Blood coagulation research atKarolinska Institutet 1956-2004PART II - Clinical research

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Blood coagulation research at Karolinska Institutet 1956-2004 PART II - Clinical research

Margareta Blombäck Essäist

Blood coagulation research at Karolinska Institutet 1956-2004 PART II - Clinical research PART II - Basic research: on coronary heart disease, deep venous thrombosis (DVT) and pulmonary embolism (PE); influence of hormones on hemostasis; on hemophilia and Willebrands disease; and on treatment in the above disorders with different drugs. *VTE ( venous thromboembolism includes both DVT and PE)

Coronary heart disease (CHD)

Anders Hamsten In 1978 Anders Hamsten, a young man from the Serafimer University Hospital, stimulated me to start investigating hemostatic variables in a carefully characterised and representative patient group collected by him and consisting of young men who had had a myocardial infarction (MI) before the age of 45 years. Healthy persons recruited from the general population served as controls. Anders later started his own laboratory at the King Gustaf V Research Institute. In the field of hemostasis, three areas in particular have attracted him in relation to the development of MI: the importance of fibrinogen and of activated coagulation factor VII (FVII), and the regulation and clinical significance of the tissue plasminogen activator inhibitor (PAI-1). The patients in Anders Hamstens study had elevated fibrinogen levels and he with collaborators found that 51 percent of the variance in the plasma fibrinogen level was accounted for by genetic heritability. This supported the view that plasma fibrinogen is a primary risk for CHD. Recently Margita Eriksson-Berg, a doctoral student of Karin Schenck Gustafsson at the cardiology unit demonstrated that increased levels of fibrinogen and von Willebrand Factor (VWF) were associated with long-

term risk of CHD and mortality in middleaged women with CHD. Together with Birger Blombäck and his team including a doctorand of mine , Kamaran Fatah-Ardalani, Anders Hamsten showed that the young males with MI (having a quicker thrombin activation) had a slow flow through the fibrin gel formed from their plasma and that a fine-meshed network of thin fibrin fibres was formed, indicating a tight and rigid network thus pointing to the importance of clot formation in CHD. (Ref 1). The same applies to diabetic patients, as shown by Gun JÜrneskog and her collaborators.

Photo by the world-famous Professor Lennart Nilsson of red blood cells surrounded by a fibrin network

A loose fibrin gel network is more easily attacked by degrading enzymes such as plasmin. Paul Hjemdahl has shown that antiplatelet treatment with ASA or clopidogrel (Plavix) reduces some measures of platelet activity at rest as mentioned in part I. Together with his group we have also shown that ASA treatment in very low

doses lead to a very loose network and therefore the combined treatment with these drugs can lead to serious bleedings in connection with different kinds of trauma. A looser network was also demonstrated in patients with diabetes type I if their metabolic control was improved as shown by Jörneskog et al. Anders’ interest in lipids caused him, together with Angela Silveira, to study the activation of coagulation by fat-rich meals and they found an activation of coagulation factors IX and VII but no increase in thrombin generation, which the general concept predicted would occur.

Anders Hamsten and Angela Silvera

However, FVII activation after meals increases the proneness to thrombin production and the formation of occlusive thrombosis in the event of rupture of an atherosclerotic plaque. Later, his group found common variants in the promoter region of the FVII gene affecting the plasma levels of this protein. They suggested that these polymorphisms are likely to be useful markers for resolving the issue of a casual relationship between FVII and the risk of CHD. A thesis about the hemostatic mechanism in patients undergoing bypass surgery was presented by Elisabeth Moor from the cardiology unit. With regard to the fibrinolytic system, many collaborators of Anders Hamsten

and Björn Wiman have contributed to excellent research in this area. In 1985 and 1987 they identified increased plasma levels of PAI-1 as a risk factor for heart infarction, especially for recurrent events. Hamsten et al found that high PAI-1 in MI patients inhibited the activator of the fibrinolytic system (tPA) and correlated with triglyceride levels, indicating that high plasma levels of PAI-1 could be of importance for the pathogenesis of MI. In addition, Björn together with Ulf de Faire’s research group has recently shown that increased levels of tPA/PAI-1 complex as well as of VWF are significant risk markers for recurrent MI. Moreover, Hamsten and collaborators showed that the level of PAI-1 was independently related to reinfarction along with high triglycerides and low HDL cholesterol, impaired cardiac function (poor left ventricular performance) and multiple vessel coronary artery disease, indicating that reduced fibrinolytic activity due to increased PAI-1 levels predisposes to reinfarction in a complex interplay with atherogenic factors, multiple coronary lesions and compromised heart function. Being interested in why PAI-1 is so important for the disease, Hamsten and his collaborator Per Eriksson turned to genetic analyses and showed that the frequency of a polymorphism* (4G instead of 5G) in the PAI-1 gene was higher in the MI patients and that VLDL induces PAI1 in endothelial cells and can explain the link between the two systems. In a study together with researchers at Helsinki University, Hamsten found that PAI-1 concentrations are correlated to liver fat content, at least in patients with lipodystrophy associated with highly active antiretroviral therapy. (Ref 2,3,4).

