Coronavirus disease-2019 (COVID-19) has infected millions of people with high lethality in the world, but little is known whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has impacts on triggering pediatric acute lymphoblastic leukemia (ALL). We present a case of a child with atypical clinical manifestation who developed B-cell acute lymphoblastic leukemia following a mild symptomatic COVID-19 infection. This case underlines the risks of potential oncogenic effects with the history of this viral infection and a state of immunosuppression.

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 and objective: Immune thrombocytopenia (ITP) is an autoimmune-mediated hemorrhagic disease, which is characterized by thrombocytopenia and bleeding manifestation. The treatment options of ITP in children are selected based on bleeding severities and the treatment selection is critical in children with a serious decline in platelet count (platelet count of <10×10 9/L). Although it is well known that platelet-specific antibodies play a key role in ITP, the relationship between different platelet-specific antibodies and bleeding severities is unclear. This study aimed to analyze the relationship between platelet-specific antibodies (anti-GPIIb/IIIa and anti-GPIb/IX antibodies) and bleeding severities in children with newly diagnosed ITP and a serious decline in platelet count. Method: This study was a single-center prospective observational study that analyzed children with newly diagnosed ITP and platelet count of less than 10×10 9/L from June 2018 to September 2021 in our Hospital. They were classified into mild-moderate and severe groups based on the treatments. Platelet-specific antibodies and titers were detected using a kit, PAKAUTO. We analyzed the relationship of bleeding severities with platelet-specific antibodies/titers . Results: A total of 86 cases were enrolled including 57 males and 29 females with a median age of 35 months (range 1 month to 198 months). And 11 cases were categorized as the mild-moderate group and 75 cases were categorized as the severe group based on bleeding severity score. The positive rates were 68.6% for anti-GPIIb/IIIa and 65.1% for anti-GPIb/IX. There was no significant difference in anti-GPIIb/IIIa and anti-GPIb/IX antibodies between the two bleeding severity groups ( χ2=0.530, P=0.467; χ2<0.001, P=1.000), and also no difference was found between the two groups when two antibodies were analyzed together ( χ2=2.071, P=0.558). The antibody titers in plasma and eluent were also detected, but no significant difference was found in the antibody titer ratios between the two bleeding severity groups ( P<0.05 in four plasma and eluent groups). Conclusion: Platelet-specific antibodies (anti-GPIIb/IIIa and anti-GPIb/IX antibodies) were not related to the bleeding severities in children with newly diagnosed ITP and serious decline of platelet count.

Objective: To analyze the effect of a novel second-line escalating treatment strategy (high-dose dexamethasone (HDD), low-dose rituximab to eltrombopag) for children with severe chronic immune thrombocytopenia (SCITP). Materials and Methods: This study was a single-center, retrospective cohort study. The second-line escalating strategy included 3 steps: Step I (6 courses high-dose dexamethasone: HDD), Step II (HDD combined with low-dose rituximab), and Step III (eltrombopag). Results: A total of 30 cases (18 males and 12 females) were included; the median age was 8.83 (1.42-13.9) year-old, the duration time of ITP was 20.5 (12.0-96.0) months, and the platelet counts were 15 (3-29) ×109/L. After the median 14 (12-37) months’ treatment, the remission rate was 36.7% (11/30), and the sustained response (SR) rate was 68.2% (15/22). In eltrombopag (step III) cases, 47.5% (8/17) maintained platelet ≥50×109/L, 37.5% (3/8) dose tapering, and 25% (2/8) were successfully discontinued from medication. The number of patients at 12th, 24th, and 36th months was 30, 7, and 2, with the total response (TR) and remission rates of 80% (36.7%), 57.1% (28.6%), and 50% (50%), respectively. The total relapse rate was 26.7% (8/30)，three cases(75%, 3/4)from Step II and 5 cases (41.7% ,5/12)from Step III, none in Step I. Conclusion: The new second-line escalating strategy for children SCITP has an effective improving rate with 36.7% remission and 68.2% SR; 30% could benefit and retain stable response from HDD treatment. Combined treatment with eltrombopag can reduce the relapse rate of low-dose rituximab.

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.