Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The auditory function of 75 children affected by homozygous beta0-thalassemia, managed with a low transfusion scheme and treated irregularly with low doses of desferrioxamine, and of 75 controls were examined. In 12 patients a mild bilateral conductive hearing impairment due to bony hypertrophy and/or adenoid hypertrophy was found. In 43 cases a moderate monolateral or bilateral sensory-neural hearing loss at high frequencies with recruitment phenomenon was observed. Ferritin levels were determined in a randomly chosen group of these patients with (14) and without heaing loss (11). In the subjects with sensory-neural hearing loss the mean ferritin levels were significantly higher than in those with no hearing defect. There was no obvious relation between sensory-neural damage on the one hand and Hb levels and unit of blood transfused on the other. The results of this study suggest that iron overload could be a cause of damage in the high frequency elements of the auditory mechanism. Intermittent hypoxia and slow 8th nerve compression due to bony hypertrophy as causes of auditory involvement are also discussed.
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PMID:Auditory involvement in thalassemia major. 10 1

Homozygous beta-thalassaemia is a disease in which there is a progressive iron overload from infancy to death in early adulthood. Liver biopsies from 10 patients in various stages of this disease were examined by electron microscopy. A number of round or oval lysosomal structures, containing lamellae different from myelin figures, were seen in all patients, including those with minimal iron overload. Ferritin molecules were seen either in relationship with the lamellae forming arrays, or in paracrystalline arrangement, or with no organized form. There were practically no ferritin molecules in sub-cellular compartments other than cell sap and lysosomes. The density of cell sap ferritin was constant beyond infancy, but the number of iron-laden lysosomes increased with age. The stages in the process of iron seclusion, seen even in advanced phases of iron overload, are described. Ferritin is thought to accumulate in lysosomes by a transmembraneous movement, but other explanations are considered.
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PMID:Ferritin in human liver cells of homozygous beta-thalassaemia: ultrastructural observations. 60 78

We studied 29 patients with thalassaemia major who had received intensive chelation for between 6.2 and 8.8 years. All patients had normal oral glucose tolerance tests before subcutaneous chelation therapy was introduced and 22 of 29 patients had normal liver function tests. At the end of the period of study 12 patients still had normal oral glucose tolerance (7 with normal liver function tests and 5 with chronic active hepatitis). On the other hand, 11 patients had developed impaired glucose tolerance tests (3 patients had normal liver function tests, 5 with chronic active hepatitis and 3 with cirrhosis), and 6 patients had developed frank diabetes mellitus (one with chronic active hepatitis and 5 with cirrhosis). Patients with chronic active hepatitis showed 91% positivity for one or more hepatitis B markers whilst all patients with cirrhosis were positive. Ferritin levels before subcutaneous chelation in patients with normal oral glucose tolerance tests were lower than in those patients with abnormal oral glucose tolerance or diabetes (P less than 0.05) but none had normal serum ferritin levels. In addition, a positive correlation was found between glucose area under the curve after chelation therapy and serum ferritin levels (r = 0.47, P less than 0.01). It is apparent that long term chelation therapy does not prevent the development of abnormal oral glucose tolerance in chronically transfused patients. More intensive chelation therapy is needed to prevent tissue damage. Chronic liver disease may have an important role to play in the deterioration of glucose tolerance.
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PMID:The development of diabetes mellitus and chronic liver disease in long term chelated beta thalassaemic patients. 354 13

Serum ferritin, an index of iron stores, was studied in 60 patients with porphyria cutanea tarda (PCT), in 21 patients who had other liver diseases without siderosis (cirrhosis [LC] and chronic active hepatitis [CAH]), and in 32 patients with associated liver siderosis (alcoholic LC, LC and CAH in minor thalassemia). Ferritin levels were higher in patients with porphyria than in healthy controls and patients without liver siderosis (P less than 0.001), whereas no statistical difference was observed between patients with porphyria and those with liver siderosis. Because iron removal is considered the treatment of choice for PCT, some patients with PCT underwent phlebotomy and others received chelating therapy with subcutaneous infusion of deferoxamine. Follow-up of the patients showed a correlation between serum ferritin level and urinary porphyrin excretion; when the clinical and biochemical syndrome became normal, serum iron and ferritin had fallen to normal values (t test pair data analysis before and after: P less than 0.001 in each group). No appreciable difference was found between controls and patients with PCT whose conditions had been normalized, irrespective of the chronic liver damage always present in PCT. Our results suggest that serum ferritin increase in PCT is related more to liver iron overload than to liver damage, and ferritin follow-up is recommended to indicate the exhaustion of hepatic iron stores during iron depletion therapy, as well as to detect an early replenishment after remission.
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PMID:Serum ferritin in the assessment of liver iron overload and iron removal therapy in porphyria cutanea tarda. 394 Dec 93

