Cardiac involvement in beta-thalassemia major and beta-thalassemia intermedia

The forms and severity of cardiac complications were investigated in patients with asymptomatic thalassemia intermedia and thalassemia major by M-mode, bi-dimensional echocardiography (ECHO) and echo-Doppler. Twenty-eight patients of both sexes with beta-thalassemia intermedia (beta-TI), mean age 23.2 +/- 6.3 years, untransfused or minimally transfused, were compared to 42 age- and sex-matched subjects with thalassemia major, who were regularly treated with hemotransfusive therapy [pre-transfusion hemoglobin (Hb) values 9.5 +/- 0.9 g/dL] and iron chelation. All patients were splenectomized. Age and sex matched healthy control subjects were randomly selected. beta-Thalassemia major (beta-TM) patients showed a marked reduction in contractile state and a milder left ventricular (LV) enlargement than beta-TI patients. Cardiac output (CO) and cardiac index (CI) were increased in both groups of patients but appeared significantly higher in beta-TI patients with consequent altered LV diastolic function indices. In addition, beta-TI patients had reduced indices of pulmonary artery flow related to long-term chronic anemia rather than iron overload. The progressive rise in CO and CI casts doubts on the current management of beta-TI syndromes.     

Cardiopulmonary assessment in beta-thalassemia major

Thalassemia patients succumb at a young age to congestive heart failure. Hitherto, attention has been focused on left ventricular function. This report emphasizes right ventricular dysfunction and abnormal pulmonary function. We performed cardiopulmonary evaluation, including echo-Doppler, spirometry, CO diffusion (DCO), and blood gas analyses in 35 patients with homozygous beta-thalassemia maintained by multiple blood transfusions. Six autopsy lung specimens were studied. Thalassemia patients exhibited pulmonary dysfunction, characterized by hypoxemia (85 percent of the patients were outside the 95 percent confidence limits), reduced lung volumes (51 percent), flow rates (63 percent) and DCO (50 percent). Right ventricular dysfunction was more prevalent than left ventricular dysfunction. Furthermore, 75 percent of the patients had evidence of pulmonary hypertension consistent with more frequent right ventricular rather than left ventricular dysfunction. Our findings suggest that in thalassemia patients, complex cardiopulmonary abnormalities precede the final outcome of congestive heart failure.     

Non-Hodgkin disease in beta-thalassemia major

Thalassemia is a spectrum of diseases characterized by the decrease or absence of globin chains. The occurrence of lymphoma in thalassemia has rarely been reported, and our review of the English literature revealed only four cases. Because anemia is always masked by regular transfusions in thalassemic patients, physicians discover a hidden malignancy late in the course of the disease. We hereby report the case of a thalassemic patient developing non-Hodgkin disease and discuss the possibility of a link between the two disease entities. This case is intended to alert physicians of the possibility of a malignancy in thalassemia patients.     

Abnormal assembly of membrane proteins in erythroid progenitors of patients with beta-thalassemia major

The life threatening anemia in beta-thalassemia major (Cooley's anemia) is characterized by profound intramedullary lysis, the cause of which is incompletely understood. Using marrow obtained from beta thalassemia major patients undergoing allogeneic bone marrow transplantation in Pesaro Italy, it became possible to directly study the mechanism of the intramedullary hemolysis. Based on our previous studies, we hypothesized that the unmatched alpha globin chains would interfere with normal assembly of erythroid precursor membrane proteins. Patient and control erythroid precursors were reacted with monospecific polyclonal rabbit antibodies directed against spectrin, band 3, and band 4.1 and with a monoclonal anti-alpha globin chain antibody. Using laser confocal fluorescence microscopy, normal erythroid precursors show no alpha globin chain accumulation and exhibited uniformly smooth rim fluorescence of the three membrane proteins. In some thalassemic precursors, spectrin appeared to interact with large alpha globin accumulations, and in many of these cells the spectin appeared clumped and discontinuous. Band 4.1 interacted strongly with accumulations of alpha globin in thalassemic precursors to produce bizarrely clumped zones of abnormal band 4.1 distribution. Band 3 was incorporated smoothly into thalassemic erythroblast membranes. However, the proerythroblasts and basophilic erythroblasts were significantly deficient in band 3. Thus, accumulations of alpha globin in beta- thalassemia major colocalized with and disrupt band 4.1 and spectrin assembly into the membrane. The cause of deficient band 3 incorporation into thalassemic proerythroblast membranes remains unknown. These profound membrane alterations would likely contribute to the intramedullary lysis seen in Cooley's anemia.     