Venous thromboembolism (VTE) diagnosis and treatment

Venous thromboembolism (VTE) diagnosis and treatment with unfractionated heparin, low molecular heparin*, aspirin

(acetylsalicylic acid), anti-vitamin K drugs (warfarin/coumarin) and a new thrombin inhibitor. * = LMWH or LMMH; M= mass,W=weight

Diagnostic investigations

In a basic study, Hans Johnsson and Ary Ribeiro recently showed that right ventricular load in acute PE is a prognostic marker for death, indicating which patients need intensive treatment with thrombolysis or surgery. (Ref 5).

Kurt Bergström

In the mid Seventies, Kurt Bergström, in addition to developing chromogenic methods together with his pupil Gordon Lahnborg, investigated the effect on hemostasis, especially on antithrombin, of low-dose heparin during surgery. In the late Seventies the coagulationists at the Karolinska Hospital initiated collaboration with hematologists interested in coagulation, led by Dieter Lockner, at the Huddinge Hospital. Dieter and his pupils Sam Schulman, Göran Bratt and Margareta

Holmström, then and later performed beautifully designed cross-over treatment studies in DVT. Besides studying treatment with streptokinase, the team compared treatment with LMMH and unfractionated heparin (UFH, the earlier product), and found a longer half-life and higher bioavailability for LMMH; moreover, if similar doses, measured as heparin (antiXa activity) activity, were given, major bleedings occurred with LMMH. When half the dose of LMMH was given, it still had as good a clinical effect with regard to thrombosis prevention and there were less bleeding complications. Ref 6. Hans Johnsson, the great expert and much in demand at the Karolinska Hospital for treatment of patients with DVT and pulmonary embolism, initiated a multicentre study, together with the Lockner team, which showed that LMMH administered subcutaneously once daily was equivalent to a continuous heparin infusion; this paved the way for out-patient treatment with LMMH, now routine all over Sweden. (Ref 7).

Most of the coagulationists working in the out patient clinic and at the laboratory of the Karolinska Hospital in 2004 and some earlier collaborators. From left til right; Björn Wiman, Margareta Sten-Linder, Margareta Blombäck, Anna Eelde, Katarina Bremme, Hans Johnsson, Jan Svensson, Dieter Lockner, Pia Petrini, Monica Lindstedt, Nils Egberg, Margareta Holmström, Mrs Doris Schulman and Sam Schulman. Missing where Anders Carlsson and Anna Ågren.

Sam Schulman

Sam Schulman transferred his profound knowledge of clinical trials to the Karolinska Hospital, where he worked up to his departure from Sweden in August this year (2004). Sam quickly became well known for his dedicated efforts on hemophilia (see below). He already has a worldwide reputation as the leader of two major multicentre clinical studies. One of them, DURAC (duration of anticoagulation), involved AVK treatment and resolved a number of questions.

Per Lindmarker

Sam and his collaborators, especially Per Lindmarker, showed that recurrence of DVT was lower if treatment was continued for 6 months instead of for 6 weeks after a first event and that still longer treatment reduced the recurrence rate even more.(Ref 8). They also found that recurrence seemed to correlate with high PAI-1 levels and was higher in patients with cardiolipin antibodies and in those homozygous(inherited from both parents) for the Leiden mutation (which occurs in the coagulation Factor V gene); moreover, a DVT was the first sign of cancer in many cases and prolonged AVK treatment probably afforded protection. Hans Johnsson initiated a study on the risk of recurrent DVT in carriers and non-carriers of the Leiden mutation and the G20210A allele in the prothrombin gene. They found that although patients with the homozygous Leiden mutation had an increased risk, recurrence was mainly explained by non-genetic factors. (Ref 9). Together with Björn Wiman, Sam investigated the importance of hypofibrinolysis for the risk of DVT recurrence. While the complete nonapeptide of fibrinopeptide A inhibits thrombin s cleavage of fibrinogen, as mentioned earlier, thrombin activity is inhibited in particular by the tripeptides Phe-Val-Arg and Phe-Pro-Arg (see part I). The above finding soon gave

