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)

A 13-year-old Thai female with hemoglobin E-beta-thalassemia was evaluated for anemia and splenomegaly. Globin chain synthesis in a whole cell system revealed an absence of betaA chains and excessive alpha chains. The alpha/betaE + gamma ratio was 1.26 in bone marrow and 1.90 in peripheral blood. The average gamma/betaE ratio in bone marrow and peripheral blood was 0.36 compared to peripheral blood concentrations of 49% hemoglobin E and 51% hemoglobin F. Homologous red cell 51Cr half-life increased from 22.7 days to 32.8 days after splenectomy. Total circulating hemoglobin increased from 112.9 to 149.7 g. Endogenous carbon monoxide productive (Vco) as a measure of total heme catabolism decreased from 2.00 to 1.54 mumol/hr/kg. Ineffective erythropoiesis was manifested by an increased Vco/Vheme-c ratio of 7.52.
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PMID:Splenic sequestration and ineffective erythropoiesis in hemoglobin E-beta-thalassemia disease. 72 94

Pulmonary function tests were evaluated in 28 Chinese patients with beta-thalassemia major receiving regular transfusions and desferoxamine, and in 34 height-matched normal Chinese children. Comparison of lung function using analysis of covariance with reference to standing height showed that patients with thalassemia had a proportional decrease in forced vital capacity and forced expiratory flow volume in 1 second, whereas their expiratory flow rates, residual volume, and total lung capacity were comparable to those in normal children. The single-breath carbon monoxide diffusion capacity was normal. Our findings suggest that children with thalassemia major have mild restrictive lung disease. The previous controversy regarding the presence of restrictive or obstructive lung disease in patients with thalassemia may be related to the use of inappropriate control values.
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PMID:Pulmonary function in thalassemia major. 365 83

Pulmonary function tests were performed on 30 patients with beta-thalassemia/Hb E. Only one patient had normal pulmonary function. Arterial hypoxemia at rest was present in 22 of 30 patients (73.3%). Abnormal VC, FEV1, FEV1/FVC, and end tidal FEV1 were found in 29 (96.7%), 17 (56.7%), 6 (20.0%), and 17 (56.7%) patients, respectively. Single-breath carbon monoxide diffusing capacity was abnormal in one out of 11 patients (9.1%). These results suggest the presence of abnormal ventilatory function included restrictive, obstructive, and combined defects. The hypoxemia in thalassemia was probably due to ventilation/perfusion mismatch and a diffusion defect.
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PMID:Lung function tests in splenectomized beta-thalassemia/Hb E patients. 368 19

Pulmonary function tests were performed on 19 patients with homozygous beta-thalassemia ranging in age from 10 to 29 years. These included patients who had and had not received transfusions. None of the 19 subjects had completely normal pulmonary function. Residual volume (in 16 of 19 patients), ratio of residual volume to total lung capacity (12 of 19), and airway resistance (16 of 19) were abnormally increased; maximum expiratory flow (15 of 19) and peak flow (10 of 19) were abnormally reduced. Single-breath carbon monoxide diffusion was normal in 16 of 19. These results indicate that mild to moderate small airway obstruction and hyperinflation are common in thalassemia and that patient age, transfusion history, and iron accumulation are not important factors in the genesis of these pulmonary abnormalities.
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PMID:Pulmonary function abnormalities in homozygous beta-thalassemia. 374 33

The rate of endogenous carbon monoxide production ( Vco), determined by the closed rebreathing system technique, was elevated above the normal range in four of five patients studied with ineffective erythropoiesis (four patients with primary refractory anemia, one with thalassemia). The mean molar ratio of Vco to Vheme (rate of circulating heme catabolism, determined from (51)Cr red cell survival curves) was 3.0 +/- 0.6 (SE), indicating that most of the CO originated from sources other than circulating erythrocyte hemoglobin, in contrast to previous findings in patients with hemolytic anemia, where Vco paralleled Vheme closely.After administration of glycine-2-(14)C to these patients, endogenous CO was isolated by washout of body CO stores at high pO(2) or by reacting peripheral venous blood samples with ferricyanide. The CO was then oxidized to CO(2) by palladium chloride and trapped for counting in a liquid scintillation spectrometer. "Early labeled" peaks of (14)CO were demonstrated which paralleled "early labeled" peaks of stercobilin and preceded maximal labeling of circulating heme. Production of "early labeled" (14)CO in patients with ineffective erythropoiesis was greatly increased, up to 14 times that found in a normal subject. The increased Vco and "early (14)CO" production shown by these patients are presumably related mainly to heme catabolism in the marrow. The possibility exists that hepatic heme and porphyrin compounds may also contribute significantly to Vco, as suggested by the finding of a high Vco in an additional patient with porphyria cutanea tarda.
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PMID:Carbon monoxide production associated with ineffective erythropoiesis. 607 3

