Vitamin K-Dependent Coagulation Factors That May be Responsible for Both Bleeding and Thrombosis (FII, FVII, and FIX)

Vitamin K-dependent clotting factors are commonly divided into prohemorrhagic (FII, FVII, FIX, and FX) and antithrombotic (protein C and protein S). Furthermore, another protein (protein Z) does not seem strictly correlated with blood clotting. As a consequence of this assumption, vitamin K-dependent defects were considered as hemorrhagic or thrombotic disorders. Recent clinical observations, and especially, recent advances in molecular biology investigations, have demonstrated that this was incorrect. In 2009, it was demonstrated that the mutation Arg338Leu in exon 8 of FIX was associated with the appearance of a thrombophilic state and venous thrombosis. The defect was characterized by a 10-fold increased activity in FIX activity, while FIX antigen was only slightly increased (FIX Padua). On the other hand, it was noted on clinical grounds that the thrombosis, mainly venous, was present in about 2% to 3% of patients with FVII deficiency. It was subsequently demonstrated that 2 mutations in FVII, namely, Arg304Gln and Ala294Val, were particularly affected. Both these mutations are type 2 defects, namely, they show low activity but normal or near-normal FVII antigen. More recently, in 2011-2012, it was noted that prothrombin defects due to mutations of Arg596 to Leu, Gln, or Trp in exon 15 cause the appearance of a dysprothrombinemia that shows no bleeding tendency but instead a prothrombotic state with venous thrombosis. On the contrary, no abnormality of protein C or protein S has been shown to be associated with bleeding rather than with thrombosis. These studies have considerably widened the spectrum and significance of blood coagulation studies

Peculiar, poorly known, rare congenital bleeding disorders presenting thrombotic events: an understudied chapter of molecular, blood coagulation defects

Very rare, peculiar congenital bleeding disorders are usually dealt with in clinics without giving much importance. We think that this practice is not correct since the disorders may often provide useful information about blood coagulation. In this review, we assess very rare bleeding conditions. We refer to the defects of the fibrinolytic system, alpha 1-antitrypsin Pittsburg, few dysprothrombinemias, east Texas or short FV defect, FIX Padua, and thrombomodulin (TM) abnormality. These defects are usually not included in rare bleeding disorders. Patients were gathered from two sources: personal files and two time-unlimited PubMed searches carried out on February 2010 and July 2019. Combined defects were disregarded. These rare bleeding conditions are often unrecognized even though some of them, such as antiplasmin deficiency, are not that rare with more than 30 cases reported already. The underevaluation of the fibrinolytic defects is due to the decrease in the use of methods capable of detecting increased fibrinolysis in routine laboratory study. The limited use of immunological tests represents a second drawback as in the dysprothrombinemia, east Texas Factor V, and FIX Padua. Finally, the limited use of assays of natural inhibitors such as tissue factor pathway inhibitor and TM has played a role in delaying east Texas FX recognition and TM defect. The study of rare, peculiar bleeding disorders has been very important in clarifying the nature of the defects, and it has even allowed the identification of mutations that may turn them from prohemorrhagic to prothrombotic in some of these proteins. This has greatly contributed to the understanding of the complex relationship existing among clotting defects. [JBCGenetics 2020; 3(2.000): 84-93

Acquired Isolated FVII Deficiency An Underestimated and Potentially Important Laboratory Finding.

Objective: To investigate all cases of isolated factor VII (FVII) deficiency as gathered from personal files or by a PubMed search. Patients and Methods: Personal files dealing with patients studied in Padua during the years 1970 to 2010 were reevaluated. The PubMed search was time unlimited and was carried on 2 occasions during 2014. Cross-checking of the references, listed in every article, was also carried out to avoid omissions. Inclusion criteria were isolated FVII defect of less than 40% of normal, negative coagulation pattern in the family, normal level of other vitamin K-dependent clotting factors, and normalization of the clotting factor after the therapeutic procedures, unless the patient died. Results: Twenty-nine patients met the inclusion criteria (18 male and 9 female, in 2 cases gender was unreported). This number included 1 personal case. Mean age was 37.9 (range 3-80). Underlying diseases were the following: neoplasia, infections, polytrauma, penicillin administration, nephrotic syndrome Wiskott Aldrich syndrome, and left heart failure (1 case, each); 2 patients had no underlying disease. Bleeding was variable but usually mild. There were 11 fatalities. Conclusions: Isolated FVII deficiency is a rare defect, which appears to be a finding associated with several morbid conditions, especially sepsis and tumors. This indicates the need for a careful investigation of even a mild prolongation of prothrombin time, especially when fibrinogen and partial thromboplastin time are normal

The story of serum prothrombin conversion accelerator, proconvertin, stable factor, cothromboplastin, prothrombin accelerator or autoprothrombin I, and their subsequent merging into factor VII

