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Prolonged thromboplastin time but normal partial thromboplastin time in coagulation analysis lead to the diagnosis of factor VII-deficiency. The different forms of congenital and acquired factor VII-deficiency and the appropriate therapies are discussed, especially with regard to the recently available factor VII preparation.
A radioimmunoassay (RIA) for factor VII was developed using 125I-factor VII, anti-factor VII rabbit serum and anti-rabbit IgG goat serum. The lower limit of sensitivity in normal reference plasma was 3 X 10(-3) units/ml. Although the level of factor VII antigen (VII:Ag) in normal plasma samples (n = 20) 0.944 +/- 0.176 units/ml, correlated with that of factor VII coagulant activity (r = 0.89), VII:Ag level in paired normal sera showed a higher value (1.469 +/- 0.376 units/ml). The level of antigen according to RIA of factor VIIa activated by factor Xa increased 2.5-fold compared with that of unactivated factor VII. It is suggested that the polyclonal anti-factor VII produced in a rabbit had higher affinity for factor VIIa than for factor VII. In two out of seven patients with congenital factor VII deficiency, VII:Ag was detectable (0.04, 0.31 units/ml, respectively) whereas VII:C was less than 0.01 units/ml. In 12 warfarin-treated individuals, VII:C showed a lower level (0.121 +/- 0.063 units/ml) that that of VII:Ag (0.518 +/- 0.186 units/ml). During 4 weeks observation after stopping warfarin, VII:C and VII:Ag reached normal levels in 1 week. However, VII:C did not reach equivalence with VII:Ag until 4 weeks had elapsed.
Authors report a four month old patient, admitted to hospital because of blood in stools. Diagnosis of congenital deficiency of factor VII was established because such factor was practically absent; on the contrary, other coagulation factors were normal. His parents and sister presented a mild deficit of factor VII without clinical manifestations. An up-to date review of the problem is presented.
The effect of both congenital and acquired factor VII deficiency on the cuticle bleeding time (CBT) was evaluated in dogs. The CBT has been previously documented to be a sensitive indicator of factor VIII:C deficiency in hemophilic dogs. Serial CBT determinations were made on normal dogs treated with high-dose warfarin. At 48 hours post-treatment, the CBT was normal, although the factor VII level was less than 1%, whereas the levels of factors II, IX, and X were 44%, 25%, and 17%, respectively. At 120 hours the CBT became abnormal when all vitamin K-dependent clotting factors had dropped to less than 18%. Administration of a plasma concentrate of factors II, IX, and X corrected the CBT, despite the factor VII level remaining at less than 1%. Similar studies in a congenitally factor VII-deficient dog (factor VII less than 2%) confirmed that this deficiency state was not associated with an abnormality of the CBT. Administration of heparin to both normal and factor VII-deficient animals was associated with prolongation of the CBT, but the heparin dose required in the normal animals was substantially higher than in the factor VII-deficient animals. These data do not suggest that factor VII/VIIa has an exclusive role in generating factor Xa, either directly or indirectly, by way of factor IXa generation, in vivo. However, the increase in heparin sensitivity of the factor VII-deficient animals does suggest that factor VII/VIIa may, in some circumstances, present a significant alternative pathway of factor X activation, although the activation pathway involved cannot be determined from the studies performed.
FVII deficiency is a rather rare inherited hemocoagulation disorder that predisposes to hemorrhagic events, especially from mucous membranes, that are not predictable and severe as in hemophilia A. This defect produces prolonged prothrombin time (PT), reduced activity of FVII and normal activated partial thromboplastin time (aPTT). We report the case of a 43-year-old obese woman with severe deficiency of factor VII (FVII), probably genetic in nature, and meno-metrorrhagia associated with multiple fibromas of uterus. Our patient had no history of bleeding in infancy and young age, and in the past, before the disease was diagnosed, underwent major surgery operations (thyroidectomy and caesarian section) without hemorrhage. Patient's relatives with mild heterozygous deficiency of FVII (the father, a brother, a sister, a sister's daughter and the patient's son) did not show any bleeding tendency. This case report is discussed in the light of literature data ((source: Medline from 1964 to 1996). The different forms of congenital (isolated or combined with other clotting disorders) and acquired FVII deficiency, with the appropriate therapies, are reviewed. The clinician must consider FVII deficiency in cases of recurrent bleeding, and this disease, even if rather rare, should not be underestimated in clinical practice because it is potentially fatal.
A family with inherited factor VII deficiency is described. The propositus is a 9-year-old girl with chronic haemorrhagic history of epistaxis and bleeding after tooth extractions. Her factor VII coagulant activity was less than 3% using rabbit thromboplastin. She had a factor VII antigen level of 50%. Both parents were heterozygous for factor VII deficiency. The father had procoagulant factor VII (VII-C) of 44% and factor VII antigen (VII-Ag) of 74%, and the mother had 54% of factor VII-C and 85% of VII-Ag. Her only brother had normal levels of factor VII-C (100%). Additionally, some abnormalities in the fibrinolytic system were detected both in the propositus and her brother with shortened euglobulin lysis times and increased functional levels of plasminogen activator. To our knowledge, the clinical association of inherited factor VII deficiency and familial fibrinolytic disturbances has not been described so far.
