The clinical benefit of blood transfusion: a hypothetical experiment based on a nationwide survey of severe maternal morbidity.

BACKGROUND: It is beyond doubt that blood transfusion services have added to the decline in maternal mortality in high-resource countries. To quantify the clinical benefit of red blood cell (RBC) transfusion in obstetric care, we performed a hypothetical experimental study using data from a prospective nationwide cohort of women giving birth in the Netherlands. STUDY DESIGN AND METHODS: Data were abstracted from a nationwide cohort study on severe maternal morbidity, including obstetric haemorrhage requiring 4 or more units of RBC, to obtain an observed and a hypothetical control group consisting of the same women. In the hypothetical control group, we simulated a situation where RBC transfusion was unavailable and estimated how many of these women would have died in that situation. A questionnaire survey asked experts in major (obstetric) haemorrhage to choose a critical minimal number of RBC transfusions at which a woman with obstetric haemorrhage would have died if RBC transfusion was not available. Maternal mortality rate per 100,000 maternities [maternal mortality ratios (MMR)] and relative risk were calculated for the observed and hypothetical group. RESULTS: The observed MMR was 13 per 100,000 maternities. According to 47 responding experts, the median number of RBC units without which a woman would have most probably died was nine, resulting in a hypothetical MMR of 87 per 100,000 maternities (relative risk 6·5; 95% confidence interval 4·2-10·0). CONCLUSIONS: It can be expected that unavailability of RBC transfusion in obstetric care increases the risk of maternal death 6.5-fold. Blood transfusion thus largely contributes to the decline of MMR and would also be an important pillar of improving quality of care in resource-poor settings.

Allo-exposure status and leucocyte antibody positivity of blood donors show a similar relation with TRALI.

INTRODUCTION: The fraction of transfusion-related acute lung injury (TRALI) cases preventable by deferral of allo-exposed donors has previously been estimated, under the assumption this indirectly estimated the contribution of leucocyte antibodies to the occurrence of TRALI. Our aim was to estimate the fraction preventable by deferral of leucocyte antibody positive donors and to investigate the validity of allo-exposure as a marker for leucocyte antibodies. METHODS: All donors involved in a series of previously published TRALI patients were tested for leucocyte antibodies. The observed number of antibody positive donors was compared to the expected number. From this comparison we estimated the contribution of leucocyte antibodies to the occurrence of TRALI and compared this to the previously reported estimate for allo-exposed donors. RESULTS: Sixty-one TRALI patients were included. Of 288 involved donors 43 were expected and 67 were observed to be leucocyte antibody positive. The observed percentage of positive donors was 8.3% (95% confidence interval (CI): 5.1-11.5%) in excess of the expected. Overall 59% (95% CI: 34-85%) of TRALI cases was estimated to be preventable by the exclusion of all leucocyte antibody positive donors. For plasma-poor products this was 16% (95% CI: -5.0 to 36%). CONCLUSIONS: These estimates were similar to those previously published for allo-exposed donors. This suggests allo-exposure status can effectively be used in donor deferral strategies.

Mortality after transfusions, relation to donor sex.

INTRODUCTION: Blood products from female donors have been associated with worse outcome after blood transfusions. We aimed to quantify the association of overall mortality with transfusions from female blood donors. METHODS: We performed a cohort study of all transfusion recipients during a 5-year period at the Leiden University Medical Center. Analyses were performed in a sub-cohort of recipients with all transfusions from donors of the same sex. Effects in male and female recipients were analysed both separately and averaged, for an overall estimate. RESULTS: Overall, when averaged over both male and female recipients, transfusions from female donors were not associated with increased mortality. However, in male recipients transfusions from female donors were positively associated with mortality, while in female recipients the association was reversed. The hazard ratio for mortality after sex-mismatched transfusions was 1.2 (95% CI, 0.98-1.4). In recipients aged 1-55 it was 1.8 (95% CI, 1.2-2.7). In recipients over 55, with more other risk factors for mortality, it was 1.0 (95% CI, 0.83-1.2). CONCLUSIONS: Overall transfusions from female donors were not associated with increased mortality. However, male recipients of blood from female donors did have an increased risk of death. Female recipients of blood from male donors showed a weaker increase in mortality.

Prevalence of leucocyte antibodies in the Dutch donor population.