rise to the idea that such structures could be used as antithrombotic drugs. The Kabi firm, especially Göran Claesson for many years tried to develop thrombin inhibitors. Other groups adopted the idea and have described structures similar to Phe-ProArg. In 1986 Ann-Catrine Teger-Nilsson (see part I-fibrinogen) joined the Hässle group in Mölndal (belonging to Astra) and that group started the development of an oral thrombin inhibitor for use as an antithrombotic drug. Although peptides were excellent inhibitors in vitro, a useful drug also needs to be acceptable in terms such as selectivity, nontoxicity, good oral bioavailability, suitable duration of action and metabolism. After many years, an oral thrombin inhibitor (ximelagatran, Exarta/Exanta) was developed by AstraZeneca. Its structure was related to but very different from the original peptides. In the THRIVE (Thromin Inhibition in Venous Thromboembolism) studies, Sam Schulman and collaborators demonstrated that oral ximelagatran administered twice daily could be used instead of LMMH or warfarin after an acute thrombosis and as secondary prophylaxis after a venous thromboembolism. However, there are still certain sideeffects, such as an increase in liver enzymes, that have to be explained before its introduction in routine especially with regard to long term treatment. Rickard Linder from the cardiology unit defended a thesis on an earlier drug from Astra.

Hormones and coagulation research

Katarina Bremme The coagulation laboratory has been cooperating extensively with the Women Clinic since the early 1980s, both on the influence of different hormones and on the treatment of thrombosis as well as on bleeding problems in women. Margareta Hellgren, who moved to Sahlgrenska University Hospital, Thomas Dahlman and Katarina Bremme, a determined woman with an inquiring mind who has initiated

many valuable studies, have studied the fluctuations in coagulation variables during normal pregnancy showing increased coagulation and decreased fibrinolysis as a protection against bleeding at delivery (Ref 10). They also investigated how to monitor heparin and LMMH treatment in women with acute thrombosis as well as during prophylactic treatment with these drugs during pregnancy and post partum. These investigations are a long-term commitment in that the same woman has to be followed for a considerable time; the frequency of osteoporosis during treatment was also studied. Katarina has assembled many researchers working on different aspects. Thus, Maria Bokarewa, who moved to Gรถteborg early on, investigated women who had had thrombosis during pregnancy and women on oral contraceptives with regard to changes in APC resistance (the response to activated protein C), the wellestablished risk factor for DVT in connection with hereditary thombophilia (Factor V Leiden and a specific prothrombin mutation) and interactions with phospholipid antibodies.

luteal phase (the later part of menstruation) does not seem to have an impact on APC resistance alterations, either during normal menstrual cycle or during ovarian stimulation.

Britt Marie Landgren

Together with Britt Marie Landgren, now at Karolinska University Hospital, Huddinge, Katarina Bremme, Gerd Hall and Ylva Stiernholm, my laboratory published data regarding vaginal treatment with estrogen and progesterone in a higher dosage and found no significant change in any of the hemostatic variables investigated. On the other hand, during oral treatment with a very high (not recommended) dose of estrogen (estradiol), Shu He, Angela Silveira and Katarina Bremme found activated coagulation and depressed fibrinolysis. Thus, an overdose estradiol replacement orally may not be beneficial in preventing CHD after menopause or it may even increase the risk, due to the hypercoagulable state it induces.

Staffan Tรถrngren

Staffan Tรถrngren and collaborators found no improvement when surgical thrombectomy was added to anticoagulant treatment in proximal DVT in pregnancy. Aleksandra Antovic et al demonstrated that a procoagulant state persists in patients with a history of pregnancy-related DVT, even after the symptomatic phase is over; this was confirmed by an imbalance in overall hemostasis, measuring enhanced thrombin generation and depressed fibrinolysis with a method (OHP) recently developed by Shu He et al.( Ref 11,12). Margaretha Wramsby investigated women with habitual abortions and found high frequencies of the Leiden mutation and other hemostatic abnormalities. She also found that estrogen (estradiol) per se or a rapid increase in progesterone during the

