Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The discovery of recombinant human erythropoietin has enabled treatment of anaemia in patients whose anaemia was primarily caused by the lack of erythropoietin. This agent was most widely used in the treatment of anaemia in chronic renal failure patients. Non-regulated hypertension is considered to be the only absolute contraindication for recombinant human erythropoietin application, but thrombocytosis, predisposition to thromboses of arterio-venous fistulae, and convulsions are regarded as relative contraindications. Recombinant human erythropoietin may be administered intravenously, but the subcutaneous route is considered more rational. The treatment is initiated by low doses with gradual dose increase, what enables gradual anaemia correction and prevents the appearance of adverse effects. Haemoglobin level of around 100 g/l is considered the target haemoglobin level. The majority of patients respond well to treatment by human recombinant erythropoietin and the absence of anaemia improvement may be the result of iron deficiency, occult haemorrhages, chronic infection, inadequate dialysis, secondary hyperparathyroidism, aluminium intoxication. Anaemia improvement during the treatment with recombinant erythropoietin leads to the improvement of function of most organs and the quality of life in general as well as avoidance of blood transfusions and their adverse effects. The most frequent adverse effect of recombinant erythropoietin is the development of iron deficiency or hypertension aggravation.
 ...
PMID:[Treatment of anemia in patients with chronic renal insufficiency with recombinant human erythropoietin]. 910 27

The effect of recombinant human erythropoietin (rHuEpo) on megakaryopoiesis remains controversial. Treatment with rHuEpo in renal failure patients has been associated with a slight elevation of platelet counts. In animal studies, high doses of rHuEpo produced an increase of platelet counts followed by a gradual return to normal after 7 to 15 days or even a substantial degree of thrombocytopenia. However, because iron deficiency is also known to be associated with thrombocytosis, (functional) iron deficiency during rHuEpo could be contributing to these observations. We investigated the impact of iron supply on changes in platelet counts induced by rHuEpo. Rats were either fed normal food (normal rats) or received 1% carbonyl iron for 2 weeks or 3 months, as well as during the experiment, to achieve iron supplementation or overload, respectively. Rats of all three categories then received daily intravenous injections of rHuEpo (10, 50, or 150 U) or normal saline (0 U) for 20 days. With 0 to 10 U rHuEpo, platelets remained stable. In normal rats receiving 50 to 150 U rHuEpo, platelets increased to 120% to 140% of baseline at 4 to 12 days to level off at 120% at 16 to 20 days. This response was less sustained in splenectomized animals. Iron-supplemented rats receiving 50 to 150 U rHuEpo also increased platelets initially, but the peak was at day 4, followed by a gradual return to baseline and even a moderate thrombocytopenia later on. Iron-overloaded rats receiving 50 to 150 U rHuEpo also had increased platelets at day 4, but the duration of platelet increase was shorter, and they experienced a more pronounced degree of thrombocytopenia in proportion to the dose of rHuEpo. Because the early elevation of platelets was of larger magnitude than hematocrit changes, it is unlikely that it could be accounted for by shrinkage of plasma volume. Because it was observed in all three iron conditions, there appears to be some direct positive effect of rHuEpo on platelet production. However, after this transient effect, expanded erythropoiesis appears to exert a negative impact upon platelet production. Secondary thrombocytopenia was not related to splenic pooling, and its very slow correction after cessation of rHuEpo therapy is not compatible with changes in platelet survival. Rather, it is consistent with stem cell competition between erythroid and megakaryocytic development. However, this secondary thrombocytopenia is masked by (functional) iron deficiency in rats not receiving an adequate iron supply from food or stores.
 ...
PMID:The effect of recombinant human erythropoietin on platelet counts is strongly modulated by the adequacy of iron supply. 1023 80

