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)

The authors describe 22 cases of beta-thalassaemia minor in 11 boys and 11 girls from Czech families. The children suffer as a rule mild hypochromic anaemia with marked microcytosis and rather elevated red cell values. The serum ferritin values are normal, serum iron is normal or slightly elevated. In all children the ratio of haemoglobin A2 is raised (to 4-7%) and in 40% the ratio of haemoglobin F is raised (to 1.5 to 5.9%). There are no differences between boys and girls in the investigated parameters. The boy have, as compared with adult men with beta-thalassaemia minor, significantly lower values of red blood cells and serum ferritin. There are no significant differences between girls and adult women suffering from this disease.
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PMID:[Beta thalassemia in pediatric practice. A group of 22 pediatric patients]. 228 50

The histological features of thalassemic bone are imperfectly known, and the roles of bone marrow hyperactivity, iron overload or vitamin D deficiency in the pathogenesis of the disease are not clearly identified. In this study we examined iliac crest biopsies from 17 transfusion-dependent children with homozygous beta-thalassemia and severe radiological skeletal thalassemic changes, including widening of medullary spaces and osteoporosis. Rachitic lesions were not observed. Serum ferritin concentrations were increased in all but one subject. Iron deposits were histochemically detected in bone marrow, at the marrow-bone interface, along cement lines and mineralizing perimeters. Minor changes were present in trabecular bone, and osteomalacia was absent. By contrast, cortical bone exhibited severe changes including fissures and focal mineralization defects. Plasma 25-hydroxyvitamin D (25(OH)D) concentrations measured during the winter (December-May, 6.5 +/- 4.9 ng/ml, mean +/- SD, n = 6) and during the summer (June-November, 13.8 +/- 8.4 ng/ml, n = 9) did not differ from those of age-matched children living in the same country. Seven patients had moderate hypocalcemia but no biological signs suggestive of vitamin D deficiency: all had normal alkaline phosphatase activity, normal or slightly elevated plasma phosphate, only two had low plasma 25(OH)D concentrations and two others supranormal values of plasma immunoreactive parathyroid hormone. These results show that iron overload and vitamin D deficiency do not seem to play an important role in the pathogenesis of thalassemic bone disease, which is characterized by cortical lesions probably related to marrow hyperactivity.
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PMID:Bone disease in children with homozygous beta-thalassemia. 230 56

Cardiac dysfunction is the most common cause of death in patients with homozygous beta-thalassemia. We studied a group of 10 older patients (mean age 17.5 years) with and without preexisting cardiac dysfunction who had begun chelation therapy on the average of 10 years after regular transfusions were initiated. Over the 4-year study period, two patients were noncompliant with deferoxamine therapy. Their clinical status and cardiac function deteriorated, and both died with evidence of arrhythmia and congestive heart failure. The remaining eight patients were compliant. Despite a drop in mean serum ferritin from 3,814 +/- 577 (SE) ng/ml to 1,056 +/- 146 ng/ml (p less than 0.01), two patients with preexisting cardiac problems and one patient without preexisting heart disease developed further abnormalities. Of the three patients whose status declined, one ultimately improved with alternative chelation therapy. These data suggest that for a few older patients, improvement or stabilization of cardiac status may not be achieved with improved compliance and reduced serum ferritin levels. For these patients, new approaches appear to be warranted. On the other hand, we have demonstrated that in most cases, older patients who began chelation therapy years after transfusions began have benefited from compliance with standard subcutaneous deferoxamine regimens.
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PMID:Chelation therapy and cardiac status in older patients with thalassemia major. 230 80

The ferritin concentration in peripheral blood lymphocyte extracts was measured in 10 normal subjects, 7 patients with homozygous beta-thalassaemia, and 5 patients with iron-deficiency anaemia. The mean intracellular ferritin content was found increased in beta-thalassaemia and reduced in iron-deficient patients. Incubation of mononuclear cells in phytohaemagglutinin medium led to an increase of DNA synthesis concomitant with an increased number of lymphocytes bearing transferrin receptor and interleukin-2 receptor as measured by immunofluorescent technique. Although there was an immunological impairment of lymphocytes in patients with either iron depletion or iron loading compared to normal subjects, their ability to express transferrin receptor and interleukin-2 receptor on their cell surface was normal.
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PMID:Expression of cell-surface transferrin receptor following in vitro stimulation of peripheral blood lymphocytes in patients with beta-thalassaemia and iron-deficiency anaemia. 232 91

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

To investigate the possible causes of an increased incidence of red cell microcytosis in Asian children, 204 Gujarati Asian children and 88 European children attending community infant welfare clinics underwent initial screening tests for determination of red cell indices. Seventy six Asian (37%) and nine European (12%) children had microcytic red cells (mean corpuscular volume less than 74 fl). Further investigation showed that 16 of the Asian children (21%) with microcytosis had thalassaemia trait (eight were heterozygous for alpha thalassaemia and eight for beta thalassaemia), and 50 (66%) had suspected iron deficiency (confirmed by a response to oral iron in 41 cases): the remaining 'microcytic' children were aged less than 2 years, when mean corpuscular volume between 70 and 74 fl may be normal. Increased values for serum total iron binding capacity were more sensitive in detecting iron deficiency than reduced serum ferritin concentrations. Enthusiastic screening for microcytic anaemia in young children may mean that a substantial minority with thalassaemia genes are given unnecessary iron supplements. The response to a short course of oral iron should therefore be carefully monitored, and the possibility of thalassaemia trait as well as non-compliance with treatment should be reconsidered in all those in whom there is little or no response.
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PMID:Microcytosis, iron deficiency, and thalassaemia in preschool children. 237 18

