Hepatitis C viral clearance and antibody reactivity patterns in persons with haemophilia and other congenital bleeding disorders

We studied hepatitis C virus (HCV) clearance and antibody reactivity patterns in a cohort of 100 haemophiliacs exposed to unsterilized blood products, of whom 25 were antiHCV negative and 75 were antiHCV positive [49 human immunodeficiency virus (HIV) negative and 26 HIV positive]. HCV RNA was measured by the 2.0 bDNA assay and an 'in-house' polymerase chain reaction assay. Antibody reactivity patterns were examined using a recombinant immunoblot assay (RIBA). Prior HCV infection was found in two (8%) of 25 antiHCV negative patients. HCV viraemia persisted in all 26 antiHCV+ patients who were coinfected with HIV. HCV RNA clearance was found in 12 (25%) of 49 antiHCV+, HIV- patients. Viral clearance was associated with younger current age (P < 0.01) and age at infection (P < 0.001), but not with duration of infection or with dose or frequency of clotting factor use. RIBA ratios reflecting an index of each patient's overall reactivity to four HCV epitopes were significantly lower in those with viral clearance (P < 0.0001). Over a period of 15 years, those with viral clearance demonstrated significant loss of reactivity to the NS3, NS4 and NS5 epitopes, while those with viral persistence demonstrated relatively stable reactivities to all epitopes. We conclude that spontaneous HCV RNA clearance in haemophiliacs is age-related and is unlikely to occur in those coinfected with HIV. The loss of antibody reactivity for some epitopes, especially c22 (core), may be a marker for the natural resolution of chronic HCV infection.

A rapid screen for lupus anticoagulant with good discrimination from oral anticoagulants, congenital factor deficiency and heparin, is provided by comparing a sensitive and an insensitive APTT reagent

Lupus anticoagulants (LA) are associated with an increased risk of thrombosis and laboratory detection is of major importance. Various tests are available for LA screening and confirmation, but they differ in sensitivity and specificity, frequently lacking the ability to discriminate between the presence of LA, heparin and oral anticoagulants. We noticed that a patient with LA who had a prolonged activated partial thromboplastin time (APTT) by our routine method, gave a normal result with a different APTT reagent. This latter reagent, which contained soy bean phosphatides (SBP), was compared with a reagent containing rabbit brain phospholipids complexed with kaolin (RBK), for APTT measurement in a variety of patients. There was no significant difference in APTT ratio between the two reagents in plasma samples from healthy normal subjects. In LA samples, SBP gave consistently lower APTT ratios than RBK (mean +/- SEM, 1.04 +/- 0.05 and 2.08 +/- 0.19 for SBP and RBK respectively; P < 0.001). In LA patients receiving oral anticoagulants for antithrombotic prophylaxis or treatment, the APTT ratio was again significantly shorter with SBP (1.60 +/- 0.17 and 3.40 +/- 0.67; P < 0.05). In LA negative patients receiving oral anticoagulants, the relationship was reversed, and a higher APTT ratio was obtained with SBP than RBK (1.61 +/- 0.13 and 1.31 +/- 0.12; P < 0.001). In addition, there were no significant differences in APTT ratios for the two reagents when samples from patients receiving heparin therapy, or patients with acquired factor VIII deficiency or inherited deficiency of factor VIII or IX were studied. The use of the SBP reagent alongside a LA sensitive APTT reagent allows a rapid screening for LA, as well as a confirmation of the phospholipid dependency of the inhibitor.

