An Autopsy Case of β-Thalassemia Major Illuminating the Pathological Spectrum of the Disease

Despite declining rates worldwide, autopsy studies remain invaluable tools to expand existing knowledge on the pathophysiology of diseases, especially those with multisystem involvement. β-thalassemia major (β-TM) is a relatively common hemoglobinopathy in India and is characterized by a regular requirement for life-sustaining transfusions and chelation. The iron overload is an invariable side effect. This secondary hemosiderosis leads to several complications, primarily in the heart, liver, pancreas, and endocrine organs. Despite adequate transfusion and chelation, untransplanted patients may show early mortality for several reasons. We report a 10-year-old boy with β-TM who died with clinical possibilities of iron overload-related cardiac failure and pulmonary arterial hypertension. His autopsy revealed certain unique disease pathologies in the form of minimal cardiac fibrosis in the presence of significant cardiac siderosis and widespread endocrine damage due to iron-overload. A null-cell pituitary microadenoma, previously undescribed in thalassemia syndromes, was found. This report highlights the importance of the diminishing art of autopsy, without which these histopathological insights would not have emerged.

BCL11A Down-Regulation Induces γ-Globin in Human β-Thalassemia Major Erythroid Cells

Fetal hemoglobin (Hb F, α2γ2) is a potent genetic modifier of the severity of β-thalassemia (β-thal) and sickle cell anemia. Differences in the levels of HbF that persist into adulthood affect the severity of sickle cell disease and the β-thal syndromes. B-cell lymphoma 11 A (BCL11A) is a potent silencer of HbF. Here, we reactivated γ-globin expression by down-regulating BCL11A to alleviate anemia in the β-thal major (β-TM) patients. BCL11A were down-regulated by lentiviral RNAi (RNA interference) in the K562 cell line and an in vitro culture model of human erythropoiesis in which erythroblasts are derived from the normal donor mononuclear cells (MNC) or β-TM MNC. The expression of γ-globin were analyzed by qPCR (quantitative real-time polymerase chain reaction) and Western blot techniques. Our data showed that down-regulation of BCL11A induces γ-globin production in the K562 cell line and human erythrocytes from normal donors and β-TM donors, without altering erythroid maturation. This is the first report on γ-globin induction by down-regulation of BCL11A in human erythroblasts derived from β-TM.

A Case of Fatal Agranulocytosis That Developed in a Patient with β-Thalassemia Major Treated with Deferiprone

A 29-year-old male with transfusion-dependent β-thalassemia major (β-TM), splenectomized and on chelation therapy with deferiprone (DFP or L1) due to heart and liver hemosiderosis, presented with high fever and agranulocytosis. Deferiprone was discontinued and a broad spectrum antibiotic therapy was started intravenously. The patient remained febrile and showed no recovery of neutrophil count even after the initiation of granulocyte colony-stimulation factor (G-CSF). After 12 days at the hospital, he developed respiratory failure and was transferred to the intensive care unit (ICU) where he developed multi-organ failure and died 3 days later. To investigate the mechanism of agranulocytosis, bone marrow mononuclear cells of a healthy volunteer were plated on culture dishes, with or without the patient's serum. The observation of colony forming units of progenitor cells in dishes that contained the patient's serum, provided inconclusive explanation of the possible mechanism of DFP-induced agranulocytosis. This is a case of fatal agranulocytosis developing in a patient being treated with DFP, a well recognized but rare complication of this drug. Further studies are required in order to elucidate the possible pathogenic mechanism of agranulocytosis due to DFP and to provide clear guidelines in order to best care for the patient.

Interaction of an α-Globin Gene Triplication with β-Globin Gene Mutations in Iranian Patients with β-Thalassemia Intermedia

The 3.7 kb triplicated α-globin gene (ααα(anti 3.7)) mutation has been found in most populations. It results from an unequal crossover between misaligned homologous segments in the α-globin gene cluster during meiosis. The pathophysiology and clinical severity of β-thalassemia (β-thal) are associated with the degree of α chain imbalance. The excess of α-globin chains plays an important role in the pathophysiology of β-thal. When heterozygous/homozygous β-thal coexists with an α gene numerical alteration, the clinical and hematological phenotype of thalassemia could change to mild anemia in case of an α deletion (-α/αα) or severe anemia in the case of an α triplication (αα/ααα). The coexistence of an ααα(anti 3.7) triplication is considered an important factor in the severity of β-thal, exacerbating the phenotypic severity of β-thal by causing more globin chain imbalance. This study shows that the ααα(anti 3.7) triplication is an important factor in the causation of β-thal intermedia (β-TI) in heterozygous β-thal. This type of phenotype modification has rarely been observed and reported in the Iranian population. Here we report the coinheritance of a triplicated α-globin gene arrangement and heterozygous/homozygous β-thal in 23 cases, presenting with a β-TI or β-thal major (β-TM) phenotype. Some of these patients were considered to have a mild β-TI phenotype as they needed no blood transfusions; some occasionally received blood transfusions in their lifetime (for example on delivery) but some are dependent on regular blood transfusions (every 20 to 40 days). Our study was focused on the importance of detecting the α-globin gene triplication in genotype/phenotype prediction in Iranian thalassemia patients.