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 purpose of this study was to define the incidence of arterial calcifications in patients with beta-thalassemia. Beta-thalassemia patients have been shown to present a high prevalence of angioid streaks and skin lesions characteristic of pseudoxanthoma elasticum (PXE). Given the fact that vascular involvement in the form of arterial calcifications is also a common manifestation of PXE, the authors investigated radiographically the presence of arterial calcifications in beta-thalassemia patients. They studied 40 patients with beta-thalassemia over 30 years of age. Forty healthy, age- and sex-matched subjects were chosen as a control group. Radiographs of the tibias were performed in order to disclose arterial calcifications. The occurrence of PXE skin lesions and of angioid streaks (AS) was also investigated. Arterial calcifications were detected in the posterior tibial artery in 22 (55%) beta-thalassemia patients and in six (15%) controls (P < 0.01 for the comparison). PXE skin lesions and AS were found in eight (20%) and 21 (52%) patients respectively. A total of 34 patients (85%) had at least one of the three lesions, namely, arterial calcifications, angioid streaks, and/or PXE-like skin lesions. Stepwise logistic regression analysis did not reveal prognostic value in independent variables such as transfusions, chelation therapy, pseudoxanthoma elasticum skin lesions and/or angioid streaks, diabetes, hemoglobin, serum ferritin, and uric acid. It was concluded that arterial calcifications are common in older beta-thalassemia patients. This finding could be a manifestation of an acquired PXE syndrome associated with beta-thalassemia, and consequently, vascular events complicating PXE should be expected in these patients.
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PMID:Arterial calcifications in beta-thalassemia. 948 13

Thromboembolic (TE) events have been frequently reported in beta-thalassemic patients in association with known risk factors such as diabetes, complex cardiopulmonary abnormalities, hypothyroidism, liver function anomalies, and postsplenectomy thrombocytosis. In a recent survey involving 9 Italian thalassemic centers, we identified 32 patients with TE episodes in a total of 735 subjects, of whom 683 had thalassemia major and 52 thalassemia intermedia, corresponding to 3.95 and 9.61%, respectively. There was a great variation in localization: the main one (16/32) was CNS, with a clinical picture of headache, seizures and hemiparesis. Other localizations were the pulmonary (3 patients), mesenteric (1 patient) and portal (2 patients) sites. There were 6 cases of deep venous thrombosis (2 in the upper limbs, 4 in the lower ones). Intracardiac thrombosis was found in 2 subjects and clinical and laboratory signs of DIC were observed in 2 others during pregnancy. Since our patients with TE events present a statistically significantly higher incidence of associated dysfunction (cardiomyopathy, diabetes, liver function anomalies, hypothyroidism) than those without TE events (50 vs. 13.8%), we suggest close monitoring of those patients who are at higher risk of developing TE events because of the presence of one or more of these predisposing factors.
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PMID:Thromboembolic events in beta thalassemia major: an Italian multicenter study. 985 99

Long term effects of BMT in thalassemia were monitored in 33 patients transplanted between 1987 and 1995 and compared with 155 patients matched for age and treated during the same period with conventional therapy (CT). The incidence of fulminant sepsis and growth impairment was significantly higher in transplanted patients, whereas the occurrence of hypothyroidism, hypogonadism, and cardiopathy was higher in CT patients. For diabetes, liver disease, and severe infections, the differences were not statistically significant. After BMT we performed monthly erythrocytaferesis for iron removal in 23 (70%) patients, obtaining a complete normalization of iron stores in 91% of cases; among untreated patients, 60% had evidence of iron up to 8.3 years after BMT. Protection against poliovirus, tetanus, diphtheria, and hepatitis B has been lost in 74%, 47%, 78%, and 44%, respectively. After BMT a careful follow-up is needed to monitor and treat late transplant-related and thalassemia-related complications.
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PMID:Late effects of bone marrow transplantation for thalassemia. 966 51

