Extracorporeal photopheresis induces NETosis in neutrophils derived from patients with chronic graft-vs-host disease

INTRODUCTION

Extracorporeal photopheresis (ECP) is considered an effective treatment for patients with chronic graft vs host disease (cGVHD) and demonstrates efficacy in ameliorating GVHD. The mechanism by which ECP acts against cGVHD is not fully understood. Preliminary observations have hinted at the potential involvement of neutrophil extracellular traps (NETs) formation in the pathogenesis of cGVHD. We aimed to assess the influence of ECP on the formation of NETs in patients with cGVHD as a potential mechanism in this setting.

METHODS

Patients treated with ECP for cGVHD at the Rabin Medical Center were included in this study. Blood samples were obtained at three different time points: before starting an ECP cycle, at the end of the first day of treatment, and 24 h following the initiation of the ECP treatment cycle. Neutrophils were harvested from all blood samples. NET formation was assessed by measurement of NET-bound specific neutrophil elastase activity and by immunofluorescence staining.

RESULTS

Six patients (two females and four males) with cGVHD were included in the study. We observed a significant increase in NET formation among all six patients following ECP. Net-bound specific neutrophil elastase activity was elevated from a median value of 2.23 mU/mL (interquartile range [IQR] 2.06-2.47 mU/mL) at baseline to a median value of 13.06 mU/mL (IQR 10.27-15.97 mU/mL) immediately after the treatment and to a peak median value of 14.73 mU/mL (IQR 9.6-22.38 mU/mL) 24 h following the initiation of the ECP cycle. A qualitative assessment of NET formation using immunofluorescence staining has demonstrated markedly increased expression of citrullinated histone H3, a marker of NET formation, following ECP treatment.

CONCLUSIONS

Our preliminary data indicate that ECP induces NET formation among patients with cGVHD. The contribution of increased NET formation to the therapeutic effect of cGVHD should be further investigated.

Reciprocal interactions between innate immune cells and astrocytes facilitate neuroinflammation and brain metastasis via lipocalin-2

Brain metastasis still encompass very grim prognosis and therefore understanding the underlying mechanisms is an urgent need toward developing better therapeutic strategies. We uncover the intricate interactions between recruited innate immune cells and resident astrocytes in the brain metastatic niche that facilitate metastasis of melanoma and breast cancer. We show that granulocyte-derived lipocalin-2 (LCN2) induces inflammatory activation of astrocytes, leading to myeloid cell recruitment to the brain. LCN2 is central to inducing neuroinflammation as its genetic targeting or bone-marrow transplantation from LCN2^-/- mice was sufficient to attenuate neuroinflammation and inhibit brain metastasis. Moreover, high LCN2 levels in patient blood and brain metastases in multiple cancer types were strongly associated with disease progression and poor survival. Our findings uncover a previously unknown mechanism, establishing a central role for the reciprocal interactions between granulocytes and astrocytes in promoting brain metastasis and implicate LCN2 as a prognostic marker and potential therapeutic target.

Altered somatic hypermutation patterns in COVID-19 patients classifies disease severity

Introduction

The success of the human body in fighting SARS-CoV2 infection relies on lymphocytes and their antigen receptors. Identifying and characterizing clinically relevant receptors is of utmost importance.

Methods

We report here the application of a machine learning approach, utilizing B cell receptor repertoire sequencing data from severely and mildly infected individuals with SARS-CoV2 compared with uninfected controls.

Results

In contrast to previous studies, our approach successfully stratifies non-infected from infected individuals, as well as disease level of severity. The features that drive this classification are based on somatic hypermutation patterns, and point to alterations in the somatic hypermutation process in COVID-19 patients.

Discussion

These features may be used to build and adapt therapeutic strategies to COVID-19, in particular to quantitatively assess potential diagnostic and therapeutic antibodies. These results constitute a proof of concept for future epidemiological challenges.

International Society of Blood Transfusion Working Party on Red Cell Immunogenetics and Blood Group Terminology Report of Basel and three virtual business meetings: Update on blood group systems

BACKGROUND AND OBJECTIVES

Under the ISBT, the Working Party (WP) for Red Cell Immunogenetics and Blood Group Terminology is charged with ratifying blood group systems, antigens and alleles. This report presents the outcomes from four WP business meetings, one located in Basel in 2019 and three held as virtual meetings during the COVID-19 pandemic in 2020 and 2021.

MATERIALS AND METHODS

As in previous meetings, matters pertaining to blood group antigen nomenclature were discussed. New blood group systems and antigens were approved and named according to the serologic, genetic, biochemical and cell biological evidence presented.

