Duchemin, G.; Kiss, G.; Gueret, G.; Rossignol, B.; Corre, O.; Kerautret, P.; Blouch, M. T.; Abgrall, J. F.; Goerlinger, K.1; Arvieu, C. C. Author Information

Montelukast (Singulair ®) has been reported to be a potent and selective antagonist of cysteinyl leukotriene (LT) D4 receptor (1). Its extended action after oral intake has made it the most useful antileukotriene for continuous treatment of asthma, in association with classical medications (2). Until now, Montelukast, at least at licensed doses, has not been reported to be associated with important adverse effects and abnormal laboratory values (3, 4). However, rare cases of bruising and increased tendency to bleeding have been observed, but the imputability of montelukast was not ascertained. We report here a 41-year-old woman who was referred for recurrent epistaxis and gingival and post-traumatic bleeding before surgical intervention. Before asthma was diagnosed, about 9 years ago, she carried 4 pregnancies to term, 2 miscarriages and many surgical interventions in childhood without bleeding complications. She had no family history of bleeding. Asthma was managed with bronchodilator medications, intermittent pulsed doses of corticosteroids and, since 1998, montelukast sodium. Four years before this observation, she had menorraghia; moreover, a dental extraction was complicated with excessive bleeding. Hematologic data was as follows: hemoglobin 13.3 g/dl, leukocytes 8.6 109/l, and platelets 292 109/l. Prothrombin time, activated partial thromboplastin time, fibrinogen and C-reactive protein were within normal range. Study of von Willebrand factor showed normal results (factor VIII activity: 66%; ristocetin cofactor activity: 52%; von Willebrand factor Ag: 62%) for a O blood group patient. A prolonged closure time (CT) measured with PFA-100® (CT-epinephrine: 222 sec.; CT-ADP: 145 sec. – Normal: < 165 sec. and < 118 sec. respectively) prompted us to study platelet aggregation. The aggregation was impaired with all the agonists except ristocetin (figure). In the presence of montelukast, the maximum response to ADP, epinephrine, collagen and arachidonic acid was inhibited by 16%, 65%, 33%, and 47% respectively. At a concentration of 10-6 M, ADP-induced aggregation was markedly reduced and no second wave was observed. Collagen-induced aggregation showed a longer lag phase and, noteworthy, a lag phase was also observed in arachidonate-induced aggregation. Acquired thrombopathia related to montelukast therapy

Analysis of speckle dynamics is frequently used to study the motion of scattered objects or liquids. By assessing the increase in contrast on the speckle field produced by a blood plasma sample, illuminated by a laser during a coagulation test, as well as the slowing down of speckle fluctuations, we measured the time required for blood plasma coagulation in vitro and evidence the process dynamics. Then, we compared this noninvasive method with a mechanical viscosity-based detection system classically used in hematology laboratories; our results show good correlation and could provide more information about the blood clotting process.

We report on a new method based on speckle size analysis and devoted to particle aggregation measurements. The experimental measurements give the speckle size variation during a salt aggregation process of polystyrene microspheres. The measurements are taken at a fixed monomer concentration, varying the salt concentration. Moreover, we applied this technique to follow blood platelet aggregation, usually monitored with a visible light transmittance photometer (aggregometer). Aggregation process was induced by ADP (adenosine diphosphate) addition, then we measured the speckle size variation versus time at two different ADP concentrations.

