Erythropoietin (EPO) Plasma Levels Reflect the Course of Clinical Vaso-Occlusive Complications in Sickle Cell Disease.

Erythropoietin (EPO) has an important role in both erythropoieses and angiogenesis. EPO levels are elevated in sickle cell patients due to severe anemia, but tissue hypoxia, due to for example vaso-occlusion, may also contribute to EPO elevation. In this study we sequentially determined EPO plasma levels in HbSS sickle cell patients (n=14, 39 samples) presenting with vaso-occlusive complications at our emergency ward and the period thereafter. Patients were also requested to fill out a pain-intensity score during these events. Our results show a striking correlation between the course of vaso-occlusive events and plasma EPO levels. Vaso-occlusive crises were accompanied by impressive increments of plasma EPO levels with quick reduction of plasma EPO levels upon crisis amelioration. Changes in plasma EPO levels also closely reflected changes in pain intensity. The results of this study warrant further analysis of the potential role of EPO in the pathophysiology of sickle cell disease related complications, as well as the applicability of employing EPO levels as a marker of vaso-occlusive disease activity.