RESULTS

Seven new blood group systems, KANNO (defined numerically as ISBT 037), SID (038), CTL2 (039), PEL (040), MAM (041), EMM (042) and ABCC1 (043) were ratified. Two (039 and 043) were de novo discoveries, and the remainder comprised reported antigens where the causal genes were previously unknown. A further 15 blood group antigens were added to the existing blood group systems: MNS (002), RH (004), LU (005), DI (010), SC (013), GE (020), KN (022), JMH (026) and RHAG (030).

CONCLUSION

The ISBT now recognizes 378 antigens, of which 345 are clustered within 43 blood group systems while 33 still have an unknown genetic basis. The ongoing discovery of new blood group systems and antigens underscores the diverse and complex biology of the red cell membrane. The WP continues to update the blood group antigen tables and the allele nomenclature tables. These can be found on the ISBT website (http://www.isbtweb.org/working-parties/red-cell-immunogenetics-and-blood-group-terminology/).

Long-term outcomes of catheter-based intervention for clinically significant paravalvular leak

BACKGROUND

In most centres, clinically significant percutaneous paravalvular leak (PVL) closure following valve replacement surgery is reserved for those considered high-risk for surgery. There is a paucity of data regarding the long-term outcomes of these patients.

AIMS

Our goals were to assess the long-term outcomes of patients undergoing percutaneous PVL closure.

METHODS

A total of 100 consecutive transcatheter PVL closure procedures (74 mitral, 26 aortic) were performed in 95 patients between February 2005 and August 2019 at our hospital. Data collected included procedural success rates, indication-specific outcomes and mortality.

RESULTS

Mean follow-up was 5.6±6.1 years, mean age 62.6±15.2 years, and 45.4% were female. The device was successfully implanted in 88 procedures (88.0%). Patients who presented with heart failure (n=57) had a significant improvement in NYHA classification (29.2% Class III/IV versus 100.0%, p<0.001). For patients who presented with haemolytic anaemia (n=38), haemoglobin increased (11.94±1.634 vs 9.72±1.49, p<0.001) and LDH levels were reduced (1,354.90±1,225.55 vs 2,039.40±1,347.20, p<0.001) following the procedure. Rates of mortality were 3.8% at 90 days, 15.6% after 1 year, and 27.2% after 5 years.

CONCLUSIONS

For patients who are deemed intermediate- to high-risk for repeat surgery, transcatheter PVL closure shows reasonable clinical success rates, with a significant improvement in symptoms, and a relatively low rate of periprocedural complications.

Generation of vascular chimerism within donor organs

Whole organ perfusion decellularization has been proposed as a promising method to generate non-immunogenic organs from allogeneic and xenogeneic donors. However, the ability to recellularize organ scaffolds with multiple patient-specific cells in a spatially controlled manner remains challenging. Here, we propose that replacing donor endothelial cells alone, while keeping the rest of the organ viable and functional, is more technically feasible, and may offer a significant shortcut in the efforts to engineer transplantable organs. Vascular decellularization was achieved ex vivo, under controlled machine perfusion conditions, in various rat and porcine organs, including the kidneys, liver, lungs, heart, aorta, hind limbs, and pancreas. In addition, vascular decellularization of selected organs was performed in situ, within the donor body, achieving better control over the perfusion process. Human placenta-derived endothelial progenitor cells (EPCs) were used as immunologically-acceptable human cells to repopulate the luminal surface of de-endothelialized aorta (in vitro), kidneys, lungs and hind limbs (ex vivo). This study provides evidence that artificially generating vascular chimerism is feasible and could potentially pave the way for crossing the immunological barrier to xenotransplantation, as well as reducing the immunological burden of allogeneic grafts.

Willingness and concerns of transfusion-dependent hematological patients toward the option of home transfusion therapy

BACKGROUND

One of the main obstacles of providing home-based palliative care to transfusion-dependent hematology patients is the lack of home transfusions services. While healthcare professionals are concerned with safety and cost of home transfusions, the attitude of the patients toward home transfusions are mostly unknown.

AIM

To obtain quantitative data regarding the willingness and concerns of transfusion-dependent patients with hematological diseases toward the option of home transfusions.

DESIGN

A cross sectional survey including a self-administered questionnaire in one of the three main spoken languages in Israel was administered to patients in 17 hospital hematology outpatient clinics between May 2019 and March 2020.

RESULTS

About 52% of 385 patients that participated in the survey preferred home transfusions to hospital transfusions. Gender, age, education, or type of disease were not associated with preference for home transfusions, nor were hospital location or its size. The likelihood to prefer home transfusions was significantly higher among the Hebrew-speakers and those who had not experienced adverse effects previously. The most significant factor associated with preference of home transfusions was a perceived negative effect of hospital-based transfusion on quality of life. The main reason to reject home transfusions was fear of possible adverse effects and concerns over losing contact with the medical staff at the treating hospital.