Pulmonary function tests were performed in 12 thalassemia patients on a hypertransfusion program (age 18.4 +/- 2.6 SEM years) to determine the presence of any abnormalities of lung function. These included spirometry, expiratory flow rates, body plethysmography, single-breath nitrogen washout, single breath carbon monoxide diffusing capacity, and arterial blood gases. Only one patient had normal pulmonary function. Arterial hypoxemia was present in ten of 12 patients at rest. The total lung capacity (TLC) was normal. The residual volume was abnormally increased in five of 12 patients. The slope of phase III of single breath nitrogen washout curve was abnormal in five of 12 patients, but the closing volume was normal. The maximal expiratory flow rate at 60% total lung capacity was decreased in four of 12 patients, suggesting the presence of small airway disease. The single breath carbon monoxide diffusing capacity was normal in all patients. These pulmonary function abnormalities did not correlate with age or the cumulative amount of iron via blood transfused. The small airway obstruction, hyperinflation; and hypoxemia observed in thalassemia patients on a hypertransfusion program may result from the basic disease, iron deposition in the lungs, or other factors.
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PMID:Pulmonary function abnormalities in thalassemia patients on a hypertransfusion program. 736 14

We evaluated lung function in 17 children with thalassemia major in stable condition receiving blood transfusions at regular intervals and subcutaneous desferoxamine daily. Total lung capacity (TLC) was below 2 SD of normal values for height in 7 of the 17 children and arterialized capillary PO2 was below the normal range in 15. We studied lung mechanics in 4 children with reduced TLC and found static and dynamic compliance below 2 SD of normal values for height in 3, and lung recoil at TLC above normal values and specific upstream conductance (Gus/TLC) above 2 SD of normal values in all 4. Although these alterations in lung function have been described in patients with pulmonary fibrosis, we found no fibrosis in autopsy specimens of lung from 8 other patients with thalassemia. The rate constant of carbon monoxide diffusion (kCO) was above the predicted mean in 14 of 15 children. These findings can be explained by a decrease in the growth of airspace relative to the vascular bed and major airways during childhood.
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PMID:Low lung capacity and hypoxemia in children with thalassemia major. 738 77

Progressive tissue iron deposition from multiple blood transfusions is common in beta-thalassaemia and pulmonary iron deposition may result in parenchymal damage. The objectives of this study were to: 1) determine the predominant pulmonary dysfunction in patients with thalassaemia major; and 2) demonstrate that parenchymal disease, if present, is at the level of the alveolocapillary membrane. Fourteen thalassaemia major patients (13 nonsmokers) receiving regular blood transfusion and without any history of chronic respiratory disease were recruited. Pulmonary function tests and echocardiography were performed before the scheduled transfusions. Three patients with the most restricted lung function were selected for high resolution computerized tomography (CT) of the lungs. One patient had an obstructive pattern with a forced expiratory volume in one second as percentage of forced vital capacity (FEV1/FVC) of 71%. Four patients demonstrated a restrictive pattern, as defined by total lung capacity (TLC) less than 80% predicted with normal FEV1/FVC%. Twelve patients had pulmonary transfer factors for carbon monoxide (TL,CO) below 80% pred, even after correction for the anaemia, indicating parenchymal disease. Eight of these 12 patients had alveolocapillary membrane defect, as demonstrated by a gas transfer factor of the pulmonary membrane (Tm) less than 80% pred. Mean resting arterial oxygen saturation was 95 +/- 2 (range 92-98) %. Eleven patients had oxygen desaturation of 5% or more during exercise on a bicycle ergometer, consistent with interstitial lung disease. There was no clinical or echocardiographic evidence of heart failure. Percentage predicted TLC was inversely correlated with age (r = -0.547; p = 0.043). Both percentage predicted TLC and TL,CO were not correlated with iron burden or desferoxamine ratio. High resolution CT in the three selected patients showed no evidence of pulmonary fibrosis. We conclude that thalassaemia major patients have a predominant restrictive lung dysfunction with pulmonary parenchymal disease and alveolocapillary membrane block. The restrictive and interstitial lung disease could not be accounted for by iron loading or pulmonary fibrosis in our patients.
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PMID:Lungs in thalassaemia major patients receiving regular transfusion. 883 48

