Diagnosis of deep vein thrombosis by the use of a rapid ELISA D-dimer test, CUS, and a clinical model: a cost-effectiveness analysis.
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Clinical Laboratory Techniques↗
Biomedical subjects
J J Michiels
Publications and source records attributed to J J Michiels.
Phenotype variability of the dominant beta-thalassemia induced in four Dutch families by the rare cd121 (G-->T) mutation.
Eight patients who were carriers of beta-thalassemia induced by the cd121 (G-->T) mutation are described in four nonrelated Dutch families. This mutant, which is considered rare and inherited in a dominant manner, is expressed in a different way among each of the four families and even among carriers of the same family. The symptoms vary from an hemolytic anemia of intermediate gravity with hepatosplenomegaly, inclusion bodies and erythroblastosis, to a mild anemia with minor hematological abnormalities. We report the analytical procedures used for the detection of the mutant, the hematological and clinical data of the four families and discuss the variable physiopathology of this molecular defect. We also compare the variation in fetal hemoglobin expression in relation to the haplotypes of the beta-gene cluster and to the different hematological conditions. The presence of this rare mutant in four nonrelated Dutch families could derive from a single mutation or from multiple events. The existence of the four mutations in three different haplotypes suggests the occurrence of at least two independent events. The presence of five abnormal hemoglobins and the beta-thalassemia defect on different haplotypes at cd121 also suggests a relatively increased rate of mutations at this particular site.
Adult↗
Acquired von Willebrand disease.
Acquired von Willebrand disease (AvWD) is an acquired bleeding disorder which may suddenly become manifest in individuals, usually in the absence of a personal or family history of bleedings and frequently in association with monoclonal gammopathies, lymphoproliferative, myeloproliferative and autoimmune disorders. In a minority of the cases AvWD may develop in association with drugs or solid tumours. Pathogenetic mechanisms involve autoantibodies directed against von Willebrand factor (vWF) resulting in a rapid clearance of vWF from the circulation and/or inactivation of plasma vWF; absorption or adsorption of plasma vWF to malignant cells; drug-induced or cell-mediated proteolysis of plasma vWF; acquired decrease in synthesis of vWF and/or release of vWF from storage sites; or precipitation of plasma vWF. Treatment options include--whenever possible--treatment of the underlying disorder or symptomatic treatment aimed at replacing the loss of vWF by either infusion of vWF-rich concentrates or administration of desmopressin (DDAVP). In selected cases with anti-vWF antibodies, administration of high-dose intravenous gammaglobulin, plasma exchange or extracorporeal immunoadsorption may be successful.
Child↗
Laboratory diagnosis of hereditary thrombophilia.
Genetic defects of antithrombin (AT) or one of the components of the protein C pathway are associated with hereditary thrombophilia. Laboratory assays are currently available to diagnose and type hereditary thrombophilia due to deficiency or dysfunction of one of the anticoagulant factors antithrombin (AT), protein C (PC) and protein S (PS), and APC resistance without the need of DNA analysis. There are no functional tests for the prothrombin mutant G20210A and thrombomodulin mutations, which can be diagnosed by a PCR-based test or by gene analysis, respectively. Hereditary AT deficiency is classified in a quantitative type I and three functional type II deficiencies affecting the reactive site (RS), heparin binding site (HBS), or pleiomorphic site of the AT protein. All four types of hereditary AT deficiencies can be diagnosed by a heparin cofactor assay and one immune assay in combination with crossed immunoelectrophoresis of the AT protein. The combination of an enzyme-linked immunoadsorbent assay (ELISA) and a functional Protac-APTT-based assay for PC will detect quantitative type I and dysfunctional type II PC deficiencies. There is a significant overlap in PC antigen and functional levels between heterozygotes of PC deficiency and normals leaving a gray zone of uncertainty in differentiating congenital PC deficiency and normal individuals. Accurate diagnosis of hereditary PS deficiency should be a combination of tests aimed to measure free PS activity and antigen and total PS antigen levels. APTT-, Xa-, and RVVT-based APC-resistance tests, when test plasmas are diluted in factor V deficient plasma, have increased in sensitivity and specificity to 100% for the discrimination of normal individuals from heterozygotes and homozygotes for factor V Leiden. The RVVT-based APC-resistance test provides better separation of factor V Leiden and normals in the various clinical settings, lupus anticoagulant in particular. The modified APC-resistance tests also claim a separation between heterozygotes and homozygotes for factor V Leiden in the normal population, asymptomatic subjects, and thrombosis patients. Below a certain cut-off level, a minor overlap of normalized APC ratios between heterozygotes and homozygotes for factor V Leiden of thrombosis patients has been shown in one study, which still points to the need to perform the more time consuming and expensive DNA test to identify heterozygotes from the more clinically significant homozygotes. The prothrombin-based APC-resistance test, which measures thrombin activated factor Va in highly diluted test plasma, appears to be the most sensitive and specific of all APC-resistance tests and separates normal individuals from heterozygotes and heterozygotes from homozygotes for factor V Leiden without the need of confirmation by a DNA test.