CONCLUSION

These data suggest that a significant portion of transfusion-dependent patients in Israel view home transfusions as a preferred treatment option and that its successful implementation requires maintaining ongoing contact with the treating hospital.

An Early Unexpected Immune Thrombotic Thrombocytopenic Purpura Relapse Associated with SARS-CoV-2 Infection: A Case Report and Literature Review

SARS-CoV-2 has been reported as a possible triggering factor for the development of several autoimmune diseases and inflammatory dysregulation. Here, we present a case report of a woman with a history of systemic lupus erythematosus and antiphospholipid syndrome, presenting with concurrent COVID-19 infection and immune thrombotic thrombocytopenic purpura (TTP). The patient was treated with plasma exchange, steroids, and caplacizumab with initial good response to therapy. The course of both TTP and COVID-19 disease was mild. However, after ADAMTS-13 activity was normalized, the patient experienced an early unexpected TTP relapse manifested by intravascular hemolysis with stable platelet counts requiring further treatment. Only 3 cases of COVID-19 associated TTP were reported in the literature thus far. We summarize the literature and suggest that COVID-19 could act as a trigger for TTP, with good outcomes if recognized and treated early.

[COVID-19 - BLOOD GROUPS, ANTIBODIES AND CONVALESCENT PLASMA]

Israel is currently struggling with the Coronavirus Disease (COVID-19) caused by SARS CoV-2. Transmission is increasing, with higher morbidity and mortality among populations at risk. Over-representation of blood type A was reported in COVID-19 patients with increased respiratory failure, while blood type O seems to have a protective effect. This may be caused by interference of anti-A antibodies in viral binding to the ACE receptor, different neutralization antibodies potency or variations in the stability of von Willebrand factor (VWF) multimers in different blood types. Since transfusion of convalescent COVID19 Plasma (CCP) is an accepted therapeutic modality, the Ministry of Health initiated a national project whereby CCP is collected by Magen David Adom (MDA) Blood Services using apheresis procedures and transfusions are approved by an experts committee, as part of the clinical trial or as compassionate treatment. Preliminary analysis of 49/170 patients treated so far shows improvement in 49%, with important relations with the anti-SARS-CoV-2 IgG antibodies level in the transfused plasma. Anti-SARS-CoV-2 antibodies were found in 83% of 1100 CCP donors, but a 13% decrease in antibodies level was detected in repeat donations. Blood type A was more predominant among CCP donors, when compared to MDA blood donors' data. A transfusion of CCP is a feasible and relatively safe therapeutic modality, mainly for patients with moderate COVID 19. CCP also serves as a source for the production of hyperimmune globulin for the treatment of COVID 19 and for passive immunization for populations at risk.

Red blood cell alloimmunization prevalence and hemolytic disease of the fetus and newborn in Israel: A retrospective study

Hemolytic disease of the fetus and newborn (HDFN) is a severe form of anemia caused by maternal antibodies against fetal red blood cells (RBC) that can cause intrauterine and perinatal morbidity and mortality. The prevalence and specificities of alloantibodies among Israeli pregnant women and clinical outcomes for their fetuses and newborns are unknown.

STUDY DESIGN AND METHODS

A retrospective study of women who gave birth between January 1, 2011, and December 31, 2011, was performed. Data were obtained for obstetric admissions from 16 of 27 hospitals, which included results of maternal ABO, D, antibody screens, antibody identification, and requirements for intrauterine or newborn exchange transfusions.

RESULTS

Data on 90 948 women representing 70% of all births during 2011 were analyzed. Antibody screen was positive in 5245 (5.8%) women. Alloantibodies, excluding anti-D titer (<16) were identified in 900 (1.0%) women. Of 191 D- women, 75 (39.3%) had anti-D titer of 16 or greater. Other common clinically significant antibodies were anti-E (204, 23%), anti-K (145, 16%), and anti-c (97, 10.8%) alone or in antibody combinations. Multiple alloantibodies were observed in 132 of 900 (15%) of women. Severe HDFN developed in 6.8% (9/132) of these pregnancies. Seventeen fetuses and newborns (0.02% of births) including one set of twins required RBC transfusions. Two fetuses whose mothers had multiple alloantibodies received intrauterine transfusions; one of them was hydropic and died.

CONCLUSION

The prevalence of RBC alloantibodies was 1.0% among Israeli pregnant women. Transfusion was required in 0.02% of the fetuses and newborns. Severe HDFN developed in 6.8% of pregnancies with multiple maternal alloantibodies.

