Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two siblings were identified with severe hypoproliferative microcytic anemia and iron malabsorption, in the absence of any gastrointestinal disorder or blood loss. These children had severe microcytosis (MCV 48 fl, hemoglobin 7.5 g/dl) with decreased serum iron, elevated serum TIBC, and decreased serum ferritin, despite prolonged treatment with oral iron. An iron challenge study with an oral dose of 2 mg/kg elemental iron as ferrous sulfate documented iron malabsorption. After treatment with intravenous iron dextran, there was an absence of the expected reticulocytosis and only a partial correction of the hemoglobin, hematocrit, and microcytosis. The bone marrow was hypocellular with abnormal iron incorporation into erythroid precursor cells. This appears to be a rare form of inherited anemia characterized by iron malabsorption and disordered iron metabolism that only partially corrects after the administration of parenteral iron. These features resemble those found in the microcytic mouse (mk/mk), which also has severe microcytic anemia and iron malabsorption that partially responds to parenteral iron.
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PMID:Microcytic anemia with iron malabsorption: an inherited disorder of iron metabolism. 949 83

Systemic-onset juvenile chronic arthritis (SoJCA) is associated with high levels of circulating interleukin-6 (IL-6) and is frequently complicated by severe microcytic anemia whose pathogenesis is unclear. Therefore, we studied 20 consecutive SoJCA patients with hemoglobin (Hb) levels <12 g/dL, evaluating erythroid progenitor proliferation, endogenous erythropoietin production, body iron status, and iron supply for erythropoiesis. Hb concentrations ranged from 6.5 to 11.9 g/dL. Hb level was directly related to mean corpuscular volume (r = .82, P < .001) and inversely related to circulating transferrin receptor (r = -.81, P < .001) suggesting that the severity of anemia was directly proportional to the degree of iron-deficient erythropoiesis. Serum ferritin ranged from 18 to 1,660 microgram/L and was unrelated to Hb level. Bone marrow iron stores wore markedly reduced in the three children investigated, and they also showed increased serum transferrin receptor and normal-to-high serum ferritin. All 20 patients had elevated IL-6 levels and normal in vitro growth of erythroid progenitors. Endogenous erythropoietin (epo) production was appropriate for the degree of anemia as judged by both the observed to predicted log (serum epo) ratio 10.95 +/- 0.12) and a comparison of the serum epo-Hb regression found in these subjects with that of thalassemia patients. Multiple regression analysis showed that serum transferrin receptor was the parameter most closely related to hemoglobin concentration: variation in circulating transferrin receptor explained 61% of the variation in Hb level (P < .001). In 10 severely anemic patients, amelioration of anemia following intravenous iron administration resulted in normalization of serum transferrin receptor. Defective iron supply to the erythron rather than blunted epo production is the major cause of the microcytic anemia associated with SoJCA. A true body-iron deficiency caused by decreased iron absorption likely complicates long-lasting inflammation in the most anemic children, and this can be recognized by high serum transferrin receptor levels. Although oral iron is of no benefit, intravenous iron saccharate is a safe and effective means for improving iron availability for erythropoiesis and correcting this anemia. Thus, while chronically high endogenous IL-6 levels do not appear to blunt epo production, they are probably responsible for the observed abnormalities in iron metabolism. Anemia of chronic disease encompasses a variety of anemic conditions whose peculiar features may specifically correlate with the type of cytokine(s) predominantly released.
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PMID:Defective iron supply for erythropoiesis and adequate endogenous erythropoietin production in the anemia associated with systemic-onset juvenile chronic arthritis. 863 55

Although the full mechanisms are not yet elucidated, research into the mechanism of toxicity of aluminum (Al) on bone formation and remodeling and on hematopoietic tissue is ongoing. In contrast little information exists on the interactive effects of systemic Al and the kidney. In bone, both clinically and experimentally, high doses of Al inhibit remodeling, slowing both osteoblast and osteoclast activities and producing osteomalacia and adynamic bone disease. In contrast, while very low levels of Al are mitogenic in bones of experimental animals, the effect of low levels of Al in humans is unknown. Aluminum has been shown to have its mitogenic action at the osteoblast, but whether the effect on resorption is viz osteoblast-directed changes in osteoclast activity has not yet been determined. Parathyroid hormone (PTH) levels are disrupted by Al in humans and animals. Whether altered PTH levels play a major or even a minor role in Al-dependent osteotoxicity requires clarification. In hematopoietic tissue, Al causes a microcytic anemia, not reversible by iron. Friend leukemia cells treated with Al have been reported to accumulate excess iron, without incorporating it into ferritin or heme. It is not yet known which steps in iron metabolism are disrupted by Al, if they involve a single mechanism of action, or even if this disruption in iron metabolism accounts for the anemia seen in Al toxicosis. In kidney, research is needed to evaluate Al nephrotoxicity; there are almost no studies in this area. Furthermore, research is needed to evaluate mechanisms of renal Al excretion, presently shown by one study to occur at the distal tubule. Such studies might well throw light on whether Al plays a role in aggravating renal insufficiency, or whether the role of the kidney in Al toxicosis is limited to the causative effect of renal compromise on Al accumulation. In summary, while a number of mechanisms have been proposed for the toxic action of Al, no single mechanism emerges to explain these diverse effects of systemic Al. Recommendations for future research are presented and summarized in Table 1.
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PMID:Systemic aluminum toxicity: effects on bone, hematopoietic tissue, and kidney. 877 4

