Identification of anti-Jra antibodies by serology and mass spectrometry

Abstract

Objective To report the antibody specific identification process of a pregnant woman who had no history of blood transfusion but presented high-frequency anti-Jra antibodies. Methods Antibody screening and identification were performed by saline and indirect Coomb’s technique (microcolumn gel card, PEG). ABO, Rh and other blood group antigens were identified by saline. Further antibody identification tests were performed by the reaction between cells treated with various enzymes and patient plasma. Jra antigen was identified by human anti-Jra antibody. JR blood type genotyping was performed by MALDI-TOF mass spectrometry detection system. Antibody titer in serum was tested. Results The patient′s blood type was O with RhD(+ ) and CcDEe. The plasma reacted negatively with antibody screening and identification cells by saline, but positively by indirect globulin test. The self-control was negative. The patient′s Jra antigen was negative in serological tests and mass spectrometry blood type genotyping. Mass spectrometry revealed a homozygous nonsense mutation (c.376C>T) in exon 4. The anti-Jra antibody titer was 1∶2. Conclusion The patient developed high-frequency anti-Jra antibodies during pregnancy.

Keywords

• plasma
• jra antigen
• anti-jra antibody