Reticuloendothelial phagocytic function in children with beta-thalassemia major.

Reticuloendothelial phagocytic capacity (REPC) was determined in 14 children with beta-thalassemia major, by means of technetium 99m sulfur colloid uptake, who had not had splenectomy. No difference was observed in the REPC between patient and controls. The REPC of liver and spleen were evaluated separately by determining the half-time for the clearance of 99mTc from the blood. The REPC of both liver and spleen in patients was expected to be decreased when compared with controls; however, we found that the REPC of the liver was increased in patients and that there was no difference between patients' and controls' spleen values. This suggests that chronic anemia and hemosiderosis do not alter the REPC in beta-thalassemia major.     

Lipid peroxidation in rats chronically fed ethanol.

Chronic alcohol consumption induces cytochrome P450IIE1, enabling habitual abusers to consume far greater quantities of alcohol than normal subjects. This pathway of metabolism leads to the production of free radical species, which cause tissue damage through peroxidation of cell membranes. Groups of Wistar rats of equal male: female ratio (n = 24) were fed alcohol by gavage twice daily to achieve a dosage of 15 g/kg body weight. Mean peak blood alcohol concentrations of 186 mg% were produced in males and 156 mg% in females. The animals were allowed free access to standard laboratory chow and water. Control animals were pair-fed to the alcoholic group and fed isocaloric glucose by gavage. Groups of animals were killed between 9 and 11 am on consecutive mornings, after nocturnal feeding, since it has previously been shown that fasting rapidly depletes hepatic glutathione concentrations. Hepatic glutathione was measured by a spectrophotometric enzymatic recycling procedure. As a marker of lipid peroxidation hepatic malonaldehyde (MDA) was measured by high performance liquid chromatography. Hepatic MDA was increased in the alcoholic group (p < 0.001), as was total hepatic glutathione (p < 0.0001). Plasma concentrations of alpha-tocopherol were increased in the alcoholic group, but ascorbic acid and superoxide dismutase values were not affected. No sex differences were detected. The increased MDA production in the alcohol group is strong evidence that lipid peroxidation is a mechanism of alcoholic tissue damage. The rise in hepatic glutathione may be an adaptive response to free radical production that protects the rat against tissue damage.     

Lipid peroxidation in mouse models of atherosclerosis.

Over the past decade, oxidative modification of low-density lipoprotein (LDL) has been implicated in atherogenesis. This hypothesis has been supported indirectly by a number of in vitro and ex-vivo observations demonstrating the pro-atherogenic properties of oxidized LDL, their occurrence in atherosclerotic lesions and some positive results in animal studies with antioxidants. Only recently, however, have small mammalian models (mouse) of atherosclerosis been created by gene manipulation and widely used by investigators to better elucidate this pathogenetic aspect of such a complex disease. Transgenic animal models combined with the availability of more reliable, specific and sensitive markers of in vivo lipid peroxidation have now provided consistent evidence for a direct and functional role of oxidant stress in atherogenesis. The identification of yet unknown initiating event(s) of in vivo oxidant stress will be the challenge for the future. This should finally provide the basis for the development of most effective antioxidant agents that could modulate atherogenesis.     

Clinical management of beta-thalassemia major

Management of patients with beta-thalassemia is based on adequate, safe blood transfusions (free of transfusion-transmitted diseases) and prevention of iron overload. Iron overload causes multiple endocrinopathies, contributes to osteoporosis, and is the cause of cardiac disease. Cardiac disease, secondary to iron damage, causes death in developed countries as a result of noncompliance to deferoxamine from the third decade of life. In underdeveloped countries, cardiac death starts from 12 years of age, due to nonavailability of deferoxamine. With the emergence of the advanced cardiac magnetic resonance imaging technique, early diagnosis of heart iron will allow the currently available iron-chelating agents (oral and parenteral) to be used in an innovative way to improve the quality of life and improve survival of patients with beta-thalassemia.     