Disruption of the tumour-associated EMP3 enhances erythroid proliferation and causes the MAM-negative phenotype

The clinically important MAM blood group antigen is present on haematopoietic cells of all humans except rare MAM-negative individuals. Its molecular basis is unknown. By whole-exome sequencing we identify EMP3, encoding epithelial membrane protein 3 (EMP3), as a candidate gene, then demonstrate inactivating mutations in ten known MAM-negative individuals. We show that EMP3, a purported tumour suppressor in various solid tumours, is expressed in erythroid cells. Disruption of EMP3 by CRISPR/Cas9 gene editing in an immortalised human erythroid cell line (BEL-A2) abolishes MAM expression. We find EMP3 to associate with, and stabilise, CD44 in the plasma membrane. Furthermore, cultured erythroid progenitor cells from MAM-negative individuals show markedly increased proliferation and higher reticulocyte yields, suggesting an important regulatory role for EMP3 in erythropoiesis and control of cell production. Our data establish MAM as a new blood group system and demonstrate an interaction of EMP3 with the cell surface signalling molecule CD44.

Alloimmunization and autoimmunization in adult transfusion-dependent thalassemia patients: a report from a comprehensive center in Israel

Patients with beta thalassemia major (TM) are transfusion-dependent (TD) since early childhood and for life. Development of alloantibodies and autoantibodies against red blood cell (RBC) antigens is increasingly recognized as a significant transfusion hazard, especially among heavily transfused patients. The aim of this study is to assess RBC alloimmunization and autoimmunization rates in TD TM patients treated in our Comprehensive Center of Adult Thalassemia, Hemoglobinopathies and Rare Anemias. TD TM patients, regularly transfused every 2-3 weeks, were included in the study. Clinical and RBC transfusion records, including RBC antibodies, since diagnosis in early childhood, were retrieved from patients' files and from the blood bank database. Forty TD TM patients, > 18 years of age, were included in the study. Alloimmunization was demonstrated in 17 (42.5%) patients. Thirty-four alloantibodies were detected, with the most frequent being RH related (12 of 34, 35.3%) followed by those of the Kell system (8 of 34, 23.5%). Age at first transfusion was positively related to the probability of developing alloantibodies (p = 0.02). Splenectomy was found to be correlated with developing alloantibodies (p = 0.016). Logistic regression analysis of the lifelong probability of developing alloantibodies on the age at first transfusion and splenectomy demonstrates a strong positive relationship (p = 0.002). A substantially high rate of alloimmunization was found among adult TD TM patients. Early initiation of RBC transfusions, avoidance of splenectomy and extended Rh and K antigen matching, can reduce the incidence of alloimmunization in TD TM patients.

Extended Follow-up of an Educational Intervention Encouraging Appropriate Use of Blood Transfusions

INTRODUCTION

A restrictive transfusion strategy of packed red blood cells (PRBCs) has been associated with at least non-inferior patient outcomes in a variety of clinical settings. In December 2014, we conducted an educational intervention which consisted of an oral presentation and computerized notifications at a single tertiary medical center.

OBJECTIVE

The aim of this study was to examine the long-term effects of a simple and low-cost educational intervention aimed to promote awareness to transfusion guidelines.

METHODS

We retrospectively analyzed all PRBC transfusions ordered between 2014 and 2017. The primary end point was defined as the percentage of PRBC transfused to patients with hemoglobin (Hb) ≥8 g/dL.

RESULTS

Between 2014 and 2017, a total of 27,475 PRBCs were transfused in our medical center. There was a continuous reduction in the percentage of PRBCs transfused at a Hb level ≥8 g/dL between 2014 and 2017, with a matching increase in the PRBC percentage trans-fused at Hb <7 g/dL (OR reduction of 42%, 95% CI 0.54-0.62 and OR increase of 68% [95% CI 1.56-1.81], respec-tively).

CONCLUSION

A simple educational intervention likely contributed to sustained improvement in the appropriateness of PRBC transfusions.

Prothrombin Complex Concentrate before Urgent Surgery in Patients Treated with Rivaroxaban and Apixaban

INTRODUCTION

Patients treated with direct Xa inhibitors may require urgent surgery. Administration of prothrombin complex concentrate (PCC) in this setting is common; however, it is based on limited experience in healthy volunteers.

OBJECTIVE

To characterize the population receiving PCC for apixaban/rivaroxaban reversal prior to an urgent surgery and evaluate its efficacy and safety.

METHODS

This was a retrospective study in 2 tertiary hospitals. Bleeding was evaluated based on surgical reports, hemoglobin drop, and the use of blood products or additional PCC during 48 h. Safety measures were thrombotic complications and 30-day mortality.

