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)

Recurrences of CNS infarction often lead to progressive neurologic disability in sickle cell anemia. To prevent such reccurrence, a periodic blood transfusion program was begun in 1969. Currently, 27 patients are on this regimen. Before inclusion in the program, 12 patients had had one to nine CNS recurrences each. Since the program was started, two patients have had transient CNS ischemia. There were no other recurrences and none of the patients have shown progression of neurologic abnormalities. In addition, there was a striking decrease in bacterial infection and pain. We conclude that periodic transfusions are effective in preventing recurrent CNS infarction in sickle cell anemia. The benefits must be weighed against the potentially serious problem of iron overload, as evidenced by moderately elevated serum ferritin values.
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PMID:Periodic transfusions for sickle cell anemia and CNS infarction. 51 76

Iron overload increases the risk of bacterial infection in dialysis patients, partly by impairing functions of the polymorphonuclear granulocytes (PMNs). PMN defence was studied sequentially in haemodialysis patients with transfusional haemosiderosis, treated for 6 +/- 1.5 months (n = 8) to 13 +/- 1.7 months (n = 4) with recombinant human erythropoietin (rHuEpo). Over this period, signs of iron overload (increased serum ferritin and serum iron) improved, and stainable iron disappeared in PMNs. Simultaneously, phagocytosis of Yersinia enterocolitica by PMNs improved. The decrease in serum ferritin was significantly related to the improved phagocytosis. Killing of Y. enterocolitica by PMNs also improved. It is anticipated that rHuEpo therapy in iron-overloaded dialysis patients could decrease the incidence of bacterial infection by improving PMN functions in these patients.
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PMID:Recombinant erythropoietin reverses polymorphonuclear granulocyte dysfunction in iron-overloaded dialysis patients. 213 Feb 96

Two-wk-old broiler chicks were inoculated via crop intubation with Eimeria acervulina at two doses: 10(5) or 10(6) sporulated oocysts/bird or with Eimeria tenella at a dose of 10(5) sporulated oocysts/bird. Serum and liver samples were collected on days 3 and 6 post-inoculation (PI). There were no significant changes in serum or liver zinc, copper, and iron concentrations in any of the infected groups by 3 d PI. However, on d 6, PI serum protein was significantly reduced in all of the infected groups compared to their pair-fed controls. The chicks infected with E. tenella had significantly reduced serum zinc (1.20 vs 1.77 micrograms/mL) and iron (0.44 vs 1.28 micrograms/mL) concentrations and significantly elevated serum copper (0.28 vs 0.17 micrograms/mL) and ceruloplasmin levels (20.33 vs 11.11 micrograms/mL) compared to their pair-fed counterparts. Those chicks infected with E. acervulina (10(6) oocysts/bird) exhibited significantly reduced serum iron concentration by 6 days PI (0.90 vs 1.14 micrograms/mL). Liver zinc was significantly increased in the chicks infected with E. tenella (349 vs 113 micrograms/g dry liver wt), as was copper (24 vs 19 micrograms/g), whereas liver iron concentration was significantly reduced (172 vs 243 micrograms/g) compared to pair-fed controls. At both dose levels, the chicks infected with E. acervulina exhibited a significant reduction in liver iron by 6 d PI. Hepatic cytosol metals generally reflected whole tissue levels. Metallothionein (MT)-bound zinc was significantly elevated in the chicks infected with E. tenella. Iron bound to a high molecular weight, heat-stable protein fraction (presumably cytoplasmic ferritin) was significantly reduced in chicks infected with E. acervulina, as well as those infected with E. tenella. Collectively, the changes in serum zinc, copper, and iron concentrations, as well as the changes in hepatic zinc and MT-zinc concentrations in the chicks infected with E. tenella were similar to changes evoked during an acute phase response to infection. It is possible that a secondary bacterial infection or inflammation stemming from erosion of the lining of the cecum may play a role in the response of trace element metabolism to the E. tenella infection.
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PMID:Serum and liver zinc, copper, and iron in chicks infected with Eimeria acervulina or Eimeria tenella. 248 59

Iron overload, which is a common complication in haemodialysis patients, is known to enhance bacterial growth and virulence, and to alter phagocytosis. We reviewed the data of 61 haemodialysed patients to clarify the clinical relevance of iron status to the risk of bacterial infection. Increased concentrations of serum ferritin were associated with a greater infection rate (P less than 0.0025), which was already true for ferritin values between 500 and 1000 micrograms/l (P less than 0.025). Furthermore, in 21 iron-overloaded patients treated with an iron-chelator (desferrioxamine), the infection rate decreased from 1/19 patient-months to 1/112 (P less than 0.005), and returned to previous values when desferrioxamine was stopped. Our results demonstrate the importance of haemosiderosis in the increased susceptibility of haemodialysed patients to infections; this susceptibility is decreased by desferrioxamine therapy, which probably acts by restoring phagocytosis and reducing the bioavailability of iron for pathogens.
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PMID:Critical role of iron overload in the increased susceptibility of haemodialysis patients to bacterial infections. Beneficial effects of desferrioxamine. 251 93

