Fitzgerald factor (high molecular weight kininogen) clotting activity in human plasma in health and disease in various animal plasmas.

Fitzgerald factor (high molecular weight kininogen) is an agent in normal human plasma that corrects the impaired in vitro surface-mediated plasma reactions of blood coagulation, fibrinolysis, and kinin generation observed in Fitzgerald trait plasma. To assess the possible pathophysiologic role of Fitzgerald factor, its titer was measured by a functional clot-promoting assay. Mean +/- SD in 42 normal adults was 0.99+/-0.25 units/ml, one unit being the activity in 1 ml of normal pooled plasma. No difference in titer was noted between normal men and women, during pregnancy, or after physical exercise. Fitzgerald factor activity was significantly reduced in the plasmas of eight patients with advanced hepatic cirrhosis (0.40+/-0.09 units/ml) and of ten patients with disseminated intravascular coagulation (0.60+/-0.30 units/ml), but was normal in plasmas of patients with other congenital clotting factor deficiencies, nephrotic syndrome, rheumatoid arthritis, systemic lupus erythematosus, or sarcoidosis, or under treatment with warfarin. The plasmas of 21 mammalian species tested appeared to contain Fitzgerald factor activity, but those of two avian, two repitilian, and one amphibian species did not correct the coagulant defect in Fitzgerald trait plasmas.     

The Relation of 'Fletcher Factor' to Factors XI and XII

S ummary . Further evidence is presented for the existence of a new coagulation factor which is closely related to Hageman factor (XII) and plasma thromboplastin antecedent, PTA (XI). This factor has been tentatively designated 'Fletcher factor'. Coagulant activity of Fletcher factor was separated from the clotting activity of factors XI and XII by C-M Sephadex column chromatography of intact normal plasma. Other studies showed that the prolonged partial thromboplastin time or plasma recalcification time of Fletcher-deficient plasma could be 'corrected' by prolonged contact with celite, glass, kaolin, or ellagic acid; all are known activators of factor XII. Cytochrome c, known to inhibit the contact activation of factor XII, completely abolished this contact 'correction' of Fletcher-deficient plasma. Thus, the clotting times of plasmas deficient in Fletcher factor (presently found in seven individuals from four unrelated families) are readily corrected by activated factors XII and XI. None of these individuals has any bleeding tendencies.
Fletcher factor activity is deficient in the plasma of newborn infants; the factor is probably produced in the liver and not dependent on vitamin K for its synthesis.     

Role of surface in surface-dependent activation of Hageman factor (blood coagulation Factor XII)

The mechanism by which negatively charged substances such as celite, kaolin, or ellagic acid contribute to the surface-dependent activation of Hageman factor (Factor XII) was studied. Kinetic studies of the proteolytic activation of (125)I-labeled human Hageman factor by human plasma kallikrein, plasma, activated Factor XI, and trypsin were performed in the presence and absence of high molecular weight kininogen and surface materials such as celite, kaolin, or ellagic acid. The results showed that surface-bound Hageman factor was 500 times more susceptible than soluble Hageman factor to proteolytic activation by kallikrein in the presence of high molecular weight kininogen. Surface binding of Hageman factor enhanced its cleavage by plasmin, activated Factor XI, and trypsin by 100-fold, 30-fold, and 5-fold, respectively. On a molar basis, trypsin was twice as potent as kallikrein in the cleavage of the surface-bound Hageman factor, while plasmin and activated Factor XI were an order of magnitude less potent than kallikrein. Kallikrein even at concentrations as low as 0.5 nM (i.e., 1/1000th of the concentration of prekallikrein in plasma) was very potent in the limited proteolysis of the surface-bound Hageman factor. These results suggest that substances classically known as "activating surfaces" promote the activation of Hageman factor indirectly by altering its structure such that it is much more susceptible to proteolytic activation by other plasma or cellular proteases.     

A new case of high-molecular-weight kininogen inherited deficiency

A preoperative hemostasis study discovered a prolonged activated partial thromboplastin time in a 23-year-old Portuguese Caucasian woman without personal or past family history of hemorrhage or thrombosis. This was corrected by pooled plasma that excluded circulating anticoagulant. Activated partial thromboplastin time was prolonged whatever the activator, particularly ellagic acid, and was not corrected by prolonged kaolin incubation. Levels of factors VIII and XII were normal; factor XI and prekallikrein levels were either moderately low or normal according to activators and defective reagents used. High-molecular-weight kininogen (HMWK) level assessed by coagulation and immunological method was virtually nil. Fibrinolysis activity was normal before and after venous occlusion. The programmed operation was performed without any particular preparation and no complication arose. Family investigation found heterozygous HMWK deficiency in the proposita's father and three of her siblings.     