Katarina Bremme and Britt Marie Landgren

Martin Ritzen early inspired me (MB) to study the effect of hormones as such. In plasma samples from tall girls who received high doses of estrogens to stop a further increase in height, we found that the main coagulation inhibitor antithrombin decreased significantly and it seemed that the magnitude of the decrease depended on the initial level. In later studies together with Katarina Bremme and Hรฅkan Wramsby on women undergoing IVF

(in vitro fertilization) and in women sampled during the menstrual cycle, we found that, given the levels of the hormone (estrogen or progesterone) in the blood and the hemostatic factor or inhibitor on one occasion, the level of these variables at another level of the hormone or the hemostatic variable could be predicted by measuring only one of the two. Other authors have suggested that estrogen is responsible for the increased VTE risk among pill users. This is now questioned, as epidemiological studies indicate a difference in the risk of VTE between COCs (combined oral contraceptives) with different progestogen contents (so-called second and third generation pills); the higher progestogen content in the latter was thought to have a greater anticoagulant effect but the opposite proved to be the case. In a well-planned crossover study, Marianne van Rooijen et al have compared the two COCs, measuring a hormonebinding protein (SHBG) and hemostatic functions. They found a significant association for both pills between APC resistance and the SHBG. The higher values of both the variables for the third generation pills reflect a higher net estrogenecity (thrombosis tendency).

She He

Together with Liang Deng, Shu He, Rangeen Rafik-Hamad and Eva Ă–stlund, Katarina Bremme has studied hemostatic changes in women with preeclampsia (toxicosis of pregnancy, with high blood pressure and proteinuria) compared with healthy pregnancies. They found that increased levels of fibronectin (a protein produced by endothelial cells) and von Willebrand factor are warning signs of preeclampsia and that PAI-1 is increased and coupled to increased resistance in the placenta. The level of PAI-2, produced in the placenta only, is increased in the mother and is correlated both to the weight and function of the placenta and to the intrauterine growth

of the child. Katarina Bremme, together with Shu He and collaborators, studied women four years after preeclamsia and found a persistent endothelial dysfunction, measured as disregulation of blood pressure, hemostatic perturbation and dyslipoproteinemia, indicating a proneness to future CHD. In a new study in women one year after preeclampsia, Rangeen Rafik-Hamad has confirmed the endothelial dysfunction by measuring endothelium dilatation through ultrasound examination of the brachial artery.

PO Hedlund - Peter Henriksson

It is not only in women that the effect on hormones has been investigated. In the late Eighties, PO Hedlund at the Karolinska Hospital and collaborators investigated prostate cancer patients treated with oestrogens, estramustine phosphate or orchidectomy, respectively, and found that 6/20 patients treated with the drugs developed cardiovascular complications. This was reflected in significant shifts in the levels of many hemostatic variables towards hypercoagulation in those treated with the drugs. The increase in coagulation FVII, for example, was new to us. Peter Henriksson et al. at the Huddinge Hospital reached the same conclusion in a similar study comparing oestrogen treatment and orchidectomy. In 1990 they investigated the influence of non-oral injections of polyestradiol phosphate and found much less activation of coagulation (no increase in FVII). In these patients and in those with orchidectomy reported above, no cardiovascular complications were observed.

Hemophilia A and von Willebrand´s disease (VWD) About a month after fraction I-0 had been shown to be life-saving in a girl with pseudohemophilia, later identified as von

Willebrand s disease (see Part I), administration of this fraction to a boy with hemophilia A gave the same good result - an increased level of FVIII and arrest of severe joint bleeding. This meant that a method had been introduced whereby patients with hemophilia A or VWD could have adequate treatment and, indeed throughout the world. Fraction I-0 was produced at Karolinska Institutet for almost a decade (for many years in a cellar, alongside the production of other items from intestines, for in-

and Australia, especially during the Sixties, and probably for even longer in developing countries as the procedure was rather simple. (Ref 13). Together with Inga Marie Nilsson, the heredity of several Swedish families with ”pseudohemophilia” as described above was investigated. We travelled around southern Sweden, drawing samples from patients and their relatives. We had indeed lots of fun and adventures during those trips. Erik Jorpes became very interested in this research and initiated a trip to the Åland islands, where we demonstrated that the patients of the original bleeder-family, described by Dr Erik Von Willebrand, had the same disorder, now called Von Willebrand s Disease (VWD). There were, however, several other bleeder families on the Åland islands and in further investigations my collaborators (especially Dag Nyman) and I showed that not all of them had the genuine VWD. Many stories can be told about those trips. (Ref 14).

