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.

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.

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.

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.

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.

Malignant diseases and mortality in blood donors infected with human T-lymphotropic virus type 1 in Israel.

OBJECTIVES: The natural history of blood donors infected with human T-lymphotropic virus type 1 (HTLV-1) in Israel has never been assessed. The aim of this study was to evaluate the prevalence of malignant disorders and mortality among a cohort of Israelis diagnosed as HTLV-1 carriers during routine blood unit screening. METHODS: This was an observational retrospective cohort study. All HTLV-1 cases among Israeli blood donors between 1995 and 2009 were included. Data regarding malignant diseases were extracted from the Israel National Cancer Registry. Mortality data were extracted from the Israel Population Registry. RESULTS: Between January 9, 1995 and December 31, 2009, 1574497 blood donors were screened for HTLV-1 in the central blood bank services. Of these, 90 were found to be HTLV-1 carriers. This cohort of HTLV-1-infected blood donors was followed for an average of 9.2 ± 6 years. Among them six (6.7%) were diagnosed as having malignant diseases, four of them with adult T-cell leukemia/lymphoma (ATLL). The incidence of ATLL was 0.37 (95% confidence interval 0.13-1.08)/100 HTLV-1 carrier-years. CONCLUSIONS: We found a high rate of malignant diseases among HTLV-1-infected blood donors.

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.

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.

Clinical significance of serologic markers related to red blood cell autoantibodies production after red blood cell transfusion-severe autoimmune hemolytic anemia occurring after transfusion and alloimmunization: successful treatment with rituximab.

BACKGROUND: The association of autoantibody formation with blood transfusion was previously noted. Severe autoimmune hemolytic anemia (AIHA) diagnosed after red blood cell (RBC) transfusion determined us to undertake this study and investigate the incidence and clinical significance of autoantibodies occurring after transfusion by a retrospective review of blood bank and medical records. STUDY DESIGN AND METHODS: We report a lymphoma patient who developed severe autohemolysis after blood transfusion and alloantibody production. The hemolysis was refractory to steroids and chemotherapy and ceased after rituximab. We also retrospectively assessed the blood bank records for a 2-year period to identify the patients who developed autoantibodies after blood transfusion and examined laboratory, clinical features, and outcome. RESULTS: From January 2005 through December 2006, 375 direct antiglobulin tests (DATs) and 3409 indirect antiglobulin tests (IATs) were found to be positive. Thirty-eight patients with positive DATs and IATs had demonstrable RBC warm-type autoantibodies occurring after blood transfusion; 27 of them had also one or more alloantibodies. Clinical and laboratory signs of hemolysis were absent in all patients (except the case reported). In another 5 patients alloantibodies were retrieved from RBC eluate and serum without evidence of autoantibodies; therefore, a delayed serologic transfusion reaction was diagnosed. CONCLUSION: RBC autoantibodies are quite commonly found after blood transfusion. Nevertheless, clinically significant AIHA is a rare but at times a life-threatening phenomenon. We describe a first case of successful treatment with rituximab of refractory posttransfusion AIHA. Rituximab must be further evaluated for this indication.

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.

Accuracy of hepatitis C virus core antigen testing in pools among seroconverters.

BACKGROUND: Screening blood units for hepatitis C virus (HCV) with nucleic acid testing (NAT) reduces the risk associated with the long "window period" (8-9 weeks) after HCV infection. The feasibility of adding the HCV core antigen assay in pools to the existing anti-HCV individual screening was examined as an alternative of NAT, for early detection of HCV. STUDY DESIGN AND METHODS: Eighteen HCV seroconversion panels were tested for HCV antibodies, HCV antigen, and HCV RNA. Each sample was tested for HCV antigen individually and in pools of 3, 6, and 12. Statistical analyses included estimation of time until detection of the first positive HCV antigen bleed in each pool size, with a locally weighted regression (LOWESS) model. Sensitivity was calculated compared to NAT. RESULTS: Detection of HCV antigen in individual samples and in pools of 3 and 6 significantly preceded the detection of antibodies by 63, 53, and 46 days, respectively. Although the sensitivity of the HCV antigen test decreased with the increase in pool size, the estimated overall sensitivity of the "two-stage" antigen and antibody screening (where NAT of individual samples was the gold standard) was not significantly different between individual and the different pool sizes. CONCLUSION: Screening for HCV antigen in pools of 6 can be considered an efficient and easier-to-implement alternative to the costly NAT for identifying blood donors in the seroconversion period. It may offer a cost-effective approach in resource utilization in poor countries, that, after the implementation of HCV antibody testing, want to further improve blood safety.

Additional molecular bases of the clinically important p blood group phenotype.

BACKGROUND: The purpose of this study was to explore the molecular basis of the p phenotype by analysis of the recently cloned 4-alpha-galactosyltransferase gene responsible for synthesis of Pk (Gb3) antigen. STUDY DESIGN AND METHODS: Forty samples from individuals of eight different nationalities were investigated by serologic methods and DNA sequencing of the Pk gene. RESULTS: Ten different Pk-null alleles, of which 6 are novel, were encountered. The 29 Swedes were homozygous for M183K or G187D, with the former as the predominant allele. Three Israelis were homozygous for a single-nucleotide deletion at codon 219 that shifts and truncates the reading frame by 5 amino acids. Two Italians were homozygous for a triplet deletion causing F81del, while an English donor was heterozygous for F81del but also carried another allele with a combined deletion and insertion. A Pole was heterozygous for alleles with either a single-base deletion at codon 257 or a mutation causing S97L. A Norwegian person and a Japanese person were homozygous for single-base insertions causing a premature stop at codon 282 or extension of the protein by 92 residues, respectively. In 2 samples no mutations were detected. CONCLUSION: The genetic heterogeneity underlying the p phenotype is further emphasized by this study. To date, 11 p-specific mutations have been found in 14 distinct alleles.