During a 19-month period we determined the incidence of bacterial infection among 39 patients treated with desferrioxamine who had end-stage renal disease and were undergoing maintenance hemodialysis. Twenty-three received desferrioxamine because of aluminum-related bone disease, and 16 because of iron overload. A control group of 193 patients on maintenance hemodialysis but without desferrioxamine was used. No difference was found in the incidence of septicemia or of all bacterial infections between the patients with aluminum-related bone disease treated with desferrioxamine and the control patients (0.12 vs. 0.12 septicemia per patient-therapy-year, p greater than 0.05; 0.23 vs. 0.26 bacterial infections per patient-therapy-year, p greater than 0.05). The incidence of septicemia in patients treated with desferrioxamine for iron overload, however, was almost three times that in the control patients (0.36 vs. 0.12 septicemia per patient-therapy-year, p less than 0.01). To assess the effect of iron overload itself, we determined the frequency of bacterial infection in patients on regular hemodialysis who have never received desferrioxamine. These were subdivided into three groups according to serum ferritin level which indicated normal or low iron stores (Group I: serum ferritin 10-330 micrograms/l, n = 125), moderate (Group II: serum ferritin 331-1000 micrograms/l, n = 49) or more advanced iron overload (Group III: serum ferritin 1001-2000 micrograms/l, n = 10). Compared to patients with normal or low serum ferritin levels (Group I), we found a significantly higher rate of bacterial infection among patients in Group II compared with Group I (0.18 vs. 0.34 infections per patient-therapy-year, p less than 0.05) and Group III compared with Group I (0.18 vs. 0.58 infections per patient-therapy-year, p less than 0.01). These results suggest that treatment with desferrioxamine does not favour the development of septicemia or bacterial infection independently of iron overload and that iron overload itself may predispose patients on regular hemodialysis to bacterial infection.
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PMID:Iron overload, but not treatment with desferrioxamine favours the development of septicemia in patients on maintenance hemodialysis. 345 53

Ninety-four per cent of 169 patients with cerebral malaria developed anaemia (haematocrit less than 35 per cent) and 30 per cent required blood transfusion to maintain the haematocrit at more than 21 per cent. Anaemia was at its worst on admission in 58 patients (34 per cent); in the rest the haematocrit fell further, reaching its nadir one to 17 days later (mean 2.3 days). The mean lowest haematocrit was 24.3 +/- 7.2 per cent (+/- 1 SD) and the mean maximum fall was 7.9 +/- 5.6 per cent. Anaemia was more severe in patients with bacterial infection, retinal haemorrhages, schizontaemia and in pregnancy. The lowest haematocrit correlated with admission parasitaemia (r = -0.33, p less than 0.001), total serum bilirubin (r = -0.25, p less than 0.01) and serum creatinine (r = -0.22, p less than 0.01). In 23 patients with uncomplicated falciparum malaria the mean serum iron on admission was 53 micrograms/dl (range 16-157) and the mean serum ferritin 1773 ng/ml (range 170-10 000). There was a significant (p less than 0.001) rise in serum iron 96 h after starting antimalarial treatment; the serum ferritin declined slowly over several weeks. Stainable iron was present in all marrows examined and in eight patients the characteristic pattern of the anaemia of chronic disorders was seen. Seventy-three per cent of patients had dyserythropoiesis which was moderate to gross in 36 per cent. Dyserythropoiesis and erythrophagocytosis were often present on admission but sometimes appeared after the parasitaemia had cleared and persisted for at least three weeks into convalescence. These disturbances in iron metabolism and haemopoiesis are not completely explicable by red blood cell parasitisation. They may contribute more to the anaemia than has previously been recognised.
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PMID:The importance of anaemia in cerebral and uncomplicated falciparum malaria: role of complications, dyserythropoiesis and iron sequestration. 352 85

All adult patients from 13 dialysis centres were prospectively followed up for 6 months in an attempt to appraise the current risk factors for bacterial infections in stable chronically haemodialysed patients. Parameters recorded as potential risk factors for BI were age, gender, cause of renal failure, time elapsed since the start of dialysis, history of transplantation, recent surgical procedure, previous bacterial infection, current immunosuppressive or erythropoietin therapy, type of angioaccess device, and serum ferritin level. Six hundred and seven patients (mean age 56.5 years, range 18-85) were enrolled in the study. Mean time elapsed since the start of dialysis was 4.7 years. One hundred and eighteen patients had developed at least one bacterial infection during the study period whereas 489 had remained free of bacterial infection at the end of the follow-up. In multivariate analysis three parameters were found to be significant and independent risk factors for bacterial infection: previous history of bacterial infection (at least one versus no previous episode), type of angioaccess device (catheter versus native fistula), and elevated serum ferritin level (greater versus lower than 500 micrograms/l). These results support the evidence that impaired host defences in chronic haemodialysis patients may be secondary to the dialysis procedure and suggest that the incidence of bacterial infection in these patients may be further reduced by appropriate supportive therapy.
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PMID:Risk factors for bacterial infections in chronic haemodialysis adult patients: a multicentre prospective survey. 779 34

