Christopher A. Ludlam

Mortality from liver cancer and liver disease in haemophilic men and boys in UK given blood products contaminated with hepatitis C

BACKGROUND Most people with haemophilia who were treated with blood products before the introduction of virus-inactivation procedures were infected with the hepatitis-C virus (HCV). However, there is little quantitative information about the long-term effects on mortality of such infection. METHODS We carried out a cohort study of mortality from liver cancer and liver disease in 4865 haemophilic men and boys in the UK. They were treated between 1969 and 1985 with blood products carrying a high risk of HCV infection, and were followed up from first recorded exposure to Jan 1, 1993. FINDINGS Based on death-certificate information, mortality was 16.7 times higher than in the general population for liver disease (95% CI 12.5-22.0; 51 deaths), and 5.6 times higher (1.8-13.0; five deaths) for liver cancer. For men and boys with severe haemophilia who were not infected with HIV-1, the cumulative risks of death from chronic or unspecified liver disease or from liver cancer in the 25 years since first recorded exposure to high HCV-risk products were 1.4% (0.7-3.0) at all ages, and 0.10% (0.01-0.7), 2.2% (0.8-6.1), and 14.3% (4.5-40.9) for those with first recorded exposure at ages under 25, 25-44, and 45 or older. For those with haemophilia and HIV-1 infection, the corresponding risks were 6.5% (4.5-9.5) at all ages, and 3.8% (2.1-6.8), 17.1% (10.0-28.5), and 18.7% (6.4-47.6) in the three age-groups. In those with severe haemophilia, age-standardised all-cause mortality was stable during 1969-84 but increased during 1985-92 in both HIV-1-infected and HIV-1-uninfected groups. Among those not infected with HIV-1, the increase in all-cause mortality resulted largely from deaths attributed to chronic or unspecified liver disease or liver cancer in men aged over 45. INTERPRETATION There is an emerging risk of mortality from liver disease and liver cancer in the UK haemophilia population in individuals both infected and uninfected with HIV-1, which probably results from infection with hepatitis C.

Detection of a novel DNA virus (TT virus) in blood donors and blood products

Summary Background A newly discovered DNA virus, transfusion- transmitted virus (TTV), has been implicated as a cause of post-transfusion hepatitis. We investigated the frequency of TTV viraemia in UK blood donors, and the extent to which TTV contaminates blood products such as factor VIII and IX clotting factors. We also investigated the possible aetiological role of TTV in cryptogenic fulminant hepatic failure (FHF). Methods We extracted DNA from plasma of blood donors and patients with FHF, and from blood products (factor VIII and IX clotting-factor concentrates, immunoglobulin preparations). We detected TTV by PCR using primers from a conserved region in the TTV genome. Findings TTV viraemia was detected in 19 (1·9%) of 1000 non-remunerated regular blood donors. Infection occurred more frequently in older donors (mean age 53 years), compared with the age prolife of donors infected with hepatitis C virus and other parenterally-transmitted viruses. TTV contamination was found in ten (56%) of 18 batches of factor VIII and IX concentrate manufactured from such non- remunerated donors, and in seven (44%) of 16 batches of commercially available products. Whereas solvent or detergent treatment had little effect on the detection of TTV in factor VIII and IX by PCR, this virucidal step seemed to inactivate TTV infectivity. TTV infection was detected in four (19%) of 21 patients with FHF; in three cases, infection was detected at the onset of disease and could thus not be excluded from its aetiology. Interpretation TTV viraemia is frequent in the blood-donor population, and transmission of TTV through transfusion of blood components may have occurred extensively. Clinical assessment of infected donors and recipients of blood and blood products, and assessment of TTVs aetiological role in hepatic and extra-hepatic disease, are urgently needed.

Endothelial Dysfunction, Impaired Endogenous Fibrinolysis, and Cigarette Smoking A Mechanism for Arterial Thrombosis and Myocardial Infarction

