A 52 years old woman with ruptured esophageal varix, who had hemolytic transfusion reaction without any detectable irregular antibodies in her serum, was reported. She had history of twice blood transfusions on each caesarean operation in 1979 and 1980.
She has received 10 units of fresh whole blood from 16 to 18 May in 1988. Ten days after blood transfusions, she noticed hemoglobinuria. Laboratory tests showed increase in LDH and indirect bilirubin levels with decreased haptoglobin level.
The irregular antibodies were weakly detected in her serum by low ionic strength polybren method on the Autoanalyzer, but not by saline, albumin, bromelin and indirect antiglobulin method. Specificity of the antibodies were anable to be identified, and direct antiglobulin test wa negative. The blood groups of the patient were A1, ccDee. She received blood with Rh phenotype of ccdee. Ever since, she has been saved from occurrences of any hemolytic reactions. Thus delayed hemolytic transfusion reaction by anti-E+C was mostly suspected, though irregular antibodies could not be detected in her serum in March, 1989.