Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002874 (aplastic anemia)
 5,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case of a 64-year-old Japanese woman who developed aplastic anemia and idiopathic thrombocytopenic purpura with antibody to platelet glycoprotein IIb/IIIa 4 years following a resection of malignant thymoma is reported. Bone marrow was hypocellular and ferrokinetics revealed the prolongation of the half-time of plasma iron disappearance and a decrease in red cell utilization, findings compatible with a diagnosis of aplastic anemia. The life span of platelets was markedly decreased to 3.07 h, and the test for antiplatelet glycoprotein IIb/IIIa antibody was positive. The patient's serum had a suppressive effect on the formation of colonies of burst-forming unit-erythroid and colony-forming unit-granulocyte using normal bone marrow cells. These results suggest that the aplastic anemia in this patient may have been induced by some suppressive activity in the serum. Splenectomy followed by an administration of cyclosporine effectively restored the peripheral blood count.
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PMID:Aplastic anemia and idiopathic thrombocytopenic purpura with antibody to platelet glycoprotein IIb/IIIa following resection of malignant thymoma. 823 73

To aid in the rapid differential diagnosis of thrombocytopenia, the authors developed a latex agglutination test for glycocalicin, a proteolytic fragment of platelet membrane glycoprotein Ib. Plasma glycocalicin determinations were performed for 34 patients with thrombocytopenia. Plasma samples from four patients with aplastic anemia and ten patients with myelodysplastic syndromes, all with glycocalicin levels less than 0.6 mg/L by an enzyme-linked immunosorbent assay, all had negative results by the latex test. In contrast, positive latex agglutination titers were obtained for all 12 patients with idiopathic thrombocytopenic purpura. Eight patients with liver cirrhosis and splenomegaly had elevated levels of plasma glycocalicin, and all of their plasma samples produced agglutination. This latex agglutination test for glycocalicin allows a rapid discrimination of thrombocytopenia caused by impaired platelet production from that caused by increased platelet destruction; thus, it is suitable for use as a screening test in a routine clinical laboratory.
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PMID:Rapid detection of plasma glycocalicin by a latex agglutination test. A useful adjunct in the differential diagnosis of thrombocytopenia. 824 98

Thrombopoietin (TPO), the ligand for c-mpl, stimulates proliferation of committed megakaryocytic progenitors and induces maturation of megakaryocytes. To better understand factors regulating TPO levels, we measured blood levels of TPO in patients with impaired platelet production due to aplastic anemia (AA) and with platelet destructive disorders, including idiopathic thrombocytopenic purpura (ITP), posttransfusion purpura (PTP), drug purpura (DP), and X-linked thrombocytopenia (XLTP). The TPO receptor capture enzyme immunoassay (EIA) used had a detection limit of integral of approximately-150 to 200 pg/mL. TPO was undetectable in 88 of 89 normal individuals. Eighteen of 19 patients with AA and a mean platelet count (MPC) of 18,000/microliters (2,000 to 61,000/microliters) had markedly elevated TPO levels (mean, 1,467 pg/mL; range, 597 to 3,834 pg/mL). Eight AA patients who responded to immunosuppressive therapy with their MPC increasing to 140,000/microliters (92,000 to 175,000/microliters) had substantial decreases in TPO (mean, 440 pg/mL; range, 193 to 771 pg/mL). Initial TPO levels did not differ significantly between responders and nonresponders. In contrast, all 21 patients with ITP and an MPC of 16,000/microliters (1,000 to 51,000 /microliters) had undetectable TPO levels, as did 6 patients with acute PTP or DP and 2 patients with XLTP. Megakaryocyte mass, reflected in the rate of platelet production, appears to be the major determinant of TPO levels in thrombocytopenic patients rather than circulating platelet levels per se. Measurement of serum TPO may be useful in differentiating thrombocytopenias due to peripheral destruction from those due to thrombopoietic failure.
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PMID:Human thrombopoietin levels are high when thrombocytopenia is due to megakaryocyte deficiency and low when due to increased platelet destruction. 863 62