BACKGROUND AND OBJECTIVES:A high level of coagulant factor VIII is a well known risk factor for venous thromboembolism, but most studies have enrolled patients under 70 years old. This study aimed to test the hypothesis that an association also exists in the elderly. DESIGN AND METHODS:This hospital-based case-referent study took place at the Department of Internal Medicine and Chest Diseases, University Hospital, Brest, France. We enrolled 161 patients with a first episode of venous thrombosis and 239 subjects, referred for a clinical suspicion of venous thromboembolism which was subsequently ruled out. Factor VIII coagulant activity and plasma fibrinogen concentration were measured. RESULTS:High factor VIII coagulant activity was significantly associated with venous thromboembolism, irrespective of the age group. Patients over 70 years with factor VIII coagulant activity above 225% had a 2.4-fold increased risk of venous thromboembolism compared to those patients with levels below 130% (age- and fibrinogen-adjusted odds ratio: 2.6, 95% CI 1.1 to 6.1). INTERPRETATION AND CONCLUSIONS:Our results show that high levels of factor VIII coagulant, a determinant of venous thrombosis in adulthood, is also a risk factor in the elderly.

C-reactive protein (CRP) is one of the main independent predictors of cardiovascular events. Oral post-menopausal estrogen replacement therapy (ERT) increases CRP levels, but the effect of transdermal ERT is not well documented. CRP, interleukine-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) levels were evaluated in a randomised study of 196 healthy postmenopausal women, who were allocated to receive continuous oral estradiol-1beta, (n=63) or transdermal estradiol-1beta, (n=68) both combined with micronised progesterone, or place-bo (n=65). Oral estrogen increased CRP levels compared with both placebo (p=0.010) and transdermal estrogen (p=0.004) at 6 months. There was no significant effect of transdermal estrogen on CRP levels compared with placebo (p=0.997). No significant difference was found in the median changes for IL-6 and TNF-alpha between the three treatment groups. In conclusion, transdermal estrogen has no significant effect on CRP levels at 6 months, but CRP concentrations increased significantly with oral estrogen although no changes in cytokine levels were detected. The clinical relevance of these effects remains to be determined.

Objective—Activated protein C (APC) resistance not related to the factor V Leiden mutation is a risk factor for venous thrombosis. Oral estrogen replacement therapy (ERT) has been reported to induce APC resistance. Little is known about the effect of transdermal estrogen. Methods and Results—We enrolled 196 postmenopausal women who were randomly allocated to receive either 1 mg 17&bgr;-estradiol orally (n=63) or 50 &mgr;g 17&bgr;-estradiol transdermally per day (n=68), both associated with 100 mg progesterone daily or placebo (n=65) for 6 months. An activated partial thromboplastin time (APTT)–based test and the effect of APC on thrombin potential (ETP) were used. Oral ERT induced an ETP-based APC resistance compared with both placebo (P =0.006) and transdermal ERT (P <0.001), but there was no significant effect of transdermal ERT compared with placebo (P =0.191). There was no significant effect of ERT on the APTT-based APC sensitivity ratio. Prothrombin fragment 1+2 plasma levels were significantly higher after 6 months of treatment in women allocated to oral ERT compared with those on placebo and transdermal ERT and were positively and significantly correlated with changes in ETP-based APC sensitivity ratio. Conclusions—Our data show that oral, unlike transdermal, estrogen induces APC resistance and activates blood coagulation. These results emphasize the importance of the route of estrogen administration.

Madame R., 75 ans, suivie pour une LMMC (leucemie myelo-monocytaire chronique) en abstention therapeutique, est hospitalisee en hematologie pour alteration de l'etat general. Le bilan d'hemostase d'entree revele un allongement important du temps de cephaline active (TCA) a 98 secondes (temoin a 33 secondes), le taux de prothrombine est normal, de meme que le temps de thrombine (tableau 1). Un bilan de coagulation realise trois mois plus tot indiquait un taux de prothrombine (77 %) et un TCA (41 secondes) normaux. Un anticoagulant circulant est detecte, mais les tests de confirmation d'un lupus anticoagulant sont negatifs : temps de thromboplastine diluee (TTD)

Inhibitors against factor XI (FXI) have been frequently described in patients who acquired inhibitors (due to auto-immune disorders, malignancies or infections), but less often in those with a congenital deficiency of this factor, who had received plasma infusions. The present report concerns one such inhibitor found in the plasma of a patient with chronic myelomonocytic leukaemia and infected by B19 parvovirus, who was neither a heterozygote nor a homozygote for FXI deficiency, and who had no bleeding tendency despite a very low FXI level. Taking this case into account, we discuss and present the clinical and biological features of acquired FXI deficiency caused by an inhibitor.

