Hepatitis A immunization in HIV-infected haemophilic patients

Forty-seven HIV-infected haemophilic patients were entered into a hepatitis A vaccination programme. 10 patients (21%) were lgG seropositive for hepatitis A consistent with past exposure. Of the 37 patients offered vaccination, one refused and 31 completed the vaccination course, 17/13 (55%) seroconverted, nine after the second and eight after the third injection, and 14 patients failed to seroconvert. The CD4 lymphocyte counts immediately prior to vaccination were significantly higher in the patients who developed immunity compared to the nonresponders (median CD4 count in the immune group 380 × 10(6) /1 (range 170-1290), median CD4 count in nonimmune group 110 × 10(6) /1 (range 10-590), P== 0.003). No patient with a CD4 count < 170 × 10(6) /1 seroconverted and five patients with well-preserved CD4 counts also failed to seroconvert. We conclude that HIV-infected haemophilic patients, especially those with more advanced disease, have an impaired response to hepatitis A vaccination. Due to the likely failure of response in patients with CD4 counts < 150 × 10(6) /1, it is reasonable not to include these patients in a hepatitis A vaccination programme.

The UK Haemophilia Doctors Organisation triennial audit of UK Comprehensive Care Haemophilia Centres

Under the auspices of the United Kingdom Haemophilia Doctors Organisation (UKHCDO) the UK Comprehensive Care Haemophilia Centres (CCCs) have undergone a three yearly formal audit assessment since 1993. This report describes the evolution of the audit process and details the findings of the most recent audit round, the sixth since inception. The audit reports from the 2009 audit round were reviewed by the audit organizing group and a structured analysis of the data was compiled. CCCs in the UK offer a high standard of comprehensive care services. The main areas of concern were the state of the premises (seven centres), lack of dental services (seven centres), physiotherapy (seven centres) and social work support (11 centres). Major concerns were identified at eight centres requiring a formal letter from the chairman of UKHCDO to the chief executive of the host trust. Since inception of the triennial audit process centre report recommendations have resulted in major improvements in the services available at UK CCCs. The audit process is considered to be a highly effective means of improving the quality of care for patients with bleeding disorders and can be used as a model for the introduction of a similar process in other countries.

UKHCDO guidelines on the management of HCV in patients with hereditary bleeding disorders 2011

Chronic HCV infection continues to be of significant clinical importance in patients with hereditary bleeding disorders. This guideline provides information on the recent advances in the investigation and treatment of HCV infection and gives GRADE system based recommendations on the management of the infection in this patient group.

Spontaneous resolution of acquired factor V inhibitor associated with ovarian carcinoma

A 74-year-old lady who presented initially with loin pain and haematuria, then melaena was found to have a prothrombin time ratio (PTR) > 10 and activated partial thromboplastin time ratio (APTTR) > 7. A factor V inhibitor was diagnosed. She was managed with supportive care and the FV inhibitor resolved. A few weeks later she developed abdominal swelling and ascites and was found to have an ovarian tumour. This is the first case, as far as we are aware, of a malignancy-associated FV antibody that has spontaneously remitted before overt presentation of the tumour and illustrates the value of adopting an expectant approach to the management of acquired FV inhibitors.

The prevalence of the cysteine1584 variant of von Willebrand factor is increased in type 1 von Willebrand disease: co-segregation with increased susceptibility to ADAMTS13 proteolysis but not clinical phenotype

The molecular pathogenesis of type 1 von Willebrand disease (VWD) is uncertain in most patients. We examined 30 type 1 VWD families in the UK Haemophilia Centre Doctors' Organization study. Heterozygosity for Y/C1584 was present in eight of 30 (27%) families and 19 of 76 (25%) individuals with type 1 VWD recruited into the study. Eighteen (95%) of these 19 individuals were blood group O. C1584 did not co-segregate with VWD in four families, and co-segregated in one family; the results were equivocal in three families. In all families increased susceptibility of von Willebrand factor (VWF) to a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS) 13 proteolysis co-segregated with C1584 in affected and unaffected individuals. These data show that C1584, associated with blood group O, is prevalent among patients with type 1 VWD but not necessarily causative of disease and should not be used in isolation to diagnose VWD. Increased susceptibility of C1584 VWF to ADAMTS13 proteolysis may be physiologically significant and increase an individual's risk of bleeding and presenting with VWD.

The rare coagulation disorders - review with guidelines for management from the United Kingdom Haemophilia Centre Doctors' Organisation

The rare coagulation disorders are heritable abnormalities of haemostasis that may present significant difficulties in diagnosis and management. This review summarizes the current literature for disorders of fibrinogen, and deficiencies of prothrombin, factor V, FV + VIII, FVII, FX, the combined vitamin K-dependent factors, FXI and FXIII. Based on both collective clinical experience and the literature, guidelines for management of bleeding complications are suggested with specific advice for surgery, spontaneous bleeding, management of pregnancy and the neonate. We have chosen to include a section on Ehlers-Danlos Syndrome because haematologists may be consulted about bleeding manifestations in such patients.