Prevalence of antibodies against parvovirus B19 in Norwegians with congenital coagulation factor defects treated with plasma products from small donor pools

The seroprevalence of antibodies against parvovirus B19 in 308 Norwegians with coagulation factor defects of different types and severities was assessed by an IgG antibody capture radioimmunoassay (GACRIA). The overall seroprevalence was 62%. The seroprevalence among subjects with different types of coagulation factor defects was related to the type and severity of the coagulation factor defect: severe hemophilia A 64%, moderate and mild hemophilia A 58%, severe hemophilia B 88%, moderate and mild hemophilia B 73%, and von Willebrand's disease 52%. The prevalence of parvovirus B19 antibodies among household contacts and blood donors was 49% and 42% respectively. This study confirms that replacement therapy with coagulation factors is accompanied by an increased risk for acquiring parvovirus B19 infection. However, the prevalence of parvovirus B19 antibodies among Norwegian hemophiliacs is well below the prevalence reported from other countries and probably reflects the small numbers of donors in plasma pools used for the preparation of coagulation factor concentrates.

Fibrinogen Lincoln: a new truncated alpha chain variant with delayed clotting

A patient referred for preoperative investigation of prolonged bleeding and easy bruising was found to have increased thrombin and reptilase times; however, the thrombin catalysed release of fibrinopeptides A and B was normal. Analysis of five other family members, spanning three generations, indicated that three had a similar defect and suggested autosomal dominant inheritance. Non-reducing SDS-PAGE of purified fibrinogen from affected individuals showed that the 340 kD form of their fibrinogen ran as a doublet. SSCP (single-stranded conformational polymorphism) analysis of exon 5 of the A alpha gene, which encodes the C-terminal half of the chain, confirmed the presence of a mutation. Cycle sequencing of PCR amplified DNA revealed a 13 base pair deletion (nt 4758-4770), resulting in a frame-shift at Ala 475, which translates as four new amino acids before terminating at a new stop codon (-476His-Cys-Leu-Ala-Stop). The presence of a circulating truncated A alpha chain was confirmed when SDS-PAGE gels were probed with an alpha chain specific antisera; which showed that the variant A alpha chain comigrated with gamma chains. The truncation results in a variant A alpha chain with a deletion of 131 amino acids (480-610), and four new amino acids at the C-terminal.

Molecular biology of blood coagulation

A complex network of hemostasis proteins maintains the blood flow and integrity of the vascular system. Molecular biology techniques have led to identification and cloning of the corresponding genes, thereby providing the basis for development of various recombinant clotting factor concentrates. Further analysis of these genes allowed for phenotype and genotype correlations in patients with hemorrhagic or thromboembolic disorders and analysis of structure and function relationships of the involved proteins. All these efforts result in a greatly advanced understanding of the hemostatic network. The aim of this article is to illustrate this progress by reporting on the recent results in representative hereditary hemorrhagic and such thromboembolic conditions as hemophilia, von Willebrand disease, and thrombotic disorders.

Low prevalence of thrombophilic coagulation defects in patients with deep vein thrombosis of the upper limbs

While many studies have demonstrated the pathogenetic role of inherited deficiency of natural clotting inhibitors in patients in the development of deep vein thrombosis of lower limbs, no data are available on the prevalence of these abnormalities in patients with upper vein thrombosis. In this study, antithrombin III, protein C, protein S, plasminogen, resistance to activated protein C and factor V Leiden mutation were assayed in 27 consecutive patients with thrombosis of upper extremities. Only two patients (7.4%) showed a congenital defect (one patient with deficiency of protein C, confirmed by family study, and one patient with factor V Leiden mutation). Anticardiolipin antibodies were also measured and four patients (14.8%) had increased levels, confirmed on a subsequent occasion 3 months later. Eighteen out of 27 (67%) had a predisposing or triggering factor, thus emphasizing the role of physical stress in the development of upper vein thrombosis. At variance with what is observed in deep vein thrombosis of the lower limbs, inherited clotting abnormalities seem to be rarely responsible for upper vein thrombosis, whereas anticardiolipin antibodies and cancer are implicated in a significant proportion of cases.

