dilute whole blood to citrate buffer ratios (i.e., 70:30 to 40:60) yielded abnormal TEM results. The TEM results for the 90:10 dilution samples exposed to 16-20 hours of storage at 4°C were within the reference intervals. CONCLUSION Completely and half-filled samples, and completely filled samples after prolonged cold storage, produced normal ROTEM results. Tubes that are less than half-filled should not be used for ROTEM testing.

We read with interest the International Forum recently published on Vox Sanguinis on the actions carried out from hospital transfusion services during the Coronavirus Disease 2019 (COVID‐19) [1]. The survey, to which 12 centers from around the world (included Italy) have joined, was structured on 9 questions assessing the changes in blood bank activities during COVID‐19 pandemia and including various technical aspects from pre‐transfusion testing to blood products storage and blood components utilization. Interestingly, the 9th question regarded the production of convalescent plasma (CP) [1]. The Italian participants answered that a number of protocols on CP are ongoing or planned in Italy and indicated as a reference the position paper of the Italian Society for Transfusion Medicine and Immunohematology (SIMTI) and the Italian Society for Haemapheresis and Cell Manipulation (SIdEM).

BACKGROUND Reliability of noninvasive prenatal RHD genotype test (NIP RHD) depends on having sufficient amounts of cell-free fetal DNA (cffDNA) in the maternal plasma sample. The fraction of cffDNA in maternal plasma is inversely related to maternal body mass index (BMI), suggesting that high maternal BMI may limit the test's accuracy. This study determined the effect of maternal BMI on the accuracy of NIP RHD. STUDY DESIGN AND METHODS Results from NIP RHD performed in Gestation Week 25 were correlated to maternal BMI in Week 12. The accuracy of NIP RHD result was determined by correlation with serologic RhD types of the neonates. RESULTS A total of 1618 pregnancies in 1588 D- women were included. Median BMI in these pregnancies was 24.2 (10%-90%, 20.1-32.4), and in 261 of 1618 (16%) pregnancies BMI was 30 or more (median BMI in this group was 33.6; 10th-90th percentiles, 30.5-41.1). NIP RHD was positive in 987 of 1618 (61%), negative in 582 of 1618 (36%), and inconclusive in 49 of 1618 (3.0%). Compared to the neonate's serologic RhD type, nine of 987 (0.9%) positive NIP RHD results were false positive, and four of 582 (0.7%) negative NIP RHD results were false negative (FN). In five of 49 (10%) inconclusive NIP RHD results, the neonatal RhD type was positive. There was no difference in median BMI between individuals who tested inconclusive or FN compared to those with true positive or true negative results (p = 0.80). CONCLUSION The accuracy of NIP RHD testing performed in Gestation Week 25 does not depend on maternal BMI in the 12th gestation week.

Objectives Next-generation sequencing (NGS) for the determination of rare blood group genotypes was tested in 72 individuals from different ethnicities. Background Traditional serological-based antigen detection methods, as well as genotyping based on specific single nucleotide polymorphisms (SNPs) or single nucleotide variants (SNVs), are limited to detecting only a limited number of known antigens or alleles. NGS methods do not have this limitation. Methods NGS using Ion torrent Personal Genome Machine (PGM) was performed with a customised Ampliseq panel targeting 15 different blood group systems on 72 blood donors of various ethnicities (Caucasian, Hispanic, Asian, Middle Eastern and Black). Results Blood group genotypes for 70 of 72 samples could be obtained for 15 blood group systems in one step using the NGS assay and, for common SNPs, are consistent with previously determined genotypes using commercial SNP assays. However, particularly for the Kidd, Duffy and Lutheran blood group systems, several SNVs were detected by the NGS assay that revealed additional coding information compared to other methods. Furthermore, the NGS assay allowed for the detection of genotypes related to VEL, Knops, Gerbich, Globoside, P1PK and Landsteiner-Wiener blood group systems. Conclusions The NGS assay enables a comprehensive genotype analysis of many blood group systems and is capable of detecting common and rare alleles, including alleles not currently detected by commercial assays.