Iron overload is the main cause of morbidity and mortality in patients with thalassaemia major. In order to establish if the presence of the mutations recently described in the haemochromatosis gene affects the severity of iron overload in thalassaemia patients, we compared the prevalence of mutations C282Y and H63D in 216 young adults regularly transfused and chelated in North-Eastern Italy with the frequency found in a group of blood donors from the same area. For each patient, mean serum ferritin over the last 3 years, liver iron concentration, and the presence of diabetes, hypogonadism and heart disease, were considered. The frequency of the C282Y allele was 1.9% in patients with thalassaemia major and 2.3% in blood donors (P=ns). The frequency of the H63D allele was 16.2% in patients with thalassaemia major and 15.3% in blood donors (P=ns). When age, liver iron concentration and mean yearly serum ferritin levels were compared in patients with and without mutations C282Y and H63D, no significant differences were found. Also, the prevalence of iron-induced complications was not significantly different between patients carrying or not carrying the mutations. The presence of the HH mutations does not seem to influence the degree of iron overload and its consequences in regularly transfused and chelated patients with thalassaemia major.
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PMID:The haemochromatosis mutations do not modify the clinical picture of thalassaemia major in patients regularly transfused and chelated. 985 37

Cooley's original description of beta-thalassaemia major included marked bone deformities as a characteristic feature. These were thought to be due to expansion of haemopoiesis attempting to compensate for the congenital anaemia. Regular blood transfusions from infancy prevents these skeletal problems. Nevertheless, symptoms due to bone disease frequently occur in adult patients. Osteoporosis has not previously been reported as a cause of severe morbidity in thalassaemia major. The present study shows a high prevalence of low bone mass among thalassaemia major patients and analyses the predisposing causes. Bone density scans were performed in 82 patients with transfusion-dependent beta thalassaemia. Factors known to be associated with low bone mass such as gender, endocrine disorders and lifestyle activities, together with factors specific to the thalassaemia and its management, were included in a series of univariate analyses to ascertain any significant associations. 42 (51%) of the patients had severely low bone mass and a further 37 (45%) had low bone mass. The three factors showing a statistically significant association with severely low bone mass were male sex, 24/38 (63%) males had severely low bone mass, compared with 18/44 (41%) females, the lack of spontaneous puberty, 22/32 (69%) who required therapeutic induction of pubertal development had severely low bone mass, compared with 19/47 (40%) with spontaneous puberty and diabetes, 8/10 (80%) diabetic patients had severely low bone mass, compared with 23/56 (41%) with normal glucose tolerance. There was no association between the bone mineral density measurements and the haematological characteristics or treatment details of these patients. Severely low and low bone mass are common findings in patients with beta-thalassaemia major despite optimal transfusion and iron chelation. The associated features suggest that the severely low bone mass is due to endocrine abnormalities, in contrast to the haematological causes of bone disease characteristically seen in untreated thalassaemics.
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PMID:High prevalence of low bone mass in thalassaemia major. 988

We have previously shown a high incidence of osteopenia and osteoporosis in patients with thalassaemia major. These bone changes, were more severe in males than females, in those with diabetes mellitus and with hypogonadal-hypogonadism. Our recent studies concern the relationship of erythroid activity, assessed by serum transferrin receptors as an overall measure of anaemia, to osteoporosis. Serum transferrin receptor levels correlated with the mean pre-transfusion haemoglobin level, but there was no correlation with the incidence of osteopenia and osteoporosis. As osteoporosis has a strong genetic component we have also studied the COLIA1 and COLIA2 genes which code for the major protein of bone (type 1 collagen). Studies by others have shown in non-thalassaemic patients that a polymorphism G-->T or TT in a regulatory region of COLIA1 at the recognition site for transcription factor Sp1 is associated with the presence of osteoporosis. Our studies suggest that Sp1 polymorphism is not specific to any one ethnic group; the polymorphism occurs more commonly in females (female to male ratio 2:1). In male thalassaemia major patients the presence of the Sp1 mutation was associated with more severe osteoporosis of the spine and the hip compared with female patients. There is failure of improvement in spinal osteoporosis with bisphosphonate therapy (intravenous Pamidronate) in male patients with the Sp1 mutation.
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PMID:Genetic and acquired predisposing factors and treatment of osteoporosis in thalassaemia major. 1009 Nov 49

