The role of platelets and von Willebrand factor in the procoagulant phenotype of inflammatory bowel disease.

OBJECTIVE: Although the risk for thrombosis is well documented for inflammatory bowel disease (IBD) patients, the underlying pathological mechanism seems to be different from other thrombotic conditions. Deciphering the actors responsible for the increased risk of thrombosis in IBD would help to improve management of this frequent complication. DESIGN: We studied the interplay between platelets, coagulation, and von Willebrand factor (VWF) in 193 IBD patients and in experimental models (acute and chronic) of colitis in wild-type and VWF-deficient mice. RESULTS: We found a platelet-dependent increase in thrombin generation in IBD patients and in our mouse model of colitis. Agglutinated platelets were present in the blood of patients and mice. Interestingly, we observed not only a significant increase in total VWF antigen, but we were able to detect the presence of active VWF (VWF in its platelet-binding conformation; 3.2±2.7µg/ml) in the plasma of 30% of all IBD patients. In healthy controls, active VWF levels were below 0.3µg/ml. This led us to further explore experimental colitis in VWF-deficient mice and we observed that these mice were protected against the procoagulant state triggered by the colitis. Unexpectedly, these mice also manifested a significant worsening of colitis severity both in acute and chronic models. CONCLUSION: Platelets and VWF (including its active form) appear to be central players in the procoagulant phenotype in IBD. We observed that the role of VWF in hemostasis differs from its role in colic tissue healing, potentially opening new therapeutic avenues for a life-threatening complication in IBD patients.

[Triose phosphate isomerase deficiency: a rare erythrocyte enzymopathy with a poor prognosis]. / Le déficit en triose phosphate isomérase : une enzymopathie érythrocytaire rare et de pronostic sombre.

Triose phosphate isomerase (TPI) is a crucial enzyme for glycolysis. TPI deficiency is an autosomal recessive metabolic disease described in 1965, which remains exceptional by its rarity (less than 100 cases described worldwide), but by its extreme severity. Indeed, it is characterized by a chronic hemolytic anemia, an increased susceptibility to infections and especially, a progressive neurological degeneration which leads to death in early childhood for the majority of cases. We report in our observation the history of diagnosis and clinical course of monozygotic twins born at 32 WA with triose phosphate isomerase deficiency.

A Serious Game About Hematology for Health Care Workers (SUPER HEMO): Development and Validation Study.

BACKGROUND: Complete blood count (CBC) and hemostatic screening tests are among the most commonly prescribed blood tests worldwide. All health care workers (nurse practitioners, pharmacists, dentists, midwives, and physicians) are expected to correctly interpret the results in their daily practice. Currently, the undergraduate hematology curriculum consists predominantly of lecture-based teaching. Because hematology combines basic science (blood cells and hemostasis physiology) and clinical skills, students report that they do not easily master hematology with only lecture-based teaching. Having interviewed students at the University of Lorraine, we considered it necessary to develop new teaching approaches and methods. OBJECTIVE: We aimed to develop and validate a serious game about CBC analysis for health care students. Our primary objective was to help students perceive hematology as being a playful and easy topic and for them to feel truly involved in taking care of their patients by analyzing blood tests. We considered that this game-based approach would be attractive to students as an addition to the classic lecture-based approach and improve their knowledge and skills in hematology. METHODS: We developed an adventure game called SUPER HEMO, a video game in which the player assumes the role of a protagonist in an interactive story driven by exploration and problem-solving tests. Following validation with beta testing by a panel of volunteer students, we used a novel, integrated teaching approach. We added 1.5 hours of gaming to the standard curriculum for a small group of volunteer students. Physician and pharmacy students in their third year at a single French university were invited to attend this extracurricular course. Pregame and postgame tests and satisfaction surveys were immediately recorded. Final hematology exam results were analyzed. RESULTS: A total of 86 of 324 physician students (26.5%) and 67 of 115 pharmacy students (58%) opted to participate. Median scores on the pre- and posttests were 6 out of 10 versus 7 out of 10, respectively, for the physician students, (P<.001) and 7.5 out of 10 versus 8 out of 10, respectively, for the pharmacy students (P<.001). At the final hematology evaluation, physician students who played SUPER HEMO had a slightly better median score than those who did not: 13 out of 20 versus 12 out of 20, respectively (P=.002). Pharmacy students who played SUPER HEMO had a median score of 21.75 out of 30; this was not significantly different from pharmacy students who did not play SUPER HEMO (20/30; P=.12). Among the participants who answered the survey (n=143), more than 86% (123/143) believed they had strengthened their knowledge and nearly 80% (114/143) of them had fun. CONCLUSIONS: Feedback from this game session provided evidence to support the integration of interactive teaching methods in undergraduate hematology teaching. The development of SUPER HEMO is intended to be completed so that it can become a support tool for continuing education.

Binge drinking alongside alcoholic chronic abuse.