Prolonged prothrombin time in the blood coagulation test was seen in some beagle dogs whose activated partial prothrombin times were distributed within the normal range. This phenomenon suggested possible abnormalities in coagulation factors II, V, VII, and/or X. Therefore, a revised cross-matching test was given and a determination of coagulation factors related to the extrinsic system was performed. We also determined whether or not factor VII inhibitor was present. The results were as follows: 1) In the revised cross-matching test, the prolonged prothrombin times were revised when normal canine serum was added to the plasma that showed prolongation of prothrombin time, but not when pooled normal canine plasma absorbed with BaSO4 was added to it. 2) The level of factor VII in the plasma with prolonged prothrombin time was 5 approximately 10% of the level in normal canine plasma. 3) Factor VII inhibitor was not detected in the plasma with prolonged prothrombin time or in normal plasma. Consequently, the prolongation of prothrombin time was attributed to a deficiency in factor VII. This abnormality was confirmed to be congenital.
BACKGROUND: Combined deficiency of vitamin K-dependent coagulation factors (II, VII, IX, X) is an uncommon challenge for the expectant gravida. CASE: A 34-year-old primigravida had congenital combined deficiency of factors II, VII, IX, and X that were incompletely sensitive to vitamin K. She had an altered form of vitamin K-dependent factors that retained immunologic activity but lacked coagulant activity and the normal complement of gamma-carboxyglutamic acid residues. She required vitamin K supplementation throughout her life. After an uneventful pregnancy she had postpartum hemorrhage resulting from an episiotomy. Fresh frozen plasma was administered to achieve hemostasis. The remainder of her postpartum course was normal. CONCLUSION: Combined congenital deficiency of factors II, VII, IX, and X can be managed in pregnancy with the use of vitamin K and fresh frozen plasma.
Factor VII activity (FVIIc), a risk marker for coronary heart disease, is increased during postprandial lipemia. Factor VII activation accompanies lipolysis of triglyceride-rich lipoproteins, but the nature of this association and whether it is causal remain uncertain. To explore this issue, four patients with homozygous factor XII deficiency, four with complete factor XI deficiency, six with factor IX deficiency, and their respective age- and sex-matched controls were given two isocaloric dietary regimens, one providing on average 136 g fat and the other 19 g fat. Blood was taken before breakfast, immediately before lunch at 195 minutes, and at completion of the study at 390 minutes. All samples for each subject and matched control were assayed as one batch for FVIIc, activated factor VII, and factor VII antigen (FVIIag). Activation of factor VII was observed with the high-fat regimen but not with the low-fat regimen in all controls, factor XII-deficient patients, and factor XI-deficient patients. No factor VII activation was observed during either regimen in factor IX-deficient patients, but a normal postprandial responsiveness of factor VII to dietary fat was restored in one patient who replicated the study after factor IX therapy. Plasma FVIIag was not altered postprandially in either regimen in any group of patients or controls. Factor IX apparently plays an obligatory role in the postprandial activation of factor VII, although the mechanism remains to be determined.
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We studied African-American Factor (FVII)-deficient variants and carriers in Georgia by measuring their levels of FVII antigen (FVIIAG) and FVII procoagulant (FVIIC). Factor VIIAG was determined using enzyme-linked immunoassay (ELISA), whereas FVIIC was measured in two ways: 1) by fibrin clotting methods that employed human recombinant (HRFVIIC), human placental (HPFVIIC), rabbit brain (RBFVIIC), and bovine brain (BBFVIIC) thromboplastins; and 2) by an amidolytic method (AMFVIIC). Prothrombin time tests (PT) were also performed by standard methods. These 4 FVII-deficient patients and 3 carriers demonstrated the following results: PT: 18.2 +/- 6.5 sec; FVIIAG: 73.0 +/- 14.9%; HRFVIIC: 30.6 +/- 20.3%; HPFVIIC: 30.5 +/- 21.4%; RBFVIIC: 25.3 +/- 21.4%; BBFVIIC: 30.6 +/- 17.5%; AMFVIIC: 44.1 +/- 18.3%. We conclude that a group of clinically mild African-American FVII-deficient variants exists in Georgia. This group is characterized by the presence of FVIIAG and decreased FVIIC, using a variety of thromboplastins; and excellent correlation was noted for both human thromboplastins.
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In inherited disorders transmitted as autosomal recessive traits the children of affected individuals are usually asymptomatic and phenotypically normal because they are heterozygous for the defect. In an Iranian Jewish family with moderately severe deficiency of coagulation factor VII (an autosomal recessive bleeding disorder) the son of an affected woman was also affected. DNA analysis of the factor VII gene showed that this unusual situation was due to the fact that he inherited an abnormal allele with the Ala244Val missense mutation from both the homozygous mother and the heterozygous father. The parents, although not overtly consanguineous, belong to the same ethnic group of Iranian Jews, among whom this factor VII gene mutation reaches high frequencies (between 2 and 3%) in the heterozygous state.
