An ultrapure plasma-derived monoclonal antibody-purified factor IX concentrate (Nonafact®), results of phase III and IV clinical studies.

Nonafact(®), an ultrapure, monoclonal antibody-purified factor IX concentrate (FIX) was developed to minimize risk of thrombotic complications and viral transmission. To investigate the pharmacokinetics, efficacy and safety, phase III/IV studies were performed in the Netherlands and Poland from 1996 to 2007. The mean half-life, in vivo response and recovery of Nonafact(®) were 18.7 (SD 2.0) h, 1.1 (SD 0.2) IU dL(-1) per IU kg(-1) b.w. of FIX infused and 49% (SD 10%), respectively. Eleven surgical procedures were performed in eight patients. During two surgeries, both high-risk, blood loss was observed. No postoperative bleeding occurred. The in vivo recovery of FIX was higher than expected. In the phase III follow-up study, 26 previously treated patients (PTP) were included with a median follow-up of 1130 days. From the 1617 minor bleedings, 80.5% was stopped after a single infusion. In the phase IV study thirteen patients were treated for a median study period of 737 days. In the two follow-up studies the investigators rated the effect of Nonafact(®) as excellent/good in 95% of major bleedings. Surgeries for which Nonafact(®) was given prophylactically were without bleeding problems. In total more than 10 million units of Nonafact(®) were used during almost 120 person-years. Only one minor adverse event was reported. No inhibitors, viral transmissions and thrombogenic events occurred. In conclusion, Nonafact(®) is safe and provides excellent haemostasis in haemophilia B patients treated for spontaneous bleeding or undergoing surgical procedures. Due to the excellent in vivo recovery characteristic, treatment with Nonafact(®) is cost saving compared to other FIX products.

Difference between type I autoimmune inhibitors of fibrin stabilization in two patients with severe hemorrhagic disorder.

Inhibitors of fibrin stabilization of apparently autoimmune origin, found in two severely bleeding unrelated patients (W. G. and G. A.), were compared with regard to their biological target specificities, potencies and immunological characteristics. Both interfered only with the activation of fibrin stabilizing factor (coagulation Factor XIII) and, while totally preventing the conversion of this zymogen to the functional transamidating enzyme, fibrinoligase (Factor XIII(a)), they showed very little inhibition toward the enzyme itself. Thus, according to the classification of Lorand concerning biological specificities, both can be characterized as Type I inhibitors of fibrin stabilization. Potencies of the two inhibitors were quite similar when measured in conjunction with the plasma zymogen, but they differed remarkably in tests with platelet Factor 13. The inhibitor of patient W. G. prevented the activation of the zymogen from platelets, but that of G. A. had no effect on the platelet factor. It may therefore be concluded that the inhibitor of W. G. is directed exclusively against the a subunit which is a common constituent of plasma as well as platelet factors. The inhibitor of G. A., however, must be targeted against determinants uniquely characteristic for the ab ensemble of the plasma zymogen including the b subunit. On the basis of this difference in target specificity, the inhibitor of W. G. is designated as Type I-1 and that of G. A. as Type I-2. The inhibitors of both patients were isolated as immunoglobulins, and neutralization tests revealed that the antibody of W. G. comprised mainly heavy chains of the IgG1 and light chains of the kappa class. The antibody of G. A. proved to be considerably more heterogeneous and contained IgG1 and IgG3 heavy chains as well as kappa- and lambda-light chains. The finding that the antibody of W. G. inhibited conversion of platelet Factor 13 and also its thrombinmodified form, but had no effect on the thrombin and Ca(2+)-activated factor, is an indication that antigenic determinants existing both on the native zymogen and on its hydrolytically modified form become buried in the Ca(2+)-dependent step of activation. This is clear evidence for the occurrence of a significant conformational change in the protein structure attendant to the process of unmasking of its enzymic activity.

Effect of proteolysis on quantitation of plasma fibronectin concentration by two immunoassays (electroimmunoassay and immunoturbidimetric technique).

Quantitation of fibronectin (FN) concentration is strongly influenced by FN fragmentation with trypsin, kallikrein and plasmin. Digestion by trypsin and kallikrein leads to a progressive decline in FN detectability by the immunoturbidimetric technique to zero values but is associated with an increase in the height of rockets in the Laurell's electroimmunoassay. Plasmin mediated FN fragmentation induces a strong overestimation of the FN content by the electroimmunoassay and, at very high enzyme concentrations, provokes an underestimation of FN by the immunoturbidimetric technique. The decline in FN reactivity in the immunoturbidimetric assay coincides with the disappearance of heavy fractions migrating only slightly faster than native FN in SDS-PAGE. The increase in the height of rockets in the electroimmunoassay is the highest when fractions of intermediate rate of migration prevail in the SDS-PAGE pattern. Concomitant use of these two immunoassays can distinguish native FN from its degraded form and may possibly provide a partial explanation for discrepancies in published studies on the concentration of circulating FN in various pathological states.

