Marie-Louise Wiesel

Use of additive solutions and pathogen inactivation treatment of platelet components in a regional blood center: impact on patient outcomes and component utilization during a 3-year period.

BACKGROUND: The Etablissement Français du Sang Alsace (EFS Alsace) successively implemented universal use of platelet additive solutions (PASs) and pathogen inactivation (PI) for platelet components (PCs). To assess the impact of these changes, EFS Alsace evaluated PC use, red blood cell (RBC) component use, and transfusion‐related adverse events after implementation of these new technologies.

Prothrombin fragment 1 + 2 and thrombin-antithrombin III complex as markers of activation of blood coagulation in inflammatory bowel diseases

Objectives and methods: The aims of the present work were to assess the presence of thrombin generation in Crohns disease and in ulcerative colitis by using the prothrombin fragment 1+2 and the thrombin–antithrombin III complex assays and to study the possible relationships between these markers and disease activity. Results: Prothrombin fragment 1+2 and thrombin–antithrombin III complex were significantly raised in patients with Crohns disease (n=69) and with ulcerative colitis (n=25) as compared with healthy controls (n=50). In Crohns disease these two markers of thrombin generation were correlated with the Van Hees index (P<0.05 and P<0.001, respectively); values were significantly different from controls even in the patient group displaying the lowest disease activity (P<0.001). No correlation was found with tumour necrosis factor &agr; and C-reactive protein; nevertheless patients with C-reactive protein less than or equal to 10 mg/l had significant lower values of prothrombin fragment 1+2 (P<0.03). In ulcerative colitis prothrombin fragment 1+2 and thrombin–antithrombin III complex were significantly increased by comparison with controls, were higher in patients with pancolitis and correlated with C-reactive protein (P<0.002 and P<0.009, respectively). Conclusion: These data show that prothrombin fragment 1+2 and thrombin–antithrombin III complex are increased in inflammatory bowel diseases and suggest that thrombin generation might be an early event in their pathogenesis. European Journal of Gastroenterology & Hepatology 1995, 7:1183–1188

Prevalence and Significance of Anticardiolipin Antibodies in Crohn's Disease

Crohns disease is a chronic inflammatory bowel syndrome in which thrombotic complications occur in the active phase. Phospholipid-binding antibodies such as anticardiolipin antibodies and lupus anticoagulants have been shown to be associated with thrombosis. Their presence has been assessed in a group of 50 patients with Crohns disease among whom 44 had active disease. The overall prevalence of anticardiolipin antibodies was about 22%, while none of these patients had lupus anticoagulant. Anticardiolipin antibodies have been observed in both active and quiescent CD and their presence does not seem to be related to the site of CD lesions. The presence of phospholipid-binding antibodies could be a sign of vascular alterations that are potentially thrombogenicper se, and their predictive value with respect to the specific inflammatory syndrome of Crohns disease is discussed.

Impact of P2Y12 Inhibition by Clopidogrel on Cardiovascular Mortality in Unselected Patients Treated by Percutaneous Coronary Angioplasty: A Prospective Registry

OBJECTIVESnThe aim of this study was to determine whether low platelet response to the P2Y(12) receptor antagonist clopidogrel as assessed by Vasodilator-stimulated phosphoprotein flow cytometry test (VASP- FCT) predicts cardiovascular events in a high-risk population undergoing percutaneous coronary intervention (PCI).nnnBACKGROUNDnImpaired platelet responsiveness to clopidogrel is thought to be a determinant of cardiovascular events after PCI. The platelet VASP-FCT is a new assay specific to the P2Y(12) adenosine diphosphate receptor-pathway. In this test, platelet activation is expressed as platelet reactivity index (PRI).nnnMETHODSnFour-hundred sixty-one unselected patients undergoing urgent (n = 346) or planned (n = 115) PCI were prospectively enrolled. Patients were classified as low-response (LR) and response (R) to clopidogrel, depending on their PRI. Optimal PRI cutoff was determined by receiver-operator characteristic curve analysis to 61% (LR: PRI > or =61% and R: PRI <61%). Follow-up was obtained at a mean of 9 +/- 2 months in 453 patients (98.3%).nnnRESULTSnAt follow-up, total cardiac mortality rates and possible and total stent thrombosis were higher in LR patients. Multivariate analysis identified creatinine clearance (hazard ratio [HR]: 0.95; 95% confidence interval [CI]: 0.93 to 0.98, p < 0.001), drug-eluting stent (HR: 5.73; 95% CI: 1.40 to 23.43, p = 0.015), C-reactive protein (HR: 1.01; 95% CI: 1.001 to 1.019, p = 0.024), and LR to clopidogrel (HR: 4.00; 95% CI: 1.08 to 14.80, p = 0.037) as independent predictors of cardiac death. The deleterious impact of LR to clopidogrel on cardiovascular death was significantly higher in patients implanted with drug-eluting stent.nnnCONCLUSIONSnIn patients undergoing PCI, LR to clopidogrel assessed by VASP-FCT is an independent predictor of cardiovascular death at the PRI cutoff value of > or =61%. The LR clinical impact seems to be dependent on the type of stent implanted.