Here is reported the case of an adult patient with ethylic cirrhosis associated with spur cell anemia. Moreover, acute vacuolation of leukocytes was observed in relationship with recent binge drinking.

Optimizing the management of analytical interferences affecting red blood cells on XN-10 (Sysmex®).

INTRODUCTION: Interferences on red blood cells (RBCs) measurement and the associated parameters in haematology analyzers are very common. Many sources of interferences are described but their management remains uncertain depending on the measurement system; we aimed at developing an optimized scheme allowing the accurate management of most interferences affecting RBCs, based on the alternative "optical" parameters from SYSMEX XN-10. METHODS: Samples from 12 groups of relevant interferences were analysed and compared with a control group allowing (1) the determination of deviation thresholds beyond which an interference is likely, and (2) the development of two flowcharts for their subsequent management. These flowcharts were then evaluated among a bank of retrospective typical cases of interferences and in the routine flow of the laboratory. RESULTS: After verifying the excellent agreement between standard and alternative parameters, the comparative study between analytical channels allowed to determine an acceptable deviation and then discriminate technical concerns caused by cold agglutinins, leukocytosis and plasma-related interferences. This led to the development of flowcharts ensuring the accurate management of these interferences, whether MCHC is <320 or >365 g/L. These proposed flowcharts allowed the correction of 63/65 historical confirmed interferences cases (97%). Furthermore, they corrected 18 results among 901 unselected prospective samples. CONCLUSION: The resulting flowcharts allow a relevant correction for most common interferences affecting RBCs and are now definitively included in the routine analytical management and will be directly incorporated in the middleware of the laboratory.

Heparin-induced thrombocytopenia: Construction of a pretest diagnostic score derived from the analysis of a prospective multinational database, with internal validation.

BACKGROUND: Diagnosis of heparin-induced thrombocytopenia (HIT) requires pretest probability assessment and dedicated laboratory assays. OBJECTIVE: To develop a pretest score for HIT. DESIGN: Observational; analysis of prospectively collected data of hospitalized patients suspected with HIT (ClinicalTrials.gov NCT00748839). SETTING: Thirty-one tertiary hospitals in France, Switzerland, and Belgium. PATIENTS: Patients tested for HIT antibodies (2280 evaluable), randomly allocated to derivation and validation cohorts. MEASUREMENTS: Independent adjudicators diagnosed HIT based on the prospectively collected data and serotonin release assay results. RESULTS: Heparin-induced thrombocytopenia was diagnosed in 234 (14.7%) and 99 (14.5%) patients in the two cohorts. Eight features were associated with HIT (in brackets, points assigned for score calculation of the score): unfractionated heparin (1); therapeutic-dose heparin (1); cardiopulmonary bypass (cardiac surgery) (2); major trauma (3); 5- to 21-day interval from anticoagulation initiation to suspicion of HIT (4); ≥40% decrease in platelet count over ≤6 days (3); thrombotic event, arterial (3) or venous (3). The C-statistic was 0.79 (95% CI, 0.76-0.82). In the validation cohort, the area under the receiver operating characteristic curve was 0.77 (95% CI, 0.74-0.80). Three groups of scores were defined; HIT prevalence reached almost 30% in the high-probability group. LIMITATION: The performance of the score may depend on settings and practices. CONCLUSION: The objective, easy-to-collect, clinical features of HIT we evidenced were incorporated into a pretest score, which may guide clinical decisions regarding diagnostic testing and anticoagulation.

Study of thrombin generation with St Genesia to evaluate xaban pharmacodynamics: Analytical performances over 18 months.

INTRODUCTION: ST Genesia is a new automated system enabling quantitative standardized evaluation of thrombin generation (TG), for example, in patients receiving anti-Xa direct inhibitors (xabans). Data on its analytical performances are scarce. METHODS: Over an 18-month period, repeatability, reproducibility, and accuracy were assessed using STG-ThromboScreen (without or with thrombomodulin) or STG-DrugScreen reagents (corresponding to intermediate/high tissue-factor concentration, respectively), and controls. Furthermore, reproducibility was assessed using commercialized lyophilized and frozen normal pooled plasmas. Rivaroxaban and apixaban impacts on TG parameters were assessed using spiking experiments. Finally, a comparison with the Calibrated Automated Thrombogram method (CAT) (PPP reagent) was performed using plasma from healthy volunteers enrolled in the DRIVING-studyNCT01627665) before and after rivaroxaban intake. RESULTS: For all dedicated quality control (QC) levels, inter-series coefficients of variations (CV) were <7% for temporal TG parameters, peak height (PH), and endogenous thrombin potential (ETP), whether results were normalized with a dedicated reference plasma STG-RefPlasma or not. Noteworthy, STG-RefPlasma used for normalization displayed substantially high PH and ETP. Mean biases between the observed and manufacturer's assigned QC values were mostly <7%. Both rivaroxaban/apixaban plasma concentrations were significantly associated with TG parameters. Finally, Bland-Altman plots showed a good agreement between ST Genesia-STG-ThromboScreen and CAT method within the explored range of values, although biases could be observed (PH: 16.4 ± 13.2%, ETP: 17.8 ± 11.9%). CONCLUSION: ST Genesia® enables the reliable measurement of TG parameters in both in vitro and ex vivo xaban plasma samples using either STG-ThromboScreen or STG-DrugScreen according to xaban concentrations. The use of reference plasma, despite not completely reflecting a normal pooled plasma behavior, likely improves standardization and inter-laboratory comparisons.