Activated Protein C Resistance↗
Rational diagnosis of deep vein thrombosis (RADIA DVT) in symptomatic outpatients with suspected DVT: simplification and improvement of decision rule analysis for the exclusion and diagnosis of DVT by the combined use of a simple clinical model, a rapid sensitive D-dimer test and compression ultrasonography (CUS).
The diagnosis of deep vein thrombosis (DVT) in outpatients is difficult to establish. The classical clinical signs of DVT are unspecific and found in several other conditions besides DVT. Therefore, these patients are subjected to elaborate, expensive invasive or noninvasive procedures that actually confirm DVT in only 20-30% of patients in this setting. A prospective management decision study, based on a pretest clinical probability (PCP) estimation, compression ultrasonography (CUS), and a rapid enzyme-linked immunoadsorbent assay (ELISA) D-dimer test, is proposed. The PCP model of Wells allows for reasonably accurate classification of patients into low, moderate and high probability for suffering DVT. Combined with CUS, high predictability is achieved. The D-dimer assays presently available can be rapidly performed and are accurate to a high degree, especially in ruling out DVT. It is proposed to establish a "Rational Diagnosis of Deep Vein Thrombosis (RADIA DVT)" model to be tested in a large number of patients with suspected DVT. This model would be less expensive to perform and likely yield a highly accurate diagnosis on the basis of which anticoagulant therapy could be initiated or withheld.
Ambulatory Care↗
The place of D-dimer testing in an integrated approach of patients suspected of pulmonary embolism.
When a patient is suspected of having pulmonary embolism (PE), the first procedure performed in most institutions is lung scintigraphy. Here we propose an alternative diagnostic strategy based on the following sequential combination of procedures: clinical assessment, D-dimer measurement, ultrasonography of lower limbs, and lung scan. This integrated approach may rule out PE in the majority of outpatients suspected of PE and permits district hospitals without lung-scan facilities to manage approximately 50% of outpatients without referral. D-dimer alone will exclude PE in about 30% of patients at low cost. This stepwise strategy is especially useful because only 20-35% of patients suspected of PE really have the disease. Thus, in the majority of patients, ruling out the disease has replaced ruling in the disease.
Algorithms↗
Rational diagnosis of pulmonary embolism (RADIA PE) in symptomatic outpatients with suspected PE: an improved strategy to exclude or diagnose venous thromboembolism by the sequential use of a clinical model, rapid ELISA D-dimer test, perfusion lung scan, ultrasonography, spiral CT, and pulmonary angiography.
A prospective management decision analysis for the exclusion and diagnosis of pulmonary embolism (PE) based on pre-test clinical probability (PCP) estimation for PE, a rapid ELISA D-dimer test, perfusion lungscan (P-scan), CUS, spiral CT, and pulmonary angiography is proposed. The modified PCP model for PE of Wells et al. allows reasonably accurate classification of patients with no, low, moderate, and high probability for PE. The combined rational use of the evidence-based noninvasive imaging techniques P-scan, CUS, and spiral CT with the rapid ELISA D-dimer test and PCP will reduce the need for invasive pulmonary angiography to perhaps 10 to 15% of patients, who initially presented with suspected PE. A Rational Diagnosis of Pulmonary Embolism (RADIA PE) model is proposed for testing in a large multicenter study of patients with suspected PE.