HIV and HCV coinfection in haemophilia

A substantial number of haemophilic patients are infected with both human immunodeficiency virus (HIV) and hepatitis C (HCV). HIV has been shown to accelerate the course of HCV chronic liver disease and there is evidence that HCV infection may worsen the prognosis of HIV. As many HIV infected patients are stable on highly active antiretroviral therapy (HAART) HCV should be actively managed in coinfected individuals. Pegylated interferon (Peg-IFN)/ribavirin combination therapy is the treatment of choice for HCV infection and should be considered in patients with stable HIV on or off HAART with CD4 counts >200 x 10(6)/l. Results of on-going trials of combination therapy in coinfected individuals are awaited. For coinfected patients with end stage liver disease who are stable on HAART liver transplantation should be considered.

Evidence for the use of activated prothrombin complex concentrates (aPCCs) in the treatment of patients with haemophilia and inhibitors

FEIBA and Autoplex T have been used to control bleeding in patients with factor VIII or IX inhibitors for over 25 years. The major components of FEIBA are thought to be activated factor X and prothrombin, whereas the main active components in Autoplex T are thought to be activated factors IX and VII. Both products have been found to effectively control approximately 80% of bleeds involving joints and soft tissues. Published experience of their use in surgery is limited. Thrombotic complications have been reported with high dose FEIBA therapy and have led to maximum dosage guidelines for this product.

Haemophilia 2002: emerging risks of treatment

Haemophilia care and treatment products have greatly improved over the past 2 decades. Transitions in treatment produced by these changes were accompanied by the emergence of unexpected risks and new complications. In order to provide the best comprehensive care to patients with haemophilia, healthcare providers periodically need to re-evaluate and adjust their management and therapeutic products to prevent or minimize the effects produced by the emerging issues. For example, reducing the effects of infectious agents remains the highest priority for the haemophilia community because of the high level of morbidity and mortality that has resulted from earlier therapeutic agents. In many countries, the goal has been to achieve absolute zero risk for infectious agents. In some instances, the screening procedures to achieve these goals reduced the availability of plasma needed for manufactured derivatives and produced another emerging risk, shortages of clotting factor preparations. Similarly, better diagnostic methods identified other potential agents that were not inactivated by current technology. Likewise, immune tolerance regimens and the prophylactic management of haemophilia introduced different therapeutic delivery systems with their own risks. The drugs used to manage diseases such as human immunodeficiency virus (HIV), which were transmitted by products manufactured before mid-1980, create their own set of risks for this community. Topical emerging risks of treatment, including variant Creutzfeldt-Jakob disease, an assessment of its risks and impact, the complications of using indwelling catheters, and the role of protease inhibitors used to treat HIV may have on bleeding complications of haemophilia are discussed.

Elective surgery on factor VIII inhibitor patients using continuous infusion of recombinant activated factor VII: plasma factor VII activity of 10 IU/ml is associated with an increased incidence of bleeding

We examined recombinant activated factor VII (rVIIa) administered by continuous infusion to eight patients with inhibitors to factor VIII, undergoing elective surgery. rVIIa was infused at a fixed rate of 16.5 microg/kg/h for a median of 13.5 days (range 1-26). There was effective haemostasis at this infusion rate in only one of two minor procedures and two of six major operations. Three patients experienced excessive bleeding despite plasma factor VII activity around 10 IU/ml. Serious bleeding occurred in two other patients caused by procedural errors unrelated to rVIIa and required re-operation. The median rVIIa clearance on day 1 was 57 ml/h/kg (range 18-100) and on day 3 was 100 ml/h/kg (range 61-200). Clearance on the final infusion day was not significantly different from day 3. The infusion did not induce pathological activation of the coagulation mechanism. The only thrombotic adverse events were two episodes of superficial thrombophlebitis of the infused vein in one subject. In conclusion, the 16.5 microg/kg/h infusion rate reliably achieves plasma factor VII activity levels of 10 IU/ml, but this level does not provide reliable haemostasis.

