Objective:To evaluate the heterogeneity in pediatric ETV6-RUNX1 acute lymphoblastic leukemia (ALL) by gene expression profile and to study clinical characteristics in different clusters.Methods:An improved advanced fragment analysis (iAFA) technique was developed to detect 57 marker genes in 264 pediatric ALL patients treated in Beijing Children’s Hospital from August 2016 to June 2019. The 56 ALL patients with ETV6-RUNX1 positive were evaluated by clinical characteristics in gene expression profile, immunophenotype and early response of chemotherapy in different clusters.Results:The 56 ETV6-RUNX1-positive patients were clustered into 2 groups of E/R-1 (45, 80.4%) and E/R-2 (11, 19.6%) . Spearman coefficient was 0.788 and 0.901 in E/R-2 and E/R-1, respectively. The median of initial platelet counts was 104 (27-644) and 50 (8-390) ( P<0.01) in E/R-2 and E/R-1, respectively. The median of proportion of initial bone marrow immature cells was 0.830 (0.270-0.975) and 0.935 (0.445-0.990) ( P<0.05) in E/R-2 and E/R-1, respectively. The most specific immunophenotype at initial diagnosis, CD22 +CD34 +CD20 -CD117 -CD56 -, mainly gathered in E/R-2 ( P<0.001) . Patients negative of minimal residual disease detected by flow cytometry (MRD-FCM) at day 33 were 5 (55.6%) and 32 (88.9%) in E/R-2 and E/R-1, respectively. There was no significant difference in the original analysis ( P=0.064) but difference in sensitivity analysis ( P=0.035) . Nevertheless, patients negative of MRD detected by polymerase chain reaction (MRD-PCR) at day 33 were 7 (77.8%) and 36 (100%) in E/R-2 and E/R-1, respectively, with significant difference ( P=0.047) . Conclusion:Gene expression profile shows heterogeneous in ETV6-RUNX1 ALL, and the E/R-2 profile indicates that these patients may have a less tendency to thrombocytopenia at the initial diagnosis but have poorer response to induction chemotherapy and may influence further outcome.

Age-associated changes in immune cells have been linked to an increased risk for infection. However, a global and detailed characterization of the changes that human circulating immune cells undergo with age is lacking. Here, we combined scRNA-seq, mass cytometry and scATAC-seq to compare immune cell types in peripheral blood collected from young and old subjects and patients with COVID-19. We found that the immune cell landscape was reprogrammed with age and was characterized by T cell polarization from naive and memory cells to effector, cytotoxic, exhausted and regulatory cells, along with increased late natural killer cells, age-associated B cells, inflammatory monocytes and age-associated dendritic cells. In addition, the expression of genes, which were implicated in coronavirus susceptibility, was upregulated in a cell subtype-specific manner with age. Notably, COVID-19 promoted age-induced immune cell polarization and gene expression related to inflammation and cellular senescence. Therefore, these findings suggest that a dysregulated immune system and increased gene expression associated with SARS-CoV-2 susceptibility may at least partially account for COVID-19 vulnerability in the elderly.
Adult ; Aged ; Aged, 80 and over ; Aging ; genetics ; immunology ; Betacoronavirus ; CD4-Positive T-Lymphocytes ; metabolism ; Cell Lineage ; Chromatin Assembly and Disassembly ; Coronavirus Infections ; immunology ; Cytokine Release Syndrome ; etiology ; immunology ; Cytokines ; biosynthesis ; genetics ; Disease Susceptibility ; Flow Cytometry ; methods ; Gene Expression Profiling ; Gene Expression Regulation, Developmental ; Gene Rearrangement ; Humans ; Immune System ; cytology ; growth & development ; immunology ; Immunocompetence ; genetics ; Inflammation ; genetics ; immunology ; Mass Spectrometry ; methods ; Middle Aged ; Pandemics ; Pneumonia, Viral ; immunology ; Sequence Analysis, RNA ; Single-Cell Analysis ; Transcriptome ; Young Adult