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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The diagnostic efficacy of hepatic computed tomography density (HCTD) in comparison with serum ferritin for the detection of iron overload was investigated in uremic patients on maintenance hemodialysis (HD) and in patients with idiopathic hemochromatosis (IHC). Ten IHC patients, 38 HD patients and 40 healthy subjects underwent the CT scanning of the liver and determination of percent saturation of transferrin, serum ferritin concentration and HLA typing. Liver iron content was determined by histochemical grading and direct measurement of liver iron concentration either in IHC patients or in HD patients. Nineteen HD patients were considered to have iron overload on the basis of liver iron concentration exceeding 3.6 mumol/100 mg dry weight. The mean +/- SD values of HCTD in healthy subjects, IHC patients, HD patients with iron overload and without iron overload were 60.2 +/- 5.6, 79 +/- 5.6, 71.4 +/- 3.6, 58 +/- 3.8 Hounsfield units, respectively. HCTD showed positive correlations with liver iron concentration and serum ferritin either in IHC patients or in HD patients. The analysis of the diagnostic efficacy of HCTD in comparison with serum ferritin for the detection of excessive hepatic iron in HD patients demonstrated that HCTD had higher sensitivity, specificity, positive and negative predictive values. Cut-off points were arbitrarily fixed to 66 Hounsfield units for HCTD, 400 micrograms/liter for serum ferritin and 3.6 mumol/100 mg dry weight for liver iron concentration. Seventeen HD patients who possessed the histocompatibility antigens associated with IHC, namely HLA-A3 and/or HLA-B7 and/or HLA-B14, had liver iron concentration, serum ferritin and HCTD values higher than those of the HD patients without these "hemochromatosis alleles".(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Efficacy of hepatic computed tomography to detect iron overload in chronic hemodialysis. 231 82

A standard magnetic resonance imaging (MRI) system allowing spin echo times of 10 ms was used to quantitate liver iron concentration in nine healthy normal subjects and 13 patients with various grades of iron overload. Body iron status was estimated by measuring the serum ferritin concentration. In 11 subjects (two normal healthy controls, eight patients with HLA-related hereditary haemochromatosis and one patient with thalassaemia major) non-haem hepatic iron concentration was determined chemically in biopsy specimens (dry weight), in parallel to serum ferritin and MRI-T2 relaxation times. A moderate correlation (r = 0.79) was obtained for the correlation of the T2-relaxation rate (1/T2) and serum ferritin of the 22 subjects investigated. A much closer correlation (r = 0.98) was observed for the 1/T2 liver iron relationship in the 10 subjects analysed by liver biopsy. It is concluded from these preliminary observations, that MR-imaging may provide a useful non-invasive tool for the quantitative determination of liver iron in iron overload-syndromes.
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PMID:Non-invasive quantitation of liver iron-overload by magnetic resonance imaging. 233 43

We determined the prevalence of iron overload due to homozygous haemochromatosis in an asymptomatic Australian (predominantly Caucasian) population by surveying 1968 employees of two large corporations. Subjects were screened by measurement of transferrin saturation and serum ferritin concentration and, in all subjects with elevation of both indices, percutaneous liver biopsy was performed to establish whether significant iron overload was present. The prevalence of iron overload due to haemochromatosis in this population was 0.36%. The prevalence rate was not significantly different between males and females, suggesting that this autosomal recessive disease is expressed equally in females given an adequate dietary iron supply. The positive predictive value of a transferrin saturation consistently greater than 45% together with an elevated serum ferritin concentration was 64%. It is concluded that the prevalence of significant iron overload due to homozygous haemochromatosis warranting treatment is approximately 1:300 and that transferrin saturation should be included in existing adult health screening programmes.
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PMID:Prevalence of haemochromatosis amongst asymptomatic Australians. 234 31

