Expression Pattern of CD55 and CD59 on Red Blood Cells in Sickle Cell Disease

Background: Altered expression of glycosylphosphatidylinositol (GPI)-anchored proteins, might result in increased susceptibility of red blood cells (RBCs) to complement-mediated lysis. Limited information is available on the pattern of CD55 and CD59 expression on RBCs of sickle cell disease (SCD) patients.

Methods: Flow cytometric analysis was performed on RBCs from 71 adult SCD patients and 53 healthy controls, using the commercial REDQUANT kit.

Results: CD59 deficiency was significantly higher among SCD patients than among healthy controls. The proportions of CD55-deficient and CD59-deficient RBCs from SCD patients were significantly higher when compared with those from healthy controls (0.17 vs. 0.09 and 2.1 vs. 1.2, respectively). The MFI of CD55 and CD59 expression on RBCs in SCD was significantly reduced when compared to the expression healthy controls (5.2 vs. 6.4 and 19.4 vs 20.3, respectively). The pattern of CD55 and CD59 expression was not correlated with anemia, biomarkers of hemolysis, erythropoietin level or other pro-inflammatory markers.

Conclusions: There is an altered pattern of CD55 and CD59 expression on RBCs of SCD Patients; however, it does not seem to play a causal role in the pathophysiology of anemia, and is unlikely to be influenced by the level of erythropoietin or other inflammatory mediators.