The role of drugs, particularly oral contraceptives, in triggering thrombosis in congenital defects of coagulation inhibitors: a study of six patients

It is well established that pregnancy and puerperium, surgery and trauma may often trigger thrombotic events even in the normal population. On the other hand, patients with congenital deficiency of clotting inhibitors may develop spontaneous thrombotic episodes, although they become often symptomatic when one of the above-mentioned triggering factors is present. We found this to be true in 40 out of 81 symptomatic patients with congenital defects of coagulation inhibitors. In six (15%) of these cases medications (mainly oral contraceptives) triggered the thrombotic event. The incidence of pharmacological factors as a cause of thrombosis is commonly maintained to be low. This study indicates that this is not so and underlines the potential importance of drugs, particularly oral contraceptives, in the pathogenesis of thrombotic events in patients with congenital defects of clotting inhibitors.

Fibrinogen Marburg a new genetic variant of fibrinogen

A new case of congenital dysfibrinogenemia has been discovered in a 20 year old woman, who suffered from a severe postpartal hemorrhage after the delivery of her first child, followed by episodes of thrombosis. Coagulation studies reveal a prolongation of thrombin time, reptilase time was immeasurable. Thromboplastin time and partial thromboplastin time were slightly prolonged. Low fibrinogen levels were obtained by techniques, which depend on the coagulation velocity following addition of thrombin, while immunological procedures gave slightly diminished values of fibrinogen. Patients's fibrinogen had a moderate inhibitory effect on the fibrin formation in normal plasma. However, inhibitors of the fibrinogen-fibrin conversion could not be detected. Coagulation factors were normal, fibriolysis as well. The cause of the coagulation disorder was found to be a defect of the fibrinogen molecule, leading to an abnormal fibrin polmerization of patient's fibrin monomers. The release of the fibrinopeptides in the paperelectrophoresis was normal. The defect of the fibrinogen molecule did not protect from thrombotic complications. The same defect could be found in the lower scale in patient's father, 4 of her 7 brothers and sisters, and her son.

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.

Chromatographic, ultracentrifugal, and related studies of fibrinogen "Baltimore"

Chromatographic, ultracentrifugal, and related studies of the fibrinogen of a patient with a congenital disorder of fibrinogen (fibrinogen "Baltimore" have provided evidence of structural differences from normal.Diethylaminoethyl-cellulose (DEAE-cellulose) gradient elution chromatography demonstrated two major peaks in the elution pattern of fibrinogen Baltimore as was the case for normal fibrinogen. However, the first peak of fibrinogen Baltimore was somewhat broader and more symmetrical and was eluted significantly later in the chromatogram than the corresponding peak of normal fibrinogen. Additionally, in some elution patterns, a shoulder on the ascending limb of peak 1 was present, suggesting the presence of chromatographically "normal" fibrinogen. Thrombin time determinations of eluted column fractions from a chromatogram of propositus fibrinogen supported this conclusion by demonstrating that fibrinogen from the ascending portion of peak 1 behaved functionally more like normal than that later in the chromatogram. Chromatograms of mixtures of propositus and normal fibrinogen confirmed the ability of this technique to distinguish normal from Baltimore fibrinogen. Chromatograms of fibrinogen isolated from two affected daughters displayed the characteristic increased anionic binding of peak 1 fibrinogen. Sedimentation velocity experiments indicated that the S(o) (20, [unk]) of fibrinogen Baltimore was slightly greater (8.13S vs. 7.85S) than that of normal fraction I-4. Differences in concentration dependence (- 0.65 c vs. - 1.30 c for normal) of the sedimentation coefficient could be attributable in part to spatial conformational differences. Molecular sieving experiments in acrylamide gels indicated that the molecular weight of propositus fraction I-2 was about the same as that of normal fibrinogen of comparable solubility (i.e. I-4, mol wt 325,000). Studies of the UV spectra, tyrosine/tryptophan ratios, sialic acid and hexose content, and N-terminal amino acids demonstrated no consistent significant differences from normal fraction I-4.

Natural history of hepatitis C in HIV-negative patients with congenital coagulation disorders

BACKGROUND/AIMS

Knowledge of the natural history of hepatitis C is useful for counselling patients and planning treatment. More data are needed from unselected patient groups without concomitant disease. The aim of this study was to describe the natural history of hepatitis C, two decades after infection, in a homogeneous and well-defined group of HIV-negative patients with congenital coagulation defects who had not received specific therapy for chronic hepatitis C.

