Correction to: New clotting disorders that cast new light on blood coagulation and may play a role in clinical practice.

The original version of the article unfortunately contained few errors.

Heparin, coumarin, protein C, antithrombin, fibrinolysis and other clotting related resistances: old and new concepts in blood coagulation.

The concept of resistance in blood coagulation has become important. In the past it was limited to the resistance shown by some patients to heparin, coumarin or aspirin. Subsequently, it was demonstrated that a mutation in a single clotting factor, FV, showed resistance to activated protein C. Since activated protein C is supposed to downregulate aFV and aFVIII, their persistence in the circulation gives origin to a hypercoagulable state. Recently antithrombin resistance has been defined. Several prothrombin abnormalities (dysprothrombinemias) have been shown to be resistant to the action of antithrombin. This is associated with the occurrence of a trombophilic state. Prothrombin may therefore be associated like FV with both a bleeding condition (prothrombin deficiency) and a thrombophilic state (some dysprothrombinemias). Finally, thrombomodulin resistance has been defined in liver cirrhosis. These patients often show an increased ratio between FVIII levels and protein C. This imbalance may be partly responsible for the frequent presence of portal vein thrombosis seen in these patients. All these studies have greatly increased the complexity of the clotting mechanisms and interactions. They have cast light on clinical events which had remained unknown or ill-defined.

New clotting disorders that cast new light on blood coagulation and may play a role in clinical practice.

Recently several variants of clotting factors have shown a peculiar behavior so that they appear as new defects. The factors involved are FII, FV and FIX. Prothrombin deficiency is usually associated with bleeding. Recently a few prothrombin abnormalities involving Arg396 mutations, have been demonstrated to show antithrombin resistance with the consequent appearance of a thrombophilic state and venous thromboses in young age. The same is true for an abnormal FIX (FIX Padua). The thrombotic manifestations in the latter condition are also venous. The abnormal FIX (FIX Padua) is characterized by a great increase in FIX activity whereas FIX antigen is only slightly increased. The condition is due to an Arg338Lys mutation. The increased intrinsic clotting activity of this abnormal FIX is being investigated as a useful therapeutic approach in homophile B patients. Another new clotting disorder is represented by two abnormal FV (FV East Texas and FV Amsterdam). These are characterized by a deletion of part of the B domain of FV resulting in a "short" FV. The condition is characterized by a mild bleeding tendency due to high levels of Tissue Factor pathway inhibitor. The "short" factor V is in fact resistant to the action of Tissue Factor pathway inhibitor which is sharply increased in these patients. These new clotting entities have again demonstrated that the study of patients who show a tendency to venous thrombosis or a mild bleeding condition that cannot be explained on the basis of our current concepts of blood coagulation, may represent "new" coagulation disorders. All persons interested in thrombotic or hemorrhagic disorders should be informed about these new clinical and laboratory conditions.

Prethrombotic, prothrombotic, thrombophilic states, hypercoagulable state, thrombophilia etc.: semantics should be respected even in medical papers.

The study of prothrombotic or thrombophilic states have drawn considerable attention during the past two decades. This was the result of the increasing number of thrombotic events, both arterial and venous reported all over the world but especially in the developed countries. This wealth of studies and papers have not always respected the semantical significance of the various terms used, namely prethrombotic state, hypercoagulable state, thrombophilic or prothrombotic state, thrombophilia, susceptibility to thrombosis and procoagulant state. This review is an attempt to adhere to a correct Semantic format in order to avoid confusion and misinterpretations. This is of fundamental importance in order to avoid the wrong attribution of a thrombosis to a hypercoagulable or a prethrombotic state.

Thrombotic Events in Asymptomatic FXII Deficiency versus Symptomatic FXI Deficiency: Surprising Observations.