Using enzyme-linked immunosorbent assays, we measured the concentrations of serum thrombopoietin (TPO) and plasma glycocalicin, a proteolytic fragment of platelet glycoprotien Ib alpha, in 13 patients with myelodysplastic syndrome (MDS), aplastic anaemia (AA) or idiopathic thrombocytopenic purpura (ITP). In the patients with AA or MDS, the TPO concentrations were remarkably increased, and their glycocalicin concentrations were decreased compared with the normal control individuals. In the patients with ITP, however, the TPO and glycocalicin levels were not changed as much as in the AA/MDS patients in spite of the same degree of thrombocytopenia. During immunosuppressive treatment of ITP patients, there was an inverse relationship between the level of TPO and the platelet count. Thus, measurements of TPO and glycocalicin levels are useful for the diagnosis of thrombocytopenia, and our results from ITP patients did not support the model which suggested the simple feedback regulation of TPO in thrombocytopenia.
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PMID:Serum thrombopoietin and plasma glycocalicin concentrations as useful diagnostic markers in thrombocytopenic disorders. 869 34

After clinical assessment, pertinent history, and family history, the clinician often has a good idea concerning the cause of a patient's bleeding. The most appropriate laboratory tests can then be ordered. Routine screening tests include a complete blood cell count, platelet count, and evaluation of a peripheral blood sample, a prothrombin time, and an activated partial thromboplastin time. Thrombocytopenia may result from idiopathic thrombocytopenic purpura, disseminated intravascular coagulation, or, less commonly, acute leukemia, aplastic anemia, thrombotic thrombocytopenic purpura, or a particular drug that a patient is taking. Again, the patient's history, physical findings, and evaluation of a well-prepared peripheral blood smear will be helpful in determining the cause of the patient's thrombocytopenia. An isolated prolongation of the activated partial thromboplastin time may result from low levels of factors VIII, IX, or XI. A slightly prolonged activated partial thromboplastin time and a moderate decrease in factor VIII may reflect von Willebrand disease or the "carrier" state for hemophilia A. In women a greatly prolonged activated partial thromboplastin time and very low levels of factor VIII (< 3%) most often result from an acquired factor VIII inhibitor (autoantibody against factor VIII) or from severe (type III) von Willebrand disease. If von Willebrand disease is suspected (because of menorrhagia with or without other mucous membrane bleeding, a positive family history, and a prolonged activated partial thromboplastin time), more specific laboratory tests for this disease should be done. These include assays of factor VIII, von Willebrand factor antigen, von Willebrand factor activity (measured by the ristocetin cofactor assay), and template bleeding time. In von Willebrand disease the defect is in von Willebrand factor. The affected individual may have subnormal levels of structurally and functionally normal von Willebrand factor (this is called "classic" or type I von Willebrand disease) or may produce von Willebrand factor that is structurally and functionally abnormal (von Willebrand disease type 2). Individuals who inherit a gene for von Willebrand disease from both parents have severe (type 3) von Willebrand disease and will have extremely low levels (< 3%) of von Willebrand factor and factor VIII and will have a very prolonged bleeding time. In most populations type I disease is the most common form, whereas type 3 is the least commonly encountered form. It should be noted that levels of von Willebrand factor can be influenced by the patient's blood type (persons who have blood type AB have 60% to 70% higher levels than do persons who have blood type O) and can be elevated during pregnancy, stress, and hyperthyroidism. The two major functions of von Willebrand factor are to serve as a "bridge" between platelets and injury sites in blood vessel walls and to protect circulating factor VIII from rapid proteolytic degradation. Thus, if a patient has either too little or functionally abnormal von Willebrand factor, the bleeding time will be prolonged and factor VIII will be decreased (because it is not being protected by von Willebrand factor). It should be determined which type of von Willebrand disease a particular patient has because treatment depends on type. Multimeric analysis of von Willebrand factor can be done with use of sodium dodecyl sulfate gels, radiolabeled antibody to von Willebrand's factor, and autoradiography. This will allow visualization of the multimeric structure of von Willebrand factor. In type I disease all bands are present, whereas in the type 2 variants 2A and 2B no high-molecular-weight multimers are seen. Desmopressin acetate (which is available in parenteral form for intravenous use and in a highly concentrated intranasal spray formulation) is the treatment of choice for classic type I disease. The drug effects a rapid release of von Willebrand factor from endothelial cell stor
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PMID:Screening and diagnosis of coagulation disorders. 882 61

