RESUMO
BACKGROUND: The Yt system consists of five antigens: antithetical Yta /Ytb and the high-prevalence antigens YTEG, YTLI, and YTOT. We investigated a sample from a Native American (NA) female with post-operative anemia and an unidentified antibody who developed rigors, tachycardia, and hypotension on transfusion of incompatible RBCs. METHODS AND MATERIALS: Serologic testing methods included LISS, PEG, and IgG gel. Test RBCs were treated with papain, trypsin, alpha-chymotrypsin, 2-amino-ethylisothiouronium, and dithiothreitol. Rare RBCs were tested, and inhibition studies were performed. DNA extracted from WBCs was used for Sanger sequencing. RESULTS: Initial testing showed strong 3-4+ plasma reactivity with all panel cells at LISS IAT; auto control was negative. Positive reactions were observed with numerous rare RBCs except for PNH-III, which lack GPI-linked DO, Yt, CROM, JMH, and Emm. Enzyme sensitivity patterns suggest Yt specificity, and soluble recombinant srYt neutralized reactivity. ACHE sequencing revealed YT*A/A genotype but with a homozygous change in exon 2, c.290A>G (p.Gln97Arg). Antibody reactivity was reminiscent of that seen in an unrelated NA male investigated previously. His RBCs were nonreactive with her plasma. ACHE carried the same c.290G/G change. CONCLUSION: Two unrelated NA patients were found to have an antibody to a new high-prevalence Yt antigen, designated YTGT (YT6), associated with a clinically significant transfusion reaction. Identification of the specificity relied on enzyme sensitivity, use of PNH-III RBCs, neutralization using soluble recombinant Yt, and the finding of a novel change in ACHE, c.290A>G (p.Gln97Arg), designated YT*01.-06. IVIG and steroids were used to mitigate further reactions to transfusion.
Assuntos
Antígenos de Grupos Sanguíneos , Isoanticorpos , Antígenos de Grupos Sanguíneos/genética , Transfusão de Sangue , Feminino , Humanos , Masculino , Prevalência , Indígena Americano ou Nativo do AlascaRESUMO
Sedimentation of Apheresis Granulocyte components removes red blood cells. It is used to increase the blood donor pool when blood group-compatible donors cannot be recruited for a patient because of a major ABO incompatibility or incompatible red blood cell antibodies in the recipient. Because granulocytes have little ABO and few other red blood cell antigens on their membrane, such incompatibility lies mostly with the contaminating red blood cells. Video Clip S1 shows the process of red blood cell sedimentation of an Apheresis Granulocyte component. This video was filmed with a single smart phone attached to a commercial tripod and was edited on a tablet computer with free software by an amateur videographer without prior video experience.