RESULTS

Sixty-two patients aged 80.7 ± 9 years, treated with apixaban (39.63%) or rivaroxaban (23.37%), received PCC before an urgent surgery/procedure. Most underwent abdominal operation (61%), orthopedic surgery (13%), or transhepatic cholecystostomy insertion (10%). Bleeding during surgery was reported in 3 patients (5%), no patient required additional PCC, and 16 patients (26%) received packed cells (median: 1 unit, range: 1-5). The 30-day mortality and thrombosis rates were 21% (n = 13) and 3% (n = 2), respectively. The cause of death was related to the primary disease, most commonly sepsis. No patient died due to bleeding/thrombosis.

CONCLUSIONS

Our results support the use of PCC to achieve hemostasis in patients treated with Xa inhibitors prior to an urgent surgery.

International Society of Blood Transfusion Working Party on Red Cell Immunogenetics and Blood Group Terminology: Report of the Dubai, Copenhagen and Toronto meetings

BACKGROUND AND OBJECTIVES

The International Society of Blood Transfusion (ISBT) Working Party for Red Cell Immunogenetics and Blood Group Terminology meets in association with the ISBT congress and has met three times since the last report: at the international meetings held in Dubai, United Arab Emirates, September 2016 and Toronto, Canada, June 2018; and at a regional congress in Copenhagen, Denmark, June 2017 for an interim session.

METHODS

As in previous meetings, matters pertaining to blood group antigen nomenclature and classification were discussed. New blood group antigens were approved and named according to the serologic and molecular evidence presented.

RESULTS AND CONCLUSIONS

Fifteen new blood group antigens were added to eight blood group systems. One antigen was made obsolete based on additional data. Consequently, the current total of blood group antigens recognized by the ISBT is 360, of which 322 are clustered within 36 blood groups systems. The remaining 38 antigens are currently unassigned to a known system. Clinically significant blood group antigens continue to be discovered, through serology/sequencing and/or recombinant or genomic technologies.

SMYD1 is the underlying gene for the AnWj-negative blood group phenotype

BACKGROUND

AnWj is a high-incidence blood group antigen associated with three clinical disorders: lymphoid malignancies, immunologic disorders, and autoimmune hemolytic anemia. The aim of this study was to determine the genetic basis of an inherited AnWj-negative phenotype.

METHODS

We identified a consanguineous family with two AnWj-negative siblings and 4 additional AnWj-negative individuals without known familial relationship to the index family. We performed exome sequencing in search for rare homozygous variants shared by the two AnWj-negative siblings of the index family and searched for these variants in the four non-related AnWj-negative individuals.

RESULTS

Exome sequencing revealed seven candidate genes that showed complete segregation in the index family and for which the two AnWj-negative siblings were homozygous. However, the four additional non-related AnWj-negative subjects were homozygous for only one of these variants, rs114851602 (R320Q) in the SMYD1 gene. Considering the frequency of the minor allele, the chance of randomly finding 4 consecutive such individuals is 2.56 × 10^-18 .

CONCLUSION

We present genetic and statistical evidence that the R320Q substitution in SMYD1 underlies an inherited form of the AnWj-negative blood group phenotype. The mechanism by which the mutation leads to this phenotype remains to be determined.

An international survey on the role of the hospital transfusion committee

BACKGROUND

Hospital transfusion committees (HTCs) can oversee all aspects of transfusion practice at a hospital. This survey sought to identify which quality variables were being reported at HTCs around the world.

STUDY DESIGN AND METHODS

A working party composed of members of the Biomedical Excellence for Safer Transfusion (BEST) collaborative developed a survey of quality variables that could be potentially presented at HTC meetings. The survey was electronically sent to all BEST members who were encouraged to complete it if they were active on an HTC and to send it to other colleagues with similar experience. An expert panel was convened to determine which quality variables are the most important for review at HTC meetings.

RESULTS

There were 121 respondents; the majority were from Europe (52%), Asia (19%), or North America (19%). Most respondents (68%) were at university hospitals. Of the 117 (97%) respondents with an HTC, the committee most often met quarterly (42%) and reviewed transfusion reactions (79%) and risk management-reported events (52%). The HTCs most commonly included transfusion medicine physicians, anesthesiologists, and other physicians who regularly transfuse blood products. Some of the most commonly reported quality variables included number of blood products transfused, wasted, and expired and the number of improperly labeled specimens. The expert panel analysis revealed that some variables that were deemed important were not being frequently reported at HTCs.

CONCLUSION

There is variability in the variables being reported at HTCs around the world with some important variables not frequently reported.

[DIVERSITY IN PRODUCT SELECTION AND THRESHOLDS FOR PLATELETS TRANSFUSION IN NEONATES AND PREMATURE INFANTS]

INTRODUCTION

Many premature and full-term newborns receive prophylactic platelet transfusions to prevent bleeding, particularly the most prevalent one, i.e, intracranial hemorrhages. However, the platelet count threshold above which bleeding is prevented and the efficacy of platelet transfusion in thrombocytopenic neonates, have yet to be established. Therefore, inter-Neonatal Intensive Care Units (NICU) variations in treatment indications and practices are expected. Considerable inter-NICU variations will emphasize the need for guidelines on platelet transfusions to neonates and premature infants.