Anticoagulant properties of extracellular slime substance produced by Staphylococcus epidermidis.

Slime produced by S. epidermidis strain KH 11 was extracted with phenol-saline. The saline phase was fractionated on a DEAE-Sepharose CL-6B column. The crude slime solution and its phenol-saline fraction were found to possess anticoagulant properties. They inhibited the coagulation of human plasma by thrombin, prolonged the activated partial thromboplastin time, but did not change the rate of plasma coagulation by reptilase. The anticoagulant effect of slime could be neutralized by rather high concentrations of protamine sulphate. In the presence of plasma, the staphylococcal slime also inhibited in a concentration dependent fashion the amidolytic activity of thrombin and factor Xa against synthetic chromogenic substrates. Both antithrombin III (AT III) and other plasma component(s), presumably heparin cofactor II, were required for the full expression of the slime effect. The anticoagulant action of slime was markedly less AT III dependent than that of heparin. The activity was resistant to heating (100 degrees C, 30 min). Slime and its fractions were stronger inhibitors of thrombin than of factor Xa. Fraction IV separated by DEAE-Sepharose chromatography and particularly rich in galactose and glucuronic acid had the highest inhibitory potency. It is conceivable that slime component(s) similar to glycosaminoglycans from other sources can carry the anticoagulant activity.

Venostasis but not DDAVP infusion provokes the plasma fibronectin increase.

Plasma fibronectin (pFN), von Willebrand factor antigen (vWf:Ag), factor VIII procoagulant activity, fibrinogen, euglobulin lysis time (ELT) and hematocrit were determined in healthy blood donors before and after venostasis as well as after intravenous infusion of 1-deamino-8-D-arginine vasopressin (DDAVP). Both venostasis and DDAVP provoked an increase in vWf:Ag and shortening in the ELT. In contrast, venostasis only but not DDAVP induced an increase in pFN levels which was statistically significant with and without correction for a concomitant hematocrit increment. The results indicate that there is a distinct difference in the patterns of venostasis and DDAVP mediated release of proteins from the vessel wall.

Different effects of human neutrophil elastase on platelet glycoproteins IIb and IIIa of resting and stimulated platelets.

The effect of human neutrophil elastase (HNE) on the structure and receptor activity of platelet glycoprotein IIb/IIIa complex was studied. Resting platelets, which bound only traces of 125I-fibrinogen in the absence of ADP, were found to be barely susceptible to HNE. As shown by immunoblotting experiments, treatment of such platelets with HNE (14 micrograms/ml) did not provoke a detectable cleavage of GPIIb but resulted in a partial digestion of GPIIIa and appearance of 110 kDa fragment. Such proteolytic modification of the GPIIb/IIIa complex was accompanied by a slight increase in the binding of fibrinogen to blood platelets in the absence of ADP. Treatment of partially activated platelets (spontaneous activation during washing procedure) with HNE caused a progressive loss of GPIIb and degradation of GPIIIa to 110 kDa and 60 kDa fragments. These spontaneously stimulated platelets had initially a high number of fibrinogen binding sites exposed, corresponding to approximately 50% of receptor capacity observed in platelets activated by the optimal concentration of ADP. Digestion of GPIIb/IIIa by HNE of such platelets markedly increased the exposure of fibrinogen receptors. Thus, the stimulation of platelets increases significantly the susceptibility of the GPIIb/IIIa complex to proteolysis by HNE. However, such modification of the GPIIb/IIIa does not destroy its function as a receptor for fibrinogen either on the resting or activated platelets.

Monocytes of patients congenitally deficient in plasma factor XIII lack factor XIII subunit a antigen and transglutaminase activity.

Monocytes isolated from patients with severe deficiency in plasma Factor XIII of blood coagulation (FXIII) were tested for FXIII antigen and transglutaminase activity. By immunoperoxidase method the patients' monocytes, in contrast to normal controls, showed no reaction with a monospecific antibody against FXIII subunit a. This result was confirmed by immunoblotting technique, as well. In addition, tissue macrophages tested in one of the patients were also exempt of FXIII subunit a antigen. The transglutaminase activity in FXIII deficient monocytes was below the limit of the detection of the dansylcadaverine incorporation assay. The results suggest that FXIII subunit a of monocytes/macrophages and its plasma and platelet counterparts are closely related or identical proteins and demonstrate that the transglutaminase activity in monocytes is of FXIII origin and tissue transglutaminase is present, if at all, only in insignificant amount.