INTRODUCTION: Donor leucocyte antibodies have been associated with transfusion-related acute lung injury (TRALI) and can be present in allo-exposed donors. Donor deferral policies aiming at excluding allo-exposed donors are increasingly implemented worldwide. We aimed at assessing the prevalence of leucocyte antibodies in different subgroups of allo-exposed donors in the Dutch donor population. METHODS: Consecutive donors were enrolled during routine whole blood donation. Donors filled out a questionnaire on allo-exposure history. Blood samples were tested for human leucocyte antigens (HLA) (LifeScreen Deluxe and the Lifecodes LSA I/II assays) and granulocyte-reactive (GIFT, GAT, and MAIGA) antibodies. RESULTS: Six thousand and thirty-four consecutive donors (60% men) were included. A total of 2.5% reported a history of blood transfusions, and 51% (of female donors) reported a history of pregnancy. In never allo-exposed donors, the prevalence of granulocyte-reactive antibodies was 2.0% (95% CI: 1.6-2.4), and for HLA antibodies, it was 7.0% (95% CI: 6.3-7.8). In previously pregnant donors, the prevalence of granulocyte-reactive antibodies was increased to 3.0% (95% CI: 2.0-4.0), and for HLA antibodies, it was increased to 33% (95% CI: 30-36). Prevalence of leucocyte antibodies of all types depended on transfusion history, number of pregnancies, time since last pregnancy, and pregnancy outcome. CONCLUSIONS: Fourteen percent of Dutch blood donors are allo-immunized against HLA or granulocyte antigens. Deferral of all self-reported allo-exposed donors will decrease this prevalence to 9%. Deferral of all female donors and transfused male donors will result in a similar prevalence among remaining donors but approximately twice as many deferrals.

Successful treatment with recombinant factor VIIa of therapy-resistant severe bleeding in a patient with acquired von Willebrand disease.

We describe an elderly man who presented with life-threatening hematuria and gastrointestinal bleeding caused by acquired von Willebrand disease associated with monoclonal gammopathy of undetermined significance (MGUS). Standard therapy with desmopressin, von Willebrand factor-containing factor VIII concentrate, tranexamic acid, and immunoglobulin failed to achieve adequate hemostasis. However, treatment with recombinant activated factor VII (rFVIIa) arrested the bleeding completely. Since acquired von Willebrand disease can lead to life-threatening hemorrhage, clinicians should consider rFVIIa as an effective treatment option if standard therapy fails.

[Blind spots of the diagnostic hemostasis screen]. / De blinde vlekken van het oriënterende bloedstollingsonderzoek.

The most powerful instrument to establish the presence or absence of a coagulation disorder is the history of the patient. In addition, screening laboratory tests (consisting of the platelet count, bleeding time and global clotting assays, such as the prothrombin time and the activated partial thromboplastin time) may be helpful to support the diagnosis. In two patients, a 21-year-old man and a 10-year-old girl, with a marked history of enhanced bleeding normal screening laboratory tests were found. The male patient had a congenital alpha 2-antiplasmin deficiency and the girl had a homozygous deficiency of factor XIII. Some defects in the coagulation system (such as defects in fibrin network formation and fibrinolysis, but also mild Von Willebrand disease) are indeed not detected by screening laboratory tests. In patients with a strong suspicion of a coagulation disorder such defects should be specifically tested for.

[Physical diagnosis--percussion and palpation of the spleen]. / Fysische diagnostiek--percussie en palpatie van de milt.

The accuracy of physical examination of the spleen was investigated in the literature. Ultrasonography or scintigraphy was used to test the findings at physical examination. Physical examination has a low sensitivity, but a reasonably good specificity. The interobserver variability is rather high. In general, palpation is more sensitive and specific than percussion. The findings of percussion improve the accuracy of palpation and the combination has a high specificity, of approximately 90%. The two should therefore be used in conjunction. The sensitivity is much lower although it is greatly influenced by the degree of splenic enlargement and the leanness of the patient.

Gene-gene and gene-environment interactions determine risk of thrombosis in families with inherited antithrombin deficiency.