To clarify the regulatory mechanism of thrombopoietin (TPO, c-Mpl ligand) in chronic thrombocytopenic conditions, we determined TPO levels in the sera of patients with aplastic anaemia (AA; n = 26) and idiopathic thrombocytopenic purpura (ITP; n = 32) by an enzyme-linked immunosorbent assay. Despite a similarity in platelet counts, serum TPO levels in the AA group were markedly higher than those in the ITP group: 20.41 +/- 9.71 f mol/ml (mean +/- SD) and 1.66 +/- 0.55 f mol/ml, respectively, both of which were significantly elevated compared to normal subjects (n = 41; 1.22 +/- 0.37). In both groups, serum TPO level showed an inverse correlation with the platelet count. We determined the megakaryocyte volume using bone marrow clot section and found that it was markedly small in the AA group; while in the ITP group it was augmented with a correlation to serum TPO level. Our findings suggest that TPO levels may be regulated not only by platelets but also megakaryocytes in AA and ITP.
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PMID:Regulation of serum thrombopoietin levels by platelets and megakaryocytes in patients with aplastic anaemia and idiopathic thrombocytopenic purpura. 886 22

To investigate the pathophysiological role of thrombopoietin (TPO) in thrombopoiesis, we measured its serum levels in 15 healthy individuals, 84 patients with various hematological diseases and 2 patients with liver cirrhosis using an enzyme immunoassay procedure. The TPO level was 0.84 +/- 0.40 f mol/ml in normal individuals. TPO levels were considerably elevated in patients with myelosuppression after intensification chemotherapy of acute leukemia in complete remission (postchemotherapy group; n = 18; 18.46 +/- 9.70 f mol/ml). When the data of normal individuals and the postchemotherapy group were combined, TPO levels were inversely correlated with the platelet count in this combined group. We compared these data of normal individuals and the postchemotherapy group with various hematological disease states. In aplastic anemia (n = 13; 16.03 +/- 9.44 f mol/ml), acute lymphoblastic leukemia (n = 5; 10.36 +/- 5.57 f mol/ml), malignant lymphoma (n = 6; 2.79 +/- 2.27 f mol/ml), multiple myeloma (n = 3; 3.34 +/- 0.20 f mol/ml) and chronic lymphocytic leukemia (n = 2; 1.71 +/- 3.91 f mol/ml), the relationship of serum TPO levels and platelet counts was almost the same as in the combined group with normal individuals and the postchemotherapy group. However, the TPO levels were slightly higher in myeloproliferative disorders (n = 12; 1.99 +/- 1.47 f mol/ml) and lower in acute myelogenous leukemia (n = 8; 2.27 +/- 1.25 f mol/ml), hypoplastic leukemia (n = 3; 2.76 +/- 2.23 f mol/ml), myelodysplastic syndrome (n = 2; 0.42 +/- 0.60 f mol/ml), liver cirrhosis (n = 2; 1.50 +/- 0.92 f mol/ml) and idiopathic thrombocytopenic purpura (n = 12; 2.08 +/- 1.41 f mol/ml), when compared to the regression line for the combined group with normal individuals and postchemotherapy group. These findings suggest that TPO might play an important role in regulation of the platelet count in normal and pathological conditions.
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PMID:Serum thrombopoietin level in various hematological diseases. 888 96

