Abstract

 Background and Objectives

 The unexpected alloantibodies are usually found in the sera of those patients who have a history of blood transfusion and pregnancy. These alloantibodies cause many complications in patients with post-transfusion delayed hemolytic transfusion reactions.

 Case

 A 24-year-old man with melana, blood vomiting, and the history of discopathy and consumption of moleksicam was observed . In laboratory tests, incompatibility of the cross-match test and discrepancy of blood grouping were observed. In the analysis of the antibody screening, positive reactions were observed with all of the cells in different phases of panels 3 and 11. On the next visit, similar results were obtained after 6 months.

 Conclusions

 If indicated for blood transfusion, only autologous blood is recommended to be administered to prevent hemolytic transfusion reactions.