The present study describes clinicopathological criteria to distinguish the 5 sequential stages proposed by Wasserman et al in the natural history of newly diagnosed PV patients. The European Working Group on MPD (EWG.MPD) extended and modified the PVSG diagnostic criteria of PV by including bone marrow histopathology. From the results of prospective randomized studies in PV it became evident that new clinical trials in previously untreated PV patients should focus on comparing interferon-alpha, a non-leukemogenic approach, versus a potential leukemogenic myelosuppressive treatment modality. Hydroxyurea appears to be the least leukemogenic myelosuppressive agent in long-term prospective clinical PV-studies extending observation periods of more than 10 years. The rational for using IFN-alpha as a first-line treatment option in newly diagnosed PV-patient include its effectiveness to abate constitutional symptoms and to induce a complete remission thereby avoiding phlebotomy, iron deficiency, and macrocytosis associated with hydroxyurea. Moreover IFN-alpha may prevent or delay the development of postpolycythemic myelofibrosis if used early in the course of the disease. Clinicians will be reluctant to postpone the use of hydroxyurea in early stage PV as long as a conservative approach using phlebotomy aiming at a hematocrit below 0.45, plus low-dose aspirin for the control platelet function or anagrelide for the control platelet number is used to keep the patient healthy. Low-dose aspirin will prevent the microvascular thrombotic complications of thrombocythemia associated with PV in remission after phlebotomy, but lacks myelosuppressive activity. Control of megakaryocyte maturation and reduction of platelet production to normal (<400 x 10(9)/l) by relatively low doses of anagrelide will predict a significant reduction of vascular complications in the early stages of PV, may prevent progression to myelofibrosis during follow-up of PV and very probable will postpone the use of hydroxyurea treatment for controlling the platelet count in PV. Large scale randomized clinical trials in PV are proposed, which should aim not only for clinical and hematological response, safety, efficacy, but should also assess toxicity, the need for phlebotomy and whether the development of progressive disease such as splenomegaly, pruritus, myelofibrotic myeloid metaplasia, spent phase, myelodysplasia and acute leukemia can be delayed or prevented by IFN-alpha as compared to a conservative approach of phlebotomy plus low-dose aspirin or anagrelide followed by hydroxyurea when signs of myeloproliferative activity became evident.
 ...
PMID:Diagnosis and treatment of polycythemia vera and possible future study designs of the PVSG. 1067 96

Thrombocytosis is a common feature of myeloproliferative disorders but may also result from various conditions including chronic iron deficiency, hemorrhage, chronic inflammation and splenectomy. We report two cases of secondary thrombocytosis caused by isolated and congenital asplenia, mimicking essential thrombocythemia. These two adult cases of spleen agenesis were unexpected. We conclude that in thrombocytosis without clinical evidence of splenomegaly, attentive screening of blood in search of Howell-Jolly bodies and abdominal ultrasonography should always be performed not only to detect mild spleen enlargement but also to make sure of the presence of this organ.
 ...
PMID:Isolated spleen agenesis: a rare cause of thrombocytosis mimicking essential thrombocythemia. 1106 71

An elevated platelet count is now a common finding in both hospitalized and ambulatory patients with the advent of automated complete blood cell counters. Clinicians may be called upon to make a distinction between a reactive process and a primary hematologic disorder as the cause of a thrombocytosis and to determine whether treatment is indicated. Essential thrombocythemia and other myeloproliferative disorders may present with marked increases in the platelet counts and may be associated with thrombohemorrhagic complications. Reactive thrombocytosis can be caused by iron deficiency and a variety of inflammatory conditions, infections, malignancy, bleeding or hemolysis, splenectomy, and drugs. Acute therapy for all of these disorders has included blood component removal, specifically plateletpheresis. The role of plateletpheresis in current management of thrombocytosis is considered, based on current knowledge of pathophysiology and a review of the literature.
 ...
PMID:The role of blood component removal in essential and reactive thrombocytosis. 1188 75

Anemia was induced in weanling Sprague Dawley rats either by feeding an iron-deficient diet or by chronic phlebotomy. The erythroid regenerative response was then evaluated before and after a hemolytic event, and results were compared with those of a third group of control nonphlebotomized rats fed an iron-replete diet. Diet and phlebotomy groups developed a similar degree of anemia (mean hemoglobin concentration 7.9 g/dL and 7.8 g/dL, respectively; controls, 13.9 g/dL) and hypoferremia (mean serum iron concentration 25.4 microgram/dL and 34.9 microgram/dL, respectively; controls, 222.0 microgram/dL). However, the anemia in diet rats was nonregenerative (reticulocyte count, 83.1 X 10(3) cells/microliter) and associated with bone marrow erythroid hypoplasia; whereas the anemia in phlebotomy rats was regenerative (reticulocyte count, 169.6 X 10(3) cells/microliter) and associated with bone marrow erythroid hyperplasia. Thrombocytosis was seen in diet rats (1,580 X 10(3) cells/microliter) but not phlebotomy rats (901 X 10(3) cells/microliter) when compared with controls (809 X 10(3) cells/microliter). To further evaluate the regenerative capability, phenylhydrazine (PHZ) was administered to induce hemolysis. Erythrocyte mass declined approximately 25% in all groups, including controls. The reticulocytosis (265.3 X 10(3) cells/microliter) seen in phlebotomy rats was earlier and significantly greater than that seen in either diet or control rats. Hemoglobin concentration returned to pre-PHZ concentrations (7.9 g/dL) in phlebotomy rats within 4 days posthemolysis. In diet rats, the maximal regenerative response (176.3 X 10(3) cells/microliter) was not seen until 8 days posthemolysis, and hemoglobin (7.5 g/dL) did not return to pre-PHZ concentrations during the 8-day study. In many aspects, the anemia seen following diet- or phlebotomy-induced iron deficiency was similar. However, the erythroid regenerative capability varied depending on the mechanism by which anemia was induced and furthermore altered the efficiency of hemoglobin production following a hemolytic event. These results suggest that the availability of iron in the diet may modulate the pathogenesis of iron deficiency anemia.
 ...
PMID:Evaluation of the erythroid regenerative response in two different models of experimentally induced iron deficiency anemia. 1202 20

