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Results for “Factor XI Deficiency”

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PubMed1983

Hemorrhage in a cat caused by inhibition of factor XI (plasma thromboplastin antecedent).

A coagulation profile from a 5-year-old neutered male cat with severe epistaxis revealed an intrinsic coagulation defect characterized by prolonged activated partial thromboplastin time, with normal bleeding time, platelet count, and prothrombin time. Subsequent factor XI analyses, using bovine factor XI-deficient plasma, revealed factor XI deficiency. Hematologic and clinical studies on the cat failed to reveal an underlying disease process that might have resulted in acquired factor XI inhibition.

Animals↗
PubMed1990

Characterization of a panel of monoclonal antibodies to human coagulation factor XI and detection of factor XI in Hep G2 cell conditioned medium.

We have produced a panel of ten monoclonal antibodies specific to coagulation factor XI. Western blot analysis demonstrates that 9 of these antibodies react with the heavy chain of factor XI and one with the light chain. Seven of these antibodies inhibit factor XI and factor XIa activity. We have used immobilised monoclonal antibody for the production of factor XI deficient plasma and to purify factor XI to homogeneity with high yield in a simple two-step procedure. These monoclonal antibodies were used to develop highly sensitive immunoassays capable of detecting less than 0.01 mu factor XI antigen ml-1. A strong correlation was found between antigen and activity levels in 11 patients with hereditary deficiency indicating that none was cross-reacting material positive. Cultured Hep G2 cells were found to synthesize small amounts of factor XI antigen and this could also be detected by functional assay and by western blot analysis.

Animals↗
PubMed1984

The possible role of platelets in bypassing the contact phase of blood coagulation.

Data presented herein and previously support an active role for platelets in promoting the interaction and activation of the coagulation proteins of the contact phase of intrinsic coagulation. The platelet membrane, activated by ADP collagen or thrombin, can promote the proteolytic activation of factor XII to factor XIIa in the presence of kallikrein and high molecular weight kininogen. The zymogen factor XI associates with high molecular weight kininogen in plasma and becomes bound to a site on the membrane of thrombin or collagen activated platelets. Thereafter, platelet bound factor XI can be proteolytically activated to factor XIa either in the presence of factor XIIa or in the presence of kallikrein. These observations could explain the absence of bleeding complications in patients with factor XII deficiency. In addition, platelets contain a molecule which has a higher molecular weight than plasma factor XI and possibly consists of a tetramer of four identical subunits of 52000 daltons each of which is functionally and immunologically similar to plasma factor XI. Since this molecule is present in the platelets of patients with severe plasma factor XI deficiency and no evidence of bleeding, we postulate that platelet factor XI can substitute for plasma factor XI in hemostasis and possibly account for the considerable variability in clinical severity observed in patients with factor XI deficiency.

Blood Coagulation↗
PubMed1988

Cardiovascular surgery in patients with congenital plasma coagulopathies.

From 1978 to 1986, fifteen cardiovascular operations were performed on 13 patients with known congenital bleeding disorders. The patients (10 men and 3 women) had a mean age of 51.1 +/- 3.4 years. Four were seen with cardiovascular lesions and documented hemophilia A (Factor VIII deficiency); 3 had hemophilia B (Factor IX deficiency); 3 had Factor XI deficiency; 2 had von Willebrand's disease, and 1 had dysfibrinogenemia. All patients had a history of major hemorrhage after dental extractions or general surgical procedures, and had clearly documented coagulation disorders on hematological evaluation. Elective cardiovascular procedures performed in these patients included aortocoronary bypass grafting (eight), cardiac valve replacement or repair (five), aortic graft placement (one), and carotid endarterectomy (one). The mainstay of perioperative management included appropriate replacement therapy with blood components. Coagulation factor levels were measured routinely to guide therapy. There were no deaths. Two hemorrhagic complications necessitated reexploration. We conclude that in patients known to have congenital coagulation disorders, cardiovascular operations using systemic heparinization can be performed with minimal morbidity and mortality when carried out with preoperative and perioperative support from the hematology service, adequate replacement therapy using blood components, and careful monitoring of the coagulation status.

