Uso da dopplerfluxometria arterial renal, periférica e orbital em jovens portadores de anemia falciforme : associação com biomarcadores de hemólise

• Autor(a) principal: Ferrão, Thiago de Oliveira
• Data de Publicação: 2015
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/3606
• topic: Anemia falciforme; Ultrassonografia Doppler de Pulso; Rim; Extremidade inferior; Órbita; Hemólise; Marcadores biológicos; Anemia; Ultrasonography; Kidney; Lower Extremity; Orbit; Hemolysis; Biological markers; Sickle cell; Doppler; Pulsed; CNPQ::CIENCIAS DA SAUDE

Sickle cell anemia (SCA), homozygous form of sickle cell disease, is the most common hereditary hemoglobinopathy, characterized by the production of abnormal hemoglobin (HbS) which, in deoxygenated state, deforms and hardens the red cells with multisystemic manifestations. The clinical complications can be grouped in two subphenotypes: vasculopathy and viscosity-vaso-occlusion. Vasculopathy is associated to hemolysis intensity and contributes to chronic dysfunction of several organs, with endothelial participation. Endothelial dysfunction is associated to hemolysis laboratory markers (hemoglobin level, reticulocyte count, lactate dehydrogenase and bilirubin levels) and can manifest as abnormal vascular reactivity in visceral, peripheral and central blood flow studies, assessed by Doppler ultrasound. The aim of this study was to investigate the arterial vascular resistance state in the kidneys, lower limbs and orbits by means of dopplervelocimetry in SCA patients, and its relationship with hemolysis biomarkers. Two groups were examined in this cross-sectional study. One group consisted of 71 outpatients with SCA; the other group was a control group, consisting of 32 age- and sex-matched, apparently healthy subjects. All participants were assessed by means of Doppler ultrasound and laboratory tests. All biomarkers were abnormal in the SCA patients compared with the control subjects (p < 0.0001). Doppler sonography evaluation revealed altered velocities and elevated resistance indices RI (resistive index) and PI (pulsatility index) in SCA group compared to control group (p < 0.0001). The relationship analysis between hemolysis biomarkers and vascular resistance indices showed significant association. In the kidneys, strong inverse correlation was observed between hemoglobin level and RI and PI in all arteries; moderate direct correlation was detected between lactate dehydrogenase and the resistance indices in segmental arteries. In the lower limbs, moderate direct correlation was observed between reticulocyte count and peak systolic velocity (PSV) in the anterior tibial and posterior tibial arteries; strong inverse correlation was detected between hemoglobin and PSV in all arteries. In orbits, moderate direct correlation was found between reticulocyte count and resistance indices in ophthalmic artery; and strong inverse correlation was observed between hemoglobin and RI and PI in the central retinal artery. This research demonstrated that arterial vascular resistance in the kidneys, lower limbs and orbits, assessed by means of Doppler ultrasound, is elevated in SCA patients, and shows moderate to strong correlation with hemolysis biomarkers.