BACKGROUND Effective endogenous fibrinolysis requires rapid release of tissue plasminogen activator (tPA) from the vascular endothelium. Smoking is a known risk factor for arterial thrombosis and myocardial infarction, and it causes endothelial dysfunction. We therefore examined the effects of cigarette smoking on substance P-induced tPA release in vivo in humans. METHODS AND RESULTS Blood flow and plasma fibrinolytic factors were measured in both forearms of 12 smokers and 12 age- and sex-matched nonsmokers who received unilateral brachial artery infusions of substance P (2 to 8 pmol/min). In both smokers and nonsmokers, substance P caused dose-dependent increases in blood flow and local release of plasma tPA antigen and activity (P<0.001 for all) but had no effect on the local release of plasminogen activator inhibitor type 1. Compared with nonsmokers, increases in forearm blood flow (P=0.03) and release of tPA antigen (P=0.04) and activity (P<0.001) caused by substance P were reduced in smokers. The area under the curve for release of tPA antigen and activity decreased by 51% and 53%, respectively. CONCLUSIONS Cigarette smoking causes marked inhibition of substance P-induced tPA release in vivo in humans. This provides an important mechanism whereby endothelial dysfunction may increase the risk of atherothrombosis through a reduction in the acute fibrinolytic capacity.

Impaired Coronary Tissue Plasminogen Activator Release Is Associated With Coronary Atherosclerosis and Cigarette Smoking Direct Link Between Endothelial Dysfunction and Atherothrombosis

BackgroundThe aim of the study was to establish the influence of proximal coronary artery atheroma and smoking habit on the stimulated release of tissue plasminogen activator (tPA) from the heart. Methods and ResultsAfter diagnostic coronary angiography in 25 patients, the left anterior descending coronary artery (LAD) was instrumented, and the proximal LAD plaque volume was determined by use of intravascular ultrasound (IVUS). Blood flow and fibrinolytic responses to selective LAD infusion of saline, substance P (10 to 40 pmol/min; endothelium-dependent), and sodium nitroprusside (5 to 20 &mgr;g/min; endothelium-independent) were measured by intracoronary IVUS and Doppler, combined with arterial and coronary sinus blood sampling. Mean plaque burden was 5.5±0.8 mm3/mm vessel (range 0.6 to 13.7 mm3/mm vessel). LAD blood flow increased with both substance P and sodium nitroprusside (P <0.001), although coronary sinus plasma tPA antigen and activity concentrations increased only during substance P infusion (P <0.006 for both). There was a strong inverse correlation between the LAD plaque burden and release of active tPA (r =−0.61, P =0.003). Cigarette smoking was associated with impaired coronary release of active tPA (current smokers, 31±23 IU/min; ex-smokers, 50±33 IU/min; nonsmokers 202±73 IU/min;P <0.05). ConclusionsWe found that both the coronary atheromatous plaque burden and smoking habit are associated with a reduced acute local fibrinolytic capacity of the heart. These important findings provide evidence of a direct link between endogenous fibrinolysis, endothelial dysfunction, and atherothrombosis in the coronary circulation and may explain the greater efficacy of thrombolytic therapy for myocardial infarction in cigarette smokers.

Interleukin 6 and Haemostasis

Interleukin 6 (IL-6) is a 26 kDa protein produced by many cell types including activated monocytes and macrophages, endothelial cells, adipose cells and the Th-2 subset of Thelper cells (Aarden et al, 1987; Jirik et al, 1989; MohamedAli et al, 1997; Laharrague et al, 2000). After interaction with a specific saturable receptor, present on a great variety of responsive cells, it promotes a range of activities (Fig 1 and Table I) including antiviral effects (Sehgal & Sagar, 1980), enhancement of proliferation of haemopoietic progenitors (Wong et al, 1988) and induction of acutephase reactant release from hepatocytes (Gauldie et al, 1990) ± a feature shared with other cytokines, collectively known as the IL-6 cytokine family. It is also this last action that leads to the production of C-reactive protein (CRP), a useful surrogate marker of IL-6 (Heinrich et al, 1990). IL-6 may also be involved in the pathogenesis of disease as has been demonstrated in myeloma (Kawano et al, 1988). The subject of this review, however, is the role of IL-6 in haemostasis, which is mediated through a series of differing effects on endothelial cells, leucocytes and hepatocytes with promotion of synthesis of coagulation factors such as fibrinogen, tissue factor and factor VIII (Amrani, 1990; Cermak et al, 1993; Stirling et al, 1998), and also through stimulation of platelet production (Burstein, 1997).