Because anemia is a condition rather than a disease, an underlying cause must be determined when anemia is identified. Microcytic anemia is a common category of anemia. Iron deficiency anemia is the most common type of microcytic anemia and is also the most common anemia. The clinical presentation of anemia varies according to its severity. Anemias resulting from chronic disease and thalassemia are also relatively common types of microcytic anemia and should be differentiated from iron deficiency to avoid repeated unnecessary trials of iron therapy. Low serum ferritin is the best single laboratory parameter for the diagnosis of iron deficiency. Serum iron, total iron binding capacity and hemoglobin electrophoresis, if necessary, can help differentiate the type of microcytic anemia in patients with normal or elevated levels of serum ferritin. If the evaluation identifies iron deficiency as the type of anemia, the underlying cause must be investigated.
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PMID:Microcytic anemia. 916 44

During a 7-month period a prospective study of 71 anaemic patients (29 males and 42 females) over the age of 50 was undertaken in order to identify patients with myelodysplastic syndrome (MDS). The mean values of mean corpuscular volume (MCV), serum ferritin, folate, vitamin B12 and red cell folate (RCF) of patients grouped according to the diagnosis were compared to those observed in age-matched blood donors. Forty-four of the 71 elderly patients showed macrocytic anaemia: 21 of them had gastric disease and the remaining 23 MDS. Two further patients with MDS showed microcytic anaemia. The 25 patients diagnosed with MDS were subclassified according to the FAB nomenclature: 9 had a refractory anaemia with excess of blasts and 16 refractory anaemia. The mean values of MCV, serum folate, ferritin, vitamin B12 and RCF were statistically different between patients with macrocytic anaemia due to gastric disease and patients with MDS. Among patients with MDS, the RCF level pathologically high was inversely correlated to the haemoglobin level (r=-0.39; p<0.05). Thus the RCF and serum folate may represent useful parameters for the diagnosis of MDS in elderly anaemic patients.
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PMID:Red cell folate in elderly patients with myelodysplastic syndrome. 975 11

Chloramphenicol is an antibiotic that consistently suppresses the bone marrow and induces sideroblastic anemia. It is also a rare cause of aplastic anemia. These toxicities are thought to be related to mitochondrial dysfunction, since chloramphenicol inhibits mitochondrial protein synthesis. We hypothesized that chloramphenicol-induced mitochondrial impairment alters the synthesis of ferritin and the transferrin receptor. After treating K562 erythroleukemia cells with a therapeutic dose of chloramphenicol (10 microg/ml) for 4 days, there was a marked decrease in cell surface transferrin receptor expression and de novo ferritin synthesis associated with significant decreases in cytochrome c oxidase activity, ATP levels, respiratory activity, and cell growth. Decreases in the transferrin receptor and ferritin were associated with reduced and unchanged message levels, respectively. The mechanism by which mitochondrial dysfunction alters these important proteins in iron homeostasis is not clear. A global decrease in synthetic processes seems unlikely, since the expression of the cellular adhesion proteins VLA4 and CD58 was not significantly decreased by chloramphenicol, nor were the message levels of beta-actin or ferritin. The alterations were not accompanied by changes in binding of the iron response protein (IRP) to the iron-responsive element (IRE), although cytosolic aconitase activity was reduced by 27% in chloramphenicol-treated cells. A disturbance in iron homeostasis due to alterations in the transferrin receptor and ferritin may explain the hypochromic-microcytic anemia and the accumulation of nonferritin iron in the mitochondria in some individuals after chloramphenicol therapy. Also, these studies provide evidence of a link between mitochondrial impairment and iron metabolism in K562 cells.
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PMID:Chloramphenicol-induced mitochondrial dysfunction is associated with decreased transferrin receptor expression and ferritin synthesis in K562 cells and is unrelated to IRE-IRP interactions. 1043 Jan 73