OBJECTIVE: To evaluate the impact of an asymptomatic congenital clotting defect (FXII deficiency) versus that of a similar but symptomatic defect (FXI deficiency) on protection from thrombosis. PATIENTS AND METHODS: All patients with FXII or FXI deficiency and thrombosis were gathered from a time-unlimited PubMed search that was carried out twice and from personal records. Combined defects were excluded. The defect had to be proven by the demonstration of a suited hereditary pattern and by a specific clotting assay. Only patients with a factor activity level of <30% of normal were selected. RESULTS: Twenty-eight patients with an FXII deficiency presented with arterial thrombosis, mainly myocardial infarction, and 29 showed venous thrombosis; for FXI deficiency, these figures were 43 and 10, respectively. The ratio of arterial and venous thrombosis was 0.96 and 4.3, respectively, for FXII and FXI deficiency. CONCLUSIONS: Factor FXII deficiency supplies no protection from arterial or venous thrombosis. FXI deficiency shows no protection from arterial thrombosis but appears to guarantee protection from venous thrombosis. A symptomatic, namely bleeding, condition (FXI deficiency) provides protection from venous thrombosis whereas an asymptomatic one (FXII deficiency) does not.

Pathogenetic role of Factor VII deficiency and thrombosis in cross-reactive material positive patients.

Congenital Factor VII (FVII) deficiency can be divided into two groups: cases of "true" deficiency, or cross-reactive material (CRM) negative and variants that are cross-reactive material positive.The first form is commonly recognized as Type I condition whereas the second one is known as Type II. FVII deficiency has been occasionally associated with thrombotic events, mainly venous. The reasons underlying this peculiar manifestation are unknown even though in the majority of associated patients thrombotic risk factors are present. The purpose of the present study was to investigate if a thrombotic event was more frequent in Type I or in Type II defect.The majority of patients with FVII deficiency and thrombosis belong to Type II defects. In the following paper we discuss the possible role of the dysfunctional FVII cross-reaction material as a contributory cause for the occurrence of thrombosis.

Consumer preference for chicken breast may be more affected by information on organic production than by product sensory properties.

Conventional chicken from a fast-growing strain (CC), organic chicken from a slow-growing strain (OSG), and organic chicken from a fast-growing strain (OFG) were used to assess descriptive sensory differences between organic and conventional breasts, to verify whether differences were perceived by consumers and to evaluate the effect of information about organic production on liking. A conventional quantitative-descriptive analysis was performed by a trained panel of 10 members on breast slices (1 cm thick) grilled at 300°C. A 150-member consumer panel (from southern, central, and northern Italy) rated CC, OSG, and OFG breasts according to 3 types of evaluation: tasting without information (perceived liking), information without tasting (expected liking), and tasting with information (actual liking). Breasts from different sources were clearly discriminated by the trained panel as meat from CC was perceived more tender than OFG (P < 0.05) and OSG (P < 0.001), more fibrous than OFG (P < 0.05) and OSG (P < 0.001), and leaving more residue than OFG (P < 0.05) and OSG (P < 0.001), whereas OSG was assessed as less juicy before swallowing than OFG and CC (P < 0.05) and less fibrous than OFG (P < 0.05). No significant differences were observed by consumers for perceived liking. However, consumer expected liking scores were higher for organic than for conventional products (P < 0.001) and actual liking of organic breasts moved toward the expectancy. In particular, actual liking scores were higher than perceived liking in blind conditions (P < 0.001 and P < 0.01 for OFG and OSG, respectively). We conclude that trained panelists were able to discriminate chicken breasts from different sources, whereas untrained consumers were not. However, consumer liking was markedly affected by the information given on the organic production system, thus providing a tool to differentiate the product in an increasingly competitive market.

Persistent validity of a classification of congenital factor X defects based on clotting, chromogenic and immunological assays even in the molecular biology era.

