Copy number variations ofPlasmodium vivax DBP1,EBP/DBP2, andRBP2bin Duffy-positive and Duffy-negative Ethiopians

Abstract

AbstractRecent evidence challenges the belief that Duffy-negative individuals are resistant toPlasmodium vivaxdue to lacking Duffy Antigen Receptor for Chemokines (DARC). Erythrocyte Binding Protein (EBP/DBP2) has shown moderate binding to Duffy-negative erythrocytesin vitro. Reticulocyte Binding Protein 2b (RBP2b) interactions with Transferrin Receptor 1 (TfR1) suggest involvement in Duffy-negative infections. Gene copy number variations inPvDBP1,PvEBP/DBP2, andPvRBP2bwere investigated in Duffy-positive and Duffy-negativeP. vivax-infected individuals from Ethiopia. Among Duffy-positive samples, 34% displayedPvDBP1duplications (Cambodian-type). In Duffy-negative infections, 30% showed duplications, mostly Cambodian-type. ForPvEBP/DBP2andPvRBP2b, Duffy-positive samples exhibited higher duplication rates (1-8 copies forPvEBP/DBP2, 1-5 copies forPvRBP2b46% and 43% respectively) compared to Duffy-negatives (20.8% and 26% respectively). The range of copy number variations was lower in Duffy-negative infections. Demographic and clinical factors associated with gene multiplications in both Duffy types were explored, enhancing understanding ofP. vivaxevolution in Duffy-negative Africans.