Zhiping Zhang and Maria Anvret

Birger Blombäck holds a bottle of fraction, I-O, the first concentrate produced to be used for hemophiliacs, 1956.

stance), after which its manufacture was taken over by Kabi - later incorporated into Pharmacia and still later into PharmaciaUpjohn. In Sweden, fraction I-0 was used for treatment of VWD until the end of the Eighties, while more purified factor concentrates from plasma (starting in the midto-late Sixties) and later recombinant products were developed for hemophilia A. Fraction I-0 was also produced in several other countries, such as France, Canada

In the early Nineties, Zhiping Zhang, Maria Anvret and collaborators at KI investigated twenty-five families with VWD belonging to the Stockholm Hemophilia Centre and the surviving members of the original Åland family. We could then finally confirm what we had always suspected, namely that the very sick patients with VWD (so-called type 3) were either homozygous ( same genetic VWF defect from each parent). or double heterozygous (different genetic VWF defect from each parent) for the disease. Thus, there was always a mutation in both of the sick child s parents. These studies were maybe the most enjoyable I ever made. (Ref 15)

Photo of the original family described by Von Willebrand, a Helsinki doctor, and of the mutations we found in the surviving members.

Photo of the original family described by Von Willebrand, a Helsinki doctor, and of the mutations we found in the surviving members. The family lived on Fรถglรถ, an island in the ร land archipelago. The bleeding history and the difficulties they met are described in Ref 14. The history presented there was controlled by the sister of the proband in 1999. From the Sixties to the Eighties, several theses were published from KI on epidemiology, carriers and treatment of hemophilia and on VWD (three were in collaboration with Inga Marie Nilsson in Malmรถ: i.e. by Olof Ramgren, Anders Larsson and Jรถrgen Silwer). One very interesting thesis, by Thomas Wahlberg, attacked the diagnostic problems in new ways. Some papers from my laboratory on genetic studies in hemophilia A and B were published

together with Claes Wadelius, Uppsala University. Nils Egberg in 1976 purified the immunoglobulin (IgG) responsible for the inhibitory effect in the first reported patient with severe von Willebrand s disease who had developed an inhibitor to the VWF. As mentioned above, hemophilia A patients could be treated with fraction I-0, which was produced for a decade in KI and later at Kabi. Soon other companies prepared more purified fractions and for the hemophiliacs the introduction of home treatment (i.e. the fraction was injected by the patient or a relative) was a revolution because, for instance, patients no longer had to miss days at work or in school or the possibility of travel. Unfortunately, the importance of using plasma from Sweden and Finland was not understood; in1979, 82 % of the factor concentrates were pre-

pared in the USA and other countries. It was known that coagulation factor concentrates were liable to be contaminated with hepatitis virus and a German firm had introduced a procedure for inactivating hepatitis (but these concentrates were not used in Sweden). In 1979, urged on by a WHO recommendation that every country in the Western World must be selfsufficient, the Swedish National Board for Technical Development promoted a project for obtaining more plasma in Sweden.

about hemophilia patients with HIV and/or with hepatitis C. Sam Schulman has done a great deal of research in this field and is also known for his commitment to the International Hemophilia Organisation. With regard to treatment, Sam together with Hans Johnsson and Ulla Hedner was the first to use recombinant FVIIa, now known for its effect in the treatment of bleedings in hemophiliac patients with inhibitors, as well as in other disorders (recently also to stop stroke caused by hemorrhage).

The possibility of blood products being contaminated with HIV was first discussed in 1982 and in 1983 it was found that many Swedish hemophiliacs were affec-

Sam and collaborators have also shown that in patients with a congenital bleeding disorder, eradication therapy for infection with Helicobacter Pylori leads to less gastrointestinal hemorrhages. In 1956-57, when Inga Marie and I met our first patients with hemophilia, the mean age of severely ill patients with hemophilia A and B was 16 years and those who lived longer were mostly crippled by painful joint bleedings. In 1958 we therefore initiated prophylactic treatment by administering fraction I-0 at regular intervals in boys with severe hemophilia to protect them from joint bleedings. This has led to that Swedish patients with hemophilia and von Willebrand’s disease are not crippled at all; i.e. if treatment was initiated early, and that they can participate in several sport activities. Thanks to major efforts, especially by Inga Marie Nilsson, such treatment is now used in most countries in the Western World.

