Avaliação dos níveis de VCAM-1 e sua correlação com os biomarcadores de hemólise em pacientes com anemia falsiforme

Abstract

Patients with sickle cell anemia (SCA) present vaso-occlusion as their main clinical manifestation, which occurs through adhesion of red blood cells with hemoglobin S (HbS) in a polymerized state and cells of the immune system to the vascular wall. These erythrocytes act as a promoter or initiator component of this phenomenon, binding to vascular endothelial cells via integrin complexes (VLA-4). In addition, these erythrocytes and vaso-occlusion consequently induce a significant increase in the expression of the gene encoding VCAM-1 (vascular cell adhesion molecule-1), which binds to VLA-4 and induces attachment to the endothelium with consequent vascular occlusion, and this manifestation is fed back by the elevation of the levels of pro-inflammatory cytokines at the vascular level and the reduction of the concentration of nitric oxide (NO). patients with SCA over 18 years of age (mean age 34.98 years ± 10.27) of both genders and their correlation with HbF levels, hydroxyurea (HU) use and hemolysis markers (degree of anemia, LDH , bilirubin and reticulocyte count). The participating patients had a confirmed diagnosis of AF by Hb electrophoresis and/or high performance liquid chromatography (HPLC), of which 50 used HU. The control group consisted of 34 individuals of both sexes over 18 years of age who were blood donors with the HbAA genotype. Socio-epidemiological and laboratory data were obtained from medical records. VCAM-1 serum levels were measured using a peripheral blood sample collected in a separator gel tube, and quantification was performed using the ELISA technique. Statistical analysis was performed using IBM SPSS version 23 and GraphpadPrism version 6.0 programs. The statistical tests used were: unpaired t test, Pearson's correlation, ROC curve and chi-square test. The p cut-off value for rejecting the null hypothesis was 0.05 (5%). It was established, after comparison, that serum levels of VCAM-1 were significantly higher in patients with SCA than in subjects in the control group. In the correlation analysis between VCAM-1 serum levels and hemolysis parameters in patients with SCA, all hemolysis biomarkers, with the exception of reticulocyte count, showed a statistically significant correlation. In the analysis of correlation between VCAM-1 serum levels and fetal hemoglobin (HbF) values in patients with SCA, no statistically significant correlation was observed. In the analysis carried out to compare the serum levels of the molecule with the presence or absence of severe anemia, it was found that patients with SCA in a state of severe anemia had higher serum levels of VCAM-1. When comparing VCAM-1 serum levels between patients who used and those who did not use hydroxyurea (HU), there was no statistically significant difference. It was concluded that the data demonstrate that VCAM-1 is promising as a predictive biomarker for the degree of anemia and hemolysis.