Hepatitis C quantification and sequencing in blood products, haemophiliacs, and drug users

The polymerase chain reaction (PCR) detected specific hepatitis C viral (HCV) RNA sequences in plasma from 15 of 21 haemophiliacs (12 HCV-antibody positive) and 7 of 27 intravenous drug users (13 HCV-antibody positive). Quantification of RNA-positive samples showed high levels of HCV (10(5) to 10(6) copies of RNA/ml) in infected patients. HCV was more frequently found in haemophiliacs infected with human immunodeficiency virus (11/11 HIV-positive and 4/10 HIV-negative patients). HCV-RNA was detected in all batches of commercially available factor VIII tested and in low concentrations in some pools of plasma donations from volunteers. Factor VIII, manufactured from volunteer donations, was uniformly negative by PCR. Phylogenetic analysis of viral sequences showed two distinct groups: one was associated with intravenous drug users and the other with haemophiliacs infected with Scottish factor VIII preparations. Both were distinct from sequences found in commercially available factor VIII.

HLA HAPLOTYPE A1 B8 DR3 AS A RISK FACTOR FOR HIV-RELATED DISEASE

Of 32 patients exposed to a single batch of factor VIII contaminated with human immunodeficiency virus (HIV), 18 became antibody positive. Serial T cell subset analyses over the succeeding four years have shown a progressive decline in circulating T4 cells in those 18 but no change in the 14 who remain seronegative. 2 of the seroconverters have died and a further 7 have symptoms attributable to HIV infection. In the group as a whole, the HLA haplotype A1 B8 DR3 was weakly associated with an increased risk of seroconversion on exposure to the virus while, in those who seroconverted, it was strongly associated with a rapid decline in T4 cells and development of HIV-related symptoms within four years of infection.

Guideline for investigation and management of adults and children presenting with a thrombocytosis.

Guy’s and St Thomas’ NHS Foundation Trust, London, Russells Hall Hospital, Dudley, West Midlands, Arrowe Park Hospital Arrowe Park Road Upton Wirral, Wellcome Trust Sanger Institute, Hinxton, Cambridge, St. James Hospital, James Street, Dublin, Gartnavel General Hospital 21 Shelley Road Glasgow, Addenbrooke’s Hospital, Cambridge, Salisbury Healthcare NHS Trust, Salisbury, Wiltshire, Cambridge Institute for Medical Research, Hills Road, Cambridge, John Radcliffe Hospital, Headley Way, Headington, Oxford, Royal Infirmary, Little France Crescent, Edinburgh, Sandwell and West Birmingham Hospitals, Dudley Road, Birmingham, Royal Hallamshire Hospital, Glossop Road, Sheffield, and Belfast City Hospital, Lisburn Road Belfast, UK

Plasma microparticles and vascular disorders

Microparticles are circulating, phospholipid rich, submicron particles released from the membranes of endothelial cells, platelets, leucocytes and erythrocytes. Investigation into their biological activity has revealed diverse actions in coagulation, cell signalling and cellular interactions. These actions are mediated through their phospholipid rich surfaces and the expression of cell surface molecules which reflect their cell of origin and its state of activation.

Quality‐of‐life differences between prophylactic and on‐demand factor replacement therapy in European haemophilia patients

The European Study on the Clinical Outcomes and Resource Utilization associated with Haemophilia Care was designed to compare various health outcomes associated with on‐demand and prophylactic factor substitution methods in European haemophilia patients. While the primary objective of this research is to conduct an economic analysis, an important component of this study is to evaluate quality‐of‐life differences that may exist between patients who utilize these two styles of therapy. Quality‐of‐life research has emerged as a primary measure of health outcomes because it allows the augmentation of traditional clinical indicators of health with data gathered from the patients perspective. A total of 1033 haemophilia patients from 16 European haemophilia treatment centres were enrolled in this study. The SF‐36, a multidimensional quality‐of‐life instrument, was administered to all participants. This instrument measures eight health‐related quality‐of‐life dimensions: physical functioning, physical role limitations, bodily pain, general health, vitality, social functioning, emotional role limitations, and mental health. All haemophilia subjects enrolled in the study scored significantly lower than the population normative means in the three physical dimensions and in the general health dimension. HIV‐negative haemophiliac subjects differed significantly by factor substitution type in a multivariate analysis examining all eight health dimensions. Univariate analyses testing each dimension separately indicated that patients treated prophylactically reported significantly less bodily pain, better general health, and scored significantly higher in the physical functioning, mental health, and social functioning dimensions. While these results suggest that health‐related quality‐of‐life may be better for haemophilia patients treated prophylactically, future prospective studies that gather periodic quality‐of‐life data over time should be conducted.