Jae Won Yoo

Background: Real-world data (RWD)–based pediatric acute lymphoblastic leukemia (ALL) registries often face scalability and reliability limits owing to manual data entry and inter-institutional heterogeneity. We evaluated the feasibility of building an automated, high-quality registry using electronic medical records (EMR) and clinical data warehouses (CDWs) to quantitatively assess the Pediatric ALL Automated Registry (PeARL) for (1) automatic extractability (ADE) (2), data quality, and (3) multicenter applicability. Methods: In this study, we used CDWs to identify patients aged < 18 years with ALL (ICD-10 C91.0) who visited Seoul National University Hospital (SNUH) and the Catholic Medical Center (CMC). between 1990 and 2023. An automated extraction pipeline applied standard mapping, multivariate transformations, and rule-based natural language processing (NLP). Key variables were selected using the Medical Information Standards for Hematologic Cancer. Data quality was evaluated based on 228 rules across five dimensions (completeness, validity, accuracy, uniqueness, and consistency) based on DQ4HEALTH; error rates, defined as the proportion of data elements violating these rules, were calculated before and after quality management. Results: Overall, 1,609 patients were included (CMC 946; SNUH 663). ADE for key variables was 89.7% at SNUH and 75.0% at CMC; most automations were single-field transformations (SNUH 61.8%; CMC 84.7%), with multivariate transformations and rule-based NLP addressing complex elements. Initial overall error rates were 1.858% (SNUH) and 0.129% (CMC), decreasing to 0.001% at both institutions after quality processes. Differences in CDW structure required additional preprocessing for laboratory and transplant variables, but harmonization was achieved via standardized table specifications and cross-site review. Conclusions: PeARL integrated standardized mapping, multivariate transformations, and rule-based NLP to enable large-scale automation of a pediatric ALL registry, achieving a 0.001% overall error rate under DQ4HEALTH-based quality management. This clinically guided, standardized framework enables reproducible implementation and scalable automation of pediatric ALL registry construction, supporting multicenter research and the generation of regulatory-grade real-world evidence. Clinical trial number: Not applicable.

Background: Aplastic anemia (AA) is a rare bone marrow failure syndrome characterized by notably short telomere length, which is associated with treatment responses. In this study, we measured telomere lengths in Korean pediatric AA patients using flow-fluorescence in situ hybridization (Flow-FISH) and explored their shortening in relation to disease characteristics, genetic conditions and patient outcomes. Methods: We analyzed peripheral blood samples from 75 AA patients and 101 healthy controls. Telomere lengths were measured using Flow-FISH, and relative telomere length (RTL) and delta RTL assessments were conducted. Genetic evaluations included karyotyping, chromosome breakage tests and clinical exome sequencing (CES) to identify inherited bone marrow failure syndrome (IBMFS)-associated genetic variants. Results: Telomere lengths in AA patients were significantly lower than those of age-adjusted healthy controls. Patients receiving immunosuppressive therapy tended to have long telomeres, as indicated by high delta RTL values. Patients with genetic abnormalities, including karyotype abnormalities (n = 2) and genetic variants (n = 11) such as carrier genes of IBMFS or variants of unclear significance, showed significantly short telomere lengths. Conclusions: This study reinforces the importance of telomere length as a biomarker in acquired AA. Utilizing Flow-FISH, we were able to accurately measure telomere lengths and establish confidence in this method as an appropriate laboratory test. We found significant reduction in telomere lengths in AA patients, and importantly, longer telomeres were correlated with better outcomes in immunosuppressive therapy. Additionally, our genetic analysis underscored the relevance of variants in IBMFS-associated genes to the pathophysiology of short telomeres.

