Concordance between platelet counts by impedance and optical technique during microcytic anemia: towards a threshold value of the mean corpuscular volume.

INTRODUCTION: Platelet count is crucial for clinical decision. In cases of microcytosis, platelet count based on impedance technique (PLT-I) may overestimate platelet count. AIM: To compare PLT-I with platelet count using the optical technique (PLT-O) and establish a Mean Corpuscular Volume (MCV) threshold for considering PLT-O. METHODS: A prospective analytical study conducted over two months involved blood samples collected in standard K2 EDTA tubes for complete blood count analysis, revealing microcytosis (MCV<80 fL). PLT-O analysis in channel-Ret mode was performed using the Sysmex-XN1000 (Sysmex Corporation, Kobe, Japan). Percentage of fragmented red cells (FRC%) and percentage of microcytic red cells (Micro-R%) were recorded. Blood smears stained with May-Grünwald-Giemsa were examined for potential interfering particles. RESULTS: A strong correlation was observed between the two techniques for all platelet values as well as for PLT <150 x 109/L (correlation coefficient r = 0.971, 95% CI: [0.956-0.982]; P<10-3 and r = 0.90, 95% CI: [0.79-0.95]; P< 10-3). The Bland-Altman plot revealed a bias of 16.53 x 109/L between the two methods, with agreement limits between -55.8 and 88.8 x 109/L. A threshold MCV value indicating the use of the optical method, with a cut-off at 72.9fL, demonstrated promising performance consistent with literature findings. However, less favorable performance was observed with Micro-R%. CONCLUSION: Impedance could be employed in routine practice. However, for MCV<72.9 fL or in the presence of schizocytes, the hemogram validation procedure may incorporate the use of PLT-O.

ImpaCt of aspirin regimen on THrombin generation in diabEtic patients with acute coronary syndrome: CARTHaGE-ACS trial.

BACKGROUND: Diabetes is associated with a high rate of events after acute coronary syndrome. It was recently reported that once-daily aspirin might not provide stable biological efficacy in patients with diabetes. AIMS: We sought to compare the biological efficacy of aspirin given once a day versus aspirin divided twice per day in a population of diabetic patients with non-ST elevation acute coronary syndrome (NSTE-ACS) as assessed by the thrombin generation test. METHODS: We performed an open-label single-blind randomized study including 59 consecutive diabetic patients admitted for NSTE-ACS. Patients were randomly treated with aspirin 100 mg once a day (GA100; n = 20), aspirin 160 mg once a day (GA160; n = 19) or aspirin 100 mg twice a day (G2A100; n = 20). The primary endpoint was endogenous thrombin potential (ETP) at discharge and after 6 months. RESULTS: The mean age of our patients was 61.5 ± 9 years, and 73% were male. The baseline characteristics were comparable between the three groups. In the GA100 group, there was no significant effect on ETP variation at 6 months (1150.46 ± 504.84 vs. 1087.63 ± 454.18; p = 0.794). An increase in aspirin dose with a second daily administration of 100 mg was associated with a significant reduction in ETP at 6 months (1004.87 ± 196.2 vs. 1233.63 ± 333.5; p = 0.003). A nonsignificant decrease in ETP was seen in the GA160 group (from 1173.8 ± 388.07 to 1053.64 ± 269.93 at 6 months, p = 0.117). CONCLUSION: Only the twice-daily aspirin regimen led to better control of hypercoagulability in NSTE-ACS diabetic patients. However, no thrombin generation normalization was reported.

The hypercoagulable state in multiple myeloma: The contribution of thrombin generation test.

BACKGROUND: Multiple myeloma is a hematologic malignancy which confers a high venous thromboembolic risk. This risk is linked to patient-related factors, disease-specific mechanisms, and antimyeloma therapy, especially immunomodulatory drugs. Some studies have suggested that the thrombin generation assay may be a predictive marker of thrombosis. This study aimed to assess the hypercoagulable state in patients with multiple myeloma at diagnosis and after myeloma therapy. METHODS: Thirty-one patients with multiple myeloma were included in a prospective study and were compared with 31 matched controls with age and gender. Thrombin generation assay was performed in patients at diagnosis prior to treatment initiation and at the end of myeloma therapy, and in controls. Parameters of lag time, peak thrombin concentration, time to peak, endogenous thrombin potential, and velocity index were analyzed. RESULTS: Median age of patients at diagnosis was 58 years (11 men and 20 women). Twenty-three patients (74%) were classified as high vascular risk and received thromboprophylaxis. No thromboembolic events have been reported during follow-up, except a symptomatic pulmonary embolism in one patient which occurred at diagnosis. At baseline, patients with myeloma had significantly elevated velocity index as compared to controls (178 vs 128 nmol/L/min; P = .013). High-risk patients showed an elevation of plasma thrombin generation as compared to low-risk patients (endogenous thrombin potential = 1244 vs 1052 nmol/L/min; P = .043). Myeloma therapy did not significantly change the thrombin generation parameters. CONCLUSION: Thrombin generation appears to be higher in patients with myeloma compared with controls, especially in high-risk patients, and does not change significantly after treatment completion.

