Elevated endothelial progenitor cells during painful sickle cell crisis
Rachel T van Beem1, Erfan Nur, Jaap Jan Zwaginga
1Department of Experimental Immunohematology, Sanquin Research and Landsteiner Laboratory, Amsterdam, The Netherlands.
Experimental Hematology
|June 23, 2009
Summary
Endothelial progenitor cell (EPC) counts are low in sickle cell disease (SCD) patients when asymptomatic but significantly increase during painful crises, suggesting a role in healing. The mechanism for this EPC increase in SCD remains unclear.
Area of Science:
- Hematology
- Vascular Biology
- Regenerative Medicine
Background:
- Sickle cell disease (SCD) is characterized by vaso-occlusion and chronic organ damage.
- Endothelial progenitor cells (EPCs) play a crucial role in vascular repair and angiogenesis.
- Understanding EPC behavior in SCD is vital for developing therapeutic strategies.
Purpose of the Study:
- To quantify circulating EPCs in SCD patients.
- To investigate the relationship between EPCs and SCD-related ischemia.
- To explore the role of EPCs in angiogenesis and reendothelialization in SCD.
Main Methods:
- Circulating EPC counts (KDR(+)/CD34(+)/Cd45(dim) cells) were measured.
- EPC levels were assessed in SCD patients during asymptomatic periods and painful crises.
- Comparisons were made with healthy controls.
- Serum levels of EPC-mobilizing growth factors were analyzed.
Main Results:
- EPC counts were negligible in asymptomatic SCD patients and controls.
- EPC counts significantly increased during painful crises in SCD patients.
- A paired analysis confirmed a significant rise in EPCs during painful crises.
- No correlation was found between EPC counts and measured growth factors (erythropoietin, VEGF, IL-8).
Conclusions:
- Elevated EPC counts during painful crises suggest a potential role in reendothelialization processes.
- The mechanism driving EPC mobilization in SCD is not explained by the studied growth factors.
- Further research is needed to elucidate the exact mechanism of EPC mobilization in SCD.
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