The clinical and hematologic features of two cases of probable essential thrombocythemia in the dog are described. Both dogs presented with hepatosplenomegaly, severe nonregenerative anemia, neutrophilia and Thrombocytosis. Mean platelet volume and percentages of large platelets were markedly increased in both dogs. Platelet aggregation studies demonstrated hyperaggregability in one dog; platelets from the other dog aggregated spontaneously, precluding further investigation. Cytologic and histologic examination of bone marrow showed pronounced megakaryocytic hyperplasia, with erythroid hypoplasia and relative myeloid hyperplasia. Megakaryocyte morphology was abnormal, with increased numbers of small mononuclear and binucleate cells. Normal to increased hemosiderin stores suggested that apparent macrocytosis in one dog, rather than being due to iron deficiency, resulted from the hematology analyzer counting large platelets as small red blood cells. Megakaryocytic infiltration of the spleen was evident in both dogs. The hematologic findings in dogs with essential thrombocythemia can mimic those associated with iron deficiency anemia, such that diagnostic investigations should be aimed at ruling out chronic blood loss and other causes of reactive Thrombocytosis.
 ...
PMID:Diagnostic and hematologic features of probable essential thrombocythemia in two dogs. 1207 9

We investigated the occurence and causes of anaemia and other haematological abnormalities in 142 elderly patients (43 men, 99 women; median age 79 and 80 years), admitted to long-term care. Healthy 81-year-old subjects (n = 220) were used as reference group. Anaemia according to the WHO definition was much more common in the studied population (41%) than in a representative sample of 81-year-old subjects (10%). Somatically fit patients were less often anaemic (30%) than those with somatic illness (68%). The main causes for anaemia were: chronic disease (14.9%), recent haemorrhage (7.8%), iron deficiency (5.7%); and often multifactorial. Secondary leuko- or thrombocytosis occurred in 14 and 23%, drug-induced thrombocytopenia in 2.8% of the patients. Anaemia and other haematological abnormalities seen in elderly patients hospitalized for long-term care are often secondary to chronic or acute disorders. However, they also occur in patients without severe somatic impairment and many of them are reversible. Such findings should therefore not be neglected, but properly investigated, and if possible treated.
 ...
PMID:Anaemia and other haematological abnormalities in patients admitted to long-term care. 1537 90

Major thrombocytosis associated with severe anemia is uncommon in pediatrics. We report 9 consecutive cases observed in Albert Royer Children Hospital of Dakar. They were 7 boys and 2 girls 4 to 15 years old (mean age = 10 years). Six patients had a history of geophagia and 3 presented recent emission of worms by the stools. Anemia was clinically well tolerated in all cases. In initial blood count platelet levels varied from 800 10(3) to 1180 10(3)/mm3 (mean = 1032 10(3)/mm3), while hemoglobin level varied from 3.4 to 7.4 g/dl (mean = 4.9 g/dl). Anemia was microcytic, hypochromic and associated with low serum iron level in all patients. We considered the diagnosis of reactive thrombocytosis induced by iron deficient anemia in all cases. Platelet count and red cell indices were progressively normalised with iron treatment and no complication of thrombocytosis was observed. Considering published data, iron deficiency is one of the most frequent causes of reactive thrombocytosis in children. The physiopathologic mechanism, still unknown, could involve cytokines of thrombopoiesis. Reactive thrombocytosis induced by iron deficiency or other factors have usually a benign course and need no specific treatment other than that of the etiology.
 ...
PMID:[Major thrombocytosis associated with severe anemia in children. Diagnosis of 9 cases]. 1577 94

Reactive thrombocytosis (secondary thrombocytosis) is frequent and typically moderate. We report a case of extreme thrombocytosis and leukocytosis secondary to an iron deficiency anemia. A 21-year-old woman is admitted in emergency department for acute headache. Biological assessment reveals a severe microcytic anaemia (5.4 g/dL) with thrombocytosis (2500 giga/L) and leukocytosis (35 giga/L) leading to multiple diagnosis hypotheses. Finally, biological evaluation concludes to a diagnosis of iron deficiency anaemia related to insufficient oral intake and menorrhagia. Reactive hyperleukocytosis and thrombocytosis rapidly resolved with iron supplementation. This case is a reminder that iron deficiency-related thrombocytosis can sometimes be severe. However, the associated reactive leukocytosis is quite exceptional.
 ...
PMID:[Severe thrombocytosis and leukocytosis associated with iron deficiency anaemia: a case-report]. 1830 30


<< Previous 1 2 3 4 5 6 7 Next >>