To analyze inherited antithrombin deficiency as a risk factor for venous thromboembolism in various conditions with regard to the presence or absence of additional genetic or acquired risk factors, we compared 48 antithrombin-deficient individuals with 44 nondeficient individuals of 14 selected families with inherited antithrombin deficiency. The incidence of venous thromboembolism for antithrombin deficient individuals was 20 times higher than among nondeficient individuals (1.1% v 0.05% per year). At the age of 50 years, greater than 50% of antithrombin-deficient individuals had experienced thrombosis compared with 5% of nondeficient individuals. Additional genetic risk factors, Factor V Leiden and PT20210A, were found in more than half of these selected families. The effect of exposure to 2 genetic defects was a 5-fold increased incidence (4.6% per year; 95% confidence interval [CI], 1.9% to 11.1%). Acquired risk factors were often present, determining the onset of thrombosis. The incidence among those with exposure to antithrombin deficiency and an acquired risk factor was increased 20-fold (20.3% per year; 95% CI, 12.0% to 34.3%). In conclusion, in these thrombophilia families, the genetic and environmental factors interact to bring about venous thrombosis. Inherited antithrombin deficiency proves to be a prominent risk factor for venous thromboembolism. The increased risks among those with exposure to acquired risk factors should be considered and adequate prophylactic anticoagulant therapy in high-risk situations seems indicated in selected families with inherited antithrombin deficiency.

[Pharmacotherapeutic choices for correction of disorders of primary hemostasis]. / Farmacotherapeutische mogelijkheden voor correctie van stoornissen in de primaire hemostase.

A defective primary haemostatic system is a relatively frequent disorder, due to the increasing use of aspirin and other non-steroid anti-inflammatory agents (NSAIDs) by the general population. Impaired primary haemostasis may result in enhanced perioperative bleeding. Administration of desmopressin is an effective pharmacotherapeutic intervention that will improve the process of primary haemostasis in many cases, with or without additional interventions in the clotting system.

Pharmacological strategies to decrease excessive blood loss in cardiac surgery: a meta-analysis of clinically relevant endpoints.

BACKGROUND: Excessive bleeding may complicate cardiac surgery, and is associated with increased morbidity and mortality. Pharmacological strategies to decrease perioperative bleeding have been investigated in a large number of controlled trials, most of which have shown a decrease in blood loss. However, most studies lacked sufficient power to detect a beneficial effect on clinically more relevant outcomes. We did a meta-analysis of all randomised, controlled trials of the three most frequently used pharmacological strategies to decrease perioperative blood loss (aprotinin, lysine analogues [aminocaproic acid and tranexamic acid], and desmopressin). METHODS: Studies were included if they reported at least one clinically relevant outcome (mortality, rethoracotomy, proportion of patients receiving a transfusion, or perioperative myocardial infarction) in addition to perioperative blood loss. In addition, a separate meta-analysis was done for studies concerning complicated cardiac surgery. FINDINGS: We identified 72 trials (8409 patients) that met the inclusion criteria. Treatment with aprotinin decreased mortality almost two-fold (odds ratio 0.55 [95% CI 0.34-0.90]) compared with placebo. Treatment with aprotinin and with lysine analogues decreased the frequency of surgical re-exploration (0.37 [0.25-0.55], and 0.44 [0.22-0.90], respectively). These two treatments also significantly decreased the proportion of patients receiving any allogeneic blood transfusion. By contrast, the use of desmopressin resulted in a small decrease in perioperative blood loss, but was not associated with a beneficial effect on other clinical outcomes. Aprotinin and lysine analogues did not increase the risk of perioperative myocardial infarction; however, desmopressin was associated with a 2.4-fold increase in the risk of this complication. Studies in patients undergoing complicated cardiac surgery showed similar results. INTERPRETATION: Pharmacological strategies that decrease perioperative blood loss in cardiac surgery, in particular aprotinin and lysine analogues, also decrease mortality, the need for rethoracotomy, and the proportion of patients receiving a blood transfusion.

[Recombinant factor VIIa (eptacog alfa): a new therapeutic option for patients with severe bleeding disorder due to inhibitory antibodies against a coagulation factor]. / Recombinantfactor VIIa (eptacog alfa): nieuwe therapeutische optie bij patiënten met een ernstige bloeding door antistoffen tegen een stollingsfactor.

In 2 patients with severe haemorrhage (a 63-year-old man with haemophilia A (the factor VIII level was 29%) and a 44-year-old woman), of an inhibitory antibody against factor VIII was diagnosed. The development of recombinant factor VIIa (eptacog alpha) has made available a new therapeutic option for patients with an inhibitory antibody against a coagulation factor. Both patients were treated successfully with the new factor after other forms of treatment had failed. The new concept of the coagulation cascade on which the treatment with eptacog alpha is based assumes that the lack of an amplifying loop in the coagulation which takes place via factor IX (in combination with factor VIII) can be compensated by extra stimulation of the principal route (tissue factor-factor VIIa --> factor X) by pharmacological amounts of factor VIIa.

