Background:The thrombopoietin receptor agonists (TRAs) were recommended for primary immune thrombocytopenia (ITP) during the pandemic of COVID-19. However, the incidence of thrombocytosis and thrombosis was sporadically reported in the chronic immune thrombocytopenia (CITP) patients receiving TRAs during the COVID-19 infection. Objective: With the local prevalence of COVID-19 in Dec 2022 in the Beijing area, we got more powerful evidence about the change in platelet (Plt) counts associated with COVID-19 infection. Methods: A signal center observational cohort study was performed from the beginning of Dec. 2022 to the end of Feb. 2023 to enroll CITP children treated with TRAs alone as the second-line treatment and suffering from the COVID-19 infection in Dec. 2022. The Plt counts before, during, and after COVID-19 infection were collected. Results: In total, 67 (34 males and 33 females) patients with 8.10 (2.15, 15.70) years of age were enrolled. Sixty-three patients who had responded to the TRAs showed a transient increase in Plt counts after the infection of COVID-19. The time of starting to increase was on Day 3(2,7), and to the peak level on Day 14(7,19) of infection with the peak Plt count was 289 (88, 1974)×10 9/L. With at least two months observation period from COVID-19 infection, the Plt counts of 100% (63/63) patients declined to the baseline on Day 25(14, 41). Conclusion: The phenomenon of transient increasing of Plt counts has been shown in the CITP children who have treatment responses to TRAs when suffering from COVID-19 infection.

Background: Eltrombopag (E-PAG) is being investigated for the treatment of aplastic anemia (AA) by stimulating hematopoietic stem cell (HSC) proliferation. Objective: To evaluate the effectiveness and safety of E-PAG in first-line therapy for pediatric AA. Methods: The present retrospective study reviewed the pediatric patients with newly diagnosed AA in immunosuppressive therapy (IST) therapy with E-PAG at the single center from March to September in 2017. All patients were followed up for >2 years. Results: A total of 14 patients (8 males), aged 86 months, were enrolled in this study. E-PAG was administered with a median time to initiation of 19.5 days after IST, and the median course of treatment was 253 days. The rate of complete response and overall response at 6 months were 64.3% (9/14 case) and 78.6% (11/14 cases) respectively. The survival rate was 100%, and no relapses occurred in responders. E-PAG was well-tolerated; however, the most common adverse events included indirect bilirubin elevation, jaundice, and transient liver-enzyme elevation. By the end of follow-up, bone marrow chromosomes were normal, and no abnormal myelodysplastic syndromes (MDS) -related clones appeared. Conclusions: The addition of E-PAG to IST was associated with the markedly increased complete response with respect to hematology in pediatric patients with SAA than in a historical cohort without the unacceptable side effects.