Bone marrow transplantation in beta-thalassemia major. The Israeli experience

The present report summarizes our experience in applying a new approach in bone marrow transplantation for the treatment of beta-thalassemia major. Ex-vivo pretransplant T-lymphocyte depletion with CAMPATH-1 was used for prevention of acute and chronic graft versus host disease and total lymphoid irradiation was added for the conditioning regimen for abrogation of potential rejection of T-cell depleted marrow allografts. Ten patients with homozygous beta-thalassemia major were 9-48 months of age (median 18.5 months) and received HLA-identical allogeneic T-cell depleted marrow after treatment with total lymphoid irradiation, busulfan and cyclophosphamide. Seven patients are alive and free of disease, 3-46 months post-transplantation. The actuarial probability of survival and of disease-free survival at two years was 70%. Three patients died: one of intracranial hemorrhage post-transplantation, one from busulfan interstitial pneumonitis, and one who rejected the first graft and developed fatal chronic graft versus host disease after a second transplant. Seven patients are alive and well with follow-up of 3-45 months, with no signs of acute or chronic GVHD. We conclude that T-cell depleted bone marrow transplantation is indicated for homozygous transfusion dependent young patients with beta-thalassemia who are minimally transfused, particularly in areas where optimal conventional therapy is not feasible.     

Lipid peroxidation and the major factors of its activation in patients with myocardial infarction

A dynamic study of 97 patients with primary macrofocal myocardial infarction (MI) has demonstrated that activated lipid peroxidation (LPO) is an important pathogenetic element of MI, with LPO level reflecting major stages of the disease and its complications. In acute MI, LPO activation depends on the magnitude of the stress syndrome and the severity of arterial hypoxia and is mediated by gas exchange disorders in the pulmonary circulation network. The passage of LPO products from ischemized myocardium to systemic circulation is also of significance. In the scarring phase, LPO activation is due to circulatory hypoxia associated with reduced cardiac contractility. The markedness of leucocytic response is an important factor of MI-associated LPO activation. The extent of LPO disorders is largely limited by the antioxidant system of the body.     

Pulmonary hypertension in patient with beta-thalassemia major

We report a case of pulmonary hypertension (PH) in a 35-year old patient with beta-thalassemia major; he had commenced blood transfusions after the age of 4 years and had been splenectomised at the age of 6 years. PH clinical presentation was not uncommon. Hemodynamic study revealed precapillary PH with high cardiac output; vasodilators agents led to significant pulmonary responsiveness. In beta-thalassemia, whereas congestive heart failure is common and due to cardiac hemosiderin deposition, PH appears to be non rare but its etiopathogenic mechanism remain unclear and probably non univoqual. Hypoxemia as well as hemodynamic changes related to chronic anemia including increased pulmonary flow might play an important role. Management should include blood transfusions to correct anemia, the indication and the choice of vasodilator agents need to be evaluated.     

Complications of beta-thalassemia major in North America

Treatment of patients with beta-thalassemia major has improved dramatically during the past 40 years; however, the current clinical status of these patients remains poorly characterized. We performed a cross-sectional study of 342 patients in the Registry of the National Institutes of Health-sponsored Thalassemia Clinical Research Network. Evidence of hepatitis C exposure was present in 35% of tested patients, was associated with age, and had a rate of spontaneous viral clearance of 33%. Ferritin levels ranged from 147 to 11 010 ng/mL (median, 1696 ng/mL). Median hepatic iron content was 7.8 mg/g dry weight and 23% of patients had values of 15 mg/g dry weight or higher. No patients 15 years or younger and 5% of patients aged 16 to 24 years had heart disease requiring medication. Ten percent had cirrhosis on biopsy. Endocrinologic complications were common among adults. Seventy-four (22%) patients had recent implantable central venous access devices (CVADs) placed. Among 80 episodes of bacteremia in 38 patients, 90% were attributable to the CVAD. Among 330 patients who had received deferoxamine chelation therapy, 224 (68%) reported no complications. We conclude that hepatitis C, iron-related organ dysfunction, and complications of iron chelation therapy are strongly age-dependent in North American patients with beta-thalassemia.     