Protease inhibitor therapy and bleeding

Shortly after the introduction of protease inhibitor drugs (PIs) for the treatment of human immunodeficiency virus infection an association between these drugs and an increased bleeding tendency in patients with hereditary bleeding disorders was observed. Not only do patients experience an increased bleed frequency in usual sites, but bleeds can also occur in unusual places such as the finger joints. Mucus membrane bleeding and haematuria are also common. Ritonavir appears to be associated with the highest risk of bleeding followed by indinavir. As yet there has not been enough experience with the newer PIs to assess fully their potential to induce increased bleeding, although nelfinavir seems to pose less of a risk than the original PIs. PI-associated bleeds tend to be more resistant to factor concentrate treatment and periods of prophylaxis may be required in individuals with frequent persistent bleeds. Patients continuing on PI therapy tend to develop a tolerance to this adverse effect with time. The mechanism of the bleeding tendency has not been elucidated. There is no consistent evidence of a disturbance of coagulation, fibrinolysis or platelet function which raises the possibility that PIs may exert a direct local effect on blood vessels. It is very important that this class-specific side-effect is recognized and understood by both treaters and patients.

Deficiency of natural anticoagulant proteins C, S, and antithrombin in portal vein thrombosis: a secondary phenomenon?

BACKGROUND

Hereditary deficiencies of natural anticoagulant proteins are implicated in the pathogenesis of portal vein thrombosis (PVT). Secondary deficiencies of these proteins have also been reported in PVT, making interpretation of concentrations difficult.

AIMS

To characterise the coagulation profiles in adult patients with PVT and to investigate the possible mechanisms of natural anticoagulant protein deficiency.

PATIENTS

Twenty nine adult patients with portal hypertension caused by PVT, and normal biochemical liver function tests.

METHODS

Routine coagulation profiles and concentrations of proteins C, S, and antithrombin were measured; where indicated, corresponding concentrations in parents were also measured. Synchronous peripheral and hepatic or splenic vein concentrations were compared in seven patients undergoing interventional procedures, as were peripheral concentrations before and after shunt surgery in three patients.

RESULTS

Deficiencies of one or more of the natural anticoagulant proteins occurred in 18 patients (62%), with six patients having combined deficiency of all three proteins. There were strong correlations between prothrombin and partial thromboplastin time ratios and concentrations of natural anticoagulant proteins. Family studies in nine cases of anticoagulant protein deficiency revealed possible hereditary deficiency in only three cases, and significantly lower concentrations of anticoagulant proteins in all PVT cases compared with parents. Levels of anticoagulant proteins tended to be lower in hepatic veins but higher in splenic veins compared with peripheral vein concentrations. Peripheral concentrations decreased after shunt surgery.

CONCLUSIONS

Deficiency of natural anticoagulant proteins is common in PVT and is probably a secondary phenomenon in most cases, occurring as part of a global disturbance of coagulation variables. The mechanism for this remains unclear but may result from a combination of reduced hepatic blood flow and portosystemic shunting itself.

Combined alpha interferon and ribavirin for the treatment of hepatitis C in patients with hereditary bleeding disorders

Patients with hereditary bleeding disorders who received non-virally inactivated plasma-derived clotting factor concentrates before the mid-1980s invariably became infected with hepatitis C virus (HCV). Therapy with interferon alpha (IFN-alpha) alone has been disappointing in this group. We conducted an open-label study, using a combination of IFN-alpha2b (3 million units three times per week) and ribavirin 1-1.2 g/d in 28 patients with hereditary bleeding disorders. Twenty-one of the 28 patients had liver biopsy-confirmed chronic hepatitis (median histological activity index 5; range 1-10) and all patients were HCV RNA positive by PCR. Virological response rate to therapy at 3 months was 82% (23 out of 28). Three HIV co-infected patients showed an early virological response with loss of HCV RNA, but two subsequently relapsed after 3 and 6 months of therapy. Four patients stopped treatment early (one at 4, one at 7 and two at 9 months) because of treatment-related side effects, although three of these have maintained a virological response. Seventeen patients completed the 48-week course. Twenty of the 28 (71%) treated have had a durable virological response with a median follow-up of 16 months (range 1-24). Combination therapy represents a significant advance in the treatment of hepatitis C in patients with hereditary bleeding disorders.

Increased bleeding associated with protease inhibitor therapy in HIV-positive patients with bleeding disorders

The use of protease inhibitor (PI) drugs in treatment regimens for HIV-infected patients with hereditary bleeding disorders has been associated with an increased bleeding tendency. To characterize the nature of this bleeding tendency, a retrospective case record analysis was performed on 67 HIV-positive patients with hereditary bleeding disorders who had been treated with PI therapy. 34 patients (51%) developed an increased bleeding tendency on PI therapy, usually within the first few weeks of treatment. As well as an increase in usual joint bleeds, patients developed spontaneous atypical small joint, soft tissue and muscle bleeds. Haematuria was also common. Bleeding episodes tended to respond suboptimally to factor concentrate replacement. Ritonavir was most likely to be associated with bleeding. Nine patients switched first-line PI therapy as a direct consequence of bleeding and seven had no further bleeding problem on their second PI. Factor concentrate usage was significantly increased during the first 6 months of PI therapy compared to the 6 months preceeding treatment. PI therapy is frequently associated with increased bleeding in patients with hereditary bleeding disorders. The mechanism of the bleeding tendency remains to be elucidated.