Background/Objectives: Myeloid neoplasms encompass a diverse group of disorders. In this study, we aimed to analyze the clinical and genomic data of patients with myeloproliferative neoplasm (MPN), myelodysplastic neoplasm (MDS), and their overlapping conditions, such as MDS/MPN and aplastic anemia (AA), to help redefine the disease classification. Methods: Clinico-genomic data of 1585 patients diagnosed with MPN (n = 715), MDS (n = 698), MDS/MPN (n = 78), and AA (n = 94) were collected. Patterns of 53 recurrent genomic abnormalities were compartmentalized into 10 groups using a Dirichlet process (DP). Results: These genomic groups were correlated with specific genomic features, survival outcomes, and disease subtypes. Groups DP1 and DP5, characterized by JAK2 and CALR mutations, respectively, showed very favorable prognoses among the patients with MPN. Groups DP2, DP7, and DP9 demonstrated very adverse prognoses across the disease subtypes. DP2 included patients with MDS harboring TP53 mutations and complex karyotypes; DP9 comprised patients with acute myeloid leukemia-related mutations, including NPM1; and DP7 included patients with SETBP1 mutations. Groups DP10 and DP8, linked to SF3B1 and DDX41 mutations or chromosome 1q derivatives, presented a favorable risk profile. Improved survival was observed with transplantation in groups DP2, DP7, and DP9. Conclusions: These findings highlight the role of genomic classifications in guiding personalized treatment strategies, ultimately enhancing the understanding and management of myeloid neoplasms.

Background: Varicella can lead to severe complications in immunocompromised children, including those undergoing hematopoietic stem cell transplantation (HSCT) or chemotherapy. Preventing primary varicella zoster virus (VZV) infection is crucial in these populations to mitigate morbidity and mortality. This study aimed to evaluate the immunogenicity and safety of the live attenuated MAV/06 varicella vaccine in pediatric patients post-HSCT and post-chemotherapy. Additionally, it sought to compare fluorescent-antibody-to-membrane-antigen (FAMA) and enzyme-linked immunosorbent assay (ELISA) titers to establish effective cut-off levels for protection against varicella. Methods: The FAMA assay was conducted at the Vaccine Bio Research Institute, and a VARICELLA-ZOSTER ELISA (Vircell, Granada, Spain) kit, which relies on lysate from whole cells infected with VZV, was used to determine VZV IgG. A prospective cohort study was conducted with 76 pediatric patients under 18 years old who tested negative for VZV IgG via ELISA. Patients post-HSCT and post-chemotherapy were included. Participants received the MAV/06 varicella vaccine, and serologic responses were evaluated using ELISA and FAMA. Results: The median age of participants was 9.8 years, with acute lymphoid leukemia and acute myeloid leukemia being the most common underlying disease. Post-dose 1, the seropositive rate was 56.1% by ELISA and 97.2% by FAMA. Based on the FAMA seropositive cut-off ≥1:4, post-dose 1 geometric mean titers (GMTs) of seropositive patients in the post-HSCT group were 14.7 (95% CI, 11.3–19.1) versus 20.2 (95% CI, 13.0–31.3) in the post-chemotherapy group (p = 0.690). Based on a FAMA seropositive cut-off ≥1:16, the post-dose 1 GMT of patients considered seropositive in the post-HSCT group was 19.3 (95% CI, 15.6–24.0) versus 34.1 (95% CI, 21.0–55.4) in the post-chemotherapy group (p = 0.116), and post-dose 2 FAMA titers of 76.1 (95% CI, 14.6–398.1) in the post-HSCT group and 64.0 (95% CI, 11.4–358.1) in the post-HSCT group (p = 0.853) were observed. In patients with lower baseline FAMA titers (1:4 to 1:8), 66.7% in the post-HSCT group and 71.5% in the post-chemotherapy group achieved a greater than four-fold increase in FAMA titers post-dose 1, while those with higher baseline titers (≥1:16) did not. There were no serious adverse events or vaccine-related rashes occurring in any of the patients. Conclusion: The MAV/06 varicella vaccine is immunogenic in pediatric patients post-HSCT and post-chemotherapy, particularly when administered in a two-dose schedule using a cut-off FAMA titer of <1:16.

