Extramedullary hematopoiesis-related pleural effusion: the case of beta-thalassemia.

BACKGROUND: Thalassemia intermedia has a later clinical onset and a milder anemia than thalassemia major, characterized by high output state, left ventricle remodeling, and age-related pulmonary hypertension. Bone deformities, extramedullary hematopoiesis (EMH), and spleen and liver enlargement are the consequences of hypoxia and enhanced erythropoiesis. The EMH-related pleural effusion is rarely referred to in the literature of thalassemia. METHODS: We reviewed the thalassemia patients' medical records hospitalized for pleural effusion in our Department, within the last 6 years. RESULTS: Eight (4 men) thalassemia intermedia patients admitted for symptomatic pleural effusion were identified. Common clinical findings on admission were dyspnea and apyrexia. Their mean hemoglobin level was 7.15 +/- 0.64 g/dL. Radiology revealed intrathoracic EMH and pleural effusion in all patients: exudative in seven patients and massive hemothorax in one. Cytologic fluid analysis was negative for malignancy. Fluid and serum cultures, antibodies, and stains were negative for viral, bacterial, and fungal infection. The hemothorax case was successfully treated with repeated aspirations, transfusions, and hydroxyurea. Although repeated thoracentesis and radiation could not control the effusions in the rest of the cases, pleurodesis was successful in 5 patients, without serious adverse events. Treatment was further accomplished with hydroxyurea. No relapses were observed in the mean 30 month follow-up period. CONCLUSIONS: Afebrile, EMH-related pleuritis represents a potentially life-threatening complication in thalassemia. Therapy should be individualized and treatment is emerging. Pleurodesis seems to be an effective and safe therapeutic option for exudative effusions, while transfusion-chelation therapy combined with hydroxyurea may be helpful in suppressing increased erythropoiesis.

Does heterozygous beta-thalassemia confer a protection against coronary artery disease?

Six hundred and thirty-eight patients who presented with clinical symptoms and/or electrocardiographic findings suggestive of stable angina pectoris were studied; they were also investigated by coronary arteriography. Hemoglobin electrophoresis was performed on all patients to detect the presence of the beta-thalassemia trait. Results were analyzed by logistic regression analysis to determine whether the latter confers any protective effect against advanced coronary artery disease (aCAD; defined as the presence of atheromas in coronary arteries, resulting in stenosis at least 70%). The role of the currently accepted risk factors (smoking, hypertension, hypercholesterolemia, and diabetes) in developing aCAD were reconfirmed, while at the same time it was found that beta-thalassemia heterozygosity is associated with a reduced risk against aCAD (odds ratio 0.39, 95% confidence interval 0.16-0.98). The lipoprotein and blood rheology profile of these individuals may be the underlying causes of this protective effect.

Hemothorax due to extramedullary erythropoietic masses.

We describe a 27-year-old male patient suffering from beta-thalassemia intermedia who presented with a nontraumatic spontaneous hemothorax due to extramedullary hemopoietic foci. In reviewing the literature, four similar reports were found. The details of this unusual entity are discussed.

Decreased expression of membrane alpha4beta1, alpha5beta1 integrins and transferrin receptor on erythroblasts in splenectomized patients with beta-thalassemia intermedia. Parallel assessment of serum soluble transferrin receptors levels.

Dysfunction of cell membrane is a recognized consequence of the pathogenetic process underlying the beta-thalassemia syndromes and it is reasonable to hypothesize that surface structures crucial for the development of erythroid lineage may also be affected. The study included six adult splenectomized patients with beta-thalassemia intermedia. Expression of alpha4beta1 integrin (CD49d/CD29), alpha5beta1 integrin (CD49e/CD29) and transferrin receptor (CD71) on peripheral blood and bone marrow erythroblasts and on erythroid precursors grown in vitro was studied by flow cytometry and immunocytochemistry. Serum soluble transferrin receptor levels (sCD71) were also measured with enzyme-linked immunosorbent assay. In beta-thalassemic patients, significant reduction of CD49d, CD29 and CD71 expression was found in peripheral blood nucleated red cells, compared to patients presenting with erythroblasts in the circulation because of other diseases. Marrow erythroblasts were also deficient for the same molecules against the erythroblasts in iron deficiency anemia. All molecules tested were greatly diminished on erythroid precursors developed in vitro from the patients' cells. Serum sCD71 levels were much higher in thalassemic patients in comparison to both patients with iron deficiency anemia and healthy individuals. The loss of certain integrins and CD71 from erythroid precursors in beta-thalassemia intermedia could be attributed to a generalized membrane dysfunction, perhaps affecting the integrity of their transmembrane domains. The elevation of serum sCD71 levels may be the result of the increased red cell lineage turnover or, alternatively, may indicate increased shedding from the cells to prevent iron overload. In any case, further molecular study of the membrane components is warranted to provide a better understanding of the pathogenetic process in beta-thalassemia syndromes.

Suboptimal erythropoietic response to hypoxemia in idiopathic pulmonary fibrosis.

BACKGROUND AND STUDY OBJECTIVES: Idiopathic pulmonary fibrosis (IPF) is a chronic inflammatory process characterized by severe derangement of gas exchange in the advanced stages of disease. However, erythrocytosis is infrequent in IPF. The aim of this study was to investigate the potential relation between the blunted erythropoietic response and the chronic inflammation. SUBJECTS: Nine patients (6 men and 3 women) with IPF and profound hypoxemia (PO(2) < 65 mm Hg) and 34 sex- and age-matched healthy volunteers participated in the study. METHODS: We evaluated the hematologic parameters, serum erythropoietin, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-8 levels. We also studied the development of burst-forming unit-erythroid (BFU-E)-derived colonies in semisolid methylcellulose cultures in blood samples from all patients. RESULTS: Hemoglobin and serum erythropoietin levels were almost comparable between the two studied groups. On the contrary, serum TNF-alpha, IL-6, and IL-8 values were significantly higher in patients with IPF (p < 0.05, p < 0.01, and p < 0.001, respectively). IPF sera induced a significant growth inhibition of erythroid bursts arising from mononuclear cells of either patients or control subjects compared with heat-inactivated AB serum (p < 0.05 and p < 0.01, respectively). Moreover, there was an apparent increment in the number of BFU-E colonies when patients' mononuclear cells were cultured in comparison with those of healthy subjects (p < 0.05). CONCLUSIONS: Our findings suggest that in IPF there is an increased number of primitive erythroid progenitors, which fail to proliferate and differentiate in vivo, suggesting a kind of ineffective erythropoiesis. As a consequence, hemoglobin levels do not rise in proportion to the severity of hypoxemia. Cytokines released from alveolar macrophages seem to have not only local but also systemic effects, since the serum of these patients directly suppressed erythropoiesis; however, the suboptimal erythropoietic response to hypoxia cannot be entirely attributed to this suppression. It is possible that several other factors interfere, synergistically or additively.