Polyneuropathy and myopathy in beta-thalassemia major patients

The thalassemias are the most common single gene disorder in the world. Nowadays, the average life expectancy of patients in developed countries has increased significantly, while, there was an increase of complications. We aimed to investigate peripheral neuropathy and myopathy in this patient group using a neurophysiological study. We performed nerve conduction studies and electromyography of upper and lower extremities on 36 beta-thalassemia major (β-thal) patients. The electrophysiological findings were correlated with demographic data and laboratory parameters of the disease. Patients with β-thal present polyneuropathy or myopathy at (50%). Polyneuropathy was detected in (38.9%) and myopathy in (27.8%), while polyneuropathy and myopathy were present at (16.7%) with an overlap of the diseases in 1/3 of the patients. There was not a statistically significant correlation of polyneuropathy and myopathy with age, sex, splenectomy, nor with respect to laboratory parameters, hemoglobin, and ferritin. However, there was a statistically significant correlation of polyneuropathy and myopathy with iron overload, as recorded by the magnetic resonance imaging (MRI) of the heart and the liver. Our findings suggest that iron overload plays a key role in the pathogenesis of polyneuropathy and myopathy in β-thal patients, and performing heart and liver MRI for the prediction of such lesions in an annual basis is warranted.     

Hypoparathyroidism in beta-thalassemia major. Clinical and laboratory observations in 24 patients.

In the last 18 years, we have observed 24 cases of hypoparathyroidism (HPT) in beta-thalassemia major. At present, 4.5% of patients followed regularly in our department have this complication. HPT is thought to be mainly the consequence of iron deposition in the parathyroid glands. The age of our patients when HPT was diagnosed ranged from 11 to 24 years (mean 16.5 years). Their serum ferritin levels ranged from 810 to 15,200 ng/ml (mean 3,772 ng/ml). The severity of HPT varied widely. In only 3 patients was hypocalcemia severe with signs of tetany, seizures or cardiac failure. The onset of HPT was preceded or followed in most patients by other endocrine and/or cardiac complications. We found no clear relationship between HPT and serum ferritin levels in our patients, suggesting either an individual sensitivity to iron toxicity or early damage of the parathyroid gland before chelation had reduced the iron overload. However, the diagnosis of no new cases of HPT in the last 3 years coinciding with the much improved regime of chelation therapy suggests that chelation may have helped to prevent the development of HPT.     

Lipid peroxidation in human red cells

In this review we have discussed the chemistry and biochemistry of lipid peroxidation as well as lipid repair mechanisms in human RBCs. We have presented findings relating to the effect of lipid peroxidation on the RBC membrane and on several properties that are determinants of RBC survival in vivo. Since we have not discussed how oxidative damage to membrane proteins or hemoglobin may affect RBC survival, the role of lipid oxidation must be considered in a broader perspective. Considerable evidence has recently been reported to indicate that oxidative hemoglobin denaturation plays an extremely important role in RBC survival. Since all cellular components are susceptible to peroxidative damage, it is likely that multiple reactions will be important with regard to RBC oxidant injury, just as they have been implicated in many degenerative processes, and that certain "compartments" of the membrane may be more susceptible than others due to congenital or acquired defects in membrane structure.     