Hemophiliacs who receive modern prophylactic treatment can partipate in almost all sports or work.

ted (presented at the International Congress of Hemophilia in Stockholm). Later it turned out that they had been affected already between 1979 and 1981. Many papers have been published from the Hemophilia Centre at the Karolinska Hospital

In the Seventies and up to 1985, the adult out-patients with hemophilia A, hemophilia B and von Willebrand s disease were also treated and cared for not only in daily life but also on trips to the Canary Islands by Dr Barbro Wiechel, Stockholm Blood Centre. She published several reports about the effect of home treatment and about the frequency of hepatitis in this cohort.

Pia Petrini - Måns Edlund

Pia Petrini, a much-loved doctor who together with her excellent nurse built up an outstanding centre for children with hemophilia and thrombosis, has devoted her research to preventing disablement from joint bleedings and has a world-wide reputation for this work. She has shown that in order to avoid joint damage and its pro-

against bleeding after teeth extraction in patients with hemophilia and on treatment with anti-vitamin K drugs.

Other research Leukemia research

Christer Paul, who has been working together with Dieter Lockner, focuses on leukemia and hemostatic aspects; an interesting thesis on this subject was presented by Eva Törnebohm, whose tutor from the laboratory was Nils Egberg.

Treatment with dextran, desmopressin and snake venom enzyme

A painting by Ivar Arosenius, one of Sweden’s best-know artists in the early 20th century. Arosenius suffered from hemophilia A and represented the horror and fear of bleeding to death in many paintings, including those for fairy tales (still familiar to many Swedish children) for his little daughter Lillan.

gression, prophylactic treatment with factor concentrates has to start at the age of 12 years and that the mean age for introducing the treatment at home is 2½ years. Furthermore, she demonstrated that the lowest effective level of the coagulation factor in a child must be determined individually. Ref 16. Måns Edlund from the Women Clinic has focused on the importance of considering the high frequency of VWD and platelet disorders as a cause of menorrhagia and how to treat with tranexamic acid and desmopressin in order to avoid unnecessary uterus extirpation. Tranexamic acid administered orally or locally in the mouth was shown by Göran Ramström et al to be of great help in protecting

Jan Svensson has studied the effects of dextran and desmopressin on coagulation and fibrinolysis, both in healthy controls and in patients undergoing total hip replacement. This treatment regime reduces blood loss by improving platelet function/ increasing the FVIII/VWF complex level and lowering the risk of thromboembolism by decreasing PAI-1 and increasing t-PA levels, also preventing critically low levels of antithrombin. Nils Egberg illustrated the possible use of defibrination by means of Defibrase, which contains snake venom enzymes, especially Bothrox atrox, to treat thrombotic events and even to prevent thrombotic complications in connection with vascular surgery. Defibrase treatment seems only to affect (decrease) the fibrinogen concentration, leaving other parts of the hemostatic system intact. A secondary increase in fibrinolytic activity eliminates the fibrin clots formed by the action of Defibrase.

Blood products

In addition to the research mentioned above, from time to time my laboratory work has focused on how to prepare better plasma for use in intensive care and for industrial production of coagulation factors. Some of this research was done together with Joanna Chmielewska and Göte Carlebjörk. The ongoing research,

performed by Anna-Maija Suontaka in collaboration with the Blood Centre (Tommy Sรถderstrรถm), is devoted to studying how storage of plasma affects the hemostasis, kallikrein and complement systems.

Work with the intensive care unit

The coagulation laboratory has always collaborated successfully with the intensive care unit at Karolinska Hospital. In a very important thesis on multitrauma patients, Sixten Bredbacka elucidated the significance of changes in the coagulation, fibrinolysis and elastase systems for organ failure and clinical outcome.

Hemostasis and inflammation

A young pupil of mine, Johanna S Ungerstedt, has presented very interesting findings with regard to the B vitamin derivative nicotinamide and endotoxin, findings possibly useful for intensive care treatment. Together with Andreia Bunesco, Nils Egberg demonstrated the parallel reactions in the hemostatic and immune systems, illustrated by the long-standing formation of platelet-leucocyte complexes after major surgical intervention.