The effect of hepatic iron on the uptake of ferritin was studied by perfusing livers from normal, iron-deficient and iron-loaded rats with 125I-labeled ferritin. Unlabeled ferritin with tracer doses of labeled ferritin in concentrations of 0.02 to 2,700 nmol/L were studied. Rats were made iron deficient by feeding an established iron-deficient diet for 3 wk. Rats were iron loaded by injection of iron dextran (50 mg/wk) for 3 wk. The mean percentage of uptake of ferritin was similar for doses ranging from 0.22 to 22.2 nmol/L of 125I-labeled ferritin. Uptake of ferritin in the normal animal was saturable, with an apparent maximal velocity of uptake of approximately 9.1 pmol/gm/min and a Michaelis-Menten constant of approximately 5 nmol/L at 37 degrees C. Uptake was minimal at 4 degrees C. The mean uptake of ferritin was 78% +/- 10% in the iron-deficient rats (mean hepatic iron = 1.5 mumol/gm), 79% +/- 10% in the normal animals (mean hepatic iron = 9.2 mumol/gm) and 78% +/- 8% in the iron-loaded animals (mean hepatic iron = 192 mumol/gm). In this experimental system, modulation of hepatic iron did not affect uptake of ferritin, suggesting that regulation of the hepatic ferritin receptor may not depend on hepatic iron content. The rapid uptake of ferritin by the liver despite iron overload is consistent with other observations of the nonregulation of non-transferrin-bound iron by hepatic iron and may play a role in the progressive iron overload seen in hemochromatosis.
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PMID:Hepatic ferritin uptake and hepatic iron. 234 54

We assessed the prevalence of previously unrecognized hemochromatosis among patients in whom diabetes mellitus was diagnosed after the age of 30 yr, and we evaluated the positive predictive value of biochemical screening tests for hemochromatosis in diabetic subjects. Thirty-eight of 572 patients screened (6.6%) had a serum ferritin level greater than 324 micrograms/L; 16 patients had normal levels on repeat testing. Four patients' serum ferritin levels fell to less than 400 micrograms/L. Seven of 18 patients with a persistently elevated serum ferritin level did not undergo a liver biopsy because of a recognized cause of hyperferritenemia (carcinoma, alcoholism, or systemic lupus erythematosus). The diagnosis of hemochromatosis seemed certain in 1 of 3 patients who were not biopsied for technical reasons. Of 8 patients biopsied, 2 had hemochromatosis, 4 had fatty liver, 1 had hemosiderosis, and 1 had a chronic inflammatory cell infiltrate with no iron deposition. Of 4 patients with a raised transferrin saturation level, 2 had raised serum ferritin levels and hemochromatosis, 1 had raised serum ferritin and hemosiderosis on liver biopsy, and 1 had a normal transferrin saturation level on repeat testing. Two of 3 cases of hemochromatosis had other clinical markers of the condition. Therefore, routine screening of diabetic patients for hemochromatosis is not necessary, because patients with hemochromatosis will often have other clinical features of the disease. When screening diabetic patients for hemochromatosis, it should be remembered that a persistently raised serum ferritin level has a low positive predictive value (16.6%) and that a normal transferrin saturation level does not exclude the diagnosis.
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PMID:Usefulness of biochemical screening of diabetic patients for hemochromatosis. 235 Oct 33

A bivariate segregation analysis of genetic hemochromatosis with serum ferritin concentration was undertaken to examine the pleiotropic effect of the hemochromatosis locus on each of the two phenotypes, in an ascertained sample of families from Brittany, France. The gene was recessive with respect to both phenotypes, and the estimated gene frequency in the general population was 0.054. Although the ferritin concentration was corrected for the linear relationship with age among controls, there was a residual correlation with age among male family members, consistent with the progressive increase in body iron stores among hemochromatosis homozygotes. This genotype-specific relationship with age illustrates the importance of incorporating interaction effects into analytic models, and suggests that even as a better indicator of progress of disease, rather than liability to disease, serum ferritin concentration serves well to distinguish hemochromatosis homozygotes from alternate genotypes in a family study.
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PMID:Serum ferritin as a marker of affection for genetic hemochromatosis. 236 76

Pedigree studies were performed based on one Faroese and four Danish probands with overt idiopathic hemochromatosis (IH). The study consisted of HLA typing and determination of biochemical iron status indicators (serum transferrin saturation, serum ferritin). In total, 130 persons were evaluated. The screening identified 6 homozygous (h/h) subjects with preclinical IH, 46 heterozygous (h/n), and 8 normal (n/n) subjects, while 39 subjects were classified as normal or heterozygous (n/h?). One family demonstrated both a homozygous x heterozygous as well as a heterozygous x heterozygous mating. Recombination between the HLA region and IH locus occurred possibly in three subjects in three different families. The significance of detailed screening in families with probands with IH is discussed.
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PMID:Family studies of hereditary hemochromatosis in Denmark and the Faroe Islands. 237 54