The relationship between coagulation disorders and the risk of bleeding in cirrhotic patients.

INTRODUCTION AND OBJECTIVES: For long, bleeding in cirrhotic patients has been associated with acquired coagulation disorders. The aim of our study was to investigate the impact of acquired coagulation disorders on bleeding risk in cirrhotic patients. MATERIALS AND METHODS: Blood samples were collected from 51 cirrhotic patients with (H+) or without (H-) bleeding events and 50 controls matched by age and sex. Thrombin generation was assessed as endogenous thrombin potential (ETP). Hemostatic balance was assessed by means of ratios of pro- to anticoagulant factors and by ETP ratio with/without protein C (PC) activator (ETP ratio). RESULTS: Bleeding events occurred in 9 patients (17.6%). Compared with controls, VIII/anticoagulant factors, VII/PC and XII/PC were significantly higher in (H+) patients. No significant difference as regards all ratios across patient groups was detected. ETP ratio was significantly higher in (H+) patients than in controls (p=0.017). However, there was no significant difference between patient groups as regards ETP ratio. CONCLUSION: Hemostatic balance is shifted toward a hypercoagulability state even in cirrhotic patients who experienced bleeding. These findings provide evidence against traditional concept of hemostasis-related bleeding tendency in cirrhotic patients.

Cerebral Venous Thrombosis: A Tunisian Monocenter Study on 160 Patients.

OBJECTIVE: Data regarding cerebral venous thrombosis in North Africa are scarce. This study aims to identify the clinical features, risk factors, outcome, and prognosis of cerebral venous thrombosis in Tunisia. METHODS: Data of 160 patients with radiologically confirmed cerebral venous thrombosis, hospitalized in Mongi Ben Hmida National Institute of Neurology (Tunis, Tunisia), were retrospectively collected and analyzed. RESULTS: The mean age was 37.3 years with a female predominance (83.1%). The mode of onset was subacute in most cases (56.2%). Headache was the most common symptom (71.3%), and focal neurologic symptoms were the main clinical presentation (41.8%). The most common sites of thrombosis were the superior sagittal sinus (65%) and the lateral sinus (60.6%). More than 1 sinus was involved in 114 (71.2%) patients. Parenchymal lesions observed in 85 (53.1%) patients did not correlate with cerebral venous thrombosis extent. Major risk factors were obstetric causes (pregnancy and puerperium) found in 46 (38.6% of women aged <50 years) patients, followed by anemia (28.1%) and congenital or acquired thrombophilia (16.2%). Mortality rate was of 6.6%. Good outcome at 6 months (modified Rankin Scale ≤2) was observed in 105 (87.5%)of 120 patients available for follow-up. Predictors of poor outcome were altered consciousness and elevated plasma C-reactive protein levels. CONCLUSION: Clinical and radiologic presentation of cerebral venous thrombosis in Tunisia was quite similar to other parts of the world with, however, a particularly high frequency of obstetric causes. Plasma C-reactive protein level should be considered as a prognostic factor in CVT.

Haemostatic balance in cirrhosis.