Long-Chain n-3 Fatty Acids Specifically Affect Rat Coagulation Factors Dependent on Vitamin K Relation to Peroxidative Stress

Abstract —Fatty acids of marine origin have been shown to affect blood coagulation in the rat. In an attempt to gain insight into the mechanisms of this phenomenon, we studied the effects of dietary linseed and fish oils on the liver antioxidant status and plasma coagulation parameters in rats on a time-course basis. Dietary enrichment in eicosapentaenoic and docosahexaenoic acids resulted in strong hypocoagulation after only 1 week and a concomitant increase in liver lipid peroxidation and tocopherolquinone content. Enrichment in linolenic acid induced similar increases in lipid peroxidation and tocopherol catabolism but negligible alteration of coagulation. A significant correlation between plasma factor II coagulant activity and liver tocopherolquinone was found in fish oil– but not in linseed oil–fed rats. Although ingestion of tocopherolquinone led to high levels of this compound in the liver, it had only marginal effects on coagulation factors. Thus, it seems unlikely that this vitamin E metabolite could be involved in the lowering of vitamin K–dependent clotting factors through inhibition of &ggr;-glutamylcarboxylase. Rather, our results indicate that the effects of the n-3 fatty acids of fish oil on vitamin K–dependent coagulation factors are specific and independent of liver tocopherolquinone levels.

Significance of Diminished Factor XIII in Crohn's Disease

Objective:Coagulation factor XIII is a plasma transglutaminase involved in crosslinking of fibrin, the last step of the coagulation system and a connective tissue factor contributing to the wound healing process. It circulates as a heterotetrameric molecule consisting of two identical proenzyme subunits (factor XIIIA) and two carrier protein subunits (factor XIIIS). The aim of this study was to determine the disease features associated with the diminution of factor XIII in Crohns disease.Methods:Factor XIIIA and factor XIIIS levels were assessed in patients presenting with Crohns disease, ulcerative colitis, infectious colitis, or diverticulitis, in patients with rheumatoid arthritis, and in control subjects. Prothrombin fragment 1 + 2 assay, as a marker of the generation of thrombin and measurement of C-terminal telopeptide of type I collagen as an estimate of degradation of collagen type I, were performed.Results:Factor XIIIA was significantly decreased in Crohns disease, in ulcerative colitis, and in infectious colitis by comparison with subjects presenting with diverticulitis, normal, and rheumatoid subjects p= 0.0001). Factor XIIIS was unmodified in patients with Crohns disease by comparison with controls but was reduced in those presenting with intestinal bleeding (p= 0.0002). In Crohns disease, the lowest level of factor XIIIA was observed in patients with intestinal bleeding (p= 0.0003). Factor XIIIA was correlated with the Van Hees index (r =−0.5661; p= 0.0001) and with the C-terminal telopeptide of type I collagen (r =−0.4110; p= 0.0011) but not with prothrombin fragment 1 + 2. The multiple regression analysis showed that only Van Hees index and intestinal bleeding were independent variables for explaining the diminution of Factor XIIIA in Crohns disease. Conclusions: Factor XIIIA subunit is an indicator of Crohns disease activity. Our study suggests that a low factor XIIIA level is related to the presence of intestinal lesions and might be linked to intestinal repair mechanisms; loss in intestinal lumen could be also involved, especially in patients with intestinal bleeding.

Screening of protein S deficiency using a functional assay in patients with venous and arterial thrombosis

Protein S is the vitamin K-dependent cofactor of activated protein C which functions as a potent anticoagulant by degrading activated factors V and VIII in a Ca2+ and phospholipid-dependent reaction. Protein S circulates under two forms, free (approximately 40%) or bound to C4b-binding protein (C4b-bp); only the free form supports the cofactor activity for activated protein C. Total protein S antigen is usually measured by rocket immunoelectrophoresis. Free protein S antigen is measured by the same technique but after precipitation of the protein S-C4b-bp complex by PEG 8000. However, these immunological assays do not detect functional alterations of protein S which can be responsible for thrombosis. This paper describes a functional assay for free protein S based on its ability to promote the prolongation of clotting time following factor Va inactivation by activated protein C when coagulation is triggered by factor Xa. Using this assay a prolongation of about 100 s between 0 and 1 U/ml protein S is measured, allowing a reliable and rapid determination of functional protein S. The correlation coefficient between functional protein S and free antigenic protein S is 0.921. This functional protein S assay has allowed the detection of 34 cases of protein S deficiency, confirmed by immunological assays, and their classification. The striking observation is the high frequency (approximately 25%) of arterial thrombosis in these patients. The rapid determination of functional protein S in patients with venous or arterial thrombosis is of diagnostic interest and should allow the detection of mutant protein S in combination with an immunological assay.