Nasal haemophilic pseudotumour

Haemophilic pseudotumour or haemophilic cyst is a rare complication of haemophilia, occurring in one to two per cent of individuals with a severe factor VIII or IX deficiency. We report a case of a haemophilic pseudotumour in a hitherto unreported site, the bony nasal pyramid, and believe this case is also unique on account of it having occurred in a patient with mild haemophilia. The diagnosis and treatment of this rare condition is also reviewed.

A novel ELISA-based primer extension assay for the detection of the factor V Leiden mutation

We describe an enzyme-linked immunosorbent assay (ELISA) based primer extension method for the detection of the factor V Leiden (FVL) mutation. The wild-type nucleotide at position 1691 or the mutant nucleotide at the complementary position on the antisense strand were detected by the incorporation of biotinylated complementary bases onto fluorescein isothiocyanate (FITC) labelled mini-sequence primers with specificity for the sense and antisense gene segments downstream from the bases adjacent to position 1691. The reactions took place in pairs of tubes containing the complementary bases to either the wild-type or mutant nucleotide respectively. Primer extension products from each reaction tube pair which have incorporated biotinylated bases were then captured in streptavidin-coated microtitre plate wells and detected colourimetrically using an ELISA procedure. 200 patient samples were tested to validate the assay and there was complete genotypic agreement between the ELISA method and restriction site analysis using Mnl I (137 wild type, 55 FVL heterozygotes and eight homozygotes). The method utilizes non-radioactive reagents and does not require electrophoretic techniques. It is therefore a safe, simple and rapid assay which lends itself to automation.

Hepatitis C viral load, genotype and histological severity in patients with bleeding disorders

We report the relationship between hepatitis C virus (HCV) titre, liver histology and HCV genotype in patients with bleeding disorders. One hundred and thirty-two RIBA-2-positive patients, including 56 who were also HIV positive, were identified at our centre. Fifty of these patients, including nine who were HIV infected, underwent percutaneous liver biopsy. Liver histology was assessed using a modified histological activity index (HAI). Qualitative serum HCV PCR was positive in 87 (87%) of the 101 patients tested including 43 of 50 biopsied patients. HCV RNA titres, measured by quantitative PCR, were significantly higher in HIV-positive patients compared with HIV-negative patients (P < 0.05) but were not related to HAI, mean factor concentrate usage, duration of HCV infection or HCV genotype. There was no relationship between HCV genotype and HAI. Qualitative HCV PCR was positive in 30 of 43 liver biopsies tested. Biopsy PCR-positive and -negative cohorts were not distinguished by HAI or serum HCV titre. We conclude that although serum HCV PCR is useful in confirming the presence of HCV infection in patients with bleeding disorders, little meaningful information concerning the severity of the disease can be obtained from serum HCV quantification.

Relapsing thrombotic thrombocytopenic purpura in association with recurrent pancreatitis

We report the case of a 28-year-old woman who presented with two episodes of acute pancreatitis 3 years apart both of which were complicated by the development of thrombotic thrombocytopenic purpura (TTP). On each occasion the TTP was successfully managed with plasmapheresis. Although TTP has been reported as causing acute pancreatitis, the induction of TTP by pancreatitis is rare. As far as we are aware this is the first reported case of recurrent TTP in association with acute pancreatitis. It is possible that circulating pancreatic proteases may have induced the TTP by modifying von Willebrand factor enabling spontaneous platelet membrane receptor binding resulting in intravascular platelet aggregation.

Epidemiology of infection with Epstein-Barr virus types 1 and 2: lessons from the study of a T-cell-immunocompromised hemophilic cohort

In apparent contrast to earlier work on Epstein-Barr virus (EBV) carriage in the general Caucasian population, in vitro virus isolations from human immunodeficiency virus (HIV)-positive male homosexual cohorts have shown frequent examples of multiple EBV infection and an overall prevalence of type 2 EBV strains exceeding 30%. Here we ask to what extent these findings might hold true in another T-cell-immunocompromised cohort, HIV-positive hemophilic patients. Resident EBV strains were rescued within lymphoblastoid cell lines derived from the blood and throat washings of 39 such individuals, using the same in vitro protocols of virus isolation as for the homosexual cohort. A mean of 19 independent cell lines was made per patient, and in each case the resident virus was characterized by PCR-based viral genomic analysis and by immunoblotting to reveal the viral "EBNAprint." By these criteria a significant proportion (14 of 39) of the hemophilic cohort carried more than one EBV strain, suggesting that T-cell impairment does indeed sensitize virus carriers to reinfection with new strains of exogenously transmitted virus. However, the overall incidence of type 2 EBV infection was 10%, which is close to that observed in the earlier work with healthy carriers and substantially lower than that seen in HIV-positive homosexuals. We infer that type 2 EBV is relatively rare in the general Caucasian population but has become endemic in the homosexual community.