Ongoing and future Hemostasis Research at Karolinska Institutet

Atherothrombotic disorders-interplay between hemostasis, vessel wall and inflammation: The hemostasis researchers have recently been attracted by the link between blood coagulation and defence mechanisms such as the inflammation and immune systems. More and more research will be centred on the interactions between the vessel wall, its components, aspects of inflammation and hemostasis. Several groups are presently working on such projects, for example the groups led by Jan Andersson, Jan Palmblad, Paul Hjemdahl and Jesper Swedenborg-Ulf Hedin. The

group led by Jan Andersson will hopefully solve the hemostasis problems in sepsis.

The basic and genetic hemostasis research

The basic and genetic hemostasis research to uncover the mechanism behind coronary heart disease and stroke will be continued at the GV Research Institute (Anders Hamsten) and at Danderyd Hospital by the stroke and diabetic researchers. New epidemiological studies of cardiovascular disorders will be presented by Ulf de Faire and Bjรถrn Wiman. Karin Schenck-Gustafsson will focus on women and cardiovascular disorders. In this respect the importance of investigating fibrin gel formation and structure in plasma (reflecting the end point of coagulation) and of demonstrating in clinical studies both a tighter fibrin network in cardiovascular disorders and a looser network during treatment with anticoagulants, must be considered. The increased levels of VWF in disorders such as chronic heart disease, stroke and thromboembolic disorders are coming more and more into focus as a marker for the degree of vessel damage. The increase may have to do with the inflammatory process. The importance of high Factor VIII levels has also attracted attention. Another factor that might be of interest is the von Willebrand Factor degrading enzyme ADAMTS 13.

Treatment aspects in thrombotic venous and arterial disorders Several studies will continue at the blood coagulation unit together with the coagulation laboratory of the Karolinska University Hospital, Solna, in collaboration with the other university clinics in Stockholm.

Treatment studies with new thrombin nonoral and oral inhibitors (including ximela-

gatran) that prevent thromboembolic disorders, both venous and arterial, including heart infarction and stroke, will continue. In the long run these drugs, which most probably need less monitoring and hopefully give less bleeding complications, may replace oral anti-vitamin-K (warfarin/coumarin) as well as heparin and LMM heparin. Other studies will hopefully be made on bleeding problems with newly introduced drugs. At present, more and more patients who come to the hospital for surgery are on treatment with antiplatelet drugs (clopidogrel, aspirin), etc. Life-threatening bleedings can occur. Platelet transfusions are often deleterious or do not help much and patients who survive may spend many days in the costly intensive care unit. Recombinant FVIIa seems to be an alternative; its ability to stop bleeding immediately makes it cost effective. But more studies are needed. Paul Hjemdahl and his group will study hemostasis alterations during treatment with platelet inhibitors, lipid and hypertension lowering drugs.

The influence on hemostasis

The influence on hemostasis of hormones, contraceptives and hormonal replacement therapy (HRT) after menopause will be focused by Katarina Bremme s research group at the Women Clinic of the Karolinska University Hospital.

Hemophilia and von Willebrand s disease; gene therapy Studies on genetic and biochemical disease modulators in hemophilia A, hemophilia B and von Willebrand s disease will be made to understand why some patients seem to be less affected than others in spite of having the same factor concentration in their blood.

Genetic and epidemiologic studies on patients with von Willebrand s disease will

hopefully be continued by Pia Petrini, Margareta Holmström and co-workers in collaboration with doctors (Margareta Sten-Linder and others) at the Coagulation Laboratory of the Karolinska University Hospital in Solna, as the Stockholm Hemophilia Centre has the Western world s largest cohort of patients with severe forms of this disease, as well as the largest cohort of hemophilia A patients in Sweden. Edvard Smith and his research group at Karolinska University Hospital Huddinge have developed a non-viral gene transfer method called Bioplex. By designing plasmids, or oligonucleotides, to contain the corresponding target sequence for a specific anchor molecule, complexes with desired biological functions can easily be generated. The long term aim is to combine different functional entities in order to achieve optimal, synergistic interactions, allowing enhanced gene transfer in vivo. In the future this method will hopefully be used to perform gene therapy in hemophilia A, a disease in which a small increase in the level of FVIII has a significant clinical effect. As a rule, a level similar to that found in mild hemophilia does not give either minor bleedings or spontaneous joint bleedings and confers better protection during trauma. (Ref 17).