A study has been made of the rate of disappearance of factor VIII during the clotting of normal plasma samples and of samples deficient in factors V, VII, IX, X, XI and XII. The rate of disappearance (or consumption) of factor VIII was the same in the normal and factor VII deficient samples. Delayed disappearance of factor VIII was observed in samples deficient in factors V, IX, X, XI and XII. The significance of the findings to the theory of blood coagulation is discussed.
We report the case of an 8-year-old boy with no prior abnormal bleeding history who presented with severe central abdominal pain following a freak accident at a local ice rink. Clinical examination confirmed a tender periumbilical mass. An ultrasound scan confirmed a large haemorrhagic fluid collection adjacent to the second part of his duodenum that was causing a subacute small-bowel obstruction. He was found to have a persistently prolonged prothrombin time between 17.3 and 18.1 s but normal liver function tests. There was no suggestion of dietary vitamin K deficiency. Further investigations confirmed factor VII deficiency with levels between 30.4 and 33.6 IU dL-1. His prothrombin time did not normalize with intravenous vitamin K. He was subsequently treated with three 30 microg kg-1 body weight doses of novoseven at 4-h interval and made an excellent recovery. The haematoma virtually resolved completely confirmed by a follow-up ultrasound scan 3 months after the initial event.
A few neonates born to mothers receiving anticonvulsant drugs during pregnancy have shown defects in vitamin K dependent clotting factors with or without clinical bleeding. Experimentally, phenytoin (diphenyl hydantoin, DPH) has induced clotting defects in cats and inhibited production of clotting factors in rat liver slices. Phenobarbital has produced similar but milder defects. Anticonvulsants have been observed to produce clotting defects in 9 children, 2 weeks to 8 years in age. Elevated levels of phenytoin or other anticonvulsants, or a combination of anticonvulsants were measured in the children. Six patients were on drug combination including two or more of the following: phenytoin, phenobarbital, primidone, carbamazepine, diazepam, ethosuximide. Clotting defects included: elevated prothrombin time, elevated partial thromboplastin time, diminished factors V, VII or X. All children had neurologic symptoms of anticonvulsant toxicity, but the only hematologic problems were oozing from venipuncture sites and increased bruising in 3. All patients were on normal diets and had normal liver function tests. By lowering the level of anticonvulsants, clotting factors returned toward normal. Elevated levels of anticonvulsants can potentially produce clotting defects in neonates and young children.
OBJECTIVE: To optimize a prothrombin time (PT) method designed for human plasma for use with canine plasma. SAMPLE POPULATION: 100 plasma samples from healthy dogs and 50 plasma samples with reduced activity of the single factors II, V, VII or X. PROCEDURE: Canine plasma samples with various coagulation activity values (100, 75, 50, 25 and 10%: prepared by dilution from a plasma pool [n = 100]) were assayed at various sample dilutions and dilutions of the thromboplastin component of 3 commercial calcium thromboplastin reagents. The sc-named optimized PT test was compared with the standard test with respect to its sensitivity and correlation with the sum of the activity decreases of single factors II, V, VII, and X in relation to the respective reference range. RESULTS: The time intervals between various coagulation activity values, which were small by use of the standard test, could be increased by diluting the sample and substituting fibrinogen, but not by diluting the tissue thromboplastin component of PT reagent. On the basis of 50 abnormal plasma samples, the optimized test had high sensitivity (0.90 to 1.00, dependent on reagent and sample dilution) in contrast to the standard test, which had low sensitivity (0.24 to 0.58, dependent on reagent). Also, correlation with the sum of the activity decreases was closer by use of the optimized (0.90 to 0.93) than the standard (0.58 to 0.84) test. CONCLUSIONS: In contrast to the standard test, an optimized test is suitable as a sensitive screening test of the extrinsic coagulation system in dogs. CLINICAL RELEVANCE: The optimized PT method is easy to perform and, therefore, should be in general use for assay of canine plasma.
Congenital deficiency of coagulation factor VII is a rare autosomal and usually recessive genetic bleeding disorder which has been discovered in an Icelandic family. The propositus is a male who experienced intermittent painful inflammation of his ankle joints at the age of 9-10 and later also in his knees, elbow, shoulder, and wrist. Smaller joints were spared, serologies for rheumatoid disease were negative. He was treated for rheumatoid arthritis with limited results and became practically invalid due to his arthritis at the age of 40. At the age of 57, a surgical synovectomy of his knee joint was complicated by postoperative bleeding, and signs of chronic haemorrhagic arthritis were noted in the synovia. Subsequently, a marked prolongation of his prothrombin time and a near total deficiency of coagulation factor VII were discovered. All of his nine siblings were deficient in coagulation factor VII, three of them markedly deficient like the proband and six moderetely deficient. The pattern of inheritance suggests that one of their parents was heterozygous and the other homozygous or doubly heterozygous of genetic deficiency of coagulation factor VII. The parents were second cousins. Of the siblings, only the propositus had a bleeding tendency or arthritis. No evidence of such symptoms in their parents or grandparents was found. This family is the only Icelandic family with congenital deficiency of coagulation factor VII known to the authors.