von Willebrand disease and its management in oral and maxillofacial surgery

von Willebrand disease (vWD) is the most common of the hereditary disorders of coagulation. We describe the pathophysiology, diagnosis and the new simplified classification of the disorder and discuss the management of patients about to undergo dental procedures and maxillofacial surgery. Close collaboration between oral and maxillofacial surgeons and haematologists in the management of patients with vWD is essential.

Hyperhomocysteinaemia and vascular disease

The amino-acid homocysteine plays a crucial role in cell metabolism. It participates in the remethylation pathway enabling maintenance of adequate cellular levels of methionine or is catabolized by transsulphuration. A number of hereditary defects in the enzymes involved in homocysteine metabolism and acquired deficiencies in the vitamin cofactors of these enzymes are associated with the development of hyperhomocysteinaemia. The association between high circulating homocysteine levels and premature vascular thrombosis is well established in individuals with hereditary homocystinuria. There is now good epidemiological evidence that mild hyperhomocysteinaemia is an independent risk factor in the development of arterial disease and venous thrombosis although the causes of the elevated plasma homocysteine are unclear. A good candidate is homozygosity for the common thermolabile variant of methylenetetrahydrofolate reductase but the evidence for a causative association is conflicting. A number of in vitro effects of homocysteine on vascular endothelium, platelets and coagulation have been described which may predispose to vascular disease but the exact in vivo mechanisms remain to be elucidated. Dietary folate supplementation may normalize homocysteine in hyperhomocysteinaemic individuals and modify the risk of vascular disease.

Hepatitis G virus infection in patients with bleeding disorders

Eighty-two patients with bleeding, disorders registered with our centre were screened for infection with hepatitis G virus (HGV). 80 patients were positive for hepatitis C (HCV) antibodies, 66 of whom (83%) were HCV PCR positive. 11 patients (13%) were HGV RNA-positive, a similar prevalence rate to that of other studies of patients with bleeding disorders who received factor concentrates prior to the introduction of viral inactivation procedures. There was no significant difference in histological activity index (HAI) between the 10 HGV RNA-positive and the 31 HGV RNA-negative patients who underwent liver biopsy for assessment of HCV infection (median HAI scores 5.5, range 2-10 and four, range 0-10 respectively, P = 0.07). One patient in each group had established cirrhosis. In patients who underwent HCV quantitation there was no significant difference in HCV viral titre between HGV RNA-positive and negative patients (median HCV titre in HGV RNA-positive patients 2.10 x 10(5) DNA copies/ml (n = 8) range 4.17 x 10(2) to 4.17 x 10(6), median HCV titre in HGV RNA-negative patients 3.33 x 10(5) (n = 31) range 1.00 x 10(3) to 6.67 x 10(6), P = 0.68). In this study there was no evidence that individuals co-infected with HGV and HCV have more severe liver disease than those infected with HCV alone.

Priapism in a patient with protein C deficiency

We present the case of a patient with classical protein C deficiency presenting with acute priapism during warfarinization for thrombophlebitis. Priapism is a well-recognized complication of a number of conditions including sickle cell disease and haematological malignancies, but to our knowledge it has not previously been reported in association with protein C deficiency. This case highlights the potential dangers of initiating oral anticoagulant therapy using conventional loading dose regimens in patients with protein C deficiency.

Prevalence of the factor V Leiden mutation in hepatic and portal vein thrombosis

BACKGROUND

The factor V Leiden (FVL) mutation has been shown to be the most frequent cause of hereditary thrombophilia. The prevalence of the mutation in patients with Budd-Chiari syndrome (BCS) and portal vein thrombosis (PVT) has not been fully elucidated.

AIMS

To investigate the association between the FVL mutation and BCS and PVT.

PATIENTS

Thirty patients with BCS, 32 patients with PVT, and a control group of 54 patients with liver disorders and no history of thrombosis.

METHODS

The factor V gene was analysed for the presence of the FVL mutation by a polymerase chain reaction (PCR) technique. The presence of the mutation was confirmed by DNA sequencing.

RESULTS

Seven (23%) patients with BCS, one (3%) patient with PVT, and three (6%) patients in the control group were identified as having the FVL mutation. There of the BCS patients had coexisting hypercoagulable states. The prevalence of the FVL mutation was significantly higher in patients with BCS compared with patients with PVT and controls (p < 0.04). The FVL mutation was the second most common aetiology associated with BCS.