Most of the references are selected by the authors themselves 1. Fatah K, Hamsten A, Blombäck B, Blombäck M: Fibrin gel network characteristics and coronary heart disease: Relations to fibrinogen concentration, acute phase protein, serum lipoproteins and coronary atherosclerosis: Thromb Haemostas 68:130-5, 1992. 2. Hamsten A, Wiman B, de Faire U, Blombäck M. Increased plasma levels of a rapid inhibitor of tissue plasminogen activator in young survivors of myocardial infarction. New England Journal of Medicine 1985;313:1557-

63. 3. Hamsten A, de Faire U, Walldius G, Dahlén G, Szamosi A, Landou C, Blombäck M, Wiman B. Plasminogen activator inhibitor in plasma: risk factor for recurrent myocardial infarction. Lancet 1987;ii:3-9. 4. Wiman B, Andersson T, Hallqvist J, Reuterwall C, Ahlbom A and de Faire U. Plasma levels of tissue plasminogen activator/plasminogen activator inhibitor-1 complex and von Willebrand factor are significant risk markers for recurrent myocardial infarction in the Stockholm Heart Epidemiology Program (SHEEP) study. Arterioscler Thromb Vasc Biol 2000; 20: 2019 23. 5. Ribeiro A,Lindmarker P, Johnsson H, Juhlin-Dannfelt A, Jorfelt L. Pulmonary embolism. One year follow-up with echocardiography_doppler and five year survival analysis. Circulation 1999; 99:1326-30. 6. Bratt G, Törnebohm E. Lockner D, Bergström K A human pharmacological study comparing conventional heparin and low molecular weight heparin fragment. Thromb Haemost 1985; 53:208-11. 7. Lindmarker P,Holmström M,Granqvist S,Lockner D,Johnsson H. Comparison of once-daily subcutaneous Fragmin with continuous unfractionated heparin in the treatment of deep venous thrombosis. Thromb Haemost 1994;72:186-90. 8. Schulman S, Rhedin A-S, Lindmarker P, Carlsson A, Lärfars G, Nicol P, Loogna E, Svensson E, Ljungberg B, Walter H, Viering S, Nordlander S, Leijd B, Jönsson K-Å, Hjorth M, Linder O, Boberg J and The DURAC Trial Study Group. A comparison of six weeks with six months of oral anticoagulant therapy after a first episode of venous thromboembolism. N Engl J Med 1995; 332: 1661-5. 9. Lindmarker P, Schulman S, Sten-Linder M, Wiman B, Egberg N, Johnsson H, The risk of recurrent venous thromboembolism in carriers and non-carriers of the G1691 A allele in the coagulation factor V gene and the G20210A allele in the prothrombin gene. Thromb.Haemost 1999;81:684-9.

10. Bremme K,Östlund E,Almqvist I,Heinonen K,Blombäck M.Enhanced thrombin generation and fibrinolytic activity in normal pregnancy and puerperium. Obst Gyn 1992; 80:132-7, 11. Antovic A,Blombäck M,Bremme K,van Rooijen M,He S.Increased hemostasis potential persists in women with previous thromboembolism with or without APC resistance. J Thromb Haemost 2003;1:2531-5, 12. He S, Antovic A, Blombäck M. A simple and rapid laboratory method for determination of haemostasis potential in plasma. II. Modifications for use in routine laboratories and research work. Thromb Res 2001; 103:355-61. 13. Blombäck M. A human factor VIII concentrate (Fraction I-0). Handbook of Hemophilia. Eds Brinkhous M, Hemker H.C. Chapter 33. Excerpta Medica. Amsterdam 1975: p 493512. 14. Blombäck, M. Scientific visits to the Åland Islands. Haemophilia ,1999; 5, Suppl 2: 1218.(describes 3 scentific excursions to the Åland Islands). 15. Zhang Z, Lindstedt M, Blombäck M, Anvret M. Effects of the mutant von Willebrand factor gene in von Willebrand disease. Hum Genet 1995;96: 388-94. 16. Petrini P. Treatment strategies in children with hemophilia. Paediatr Drugs 2002; 4:42737. 17. Svahn MG, Lundin KE, Ge R, Törnquist E, Simonson EO, Oscarsson S, Leijon M, Branden LJ, Smith CIE. Adding functional entities to plasmids. J Gene Med 2004; 6:S36S44.

Margareta Blombäck, Essäist Margareta Blombäck - professor emerita - one of the leading figures wihin the Swedish research on Blood coagulation 1956 - 2004. Together with her husband, Birger Blombäck, she has reached international fame. Here you will find a summary of the Swedish reseach in this field.

Read Margareta Blombäck’s essay Blood coagulation research at Karolinska Institutet 1920-2004 PART I - Basic research

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