Afibrinogenemia↗
PubMed1997

Comparison of in vitro function of neutrophils from cattle deficient in plasma factor XI activity and from normal animals.

Cattle, homozygous for the genetic disorder of factor XI (FXI) deficiency, exhibit less than 2% of normal plasma FXI activity, display an increased bleeding tendency and are more prone to infectious diseases. FXI is one of the protein components of the contact activation system of coagulation that assembles on the surface of circulating neutrophils. Because of the central role of neutrophils in inflammation, the in vitro responses of neutrophils from normal and FXI deficient cattle were compared. Neutrophil degranulation was evaluated by measuring the release of myeloperoxidase and alkaline phosphatase, and the respiratory burst was evaluated by determining superoxide anion production. Neutrophils from FXI deficient animals exhibited a significant increase (P < 0.05) in the spontaneous release of granule contents compared to the cells from normal cattle. Following stimulation with C5a complement derived from normal serum, the neutrophils from the FXI deficient animals exhibited a greater increase (P < 0.05) in both alkaline phosphatase release and superoxide production. In these neutrophils, following stimulation with C3b complement from normal serum, the relative increase in myeloperoxidase release compared to the unstimulated neutrophils was lower than that observed in the neutrophils from normal animals. There was minimal superoxide production in unactivated neutrophils from either normal or FXI deficient cattle and the response to phorbol ester stimulation was similar in both groups of animals. The C5a complement from FXI deficient serum was more effective (P < 0.05) in stimulating alkaline phosphatase release and superoxide production in normal neutrophils than the equivalent fraction from FXI deficient serum while the C3b complement from the FXI deficient serum was less effective than the normal serum fraction at inducing myeloperoxidase release from normal neutrophils. The results indicate that the differences in the in vitro neutrophil function are likely related to a variation in the function of the contact activation system on the neutrophil surface between normal and FXI deficient animals.

Animals↗
PubMed1982

Prostatectomy in factor XI (plasma thromboplastin antecedent) deficiency.

A total of 10 patients with factor XI deficiency underwent prostatectomy: 3 who underwent suprapubic prostatectomy and 3 who underwent transurethral resection received fresh frozen plasma preoperatively, while 4 received fresh frozen plasma only in response to bleeding. We conclude that all patients who present with partial or severe factor XI deficiency should receive fresh frozen plasma preoperatively and for at least 10 to 14 days postoperatively. We believe that all Ashkenazi Jews who are about to undergo a urological operation should be screened for factor XI deficiency even when a history of a bleeding tendency is not present.

Adult↗
PubMed1998

Tissue-specific expression of functional platelet factor XI is independent of plasma factor XI expression.

Platelet factor XI is an alternatively spliced product of the factor XI gene expressed specifically within megakaryocytes and platelets as an approximately 1.9-kb mRNA transcript (compared with approximately 2.1 kb in liver cells) lacking exon V. Flow cytometry with an affinity-purified factor XI antibody, with PAC1 antibody (to the GPIIb/IIIa complex on activated platelets), and with S12 antibody (to P-selectin, an alpha-granule membrane protein expressed on the platelet surface during secretion) on platelets activated with ADP, thrombin, thrombin receptor peptide (SFLLRN amide), or collagen at various concentrations exposed platelet factor XI and PAC1 antibody binding in parallel. Unactivated platelets expressed approximately 40% of total platelet factor XI but no PAC1 binding sites. Enhanced membrane exposure of platelet factor XI is independent of alpha-granule secretion, because ADP and collagen exposed platelet factor XI but no S12 binding sites. Platelets from four patients with plasma factor XI deficiency (<0.04 U/mL) had normal constitutive and activation-dependent expression of platelet factor XI. Well-washed platelets from normal and from factor XI-deficient donors incubated with low concentrations of thrombin (0. 05 to 0.1 U/mL) corrected the clotting defect observed with factor XI-deficient plasma. Thus, functionally active platelet factor XI is differentially expressed on platelet membranes in a tissue-specific manner both constitutively and in a concentration-dependent fashion by various agonists in the absence of detectable plasma factor XI.