Well-being of haemophilia patients: a model for direct and indirect effects of medical parameters on the physical and psychosocial functioning.

This study outlines the development and evaluation of a structural equation model for establishing the consequences of haemophilia. The hereditary disorder is characterized by a high tendency to haemorrhages, with recurrent bleeding into the joints causing irreversible joint damage. The model is, in general, an attempt to answer the following questions: what is the effect of haemophilia on the well-being (i.e. satisfaction, health, somatic complaints and self-esteem) of patients and what is the additional or mediating role of other individual characteristics in this pathway? Disease severity, joint impairment and disability are defined as antecedents of well-being and the mediating roles of appraisal (i.e. the personal evaluation of the disease), health beliefs (i.e. locus of control), psychological characteristics (i.e. anxiety, anger, depression and optimism) and social support are investigated. Psychological variables turned out to be the strongest determinants of well-being and partly mediated the detrimental effect of disability on well-being. The role of appraisal remained somewhat unclear, as no significant relationship was established between this personal evaluation of haemophilia and well-being. Nevertheless, appraisal very well reflected the level of disability. An internal locus of control and favourable psychological characteristics appeared to reduce the perceived seriousness of haemophilia. No evidence was found for social support to act as a mediator between disability and well-being. The perception of support did show moderately strong associations with psychological characteristics (i.e. anxiety and depression) and satisfaction ratings. The study merits further research on quantifying the relationships between clinical parameters and psychosocial outcomes in patients with a chronic disease.

Partial reconstitution of factor VIII activity from a mild Crm+ hemophilia A patient by replacement of the defective A2 domain.

We further characterised the abnormal factor VIII molecule (factor VIII Leiden) of a Crm+, mild hemophilia A patient with a factor VIII activity of 0.18 IU/ml and a factor VIII antigen of 0.95 IU/ml. Mutation analysis of the coding region, promoter and 3' untranslated region of the factor VIII gene revealed the presence of a C to T substitution at codon 527. This nucleotide change predicts the replacement of an arginine to tryptophan in the A2 domain close to a suggested binding site for factor IXa. Since a previous study of this mutant factor VIII protein suggested that this protein had a reduced affinity for factor IXa, position 527 in the protein might be involved in the interaction with factor IXa. In this study we gathered evidence for our hypothesis that the Arg to Trp mutation at position 527 is the cause of the reduced activity of factor VIII Leiden. Replacement of the mutated A2 domain by wild type A2 domain partially corrected the defect. Factor VIII from normal and factor VIII Leiden plasma was concentrated by cryoprecipitation, activated with thrombin and incubated with excess wild type A2 domain. Competition with excess isolated human A2 domain resulted in a partial reconstitution of the factor VIIa activity of thrombin treated factor VIII Leiden. This supports the hypothesis that the mutation in the A2 domain is the cause of the reduced factor VIII activity.

The role of compliance as a cause of instability in oral anticoagulant therapy.

To assess the role of non-compliance as a cause of instability in patients on oral anticoagulant therapy, a follow-up study of stably and instably anticoagulated patients and of patients beginning oral anticoagulant therapy was performed. Compliance was assessed by pill counting and with the use of pill bottles in the cap of which a microprocessor registered the exact date and time of opening of the bottle. (In)stability of oral anticoagulant therapy was expressed as the number of INRs and as the time spent within the target range and by squared sigma. Subsequently, as a pilot study, a randomized intervention study in instable, non-compliant patients was performed in which these patients were or were not informed about the real nature of the cap of the pill bottle. Nineteen stable and 19 unstable patients and 30 patients beginning therapy were followed for 3 months or less until therapy stopped. Compliance was better in the previously stably anticoagulated patients, although differences were small. Poor compliance was not a major cause of instability in patients starting therapy. Although the pilot intervention study was too small to assess the role of the special pill bottle, it was shown that compliance can be positively affected.

High intensity of oral anticoagulant therapy in patients with cerebral haemorrhage: cause or consequence of the bleeding?

In assessing the optimal intensity of anticoagulant therapy, the International Normalized Ratio (INR) at admission is used as a basis for INR-specific incidence rates. In 47 patients suffering a haemorrhagic stroke we tested the assumption that the INR at admission is an acceptable measure for the INR that preceded the haemorrhage. We found high D-dimer levels in 70% of the patients, which indicated activated coagulation and fibrinolysis. This was not of such an extent that it could also be measured with other routine coagulation tests, with the possible exception of two patients. We found normal INRs in 33 non-anticoagulated patients, and only a mildly prolonged INR of 1.9 in one patient, which was most probably caused by a vitamin K deficiency. We concluded that the INR at admission can be used in studies to assess the optimal level of anticoagulation.