Purpose: Glycated hemoglobin (HbA1c) as a glycemic index may have limited value in pediatric patients with acute leukemia as they often present with anemia and/or pancytopenia. To address this issue, we evaluated the usefulness of glycated albumin (GA) as a glycemic monitoring index in pediatric patients with acute leukemia.Methods: Medical records of 25 patients with type 2 diabetes mellitus (T2DM), 63 patients with acute leukemia, and 115 healthy children from Seoul St. Mary's Hospital, The Catholic University of Korea, were retrospectively investigated for serum GA, HbA1c, and fasting blood glucose (FBG) levels, along with demographic data.Results: GA, HbA1c, and FBG levels did not differ between the control and acute leukemia groups. In the T2DM group, positive correlations were observed among GA, HbA1c, and FBG (P<0.01). Although GA level was not associated with the HbA1c level in the control group, GA and HbA1c levels showed a positive correlation in the acute leukemia group (P=0.045). Regression analysis revealed GA and HbA1c levels to be positively correlated in the acute leukemia and T2DM groups even after adjusting for age, sex, and body mass index z-score (P=0.007, P<0.01).Conclusion: GA may be a useful complementary parameter to HbA1c for glycemic monitoring in pediatric patients with acute leukemia, similar to its use in patients with T2DM.

In this study, we investigated bone mineral deficits in children who survived childhood acute leukemia and explored the association between the insulin-like growth factor-1 (IGF-1) level and bone mineral density (BMD). This retrospective analysis enrolled 214 patients treated for acute leukemia, measuring various factors including height, weight, body mass index (BMI), and lumbar spine BMD after the end of treatment. The study found an overall prevalence of low BMD in 15% of participants. Notably, IGF-1 levels were significantly different between patients with low BMD and those with normal BMD, and correlation analyses revealed associations of the IGF-1 level and BMI with lumbar spine BMD. Regression analyses further supported this relationship, suggesting that higher IGF-1 levels were associated with a decreased risk of low BMD. The study findings suggest that IGF-1 may serve as a valuable tool for evaluating and predicting osteoporosis in survivors of childhood acute leukemia.

We report a 4-year-old with Gorham–Stout disease (GSD) who was treated with a combination of bisphosphonate, sirolimus, and atenolol. A previously healthy 4-year-old girl presented with back pain after falling on her back 2 months prior. Thoracolumbar spine X-ray revealed diffuse compression spinal fractures in T9-L2. Magnetic resonance imaging (MRI) confirmed multiple compression fractures at T9-L5 and revealed a paraspinal mass along the T1-L1 level. Based on clinical, radiological, and histopathological findings, Gorham–Stout disease was diagnosed. Treatment with sirolimus (0.5 mg twice daily, 1.6 mg/m²) was initiated and intravenous bisphosphonate (pamidronate, 1 mg/kg for 3 days, total 3 mg/kg every 4 months) was added for back pain; she had immediate improvement in back pain. After 9 months with this treatment, she had a mild increase in paraspinal lymphangiomatosis and aggravation in T9-L5 compression fractures; atenolol was administered. The patient underwent 11 months of combination treatment with bisphosphonate, sirolimus, and atenolol, and MRI showed mild degree of reduction in the paraspinal lesions at L1-L5. The patient is currently in stable condition with no back pain or side effects. The triple combination treatment with bisphosphonate, sirolimus, and atenolol may be helpful in stabilizing the disease course of GSD.

We conducted a retrospective study on 51 pediatric patients with newly diagnosed chronic myeloid leukemia chronic phase or accelerated phase. The patients were classified into the IMA group (N = 33), treated with imatinib, and the DSA group (N = 18), treated with dasatinib, as front-line tyrosine kinase inhibitors (TKIs). At 12 months, the rates of complete cytogenetic response were similar between the IMA group (92.3%) and DSA group (100%) (p = 0.305). However, the rate of early molecular response was higher in the DSA group than in the IMA group (100.0% vs. 80.0%, p = 0.043). By 12 and 24 months, the DSA group showed faster and higher cumulative rates of both major (DSA group: 72.2% and 100%, respectively; IMA group: 41.2% and 68.7%, respectively; p = 0.002) and deep molecular responses (DSA group: 26.0% and 43.6%, respectively; IMA group: 13.8% and 17.5%, respectively; p = 0.004). Both TKIs were well tolerated. Although the height standard deviation scores decreased in both groups, the height decline was greater in the DSA group between one and two years from the start of TKI therapy. In this study, dasatinib achieved faster and higher molecular responses with an acceptable safety profile. Further follow-up is necessary to assess the long-term outcomes of TKI treatment in children.

Jae Won Yoo. CPHO 2023;30:1-10. https://doi.org/10.15264/cpho.2023.30.1.1