AIMS

To examine platelet products selection and indications for transfusion among neonatologists in Israel. Research and Methods: Electronic questionnaires addressing the choice of platelet products and the platelet count threshold for transfusion in various clinical settings were sent to 25 neonatal units.

RESULTS

All 25 neonatal units responded (100% response rate). There was considerable variation in product selection among the different neonatal units. Up to 24% of the participating units reported selecting nontraditional products. Variation was also found in thresholds for platelet transfusion - several units used high thresholds while others used low ones. Traditional guidelines were followed in up to 64% of cases in selected clinical scenarios.

CONCLUSIONS

There is considerable variation in both platelet product selection and platelet count thresholds for transfusion among the different neonatal units.

DISCUSSION

A low threshold for platelet transfusion increases the risk for bleeding, whereas a high threshold increases the prevalence of complications from transfusion of blood products. Adherence to guidelines may prevent both such sequelae. Summary: Such variation in platelet transfusion among neonatologists emphasizes the need for an accepted policy. We recommend setting up a committee of neonatologists, pediatric hematologists and blood service experts which aims to establish an appropriate policy regarding the prevention of platelet transfusion sequelae in newborns.

International society of blood transfusion working party on red cell immunogenetics and terminology: report of the Seoul and London meetings

The Working Party has met twice since the last report: in Seoul, South Korea 2014, and in London, UK 2015, both in association with the International Society of Blood Transfusion (ISBT) Congress. As in previous meetings, matters pertaining to blood group antigen nomenclature were discussed. Eleven new blood group antigens were added to seven blood group systems. This brings the current total of blood group antigens recognized by the ISBT to 346, of which 308 are clustered within 36 blood groups systems. The remaining 38 antigens are currently unassigned to a known blood group system.

Beveled Needle Technique is Not Associated with Low Take Rates in Israeli Smallpox Revaccination Campaign

BACKGROUND

In its first large-scale smallpox vaccination campaign in the 20(th) century, Israel has experienced an exceptionally high rate of failure to achieve clinical take following vaccination. It was hypothesized that this failure rates might be attributed to the unique vaccination technique adopted in Israel, of using beveled needles rather than bifurcated needles.

MATERIALS AND METHODS

We retrospectively identified two cohorts vaccinated in the defined dates during the Israeli revaccination campaign, in which beveled needles and bifurcated needles were used alternately, and studied the impact of different covariates on clinical vaccination outcome measures.

RESULTS

Of 116 subjects that were vaccinated within the defined dates, 46 were vaccinated using bifurcated needles, and 70 by beveled needles. 'Take' rates in subjects vaccinated up to 20 years earlier was 77.5%, compared with 97.2% among those vaccinated in the more distant past (p = 0.001). In multivariate analyses, vaccination 'take' was independently associated with a shorter time from previous vaccination (p = 0.013), but not with gender, birth country, vaccinator or the vaccination technique used.

CONCLUSIONS

The low take rates observed in the Israeli smallpox revaccination campaign could not be attributed to the unique local vaccination technique, and was most likely induced by a higher rate of residual immunity among vaccinees, compared with the US, as well as by the lower vaccine concentrations used in Israel. In countries and circumstances when bifurcated needles are not sufficiently available, the beveled needle technique may be considered an appropriate alternative.

International Society of Blood Transfusion Working Party on red cell immunogenetics and blood group terminology: Cancun report (2012)

The International Society of Blood Transfusion Working Party on red cell immunogenetics and blood group terminology convened during the International congress in Cancun, July 2012. This report details the newly identified antigens in existing blood group systems and presents three new blood group systems.

Hematologic biomarkers in childhood cataracts

PURPOSE

To date, more than thirty nine genetic loci have been associated with congenital cataracts. Despite this progress, current diagnostic techniques are insufficient for unraveling the underlying genetic defect in sporadic patients and small families. In the present manuscript we demonstrate the contribution of routine laboratory tests in the search for genetic defects of childhood cataracts.

METHODS

Two families with congenital cataracts and hematologic findings that included hyperferritinemia and the "ii" blood type underwent detailed ophthalmologic and clinical examinations. Mutation analysis of the ferritin light chain (FTL) and glucosaminyl (N-acetyl) transferase 2, I-branching enzyme (GCNT2) genes was performed in the two families, respectively.

RESULTS

In the family with the "ii" blood group we found a novel GCNT2 mutation c.G935A (p.G312D) in the cataract patients, while in the family with hyperferritinemia cataract syndrome we identified a G→C heterozygous mutation at position +32 of FTL.