Background Using potentially out-of-group blood components, like low titer A plasma and O whole blood, in the resuscitation of trauma patients is becoming increasingly popular. However, very little is known whether the donors' anti-A and/or anti-B titers change over time and whether repeated titer measurements on the same donor are required to ensure that each donation produces a low titer product. Methods The anti-A and/or anti-B titers were measured on 56 healthy adult volunteers (47 blood donors; nine blood center personnel) every 3 months for 12 consecutive months using an automated solid phase analyzer. The results were expressed as log2 titer steps (e.g., titer 32 = 5 titer steps). Results Minor variations in the average anti-A and/or anti-B titers were seen over time; the maximum individual SD in each group was 1.50 (IgG anti-A) or 1.00 (IgM anti-A, IgM, and IgG anti-B). When the SDs for the four titer measurements from all 56 volunteers were combined as appropriate, the highest overall combined SD was 0.47 titer steps for IgG anti-A. This value corresponds to a 95% confidence interval for intraindividual variation in this antibody's titer over 12 months of 0.96 titer steps. Thus, based on one measurement, an IgG anti-A with a titer step of, for example, 6 would be expected to be in the range of titer step 5 to titer step 7 over the course of 1 year with 95% probability. Conclusion The titers of anti-A and/or anti-B among healthy adults are stable over at least 1 year. This suggests that repeated titer measurements within a year on the same donor are not necessary if donations are made at 3 months or longer intervals. Level of evidence Diagnostic study, level V.

In this case report, we present a 28-year-old woman who was admitted to a neuro-intensive care unit with sub-arachnoid haemorrhage. She was intubated and haemodynamically unstable. Over five days the need for norepinephrine reached the level of 1.2 µg/kg/min to insure a sufficient cerebral perfusion pressure. Epinephrine and vasopressin were without effect in raising the blood pressure. On suspicion of tachyphylaxis the norepinephrine infusion was stopped, and no decline in blood pressure was observed. After two days without use of any vasopressor agents, the efficacy of norepinephrine returned to normal.

Background: Prior to an ABO incompatible kidney transplantation it is important to know the recipient’s pre-transplantation anti-A and/or anti-B (isoagglutinin) titer. This study determined if pre-transplantation isoagglutinin titers remained stable, over a period of 1 year, among hemodialysis patients. Method: Blood was collected four times, every 3 months from 54 hemodialysis patients (hemodialysed trice per week ≥ 6 months), and 56 healthy volunteers. Measurement of anti-A and anti-B (IgM and IgG) titers were performed on an automated solid phase analyzer. The titers were converted to log2 titer steps (e.g., titer 32 = titer step 5). Results: Within blood group O, mean IgG anti-A and anti-B titers were significantly higher in the hemodialysis patients (n = 22, mean titer step: anti-A: 6.4 and anti-B:4.9), compared to the healthy volunteers [n = 19, mean titer step: anti-A: 4.9 and anti-B:3.5, p = 0.02 (anti-A) and p = 0.03 (anti-B)], despite blood group O hemodialysis patients having significantly lower total plasma IgG levels (median 8.1 g/L) than healthy volunteers (11.1 g/L, p = 0.001). Neither age, nor gender determined IgG anti-A or anti-B titers. In hemodialysis patients and healthy volunteers, the upper 95% confidence limit of anti-A and anti-B titer variation (IgM and IgG) during 1 year, did not exceed 1.0 titer step in any of the ABO groups. Conclusions: Anti-A and -B titers (IgM and IgG) remained stable in both the hemodialysis patients and healthy volunteers over a period of approximately 1 year. Blood group O hemodialysis patients had, despite lower total IgG levels, significantly elevated IgG anti-A and -B titers.

