The present invention relates to methods for determining the risk of severe complications in hemolytic diseases. The present invention relates to a method for determining whether a patient suffering from sickle 
cell disease is at risk for a vaso-occlusive crisis comprising the steps consisting of i) determining the level of 
cell microparticles in a blood sample obtained from said patient and ii) determining the level of 
heme and / or 
hemoglobin contained in said 
cell microparticles. The present invention also relates to a method for a method the 
severe complication in hemolytic diseases comprising the steps consisting of i) determining the level of cell microparticles in a blood sample obtained from said patient and ii) determining the level of 
heme and / or 
hemoglobin contained in said cell microparticles. The present invention also relates to a method for preventing a vaso-occlusive crisis in a patient afflicted with by sickle cell 
disease comprising depleting the blood-borne microparticles laden in 
heme and 
hemoglobin from the blood of said patient.