Inherited paternal antigens induce pregnancy thrombocytopenia

Objective of this study was to investigate the correlation of body-carried inherited paternal antigens (IPA) in one mother after delivery with pregnancy thrombocytopenia. The changes of platelet (Plt) count in the mother who delivered 2 years ago and her child who is now one year's old were detected, routine tests included Helicobacter pylori, CMV, EBV, parvovirus and other herpes virus's infection were carried out. Eight insertion or deletion sites (InDel) SNP with strong polymorphisms in Chinese population was selected to detect IPA from a genomic library, then primers were designed, the nested PCR and real-time quantitative PCR were used to detect 54 healthy mother-child pairs, the obtained average value was taken as the control, finally two InDel polymorphism sites between mother and child were used to identify the mother/child microchimerism. The IPA of the mother were examined at 4 time points. The results showed that the Plt level of the mother who had suffered thrombocytopenia since 20 weeks after pregnancy reduced to 10 × 10(9)/L. After using gamma globulin, the Plt count increased gradually, but the Plt count decreased rapidly when withdrawal. This patient did not have the infections of virus and Helicobacter pylori. IPA average value of 54 cases were from 10(-5) to 10(-4). At 67 d after delivery, the Plt count of the mother was 14 × 10(9)/L, IPA was 3.45 × 10(-3), which was 30 times higher than the normal. In one month after treatment the IPA was 1.3 × 10(-4) (Plt 256 × 10(9)/L), 5 months later it was 1.2 × 10(-4) (Plt 158 × 10(9)/L), and 6 months later it was 1.5 × 10(-4) (Plt 325 × 10(9)/L). When IPA reached the normal level, the Plt count returned to normal. Her child suffered thrombocytopenia (4 × 10(9)/L) one month after he was born, then recovered after high-dose gamma globulin therapy. It is concluded that abnormal high level IPA may lead to pregnancy thrombocytopenia.