Highly specialized, state-of-the-art diagnostic tests are available for identifying congenital and acquired immune defects. These methods should only be resorted to when less complicated means have created suspicion of an immune defect. The case history, including the family history, represents the core of the diagnostic procedure. Initially, only simple clinical investigations are indicated. These should enable the physician to exclude or delimit a defect in the immune system which then can be defined more closely by specific tests. Screening includes clinical chemistry (erythrocyte sedimentation rate, total serum protein, serum electrophoresis, C-reactive protein, blood count including differential blood count, ferritin, urine analysis, and a quantitative assay of the immunoglobulins A, G and M), bacteriological, serological, and radiological investigations, and finally skin tests with recall antigens. Thereby, it is usually possible to reliably detect primary B cell defects with humoral antibody deficiency syndromes. Lymphocyte subset counts, immunoelectrophoresis, and bone marrow biopsy are necessary for the differential diagnosis, or for the confirmation, of malignant lymphatic proliferation, especially in adults. IgG subclass defects as well as granulocyte dysfunction and complement defects must be excluded in patients who are susceptible to bacterial infection despite normal immunoglobulin concentrations. In suspected cases of primary or secondary (HIV, cytomegalovirus, Epstein-Barr virus) T cell defects, lymphocyte subset counts and, where applicable, T cell function tests are indicated. The majority of secondary immunodeficiency syndromes, in which the primary disease is known, do not currently require specialized diagnosis. Nevertheless, monitoring of the lymphocyte subsets in HIV-positive patients has already become standard practice in health care (for evaluating the prognosis and deciding on the therapy).
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PMID:[Laboratory diagnosis of immune deficiency]. 849 52

Bacterial infection is a significant cause of morbidity and mortality in hemodialysis patients, and a number of studies have implicated iron overload as a risk factor for bacterial infection in these patients. While the underlying cause of increased susceptibility to bacterial infection is not completely understood, evidence suggests that iron overload alters the chemotactic and phagocytic properties of neutrophils, thereby reducing their ability to kill invading pathogens. T-cell function also appears to be altered. In addition, high levels of serum iron may promote replication and dissemination of bacterial pathogens that use iron as a growth factor. With the introduction of recombinant human erythropoietin therapy for hemodialysis patients, the need for red blood cell transfusions has been reduced and iron overload occurs much less frequently. Several recent studies have indicated that iron overload, which is suspected in the presence of high serum ferritin levels, may no longer be a significant risk factor for infection in hemodialysis patients receiving erythropoietin therapy. Major risk factors for infection in these patients include history of bacterial infection, immunosuppressive therapy, and vascular access via catheters rather than by arteriovenous fistula. In addition, anemia has recently been linked to an increased incidence of bacterial infection, particularly in patients receiving erythropoietin therapy. Therefore, repletion of iron stores and maintenance of iron balance without iron overload may prove to be important factors in reducing the incidence of bacterial infections in hemodialysis patients. However, the relationships between iron levels, anemia, and susceptibility to bacterial infection require further investigation.
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PMID:Iron and infection: clinical experience. 1051 73

Use of erythropoietin (EPO) therapy and iron supplementation has improved the management of anemia in patients with end-stage renal disease (ESRD). As more patients receive supplemental iron, however, concerns are being raised about a potential link between iron and infection. There is biologic plausibility for this link, since iron is a growth factor for bacteria and certain host defense mechanisms are iron-sensitive. Animal models show that injection of iron leads to increased susceptibility to bacterial infection. In some studies, patients with high serum ferritin levels have reduced neutrophil function. However, these studies did not determine whether serum ferritin levels were elevated because of increased iron stores or because of infection. If infection is present, it might cause both the elevated serum ferritin levels and the neutrophil dysfunction. Several clinical studies have found an association between high serum ferritin levels and increased infectious risk. In studies that control for important covariates such as use of catheters and previous infections, the infectious risk associated with iron administration or elevated serum ferritin levels is reduced or eliminated. Collectively, these studies suggest that our current understanding of the relationship between iron and infection is incomplete and further studies are needed. There is no reason to alter current iron treatment strategies based on this literature.
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PMID:Review of issues relating to iron and infection. 1051 76


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