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Results for “Factor XII Deficiency”

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At least 145 records · Page 8Linked to original sources
PubMed1998

The soluble recombinant form of a binding protein/receptor for the globular domain of C1q (gC1qR) enhances blood coagulation.

The gC1qR is a ubiquitously expressed, 33 kDa cellular protein which recognizes the globular domains of C1q. Recent evidence suggests that the gC1qR also serves as the Zn(++)-dependent endothelial cell binding site for factor XII and high-molecular-weight kininogen, and activates intrinsic coagulation and kinin pathways in purified systems. In addition, activated lymphocytes have been reported to release soluble gC1qR. Thus, the present study investigated the procoagulant potential of soluble gC1qR in human plasma using the recombinant protein (rgC1qR). rgC1qR supported a dose-dependent shortening of extrinsic coagulation using the prothrombin time in the presence of diluted (1/50-1/500) thromboplastin. Maximum enhancement of the prothrombin time resulted in shortening of the clotting time from 78.8 +/- 0.4 s to 68.5 +/- 0.6 s (mean +/- SD, n = 8) in the presence of 50 micrograms/ml (1.5 mumol/l) rgC1qR. rgC1qR also enhanced the intrinsic pathway of coagulation evaluated in the absence of activators of the contact system, as demonstrated by a shortening of the plasma recalcification time from 348 +/- 66 s to 140 +/- 23 s (n = 4). rgC1qR, however, had no effect on intrinsic coagulation in the presence of undiluted kaolin or ellagic acid, and under these conditions failed to shorten the activated partial thromboplastin time of factor VIII or factor-IX-deficient plasma. rgC1qR further failed to affect thrombin and factor Xa generation assayed using chromogenic substrates, and did not enhance thrombin-induced conversion of fibrinogen to fibrin. Interestingly, the procoagulant activity of the rgC1qR was measurable in either factor-XII- or factor-XI-deficient plasma, suggesting that it was not exclusively focused on the contact system of coagulation. Although the mechanism of action of gC1qR on blood coagulation remains obscure, the data suggest a potential role for this protein in hemostatic and thrombotic events.

Blood Coagulation↗
PubMed2006

Plasma levels of bradykinin are suppressed in factor XII-deficient mice.

A genetically-transmissible factor (F) XII-inactivated allele has been produced in mice by targeted replacement of exons 3-8 of the FXII gene with the neomycin resistance gene. Interbreeding of these mice provided offspring homozygous for two inactivated FXII alleles (FXII(-/-)). Male and female FXII-deficient mice bred normally in all genotypic combinations of the heterozygous and homozygous states, and the offspring survived to adulthood, suggesting that a total FXII deficiency does not affect embryonic development and survival. Neither FXII transcripts nor FXII antigen was found in various tissues of adult FXII(-/-) mice. No obvious unchallenged coagulopathies were present in FXII(-/-) adult mice, despite greatly prolonged activated partial thromboplastin times in this mouse cohort. FXII(-/-) mice were then used to assess the in vivo importance of the plasma FXII/prekallikrein/kininogen pathway in provision of resting plasma bradykinin (BK) levels and in generation of plasma BK stimulated by contact with an artificial surface, using a new and greatly improved plasma BK assay developed during these studies. It was found that approximately 50% of resting BK, and all of the contact-stimulated plasma BK, was provided by this FXII-dependent pathway, without a requirement for FXI. These results provide clear evidence that surface-stimulated BK production, in mice, is dependent on the activation of FXII.

Animals↗
PubMed1997

Homozygous type I plasminogen deficiency.

Homozygous type I plasminogen (Plg) deficiency has not been described in human subjects so far. Ligneous conjunctivitis is a rare and unusual form of chronic pseudomembranous conjunctivitis of unknown etiology. Here we report for the first time on homozygous type I Plg deficiency in three unrelated female patients who suffered from ligneous conjunctivitis and additional pseudomembranous lesions of other mucous membranes. The disease is caused by massive fibrin depositions within the "extravascular space" of mucous membranes because of absent clearance by plasmin. Infusions of albumin, fresh frozen plasma, or Lys-plasminogen (Lys-Plg) into two of the three patients revealed normal Plg activation capacity in these patients. The absence of fibrinolytic activity could therefore be shown to be due to Plg deficiency. Similar studies in the third patient have not been completed. In the two patients studied so far, infusions of Lys-Plg resulted in prompt and adequate Plg recovery with a short half-life and high amounts of plasmin-antiplasmin complexes and D-dimer. One patient additionally revealed an inherited partial factor XII deficiency. Functionally, this factor XII deficiency did not interfere with Plg activation. However, there may be a pathway of Plg activation in this patient via the prekallikrein C1-INH system.

Adolescent↗
PubMed1977

Feline factor XII (Hageman) deficiency.

A coagulation profile from a clinically normal female cat revealed an intrinsic coagulation defect characterized by prolonged activated partial thromboplastin time, with normal bleeding time, platelet count, and prothrombin time. Subsequent correction studies, utilizing activated partial thromboplastin time, confirmed factor XII deficiency. Hematologic and clinical studies on the cat failed to reveal an underlying disease process that might result in acquired factor XII deficiency.

Animals↗
PubMed1990

Autologous bone marrow transplantation and factor XII, factor VII, and protein C deficiencies. Report of a new association and its possible relationship to endothelial cell injury.