METHODS

Medical history, physical examination, laboratory tests and abdominal ultrasonography were performed in 45 HCV-RNA positive, HIV-negative patients, mainly haemophiliacs, from a single centre. Patients were classified according to results of ultrasonography.

RESULTS

Two patients had experienced an episode of variceal bleeding; all others were asymptomatic. None had ascites. HCV-RNA titres were >500000 copies/ml in 23 patients, genotype was 1 in 31 patients. Forty (89%) had elevated transaminases, liver synthesis function was diminished in 7 (16%), and platelet count in 8 (18%). Ultrasonography was normal in 26 (58%) patients, 12 (27%) had isolated splenomegaly, and 7 (16%) had liver nodularity compatible with cirrhosis. Univariate analysis disclosed higher transaminases and gammaGT, higher age at acquisition of infection and higher present age as risk factors for more advanced disease. Of these, only higher present age was an independent predictor in multivariate analysis.

CONCLUSIONS

Median 19 years after infection, 58% of patients had no other signs of liver disease than raised transaminases, 16% had cirrhosis on ultrasonography. Only 2/45 patients had symptomatic disease. Higher present age is the main risk factor for advanced disease in this group.

Transjugular liver biopsy is a safe and effective intervention to guide management for patients with a congenital bleeding disorder infected with hepatitis C

The prevalence of hepatitis C virus (HCV) infection in adult patients with a congenital bleeding disorder (CBD) approaches 95% and is a major cause of morbidity and mortality. Histological examination of the liver remains the cornerstone of management decisions in patients without a CBD. The reluctance to perform liver biopsies in patients with a CBD has been a major limitation in the management of these patients. We are currently the only haemophilia centre in Australasia performing liver biopsies in patients with a CBD for the purpose of guiding prognostic and therapeutic decisions. We report here the results of our centre's experience with transjugular liver biopsy (TJLB) in patients with a CBD. An adequate specimen for histological assessment was attained from all of the patients. There were no major complications recorded. Patients were hospitalized for < or = 48 h for haemostasis prophylaxis. The diagnostic specimen obtained from patients was integral in guiding their future management. We suggest that with a coordinated multidisciplinary approach, TJLB can be performed in patients with a CBD.

Acquired and congenital clotting syndromes

Although Virchow postulated 100 years ago that hypercoagulability states exist, it has only been in recent years that methods of documenting hypercoagulability have been developed. These clotting tendencies can be acquired or congenital. The common causes of acquired clotting tendencies include conditions which result in tissue and cellular damage, shock, transfusion reactions, and tissue necrosis. Certain drugs and drug reactions, and certain disease states which include blood dyscrasias and cancer are also associated with clotting problems. In certain diseases such as homocystinuria, hyperlipidemia, and lupus erythematosus, abnormal clotting tendencies may also develop. Important advances in the recognition of hypercoagulability have come with the documentation that congenital clotting abnormalities exist. Moreover, these abnormalities are proving to be more common than are congenital bleeding syndromes. Patients who appear to have spontaneous clotting manifestations and are under 40 years of age should be screened for one of these abnormalities. These congenital clotting tendencies can be classified as defects in thrombosis inhibitors, dysfibrinogenemias, or defects in fibrinolysis. The first thrombotic inhibitor defect recognized was antithrombin III deficiency which was reported in 1965. Subsequently, Protein C, Protein S, and Heparin cofactor II deficiencies have been recognized as contributing to thrombotic tendencies. Dysfibrinogenemias are relatively rare and most are associated with bleeding problems; however, 11% of the abnormal fibrinogens are associated with a clotting tendency. The reason appears to be that these fibrins are resistant to fibrinolysis. The most common defects which are associated with thrombotic tendencies appear, at the present time, to be due to defects in fibrinolysis. These include hypoplasminogenemia, decreases in plasminogen activator, increases in plasminogen activator inhibitor, and Factor XII deficiency.