Effects of neutral proteases from human leukocytes on structure and biological properties of human factor VIII.

Human factor VIII was purified from cryoprecipitate and incubated for up to 24 hours with four neutral proteases of human blood leukocytes, namely, with elastase-like protease (ELP), chymotrypsin-like protease (CLP), collagenase and gelatinase. Electrophoretic patterns showed a reproducible sequence of degradation of factor VIII and of its 230,000 molecular weight subunit by ELP and CLP. Intermediate products were similar but those resulting from exhaustive proteolysis by ELP and CLP differed distinctly from each other. Procoagulant activity of factor VIII was rapidly and completely destroyed by ELP and CLP before visible electrophoretic changes would be detected. No increase in this activity was observed prior to its destruction. Von Willebrand factor (ristocetin cofactor) activity was considerably more resistant to ELP and CLP and declined in rough relation to degradation of highly aggregated forms of factor VIII. ELP and CLP produced a pronounced progressive increase in the Laurell reaction antigen. Normal human plasma showed a high potency to inhibit ELP and CLP. Large doses of these enzymes (300 microgram per ml) produced in the plasma medium only a moderate fall in factor VIII procoagulant activity. Collagenase and gelatinase did neither degrade factor VIII nor change its biological properties.

HIV antibody status and immunological abnormalities in Polish haemophiliacs.

Sera of 520 multitransfused haemophiliacs were examined for antibody to HIV; 447 patients had haemophilia A and 73 had haemophilia B. In 382 patients with haemophilia A and in 62 with haemophilia B solely Polish-made blood products were used for replacement therapy. The remaining haemophiliacs had also received imported clotting factor concentrates prior to the investigation. Only 8 patients (haemophilia A - 7, haemophilia B - 1) developed anti-HIV and all of them had been exposed to commercial concentrates. The analysis of T-cell subsets demonstrated an inverted T4/T8 ratio (less than 1.0) in 7 (30%) of the 23 haemophiliacs treated solely with domestic cryoprecipitate and in 3 (37%) of the 8 seropositive recipients of commercial concentrates. The most frequent alteration in both subgroups was a reduced ratio with either normal absolute numbers or an increase in T8 cells. Increased serum IgG levels were found in 82% of the users of cryoprecipitate and in 75% of the seropositive patients. Serum beta-2-microglobulin level was elevated in 69 and 62% of each subgroup, respectively. The observed immunological abnormalities, at least in the cryoprecipitate treated subgroup, may be causally related to factors other than HIV infection.

Subcutaneous low molecular weight heparin versus subcutaneous unfractionated heparin in the treatment of deep vein thrombosis: a Polish multicenter trial.

In a prospective multicenter trial, 149 consecutive patients with phlebographically proven proximal and/or distal deep vein thrombosis of the leg were randomly allocated to receive subcutaneously for 10 days either low molecular weight heparin CY 216 (Fraxiparine) in a fixed dose or unfractionated heparin (UFH) in doses adjusted according to the activated partial thromboplastin time. Pre- and post-treatment phlebograms were assessed blindly using the Arnesen's score system in 134 patients available for analysis of the treatment efficacy. The mean phlebographic score after 10 days of treatment was significantly decreased in both groups (p less than 0.001) in comparison with the baseline score but the difference in score changes between the two groups was not statistically significant. There was an improvement in 45/68 patients (66%) in the Fraxiparine group and in 32/66 patients (48%) in the UFH group, and an increase in the thrombus size in 10/68 (15%) and 12/66 (18%), respectively. One symptomatic non-fatal pulmonary embolism and one major bleeding episode were observed in the UFH group. During a follow-up period of 3 months, two rethromboses had occurred in the UFH group and none in the Fraxiparine group. It is concluded that subcutaneous fixed dose Fraxiparine is safe and at least as effective as subcutaneous adjusted UFH in the treatment of deep vein thrombosis.

Low molecular weight heparin versus acenocoumarol in the secondary prophylaxis of deep vein thrombosis.

