Association between Duffy antigen receptor expression and disease severity in sickle cell disease patients

Sickle cell disease (SCD) is associated with a pro-inflammatory state, characterized by an elevated baseline leukocyte count and inflammatory cytokines. Inflammation, white blood cell (WBC) adhesion to vascular endothelium with subsequent endothelial injury, and repeated ischemia-reperfusion injury contribute to disease pathogenesis. Identification of genetic polymorphisms that may modulate disease severity in SCD is becoming a field of interest. The Duffy blood group antigen has been identified as a receptor for various chemokines involved in neutrophil activation and trafficking. This study aimed at investigating the effect of RBCs' Duffy antigen expression and its genetic polymorphisms on modulating disease severity and its complications among Egyptian sickle cell patients. Methods We analyzed the association of Duffy genotypes and phenotypes with clinical expression of SCD in 100 Egyptian patients. The Duffy phenotype expression was detected by indirect anti-globulin test while Duffy genotyping was conducted with polymerase chain reaction-restriction fragment length polymorphism-based assay. Results Total WBC count was strongly associated with Duffy genotype. WBCs were significantly higher in Duffy-positive patients (P = 0.002). No statistical significance was evident between individual measures of disease severity (pulmonary dysfunction, avascular necrosis, central nervous system dysfunction, kidney dysfunction, and leg ulcers) and Duffy genotype. Conclusion Our study suggests that RBC Duffy expression increases levels of WBCs in SCD patients and that Duffy genotype may not be a potential biomarker for end-organ damage in SCD.