Erythrocyte membrane skeleton abnormalities in severe beta-thalassemia

The protein composition of ghosts, inside-out vesicles (IOV), and membrane skeletons (MS) of erythrocytes (RBC) from splenectomized (spx) and nonsplenectomized (non-spx) patients with beta-thalassemia major and beta-thalassemia intermedia was determined. Ghosts from spx thalassemia intermedia patients had a significant increase in their globin content (which was mostly heme reactive) and contained extra polypeptides in the protein 4.2 to 5 and 6-globin areas. The Triton- extracted MS from all of the thalassemic patients showed two major abnormalities: they retained up to twice the amount of protein 3 when compared with controls; they had a significant increase in their globin content, the concentration of which was independent of their protein 3 content. Analysis of the IOV revealed no differences between those prepared from normal controls and those of the patients. MS from spx thalassemia intermedia patients were grossly abnormal when examined by scanning electron microscopy and they exhibited aggregates of material that on transmission electron microscopy suggested the presence of globin precipitates. We propose that, although the integral protein composition, as reflected in the IOV, from severely affected beta- thalassemics is intact, their MS assembly is deranged. The altered skeletal structure of thalassemic RBC could result from attachment of denatured globin to the skeleton components. These abnormalities may contribute to the premature cell death seen in severe beta-thalassemia.     

Pulmonary function tests in children with beta-thalassemia major

Lung function abnormality is a known complication of thalassemia, but the results of studies in pulmonary function have been inconsistent. This study was conducted to describe the type of lung impairment in thalassemic children. Pulmonary function tests were conducted in 40 children with beta-thalassemia major, 23 males and 17 females. Tests included spirometry, total lung capacity (TLC), single breath diffusing capacity of the lung for carbon monoxide (DL(CO)) and arterial blood gases. Serum ferritin level was measured in all children to study its relationship to lung function impairment. A predominantly restrictive pattern was seen in 14 patients (35%). These patients had a significant reduction in RV, FVC, TLC and PEF with an FEV1/FVC ratio of more than 75%. Obstructive airway disease was found in six patients (15%), with an FEV1/FVC ratio less than 75%, increased RV and reduced FEF(25%-75%). Impairment of diffusion was found in 10 patients (25%), with DL(CO) reduced to less than 80% of the predicted value. Arterial blood gases results showed that no patient was hypoxic. No correlation was found between the severity of restrictive or obstructive disease and the serum ferritin level. There was a significant linear correlation between age and serum ferritin level (P < 0.019). Patients with thalassemia have a predominantly restrictive lung dysfunction pattern. This may be due to pulmonary parenchymal pathology, although the reason for the obstructive pattern seen in a small proportion of patients remains obscure.     

Cerebrovascular accident in beta-thalassemia major (beta-TM) and beta-thalassemia intermedia (beta-TI)

Chronic hypercoagulable state expressed clinically by thromboembolic events has been described in thalassemia. One of the affected organs is the brain where symptomatic and asymptomatic damage has been reported. The present report describes seven cases who presented with the signs of cerebrovascular accident (CVA), five ischemic and two with hemorrhage. Two of them died. All patients were splenectomized, five received regular blood transfusions, and their ferritin levels were between 1,200 and 3,000 mg %. In addition, four patients had congestive heart failure and atrial fibrillation, and three had "Bronze diabetes," The recommendation on the basis of the results is that well-designed clinical trials are indicated to monitor asymptomatic brain damage by magnetic resonance imaging in splenectomized patients over the age of 20 years, who are not regularly transfused and have a high risk to develop thromboembolic events. In this subset of patients, anticoagulant and/or antiplatelet therapy should be considered. Moreover, treatment of additional complications resulting from iron overload, which may contribute to the etiology of CVA such as cardiac failure and arrhythmia with or without "bronze diabetes," is mandatory.     

Plasma lipids and lipoproteins pattern in beta-thalassemia major

We studied serum lipids and lipoproteins in 20 patients with beta-thalassemia major, under high transfusion programme and regular chelation therapy, and in 20 control subjects. Total cholesterol, HDL-cholesterol, HDL2-and HDL3-cholesterol, apolipoprotein A and B levels were significantly lower in patients with Cooley's anemia, whereas free cholesterol, triglycerides and the HDL-/HDL3-cholesterol ratio did not differ in the two groups. We think that liver damage plays an important role in determining the altered lipoprotein pattern in beta-thalassemia major. However, other factors may contribute to cause such lipid changes.