Results from previous studies regarding platelet function in liver cirrhosis are discordant. The aim was to investigate platelet activation and platelet aggregation in patients with alcoholic liver cirrhosis. We included 27 patients with alcoholic liver cirrhosis and 22 healthy individuals. A recently established flow cytometric approach was used to measure platelet activation and platelet aggregation independent of sample platelet count. Platelet aggregation was further investigated using light transmission aggregometry (LTA) (for platelet count >100 × 109/L). Platelet agonists were adenosine diphosphate, thrombin receptor-activating peptide, arachidonic acid, collagen, and collagen-related peptide. Patients had lower median platelet count than healthy individuals, 125 × 109/L (interquartile range [IQR] 90-185) versus 240 × 109 (IQR 204-285), p < 0.001. Platelet activation levels in stimulated samples were lower in patients versus healthy individuals, e.g., after collagen-related peptide stimulation, the median percentage of platelets positive for activated glycoprotein IIb/IIIa was 85% (IQR 70-94) in patients versus 97% (IQR 94-99) in healthy individuals, p < 0.001; lower platelet activation capacity being associated with low platelet count and Child-Pugh class B/C cirrhosis. Flow cytometric platelet aggregation was reduced in patients for collagen-related peptide and for adenosine diphosphate, e.g., platelet aggregation (mean ± standard deviation) was 57% ± 4 in patients versus 70% ± 1 in healthy individuals for collagen-related peptide, p = 0.01. Light LTA showed reduced collagen-induced platelet aggregation in some patients compared with healthy individuals. In conclusion, platelet function was reduced in some patients with alcoholic liver cirrhosis and the severity was associated with platelet count and severity of liver cirrhosis. Results from previous studies regarding platelet function in liver cirrhosis are discordant. The aim was to investigate platelet activation and platelet aggregation in patients with alcoholic liver cirrhosis. We included 27 patients with alcoholic liver cirrhosis and 22 healthy individuals. A recently established flow cytometric approach was used to measure platelet activation and platelet aggregation independent of sample platelet count. Platelet aggregation was further investigated using light transmission aggregometry (LTA) (for platelet count >100 × 109/L). Platelet agonists were adenosine diphosphate, thrombin receptor-activating peptide, arachidonic acid, collagen, and collagen-related peptide. Patients had lower median platelet count than healthy individuals, 125 × 109/L (interquartile range [IQR] 90-185) versus 240 × 109 (IQR 204-285), p < 0.001. Platelet activation levels in stimulated samples were lower in patients versus healthy individuals, e.g., after collagen-related peptide stimulation, the median percentage of platelets positive for activated glycoprotein IIb/IIIa was 85% (IQR 70-94) in patients versus 97% (IQR 94-99) in healthy individuals, p < 0.001; lower platelet activation capacity being associated with low platelet count and Child-Pugh class B/C cirrhosis. Flow cytometric platelet aggregation was reduced in patients for collagen-related peptide and for adenosine diphosphate, e.g., platelet aggregation (mean ± standard deviation) was 57% ± 4 in patients versus 70% ± 1 in healthy individuals for collagen-related peptide, p = 0.01. Light LTA showed reduced collagen-induced platelet aggregation in some patients compared with healthy individuals. In conclusion, platelet function was reduced in some patients with alcoholic liver cirrhosis and the severity was associated with platelet count and severity of liver cirrhosis.

Reliability of noninvasive prenatal RHD genotype test (NIP RHD) depends on having sufficient amounts of cell-free fetal DNA (cffDNA) in the maternal plasma sample. The fraction of cffDNA in maternal plasma is inversely related to maternal body mass index (BMI), suggesting that high maternal BMI may limit the test's accuracy. This study determined the effect of maternal BMI on the accuracy of NIP RHD.Results from NIP RHD performed in Gestation Week 25 were correlated to maternal BMI in Week 12. The accuracy of NIP RHD result was determined by correlation with serologic RhD types of the neonates.A total of 1618 pregnancies in 1588 D- women were included. Median BMI in these pregnancies was 24.2 (10%-90%, 20.1-32.4), and in 261 of 1618 (16%) pregnancies BMI was 30 or more (median BMI in this group was 33.6; 10th-90th percentiles, 30.5-41.1). NIP RHD was positive in 987 of 1618 (61%), negative in 582 of 1618 (36%), and inconclusive in 49 of 1618 (3.0%). Compared to the neonate's serologic RhD type, nine of 987 (0.9%) positive NIP RHD results were false positive, and four of 582 (0.7%) negative NIP RHD results were false negative (FN). In five of 49 (10%) inconclusive NIP RHD results, the neonatal RhD type was positive. There was no difference in median BMI between individuals who tested inconclusive or FN compared to those with true positive or true negative results (p = 0.80).The accuracy of NIP RHD testing performed in Gestation Week 25 does not depend on maternal BMI in the 12th gestation week.