A hitherto undescribed plasma factor acting at the contact phase of blood coagulation (Flaujeac factor): case report and coagulation studies.

This paper reports an asymptomatic coagulation defect responsible for an abnormality at the contact phase of blood coagulation in vitro, distinct from Hageman factor and Fletcher factor deficiencies. Coagulation studies in a 50-yr-old French woman without bleeding tendency revealed the following results: whole-blood clotting time in glass tubes and activated partial thromboplastin time with kaolin and ellagic acid were greatly prolonged; one-stage prothrombin was normal; no circulating anticoagulant was detected, and the infusion of normal plasma corrected the coagulation defect with an estimated half-life of 6.5 days; the levels of factor VIII, IX, XI, and XII were normal; mutual correction was obtained with a Fletcher factor-deficient plasma; the level of whole complement was normal. Studies of the contact phase of blood coagulation and contact-induced fibrinolysis showed the same abnormalities as in Hageman factor- and Fletcher-deficient plasmas. These results indicate that the patient's plasma is deficient in a previously undescribed coagulation factor, which participates in the initial stage of the blood coagulation process in vitro. Family studies revealed consanguinity in the propositus' parents. The assay of this newly described factor in the propositus' children revealed a partial defect, compatible with a heterozygous state, in three of the four tested children. This indicates a recessive inheritance of this new blood coagulation defect.     

Fletcher Factor Deficiency: Family Study and Detection

Eight of 11 children of a known Fletcherfactor-deficient individual were found tohave normal activated partial thromboplastin times, normal levels of factors VIII,IX, XI, and XII, and a mean Fletcher factorlevel of 53% (range 40%-72%), suggesting a heterozygous state for the genecontrolling Fletcher factor production. Allpartial thromboplastin time reagents containing celite or kaolin were sensitive toFletcher factor deficiency, while one reagent containing ellagic acid did not detect this abnormality. The finding of anabnormal partial thromboplastin time thatis corrected by a 10-min incubation periodis presumptive evidence for Fletcher factordeficiency.

Submitted on July 13, 1973 Revised on October 28, 1973 Accepted on November 5, 1973     

Connective tissue activation. XXVIII. A connective tissue activating peptide from human urine

A protein factor in human urine which has the ability to activate connective tissue cells has been identified and partially purified; it appears to be different from epidermal growth factor and IgG. This urinary connective tissue activating factor (CTAP-U) is nondialyzable, labile to protease, stable to thiols, heat, and acid, and has an acidic isoelectric point. Purified preparations of CTAP-U have biologic activities that cause human connective tissue cells to synthesize incremental amounts of 14C-hyaluronic acid, 35S-proteoglycans, and 3H-DNA in vitro. The cell spectrum responsive to this substance includes human synovial cells, human chondrocytes, and skin fibroblasts. CTAP-U does not react with antisera to connective tissue activating peptide-III or to antibodies against IgG or its Fc and Fab fragments. Furthermore, CTAP-U does not cross-react in a radioreceptor assay for insulin, basic somatomedin, or epidermal growth factor-urogastrone. Utilizing standardized isolation conditions, CTAP-U preparations with these properties have been isolated from the urine of 6 normal individuals.     

Interactions among Hageman factor, plasma prekallikrein, high molecular weight kininogen, and plasma thromboplastin antecedent.

To investigate the earliest steps of the intrinsic clotting pathway, Hageman factor (Factor XII) was exposed to Sephadex gels to which ellagic acid had been adsorbed; Hageman factor was then separated from the gels and studied in the fluid phase. Sephadex-ellagic acid-exposed Hageman factor, whether purified or in plasma, activated plasma thromboplastin antecedent, but only when high molecular weight kininogen was presnet. In the absence of plasma prekallikrein, maximal activation of plasma thromboplastin antecedent was slightly delayed in plasma, a delay not observed with similarly treated purified Hageman factor. Thus, high molecular weight kininogen was needed for expression of Hageman factor's clot-promoting properties and plasma prekallikrein played a minor role in the interaction of ellagic acid-treated Hageman factor and plasma thromboplastin antecedent.     