An adequate classification of congenital bleeding disorders is of great importance in clinical practice. This is true also for factor X (FX) deficiency. This defect is classified in two forms: type I (cases with low activity and antigen) and type II (cases with low activity and variable levels of antigen). The introduction of molecular biology techniques has allowed a classification based on the site of mutation (propeptide, Gla-domain, catalytic domain etc.) or on the type of mutation (missense, nonsense, deletion etc.). However, with a partial exception for defects in the Gla-domain, no site or type of mutation yields a constant and/or typical phenotype. Due to these difficulties, a classification based on clotting, chromogenic or immunological assays is still the most suited for clinical purposes. A satisfactory classification that takes into account recent advances of FX deficiency could read today as follows: • Type I (cross-reacting material (CRM) negative) (Stuart like) • Type II (CRM positive with inert protein) (Prower like) • Type III (CRM positive with disreactive protein) 1. Defects in all activity systems but for RVV activation (Friuli like) 2. Defects only or predominantly in the extrinsic-Xase system (Padua like) 3. Defects only or predominant in the intrinsic-Xase system (Melbourne like) 4. Defects with discrepant (high) chromogenic assays. Finally, type IV should be added to include cases of FX deficiency associated with FVII deficiency usually due to chromosome 13 abnormalities. By using this nosographic approach, all reported cases of FX deficiency can be adequately allocated to one of these groups.

Comparative incidence of thrombosis in reported cases of deficiencies of factors of the contact phase of blood coagulation.

Thrombotic manifestations occurring in patients with coagulation defects have drawn considerable attention during the last decade. It concerned mainly patients with hemophilia, vW disease or FVII deficiency. Occasional reports involved also the deficiencies of the contact phase of blood coagulation, mainly FXII deficiency. The purpose of the present study was to evaluate the comparative incidence of thrombosis in all reported patients with FXII, Prekallikrein and Kininogens deficiencies. Out of the reported 341 cases with these conditions that could be tracked there were 43 cases with thrombosis. More specifically, there were 32 patients with FXII deficiency who also had a thrombotic event (16 arterial and 16 venous). As far as Prekallikrein deficiency is concerned, there were nine cases with thrombosis (five arterial and four venous). Finally, two patients with Total or High molecular weight Kininogen deficiencies had also a thrombotic manifestation (one arterial and one venous). The thrombotic manifestations were M.I. 11 cases; ischemic stroke 9 cases; peripheral arteries 3 cases; deep vein thrombosis with or without pulmonary embolism 17 cases; thrombosis in other veins 3 cases. Congenital or acquired associated prothrombotic risk factors were present in 33 out of 36 cases. In three cases the existence of associated risk factors was excluded whereas in the remaining seven patients no mention is made in this regard. This study clearly indicates that the severe in vitro coagulation defect seen in these conditions does not protect from thrombosis.

Similarities and discrepancies in homozygous factor VII defects due to mutations in the region of residues Met298 to Cys310 (exon 8) in the catalytic domain of factor VII.

Patients with the Arg304Gln mutation in factor VII Padua (FVII Padua) show discrepant activity levels that depend on the thromboplastin used in the assay system. This report investigates the possibility that residues close to Arg304 (exon 8) show the same discrepant behavior. All available homozygous patients with a mutation in a 13-residue region (preceding and following Arg304) have been evaluated. Only the Arg304Trp mutation showed a discrepancy similar to that shown by the Arg304Gln mutation. Other homozygotes failed to show differences, despite their all being positive for cross-reacting material. Another FVII amino acid residue involved in tissue factor binding and activation is Arg79 (exon 4). No comparison could be carried out because no homozygotes for deficiency in this region have ever been described. The relationship between these 2 residues involved in tissue factor binding and activation has not yet been completely clarified; however, Arg residues 79 and 304 are the only 2 residues definitely shown thus far to be involved in this important function.

Thrombotic events in patients with congenital prekallikrein deficiency: a critical evaluation of all reported cases.

The occurrence of thrombotic events in patients with congenital bleeding conditions has received considerable attention in recent years. The same is true for asymptomatic defects of factors of the contact phase of blood coagulation, mainly FXII. Anecdotal reports on thrombosis in patients with prekallikrein deficiency have occasionally been reported. These involved both arterial and venous thrombosis. The purpose of the present article is to analyze the stories and the clinical pictures of all 75 cases of prekallikrein deficiency published so far. Among these patients were 9 with thrombosis, 6 arterial (myocardial infarction and ischemic stroke) and 3 venous (deep vein thrombosis with or without pulmonary embolism). In 6 cases acquired thrombosis risk factors were present; in 2 cases no associated risk factors were present and in 1 case no information was supplied in this regard. One patient who presented both a stroke and a pulmonary embolism had a fatal outcome. The article clearly indicates that prekallikrein deficiency does not protect from thrombosis in spite of the severe in vitro coagulation defect.

