Incompatible Minor Crossmatch due to T-transformed red cells a case report

The exposure of cryptantigens on the Red Blood Cell (RBC) membrane is one of the known causes for incompatible minor cross match. It causes agglutination of altered red blood cells by a large proportion of ABO compatible adult human sera - the phenomenon is called polyagglutination. Historically Polyagglutination was first descri bed as an in vitro phenomenon caused by bacterial contamination of RBC suspension. Case Report A 27 year old male patient with the history of chronic renal disease with hemoglobin of 6gmdl required two units of blood for transfusion. ABO and Rh typing was done and his blood group was O ve. Three units of group matched donor blood samples were cross matched and found to be compatible with major cross match and incompatible with minor cross match. These donor samples were screened for unexpected antibodies and found negative. DAT and IAT was negative for both donor and patients and auto control was negative. There was positive reaction with adult sera and no agglutination with Cord Sera. Screening for polyagglutination was done by Lectins. Patient sample was agglutinated with Dolichos biflorus and not by Arachis hypogea.TN polyagglutination was confirmed by specific lectin Salvia sclarea Conclusion This study suggests, if the presence of other antibodies in donor serum are ruled out, in the event of incompatible minor crossmatch, always the possibility of the exposure of hidden antigens on RBCs either in vivo or vitro has to be considered and the same may be confirmed with the help of specific lectins.