Demonstration of a platelet bypass mechanism in the clotting system using an acquired anticoagulant

A lupus-type anticoagulant which causes strong inhibition of the partial thromboplastin time with kaolin (PTTK), the stypven time, and the thrombin generation tests has been investigated. All tests for platelet function were normal, as were all specific coagulation factor assays with the exception of a slightly reduced factor XI in this patient. A diethylaminoethyl-cellulose-immunoglobulin (DEAE-cellulose-IgG) fractionation of the patient's plasma produced two peaks containing inhibitory activity in the PTTK test. The first of these peaks had a cloudy appearance, suggesting the presence of immunoglobulin aggregates. Studies with IgG aggregates prepared from normal IgG and from the patient's IgG demonstrated that such aggregates were not the cause of inhibition. It was possible to neutralize the inhibitory activity of the purified IgG but not platelet-poor plasma (PPP) with a rabbit anti-IgG. The inhibition of the patient's PPP in the thrombin generation, the contact product, and the stypven time tests were corrected by the inclusion in the test system of platelets activated either by aggregation due to adenosine diphosphate (ADP) or formalin fixation and washing. These studies lend support to earlier findings that platelets interact at several sites in the coagulation cascade.     

Severe fletcher factor (plasma prekallikrein) deficiency with partial deficiency of hageman factor (factor xii): Report of a case with observation on in vivo and in vitro leukocyte chemotaxis

A case of cross-reacting material-negative Fletcher trait with additional partial deficiency of Hageman factor (HF, Factor XII) is described. Although the patient presented with a recent history of frequent epistaxis, he had no other personal or family history of a tendency toward bleeding or infection. Similar to other cases of Fletcher trait, his plasma showed a markedly prolonged partial thromboplastin time which could be corrected by prolonged incubation with the surface-activator kaolin. Surface-induced fibrinolysis, amidolysis of α-N-benzoyl-proline-L -phenylalanine-L -arginine-p-nitro- anilide, and cold-promoted enhancement of factor VII activity, reactions requiring the presence in the plasma of Fletcher factor (pre-kallikrein), in addition to Hageman factor and Fitzgerald factor (high-molecular weight kininogen), were also defective. In vivo chemotaxis of polymorphonuclear leukocytes and monocytes (Rebuck's skin window technique) in response to skin abrasions was defective, but was normal when diphtheria-tetanus toxoid was also applied. In vitro leukocyte chemotaxis (Boyden chamber technique) in response to normal or patient's own serum activated with zymosan was normal. Together with previous observations that kallikrein generated chemotactic activity, possibly via activation of C5, the present observations suggest that prekallikrein activation may be important for in vivo leukocyte chemotactic response to skin abrasion. The inheritance of Fletcher trait in this patient is unclear. Although the father was an apparent heterozygote, the mother was completely normal for Fletcher factor procoagulant activity and antigen. The mild Hageman factor deficiency in the patient did not contribute significantly to the plasma defects described and was likely inherited from the father who had a low HF procoagulant activity.     

Connective tissue activation

A protein factor in human urine which has the ability to activate connective tissue cells has been identified and partially purified; it appears to be different from epidermal growth factor and IgG. This urinary connective tissue activating factor (CTAP-U) is nondialyzable, labile to protease, stable to thiols, heat, and acid, and has an acidic isoelectric point. Purified preparations of CTAP-U have biologic activities that cause human connective tissue cells to synthesize incremental amounts of ¹⁴C-hyaluronic acid, ³⁵S-proteoglycans, and ³H-DNA in vitro. The cell spectrum responsive to this substance includes human synovial cells, human chondrocytes, and skin fibroblasts. CTAP-U does not react with antisera to connective tissue activating peptide-III or to antibodies against IgG or its Fc and Fab fragments. Furthermore, CTAP-U does not cross-react in a radioreceptor assay for insulin, basic somatomedin, or epidermal growth factor-urogastrone. Utilizing standardized isolation conditions, CTAP-U preparations with these properties have been isolated from the urine of 6 normal individuals.     

Some characteristics of aggregates of IgG and plasma proteins in heat-treated factor VIII concentrates

Summary Eight batches of commercial heattreated and one untreated factor VIII concentrate from 6 producers were analyzed for their content of IgG, IgG subclasses, IgG aggregates and the presence of other plasma proteins combined with the IgG as well as for anticomplement activity. Methods used were thin-layer gel filtration, immuno-gel filtration, spot immuno-precipitate assay in a double antibody version and an agarose plate haemolysis inhibition assay of complement fixation. The IgG content varied from 0.1–6.90 g/l. In all preparations IgG existed as monomers and aggregates. Associated with the IgG were also found, at significantly increased amounts compared to normal serum and intravenous immunoglobulin, one to four of the following plasma proteins; fibronectin, fibrinogen, von Willebrand factor antigen, Clq, albumin and IgA. Three batches from two producers had high anticomplementary activity, presumably caused by the IgG aggregates. Two of these deviated strikingly from normal human serum pools in percent distribution of IgG subclasses. It is hypothesized that these aggregates can induce side effects or cause immunological aberrations.     

