EXPRESS: Soluble Fms-Like Tyrosine Kinase-1 as an Endothelial Dysfunction Biomarker Associated with Pulmonary Hypertension in Adult Patients with Beta-Thalassemia Major

The etiology of vascular problems in beta-thalassemia has been linked to endothelial damage. Antiangiogenic proteins such as soluble fms-like tyrosine kinase-1 (sFLT-1) inhibit the signaling of vascular endothelial growth factor (VEGF) and placental growth factor (PIGF), resulting in a decrease in the development of new blood vessels. Additionally, they promote the maturation of existing blood vessels and lead to endothelial dysfunction. This study aimed to assess the role of sFLT-1 in adult patients with beta-thalassemia major (TM) as a biomarker of endothelial dysfunction and its association with pulmonary hypertension (PHT). A total of 90 subjects were recruited and categorized into two groups: 45 patients with beta-TM, who were further divided based on the presence or absence of PHT, and 45 healthy individuals served as a control group. Serum sFLT-1 was determined using the enzyme-linked immunosorbent assay (ELISA) technique. The results revealed that Beta-TM patients had higher sFLT-1 levels than the control group. In addition, patients with PHT had significantly higher sFLT-1 levels compared to those without PHT. The levels of sFLT-1 were positively correlated with von Willebrand factor (vWF), serum ferritin, and high-sensitivity C-reactive protein (hs-CRP). Regression analyses demonstrated a significant association between high sFLT-1 levels and the occurrence of PHT. Additionally, sFLT-1 (at a cutoff value of 8.84 pg/ml) demonstrated a sensitivity of 83.30% and specificity of 80.0% in diagnosing thalassemic patients with PHT. In conclusion, beta-TM patients with elevated serum levels of sFLT-1 are at risk of developing endothelial dysfunction and subsequent development of PHT.