BACKGROUND: Transfusion of group O blood to non-O recipients, or transfusion of D- blood to D+ recipients, can result in shortages of group O or D- blood, respectively. This study investigated RBC utilization patterns at hospitals around the world and explored the context and policies that guide ABO blood group and D type selection practices.STUDY DESIGN AND METHODS: This was a retrospective study on transfusion data from the 2013 calendar year. This study included a survey component that asked about hospital RBC selection and transfusion practices and a data collection component where participants submitted information on RBC unit disposition including blood group and D type of unit and recipient. Units administered to recipients of unknown ABO or D group were excluded.RESULTS: Thirty-eight hospitals in 11 countries responded to the survey, 30 of which provided specific RBC unit disposition data. Overall, 11.1% (21,235/191,397) of group O units were transfused to non-O recipients; 22.6% (8777/38,911) of group O D- RBC units were transfused to O D+ recipients, and 43.2% (16,800/38,911) of group O D- RBC units were transfused to recipients that were not group O D-. Disposition of units and hospital transfusion policy varied within and across hospitals of different sizes, with transfusion of group O D- units to non-group O D- patients ranging from 0% to 33%.CONCLUSION: A significant proportion of group O and D- RBC units were transfused to compatible, nonidentical recipients, although the frequency of this practice varied across sites.