OBJECTIVE:To determine the prevalence of anti-endothelial cell antibodies (AECA) in various forms of vasculitis and to evaluate their relationships with markers of endothelial cell (EC) injury such as thrombomodulin (TM), von Willebrand factor antigen (vWf) and protein S.METHODS:A total of 167 disease-associated sera, from 79 patients with large- or medium-sized (group I) and 88 with small-sized vessel vasculitis (group II), were examined for the presence of AECA using a cellular enzyme-linked immunosorbent assay (ELISA). These were evaluated before and after incubation with epithelial cells. EC plus epithelial cell (eC) extracts were fractionated and blotted with selected sera, and EC plus mononuclear cell extracts were dotted and blotted with lupus sera. Soluble TM, vWf and protein S levels were measured by ELISA.RESULTS:The binding of antibodies to eC was significant in group II sera (p < 0.01) but not in group I sera, so that the remaining EC-specific activity was significantly higher (p < 0.001) in the latter group than in the former. Eight antigenic specificities appeared to be specific for EC, whereas three were shared with eC. Despite absorption, the sera remained as reactive with EC and MNC as before. Taking the patient group as a whole, the levels of serum TM correlated with the titers of IgG, IgM and IgA AECA.CONCLUSION:EC-specific activity is more often encountered in group I than in group II patients. At present, the explanation for the distinct AECA specificities in these disease associated sera is not clear.

A survey was carried out of the attitudes adopted in French laboratories with regard to the diagnosis of heparin-induced thrombocytopenia (HIT). The platelet aggregation assay is used in 100% of laboratories, aggregation being measured by light transmission in an aggregometer (3/4). Blood is drawn either in emergency (1/4) or after heparin discontinuation (1/4). The nature of the samples for testing is a fresh citrated plasma (100%) although frozen plasma is occasionally employed, while 40% of laboratories use less than 3 control platelet donors. Platelet response is verified in the presence of a non immune agonist (18%) or an immune challenge (known positive plasma or platelet activating monoclonal antibody) (13%). Heparin is of the same type as received by the patient and is tested at two or more concentrations of approximately 0.5 and 1.0 IU/ml, but rarely at high concentration (100 IU/ml). The platelet count is adjusted to 250 - 350 x 10(9)/l (18%), the ratio of patient plasma to PRP is 1:1 (59%), the time of observation is about 20 min (50%) and control platelets are tested with heparin to rule out any false positive results (9/10). Standardization is nevertheless required if the platelet aggregation assay is to be considered as a reference test.

Seventeen patients with primary thrombocythemia (PT) were evaluated for in vitro bone marrow megakaryocyte progenitors (CFU-MK) using a plasma clot system. The aim of this study was to find out whether spontaneous growth of CFU-MK could be used in the diagnosis of PT. The number of CFU-MK was normal in 7 patients and reduced in 10 patients. In the absence of stimulating factor, CFU-MK grew spontaneously in 12 patients, while in 5 patients no spontaneous CFU-MK were observed. The mean plasma level of platelet factor 4 (PF4) was significantly higher (p < 0.05) in patients without spontaneous CFU-MK (59.8 +/- 59.6 IU/ml; mean +/- SD) compared to patients with (18.1 +/- 20.7 IU/ml). The mean plasma level of beta-thromboglobulin did not differ between patients with or without spontaneous CFU-MK. The beta-thromboglobulin/PF4 ratio was significantly higher (p < 0.01) in patients with spontaneous CFU-MK (9.9 +/- 7.1) compared to patients without (3.1 +/- 1.4). These results suggest that PF4 could inhibit in vitro spontaneous growth of CFU-MK.