The aim of this study was to determine the efficacy and safety of subcutaneous weight-adjusted dose low molecular weight heparin (LMWH) compared with oral anticoagulant (OA) in the prevention of recurrent venous thromboembolism. In a prospective multicenter trial, 202 patients with symptomatic proximal deep vein thrombosis (DVT) were included. As soon as the diagnosis of DVT was confirmed by phlebography, 101 were randomly assigned to receive LMWH (nadroparin) for secondary prophylaxis and 101 to receive OA (acenocoumarol). Patients in both groups were initially treated with nadroparin in a dose of 85 anti-Xa IU/kg s.c. every 12 h. Secondary prophylaxis with either nadroparin, 85 anti-Xa IU/kg s. c. once daily, or acenocoumarol was continued for at least 3 months. Three patients in the LMWH group and 6 in the OA group were excluded from analysis for various reasons. During the one-year combined secondary prophylaxis and surveillance period, 7 of of the 98 evaluable patients (7.1%) in the LMWH group and 9 of the 95 evaluable patients (9.5%) in the OA group had a documented recurrence of venous thromboembolism (Fisher's exact test, p = 0.61). Of these, 2 patients who received LMWH and 7 patients on acenocoumarol had recurrences in the 3-month period of secondary prophylaxis. Four patients (4.1%) in the LMWH group developed bleeding complications during this study period, as compared with 7 (7.4%) in the OA group (Fisher's exact test, p = 0.37). There were two major bleedings, one in the LMWH group and one in the OA group. Eleven patients died, 5 (5.1%) in the LMWH group and 6 (6.3%) in the OA group. It is concluded that nadroparin in a dose of 85 anti-Xa IU/kg s.c. once daily provides an effective and safe alternative to oral anticoagulants in the secondary prophylaxis of DVT.

Alterations of blood platelet function induced by neutral proteases from human leukocytes.

Washed human platelets are damaged by two neutral proteases from human leukocytes (elastase-like protease, ELP and chymotrypsin-like protease, CLP). The damage is manifested as inhibited aggregation by ristocetin and collagen, and enhanced aggregation by ADP in the presence of fibrinogen. Similarly to alpha-chymotrypsin (alpha-CT), CLP also increases binding of 125I-fibrinogen to platelets and renders platelets aggregable by human fibrinogen. ELP is less effective in this respect possibly due to damage to platelet receptors for fibrinogen. In the plasma medium platelets are not sensitive to leukocytic proteases added at concentrations that provoke some prolongation of the time of plasma clotting by thrombin.

Molecular analysis of hemophilia B in Poland: 12 novel mutations of the factor IX gene.

We examined the molecular basis of factor IX deficiency in 53 unrelated Polish patients with hemophilia B. Heteroduplex analysis and direct sequencing of polymerase chain reaction (PCR) products were applied to identify the gene defect. Forty-three different point mutations were detected in the factor IX gene of 47 patients. There were 29 missense mutations, 9 nonsense mutations, 4 splice site mutations and 1 point mutation in the promoter region. Twelve mutations were novel. The results of this study emphasize a very high degree of heterogeneity of hemophilia B.

Factor V Leiden, prothrombin gene G20210A variant, and methylenetetrahydrofolate reductase C677T genotype in young adults with ischemic stroke.

Ischemic stroke in young adults is a well-known disease, but despite extensive clinical and laboratory investigations, its etiology remains unclear in approximately half of the cases. We examined the prevalence of factor V Leiden, the prothrombin G20210A genotype, and the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene in 100 patients (51 males and 49 females) who survived an ischemic stroke without a cardiac embolic source at an age < or = 45 years, and in 238 healthy control subjects from the same geographic area. The patients were selected for study only if the diagnosis of stroke was documented by computed tomography scan or nuclear magnetic resonance (NMR) of the brain, or both. Heterozygosity for the FV Leiden mutation was found in 3 patients (3.0%) and in 10 control subjects (4.2%). Two patients (2.0%) and five control subjects (2.1%) were heterozygous for the prothrombin G20210A mutation. The frequencies of the MTHFR 677TT, CT, and CC genotypes in the patient group were 12%, 37%, and 51%, respectively, and were not significantly different from those in control subjects (11%, 40%, and 49%, respectively). In conclusion, our results indicate that FV Leiden mutation, prothrombin G20210A genotype, and homozygosity for the C677T mutation in the MTHFR gene are not associated with an increased risk for ischemic stroke in young adults.

[Factor VIII inhibitor appearing in women during delivery]. / Inhibitor czynnika VIII pojawiajacy sie u kobiet w okresie okoloporodowym.