CONCLUSION

The FVL mutation is an important factor in the pathogenesis of BCS and screening for the disorder must be included in the investigation of patients presenting with this condition. In contrast, the FVL mutation is not a major predisposing factor in the pathogenesis of PVT.

Hematological consequences of profound hypothermic circulatory arrest and aortic dissection

The lower temperatures utilized during profound hypothermic circulatory arrest (PHCA) surgery may exacerbate the hypothermia associated platelet and clotting factor dysfunction observed in conventional cardiopulmonary bypass (CPB) procedures. Hypothermia has been shown to impair the activity of the enzymes involved in the platelet activation pathways and to reduce the enzymatic activity of clotting factors upon coagulation activation. The resulting retardation of the generation of fibrin/platelet clot compounded by the presence of heparin may contribute significantly to a bleeding tendency. Excessive fibrinolytic activity may disrupt surgical wound thrombi and exacerbate haemorrhage. There is good evidence that the fibrinolytic activity, mediated predominantly by tissue plasminogen activator (tPA), is a secondary response to thrombin generated by coagulation activation, which is ongoing during CPB despite full heparinization. The effects of hypothermia on the fibrinolytic response remain to be clarified and the extent to which the lower temperatures and blood stasis associated with PHCA moderate this response is unknown. Despite impairment of coagulation activation by hypothermia there appears to be a shift in the hemostatic balance towards thrombosis presumably as a consequence of endothelial cell injury by both hypothermia and stasis induced ischemia. There is evidence that widespread microvascular thrombus deposition may occur as a consequence of stasis in patients undergoing PHCA and that this might result in vascular occlusion and end organ damage. Although it is not uncommon to find laboratory evidence of disseminated intravascular coagulation (DIC) in patients presenting with aortic aneurysm rupture or dissection, the incidence of clinically overt DIC resulting in bleeding is low. The underlying hemostatic disturbance however may contribute to the surgery-associated bleeding diathesis.

A combined management protocol for patients with coagulation disorders infected with hepatitis C virus

The case notes of 394 adults with bleeding disorders registered at our centre together with those of the 72 patients who had died since 1971 were reviewed. 36/72 deceased patients had evidence of HCV infection. Liver decompensation was present at time of death in six. 274 (70%) of the currently registered patients had received factor concentrate or cryoprecipitate and 174 of these were screened for HCV infection. 76% of tested patients were RIBA positive. 87% of RIBA-positive patients were RT-PCR positive. 50 RIBA-positive patients, including nine who were HIV infected, have undergone percutaneous liver biopsy following appropriate factor infusion with no complication. The biopsy was assessed using a Histological Activity Index (HAI) ranging from 0 to 13. Patients with HAI > or = 6 were offered treatment with interferon. Patients with HAI < 6 were followed up with a view to re-biopsy in 2-3 years to assess progression. The median HAI was 4.5 (range 0-10) with HAI > or = 6 in 13 cases (27%). HAI was not correlated with duration of infection. haemophilia severity. RT-PCR status. HIV status or HCV genotype. Liver biopsy, a safe procedure in our hands, is an important investigation in HCV-infected patients to assess suitability for interferon therapy.

The investigation of a patient with unexpected venous thrombosis

Over recent years a number of hereditary and acquired defects of the circulation's natural anticoagulant mechanisms have been characterised and shown to predispose affected individuals to thrombosis. It is important to attempt to diagnose a thrombophilia state in patients with a thrombotic tendency in order to provide appropriate management, especially during at-risk situations, both for themselves and asymptomatic relatives identified through family studies. This review defines the patients who should be investigated for an underlying thrombophilia state and describes the hereditary and acquired disorders which should be screened for within an investigation profile. The recently identified factor V Leiden mutation which appears to be the most common hereditary cause of a thrombotic tendency is described in detail and descriptions of the more established thrombophilia states are included. Although the factor V Leiden mutation accounts for a significant proportion of cases fulfilling the criteria for thrombophilia screening, a predisposing cause for thrombosis remains unidentifiable in a large number of patients making it likely that over the years to come new thrombophilia states will continue to be identified.

Didanosine treatment of haemophilic patients infected with HIV

Twenty-six haemophilic patients with advanced HIV infection who had developed resistance or intolerance to zidovudine were treated with didanosine (ddI). 11 patients continue to take ddI at a median time of 14 months from commencement (range 7-18 months). Five of these patients showed an increase in CD4 lymphocyte count, reaching a maximum at a median time of 4 months. Four patients with HIV-related symptoms improved clinically. In general, the CD4 count and clinical improvements were not sustained. 11 patients discontinued ddI after a median of 3 months (range 3 days to 10 months), most commonly due to gastrointestinal side-effects. No case of pancreatitis or peripheral neuropathy was seen. Six patients, all with very advanced HIV disease, died. HIV-infected haemophilic patients who become resistant or intolerant to zidovudine may derive benefit from ddI, although this is usually transient.