Fibrinogen Aarhus--a new case of dysfibrinogenemia

Fibrinogen Aarhus was found in a woman with slightly prolonged whole blood clotting time. The thrombin induced clotting of plasma and purified fibrinogen was much prolonged. Kinetic analysis of FPA and FPB release revealed larger apparent Km and Vmax values for fibrinogen Aarhus than for normal fibrinogen. No clot formation of fibrinogen Aarhus was demonstrated in the presence of Batroxobin and the release of FPA was slower than normal. Upon addition of the clotting enzyme from Agkistrodon contortrix contortrix clotting did occur but the clotting time was much prolonged in comparison with normal fibrinogen. The turbidity of fibrin gels obtained from fibrinogen Aarhus was similar to normal fibrin gels at low thrombin concentrations. Increasing thrombin concentration resulted in appearance of degradation products in the fibrin gels from fibrinogen Aarhus and at the same time a relative increase in turbidity of the gels was observed. Possibly reasons for the slow release of fibrinopeptides, the delayed gelation, and susceptibility to degradation by thrombin are discussed.

Coagulation Defects

The present understanding of the coagulation process emphasizes the final common pathway and the proteolytic systems that result in the degradation of formed clots and the prevention of unwanted clot formations, as well as a variety of defense systems that include tissue repair, autoimmune processes, arteriosclerosis, tumor growth, the spread of metastases, and defense systems against micro-organisms. This article discusses diagnosis and management of some of the most common bleeding disorders. The goals are to provide a simple guide on how best to manage patients afflicted with congenital or acquired clotting abnormalities during the perioperative period, present a brief overview of the methods of testing and monitoring the coagulation defects, and discuss the appropriate pharmacologic or blood component therapies for each disease.

Immune response of patients with congenital coagulation disorders to hepatitis B vaccine: suboptimal response and human immunodeficiency virus infection

Seventy-eight patients with congenital coagulation disorders were treated with hepatitis B vaccine either subcutaneously or intradermally. All the children (eight vaccinated subcutaneously and eight vaccinated intradermally) responded. Seventeen of 19 (90%) anti-HIV-negative adults vaccinated subcutaneously and 14/25 (56%) anti-HIV-negative adults vaccinated intradermally showed an immune response. At 24 months, the anti-HBs level was greater than 10 IU/l in all children vaccinated subcutaneously, 83% of children vaccinated intradermally, 77% of adults vaccinated subcutaneously, and 55% of adults vaccinated intradermally. Eight of 15 (53%) adult patients who were anti-HIV positive were also anti-HBc positive before vaccination and 6/8 (75%) failed to produce an amnestic response to vaccine. Subcutaneous vaccination with regular monitoring of anti-HBs levels and appropriate boosting is recommended.

Surgery in patients with congenital disorders of blood coagulation

Surgical procedures on patients with congenital disorders of blood coagulation can be performed with a high degree of confidence and an acceptable incidence of complications. During the period 1960-1975, 42 patients with congenital disorders of blood coagulation underwent 94 operative procedures at the New York Hopital-Cornell Medical Center. The coagulation defect was diagnosed preoperatively, in nearly all patients. Careful hematologic management, including specific factor replacement, is essential. The importance of meticulous hemostasis at surgery and careful monitoring of blood coagulation in the postoperative period is strongly emphasized.

Neonate with a fibrosarcoma and consumptive coagulopathy

We report a case of a neonate with a congenital tumor on the left palm. The patient had a grapefruit-sized tumor and coagulopathy at birth and was presumed to have a hemangioendothelioma with associated Kasabach-Merritt phenomenon. When the tumor failed to respond to systemic steroids, a biopsy specimen was taken, revealing a fibrosarcoma. We describe this case to highlight the importance of including rare tumors, such as fibrosarcomas, in the clinical differential when evaluating a congenital tumor with associated coagulopathy. We discuss subtle differences in clinical presentations that might aid in differentiating vascular tumors from fibrosarcomas.