Adult↗
PubMed1982

Factor XI assay results in the CAP survey (1981).

Data from the 1981 CAP Survey for factor XI assay is reviewed. Different instrument reagent combinations are ranked according to precision and sensitivity. Results of the survey questionnaire are analyzed. There is poor correlation between precision and sensitivity of most systems (i.e., instrument and reagent combinations). For any given system, precision appears to decrease with increasing severity of the factor XI deficiency of the specimen. Some comparisons are made to recent CAP surveys of factor VIII and IX activity. Considerable interlaboratory variation is noted with respect to technical aspects of factor assays (i.e., dilution of normal plasma used to construct the standard curve, etc.). Procedures used by some laboratories in handling patient specimens for factor assays, such as freezing the patient specimen, may decrease the chance of identifying a mild factor XI deficiency. The need for standardization of factor assays is evident from the survey data.

Factor XI↗
PubMed2001

The role of factor XI in thrombin generation induced by low concentrations of tissue factor.

Thrombin generation has been studied in the plasma of severely factor XI deficient patients under conditions in which contact activation did not play a role. In platelet-rich as well as platelet-poor plasma, thrombin generation was dependent upon the presence of factor XI at tissue factor concentrations of between 1 and 20 pg/ml i.e. approximately 0.01 to 0.20% of the concentration normally present in the thromboplastin time determination. The requirement for factor XI is low; significant thrombin generation was seen at 1% factor XI; at 10%, thrombin formation was nearly normalised. A suspension of normal platelets in severely factor XI deficient plasma did not increase thrombin generation. This implies that there is no significant factor XI activity carried by normal platelets, although the presence of factor XI and factor XI inhibitors in platelets cannot be ruled out.

Blood Platelets↗
PubMed1990

The use of fresh blood to control severe haemorrhage associated with massive blood transfusion after cardiopulmonary bypass.

A 61-year-old man with severe factor XI deficiency presented for coronary artery bypass surgery. The clotting deficiency was corrected preoperatively with factor XI concentrate. Surgery resulted in severe postoperative haemorrhage of 55 liters of blood. This was managed successfully with a cell saver device (Haemonetics). Repeated platelet transfusions were ineffective in correcting the platelet dysfunction. The severe haemorrhage stopped suddenly after the infusion of 4 units of fresh blood. The case demonstrates how fresh blood can be useful in the management of severe haemorrhage after massive blood transfusion.

Blood Transfusion↗
PubMed2006

Arterial and venous thrombosis in rare congenital bleeding disorders: a critical review.

A thorough review of the literature and of personal files has allowed the gathering of 81 patients with rare congenital bleeding disorders and thrombotic phenomena. Sixteen of these patients had congenital afibrinogenemia, eight involved factor V deficiency, 20 factor VII defects, 33 factor XI deficiencies and only one, a factor XIII defect. Altogether 42 patients showed arterial thrombosis (myocardial infarction [MI] in 28 cases; ischemic stroke in 4; arterial occlusion in 8; 2 patients with disseminated intravascular coagulation (DIC)). Ages varied between 13 and 74. Twenty-two patients were males and 16 females. In four cases, sex was not reported. There were three fatalities: two after a MI and one because of heart failure. With regard to venous thrombosis: 9 patients had pulmonary embolism, 15 patients had deep vein thrombosis, 9 patients had both pulmonary embolism and deep vein thrombosis; 1 patient had superficial vein thrombosis, whereas, 5 cases had an unusual site venous thrombosis (two portal systems, two cerebral sinuses, one inferior vena cava) for a total of 39 cases. Age varied between 3 and 86. In this case, 20 patients were males and 17 were females. In two cases, sex was not reported. There were three fatalities: two because of pulmonary embolism and one because of inferior vena cava thrombosis. The fact that thrombosis has never been described in patients with factor II or factor X seems to underscore the central antithrombotic role that these two factors have in the coagulation system.