CONCLUSIONS

Hematologic biomarkers may simplify the search for the underlying molecular defect in families with congenital cataract.

Storage of Blood Components Does Not Decrease Haemostatic Potential: In vitro Assessment of Fresh versus Stored Blood Components Using Thromboelastography

SUMMARY: BACKGROUND: Major surgery and severe trauma typically lead to massive blood loss requiring rapid transfusion of large amounts of blood products. It has been suggested that fresh, unrefrigerated whole blood provides a haemostatic advantage in this setting. The aim of the current study was to compare the clot formation parameters of fresh, unrefrigerated whole blood and whole blood reconstituted from components stored for varying periods of time, using rotational thromboelastography (ROTEM®). METHODS: Fresh whole blood and reconstituted whole blood using combinations of non-leucoreduced red cell units (stored for 7, 14, 21, 28, or 35 days), platelet concentrates (stored for 1, 3 or 5 days), and fresh frozen plasma (stored for 6 months) were analysed using ROTEM. Measurements of the clotting time (CT), clot formation time (CFT), and maximal clot firmness (MCF) were compared between units of fresh whole blood and reconstituted whole blood samples. RESULTS: There was no difference in the haemostatic parameters measured of fresh whole blood and reconstituted whole blood using red cell units stored for less than 21 days. ROTEM demonstrated that the CT and CFT were significantly shorter for reconstituted whole blood samples using red cells stored for longer than 21 days when compared to fresh whole blood and to reconstituted whole blood samples using red cell units stored for less than 21 days. The CT was inversely correlated to the duration of platelet storage. The MCF was unchanged regardless of duration of blood product storage. CONCLUSION: Fresh unrefrigerated whole blood and blood products stored for short duration (less than 21 days) were not superior to those stored for longer durations.

Inventory management

A critical aspect of blood transfusion is the timely provision of high quality blood products. This task remains a significant challenge for many blood services and blood systems reflecting the difficulty of balancing the recruitment of sufficient donors, the optimal utilization of the donor's gift, the increasing safety related restrictions on blood donation, a growing menu of specialized blood products and an ever-growing imperative to increase the efficiency of blood product provision from a cost perspective. As our industry now faces questions about our standard practices including whether or not the age of blood has a negative impact on recipients, it is timely to take a look at our collective inventory management practices. This International Forum represents an effort to get a snap shot of inventory management practices around the world, and to understand the range of different products provided for patients. In addition to sharing current inventory management practices, this Forum is intended to foster an exchange of ideas around where we see our field moving with respect to various issues including specialty products, new technologies, and reducing recipient risk from blood transfusion products.

Epidemiology of human T-cell lymphotropic virus type 1 infection in blood donors, Israel

The prevalence of infection with human T-cell lymphotropic virus type 1 (HTLV-1) in blood donors from Israel is 1 infection/100,000 persons. In donors originating from Eastern Europe, the Middle East, and Latin America, prevalences are 7.7, 14.6, and 20.4, respectively. HTLV-1 prevalence may be high outside areas where HTLV-1 previously was known to be endemic.

Blood donors with positive direct antiglobulin tests are at increased risk for cancer

BACKGROUND

Positive direct antiglobulin tests (DATs) have been associated with both autoimmunity and lymphoproliferative disorders. However, it is unknown whether DAT+ in healthy blood donors is associated with an increased risk of malignancies.

STUDY DESIGN AND METHODS

In the current study, all blood donors with DAT+ samples were identified during the years 1999 through 2003 through the Magen David Adom National Blood Services in Israel. This study compared the risk of cancer among 586 DAT+ and 2344 DAT- donors who were matched according to sex, age, and year of donation. The risk of cancer in DAT+ donors was also compared to expected rates in the general Israeli population. Cancer was ascertained through the Israel Cancer Registry.

RESULTS

Malignancies occurred among 17 (2.9%) of the DAT+ and 27 (1.2%) of the DAT- blood donors; of these, 3 donors in the DAT+ group were diagnosed with hematopoietic malignancies within 12 months of their donation. Even after excluding these early cases, the relative risk of developing cancer was 2.14 (95% confidence interval [CI], 1.13-4.10) comparing DAT+ with DAT- donors, while the relative risk for hematopoietic cancer was 8.3 (95% CI, 1.5-43.2). Comparing DAT+ blood donors with the general population, the standardized incidence ratios (observed/expected cases) were elevated at 2.11 (95% CI, 1.15-3.54; p = 0.16) for all malignancies and 8.03 (95% CI, 2.2-20.6; p = 0.003) for hematologic malignancies.

CONCLUSION

There is evidence of a significantly increased risk of cancer, especially hematologic malignancies, among blood donors with a positive DAT even within a short follow-up period.