Lung function abnormalities in thalassaemia major are various and complex; however, patients still die from cardiac lesions. This study aimed to investigate pulmonary and cardiac involvement at an early stage in thalassaemic patients and study their respective implications at rest and during exercise. Ten patients (five adults and five children) with thalassaemia major were investigated by echocardiography, lung function and exercise testing a few days after transfusion. All have had regular transfusions and chelation with deferoxamine and none had chronic pulmonary disease symptoms. Minor lung function abnormalities were found: two patients had moderate obstructive syndrome and two had a decreased carbon monoxide transfer factor. Hypoxaemia was never found at rest and no desaturation was observed at the end of exercise. Echocardiographic abnormalities were also moderate. Peak oxygen consumption (V'O2) was decreased in three adults and was lower in adults than children (means 27.7+/-4.6 and 41.1+/-4.8 mL.kg(-1).min(-2) respectively). The V'O2/cardiac frequency slope was lower in adults than children (0.25+/-0.06 versus 0.42+/-0.10 mL.kg(-1).min(-2)), whereas end-exercise breathing reserve was >40% maximal voluntary ventilation for all patients. In conclusion, none of the patients had ventilatory limitations but older patients had cardiac limitations assessed by the relationship between oxygen consumption and cardiac frequency. Exercise testing may detect cardiac impairment in thalassaemia major earlier than investigations at rest.
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PMID:Lung function and exercise capacity in thalassaemia major. 986 9

Pulmonary dysfunction represents one of the least studied complications in thalassemic patients. Probably, it is due to the absence of pulmonary symptoms. There are few works in the literature, and contradictory results have been published. The aim of this study was to define the spirometric pattern and the possible causes of lung impairment by testing bronchoalveolar lavage (BAL) with pathological pulmonary function tests (PFTs). Furthermore, diffusion capacity tests for carbon monoxide corrected for hemoglobin value (Dco*) were performed. We studied 48 thalassemic patients (27 F and 21 M), with an age range from 8 to 23 years, divided into two groups on the basis of PFTs results. Thus, group A was formed by 16 patients with restrictive spirometric patterns of whom 14 had also reduced Dco* values and group B consisted of 32 patients with normal PFTs and Dco* values. Patients of group A underwent chest high-resolution computing tomography (CHRCT) and BAL whose fluid was analyzed by microbiologic and cytological assays. A pathological CHRCT picture was present in 8 patients. Nine out of 16 patients who accepted to undergo BAL had a chronological age greater than 17 years with a mean bone age of 13.9 years. BAL results showed lymphocyte alveolitis in 6 patients and a normal cytogram in 3, while alveolar iron-laden macrophages were present in 4 out of 6 patients with alveolitis and 2 out of 3 patients with normal cytogram. Moreover, all examined BAL fluids showed a normal CD4/CD8 ratio, while only 2 patients showed an altered serum CD4/CD8 ratio. We demonstrated the presence of (1) lung-restrictive syndrome in 16 of the oldest thalassemic patients; (2) lymphocyte alveolitis in 6 patients, and (3) a picture of interstitial fibrosis by CHRCT in 8 of them. All these data are suggestive of a diagnosis of interstitial lung disease secondary to thalassemia. BAL helped to identify the presence of alveolar iron-laden macrophages that represented a local defense mechanism against free iron. This latter finding therefore might be the primary cause of the lung impairment promoting an oxidative damage. Further studies are needed to investigate this hypothesis and therapeutical potentials.
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PMID:Evidence of lymphocyte alveolitis by bronchoalveolar lavage in thalassemic patients with pulmonary dysfunction. 1083 52


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