Eleven Years' Experience with Unexpected Antibody Screening Tests Including a Di(a) Cell in Transfusion Candidates / 대한수혈학회지

BACKGROUND: The Di(a) antigen has been detected with a relatively higher incidence among the Korean and Southeast Asian population. A 'Type and Screen' procedure is recommended for efficient transfusion, therefore, we perform antibody screening tests using antibody screening panels containing a Di(a) cell. The purpose of this study was to report on the experience of unexpected antibody screening test including a Di(a) cell in the Korean population. METHODS: We analyzed the results of antibody screening testing and identification performed during the recent 11-year period from January 2002 to December 2012. A commercially available three-cell antigen panel (Diacell I, II, Di(a); DiaMed, Murten, Switzerland) was used for antibody screening. Antibodies were identified using a LISS/Coombs gel card and NaCl/Enzyme card, using the DiaMed-ID system (DiaMed, Murten, Switzerland). RESULTS: The frequency of unexpected antibodies was 1.23% (1,918/156,161); the most frequently detected antibodies were anti-E (292 samples), followed by anti-E,c (127 samples), anti-Le(a) (103 samples), and anti-Di(a) (91 samples). CONCLUSION: Results of this study showed that the most identified unexpected antibodies were clinically significant, and, in particular, anti-Di(a) antibodies are detected frequently in the Korean population. Thus, unexpected antibody screening test including a Di(a) cell is thought to be helpful in Korea for safe transfusion.

A Case of Hemolytic Disease of a Newborn by an Anti-Di(a) Antibody Treated with Intravenous Immunoglobulin / 영남의대학술지

Hemolytic disease in a newborn that causes early jaundice is common. It is often due to the Rh (D) and ABO incompatibility, but rarely due to unexpected antibodies. Among these unexpected antibodies, the anti-Di(a) antibody rarely occurs. The anti-Di(a) antibody was observed in the serum and red-cell eluate of an infant, and in the serum of his mother. The frequency of the appearance of the Di(a) antigen in the Korean population is estimated to be 6.4-14.5%. This paper reports a case of hemolytic disease in a newborn associated with the anti-Di(a) antibody. A full-term male infant was transferred to the authors' hospital due to hyperbilirubinemia the day after his birth. The laboratory data indicated a hemoglobin value of 11.6 g/dL, a reticulocyte count of 10.6%, a total bilirubin count of 14.4 mg/dL, a direct bilirubin count of 0.6 mg/dL, and a positive result in the direct Coombs' test. Due to the identification of an irregular antibody from the maternal serum, an anti-Di(a) antibody was detected, which was also found in the eluate made from the infant's blood. The infant had been treated with phototherapy and intravenous immunoglobulin since the second day after his birth and was discharged due to an improved condition without exchange transfusion. Therefore, in cases of iso-immune hemolytic disease in a newborn within 24 hours from birth who had a negative result in an antibody screening test, the conduct of an anti-Di(a) antibody identification test is recommended due to the suspicion of an anti-Di(a) antigen, followed by early administration of intravenous immunoglobulin.