No abstract

Background Identification of α0-thalassemia (SEA and THAI deletions) is essential in preventing and controlling of severe thalassemia diseases. We have developed the LAMP colorimetric assays for the detection of these two thalassemia defects and validated them in population screening and prenatal diagnosis. Methods Three LAMP colorimetric assays specific for α0-thalassemia (SEA deletion), α0-thalassemia (THAI deletion) and normal DNA sequence were developed. These assays were validated on 341 subjects who had initial thalassemia screening positive and various thalassemia genotypes. Prenatal diagnosis of α0-thalassemia (SEA deletion) was done on 33 fetuses at risk of having Hb Bart’s hydrops fetalis syndrome. Results The LAMP colorimetric assays for α0-thalassemia (SEA and THAI deletions) could be clearly interpreted by naked eyes. The assay for α0-thalassemia (SEA deletion) showed a 100% (62/62 x 100) sensitivity and 98.2% (274/279 x 100) specificity whereas, that of the α0-thalassemia (THAI deletion) showed 100% (1/1 x 100) sensitivity and 99.7% (339/340 x 100) specificity. We obtained a 100% concordant prenatal diagnosis results using LAMP assays of α0-thalassemia (SEA deletion) in 33 fetuses as compared to the conventional PCR analysis. Conclusions The LAMP colorimetric assays developed are simple, rapid, and do not require sophisticated equipment. Inclusion of the LAMP tests in the existing screening protocol significantly reduce the screening cost and the molecular analysis workload, which should prove useful in the prevention and control program of hemoglobinopathies in the region.

No abstract

Introduction: Extramedullary hematopoiesis (EMH) is one of the main complications in patients with thalassemia in compensation for the underlying ineffective erythropoiesis. This study aimed to evaluate the association between ineffective erythropoiesis biomarkers and EMH in patients with thalassemia. Methods: A cross-sectional study of thalassemia patients aged >18 years old at Srinagarind Hospital was performed. Phosphatidylserine-exposed red blood cells (PS-exposed RBCs) were studied by flow cytometry. The levels of growth differentiation factor-15 (GDF15) and soluble transferrin receptor (sTfR) levels were determined using ELISA. Results: One hundred and thirty-one patients were enrolled. EMH was found in 34 patients (26.0%). EMH was more prevalent among patients with β-thalassemia as compared to those with α-thalassemia (36.4% vs. 4.7%).  The levels of GDF15 and sTfR were different between the two groups and indicated a greater degree of ineffective erythropoiesis in β-thalassemia patients. The levels of PS-exposed RBCs showed a modest correlation with EMH. Advanced age and the PS-exposed RBC levels had a statistical significance associated with EMH. Conclusions: Advanced age and high PS-exposed RBC levels are associated with EMH in thalassemia. PS-exposed RBCs showed a modest correlation with EMH and may be used to predict the development of EMH in thalassemia.

Background: Thalassemia is a group of hereditary hemoglobinopathies caused by decreased or absent synthesis of α and/or β globin chains. Studies have shown that hypercoagulability and thrombosis are common clinical symptoms in β-thalassemia, especially β-thalassemia intermedia, but little is known about in α-thalassemia. This study aims to examine phosphatidylserine (PS) levels, platelet activation, and coagulation markers in splenectomized (S) and nonsplenectomy (NS) patients with hemoglobin (Hb) H disease. Methods: The NS group comprised 20 patients (median age 15.0 years, range, 14–16.5 years), and the S group consisted of 11 patients (median age 16.4 years, range, 14–19.9 years) with Hb H disease; the control group consisted of 20 normal subjects. Hematological parameters were collected. Flow cytometry was used to measure PS exposure on red blood cells. The levels of intercellular adhesive molecule (ICAM)-1, tumor necrosis factor α (TNFα), β-thromboglobulin (TG) and prothrombin fragment 1 + 2 (F1.2) were determined using ELISA test kits. Results: Significant increases in the levels of PS, ICAM-1, TNFα, β-TG, and F1.2 were observed in both patient groups compared to normal controls (p < 0.01). Conclusion: This observation indicates blood coagulation, endothelial injury, chronic low-grade inflammation, platelet activation, and thrombin generation are present in Hb H disease; these findings merit further assessment in a larger prospective cohort to establish possible links with thrombotic manifestations.