A unique precipitating autoantibody against plasma thromboplastin antecedent associated with multiple apparent plasma clotting factor deficiencies in a patient with systemic lupus erythematosus

A 42-yr-old woman with systemic lupus erythematosus without bleeding diathesis developed a prolonged activated partial thromboplastin time that was not corrected by normal plasma. An inhibitor that acted rapidly and inactivated 0.5 U/ml plasma thromboplastin antecedent (PTA, factor XI) at a 1:200 plasma dilution was demonstrated. In addition to a low titer of PTA (less than 0.01 U/ml), plasma assayed at 20-fold dilution also showed low titers of Hageman (factor XII, 0.02 U/ml), Fletcher (plasma prekallikrein, 0.02 U/ml), and Fitzgerald (high molecular weight kininogen, less than 0.01 U/ml) factors. The titer of these factors, except PTA, returned to normal upon further plasma dilution or upon removal of the inhibitor by protein A adsorption. Thus, the inhibitor appeared to interfere with these clotting factor assays, possibly by inactivating PTA in the substrate plasmas in the test system. Its specificity was further confirmed. The inhibitor did not interfere with surface-induced proteolytic cleavage of Hageman factor. Surface-induced generation of plasma kallikrein activity (amidolysis of H-D-pro-phe-arg-pNa and cold-promoted factor VII activity enhancement) requires only Hageman, Fletcher, and Fitzgerald factors and was normal. Reactions requiring all 4 contact phase factors, including PTA, such as surface-induced generation of plasmin activity (amidolysis of H-D-val-leu-lys-pNa) and activated Christmas factor (factor IXa) activity, were defective. Furthermore, the inhibitor bound to agarose-protein A inactivated and removed PTA selectively from normal plasma. The inhibitor was an IgG-lambda autoantibody that precipitated PTA. The inactivated activated PTA (factor XIa) without the requirement for an additional cofactor. Furthermore, it inhibited surface-induced activation of PTA by interfering with its proteolytic cleavage upon glass surface exposure and with its binding onto the reactive surfaces.     

Functional and binding studies of the roles of prothrombin and beta 2- glycoprotein I in the expression of lupus anticoagulant activity

We present functional and binding data relevant to the reported roles for prothrombin and beta 2-glycoprotein I (beta 2GPI) in the expression of lupus anticoagulant activity. In a purified system containing human prothrombin, Xa, Va, and a rate-limiting concentration of phosphatidylserine (PS)/phosphatidylcholine (PC) vesicles, the preliminary incubation of vesicles with protein A separated IgG preparations from 10 lupus anticoagulant plasmas, calcium, and prothrombin enhanced the inhibitory effect of all IgG preparations upon thrombin generation. Experiments in a purified factor X activation system provided supporting data that a similar preliminary incubation with prothrombin enhanced the inhibitory effect of many of the IgG preparations upon factor X activation. However, we could not obtain unequivocal evidence that prothrombin was an obligatory cofactor for lupus anticoagulant IgG to inhibit procoagulant phospholipid function, because lupus anticoagulant IgG separated by protein A chromatography contained traces of prothrombin. The binding of many IgG preparations to immobilized PS was enhanced by prothrombin when calcium ions were present. beta 2GPI enhanced binding of many of the IgG preparations to immobilized PS both in the presence and absence of calcium, yet beta 2GPI failed to enhance the ability of the IgG preparations to inhibit phospholipid function in purified prothrombin and factor X assays. Moreover, the IgG preparations prolonged the dilute Russell's viper venom time (dRVVT) of beta 2GPI-depleted normal plasma. Nine of 10 IgG preparations bound to prothrombin on Western blots in the absence of calcium and phospholipid, whereas no preparation bound to beta 2GPI. Passage of five citrated lupus anticoagulant plasmas through a prothrombin affinity column in the absence of added calcium and phospholipid removed most of the activity prolonging the dRVVT of normal plasma, and IgG in the pass-through plasma no longer bound to PS in the presence of prothrombin and calcium ions. IgG in prothrombin column eluates had strikingly enhanced specific lupus anticoagulant activity and also specific PS binding activity in the presence of prothrombin and calcium ions. Thus, lupus anticoagulant plasmas were shown to contain IgG binding to prothrombin, in the absence of calcium ions and phospholipid, which could also, in the presence of calcium ions and prothrombin, bind to PS and express lupus anticoagulant activity.     