Haemostatic problems in acute leukaemia

Disseminated intravascular coagulation (DIC) is a frequent complication of acute leukaemia, in particular acute promyelocytic leukaemia. Although procoagulant substances released from leukaemic blast cells may induce DIC by activating conventional coagulation pathways, there is increasing evidence to suggest that direct activation of fibrinogen by proteases released from blast cells may be the predominant mechanism by which DIC is initiated. Primary fibrinolysis has also been proposed as the cause of the haemorrhagic diathesis in some cases of acute leukaemia. Although plasminogen activators have been demonstrated in leukaemic blast cells supporting this view, cases of primary fibrinolysis would appear to be rare. A bleeding tendency attributed to primary fibrinolysis may more often be the result of an exaggerated fibrinolytic response secondary to DIC. The main strategies of treatment for leukaemia associated DIC are rapid initiation of chemotherapy and vigorous blood product support until the DIC resolves once the blast cells have been eradicated. The role of heparin in the management of leukaemia associated DIC remains controversial. There is recent evidence to suggest that heparin therapy does reduce the incidence of haemorrhagic death although it has been recommended that relatively low intravenous doses should be administered initially to reduce the risk of heparin induced haemorrhage.

A comparative evaluation of assays for markers of activated coagulation and/or fibrinolysis: thrombin-antithrombin complex, D-dimer and fibrinogen/fibrin fragment E antigen

Measurements were made of levels of D-dimer in plasma and serum, thrombin-antithrombin complex (TAT) in plasma and fibrinogen/fibrin fragment E antigen (FgE) in serum in a normal healthy control group and in patients with a range of disorders associated with hypercoagulability. Levels were determined in 31 normal healthy controls, 30 patients with disseminated intravascular coagulation (DIC), 21 patients with deep venous thrombosis (DVT), 27 patients with myocardial infarction (MI), 26 patients with acute leukaemia and 56 patients with liver disease. Considering all subjects, significant correlations were established between the results of all assays. Notably high correlations (r greater than 0.9) were established between plasma and serum levels of D-dimer, between plasma levels of D-dimer and serum levels of FgE, and between serum levels of D-dimer and FgE. All assays showed very high discrimination (sensitivity) between the normal control group and patients with DIC (97-100%), but there were marked differences between the assays in sensitivity for DVT and MI. In general, the FgE assay was more sensitive than the D-dimer assay, whilst both the FgE and D-dimer assays were more sensitive than the TAT assay. The same trends were apparent in the capability of the assays to discriminate between the normal control group and patients with acute leukaemia and liver disease: disorders with an unknown prevalence of activation of coagulation/fibrinolysis. Our results indicated that measurements of fibrinogen/fibrin degradation products (FDPs) in serum were almost unaffected by artefacts. The data further suggested that the broad-spectrum FgE assay was better than the more specific D-dimer assay in detecting clinical hypercoagulability. Our study showed that, in the clinical conditions examined, FDPs were more effective markers of hypercoagulability than TAT.

Coagulation disturbances following ascites recirculation

To investigate the effects of extra-corporeal ascites recirculation on coagulation, several coagulation variables were measured in ascitic return fluid and plasma before, during and after this procedure in 16 patients with diuretic resistant ascites. Small but significant reductions in plasma fibrinogen levels and platelet counts and increases in plasma X-oligomer were observed during and after the procedure compared with before. These findings are consistent with the view that ascites recirculation induces disseminated intravascular coagulation although this would appear to be only mild and of no clinical significance in the majority of patients. Although increased levels of activated factor VII were observed in ascitic fluid indicating activation of the extrinsic pathway of coagulation, a significant increase in plasma activated factor VII during the procedure was not demonstrated. Increased fibrinolytic activity was observed in ascitic fluid due to the presence of tissue plasminogen activator. Increased X-oligomer levels were observed in ascitic fluid indicating that lysis of cross-linked fibrin is also an active process within ascites.

