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)

Thyroid function was investigated by a TRH test in 24 clinically prepubertal children, 3-15 years old with beta-thalassaemia major; in 7 of them the test was repeated once and in 2 twice at intervals of at least 12 months. Basal T4, T3, TBG and TSH levels and the TSH levels during a TRH test were determined and correlated with age and serum ferritin levels. Basal serum T4, T3 and TBG levels were lower and serum TSH levels were higher during the test and in the basal state in thalassaemia major children than in control children. These results show a compensated sub-clinical primary hypothyroidism. The transversal study did not show any significant correlation between the hormonal parameters studied and chronological age or serum ferritin levels. In contrast, the longitudinal study showed a significant correlation between pituitary-thyroidal axis function and siderosis (positive correlations between the variations of TSH levels as delta, peak, 30 and 45 min values and the variations of serum ferritin levels). The thyroid impairment seems not to be correlated with serum ferritin levels in the transversal study because of the presence of an individual different sensitivity of the gland to the iron overload. The ferritin dependence of this impairment is shown only by longitudinal studies where individual differences in sensitivity of the gland are absent.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Endocrine involvement in children with beta-thalassaemia major. Transverse and longitudinal studies. I. Pituitary-thyroidal axis function and its correlation with serum ferritin levels. 643 70

Serum concentrations of T4, T3, rT3, and TSH were measured by radioimmunoassay in 45 patients suffering from beta-thalassaemia. A TRH stimulation test was performed and the binding capacity of TBG and TBPA for T3 and T4 measured by reverse flow zone electrophoresis in a group of these patients. Mean T4 serum concentration was lower in thalassaemic patients than controls; T3, rT3, TSH levels, and the pituitary response to TRH were normal. TBPA binding capacity for thyroxine was greatly decreased, probably due to iron overload impairing the liver function. The decreased circulating total thyroxine might be explained by the reduced TBPA capacity, serum free thyroid hormone concentration total thyroxine might be explained by the reduced TBPA capacity, serum free thyroid hormone concentration values being normal. It is concluded that thalassaemic children are euthyroid, despite often having low-normal or subnormal thyroxine levels.
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PMID:Thyroid function in thalassaemia major. 677 4

The severity of thyroid dysfunction in patients with beta-thalassaemia major is variable in different series. An exaggerated thyrotropin response to thyrotropin-releasing-hormone (TRH) has been found in 1 out of 5 beta-thalassaemia major patients. Because it is not well known how many of these patients will develop overt or subclinical hypothyroidism, we reviewed retrospectively the thyroid status (thyroid hormones, TBG, TG basal and TSH peak after TRH test) of 24 children and adolescents with beta-thalassemia major (mean age 12.1+/-3.9 years) on periodic transfusion therapy, regularly followed in our Centre during the last 20 years. As controls we studied 30 normal subjects aged 13.4+/-2.5 years. In our group of 24 thalassaemics an exaggerated TSH response to TRH test was found in 8 (33.3%), 3 of whom developed subclinical or overt hypothyroidism from 3 to 11 years later. TSH peak values correlated directly with ferritin levels, ALT, and compliance index to chelation therapy. Our data suggest that an exaggerated TSH response to TRH test is frequent in beta-thalassemia major, and may evolve into subclinical or overt hypothyroidism as we found in 37.5% of our patients with sub-biochemical hypothyroidism.
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PMID:Exaggerated TSH response to TRH ("sub-biochemical" hypothyroidism) in prepubertal and adolescent thalassaemic patients with iron overload: prevalence and 20-year natural history. 1933 73