Some parameters of iron metabolism in 26 patients with porphyria cutanea tarda (PCT) which is often associated with mild iron overload and hepatic siderosis, are studied. Serum iron, percent transferrin saturation and ferritin were pathologically increased. Statistical comparisons were performed between PCT patients and healthy controls, liver disease patients (cirrhosis, chronic active hepatitis) and patients with associated liver siderosis (alcoholic cirrhosis, cirrhosis and chronic active hepatitis in thalassemia). Ferritin levels are higher in patients with porphyria than in healthy controls (p less than 0,001) and in patients without liver siderosis (p less than 0,001). No statistical difference is observed between patients with porphyria and patients with siderosis. A significant decrease in ferritin levels is registered after venesection therapy. The conclusion is drawn that serum ferritin increase in PCT is related to hepatic iron store amounts rather than hepatic necrosis. It is assumed that ferritin follow-up during phlebotomy therapy and also during remission is useful to indicate the exhaustion or an early replenishment of hepatic iron stores.
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PMID:[Determination of serum ferritin in porphyria cutanea tarda. A reliable sign of hepatic siderosis]. 670 23

Ferritin, iron, total iron binding capacity and transferrin saturation were measured in the serum of 247 patients with microcytic hypochromic anemia. Differentiation into various categories of microcytic hypochromic anemia was based on clinical criteria and on the response to iron treatment. This produced 147 patients with iron deficiency anemia, 35 patients with anemia secondary to infection, 27 patients with anemia due to tumor and 38 patients with thalassemia. Analysis of the iron parameters revealed the reliability of both serum ferritin and transferrin saturation in distinguishing between the various forms of anemia. However, measurement of serum ferritin is slightly more reliable and much less expensive than determination of transferrin saturation.
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PMID:[The value of serum ferritin, serum iron and iron-binding capacity in the differential diagnosis of microcytic hypochromic anemia]. 705 13

We evaluated decreasing deferoxamine-induced urinary iron excretion during intensive chelation therapy in four children with thalassemia. Patients received daily intramuscular or subcutaneous therapy as well as intermittent intravenous infusions of high doses of DFO. Iron excretion fell by more than 80% in three patients and decreased by 45% in the fourth. Ferritin concentrations returned to normal or near normal values in all patients. Serum iron concentration and transferrin saturation steadily declined in one of four patients. Supplemental vitamin C was no longer required for normal vitamin C stores or maximum iron excretion in one patient after 26 months of chelation therapy. Interruption of chelation therapy was not followed by increased iron excretion after resumption of treatment with DFO. Decreasing DFO-induced iron excretion occurs during long-term, intensive chelation therapy, and may be the result of substantial reduction of excessive iron stores rather than of tachyphylaxis or transient depletion of an intracellular chelatable iron pool.
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PMID:Response to long-term deferoxamine therapy in thalassemia. 729 39

After successful bone-marrow transplantation (BMT) in thalassaemia, the individual acquires the pattern of globin synthesis of the donor. We call such an individual "ex-thalassaemic after BMT", a term that underscores the cure of the genetic defect but maintenance of residual signs of organ damage due to iron overload and dysfunction acquired during the pretransplant years. We have analysed the extent and fate of tissue iron overload in 151 ex-thalassaemic patients after BMT, according to the risk factors of hepatomegaly, hepatic portal fibrosis, and inadequate chelation therapy. Serum ferritin concentrations decreased and unbound iron binding capacity (UIBC) increased slowly during the years after the transplant. When analysed according to risk group (assigned at the time of the transplant), ferritin and UIBC returned within the normal ranges in only the low-risk group (without hepatomegaly or portal fibrosis, and with adequate chelation pre-BMT). Ferritin and UIBC were still abnormal 7 years after the transplant in the moderate-risk group (those with one or two risk factors) and highly abnormal in the high-risk group (all three risk factors) indicating persistence of, respectively, moderate and severe iron overload at the time of transplant. In ex-thalassaemic patients who were studied before and yearly after the transplant the extent of haemosiderosis, as judged by staining of liver biopsy samples, decreased during the years after transplant. The degree of iron deposition and rate of post-BMT linear growth seem to influence rate of post-BMT decrease in tissue iron overload in different risk groups at the time of BMT.
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PMID:Fate of iron stores in thalassaemia after bone-marrow transplantation. 790 61