We studied pituitary-gonadal function in 11 male and 5 female patients, aged 12-30 yr, with severe beta-thalassemia and chronic iron overload. All had normal basal serum cortisol, T4, and PRL concentrations and normal serum cortisol and GH responses to insulin-induced hypoglycemia and TSH responses to TRH. Of the 11 male patients (all over 17 yr of age), only 3 attained full pubertal development and 4 had subnormal serum LH and FSH responses to GnRH. As a group, their mean basal serum testosterone (T) level was low [11.7 +/- 4.9 (+/- SE) nmol/L; normal, 10-40 nmol/L], and 9 of the 11 male patients responded to hCG with a rise in serum T. Two of the 3 female patients over 17 yr of age were prepubertal with undetectable serum estradiol (E2) levels and absent serum LH and FSH responses to GnRH; the other female patient had regular menstrual cycles and normal serum E2 levels and LH and FSH responses to GnRH. Six of the prepubertal patients (4 males and 2 females, aged 17-30 yr) were studied serially for 3 yr after the start of chelation therapy. Despite a fall of median serum ferritin from 11,910 to 1,303 pmol/L, there was no progression of puberty, and their basal and GnRH-stimulated serum LH and FSH and serum T or E2 levels did not change. Three of these patients (1 male and 2 female) then received pulsatile sc GnRH therapy in addition to chelation therapy for 6 months with no improvement. We conclude that chronic iron overload in patients with severe thalassemia leads to variable degrees of hypogonadotropic hypogonadism, which do not respond to chelation therapy given late in the course of the disease. The hypogonadism in most patients was due to pituitary hyporesponsiveness to GnRH.
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PMID:Hypogonadotropic hypogonadism in severe beta-thalassemia: effect of chelation and pulsatile gonadotropin-releasing hormone therapy. 249 34

Forty-seven patients with thalassaemia have been studied to define risk factors for development of sensorineural hearing loss, and to establish guidelines for safe chelation. Sensorineural hearing loss was only present in patients who had previously received desferrioxamine (DFO). The two most significant risk factors were the maximum dose of DFO previously received (P less than 0.01), and a serum ferritin of less than 2000 micrograms/l at that time (P less than 0.001). A therapeutic index obtained from the ratio of the mean daily dose of DFO mg/kg divided by the serum ferritin identifies patients with a ratio of greater than 0.025 as at risk of sensorineural hearing loss (P less than 0.001) and can be used as a guideline for safe DFO dosage. Follow-up audiometry of the affected patients over a 2-year period indicated that adjustment of the dose to a therapeutic index of less than 0.025 resulted in the stabilization of hearing loss in seven patients and improvement in two.
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PMID:Desferrioxamine ototoxicity: evaluation of risk factors in thalassaemic patients and guidelines for safe dosage. 260 27

The effect of iron chelation using subcutaneous desferrioxamine on the iron-overloaded heart was studied prospectively over 4 years in 23 asymptomatic patients (mean age 13.2 +/- 5.3 years) with thalassaemia major and transfusion-dependent anaemia. The haemoglobin was maintained greater than 10 g/dl by transfusion and chelation therapy to achieve a negative iron balance. Chelation was closely supervised to ensure compliance. Despite an increase in calculated iron load due to transfusion from 34 +/- 27 g to 63 +/- 28 g, there was a sequential fall in serum ferritin levels from 3148 +/- 1956 ng/ml to 2228 +/- 1825 ng/ml (P less than 0.05). Abnormalities of left ventricular (LV) function, assessed by radionuclide angiography, were present at rest or during exercise in 18 of 23 patients (78%) prior to therapy. Normal LV function was restored in 11 of these 18 patients, five continuing to have abnormal function and two dying. There was a significant increase in resting LVEF from 50 +/- 8% to 57 +/- 6% (P less than 0.01). Peak exercise LVEF rose from 51 +/- 11% to 65 +/- 7% (P less than 0.001). We conclude that the common subclinical abnormalities of LV function induced by iron overload in unchelated patients with thalassaemia major can be reversed with long-term subcutaneous infusions of desferrioxamine.
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PMID:Sustained normalization of cardiac function by chelation therapy in thalassaemia major. 260 72

The pathogenesis of hypochromic anaemia was studied in 138 Saudi bedouin infants aged 9 months. Approximately 25 per cent had hypochromic anaemia, but less than 10 per cent had serum ferritin levels indicative of iron deficiency. A few infants had heterozygous beta-thalassaemia, but many infants with hypochromic anaemia had normal haemoglobin A2 levels together with serum ferritin levels above 20 micrograms/l. DNA analysis of cord blood taken from the hospital where the infants were born showed that the frequency of the single alpha-globin gene deletion type (-alpha 3.7) of alpha-thalassaemia is 0.13 in the bedouin population of Western Saudi Arabia. alpha-Thalassaemia probably accounts for much of the anaemia previously thought to be due to iron deficiency in Saudi infants. Studies of iron status and estimation of the frequency of genetic causes of hypochromic anaemia are important when assessing the need for widespread nutritional programmes to prevent iron deficiency and in the interpretation of reference ranges of red cell indices in populations from malarial areas.
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PMID:The pathogenesis of hypochromic anaemia in Saudi infants. 260 83


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