Ambulatory Care↗
Essential thrombocythaemia is not associated with postpartum thrombosis or an increased risk of venous thromboembolism. Thrombocythemia Vera Study Group and European Working Group on Myeloproliferative Disorders.
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Female↗
[Radioactive phosphorus (32P); an old, but not bad treatment in polycythemia vera].
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Bloodletting↗
Diagnostic criteria of the myeloproliferative disorders (MPD): essential thrombocythaemia, polycythaemia vera and chronic megakaryocytic granulocytic metaplasia.
Philadelphia chromosome-positive essential thrombocythaemia (Ph(+)-ET) and chronic granulocytic leukaemia (Ph(+)-CGL) constitute a separate malignant disease entity, whereas essential thrombocythaemia (ET), polycythaemia vera (PV) and chronic megakaryocytic granulocytic metaplasia (CMGM) belong to the Philadelphia chromosome-negative (Ph-) myeloproliferative disorders. The megakaryocytes in Ph(+)-ET and Ph(+)-CGL are abnormal and small with round nuclei, showing little lobulation. Both the number and size of megakaryocytes in Ph-ET, -PV and -CMGM are typically increased. Enlarged megakaryocytes with mature cytoplasm and multilobulated nuclei and their tendency to cluster in a normal or slightly increased cellular bone marrow represent the hallmark of ET. In reactive thrombocytosis the size and morphology of increased megakaryocytes are normal. The characteristic increase and clustering of enlarged mature and pleomorphic megakaryocytes with multilobulated nuclei and proliferation of erythropoiesis in a moderate to marked hypercellular bone marrow with hyperplasia of dilated sinuses is the diagnostic hallmark of untreated PV. In secondary polycythaemia, in which increased cellularity of the erythroid cell line may be present, the number, size and morphology of megakaryocytes remain small and normal. CMGM, including early stages without myelofibrosis and advanced myelofibrotic stages of agnogenic myeloid metaplasia, appears to be a distinct neoplastic proliferation of neutrophilic granulopoiesis and megakaryopoiesis. The histopathology of the bone marrow in CMGM is dominated by atypical, enlarged and immature megakaryocytes with cloud-like nuclei which are not seen in ET and PV. Myelofibrosis in ET, PV and CMGM is graded in no reticulin fibrosis (MFO), early reticulin fibrosis (MF1), advanced reticulin sclerosis with minor collagen fibrosis (MF2) and advanced collagen fibrosis with or without osteosclerosis (MF3). Myelofibrosis is not a feature of ET, may occur in PV, and constitutes a prominent feature of CMGM during the natural history of the disease.
Bone Marrow↗
Decreased half-life time of plasma von Willebrand factor collagen binding activity in essential thrombocythaemia: normalization after cytoreduction of the increased platelet count.
Patients with essential thrombocythaemia (ET) exhibit a decrease of large von Willebrand factor (VWF) multimers in plasma, which is inversely related to the platelet count. In the present study we investigated whether the decrease of large VWF multimers in plasma with increasing platelet counts is the consequence of increased turnover of large VWF multimers in vivo. To that end we measured the half-life times of endogenously released VWF:Ag and VWF:CBA (collagen binding activity) after intravenous administration of desmopressin (DDAVP) to nine ET patients and nine control subjects (N). In addition, the half-life times of VWF:Ag and VWF:CBA were also measured in four ET patients after cytoreduction of the increased platelet count to normal or nearly normal values. Estimated half-life times of VWF:Ag did not differ between ET patients and normals (11.0+/-4.0 h v 12.4+/-2.5 h, P>0.05). Estimated half-life times of VWF:CBA were significantly lower in ET patients as compared with normal individuals (6.1+/-2.0 h v 8.4+/-2.5 h, P<0.05). After cytoreduction of the increased platelet count to (nearly) normal values in all four ET patients the half-life time of VWF:CBA significantly (P=0.014) increased from 5.2+/-1.2 h to 8.7+/-2.0 h. Our data suggest that platelets may play a role in the homeostasis of circulating von Willebrand factor, which may compromise normal haemostasis at fairly increased platelet counts.