Because of continuous blood transfusions, thalassemia patients are subjected to peroxidative tissue injury by the secondary iron overload. In accordance, analysis of serum from 42 beta-thalassemia patients, aged 4 to 40 years, showed that the mean concentrations of conjugated diene lipid hydroperoxides (CD), lipoperoxides evaluated as malondialdehyde/ thiobarbituric acid (MDA/TBA) adducts, and protein carbonyls increased about twofold with respect to control. Ferritin levels were positively correlated with the amount of MDA (r = .41; P = .007) and showed a positive trend with CD (r = .31; P = .07) and protein carbonyls (r = .35; P = .054), as further evidence of the deleterious effects of high tissue iron levels. Marked changes in the antioxidant pattern were also observed in all patients. Evidence is presented of a net drop in the concentration of ascorbate (-44%), vitamin E (-42%), vitamin A(-44%), beta-carotene (-29%), and lycopene (-67%). On the other hand, an increase of uric acid and bilirubin was observed, whereas serum albumin and glutathione were in the normal range in all patients. As a result, the total serum antioxidant potential, measured as trolox equivalent antioxidant capacity appeared significantly decreased by 14%. Serum levels of vitamin E were inversely correlated with ferritin (r = -.45; P = .003), suggesting a major consumption of this antioxidant under iron overload. Nontransferrin bound iron (NTBI) was in the range 4.5 to 54.8 micrograms/dL (mean, 21.8 +/- 13.9). Although NTBI had a positive trend with ferritin (r = .37, P = .03), no clear correlation was found with either MDA or vitamin E. A mild to severe hepatic damage, as assessed by serum transaminases, was shown in 24 of 42 patients. Serum levels of vitamin E (r = -.49, P = .015), vitamin A (r = -.48, P = .016) and lycopene (r = -.47, P = .020), were inversely correlated with the levels of transminases. On the other hand, lipid-soluble antioxidants in thalassemia patients were depleted to the same extent in hepatitis C virus (HCV)-infected (31 subjects) and in HCV-uninfected (10 subjects), while in the normal range in serum from 30 nonthalassemic patients with HCV-related chronic hepatitis. These results point out that the iron-induced liver damage in thalassemia may play a major role in the depletion of lipid-soluble antioxidants. The variations of the parameters evaluated in the present study were not correlated with the age of the patients. Our results suggest that the measurement of peroxidation products, matched with evaluation of antioxidants, may be a simple measure of iron toxicity in thalessemia, in addition to the conventional indices of iron status.
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PMID:Oxidative stress and antioxidant status in beta-thalassemia major: iron overload and depletion of lipid-soluble antioxidants. 889 30

Although alpha+ thalassaemia is the commonest haemoglobinopathy in the world, it is not known if it is associated with significant ineffective erythropoiesis, a fact of importance in interpreting its complex interaction with malaria. To study this problem, we have measured the concentrations of soluble transferrin receptor (sTIR) and ferritin in 181 children from Vanuatu with heterozygous (68) and homozygous (46) alpha+ thalassaemia, and normal controls (67). sTfR concentrations were significantly higher in both homozygotes (mean 3.1 mg/l, range 2.8-3.4) and heterozygotes (2.86 mg/l, 2.6-3.2) compared to the normal controls (2.48 mg/l, 2.3-2.7), suggesting that although globin chain imbalance is minimal, there is ineffective erythropoiesis in both these conditions. Age was also shown to significantly affect sTfR, with peak levels occurring in the 5-9 years age group. Ferritin concentrations showed a similar trend, being higher in the thalassaemic groups, although this did not reach statistical significance. No individuals had low ferritin concentrations, although two had significantly elevated sTfR levels. These observations suggest that the alpha+ thalassaemia phenotype includes an expansion of the erythron, and may suggest possible mechanisms for the increased susceptibility in babies with alpha thalassaemia to both P. falciparum and P. vivax malaria.
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PMID:Alpha thalassaemia is associated with increased soluble transferrin receptor levels. 982 6


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