Essentials •Platelet function may influence bleeding risk in thrombocytopenia, but useful tests are needed. •A flow cytometric platelet aggregation test independent of the patient platelet count was made. •Platelet aggregation was reduced in thrombocytopenic patients with hematological cancer. •High platelet aggregation ruled out bleeding tendency in thrombocytopenic patients. Summary Background Methods for testing platelet aggregation in thrombocytopenia are lacking. Objective To establish a flow-cytometric test of in vitro platelet aggregation independently of the patient's platelet count, and examine the association of aggregation with a bleeding history in thrombocytopenic patients. Patients/methods We established a flow-cytometric assay of platelet aggregation, and measured samples from healthy individuals preincubated with antiplatelet drugs, and samples from two patients with inherited platelet disorders. Then, we included 19 healthy individuals and 20 patients with platelet counts of ≤ 50 × 109 L–1, diagnosed with acute myeloid leukemia or myelodysplastic syndrome. We measured platelet aggregation and platelet activation by platelet surface expression of activated glycoprotein IIb–IIIa, P-selectin and CD63 after addition of agonists: collagen-related peptide, thrombin receptor-activating peptide (TRAP), and ADP. Results The platelet aggregation assay showed a low intraserial coefficient of variation of ≤ 3%. Similar results were obtained for platelet-rich plasma and isolated platelets at platelet counts of > 10 × 109 L–1; otherwise, platelet isolation was required. The platelet aggregation percentage decreased with increasing antiplatelet drug concentration. Platelet aggregation in patients was reduced as compared with healthy individuals: 42% (interquartile range [IQR] 27–58) versus 66% (IQR 60–67) for TRAP; 41% (IQR 25–48) versus 70% (IQR 69–72) for collagen-related peptide; and 44% (IQR 30–53) versus 65% (IQR 46–72) for ADP. Platelet activation after stimulation was reduced in patients and correlated with platelet aggregation (e.g. r = 0.78–0.81 when stimulated with collagen-related peptide). Platelet aggregation had a negative predictive value of 100% for a bleeding tendency among patients. Conclusion The established platelet aggregation assay was applicable for thrombocytopenic patients, and improved the identification of bleeding risk. Essentials Platelet function may influence bleeding risk in thrombocytopenia, but useful tests are needed. A flow cytometric platelet aggregation test independent of the patient platelet count was made. Platelet aggregation was reduced in thrombocytopenic patients with hematological cancer. High platelet aggregation ruled out bleeding tendency in thrombocytopenic patients.SUMMARY: Background Methods for testing platelet aggregation in thrombocytopenia are lacking. Objective To establish a flow-cytometric test of in vitro platelet aggregation independently of the patient's platelet count, and examine the association of aggregation with a bleeding history in thrombocytopenic patients. Patients/methods We established a flow-cytometric assay of platelet aggregation, and measured samples from healthy individuals preincubated with antiplatelet drugs, and samples from two patients with inherited platelet disorders. Then, we included 19 healthy individuals and 20 patients with platelet counts of ≤ 50 × 109 L-1 , diagnosed with acute myeloid leukemia or myelodysplastic syndrome. We measured platelet aggregation and platelet activation by platelet surface expression of activated glycoprotein IIb-IIIa, P-selectin and CD63 after addition of agonists: collagen-related peptide, thrombin receptor-activating peptide (TRAP), and ADP. Results The platelet aggregation assay showed a low intraserial coefficient of variation of ≤ 3%. Similar results were obtained for platelet-rich plasma and isolated platelets at platelet counts of > 10 × 109 L-1 ; otherwise, platelet isolation was required. The platelet aggregation percentage decreased with increasing antiplatelet drug concentration. Platelet aggregation in patients was reduced as compared with healthy individuals: 42% (interquartile range [IQR] 27-58) versus 66% (IQR 60-67) for TRAP; 41% (IQR 25-48) versus 70% (IQR 69-72) for collagen-related peptide; and 44% (IQR 30-53) versus 65% (IQR 46-72) for ADP. Platelet activation after stimulation was reduced in patients and correlated with platelet aggregation (e.g. r = 0.78-0.81 when stimulated with collagen-related peptide). Platelet aggregation had a negative predictive value of 100% for a bleeding tendency among patients. Conclusion The established platelet aggregation assay was applicable for thrombocytopenic patients, and improved the identification of bleeding risk.

Background: Comparing the ABO and RhD group of a recipient's current pre-transfusion sample against their historical group is an important means of detecting wrong blood in tube (WBIT) errors. This study investigated the utility of using the donor ABO and RhD group as the historical check for recipients. Methods: A single database stores serological information on blood donors, pregnant women, and patients throughout southern Denmark. A donor ABO and RhD group can be the historical blood group should that donor later require a transfusion. This database was searched to determine how often the ABO and RhD group on a recipient's current pre-transfusion sample was discrepant with their historical donor-derived blood group. Results: During about 21 years, ABO and RhD groupings were performed on 76,455 blood donors and on 424,697 patients. There were 13,630/424,697 (3.2%) patients who had their donor-derived ABO and RhD group used as the historical comparison with the current sample; 6/13,630 (0.04%) of the current pre-transfusion samples on these patients were discrepant with the donor-derived historical group because of WBIT errors. Seven other discrepancies with the donor-derived blood group were also found. Conclusion: Accessing the donor-derived ABO and RhD group can be an important safeguard against WBIT-mediated mistransfusions.

Objective Prenatal and postnatal RhD prophylaxis reduces the risk of RhD immunization in pregnancies of RhDnegative women. Based on the result from prenatal screening for the fetal RHD gene, prenatal RhD prophylaxis in Denmark is targeted to RhD-negative women who carry an RhD-positive fetus. Here, we present a 2-year evaluation of a nationwide prenatal RHD screening. Methods Blood samples were drawn from RhD-negative women in gestational week 25. DNA was extracted from maternal plasma and analyzed for the RHD gene. The prenatal RHD results were compared with the serological typing of newborns in 12,668 pregnancies. Early compliance was assessed for 690 pregnancies. Results The sensitivity for the detection of fetal RHD was 99.9% (95% CI: 99.7–99.9%). Unnecessary recommendation of prenatal RhD prophylaxis was avoided in 97.3% of the women carrying an RhD-negative fetus. Fetuses that were seropositive for RhD were not detected in 11 pregnancies (0.087%). The sample uptake percentage was 84.2%, and the compliance for prenatal anti-D administration was 93.2%. Conclusion The high sensitivity, maintained over 2years, underlines the reliability of routine prenatal fetal RHD screening in RhD-negative pregnant women, specifically at 25weeks of gestation. The remaining challenges are logistical and are related to program compliance. © 2014 John Wiley & Sons, Ltd.