Adolescent↗
PubMed2005

Factor XI mutation in a Holstein cow with repeat breeding in Japan.

Factor XI deficiency is an autosomal recessive coagulopathy in Holstein cattle. Affected cows have a tendency to show repeat breeding. Forty repeat breeding Holstein Friesian cows were selected and tested for the Factor XI mutation. Genomic DNA was isolated from the blood of the cows (n=40). Exon 12 of the Factor XI gene of the cows was amplified by PCR. One repeat breeding cow was heterozygous to the Factor XI mutation as indicated by the presence of two DNA fragments of 320 bp and 244 bp. The insertion of the 76 bp in the heterozygous cow was confirmed by DNA sequencing. The heterozygous cow was in her fourth lactation. She gave birth to male twins at the last calving. She was inseminated artificially four times after the last calving. Factor XI deficiency in cattle has been reported in different countries. However, no case was reported in Japan. This might be the first to report Factor XI mutation in Holstein cattle in Japan.

Animals↗
PubMed2004

Prolonged activated partial thromboplastin time in pregnancy: a brief report.

BACKGROUND: Limited data are available regarding causes of prolonged activated partial thromboplastin time (aPTT) in otherwise normal pregnancies. We retrospectively evaluated clinical data of pregnant women in whom an elevated aPTT was noted on routine prenatal testing. Our intent was to identify various causes of prolonged aPTT and to evaluate whether the pregnancies were adversely affected. METHODS: A retrospective review of medical records of 36 pregnant patients with a prolonged aPTT as the sole abnormal coagulation test seen in the outpatient department of a tertiary care hospital over a period of 4 years. RESULTS: Patients' median age was 26 (range, 19-41) years and median duration of gestation period was 19 (range, 8-38) weeks. Fifteen patients were primigravida. Of 36 patients, repeated aPTT values were normal in 24 (67%) patients, whereas 12 (33%) patients had persistently elevated aPTT values. Factor XI deficiency was found in 5 patients, lupus anticoagulant in 3 patients, elevated anticardiolipin antibody in 2 patients, and low von Willebrand Factor level in 1 patient. Overall, 23 patients delivered. No patients experienced excessive bleeding or thromboembolism. CONCLUSION: Factor XI deficiency and antiphospholipid antibody were 2 major abnormalities identified in patients with prolonged aPTT. These coagulopathies were not associated with excessive bleeding or thromboembolism. Repeat normal aPTT in approximately 2 thirds of patients suggests that proper sample collection and processing are important for coagulation assays to avoid erroneous clotting times.

Adult↗
PubMed1994

Activation of the coagulation cascade after infusion of a factor XI concentrate in congenitally deficient patients.

Virally inactivated, high-purity factor XI concentrates are available for treatment of patients with factor XI deficiency. However, preliminary experience indicates that some preparations may be thrombogenic. We evaluated whether a highly purified concentrate produced signs of activation of the coagulation cascade in two patients with severe factor XI deficiency infused before and after surgery. Signs of heightened enzymatic activity of the common pathway of coagulation (elevated plasma levels of prothrombin fragment 1 + 2 and fibrinopeptide A) developed in the early post-infusion period, accompanied by more delayed signs of fibrin formation with secondary hyperfibrinolysis (elevated D-dimer and plasmin-antiplasmin complex). These changes occurred in both patients, but were more severe in the older patient with breast cancer when she underwent surgery, being accompanied by fibrinogen and platelet consumption. There were no concomitant signs of heightened activity of the factor VII-tissue factor mechanism on the factor Xase complex (plasma levels of activated factor VII and of factor IX and X activation peptides did not increase). The observed changes in biochemical markers of coagulation activation indicate that concentrate infusions increased thrombin generation and activity and that such changes were magnified by malignancy and surgery. Because some factor XI concentrates may be thrombogenic, they should be used with caution, especially in patients with other risk factors for thrombosis.

Adult↗