Characterization of molecular defects of Fitzgerald trait and another novel high-molecular-weight kininogen-deficient patient: insights into structural requirements for kininogen expression

A 6-year-old male with vertebral-basilar artery thrombosis was recognized to have high-molecular-weight kininogen (HK) deficiency. The propositus had no HK procoagulant activity and antigen (< 1%). Using monoclonal antibodies (Mabs) to kininogen domain 3, the propositus, family members, and Fitzgerald plasma were determined to have detectable low-molecular-weight kininogen. Mabs to HK domains 5 and 6 do not detect HK antigen in the propositus' plasma. The propositus has a single base pair (bp) deletion in cDNA position 1492 of exon 10 affecting amino acid 480 of the mature protein and resulting in a frameshift and a premature stop codon at position 1597 (amino acid 532). Unexpectedly, Mabs to the heavy chain and domain 5 of HK detect a 92-kDa form of HK in Fitzgerald plasma, the first HK-deficient plasma. The 92-kDa Fitzgerald HK has amino acid residues through 502, corresponding to domains 1 through 5, but lacks epitopes of domain 6 (positions 543 to 595). Fitzgerald DNA has a normal exon 10, but a 17-bp mutation in intron 9. These combined results indicate that mutations in the kininogen gene may differentially affect biosynthesis, processing, and/or secretion of HK.     

In vivo recovery with products of very high purity — assay discrepancies

Summary. In view of reports of FVIII assay discrepancies in post-infusion plasma samples depending on methods used, we compared FVIII results run by each of four different methods following infusion of rFVIII (Kogenate®). Nine persons with haemophilia A were infused with each of two lots of product. Plasma samples were obtained at baseline, and at 10 min, 30 min, 1, 2, 4, 8, 12, 14, 30 and 48 h post-infusion for measurement of FVIII. FVIII assay methods were chromogenic, and one-stage APTT using three different types of activators: micronized, silica, ellagic acid, and kaolin. The same reference plasma standard was used throughout. Results demonstrated a consistent difference in FVIII values, with chromogenic assays being considerably higher than those run by one-stage assays. The discrepancy was greatest when kaolin was the activator. These results point out the problems in attempting to determine the “correct” FVIII level in patient plasma samples following infusion of high purity FVIII preparations. Potential “pitfalls” include the standard used for defining product potency, the methods, reagents, instrumentation and standards used in assaying plasma samples and, in some instances, the characteristics of the product itself. This situation has considerable cost implications, potential impact on patient care, and makes it difficult to compare results between laboratories.     

Platelet satellitosis to polymorphonuclears: cytochemical, immunological, and ultrastructural characterization of eight cases

Satellitosis of platelets to polymorphonuclears was observed in eight patients. This phenomenon occurred only in blood anticoagulated by EDTA at room temperature. In vivo and in vitro platelet and neutrophil function were normal. Electron microscopy studies showed normal structures in both cells but demonstrated platelet phagocytosis by neutrophils. In all cases we were able to transfer the platelet satellitosis factor by mixing platelet plasma (or serum) with whole blood from ABO compatible healthy controls; conversely, when the same plasma (or serum) was pre-incubated with anti-IgG serum, satellitosis to normal blood was not observed. While this finding suggests that a plasmatic protein with the properties of an IgG immunoglobulin was probably responsible for the phenomenon, we were unable to correlate it with the clinical condition of the patient, functional abnormalities of the blood components, or drugs.     

Properties of sulfatides in factor-XII-dependent contact activation

Incubation of normal human plasma with low amounts of sulfatides resulted in the initiation of intrinsic coagulation and the appearance of kallikrein activity. The optimal initiation of procoagulant and kallikrein amidolytic activity was dependent on the presence of factor XII, high molecular weight kininogen, and prekallikrein. Since the activated partial thromboplastin clotting times in prekallikrein- deficient plasma approach normal values upon prolonged incubation with kaolin, this phenomenon of autocorrection was studied and found to be even more pronounced in the presence of sulfatides. Autocorrection was essentially completed in 5 min in the presence of sulfatides, whereas a preincubation of 15-20 min was required in the presence of kaolin. The limited proteolysis of 125I-factor XII in plasma during incubation with activating material or during clotting was determined. Cleavage of factor XII was more rapid and more extensive in the presence of sulfatides than in the presence of kaolin. In prekallikrein-deficient plasma, factor XII cleavage was completed within 5 min in the presence of sulfatides and within 15 min in the presence of kaolin. Thus, the appearance of factor-XII-dependent coagulant activity correlates with the limited proteolysis of factor XII when normal or prekallikrein- deficient plasma is activated by sulfatides or kaolin.