Early Detection of Molecular Residual Disease and Risk Stratification for Children with Acute Myeloid Leukemia via Circulating Tumor DNA.

PURPOSE: Patient-tailored minimal residual disease (MRD) monitoring based on circulating tumor DNA (ctDNA) sequencing of leukemia-specific mutations enables early detection of relapse for pre-emptive treatment, but its utilization in pediatric acute myelogenous leukemia (AML) is scarce. Thus, we aim to examine the role of ctDNA as a prognostic biomarker in monitoring response to the treatment of pediatric AML. EXPERIMENTAL DESIGN: A prospective longitudinal study with 50 children with AML was launched, and sequential bone marrow (BM) and matched plasma samples were collected. The concordance of mutations by next-generation sequencing-based BM-DNA and ctDNA was evaluated. In addition, progression-free survival (PFS) and overall survival (OS) were estimated. RESULTS: In 195 sample pairs from 50 patients, the concordance of leukemia-specific mutations between ctDNA and BM-DNA was 92.8%. Patients with undetectable ctDNA were linked to improved OS and PFS versus detectable ctDNA in the last sampling (both P < 0.001). Patients who cleared their ctDNA post three cycles of treatment had similar PFS compared with persistently negative ctDNA (P = 0.728). In addition, patients with >3 log reduction but without clearance in ctDNA were associated with an improved PFS as were patients with ctDNA clearance (P = 0.564). CONCLUSIONS: Thus, ctDNA-based MRD monitoring appears to be a promising option to complement the overall assessment of pediatric patients with AML, wherein patients with continuous ctDNA negativity have the option for treatment de-escalation in subsequent therapy. Importantly, patients with >3 log reduction but without clearance in ctDNA may not require an aggressive treatment plan due to improved survival, but this needs further study to delineate.

[Prevalence and risk factors of obesity in children with Diamond-Blackfan anemia]. / å ˆå¤©æ€§çº¯çº¢ç»†èƒžå†ç”Ÿéšœç¢æ€§è´«è¡€æ‚£å„¿è‚¥èƒ–å‘ç”Ÿæƒ å†µåŠå½±å“å› ç´ åˆ†æž.

OBJECTIVES: To investigate the distribution of body mass index (BMI) and risk factors for obesity in children with Diamond-Blackfan Anemia (DBA). METHODS: The children with DBA who attended National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, from January 2003 to December 2020 were enrolled as subjects. The related clinical data and treatment regimens were recorded. The height and weight data measured within 1 week before or after follow-up time points were collected to calculate BMI. The risk factors for obesity were determined by multivariate regression analysis in children with DBA. RESULTS: A total of 129 children with DBA were enrolled, among whom there were 80 boys (62.0%) and 49 girls (38.0%), with a median age of 49 months (range 3-189 months). The prevalence rate of obesity was 14.7% (19/129). The multivariate logistic regression analysis showed that the absence of ribosomal protein gene mutation was closely associated with obesity in children with DBA (adjusted OR=3.63, 95%CI: 1.16-11.38, adjusted P=0.027). In children with glucocorticoid-dependent DBA, obesity was not associated with age of initiation of glucocorticoid therapy, duration of glucocorticoid therapy, and maintenance dose of glucocorticoids (P>0.05). CONCLUSIONS: There is a high prevalence rate of obesity in children with DBA, and the absence of ribosomal protein gene mutation is closely associated with obesity in children with DBA.

Significance of paroxysmal nocturnal hemoglobinuria clone in immunosuppressive therapy for children with severe aplastic anemia. / é˜µå‘æ€§ç¡çœ æ€§è¡€çº¢è›‹ç™½å°¿å ‹éš†åœ¨å„¿ç«¥é‡åž‹å†ç”Ÿéšœç¢æ€§è´«è¡€å ç–«æŠ‘åˆ¶æ²»ç–—ä¸­çš„æ„ä¹‰.

OBJECTIVES: To study the association between paroxysmal nocturnal hemoglobinuria (PNH) clone and immunosuppressive therapy (IST) in children with severe aplastic anemia (SAA). METHODS: A retrospective analysis was performed on the medical data of 151 children with SAA who were admitted and received IST from January 2012 to May 2020. According to the status of PNH clone, these children were divided into a negative PNH clone group (n=135) and a positive PNH clone group (n=16). Propensity score matching was used to balance the confounding factors, and the impact of PNH clone on the therapeutic effect of IST was analyzed. RESULTS: The children with positive PNH clone accounted for 10.6% (16/151), and the median granulocyte clone size was 1.8%. The children with positive PNH clone had an older age and a higher reticulocyte count at diagnosis (P<0.05). After propensity score matching, there were no significant differences in baseline features between the negative PNH clone and positive PNH clone groups (P>0.05). The positive PNH clone group had a significantly lower overall response rate than the negative PNH clone group at 6, 12, and 24 months after IST (P<0.05). The evolution of PNH clone was heterogeneous after IST, and the children with PNH clone showed an increase in the 3-year cumulative incidence rate of aplastic anemia-PNH syndrome (P<0.05). CONCLUSIONS: SAA children with positive PNH clone at diagnosis tend to have poor response to IST and are more likely to develop aplastic anemia-PNH syndrome.