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.

Drug-Induced Thrombophilic or Prothrombotic States: An Underestimated Clinical Problem That Involves Both Legal and Illegal Compounds.

Vascular thrombosis, both arterial and venous, is a condition associated with significant morbidity and mortality. There are multiple risk factors for thrombosis, both congenital and acquired, and in the majority of cases, these risk factors are not modifiable. Over the past 2 decades, multiple drugs (both illegal and legal) have been associated with increased risk of thrombosis. However, due to limited scientific literature regarding the prothrombotic tendencies of these drugs, there is a concomitant limited understanding of the pathophysiology of drug-induced thrombosis. As drugs are one of the few modifiable risk factors for thrombosis, further study and dissemination of knowledge regarding drug-associated and drug-induced thrombosis are essential and have the potential to lead to decreased future incidence of thrombosis. The mechanisms at the basis of the thrombophilic activity of these drugs are variable and sometimes still ill recognized. Increased levels of clotting factors, reduction in coagulation natural inhibitors, decreased fibrinolysis, activated clotting factors, increased blood viscosity, endothelial damage, and increased platelet number and activation are the most frequent causes. Arterial steal or coronary arteries no flow has also been implicated. In some cases due to the intake of several drugs, more than one mechanism is present in a given patient. The purpose of the present review is to analyze all the drugs demonstrated to be potentially thrombotic. It is hoped that a prudent use or nonuse of these drugs might result in a reduction of thrombosis-associated diseases.

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.

Congenital factor XI and factor VII deficiencies assure an apparent opposite protection against arterial or venous thrombosis: An intriguing observation.

OBJECTIVE: To investigate the prevalence and type of thrombotic events reported in patients with congenital factor XI (FXI) or factor VII (FVII) deficiency. PATIENTS AND METHODS: Data on all patients with congenital FXI or FVII deficiency and a thrombotic event were gathered by means of a time unlimited PubMed search carried out in June 2014 and in February 2015. Appropriate keywords including the medical subject headings were used in both instances. Side tables were also consulted and cross-checking of the references was carried out to avoid omissions. The thrombosis event had to be proven by objective methods. RESULTS: Forty-three patients with FXI deficiency had arterial thrombosis and only eight had venous thrombosis. On the contrary, only five patients with FVII deficiency had arterial thrombosis whereas 31 patients had venous thrombosis. The arterial/venous ratios were 5.37 and 0.17 for FXI or FVII, respectively. CONCLUSIONS: Arterial thrombosis is frequent in FXI deficiency whereas venous thrombosis is rare. The reverse is true for FVII deficiency. The significance of these findings is discussed especially in view of the recent use of synthetic anti-FXI compounds in the prophylaxis of post-orthopedic surgery of venous thrombosis complications.

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.

Eating quality of beef from free-range and confined Podolian young bulls.

The purpose of the present study was to assess the effect of grazing on meat quality of young Podolian bulls by using 6 free-ranging (FR) and 6 confined (CON) animals slaughtered at 18 mo of age (Exp. 1). A second experiment (Exp. 2) was performed the subsequent year where the age at slaughter was 15 mo of age (6 animals/group). Quantitative descriptive sensory analysis, water-holding capacity (WHC; thawing, centrifugation, and cooking losses), and shear force (only in Exp. 2) were evaluated on LM, aged 8 d. Both experiments showed that CON animals produced beef with greater overall beef flavor (P < 0.01 and P < 0.05 in Exp. 1 and 2, respectively) and odor intensities (P < 0.10 and P < 0.05 in Exp. and 1 and 2, respectively) and increased malondialdehyde contents (P < 0.01 and P < 0.05 in Exp. 1 and 2, respectively). In Exp. 2 beef from FR bulls showed higher sensory tenderness as compared with CON bulls (P < 0.05) and a lower shear force (P < 0.05). In Exp. 1, beef obtained from FR bulls showed lower centrifugation and greater thawing losses compared with samples from bulls from group CON (P < 0.05) whereas rearing system did not affect any WHC variables in Exp. 2. The results obtained from the 2 experiments were generally consistent. The different results occasionally observed (e.g., sensory tenderness and WHC) is attributed to the different ages at slaughter used in the 2 experiments (18 and 15 mo). In particular, at an earlier age at slaughter (15 mo) the effect of FR on meat quality was beneficial on sensory tenderness and mechanical properties. Therefore, given the additional costs of maintaining the bulls for another 3 mo when slaughtered at 18 mo of age, a reduced age at slaughter of FR bulls may be suggested to avoid the decrement of herbage mass availability inducing the consumption of high amounts of concentrate.

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.

Congenital FVII deficiency and pulmonary embolism: a critical appraisal of all reported cases.

Fourteen patients with congenital factor VII (FVII) deficiency were reported to have had pulmonary embolism. All patients were type 2 defects with variably low activity but normal or near-normal antigen. Concomitant deep vein thrombosis was present in 7 instances. The majority of patients had no or only a mild bleeding tendency. Associated prothrombotic risk factors were present in 11 patients (old age, surgery, substitution therapy with prothrombin complex, plasma-derived or activated FVII concentrates). Pulmonary embolism was usually moderate or severe. In 2 cases, it was fatal. Only 4 patients were studied by means of molecular biology techniques. The Arg304Gln mutation was found in 5 of the 8 alleles. Heparin and Coumadin together with adequate substitution therapy were carried out in 5 patients with satisfactory results. The FVII deficiency does not grant a sure protection from venous thromboembolism.