Aged↗
Heparin-induced thrombocytopenia and thrombosis: a prospective analysis of the incidence in patients with heart and cerebrovascular diseases.
Heparin-induced thrombocytopenia and/or thrombosis (HITT) are serious complications of heparin treatment. The incidence, as previously reported, varies widely and, in consequence, is not precisely known. Moreover, most reports only concern clinically defined heparin-induced thrombocytopenia. Therefore we carried out a prospective study of the incidence of serologically confirmed HITT. All patients admitted to the Departments of Cardiology and Neurology of our institution with an indication for treatment with therapeutic-dose intravenous unfractionated heparin were enrolled in the study. The patients were examined daily for the occurrence of thromboembolic complications. Regular platelet counts and tests for the presence of heparin-dependent antibodies were carried out using two different tests: a quantitative platelet factor 4/ heparin (PF4/hep) Elisa, and a functional test, the heparin-induced platelet activation assay (HIPAA). HITT was defined as a rapidly occurring (within 5 d) decrease of the platelet count from normal values of > 120 x 10(9)/l to < 60 x 10(9)/l or to < 100 x 10(9)/l if there was a rapid fall of >50% of starting value or >30% with concomitant acute thrombosis. The observed incidence of HITT was 1/358 patients (0.3%, 95% confidence limits 0.01-1.5%). However, Elisa PF4/hep specific IgG antibodies were demonstrated in nine (2.5%) and IgM antibodies in seven (2.0%) of 358 patients. 30/358 patients (8.4%) had platelet activating antibodies in the HIPAA. We conclude that the incidence of serologically confirmed HITT in this study is very low (0.3%) in patients with cardiac and neurologic diseases treated with intravenous unfractionated heparin. The frequency of heparin-dependent antibodies without concomitant occurrence of thrombocytopenia is much higher.
Adult↗
Atypical HbH disease in a Surinamese patient resulting from a combination of the -SEA and -alpha 3.7 deletions with HbC heterozygosity.
The first case of haemoglobin H (HbH) disease in combination with haemoglobin C (HbC) is reported in a man of Surinamese origin. Only haemoglobin A (HbA) and HbC were detected by electrophoresis. The amount of HbC was much less than expected in HbC heterozygotes. The synthesis ratio (beta A+ beta C/alpha) indicated an alpha-thalassaemia defect with two non-functional alpha genes, which did not correlate with the degree of haemolysis and anaemia displayed by the patient. The DNA analysis of the alpha-genes clusters revealed a defect combination -SEA/-alpha 3.7. The haematological data and the physiopathology of this atypical case are compared with the typical HbH disease found in a first cousin of the propositus. Data on the globin chains expression and on the formation of beta A and beta C homotetramers in HbH/HbC disease are presented.
Adult↗
Prevention and treatment of thrombotic complications in essential thrombocythaemia: efficacy and safety of aspirin.
The efficacy and safety of aspirin in the prevention and treatment of thrombosis in essential thrombocythaemia (ET) was retrospectively analysed in a cohort of 68 ET patients. 41 patients presented with thrombosis, five patients with bleeding: two patients had a paradoxical combination of bleeding and thrombosis at presentation. At presentation, patients with bleeding had significantly higher platelet and leucocyte counts than patients with thrombosis. During long-term follow-up the incidence of thrombosis was significantly reduced in patients receiving aspirin, either as monotherapy or in combination with cytoreduction. However, treatment with aspirin (500 mg/d) was associated with an increase in (minor) bleeding complications. In patients receiving aspirin, bleeding occurred particularly at platelet counts exceeding 1000 x 10(9)/l. The overall 5- and 10-years survival probability was 93% and 84% respectively, indicating that life expectancy in ET is close to normal. Although our data need confirmation in prospective clinical trials, they suggest that aspirin, particularly in lower doses (100 mg/d), may be a safe antithrombotic agent in ET with an acceptable risk for bleeding, if applied to patients with a platelet count <1000 x 10(9)/l and/or absence of a bleeding history.