Factor VIII inhibitor is rare, but very serious postpartum complication. Bleeding diathesis caused by this inhibitor is called acquired haemophilia. Three women with postpartum inhibitor to factor VIII and life threatening bleeding were described. In two patients bleeding was controlled by treatment with high doses of human and porcine factor VIII concentrates. One patient died presenting uncontrolled haemorrhagic diathesis. This work presents the problems of the diagnosis, treatment and also the elimination of the factor VIII inhibitor.

[Thrombocytopenia in a patient with hemophilia and HIV infection treated with intravenous immunoglobulin and splenectomy]. / Maloplytkowosc u chorego na hemofilie z zakazeniem HIV leczona dozylnie immunoglobulina i splenektomia.

In a patient with haemophilia B who had developed immune thrombocytopenia following HIV infection, high doses of intravenous immunoglobulin were administered. The therapy brought about only a temporary rise in platelet counts. No beneficial effects were also obtained during a 3-month treatment with corticosteroids. Since there was no response to the conservative therapy, the patient was splenectomized under the cover of factor IX concentrate and the surgical procedure resulted in a complete remission of the thrombocytopenia.

[Current status and future prospects of hemophilia treatment]. / Stan obecny i perspektywy leczenia hemofilii.

Over the past decade, with the use of plasma-derived factor VIII and factor IX, treated with virucidal methods, as well as with recombinant factor VIII, the replacement therapy of hemophilia has been intensified. In developed countries, a majority of patients are being treated at home, and large groups of children benefit from primary prophylaxis. A serious task in these countries for the coming years is the management of patients infected with HIV. In Poland and less-developed countries, the supply of antihemophilic factor concentrates is inadequate. Patients with inhibitor antibodies should be included in programmes of immune tolerance inducement. Many patients who had been multitransfused with cryoprecipate or received lyophilized concentrates before 1985, have developed chronic hepatitis associated with viral infections. About 15-30% show evidence of cirrhosis. Recombinant technologies should be improved and become more accessible in order to provide patients with safe and cheap antihemophilic factor concentrates. A true break-through in the hemophilia treatment would be a repair of the inherited clotting defect with gene therapy.

[Inherited thrombophilia]. / Wrodzona trombofilia.

The prevalence of inherited thrombophilia in the general population (1 in 2,500) is higher than that of hemophilia and related bleeding disorders. Well established causes of thrombophilia include deficiencies of natural coagulation inhibitors: antithrombin III, protein C and protein S. It is likely that other inherited disorders, such as deficiency of the second cofactor for activated protein C, deficiency of heparin cofactor II, hypo- and dysplasminogenemias, dysfibrinogenemias and homocysteinemia, may predispose to thrombosis. This review discusses clinical and laboratory aspects of these disorders and summarizes the management of individuals with inherited thrombophilia.

[Thrombocytopenia associated with HIV infection]. / Maloplytkowosc zwiazana z zakazeniem HIV.

Thrombocytopenia is a common complication of human immunodeficiency virus (HIV) infection. Its pathogenesis has not yet been established. An increased platelet destruction either due to the nonspecific deposition of circulating immune complexes on platelets or to the presence of specific antiplatelet antibodies as well as direct infection of megakaryocytes by HIV with a resulting decrease in platelet production have been reported as possible mechanisms. About 30-50% of patients with moderate thrombocytopenia may show spontaneous remission. Patients with either severe thrombocytopenia (platelet count < 20 x 10(9)/l) or bleeding are usually first treated with corticosteroids or azidothymidine. If improvement does not occur, further therapeutic approaches are the same as for chronic idiopathic thrombocytopenic purpura. HIV-associated thrombocytopenia has no prognostic significance with regard to AIDS risk.

[Preparation and clinical use of a new factor IX concentrate]. / Doswiadczenia w preparatyce i klinicznym stosowaniu nowego koncentratu czynnika IX.

Factor IX concentrate was obtained using DEAE-Sephadex A-50 as an adsorbent. The yield of factor IX in vitro averaged 81%. Each bottle of the concentrate contained 288-512 u. of factor II, 96--360 u. of factor VII, 440--660 u. of factor IX and 256--680 u. of factor X. The results of studies showed trace amounts of factor Xa in the final product, in the range of 0.01--0.04 u/ml. The concentrate was found to be free of thrombin. In the years 1976--1977 the new concentrate was administered 48 times to 10 patients with severe haemophilia B. The in vivo recovery of factor IX was 27--65%. Clinical results of treatment were satisfactory in all patients. No significant changes were observed in platelet count, fibrinogen level and the concentration of fibrinogen degradation products after infusion of the concentrate. The ethanol gelation test was negative in all cases.