Ox brain versus rabbit brain thromboplastin assays are the best tool for a preliminary diagnosis of the Arg304Gln factor VII defect (FVII Padua).

Factor VII (FVII) deficiency, the most frequent defect among the rare bleeding disorders, is commonly divided into type I and type II. In the former, there is a concomitant decrease in FVII activity and antigen. In the latter, there is a clear discrepancy between activity which is low and antigen which is normal or nearly normal. FVII Padua (Arg304Gln) is characterized by different reactivity towards different tissue thromboplastins. FVII levels were assayed by the use of different tissue thromboplastins, namely rabbit brain, human placenta, human recombinant and ox brain thromboplastin, in 6 homozygous patients. Cases reported in the literature were also evaluated. Ox brain thromboplastins yielded normal values, whereas human tissue or recombinant human thromboplastins yielded only slightly higher levels of activity than those obtained with rabbit brain reagents. The ox brain versus rabbit brain ratio was about 22, whereas the ratio for human placenta or human recombinant versus rabbit brain thromboplastin was only about 5. The FVII antigen versus rabbit brain, human tissue and ox brain activity ratios were 24.8, 4.3 and 1.1, respectively. These results indicate that the ox brain versus the rabbit brain thromboplastin ratio supplies a wider difference than the one between human tissue and rabbit brain. The antigen/ox brain activity ratio of 1.1 fully confirms this assertion.

Associated prothrombotic conditions are probably responsible for the occurrence of thrombosis in almost all patients with congenital FVII deficiency. Critical review of the literature.

The occasional occurrence of thrombosis in patients with congenital bleeding disorders has received considerable attention during the past decade. Myocardial infarction, ischemic strokes and venous thromboembolism have been reported in hemophilia A or B patients, in von Willebrand disease and, also, in rare coagulation disorders, especially in factor VII (FVII) deficiency. To explain the relatively high frequency of thrombotic phenomena, mainly venous, seen in the last condition, it was speculated that a special form or variant of FVII deficiency could exist. The presence of associated prothrombotic risk factors has been occasionally reported to be present in these patients but the matter has never been duly evaluated and emphasized. The purpose of the present paper was to evaluate if the clinical setting in which thrombosis appeared in these patients could explain the occurrence of the thrombosis. All reported cases of thrombosis seen in patients with FVII deficiency have been analyzed and the presence of associated risk factors recorded. Out of a population of 33 documented cases, the presence of prothrombotic risk factors was reported in 30 instances. In two of the remaining cases, no mention is made about associated risk factors. In the last case they were explicitly excluded. The critical evaluation of the literature suggests that the occurrence of thrombosis in FVII deficiency may be due to common prothrombotic risk factors. As a consequence it may be only stated that FVII deficiency does not protect from thrombosis.

Hemospermia in patients with congenital coagulation disorders: a study of three cases.

Hemospermia is usually a symptom of urological relevance, however it may have also a medical and hematological significance and has been reported in congenital or acquired bleeding disorders. Because of this symptom's negative psychological impact on the patient, it is likely that the condition is underplayed and therefore underdiagnosed. During the years 1967-2003 we had the opportunity to see 3 patients with hemospermia on a congenital bleeding disorder: a patient with hemophilia A, another with prothrombin deficiency and finally a patient with von Willebrand disease type I. All patients were heterosexual. In all instances the course was benign since it required administration of substitution therapy on only 2 occasions. Rest and abstinence from sexual activity appeared to be helpful. The first patient had other signs and symptoms compatible with the diagnosis of urethritis due to Escherichia coli and he underwent a course of antibiotic therapy. The other 2 cases appeared to be idiopathic since no associated condition was found. Urinary cytology, rectal examination, prostate sonography and prostate-specific antigen were normal in all cases. The rarity of hemospermia in congenital bleeding disorders remains unexplained, although the strong perineal and sphincter muscles may exercise a compressive hemostatic effect which could prevent or reduce bleeding.

Congenital FX deficiency combined with other clotting defects or with other abnormalities: a critical evaluation of the literature.