Despite the prolongation of coagulation tests, recent studies reported an increased frequency of thromboembolic events in patients with cirrhosis. The aim of this study was to evaluate the haemostatic balance in cirrhotic patients through assessing the variation of pro- and anticoagulant factors and evaluating the in-vitro thrombin generation in patients with cirrhosis and in healthy patients. Fifty-one cirrhotic patients with or without thromboembolic events and 50 controls matched by age and sex were enrolled. Procoagulant (factors VII, II, V, VIII, and XII) and inhibitor (protein C, protein S and antithrombin) factor activities were determined. Thrombin generation was measured as endogenous thrombin potential (ETP). Haemostatic balance was assessed by means of both procoagulant to inhibitor coagulation factor ratios and ETP with to without protein C activation ratios. There were 24 males and 27 females. The mean age was 57.8 years [16-91 years]. Pro and anticoagulant factors were significantly lower in patients than in controls (P < 0.001) except for factor VIII and protein S. In fact factor VIII level was significantly higher in patients than in controls and protein S levels were not significantly different between patients and controls. Almost all the pro to anticoagulant factor ratios were higher in cirrhotics than in controls, especially the factor VIII to protein C ratios which increased significantly from Child Pugh A to C (P < 0.001), the ratio of ETP with to without protein C activator was higher in patients than in controls, but did not reach a significant level (0.8 vs. 0.52) There was no statistically significant difference between Child classes. When comparing patients with history of thrombosis (n = 7) to those matched by age and sex and without history of thrombosis (n = 14), the ratios were not statistically different between the two groups. Haemostatic changes in cirrhosis tend to rebalance the haemostatic system. This state often results in a hypercoagulable state attested by increased pro- to anticoagulant factor ratios and a normal thrombin generation.

Extracorporeal lithotripsy in patients with hemophilia: systematic review.

BACKGROUND: The management of urolithiasis in patients with haemophilia poses a real challenge to the urologist. AIM: We conducted a systematic literature review to assess the safety and efficacy of extracorporeal shock wave lithotripsy (ESWL) in the treatment of urolithiasis in hemophiliacs. METHODS: A systematic review was conducted by using the National Library of Medicine (PubMed) search engine between January 1985 and June 2013. We've used these key words: "haemophilia" and "extracorporeal shock wave lithotripsy". All articles dealing with the treatment of nephrolithiasis by ESWL in patients with hemophilia were included. Two independent reviewers extracted the data from each article. The data was included into a systematic review and analyzed. RESULTS: A total of 12 medical articles were selected with a total of 25 patients. The stone size varies from 6 to 21 mm. The substitution of the deficient clotting factor started the day before the ESWL. ESWL was effective in all patients except one after 1-6 sessions / patient. An ultrasound was performed after the procedure to look for potential bleeding complications. The judgment of the substitution therapy depends on the patient's condition, the presence of hematuria and the absence of signs of bleeding. Major bleeding complications were observed in 4 patients. CONCLUSIONS: With effective substitution of deficient clotting factors, ESWL is a safe and low morbidity method in the treatment of urinary calculi in hemophiliacs.

[The JAK2 mutation in myeloproliferative disorders: A predictive factor of thrombosis]. / La mutation JAK2 dans les syndromes myéloprolifératifs BCR-ABL négatifs: facteur prédictif de thrombose.

BACKGROUND: BCR-ABL negative myeloproliferative neoplasms (MPN) include polycythemia Vera (PV), essential thrombocythemia (ET) and primitive myelofibrosis (PMF). the JAK2 V617F mutation has been introduced since 2008 as a major diagnostic criterion on the one hand and on the other hand, it would be linked to increased risk of thrombotic complications. AIM: This study aimed to evaluate the association of JAK2 mutation and thrombotic events in MPN. METHODS: A retrospective study concerning 45 BCR-ABL negative MPN patients (mean age=53 old years, sex ratio=0.8) was conducted. RESULTS: They were classified as PV (22 patients), ET (17 patients), PMF (3 patients) and atypical MPN (3 patients). The JAK2 mutation was found in 64.4% of patients: 72.7% of PV patients, 47% of ET patients and 66.7% of PMF patients. Thrombotic events were recorded in 11 patients (24.4%). Cerebral arteries and portal vein were the most frequent localizations. The JAK2 mutation was an independent risk factor of thrombotic events. CONCLUSION: Consequently, it seems that screening for JAK2 mutation in BCR-ABL negative MPN could play a role in identifying patients at high risk of vascular complications.

[Transfusion safety: state of the arts (ART)]. / Sécurité transfusionnelle: etat des lieux.

BACKGROUND: Blood transfusion is a high risk activity. AIM: To evaluate transfusion safety in planned cardiac surgery. METHODS: This study was conducted in the blood bank of the Rabta Hospital in two phases: a phase to observe transfusion acts followed by corrective actions and a phase to evaluate the impacts of these corrections on the transfusion practices. Characteristics of the potentially transfused patients, the eventually prescribed, dispensed and transfused blood products and transfusion practices were studied. RESULTS: During the observation phase, 70 patients were enrolled, 51 potentially transfused. Weaknesses concerned the mention of phenotype and transfusion history when ordering blood components as well as the double ABO/D group typing, the phenotype and the cross match performing. Final bedside controls were done in a wrong way. The distribution and the blood administration were established respectively for 208 and 232 blood products. The traceability was established for 86 blood products. During the evaluation phase, 30 patients were enrolled, 15 potentially transfused. Improvement was achieved in the transfusion history notification, phenotype and antibodies screen performing and cross matching. CONCLUSION: Optimisation of blood transfusion can be conceived only with collaboration between the different transfusion structures.