Background The RhD antigen is very immunogenic and is a significant cause of hemolytic disease of the newborn (HDN). The RHD-CE(8-9)-D hybrid allele is commonly associated with a D– phenotype. Here, we report a case of high-titer maternal anti-D and late onset of HDN in a newborn carrying a RHD-CE(9)-D variant supposedly encoding the same partial D antigen as the RHD-CE(8-9)-D allele, but with significant expression of D antigen. Study Design and Methods To elucidate the blood group antigen background of the case, we carried out serologic, flow cytometric, and genetics studies of the newborn and his father. Conclusion Individuals carrying the RHD-CE(9)-D allele do express D antigen, but do so at significantly lower levels than those carrying the more common D+ phenotypes (e.g., DCe/dce). It may mitigate and delay otherwise severe HDN in pregnancies complicated by high-titer anti-D.

OBJECTIVES: To understand the worldwide scope of RBC crossmatching and issuing practices and measure efficiency using a novel quality indicator, the crossmatch/issue (C/I) ratio.METHODS: An electronic survey was disseminated to hospital transfusion services collecting details about RBC crossmatching and issuing practices. Respondents were asked to enumerate the number of RBCs crossmatched and issued at their institutions during the 2014 calendar year to calculate the C/I ratio.RESULTS: Fifty-two survey responses were received, mostly from North American transfusion services (28/52, 54%). The electronic crossmatch was the most common technique (n = 29), and most respondents performed the crossmatch at the time that an order for RBCs was received in the transfusion service (even if an order to issue the RBCs was not received). Data to calculate the C/I ratio were supplied by 22 respondents, and the mean ± SD was 1.30 ± 0.34. There was no difference in C/I ratios between services that use the electronic or serologic crossmatch techniques (P = .49). The ratio was the same at the four sites that crossmatch RBCs at the time of issue compared with the time of order receipt (mean ± SD, 1.11 ± 0.09 vs. 1.35 ± 0.36, respectively; P = .19).CONCLUSIONS: Electronic crossmatching is common, and the C/I ratio can be an indicator of efficiency.

BACKGROUND: A combination of antenatal and postnatal RhD prophylaxis is more effective in reducing D immunization in pregnancy than postnatal RhD prophylaxis alone. Based on the result from antenatal screening for the fetal RHD gene, antenatal RhD prophylaxis in Denmark is given only to those D- women who carry a D+ fetus. We present an evaluation of the first national clinical application of antenatal RHD screening. STUDY DESIGN AND METHODS: In each of the five Danish health care regions, blood samples were drawn from D- women in Gestational Week 25. DNA was extracted from the maternal plasma and analyzed for the presence of the RHD gene by real-time polymerase chain reaction targeting two RHD exons. Prediction of the fetal RhD type was compared with serologic typing of the newborn in 2312 pregnancies, which represented the first 6 months of routine analysis. RESULTS: For the detection of fetal RHD, the sensitivity was 99.9%. The accuracy was 96.5%. The recommendation for unnecessary antenatal RhD prophylaxis for women carrying a D- fetus was correctly avoided in 862 cases (37.3%), while 39 women (1.7%) were recommended for antenatal RhD prophylaxis unnecessarily. Two RHD+ fetuses (0.087%) were not detected, and antenatal RhIG was not given. CONCLUSION: These data represent the first demonstration of the reliability of routine antenatal fetal RHD screening in D-, pregnant women to ascertain the requirement for antenatal RhD prophylaxis. Our findings should encourage the implementation of such screening programs worldwide, to reduce the unnecessary use of RhIG. P regnancy-related immunization against the red blood cell D antigen is the major cause of hemolytic disease of the fetus and the newborn (HDFN), a condition marked by fetal anemia, hydrops fetalis, jaundice, kernicterus, and intrauterine death.