[Revision consensus hemophilia: treatment and responsibility. Nederlandse Vereniging van Hemophilia Patients]. / Herziening consensus hemofilie: behandeling en verantwoordelijkheid. Nederlandse Vereniging van Hemophilia Patienten.

Haemophilia is an X-linked clotting disease occurring in 1400 men in the Netherlands. As the result of factor VIII or IX deficiency, haemophilia patients suffer from severe bleedings, spontaneous or caused by trauma. Bleedings mostly occur in major joints and muscles. Repeated bleedings can cause disability. Treatment of haemophilia consists of replacement therapy with factor VIII or IX. The first aim of treatment is to prevent bleedings (prophylaxis). The second aim is to limit joint damage in case of bleeding by timely and adequate substitution therapy. In addition, physical therapy and sports are used to keep patients in shape. Until the introduction of recombinant factor VIII in 1992 only plasma derived factor VIII and IX products were available. Substitution therapy has caused various side effects, such as allergic reactions. Since the introduction of ultra-pure concentrates, allergic reactions have grown rare. Viral infections like HIV and hepatitis C, which were transmitted through blood products, have not occurred in Dutch haemophilia patients since the introduction of adequate viral inactivation steps. In case of development of antibodies against factor VIII or IX, therapy with factor VIII or IX products is insufficient. Antibody formation is more often seen in haemophilia A (25%) than in haemophilia B (2%). In most cases antibodies disappear during so-called immune tolerance induction. This therapy consists of regular infusion with factor VIII or IX. Once an inhibitor has disappeared, patients can be treated normally once more. As haemophilia is a rare and complex disease patients should be treated in specialized centres, preferably by a comprehensive care team. This is even more justified because treatment of haemophilia is costly. Over the last 20 years haemophilia treatment has improved much. This has resulted in a decrease of the number and of the duration of hospitalization, and a decrease in days lost at school or work. This has led to great improvement of the social life of haemophilia patients.

Increased fetal loss in women with heritable thrombophilia.

BACKGROUND: A successful outcome of pregnancy requires an efficient uteroplacental vascular system. Since this system may be compromised by disorders of haemostasis associated with a prothrombotic state, we postulated that maternal thrombophilia might be a risk factor for fetal loss. We studied the relation between heritable thrombophilic defects and fetal loss in a cohort of women with factor V Leiden or deficiency of antithrombin, protein C, or protein S. METHODS: We studied 1384 women enrolled in the European Prospective Cohort on Thrombophilia (EPCOT). Of 843 women with thrombophilia 571 had 1524 pregnancies; of 541 control women 395 had 1019 pregnancies. The controls were partners of male members of the EPCOT cohort or acquaintances of cases. We analysed the frequencies of miscarriage (fetal loss at or before 28 weeks of gestation) and stillbirth (fetal loss after 28 weeks of gestation) jointly and separately. FINDINGS: The risk of fetal loss was increased in women with thrombophilia (168/571 vs 93/395; odds ratio 1.35 [95% Cl 1.01-1.82]). The odds ratio was higher for stillbirth than for miscarriage (3.6 [1.4-9.4] vs 1.27 [0.94-1.71]). The highest odds ratio for stillbirth was in women with combined defects (14.3 [2.4-86.0]) compared with 5.2 (1.5-18.1) in antithrombin deficiency, 2.3 (0.6-8.3) in protein-C deficiency, 3.3 (1.0-11.3) in protein-S deficiency, and 2.0 (0.5-7.7) with factor V Leiden. The corresponding odds ratios for miscarriage in these subgroups were 0.8 (0.2-3.6), 1.7 (1.0-2.8), 1.4 (0.9-2.2), 1.2 (0.7-1.9), and 0.9 (0.5-1.5). Significantly more pregnancy terminations had been done in women with thrombophilia than in controls (odds ratio 2.9 [1.8-4.8]); this discrepancy was apparent in nine of 11 participating centres and for all thrombophilia subgroups. INTERPRETATION: Women with familial thrombophilia, especially those with combined defects or antithrombin deficiency, have an increased risk of fetal loss, particularly stillbirth. Our findings have important implications for therapy and provide a rationale for clinical trials of thromboprophylaxis for affected women with recurrent fetal loss.