Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Polycythemia vera (PV) is one of the myeloproliferative diseases, and, as such, is an example of clonal hematopoiesis. The progeny of a single, abnormal, hematopoietic stem cell gain a growth advantage over their normal counterparts resulting in overproduction of red cells generally accompanied by overproduction of granulocytes and platelets as well. There are a variety of nonspecific symptoms at onset related to the increased red cell mass and hematocrit accompanied by the more specific manifestations of pruritus, erythromelalgia, and hepatic, portal, and mesenteric vein thrombosis. Splenomegaly and hypertension are common. The laboratory hallmark is an increased red cell mass. There is also often an increase in white cell count, platelet count, and leukocyte alkaline phosphatase along with other findings reflecting the increased rate of turnover of hematopoietic cells. The bone marrow biopsy generally displays hypercellularity involving all three cell lines and absent iron stores. The diagnosis of PV depends on excluding spurious polycythemia in which there is a high hematocrit but a normal red cell mass and secondary polycythemia in which there is an increased red cell mass in response to tissue hypoxia or the inappropriate production of erythropoietin, generally by a tumor. In addition, one should try to establish the diagnosis in a positive fashion by a combination of studies of the blood and bone marrow. Phlebotomy and occasionally plateletpheresis should be used as acute therapy. Chronic therapy is guided by the knowledge that patients treated with phlebotomy alone have an increased rate of thrombotic complications particularly in older patients and those with previous thrombotic disease. Myelosuppressive therapy can reduce the incidence of these complications, but is commonly associated with an increased incidence of second malignancies, particularly acute leukemia. At present, hydroxyurea is the myelosuppressive agent of choice. Antiplatelet agents have a limited role except in the palliation of the syndrome of erythromelalgia. Median survival is approximately 10 years. As implied above, the causes of morbidity and mortality vary with the mode of chronic therapy which has been employed, leukemia being more common after myelosuppressive therapy and thrombotic complications being more common after therapy with phlebotomy alone. Ten percent to 50% of patients move into a spent phase followed by postpolycythemic myeloid metaplasia, irrespective of previous therapy employed. Eventually, the major problems may be cytopenias and massive splenomegaly.
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PMID:Polycythemia vera. 158 7

We recently reported the development of several monoclonal antibodies (MoAbs) to native human erythropoietin (Ep). In the present study we have used the two antibodies with highest affinity to develop a two-sided or sandwich enzyme-linked immunosorbent assay (ELISA) to measure Ep in human serum. In this assay Ep is incubated in microtiter wells precoated with the first (IgE) anti-Ep antibody. Assay wells are then incubated with the second (IgG1) anti-Ep antibody, which is labeled noncovalently with the enzyme alkaline phosphatase (AP) by means of bispecific tetrameric antibody complexes consisting of IgG1 anti-Ep cross-linked to IgG1 anti-AP using rat MoAbs specific for mouse IgG1. Application of this noncovalent labeling procedure, in combination with substrate amplification, results in a detection sensitivity of 0.5 to 1.0 mU/sample (5 to 10 mU/mL), which makes this assay suitable for measuring normal serum Ep levels. The validity of this ELISA for quantitating Ep in biological fluids was demonstrated by the parallelism obtained between pure recombinant Ep dose-response curves and those obtained with plasma and serum from healthy donors and patients with various hematologic disorders. Normal plasma Ep levels detected with this ELISA ranged from 9 to 101 mU/mL with a mean of 32 +/- 23 (SD) mU/mL. Ep levels in sera from patients with polycythemia vera were in the low to normal range, whereas Ep levels in sera from patients with secondary polycythemia and patients with aplastic anemia were moderately to strongly elevated. These results demonstrate that the Ep-ELISA is a sensitive, reliable, and nonradioactive immunologic method for quantitating Ep levels and should prove useful in a variety of clinical and laboratory settings.
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PMID:An enzyme-linked immunosorbent assay for erythropoietin using monoclonal antibodies, tetrameric immune complexes, and substrate amplification. 247 3

Neutrophil alkaline phosphatase activity was estimated in 194 patients; 59 cases of chronic myeloid leukaemia (CML), 42 cases of polycythaemia vera (PV), 24 cases of primary myelofibrosis, 7 cases of idiopathic thrombocythaemia, 6 cases of leukaemoid reaction, 19 cases of secondary polycythaemia (PS) and 37 cases of the primary myelodysplastic syndrome (MDS). According to NAP activities the groups proved to be separate entities (p less than 0.00025). The incidence of decreased NAP score in the CML group was 85% and differed significantly from the other groups as a whole, as well as separately (p less than 0.001). The MDS group, the only group besides CML that showed decreased scores, also differed significantly from the others (p less than 0.001). The PS group, nearly always showing normal scores, differed significantly from the PV group (p less than 0.0052). A method evaluating single cell NAP activity proved superior to the score method in discriminating between the different groups. Thus, the incidence of decreased activity in the CML group was 93% compared with 85% by the score method and the incidences of increased activity in the PV, MP, IT, and LR groups were 79% to 100% compared with 25% to 67% by the score method. The latter difference was statistically significant (p = 0.029).
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PMID:Evaluation of neutrophil alkaline phosphatase (NAP) activity in untreated myeloproliferative syndromes and in leukaemoid reactions. 404 68

Symptomatic erythrocytosis developed in a 59-year-old man with polycystic kidney disease (PKD) while he was receiving maintenance hemodialysis. Major clinical and laboratory data suggested a diagnosis of polycythemia vera (PV), despite a normal serum alkaline phosphatase level and leukocyte count. Secondary erythrocytosis, related to chronic hypoxemia and increased erythropoietin production, was excluded by appropriate laboratory studies. Despite previous documentation of secondary erythrocytosis in patients receiving hemodialysis, to my knowledge, PV has not been described in this population.
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PMID:Polycystic kidney disease and polycythemia vera. Occurrence in a patient receiving hemodialysis. 661 11

A few simple, low-priced, outpatient investigations, including an upper abdominal ultrasonography, a measurement of the arterial oxygen saturation and, in some cases, a leukocyte alkaline phosphatase score (LAP) suffice to find out the etiology of an increased red cell mass in most patients. The diagnosis of polycythemia vera (PV) could be accepted in patients with an increased red cell mass if the spleen is enlarged and if the arterial oxygen saturation is normal, although the latter measurement may not be required in typical cases. If the spleen is not enlarged, the diagnosis of PV could be accepted if, in addition, the leukocyte or thrombocyte count is increased. An elevated LAP score also points to the diagnosis of PV, provided fever or inflammation are not present. If, at that stage, an etiologic diagnosis has not been made, smoker's polycythemia should be considered and excluded. The next step should include a serum erythropoietin assay and culture of erythroid stem cells before performing investigations aimed at ruling out the many conditions associated with secondary polycythemia.
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PMID:Biological and radiological investigations in patients with an increased red blood cell mass: Which are needed? Which are useful? which are unnecessary? 803 33