Adult↗
Essential thrombocythemia in childhood.
In addition to the criteria of the Polycythemia Vera Study Group, positive markers for essential thrombocythemia (ET) include spontaneous BFU-E, splenomegaly, and megakaryocyte morphology in bone marrow smears and biopsy material. The hematologic features of 11 reported cases of ET in childhood showed platelet counts in excess of 1000 x 10(9)/L in all, slight leukocytosis in 8, and splenomegaly in 9. The presenting thrombohemorrhagic manifestations in 8 symptomatic cases were microcirculatory disturbances and transient neurologic ischemic attacks in 2, recurrent mucocutaneous bleedings in 6, and priapism in 1. There are no reports of ET in childhood complicated by microcirculatory disturbances at platelet counts below 1000 x 10(9)/L. Anagrelide and alpha-interferon, which are non-leukemogenic agents for the reduction of platelet counts, may become the treatment of choice in childhood ET. Anagrelide is tolerated better than alpha-interferon. The potential leukemogenic drugs hydroxyurea and busulfan should be used cautiously and withheld as long as possible.
Child↗
Erythromelalgia and thrombocythemia: a disease of platelet prostaglandin metabolism--thesis, Rotterdam, 1981.
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Blood Coagulation↗
Proposal for revised diagnostic criteria of essential thrombocythemia and polycythemia vera by the Thrombocythemia Vera Study Group.
The present study revises the criteria of the Polycythemia Vera Group (PVSG) for the diagnoses of essential thrombocythemia (ET) and polycythemia vera (PV) in view of accumulating data on in vitro cultures of hematopoietic progenitors and by adding histopathology from bone marrow biopsies. The majority of ET patients show spontaneous megakaryocyte or erythroid growth or both, but in about 35% the growth pattern is normal. So far none of the patients with reactive thrombocytosis have shown either spontaneous megakaryocyte or erythroid colony growth. Virtually all PV patients show spontaneous or endogenous erythroid colony (EEC) formation, whereas patients with secondary erythrocytosis and healthy controls do not show any erythroid colony growth in the absence of erythropoietin (EPO). Some rare patients with a disorder other than a myeloproliferative disease (MPD) may show spontaneous growth of erythroid colonies caused by a mutation in the EPO receptor. Megakaryocytes in bone marrow smears and biopsy material from ET and PV patients are typically increased in number and size. Enlarged megakaryocytes with mature cytoplasm and multilobulated nuclei and the tendency of these megakaryocytes to cluster in a normal or slightly increased cellular bone marrow represent the diagnostic hallmark of ET. Increase and clustering of enlarged, mature, and pleiomorphic megakaryocytes in a moderate to marked hypercellular bone marrow with hyperplasia of dilated sinuses is the diagnostic feature of untreated PV. In reactive thrombocytosis and secondary erythrocytosis the size and morphology of megakaryocytes remain normal and there is no tendency of the megakaryocytes to cluster. Both spontaneous EEC and histopathology of bone marrow biopsies appear to offer specific clues to the diagnosis of overt and latent ET or PV and have the potential to differentiate ET from reactive thrombocytosis and PV from secondary erythrocytosis. Moreover, bone marrow histopathology has the diagnostic power to distinguish and to stage the various MPDs without regard to clinical and laboratory data.
Biopsy↗
Erythromelalgia: a pathognomonic microvascular thrombotic complication in essential thrombocythemia and polycythemia vera.
Erythromelalgia is a characteristic thrombotic complication in patients with the myeloproliferative disorders, essential thrombocythemia and polycythemia vera. In this minireview, which is based on more than 20 years of clinical observations and intervention studies, the clinical manifestations, treatment, and pathogenesis of erythromelalgia are discussed.
Blood Platelets↗