Factor VII (FVII) deficiency is one of the two congenital coagulation disorders that was not discovered by the description of a new bleeding patient whose clotting pattern did not fit the blood coagulation knowledge of the time (the other is factor XIII deficiency). The existence of an additional factor capable of accelerating the conversion of prothrombin into thrombin was suspected before 1951, the year in which the first family with FVII deficiency was discovered. As several investigators were involved in the discovery of FVII deficiency from both sides of the Atlantic, several different names were tentatively suggested to define this entity, namely stable factor (in contrast with labile factor or FV), cothromboplastin, proconvertin, serum prothrombin conversion accelerator, prothrombin acceleration, and autoprothrombin I. The last term was proposed by those who denied the existence of this new entity, which was instead considered to be a derivate of prothrombin activation, namely autoprothrombin. The description of several families, from all over the world, of the same defect, however clearly demonstrated the singularity of the condition. Factor VII was then proposed to define this protein. In subsequent years, several variants were described with peculiar reactivity toward tissue thromboplastins of different origin. Molecular biology techniques demonstrated several gene mutations, usually missense mutations, often involving exon 8 of the FVII gene. Later studies dealt with the relation of FVII with tissue factor and activated FVII (FVIIa). The evaluation of circulating FVIIa was made possible by the use of a truncated form of tissue factor, which is only sensitive to FVIIa present in the circulation. The development of FVII concentrates, both plasma derived and recombinant, has facilitated therapeutic management of FVII-deficient patients. The use of FVIIa concentrates was noted to be associated with the occasional occurrence of thrombotic events, mainly venous. Total or partial liver transplants have been performed with success in these patients and have \u201ccured\u201d their deficiencies. Prenatal diagnosis has also been performed and recent research involves the development of inhibitors of FVII\u2009+\u2009tissue factor complex or of FVIIa. This approach, if successful, could provide another antithrombotic therapeutics tool. The story of FVII well summarizes the efforts of both theoretical and clinical approaches in the characterization of a coagulation disorder, that is, among the rare bleeding conditions, most frequently encountered in clinical practice

Structural and Thermodynamic Analysis of HIV-1 Fusion Inhibition Using Small gp41 Mimetic Proteins

Development of effective inhibitors of the fusion between HIV-1 and the host cell membrane mediated by gp41 continues to be a grand challenge due to an incomplete understanding of the molecular and mechanistic details of the fusion process. We previously developed single-chain, chimeric proteins (named covNHR) that accurately mimic the N-heptad repeat (NHR) region of gp41 in a highly stable coiled-coil conformation. These molecules bind strongly to peptides derived from the gp41 C-heptad repeat (CHR) and are potent and broad HIV-1 inhibitors. Here, we investigated two covNHR variants differing in two mutations, V10E and Q123R (equivalent to V38E and Q40R in gp41 sequence) that reproduce the effect of HIV-1 mutations associated with resistance to fusion inhibitors, such as T20 (enfuvirtide). A detailed calorimetric analysis of the binding between the covNHR proteins and CHR peptides (C34 and T20) reveals drastic changes in affinity due to the mutations as a result of local changes in interactions at the site of T20 resistance. The crystallographic structure of the covNHR:C34 complex shows a virtually identical CHR–NHR binding interface to that of the post-fusion structure of gp41 and underlines an important role of buried interfacial water molecules in binding affinity and in development of resistance against CHR peptides. Despite the great difference in affinity, both covNHR variants demonstrate strong inhibitory activity for a wide variety of HIV-1 strains. These properties support the high potential of these covNHR proteins as new potent HIV-1 inhibitors. Our results may guide future inhibition approaches.Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, SpainMinisterio de Economía y Competitividad (grants BIO2016-76640-R and BIO2016-78020-R) y Fondo Europeo para el Desarrollo Regional (FEDER) de la Unión EuropeaANRS and the Vaccine Research Institute for the Investissements d'Avenir program managed by the ANR under reference ANR-10-LABX-7

Effect of busulfan on JAK2V617F allele burden.

not all patients who had undergone BU therapy have a significant decrease in JAK2V617F allele burde

Prevalence and Causes of Anemia in Hospitalized Patients: Impact on Diseases Outcome

Anemia is extremely common in hospitalized patients who are old and often with multiple diseases. We evaluated 435 consecutive patients admitted in the internal medicine department of a hub hospital and 191 (43.9%) of them were anemic. Demographic, historic and clinical data, laboratory tests, duration of hospitalization, re-admission at 30 days and death were recorded. Patients were stratified by age (80 years), anemia severity, and etiology of anemia. The causes of anemia were: iron deficiency in 28 patients, vitamin B12 and folic acid deficiencies in 6, chronic inflammatory diseases in 80, chronic kidney disease in 15, and multifactorial in 62. The severity of the clinical picture at admission was significantly worse (p < 0.001), length of hospitalization was longer (p < 0.001) and inversely correlated to the Hb concentration, re-admissions and deaths were more frequent (p 0.017) in anemic compared to non-anemic patients. A specific treatment for anemia was used in 99 patients (36.6%) (transfusions, erythropoietin, iron, vitamin B12 and/or folic acid). Anemia (and/or its treatment) was red in the discharge letter only 54 patients. Even if anemia is common, in internal medicine departments scarce attention is paid to it, as it is generally considered a "minor" problem, particularly in older patients often affected by multiple pathologies. Our data indicate the need of renewed medical attention to anemia, as it may positively affect the outcome of several concurrent medical conditions and the multidimensional loss of function in older hospitalized patients