The Establishment of a Novel Murine Model of Immune Thrombocytopenia in Pregnancy and the Impacts of Thrombopoietin Receptor Agonist on Platelet Production.

Objective Immune thrombocytopenia (ITP) is frequently associated with pregnancy. However, treatment options for ITP in pregnancy are limited, and there are few animal models available for the establishment of treatments. Here, we aimed to establish a novel murine pregnant model of ITP and to investigate the impacts of thrombopoietin receptor agonist (TPO-RA) on platelet production and reproductive outcomes. Methods Anti-glycoprotein Ib-alpha (GPIbα) antibody, which binds to megakaryocytes and platelets, was subcutaneously administered to pregnant mice in order to develop an ITP model (ITP group). TPO-RA was given in doses of 1 µg/kg, 10 µg/kg, and 100 µg/kg (low-dose group, mid-dose group, and high-dose group, respectively) for the treatment of ITP in pregnancy. Results The ITP group showed a significant reduction of platelet counts of less than 15% of healthy pregnant mice (control group) and also showed a significant increase in miscarriage rate (control group, 3.8%; ITP group, 44.4%; p < 0.05). Striking increases in platelet counts were observed in every TPO-RA group without any negative effects on fetal growth and placental pathology. No abnormality was noted in the external examination of fetal mice. Interestingly, a significant recovery of miscarriage rate was observed in the mid-dose group (23.5%) compared with the ITP group (p < 0.05). Conclusion A novel ITP model in pregnant mice was induced by injection of an anti-GPIbα antibody, and sufficient effects of TPO-RA on platelet production were observed in the present study. Furthermore, the positive impacts of TPO-RA on reproductive outcomes were revealed in the ITP model.