Homozygous FVII deficiencies with different reactivity towards tissue thromboplastins of different origin.

The reagents most frequently used for FVII activity assay are obtained by rabbit brain or human placenta. In recent years, human recombinant thromboplastins have received great attention. FVII activity in FVII deficiency is usually low, regardless of the thromboplastin used. There are a few exceptions to this rule. These are represented by FVII Padua (Arg304Gln), FVII Nagoya (Arg304Trp), and FVII (Arg79Gln). In these three instances, clear discrepancies were noted in the FVII activity depending on the thromboplastin used. This indicates that at least two areas of FVII are involved in tissue binding, namely an epidermal growth factor domain of the light chain (Arg79Gln) and the catalytic domain (Arg304), controlled by exons 4 and 8, respectively. Since these three variants are cross reactive material positive, namely they are Type 2 defects, all other variants with normal antigen should be investigated by a panel of at least three tissue thromboplastins (rabbit brain, human tissue or human recombinant, and ox brain derived) in order to obtain a satisfactory classification.

Activated FVII levels in factor VII Padua (Arg304Gln) coagulation disorder and in true factor VII deficiency: a study in homozygotes and heterozygotes.

Congenital FVII deficiency is usually subdivided into two forms: type I and type II. Type I is characterized by a concomitant deficiency of FVII activity and FVII antigen (true deficiency). Type II is characterized by a discrepancy between FVII activity which is always low and FVII antigen which may be normal, near normal, or reduced. Thromboplastins of different origins may show a discrepant behaviour towards type II FVII deficiencies. The abnormal factor VII present in these forms may, in fact show, different levels of activity, according to the thromboplastin used in the assay system. Typical of these variants is the Arg304Gln mutation (know as FVII Padua). In this variant, FVII level is low when rabbit brain thromboplastin is used, whereas the level is perfectly normal when ox-brain thromboplastin is employed. Intermediate levels are obtained if human placenta or human recombinant is used. Since ox-brain thromboplastin is very sensitive to activated FVII, the normal FVII levels obtained in FVII Padua could be due to abnormally high circulating levels of activated FVII. The purpose of the present paper was to investigate the level of activated FVII present in homozygotes and heterozygotes with FVII Padua. For comparison, a group of patients with type I or 'true' deficiency was also investigated. A group of 21 normal patients served as controls. The activated FVII level found in FVII Padua was 8·4 and 41·0 mU/ml for homozygotes and heterozygotes, respectively. The level found in homozygous true deficiency was unassayable, whereas that found in heterozygotes was 36·2 mU/ml. The level found in the control population was 64·9 mU/ml in agreement with other reports. The low levels of activated FVIIa found in homozygotes with FVII Padua indicate that the normal FVII activity found with ox-brain thromboplastin cannot be attributed to higher than normal circulating levels of FVIIa.

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.

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.

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.

Podolian beef production on pasture and in confinement.

From February to August 2007 the effect of rearing system (confined (C) v. free ranging (FR)) and season (spring v. summer) was evaluated on behaviour, immune and blood parameters and beef production (experiment 1). From February to August 2008, the effect of rearing system was only evaluated on beef production (experiment 2). A total of 12 Podolian young bulls were used each year. They were slaughtered at 18 and 15 months of age in 2007 and 2008, respectively. Herbage mass and pasture composition were monitored during the 2 years. Pasture availability, in terms of herbage mass and composition, as well as its seasonal development, was similar in the 2 years. In the first experiment, FR animals spent more time walking (P < 0.05), feeding (P < 0.001) and standing (P < 0.01) and showed a lower number of agonistic (P < 0.05) and non-agonistic social interaction than C animals (P < 0.01). Significant lower concentrations of serum urea nitrogen (P < 0.001) and creatinine (P < 0.10) in FR animals indicated a lower protein nutritional status due to inadequate protein availability at pasture. As a consequence, average daily gains (P < 0.05), slaughter weight (P < 0.05) and body condition score (P < 0.01) were lower in grazing animals as compared with C bulls. Cellular immune responsiveness was higher in FR animals (P < 0.05). Similarly, antibody titre to keyhole limpet hemocyanin was higher in FR bulls at the 2nd and 3rd month after antigen injection (P < 0.05), whereas it tended to be higher at the 4th month (P < 0.10). In both experiments, grazing negatively affected meat colour in terms of lightness. Eighteen-month-old bulls also showed lower final weight, weight gain and body conditions when kept outdoor: a possible consequence of nutrient deficits, as suggested by the metabolic status of FR animals. The same animals, however, benefited from FR in terms of natural behaviour expression and immune responsiveness. When the experiment was replicated the subsequent year, on animals slaughtered at 15 months of age, no differences between the performances of FR and C animals were detected. The earlier slaughter age system was also proportionally less dependent on external inputs as grazing was not extended to the dry season when herbage mass availability was lower.

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.