Comparative Analysis of a French Prospective Series of 144 Patients with Heparin-Induced Thrombocytopenia (FRIGTIH) and the Literature.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is a rare complication of heparin treatments, and only a few large patient cohorts have been reported. In this study, biological and clinical data from 144 French patients with HIT were analyzed in comparison with the literature. METHODS: The diagnosis of HIT was confirmed in all patients by an immunoassay combined with serotonin release assay. In the literature, only cohorts of at least 20 HIT patients published from 1992 were selected for a comparative analysis. RESULTS: Two-thirds of patients were hospitalized in surgery and most were treated with unfractionated heparin (83.2% vs. 16.8% with low molecular weight heparin only). Thrombotic events in 54 patients (39.7%) were mainly venous (41/54). However, arterial thrombosis was more frequent after cardiac surgery (13.2% vs. 2.4% in other surgeries, p = 0.042) with a shorter recovery time (median = 3 vs. 5 days, p < 0.001). The mortality rate was lower in our series than in the 22 selected published studies (median = 6.3% vs. 15.9%). Three genetic polymorphisms were also studied and homozygous subjects FcγRIIA RR were more frequent in patients with thrombosis (37.8 vs. 18.2% in those without thrombosis, p = 0.03). CONCLUSION: This study shows that the mortality rate due to HIT has recently decreased in France, possibly due to earlier diagnosis and improved medical care. It also confirms the strong association between polymorphism FcγRIIA H131R and thrombosis in HIT.

[Hyperthyroidism: acquired cause of an increase in haemoglobin A2 level]. / Hyperthyroïdie : cause acquise d'augmentation de l'hémoglobine A2.

Hyperthyroidism may be associated with several haematological disorders, including an increase in haemoglobin A2 level. We report the case of haemoglobin study in a 29-years old man of Mediterranean origin presenting microcytosis. Results showed a slight increase in haemoglobin A2 level, suggestive of a beta-thalassemia trait, which was finally related to the existence of a recently diagnosed Grave's disease.

Erythrocytes morphology in pregnancy.

Morphologic anomalies of the red blood cells (RBCs) during pregnancy are poorly known. Peripheral blood films from 69 healthy pregnant women were investigated for shape, color and content anomalies of the RBCs. A range of minor alterations was observed, without clinical significance. Only a slight increase of polychromatophilic RBCs was regularly observed. However, we would like to stress that spherocytes or schistocytes can occasionally be found, even in the absence of hemolysis.

Clinical and biological features in PIEZO1-hereditary xerocytosis and Gardos channelopathy: a retrospective series of 126 patients.

We describe the clinical, hematologic and genetic characteristics of a retrospective series of 126 subjects from 64 families with hereditary xerocytosis. Twelve patients from six families carried a KCNN4 mutation, five had the recurrent p.Arg352His mutation and one had a new deletion at the exon 7-intron 7 junction. Forty-nine families carried a PIEZO1 mutation, which was a known recurrent mutation in only one-third of the cases and private sequence variation in others; 12 new probably pathogenic missense mutations were identified. The two dominant features leading to diagnosis were hemolysis that persisted after splenectomy and hyperferritinemia, with an inconstant correlation with liver iron content assessed by magnetic resonance imaging. PIEZO1-hereditary xerocytosis was characterized by compensated hemolysis in most cases, perinatal edema of heterogeneous severity in more than 20% of families and a major risk of post-splenectomy thrombotic events, including a high frequency of portal thrombosis. In KCNN4-related disease, the main symptoms were more severe anemia, hemolysis and iron overload, with no clear sign of red cell dehydration; therefore, this disorder would be better described as a 'Gardos channelopathy'. These data on the largest series to date indicate that PIEZO1-hereditary xerocytosis and Gardos channelopathy are not the same disease although they share hemolysis, a high rate of iron overload and inefficient splenectomy. They demonstrate the high variability in clinical expression as well as genetic bases of PIEZO1-hereditary xerocytosis. These results will help to improve the diagnosis of hereditary xerocytosis and to provide recommendations on the clinical management in terms of splenectomy, iron overload and pregnancy follow-up.

An usual cause of elliptocytosis.

We report a 60-year-old adult case with a normocytic normochromic regenerative anemia discovered incidentally. The objectification of elliptocytosis accompanied by splenomegaly, a collagen myelofibrosis and the presence of the mutation JAK2V617F allowed the diagnosis of primary myelofibrosis with atypical initial presentation. The causes of elliptocytoses are discussed.