Four patients who underwent treatment with high-dose chemotherapy (HDC) and autologous bone marrow transplantation (ABMT) and in whom posttreatment deficiencies of Factor XII and protein C subsequently developed are reported. Factor VII or Factor X deficiencies also developed in several of these patients. Three of these patients experienced chemotherapy-related cardiac, hepatic, or pulmonary toxicity. It is believed by many that endothelial cell injury may be the underlying lesion responsible for these various organ system toxicities seen in the setting of ABMT, although direct evidence of this is lacking. It is proposed that the factor deficiencies described in this report may be an additional consequence of endothelial cell injury or dysfunction. These coagulation factor deficiencies may therefore serve as both a marker to follow these organ system toxicities with and as a useful tool to better study and understand the mechanisms underlying these events. Additionally, deficiencies of either Factor VII or Factor X developed in several patients that were of a sufficient magnitude such that factor replacement therapy would be indicated before any invasive procedures or in the event of significant hemorrhage.

Adolescent↗
PubMed1984

Defective intrinsic fibrinolytic activity in a patient with severe factor XII-deficiency and myocardial infarction.

The paper reports the occurrence of myocardial infarctions in a patient with severe deficiency of blood coagulation factor XII (Hageman factor). Factor XII plays a central role in the intrinsic activation of fibrinolysis and consequently the defective intrinsic fibrinolytic activity detected in the present case casts some doubt on its role in the increased vulnerability to thrombotic accident.

Adult↗
PubMed1975

A case of Hageman factor deficiency with myeloid leukaemia.

The co-existence of blastic transformation of chronic myeloid leukaemia and an isolated deficiency of coagulation factor XII (Hageman Factor), is reported. In the absence of any evidence of factor XII deficiency in the patient's siblings and children, it is uncertain if this represents an acquired factor XII deficiency due to myeloid leukaemia, or the coincidental occurrence of myeloid leukaemia with this autosomal recessive condition.

Blood Coagulation Disorders↗
PubMed1985

Captopril-induced changes on active and inactive renin in a patient with factor XII congenital deficiency.

A linkage between prorenin, renin, and intrinsic coagulation systems has been suggested recently. We studied the behavior of renin, prorenin, and kallikrein in a patient affected by congenital factor XII deficiency. Captopril test, upright posture, and furosemide administration provoked in our patients changes of renin and prorenin similar to those found in normal and hypertensive subjects. Unchanged kallikrein levels confirmed that no interaction between prorenin activation and factor XII-kallikrein system appears to be present.

Adult↗
PubMed1993

Factor XII (Hageman) deficiency in women with habitual abortion: new subpopulation of recurrent aborters?

OBJECTIVE: To examine the possible association between factor XII (FXII) deficiency and an elevated number of abortions. DESIGN: Factor XII activity, FXII antigen concentration, other blood clotting parameters, and phospholipid antibodies were examined in venous blood from 43 women with repeated (3 to 7) abortions before the 28th week of gestation but without gynecological and chromosomal abnormalities. The data were compared with those obtained from 49 age-matched women without fetal loss. RESULTS: Eight cases with moderately reduced FXII activity (35% to 68% of normal) could be identified in the abortion group, whereas among controls no abnormalities in FXII activity and antigen concentration were found. The relative occurrence of reduced FXII level was higher among patients with more than three abortions as compared with those with three abortions. CONCLUSION: Repeated abortions may be associated with reduced level of FXII activity of unknown origin.

Abortion, Habitual↗
PubMed1986

[Successes and failures of the activated partial thromboplastin time in the preoperative evaluation].

In a prospective study assessing haemostatic functions, the activated partial thromboplastin time was prolonged in 134 out of 10,229 patients studied, without an increase in the prothrombin or thrombin times; this abnormality persisted in only 37 of them on a new blood sample. A retrospective analysis was made of 265 patients who had such an isolated prolongation of the activated partial thromboplastin time on two successive blood samples: the causal abnormality remained unexplained in 135 patients; a well defined coagulation disorder without abnormal bleeding tendency was present in 110 patients (1 severe factor XII deficiency, 58 partial factor XI or XII deficiencies and 51 lupus anticoagulants); a bleeding disorder was diagnosed in 20 patients (8 haemophilias, 8 Von Willebrand's diseases, 4 factor VIII inhibitors). The well-iron efficacy of the activated partial thromboplastin time for detecting coagulation abnormalities is counter-balanced by some disadvantages such as the delay for biologic conclusions. In the preoperative assessment of haemostatic functions, rather than taking a routine approach, it would seem better to determine for each patient the need and the extent of biological testing according to the type of planned surgery, the clinical status of the patient and possible bleeding symptoms.

Blood Coagulation Tests↗
PubMed1992

Hageman factor deficiency presentation and implications for management.

One of the more fascinating aspects of patient management arises when dealing with coagulation disorders. Factor XII deficiency, first described by Ratnoff in 1968, is one such coagulation disorder which provides some interesting challenges in management. Factor XII deficiency has been shown to be an inherited autosomal recessive disorder. The presence of Hageman factor abnormality trait can be clinically suspected in a patient with a prolonged activated partial thromboplastin time (APTT), normal prothrombin time (PT), normal bleeding time, and no clinical history of bleeding. Once suspected, the deficiency can be confirmed by normalization of partial thromboplastin time (PTT) with normal aged plasma and by factor assay. The importance of understanding the mechanism of factor XII deficiency has clinical significance when attempts are made to heparinize individuals who have this deficiency. Three methods can be used to monitor therapy: the chromogenic heparin assay, the citrated thrombin time, and the recalcified thrombin time. Two cases are presented.

Aged↗
PubMed1979

Factor-XII congenital deficiency. A new family study.

This report describes two people in a family with Hageman trait (homozygotes) (Factor XII = 0.06%). In addition eight family members were studied to evaluate the inheritance of this congenital deficiency. A study of the Kallikrein-Kininogen system induced by the fragments of Factor XII was carried out. It is concluded that the inheritance is as described by Veltkamp and that the Kallikrein release from the prekallikreinogen (Fletcher factor) "in vitro" is related to the amount of Factor XII procoagulant protein.

Adult↗