The aim of the present study was to determine the weight of the normal spleen based upon a retrospective material of 539 medico-legal autopsies. Only cases above 20 years of age without indication of disease or conditions known to influence the spleen weight were included. It is found that the spleen weight is positively correlated to height, body weight and degree of acute congestion but not to sex or age. A table in which the spleen weight is correlated to height and weight is presented. The table can be used for comparison with the actual findings at an autopsy.

The RhD antigen is very immunogenic and is a significant cause of hemolytic disease of the newborn (HDN). The RHD-CE(8-9)-D hybrid allele is commonly associated with a D- phenotype. Here, we report a case of high-titer maternal anti-D and late onset of HDN in a newborn carrying a RHD-CE(9)-D variant supposedly encoding the same partial D antigen as the RHD-CE(8-9)-D allele, but with significant expression of D antigen.To elucidate the blood group antigen background of the case, we carried out serologic, flow cytometric, and genetics studies of the newborn and his father.Individuals carrying the RHD-CE(9)-D allele do express D antigen, but do so at significantly lower levels than those carrying the more common D+ phenotypes (e.g., DCe/dce). It may mitigate and delay otherwise severe HDN in pregnancies complicated by high-titer anti-D.

Prophylactic anti-D is a very safe and effective therapy for the suppression of anti-D immunization and thus prevention of haemolytic disease of the foetus and newborn. However, migration from countries with low health standards and substantial cuts in public health expenses have increased the incidence of anti-D immunization in many "developed" countries. Therefore, this forum focuses on prenatal monitoring standards and treatment strategies in pregnancies with anti-D alloimmunization. The following questions were addressed, and a response was obtained from 12 centres, mainly from Europe.

Transfusion practice is reported to differ considerably between countries. Comparisons often rely on transfusion rates, incidence - or prevalence rates. In this paper, the one-year period prevalence rate (1-YPPR) of transfusion of red cells (RBC) is presented. Transfusion data, demographic data and patient data were retrospectively combined to calculate sex and diagnosis specific and age standardized 1-YPPR s of RBC transfusion for the complete population in a Danish county. During the calendar year of 2006, 4427 patients received RBC transfusion in Funen County. The crude 1-YPPR of RBC transfusion was 9.2/1000 citizens. Most of the transfused patients had a main diagnosis of neoplasm (22% of recipients), diseases of the circulatory system (15%), the digestive system (15%), injuries (13%) and diseases of the blood (8%). Age standardization reversed the relation between sex specific 1-YPPRs, yielding a statistically significantly higher 1-YPPR in males (6.8/1000) vs. females (6.3/1000). The method for calculating a diagnosis specific 1-YPPR of transfusion of RBC is presented and proposed as an option for comparison of transfusion practice with other transfusion centres. The crude and the diagnosis specific 1-YPPR s are found to increase with age. Thus, age standardization of crude prevalence rates is necessary for meaningful comparisons between populations.

ABO-incompatible kidney transplantation is possible after pre-treatment with rituximab, intravenous immunoglobulin and basiliximab combined with tacrolimus, mycophenolate mofetil and prednisolone. We report on the first patient treated with this protocol who developed acute antibody-mediated rejection (Banff grade II with IgG deposits) caused by ABO antibodies (anti-B). Anti-rejection treatment with anti-B-specific immunoadsorption, intravenous immunoglobulin and methylprednisolone efficiently cleared deposited IgG from the kidney allograft and re-established normal kidney function. We suggest that ABO-incompatible kidney transplantation complicated by acute antibody-mediated rejection, caused by ABO antibodies, may successfully be treated with this regime.