[Protein S, C and antithrombin deficiency: association with myocardial infarction and thromboembolism in the young]. / Déficits en protéine S, C et antithrombine: Association à l'infarctus du myocarde et aux évènements thrombo-emboliques chez le sujet jeune.

BACKGROUND: The pathogenesis of myocardial infarction (MI) in young involves new factors including constitutional or acquired thrombophilia. AIM: To determine in patients ² 50 years, the association between coagulation factors deficiency, myocardial infarction and cardiovascular events during follow-up. METHODS: Protein C (PC), PS and antithrombin (AT) were screened in 50 patients admitted for acute MI and in a healthy control group. Univariate and multivariate analysis were performed using SPSS 11.5 version. RESULTS: PS and PC deficiency were associated to MI (respectively 24% vs 0%, p=0.001 and 14% vs 0%, p=0.016), independently for PC. No AT deficiency was detected in both groups. During followup, PS and C deficiency were predictive for venous thrombosis (p<0.05) and PS deficiency for pulmonary embolism. CONCLUSION: Protein C and S deficiency may play an important role in MI in young and also in thromboembolic complications during follow-up. Nevertheless, therapeutic implications remain controversial.

Description of response to aspirin and clopidogrel in outpatients with coronary artery disease using multiple electrode impedance aggregometry.

Identification of outpatients with high platelet reactivity (HPR) on antiplatelet treatment is an unmet need. The present study was conducted in healthy individuals (n = 50) and in outpatients with coronary artery disease (CAD) at a distance from the acute ischemic episode (aspirin group, n = 71; aspirin/clopidogrel group, n = 106). We studied the feasibility and the precision of whole blood multiple electrode aggregometry (MEA) after triggering platelet aggregation by arachidonic acid or adenosine diphospate (ADP). The MEA can be performed on whole blood within 2 hours after sample venipuncture. The threshold for the diagnosis of HPR is situated at 55 and 50 U for the arachidonic acid and ADP test, respectively. Frequency of HPR was 7% and 20% in aspirin and aspirin/clopidogrel groups, respectively. In 3.8% of patients in aspirin/clopidogrel group, combined HPR on aspirin and clopidogrel was found. In outpatients with CAD, use of MEA is feasible for the diagnosis of HPR.

Tissue factor over-expression by human pancreatic cancer cells BXPC3 is related to higher prothrombotic potential as compared to breast cancer cells MCF7.

Cancer histology influences the risk of venous thromboembolism and tissue factor (TF) is the key molecule in cancer-induced hypercoagulability. We investigated the relation between TF expression by pancreatic and breast cancer cells (BXPC3 and MCF7 respectively) and their capacity to trigger in vitro thrombin generation in normal human plasma. Flow cytometry and Western blot analysis for TF expression were performed using murine IgG1 monoclonal antibody against human TF. Real-time PCR for TFmRNA was also performed. Activity of TF expressed by cancer cells was measured with a specific chromogenic assay. Thrombin generation in PPP was assessed using calibrated automated thrombogram. Cancer cells were added to platelet poor plasma from healthy volunteers. In separate experiments cells were incubated with the anti-TF antibody at concentration that completely neutralized the activity of recombinant human TF on thrombin generation. BXPC3 cells expressed significantly higher amounts of functional TF as compared to MCF7 cells. Incubation of BXPC3 and MCF7 cells with PPP resulted in acceleration of the initiation phase of thrombin generation. BXPC3 cells manifested higher procoagulant potential than MCF7 cells. The incubation of BXPC3 or MCF7 cells with the anti-TF monoclonal antibody which resulted in reversal of their effect on thrombin generation. The present study establishes a link between the amount of TF expressed by cancer cells with their procoagulant activity. Both studied types of cancer cells trigger thrombin generation but they have different procoagulant potential. The procoagulant activity of BXPC3 and MCF7 cells is related to the amount of TF expressed. Kinetic parameters of thrombogram are the most relevant for the detection of the TF-dependent procoagulant activity of cancer cells. TF expression is one of the mechanisms by which cancer cells manifest their procoagulant potential but it is not the unique one. The present experimental model will allow the characterization the procoagulant fingerprint of cell lines from the same or different histological types of cancer.