Optical laser trapping for studying the deformability of sickle red blood cells in response to hydroxyurea

Abstract

Background: Sickle cell disease (SCD) is prevalent in Basrah city and affects the red blood cell (RBC) deformability and thereby causes disease symptoms. Hydroxyurea (HU) is effective in reducing morbidity and mortality in SCD patients by different mechanisms. Objectives: The aim of the study was to investigate the effect of HU on RBC deformability among SCD patients by direct laser optical trapping (OT) technique. Materials and Methods: Blood samples from SCD patients and control groups were prepared in the medical laboratory of Basrah Center for Hereditary Blood Diseases and transferred into physics laboratory wherein the laser system was presented and built-in. RBCs from each sample were exposed to three different powers of laser 5, 15, and 20 mW for 15 s and then were released and followed for 2 min. The images for each trapped RBC were obtained and at relaxation sequential times. The percentage changes in the diameters of trapped RBCs were measured for control and patient groups. Results: SCD patients were divided into two groups depending on whether they were receiving HU (39 patients) or not (43 patients). They were matched with 50 healthy individuals (control) regarding age and gender. We found that all the trapped RBCs were affected during the trapping time and then returned toward near normal with some differences between the groups and according to the power used. The deformability of HU group was better and closure to the control. Conclusion: The presented laser system and OT technique with optimal power are effective to study the RBC characteristics and deformability. HU is effective in improving RBC deformability among SCD patients.