Glyco-metabolic status was evaluated in 29 pubertal homozygous thalassaemics aged from 17 to 42 years and in 12 age-matched healthy subjects. Diagnosis of diabetes mellitus was assessed in 4 patients (13.8%), who became diabetic after the age of 18 years. With respect to controls non-diabetic patients exhibited significantly higher fasting plasma glucose levels and more sustained glycemic responses to oral glucose tolerance test, whereas their overall insulin output was significantly lower. Moreover non-diabetic thalassaemic patients showed a clear reduction of both beta-cell function and insulin resistance indices (HOMA model). In conclusion our data show a high prevalence of diabetes but do not support the existence of an insulin resistant status in thalassaemia major, at least in adulthood.
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PMID:Glucose tolerance, insulin secretion and peripheral sensitivity in thalassaemia major. 1009 Nov 58

The incidence and prevalence of insulin-dependent diabetes mellitus (IDDM) and impaired glucose tolerance (IGT) were studied in a series of 273 patients with thalassaemia major followed in Ferrara from 1954 to 1998. It was found that the prevalence of glucose metabolism abnormalities has decreased and that the mean age of diagnosis has increased over the years. Risk factors associated with IDDM and IGT were lack of compliance with chelation therapy, iron overload and the presence of cirrhosis and severe fibrosis.
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PMID:Epidemiology and chelation therapy effects on glucose homeostasis in thalassaemic patients. 1009 Nov 59

Specific laboratory and clinical characteristics indicate that the pathogenesis of diabetes in patients with thalassemia resembles the pathogenesis of maturity-onset diabetes (type II). Thus oral hypoglycemic agents may be used to regulate blood glucose levels by induction of insulin secretion and reduction of insulin resistance. The efficacy of glibenclamide administration in the management of glucose disturbances was evaluated in 33 patients with thalassemia, aged 12-30 years (mean 17.4 +/- 3.7), in whom diet and exercise failed to regulate hyperglycemia. The results were compared to 30 thalassemic patients (mean age 18.4 +/- 4.8 yr), who followed only diet and exercise. Improvement of OGTT was observed in 73% of the treated patients versus 43% of the control group for a mean period of 59 months. Deterioration of OGTT occurred more rapidly (33.7 +/- 26.1 vs 40.7 +/- 34.5 mos), and in more patients of the untreated group (57%) than in treated patients (27%). Among treated patients, effectiveness of oral hypoglycemic agents lasted longer in patients with diabetic (64.1 +/- 40.3 mos) than in patients with impaired curves (54.2 +/- 31 mos).
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PMID:Glucose disturbances and regulation with glibenclamide in thalassemia. 1009 Nov 60

Thalassaemic patients with diabetes mellitus are at risk of developing retinopathy. To evaluate the prevalence and the characteristics of diabetic retinopathy in thalassaemics we examined 46 patients with beta-thalassaemia major and insulin-dependent diabetes by fluorescein angiography. The study group was matched for sex, age and diabetes duration with a control group of 46 type 1 diabetic patients. Diabetic retinopathy was detected in 26% (12/46) of thalassaemics and in 50% (23/46) of the controls. In thalassaemics the diabetic retinopathy was significantly less severe than in controls (P < 0.0001). The influence of risk factors for diabetic retinopathy (duration of diabetes and metabolic control) was confirmed in the control group. In thalassaemic patients we found no significant correlation between these risk variables and the presence of diabetic retinopathy. Various factors may protect thalassaemics from diabetic retinopathy: heterogeneity of pancreatic functions; high incidence of hypogonadism; contemporary dysfunction of GH and/or glucagon secretion.
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PMID:Prevalence of retinopathy in diabetic thalassaemic patients. 1009 Nov 61


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