This is from the Winrho package insert: "After administration of WinRho® SDF, a transitory increase of various passively transferred antibodies in the patient’s blood may yield positive serological testing results, with the potential for misleading interpretation. Passive transmission of antibodies to erythrocyte antigens (e.g., A, B, C and E) and other blood group antibodies [for example, anti Duffy, anti Kidd (anti JKa) antibodies]5 may cause a positive direct or indirect (Coombs’) test."