Identification of anti-Jra antibodies by serology and mass spectrometry
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 anti-gens 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-Jraantibody.JR blood type genotyping was per-formed 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 Jraantigen was negative in sero-logical tests and mass spectrometry blood type genotyping.Mass spectrometry revealed a homozygous nonsense mutation(c.376C>T)in exon4.The anti-Jra antibody titer was1∶2.Conclusion The patient developed high-frequency anti-Jraantibod-ies during pregnancy.