The presence of more than one congenital clotting defect in a given patient is a rare event but not an exceptional one. Combined defects of factor X (FX) are very rare because congenital isolated FX deficiency is by itself very rare. A perusal of personal files and of the literature has yielded 12 families with FX deficiency in which an association with another clotting factor deficiency was found. The associated defects were factor VII (FVII) or factor VIII (FVIII) or factor XII (FXII) deficiency. By far the most frequently associated was with FVII. Two forms of this association were found. In the first form there is casual association of both FVII and FX deficiency in the proband with independent recessive segregation of the two defects in other family members. The second form is because of abnormalities in chromosome 13 (deletions, translocations and so on) involving both FX and FVII genes. These genes are known to be very close and located on the long arm of chromosome 13 at about 13q34. In this form the hereditary pattern is autosomal dominant. Isolated FX deficiency and, more frequently, combined FX + FVII deficiency appear also associated with coagulation-unrelated abnormalities (carotid body tumours, mitral valve prolapse, atrial septal defect, ventricular septal defect, thrombocytopenia absent radius (TAR) syndrome, mental retardation, microcephaly and cleft palate). Diagnosis of a combined clotting defect could be difficult on the basis of global tests. For example, both isolated FX deficiency and combined FX + FVII deficiency yield a prolongation of basal PTT and PT. Only specific assays could allow one to reach the correct diagnosis. In cases of casual association with other defects, it is also important to study family members, as the two defects should segregate independently.

Control of ovulation-induced hemoperitoneum by oral contraceptives in a patient with congenital hypoprothrombinemia and in another with congenital factor V deficiency.

Hemoperitoneum is a serious and often life-threatening bleeding manifestation. This is particularly true for women who carry congenital bleeding disorders. We describe here a hemoperitoneum occurring in 1 patient with congenital prothrombin deficiency and another with congenital factor V deficiency. Both patients have been followed by us for many years. The patient with prothrombin deficiency underwent laparoscopy but was treated consecutively with whole blood, plasma transfusions and 1,000 units of prothrombin complex concentrates. Response was good and she was then placed on oral contraceptives (OC) which prevented any recurrence. The patient with factor V deficiency presented several episodes of ovulation-related bleeding which required hospitalization and fresh frozen plasma transfusions. On the fifth occasion, the patient had to undergo surgery, and a left oophorectomy was carried out. After this last episode, she was also placed on OC which were very effective in preventing further recurrences. Both patients tolerated the medications very well which, in addition, were able to control menometrorrhagia with a consequent decrease over time in transfusional needs. OC are the treatment of choice in congenital bleeding disorders to control both the menorrhagia and, more importantly, ovulation-related hemoperitoneum.

Effect of information about animal welfare on consumer willingness to pay for yogurt.

This study aimed to verify whether consumers confirm their willingness to pay extra costs for higher animal welfare standards in a situation where a potential purchase performed by consumers, such as the Vickrey auction, is used. A 104-member consumer panel was asked to rate its willingness to pay (WTP) for plain and low-fat yogurts in 3 information conditions: tasting without information (blind WTP), information about animal welfare without tasting (expected WTP), tasting with information about animal welfare (actual WTP). Information was provided to the consumers under the form of labels indicating the level of animal cleanliness and freedom of movement (5-point scale, from poor to very good). Consumers were influenced by information about low standards of animal welfare (low cleanliness and low freedom of movement) and moved their willingness to pay in the direction of their expectations. However, the discrepancy between expectancy and actual WTP was not totally assimilated, indicating that WTP was also expressed in relation to other aspects (e.g., the sensory properties of the products). Conversely, the information concerning high standards of animal welfare (high cleanliness and high freedom of movement) was able to affect expectancy but had an effect on actual WTP only when the most acceptable yogurt was offered to the consumers. In the case of discordant information on animal welfare, partly indicating high levels of welfare (freedom of movements) and low levels of welfare (cleanliness), expected WTP was always lower than blind WTP. However, when the least acceptable product was presented, they completely assimilated their actual WTP to the expectations. Conversely, with the most acceptable yogurt, no assimilation occurred and sensory properties prevailed in orienting consumer WTP. Within each product, consumers expressed a higher WTP for products with labels indicating high welfare standards as compared with yogurts with labels reporting intermediate and low welfare standard. These results show that information about animal welfare, if given to the consumers, can be a major determinant of consumer WTP for animal-based food products. However, information about high standards of animal welfare should be paired with products presenting a good eating quality.