To establish a simple computer program for the laboratory diagnosis of anemia and related diseases, multivariate analyses were applied to the results of routine hematological laboratory tests obtained from 48 patients and 51 healthy volunteers. The patients studied were limited to those who had not been treated hematologically by the time of their first visit to our hospital, and their first data obtained in our laboratory were analyzed. Final diagnoses were aplastic anemia (AA) in 21, myelodysplastic syndrome (MDS) in 14, iron deficiency anemia (IDA) in 3, polycytemia vera (PV)in 3, and idiopathic thrombocytopenic purpura (ITP) in 7. Eight parameters, WBC, RBC, Hb, Ht, MCV, MCH, MCHC, and PLT, were transformed to normal distribution and then applied to principal component analysis to evaluate their independence. Very close relationships were observed between Ht and Hb, and between MCV and MCH. One each of these pairs was selected by discriminant analysis and two sets, RBC, MCH, Hb, PLT, and WBC, and RBC, MCV, Ht, PLT, and WBC, were obtained. Two canonical components gave good discrimination of these five diseases and also of normal subjects. When disease prediction was made using this analysis, 37 of 48 patients (77.1%) were predicted correctly, and furthermore, when two disease predictions were allowed, all patients were diagnosed properly. Some overlaps were observed in this two-dimensional coordinate system, especially of AA and MDS, and also with normal subjects. To improve the system further, the additional parameters of age and sex were added to construct a three-dimensional analysis which resulted in much clearer discrimination. The whole procedure described is being developed with subjects who are not taking medication. Subsequently, the general application of this analytical procedure should be limited to only those not on medications. In conclusion, this is in essence a demonstration project; however, this trial of laboratory diagnosis using routine hematological laboratory results appears to be promising. Further extension of the study by increasing numbers of patients and disorders studied, including secondary anemias, will allow the design of diagnostic software for use with personal computers at the sites of primary care.
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PMID:Laboratory diagnosis of anemia and related diseases using multivariate analysis. 903 84

Sixty children with idiopathic thrombocytopenic purpura (ITP) were followed up for 15 to 208 months (mean 120 months) from their first visit. Of these 65% (39 cases) were suffering from acute ITP and 47% of the patients were male. Of the 21 patients with chronic ITP 43% (9 cases) entered remission within five years from the onset of the disease. Conversely patients with chronic ITP for more than five years did not enter remission. Four patients with chronic disease were diagnosed to be other diseases (i.e. three cases were aplastic anemia, the other was Evans' syndrome) after one to four years from the onset. Four patients with chronic ITP for more than five years from the onset are now doing well without any severe bleeding problems. The patients who recovered have had neither problems nor complications. None of the patients died of a cerebral hemorrhage or severe bleeding. We consider that long term outcome of ITP in childhood would be better than that of adult cases.
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PMID:[Long-term follow up of idiopathic thrombocytopenic purpura in childhood]. 931 Dec 68

The serum levels of thrombopoietin (TPO) were measured in 16 patients with thrombotic thrombocytopenic purpura (TTP), 12 with hemolytic uremic syndrome (HUS), 10 with aplastic anemia (AA), 10 with disseminated intravascular coagulation (DIC), and 71 with idiopathic thrombocytopenic purpura (ITP). The serum TPO levels were measured with a sensitive sandwich enzyme-linked immunosorbent assay. The serum TPO level in the ITP group (1.68 +/- 0.85 fmol/ml) were not significantly increased compared with those of the normal subjects. The TPO levels in the TTP (2.77 +/- 1.38 fmol/ml) and HUS groups (5.77 +/- 4.41 fmol/ml) were higher than those of the normal subjects. The patients with AA (12.7 +/- 8.0 fmol/ml) and those with DIC (13.3 +/- 5.7 mol/ml) had significantly higher serum TPO levels than did the normal subjects and ITP patients. The TPO levels were well correlated with the platelet counts in the TTP patients, and were negatively correlated with the platelet counts in the ITP patients. These results suggest that the serum TPO levels in some thrombocytopenic diseases are regulated not only by the platelet count and the megakaryocyte mass, but also by other factors.
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PMID:Increased serum levels of thrombopoietin in patients with thrombotic thrombocytopenic purpura, idiopathic thrombocytopenic purpura, or disseminated intravascular coagulation. 935 24


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