Genetic elucidation of human hyperosmia to isovaleric acid

The genetic basis of odorant-specific variations in human olfactory thresholds, and in particular of enhanced odorant sensitivity (hyperosmia), remains largely unknown. Olfactory receptor (OR) segregating pseudogenes, displaying both functional and nonfunctional alleles in humans, are excellent candidates to underlie these differences in olfactory sensitivity. To explore this hypothesis, we examined the association between olfactory detection threshold phenotypes of four odorants and segregating pseudogene genotypes of 43 ORs genome-wide. A strong association signal was observed between the single nucleotide polymorphism variants in OR11H7P and sensitivity to the odorant isovaleric acid. This association was largely due to the low frequency of homozygous pseudogenized genotype in individuals with specific hyperosmia to this odorant, implying a possible functional role of OR11H7P in isovaleric acid detection. This predicted receptor–ligand functional relationship was further verified using the Xenopus oocyte expression system, whereby the intact allele of OR11H7P exhibited a response to isovaleric acid. Notably, we also uncovered another mechanism affecting general olfactory acuity that manifested as a significant inter-odorant threshold concordance, resulting in an overrepresentation of individuals who were hyperosmic to several odorants. An involvement of polymorphisms in other downstream transduction genes is one possible explanation for this observation. Thus, human hyperosmia to isovaleric acid is a complex trait, contributed to by both receptor and other mechanisms in the olfactory signaling pathway.

Humans can accurately discern thousands of odors, yet there is considerable inter-individual variation in the ability to detect different odors, with individuals exhibiting low sensitivity (hyposmia), high sensitivity (hyperosmia), or even “blindness” (anosmia) to particular odors. Such differences are thought to stem from genetic differences in olfactory receptor (OR) genes, which encode proteins that initiate olfactory signaling. OR segregating pseudogenes, which have both functional and inactive alleles in the population, are excellent candidates for producing this olfactory phenotype diversity. Here, we provide evidence that a particular segregating OR gene is related to sensitivity to a sweaty odorant, isovaleric acid. We show that hypersensitivity towards this odorant is seen predominantly in individuals who carry at least one copy of the intact allele. Furthermore, we demonstrate that this hyperosmia is a complex trait, being driven by additional factors affecting general olfactory acuity. Our results highlight a functional role of segregating pseudogenes in human olfactory variability, and constitute a step towards deciphering the genetic basis of human olfactory variability.

Genetic epidemiology analysis reveals a multifaceted mechanism underlying enhanced olfactory sensitivity to the sweaty odor of isovaleric acid in humans.

Three new high-prevalence antigens in the Cromer blood group system

BACKGROUND

The Cromer blood group system consists of nine high-prevalence and three low-prevalence antigens carried on decay-accelerating factor (DAF). This report describes three new Cromer high-prevalence antigens, named ZENA, CROV, and CRAM.

STUDY DESIGN AND METHODS

Sequence analyses were performed on DNA from three probands whose serum samples each contained an alloantibody to a high-prevalence antigen in the Cromer blood group system. Polymerase chain reaction-restriction fragment length polymorphism analysis to detect the mutation encoding the CROV- phenotype was performed on 100 Croatian donors. To map the respective epitopes, DAF deletion mutants were tested by immunoblotting with eluates containing the antibodies.

RESULTS

In each proband, sequence analysis revealed a single-nucleotide substitution in DAF: ZENA, 726T>G mutation, predicted change His242Gln; CROV, 466G>A mutation, predicted change Glu156Lys; and CRAM, 740A>G mutation, predicted change Gln247Arg. By analysis of DAF deletion mutants, the CROV antigenic determinant mapped to the complement control protein (CCP) domain 2, which is encoded by exon 3, whereas ZENA and CRAM mapped to CCP4, which is encoded by exon 6.

CONCLUSION

This study describes three novel high-prevalence antigens in the Cromer blood group system each characterized by a predicted single-amino-acid substitution. The antigens have been assigned the following International Society of Blood Transfusion (ISBT) numbers: ZENA is CROM13, CROV is CROM14, and CRAM is CROM15.

Estimation of delay in detecting hepatitis C virus antibodies in pools compared to individual testing on seroconversion panels

Testing for anti-hepatitis C virus (HCV) antibodies in pools may reduce blood screening costs, making this approach affordable for developing countries, provided that the dilution of infected blood does not significantly increase the number of undetectable viral particles, especially in seroconverters. This study assessed the delay in detection of HCV antibodies in five HCV seroconversion panels, tested in pools of 6-48 samples, and estimated the risk of transfusion-transmitted HCV caused by pooling. The delay in detection of positive samples was 5-12 days for pools of all sizes, adding 7% to the risk of HCV transmission that occurs when blood donors' samples are tested individually.