The value of measurement of hepatic iron concentration and determination of the hepatic iron index in distinguishing homozygotes from heterozygotes for hemochromatosis was examined. The study group included 42 homozygotes with an unequivocal diagnosis of hemochromatosis and six individuals who had initial equivocal results but were established as homozygous after extensive follow-up. These were compared with 15 heterozygotes with no sign of increasing body iron stores who had undergone liver biopsy because of an initial suspicion of raised iron levels. In these subjects a hepatic iron concentration of greater than 75 mumol/gm dry weight was clearly indicative of homozygous hemochromatosis. Body iron accumulation was age-related both in homozygotes and in these heterozygotes with mild biochemical abnormalities (r = 0.476; p = 0.001 and r = 0.689; p = 0.01, respectively), with a rate of accretion of approximately 5 mumol/gm dry weight/year in homozygotes and 0.9 mumol/gm dry weight/year in heterozygotes. Thus, lower values in young subjects may be consistent with homozygosity, and higher values in older individuals are consistent with heterozygosity. To overcome this problem, the hepatic iron index (hepatic iron concentration divided by age in years) was analyzed and found to separate the two groups effectively, with no homozygote having an index of less than 1.9 and no heterozygote having an index of greater than 1.5. These results in a series of patients who have been followed for a median of 3 yr (range = 1 to 30 yr) validate the use of the hepatic iron index to discriminate hemochromatosis homozygotes from heterozygotes with raised levels of serum ferritin, transferrin saturation or both.
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PMID:Identification of homozygous hemochromatosis subjects by measurement of hepatic iron index. 205 Mar 44

Liver biopsy with measurement of hepatic iron concentration is the most certain procedure for evaluation of iron-storage disease, although use of computed tomography and magnetic resonance imaging procedures recently have been proposed as alternative, noninvasive methods for estimating the degree of iron overload. The results of these imaging procedures were compared with those of other noninvasive techniques and liver biopsies in 48 patients. Final diagnoses, based on synthesis of clinical and laboratory data, included (a) primary hemochromatosis (n = 25; 19 homozygous, 6 heterozygous); (b) secondary hemochromatosis (n = 7); (c) alcoholic liver disease (n = 11); (d) chronic active hepatitis (n = 3); and (e) other (n = 2). Serum ferritin and computed tomography or magnetic resonance scanning had 100% sensitivity in detecting hepatic iron overload more than fivefold above the upper limit of normal (greater than 10.7 mumol Fe/100 mg dry liver) but did not detect lesser degrees of iron overload reliably, including those found in 6 of 13 patients with untreated homozygous primary hemochromatosis and 3 of 7 with secondary hemochromatosis. Computed tomography and magnetic resonance imaging were more specific than ferritin (64% and 92% vs. 21%) in the detection of iron excess, more than five times the upper limit of normal. Among magnetic resonance imaging measures, the ratio of the second echo signal intensities of liver to paraspinous muscle was the most sensitive and most specific for detection of this degree of iron overload. The degree of correlation between hepatic iron concentration and results of noninvasive laboratory or imaging studies were insufficient to permit prediction of hepatic iron content by noninvasive studies alone. It is concluded that computed tomography or magnetic resonance scanning as currently usually used is not cost-effective in routine evaluation of iron overload, although these imaging procedures may play a role in patients in whom liver biopsy is contraindicated. Because of their low cost and ready availability, serum ferritin and transferrin saturation tests remain the preferred screening studies for iron overload. Liver biopsy with quantitative iron measurement remains the study of choice for the definitive diagnosis of hemochromatosis.
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PMID:Usefulness and limitations of laboratory and hepatic imaging studies in iron-storage disease. 239 29

Plasma from patients with iron overload resulting from idiopathic hemochromatosis contains nontransferrin-bound iron, measurable by the bleomycin, assay. During venesection therapy, the concentration of bleomycin iron declines in a way highly correlated with plasma ferritin concentrations. Even when patients had been venesected to give very low total plasma iron concentrations and high transferrin iron-binding capacity, bleomycin-detectable iron was still present at low concentrations. Bleomycin-detectable iron can stimulate damaging free radical reactions, and its persistence in plasma even after prolonged venesection might contribute to the tissue damage that results from iron overload.
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PMID:Nontransferrin-bound iron in plasma from hemochromatosis patients: effect of phlebotomy therapy. 245 83


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