Adhesion Molecules Interaction with Markers of Lipid Metabolism, Hemolysis, Endothelial Dysfunction and Medical Histories Among Steady-State Sickle Cell Anemia Patients.

Sickle cell anemia (SCA) results from the homozygous form of hemoglobin S (Hb S). Vaso-occlusive pain episodes underlie most of the acute and chronic clinical complications of disease and it is correlated with activation of red blood cells, leukocytes, platelets and endothelial cells that express several adhesion molecules and ligand. The aim of the present study was investigates the levels of soluble ICAM-1 and VCAM-1 adhesion molecules associating with biochemical markers, expression of neutrophils adhesion molecule and medical history of sickle cell anemia patients. Patients and Methods. We studied 53 SCA patients in steady-state (25 men, 28 women, mean age: 21.17 ± 14.12 years) from northeast Brazil diagnosed with SCA in attendance of the outpatients clinic of the Foundation of Hematology and Hemotherapy of Bahia (HEMOBA). The control group was compound by 22 healthy Brazilian, with AA hemoglobin pattern matched by age, years and ethnic origin. Biochemical analyses were measured by colorimetric methods, surface adhesion molecules expressions by flow cytometry, soluble adhesion molecules by ELISA and the complete medical history was obtained by patients' record.

Our results show a higher serum levels of VCAM-1(s) in patients than control group (p=0.006). Moreover, in this study we found low expression of neutrophils CD18 in patients with high levels of VCAM-1(s). Total cholesterol and low density lipoprotein (LDL-C) were significantly negative associated with VCAM-1(s) (r=−0.312, p=0.023; r=−0.282, p=0.041 respectively) and the high density lipoprotein (HDL-C) was significantly negative associated with ICAM-1(s) (r=−0.348; p=0.011). Intravascular hemolysis markers such as aspartate transferase (AST) and lactate dehydrogenase (LDH) were significantly positive associated with VCAM-1(s) (r=0.459, p=0.001 and r=0.281, p=0.041, respectively). Sickle cell anemia individuals that developed necrosis and leg ulcers exhibited high serum level of VCAM-1(s) (p=0.017 and p=0.021 respectively) and patients that presented priapism had low levels of ICAM-1(s) (p=0.046).

The presence of high levels of ICAM-1(s) and VCAM-1(s) adhesion molecules and its association with markers of intravascular hemolysis, endothelial dysfunction and lipid metabolism may indicate a differentiated mechanism of these molecules in sickle cell anemia pathogenesis, with a complex involvement of cellular, endothelial and proinflammatory interactions. The measurement of soluble adhesion molecules is of easy determination and may be an important biomarker of prognosis among sickle cell anemia patients. Additional studies should be carried out in order to explore the contribution of ICAM-1 (s) and VCAM-1 (s) in other signal pathways.

No relevant conflicts of interest to declare.