Plasma D-dimer levels and their relationship to serum fibrinogen/fibrin degradation products in hypercoagulable states

Plasma D-dimer was measured and compared with serum fibrinogen/fibrin degradation product levels (FDPs) in patients with disseminated intravascular coagulation (DIC) and other conditions associated with a hypercoagulable state. D-dimer (N less than 200 ng/ml) was elevated in all 43 patients with DIC, in 48 of 59 patients with liver disease, in 22 of 27 patients with acute leukaemia at presentation, in 17 of 23 patients with malignant disease, in 29 of 39 women in the third trimester of a complicated pregnancy, in 17 of 18 patients with deep venous thrombosis and in only four of 27 patients with acute myocardial infarction. There was a significant correlation between plasma D-dimer and serum FDP levels (P less than 0.01) as follows; DIC: r = 0.58, liver disease: r = 0.57, acute leukaemia: r = 0.84, malignancy: r = 0.87. The frequent elevation of D-dimer observed in liver disease, acute leukaemia, malignancy and complicated pregnancy indicates that a hypercoagulable state is a common occurrence in these conditions although in liver disease elevated levels resulting from a failure of normal clearance mechanisms cannot be excluded. The close relationship between D-dimer and FDP levels suggests that serum FDPs predominantly arise from the interaction of plasmin with crosslinked fibrin rather than with fibrinogen in the conditions in which these were compared.

Fibrinolysis during normal human pregnancy: complex inter-relationships between plasma levels of tissue plasminogen activator and inhibitors and the euglobulin clot lysis time

Although it has been previously considered that blood fibrinolytic capacity is reduced during pregnancy, this has been disputed. Also the mechanisms underlying any change in fibrinolysis in pregnancy require clarification. We have therefore measured the plasma activity of tissue plasminogen activator (t-PA) and inhibitors (t-PAi) and the concentration of the pregnancy specific inhibitor (PA12) antigen, as well as the euglobulin clot lysis time (ECLT) during normal pregnancy. Plasma concentrations of fibrinogen, plasminogen, fibrin(ogen) degradation products (FDP) and cross-linked products (D-dimer) were also monitored. We confirm a marked reduction of the fibrinolytic activity of the plasma euglobulin fraction from the second trimester, and a parallel reduction in t-PA and increase in t-PAi activities, with rapid return to non-pregnant levels post-partum. In contrast, PAI2, whilst undetectable in non-pregnant control plasma, was already measurable in the first trimester, increased through pregnancy, and remained at a high concentration up to at least 48 h post-partum. Fibrinogen and plasminogen concentrations rose progressively through pregnancy and FDP and D-dimer were frequently detectable in late pregnancy plasma. Changes in the ECLT and plasma t-PA and t-PAi activities in pregnancy cannot therefore be directly related to the concentration of PAI2 antigen. Also, despite the apparent marked reduction in fibrinolytic capacity fibrin(ogen) breakdown products are frequently present in increased plasma concentrations in late pregnancy.

Acquired dysfibrinogenaemia masquerading as disseminated intravascular coagulation in acute pancreatitis

Acquired dysfibrinogenaemia as the cause of coagulation abnormalities occurred in a case of acute pancreatitis. Initial coagulation studies showed a prolonged thrombin time and increased concentrations of serum fibrinogen/fibrin degradation products and plasma D-dimer. Further studies on purified fibrinogen showed evidence of degradation of the C-terminal ends of the A-alpha chains, which, it is suggested, resulted from the action of circulating pancreatic proteases. Fibrin polymerisation was thus shown to be impaired, which explains the prolongation of the thrombin time. There was a temporal relation between increased amylase activities and the prolonged thrombin time, both of which returned to normal three weeks after admission. Acquired dysfibrinogenaemia may be an underrecognized phenomenon in acute pancreatitis and may lead to misinterpretation of coagulation test abnormalities.

Association between necropsy evidence of disseminated intravascular coagulation and coagulation variables before death in patients in intensive care units

The necropsy findings in 21 patients on an intensive care unit, on whom coagulation studies had been performed immediately before death, were assessed. Eleven of the patients were retrospectively studied and 10 were reviewed consecutively in a prospective study. Fifteen patients (eight retrospective and seven prospective) had evidence of disseminated intravascular coagulation. Microthrombi were most often found in the lungs and kidneys. The most common abnormal coagulation tests in patients with necropsy evidence of disseminated intravascular coagulation were raised serum concentrations of fibrinogen and fibrin degradation products, prolonged prothrombin time, and reduced platelet counts. Reduced fibrinogen concentrations and a prolonged thrombin time were the least commonly observed abnormalities. There was no difference in either the prevalence or magnitude of abnormality of any particular coagulation variable test result between those patients with evidence of disseminated intravascular coagulation at necropsy and those without.

Peripheral blood lymphocyte subpopulations in patients with primary proliferative and secondary polycythaemia

Peripheral blood lymphocyte subpopulations were measured in 18 patients with primary proliferative polycythaemia and 13 patients with secondary polycythaemia. A decrease in numbers of suppressor T lymphocytes and an increase in the helper:suppressor T lymphocyte ratio was found in those with primary polycythaemia compared with normal subjects and patients with secondary polycythaemia. If other causes of an increased helper:suppressor ratio are excluded this variable may be useful in confirming the myeloproliferative nature of patients with erythrocytosis.