Interaction of asialo von Willebrand factor with glycoprotein Ib induces fibrinogen binding to the glycoprotein IIb/IIIa complex and mediates platelet aggregation.

von Willebrand factor (vWF) is necessary for the initial attachment of platelets to exposed subendothelium, particularly under flow conditions like those prevailing in the microcirculation. Little is known about its possible participation in subsequent events leading to formation of platelet thrombi at sites of vascular injury. We addressed this question by studying the mechanisms by which desialylated vWF induces platelet aggregation in the absence of any other stimulus. Asialo vWF, unlike the native molecule, does not require ristocetin to interact with platelets. Agglutination induced by ristocetin is largely independent of active platelet metabolism and only partially reflects physiological events. We have shown here that binding of asialo vWF to platelets was accompanied by release of dense granule content and subsequent ADP-dependent fibrinogen binding to receptors on the glycoprotein (GP) IIb/IIIa complex. The initial interaction of asialo vWF with platelets was mediated by GPIb, as shown by blocking obtained with monoclonal antibody. Inhibition of this initial interaction completely abolished platelet aggregation induced by asialo vWF. The same effect was obtained with a monoclonal anti-GPIIb/IIIa antibody. This, however, did not block asialo vWF binding to platelets, but rather inhibited subsequent fibrinogen binding induced by asialo vWF. Therefore, the latter process was also essential for platelet aggregation under the conditions described. At saturation, asialo vWF induced binding of between 3.2 and 27.7 X 10(3) fibrinogen molecules/platelet, with an apparent dissociation constant between 0.28 and 1.18 X 10(-6) M. This study shows that asialo, and possibly native, vWF acts as a platelet agonist after its binding to GPIb and induces aggregation through a pathway dependent on GPIIb/IIIa-related receptors.

von Willebrand factor interaction with the glycoprotein IIb/IIa complex. Its role in platelet function as demonstrated in patients with congenital afibrinogenemia.

We have studied three afibrinogenemic patients, who had only trace amounts of plasma and platelet fibrinogen as measured by radioimmunoassay, and demonstrate here that the residual aggregation observed in their platelet-rich plasma is dependent upon von Willebrand factor (vWF) binding to the platelet membrane glycoprotein (GP)IIb/IIIa complex. The abnormality of aggregation was more pronounced when ADP, rather than thrombin, collagen, or the combination of ADP plus adrenaline was used to stimulate platelets. With all stimuli, nevertheless, the platelet response was completely inhibited by a monoclonal antibody (LJP5) that is known to block vWF, but not fibrinogen binding to GPIIb/IIIa. Addition of purified vWF to the afibrinogenemic plasma resulted in marked increase in the rate and extent of aggregation, particularly when platelets were stimulated with ADP. This response was also completely blocked by LJP5. Addition of fibrinogen, however, restored normal aggregation even in the presence of LJP5, a finding consistent with the knowledge that antibody LJP5 has no effect on platelet aggregation mediated by fibrinogen binding to GPIIb/IIIa. Two patients gave their informed consent to receiving infusion of 1-desamino-8-D-arginine vasopressin (DDAVP), a vasopressin analogue known to raise the vWF levels in plasma by two- to fourfold. The bleeding time, measured before and 45 min after infusion, shortened from greater than 24 min to 12 min and 50 s in one patient and from 16 min to 9 min and 30 s in the other. Concurrently, the rate and extent of ADP-induced platelet aggregation improved after DDAVP infusion. The pattern, however, reversed to baseline levels within 4 h. The concentration of plasma vWF increased after DDAVP infusion, but that of fibrinogen remained at trace levels. We conclude that vWF interaction with GPIIb/IIIa mediates platelet-platelet interaction and may play a role in primary hemostasis.