Antiphospholipid antibodies in inflammatory bowel disease

To The Editor: The presence of antiphospholipid antibodies (APA) is frequently associated with thromboembolic phenomena by as yet incompletely understood mechanisms (1). Inflammatory bowel disease (IBD) patients have a high incidence of thrombotic disease, and recent investigations suggest that microthrombi formation in bowel capillaries could be a determinant factor in IBD pathogenesis (2). Recently, Chamouard et al have reported in your journal a prevalence of anticardiolipin antibodies of about 22% in a sample of 50 patients with Crohns disease (3). They detected IgG isotype in five patients, IgM in three, and IgA in three. None of them had lupus anticoagulant. Other antiphospholipid antibodies were not investigated. We have measured serum levels of IgM and IgG anticardiolipin (ACL) and antiphosphatidilserine (APS) in 101 patients with IBD (75 ulcerative colitis, 26 Crohns disease; 30 in active phase, 71 in inactive). APA detection was performed essentially as described by Gharavi et al (4) using as antigens cardiolipin and phosphatidilserine from Sigma (St. Louis, Missouri). In our method, the cutoff levels of positivity (based on 97.5 percentile from 100 controls) were: <2.54 binding index (BI) for IgG ACL, <4.64 BI for IgM ACL, <2 BI for IgG APS, and <3.77 BI for IgM APS. We found only positive APA in five cases. One patient who had both anticardiolipinand antiphosphatidilserine-positive antibodies suffered from rheumatoid arthritis and had an ulcerative colitis in active phase. The remaining four cases had weak antiphosphatidilserine antibodies (<4.5 BI). All were inactive ulcerative colitis patients. None of them had history of thromboembolic events. No patient with Crohns disease had positive APA. In immunological disorders, such as rheumatoid arthritis, there is a known high prevalence of APA, so if we exclude the patient with rheumatoid arthritis, prevalence of positive APA in our sample of IBD patients was 3.9% (95% confidence interval 0.1-9.8), almost equal to that observed in the healthy population (5). Hudson et al also found an absence of lupus anticoagulant--an antibody closely related with APA--in this disease (6), and in the study by Webberly et al, anticardiolipin antibodies were absent in 103 of 104 patients (7). However, these results disagree with those of Reicht et al (8), who found a significantly higher prevalence of anticardiolipin antibodies in their sample of 121 patients compared to healthy controls; indeed they found that prevalence in Crohns disease was at least 25%. In our opinion, these contradictory results could be explained by either methodological differences or by distinct positivity thresholds for each antibody. Thus, new data are necessary to resolve these discrepancies because our study (and others) almost discards the implication of APA in thromboembolic alterations in IBD patients, due both to the low observed prevalence and to their low titers in the few positive cases, but results from Chamouard et al and Reicht et al may indicate a higher risk for APAassociated disorders in IBD and may imply a pathogenic role of APA in the genesis of IBD, especially in Crohns disease.

Two independent domains of Factor VIII co-expressed using recombinant vaccinia viruses have procoagulant activity

Using recombinant DNA technology, the NH2 and COOH terminal domains of the human Factor VIII molecule were co-expressed in baby hamster kidney 21 (BHK21) cells using the vaccinia virus system. Procoagulant activity was detectable in cell supernatants, thus suggesting that the central portion present in the FVIII protein (domain B) is not required for FVIII function.

Diets enriched in (n-3) fatty acids affect rat coagulation factors dependent on vitamin K

The effects of dietary lipids on haemostasis were investigated in rats fed high fat diets enriched in saturated fatty acids (SAT), oleic acid (OLEIC), MaxEPA oil (MaxEPA), eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) and results were compared to those for rats fed standard chow (ST). Coagulant activities of factor IIc and factor VII-Xc were reduced by about 70% in the MaxEPA group and 50% in the EPA and DHA groups relative to the OLEIC, SAT and ST groups. Liver vitamin K levels were five times lower in the experimental groups than in the ST group, which would indicate an effect of high fat diets on vitamin K metabolism. However, only (n-3) fatty acids prolonged the prothrombin time. These components could act at the post-translational modification level of vitamin K-dependent plasma clotting factors. The changes in haemostatic factors found in the MaxEPA group were counteracted by vitamin K supplementation.