Red cell haemolysates of 627 patients with mainly microcytic anaemia were subjected to HPLC for diagnosis of thalassaemia (thal) or haemoglobinopathy during 1998. Thalassaemia was diagnosed in 16.3% (95 beta-thal minor, 1 beta-thal major, 2 delta beta-thal heterozygote, 4 alpha-thal1), haemoglobinopathies in 3.5% (10 Hb S including 3 Hb S-alpha-thal, 1 homozygote, 1 Hb SC and 1 Hb SE; 6 Hb E including 3 homozygotes; 3 Hb Lepore heterozygotes; 1 Hb K; 1 Hb O-Arab*; 1 Hb K-Ibadan* [* = confirmed by DNA sequencing]). In 10.7% of patients severe iron-deficiency (ferritin < 7 micrograms/l) was the cause of microcytosis (MCV 72.1 +/- 2.6 fl) and anaemia (Hb 97.2 +/- 9.8 g/l). The beta-thal minor group showed prominent microcytosis (MCV 66.9 +/- 2.6 fl) but only mild anaemia (Hb 114.1 +/- 12.9 g/l). Variant Hb K-Ibadan und Hb O-Arab were found during quantification of HbA1c. Patients with beta-thal minor or severe iron-deficiency anaemia were identified with equal frequency in adult females, children and adolescents of both sexes; however, in adult males beta-thal minor was the most frequent aetiology (> 90%) of microcytic anaemia. Our results demonstrate the diagnostic value of red cell lysate HPLC and ferritin determination when evaluating unclear microcytic anaemia. This approach, together with die HbA1c-quantification by HPLC, will render possible detailed diagnosis of thalassaemia and haemoglobinopathies.
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PMID:[Diagnosis of thalassemias and hemoglobinopathies by HPLC (high performance liquid chromatography): study of 627 patients]. 1048 59

We encountered two patients who presented with hypochromic-microcytic anemia and were refractory to iron therapy. The symptoms were suggestive of anemia of chronic disease (ACD); however, there was no evidence of any such disease, either inflammatory or malignant. These patients were reminiscent of patients originally described as having primary defective iron reutilization. The hematologic picture consisted of hypochromic-microcytic anemia, low serum iron, low to normal iron binding capacity, high serum ferritin, and increased bone marrow iron in the absence of ringed sideroblasts. These patients had symptomatic anemia and received danazol (200 mg orally) three times per day to which they responded very well with an increase of approximately 3 g in the hemoglobin concentration over 1 year and amelioration of their symptoms. Danazol was well tolerated and did not cause any virilizing side effects. Doses were lowered in maintenance after 1 year to 200 mg once per week, and responses were sustained up to 36 months of follow-up duration. In the differential diagnosis of hypochromic-microcytic anemia, especially in postmenopausal women, one has to consider this type of treatable anemia when more common types such as iron deficiency, chronic inflammation, malignancy, sideroblastic anemia, or thalassemia have been ruled out.
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PMID:Treatment of primary defective iron-reutilization syndrome: revisited. 1098 70

The iron status and diet of Inuit infants living in northern Quebec who were part of a prospective cohort study was described. The prevalence of anemia (hemoglobin values > 2 SD below the reference mean) was 21.1% (23/109), 47.4% (55/116) and 37.7% (46/122) at 2, 6 and 12 months, respectively. The corresponding prevalence of microcytic anemia was 0.0%, 4.3% and 21.3%. At 2, 6 and 12 months, iron-deficiency anemia (serum ferritin < 10 micrograms/L coupled with anemia) was present in 1.3% (1/79), 24.4% (21/86) and 26.3% (25/95) of infants, respectively. Compared with breastfeeding, the odds ratio for iron deficiency (serum ferritin < 10 micrograms/L) for bottle-feeding with cows' milk or low iron formula was 3.02 (95% CI 1.25-7.27) at 6 months and 3.05 (95% CI 1.28-7.28) at 12 months. This study shows iron-deficiency anemia to be a problem in Inuit infants as young as 6 months old. Breastfed infants were better protected against iron deficiency than infants fed cow's milk or low-iron formula.
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PMID:Anemia and iron status in Inuit infants from northern Quebec. 1120 Jul 28

Iron deficiency is a common cause of microcytic anaemia. However, a high prevalence of haemoglobinopathies in the Arab population makes differential diagnosis difficult. This prospective study of anaemia in children attending a regional hospital in the Sultanate of Oman looked at the prevalence and causes of anaemia in 256 children, 153 in the age group 3-5 years (group A) and 103 in the age group 10-12 years (group B). Of the children studied, 45.1% in group A and 37.9% in group B were anaemic according to WHO criteria. All the anaemic children had low mean corpuscular haemoglobin and 75% showed microcytosis. Serum ferritin levels were normal and glucose-6-phosphate dehydrogenase deficiency did not contribute to the anaemia. The microcytosis and microcytic anaemia in the study population could be attributed to the alpha-thalassaemia trait which is highly prevalent in Oman. The information is of value in any country where there is a significant prevalence of alpha-thalassaemia genes because these can confound the diagnosis of iron deficiency.
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PMID:High prevalence of microcytic anaemia in Omani children: a prospective study. 1128 46


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