IntroductionRecent advances in genetic analysis have led to the discovery of novel genetic subtypes of precursor B‐cell acute lymphoblastic leukemia (B‐ALL) with prognostic relevance. In this study, we studied a cohort of pediatric B‐ALL patients to retrospectively determine the incidence of patients harboring novel genetic subtypes, as well as their outcome.MethodsB‐ALL patients (N = 190) diagnosed in a single Korean hospital were included in the study. Patients' medical records were reviewed for data on established genetic abnormalities and outcome. CRLF2 expression was analyzed by quantitative RT‐PCR. Anchored multiplex PCR‐based enrichment was used to detect fusions and point mutations in 81 ALL‐related genes.ResultsIncidence of established recurrent genetic subtypes was as follows: high hyperdiploidy (21.6%), ETV6‐RUNX1 (21.6%), BCR‐ABL1 (7.9%), KMT2A rearrangement (7.4%) TCF3‐PBX1/TCF3‐HLF (7.4%), and hypodiploidy (1.1%). Incidence of new genetic subtypes was as follows: BCR‐ABL1‐like (13.2%), ETV6‐RUNX1‐like (2.1%), EWSR1‐ZNF384 (1.1%), and iAMP21 (1.1%). Median age at diagnosis of BCR‐ABL1‐like ALL was 6.8 years. According to type of genetic abnormality, BCR‐ABL1‐like ALL was divided into ABL class (12%), CRLF2 class (8%), JAK‐STAT class (12%), and RAS class (68%). The 5‐year event‐free survival (EFS) of BCR‐ABL1‐like patients was significantly inferior to non‐BCR‐ABL1‐like low‐ and standard‐risk patients (71.5 ± 9.1% vs 92.5 ± 3.2%, P = .001) and comparable to non‐BCR‐ABL1‐like high (75.2 ± 6.2%) and very high‐risk patients (56.8 ± 7.4%). All four ETV6‐RUNX1‐like patients survived event‐free.ConclusionAnalogous to previous studies, incidence of BCR‐ABL1‐like ALL in our cohort was 13.2% with outcome comparable to high and very high‐risk patients. A significantly high number of RAS class mutations was a distinct feature of our BCR‐ABL1‐like ALL group.

Conventional methods for etiologic diagnoses of acute gastroenteritis (AGE) are time consuming and have low positive yield leading to limited clinical value. This study aimed to investigate quality improvements in patient management, antibiotic stewardship, and in-hospital infection transmission prevention using BioFire® FilmArray® Gastrointestinal Panel (GI Panel) in children with acute diarrhea. This was a prospective study recruiting children <19 years old with new onset diarrhea during the study period, and a matched historical cohort study of children diagnosed with AGE during the 4 years prior. Patients in the prospective cohort underwent stool testing with GI Panel and conventional methods. A total of 182 patients were included in the prospective cohort, of which 85.7% (n = 156) had community-onset and 14.3% (n = 26) had hospital-onset diarrhea. A higher pathogen positivity rate for community-onset diarrhea was observed by the GI Panel (58.3%, n = 91) compared to conventional studies (42.3%, n = 66) (p = 0.005) and historical cohort (31.4%, n = 49) (p < 0.001). The stool tests reporting time after admission was 25 (interquartile range, IQR 17–46) hours for the GI Panel, and 72 (IQR 48–96) hours for the historical cohort (p < 0.001). A significant reduction in antibiotic use was observed in the prospective cohort compared to historical cohort, 35.3% vs. 71.8%; p < 0.001), respectively. Compared to the GI Panel, norovirus ICT was only able to detect 4/11 (36.4%) patients with hospital-onset and 14/27 (51.8%) patients with community-onset diarrhea. The high positivity rate and rapid reporting time of the GI Panel had clinical benefits for children admitted for acute diarrhea, especially by reducing antibiotic use and enabling early adequate infection precaution and isolation.

BackgroundEnterococcus faecium, especially vancomycin-resistant E. faecium (VREfm), is a major concern for patients with hematologic diseases. Exposure to antibiotics including fluoroquinolone, which is used as a routine prophylaxis for patients with hematologic (MH) diseases, has been reported to be a risk factor for infection with vancomycin-resistant eneterocci. We compared the characteristics of E. faecium isolates according to their vancomycin susceptibility and patient group (MH vs non-MH patients).MethodsA total of 120 E. faecium bacteremic isolates (84 from MH and 36 from non-MH patients) were collected consecutively, and their characteristics (susceptibility, multilocus sequence type [MLST], Tn1546 type, and the presence of virulence genes and plasmids) were determined.ResultsAmong the vancomycin-susceptible E. faecium (VSEfm) isolates, resistance to ampicillin (97.6% vs 61.1%) and high-level gentamicin (71.4% vs 38.9%) was significantly higher in isolates from MH patients than in those from non-MH patients. Notably, hyl, esp, and pEF1071 were present only in isolates with ampicillin resistance. Among the VREfm isolates, ST230 (33.3%) and ST17 (26.2%) were predominant in MH patients, while ST17 (61.1%) was predominant in non-MH patients. Plasmid pLG1 was more prevalent in E. faecium isolates from MH patients than in those from non-MH patients, regardless of vancomycin resistance. Transposon analysis revealed five types across all VREfm isolates.ConclusionsThe antimicrobial resistance profiles and molecular characteristics of E. faecium isolates differed according to the underlying diseases of patients within the same hospital. We hypothesize that the prophylactic use of fluoroquinolone might have an effect on these differences.

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is associated with inferior outcomes in the chemotherapy setting. We hypothesized that allogeneic hematopoietic cell transplantation (allo-HCT)-based post-remission therapy would improve outcomes of this entity. We examined the frequency and long-term outcomes of adults with Ph-like ALL, particularly focusing on allo-HCT outcomes for Ph-like ALL versus non-Ph-like ALL. Ph-like ALL was determined by anchored multiplex PCR-based targeted next-generation sequencing. Of the 344 patients, 57 (16.6%) had Ph-like ALL, 197 (57.3%) had Ph-positive ALL, and 90 (26.1%) had B-other ALL. To further evaluate the prognosis of Ph-like ALL, outcome analyses were restricted to 147 patients, excluding Ph-positive ALL. The actual allo-HCT rates in complete remission were 87.7% for Ph-like ALL, 71.4% for B-other standard-risk ALL, and 70.4% for B-other poor-risk ALL. Patients with Ph-like ALL had a higher 5-year overall survival (60.6% vs 27.1%; P = 0.008) than B-other poor-risk ALL subgroup, while no difference was observed compared with B-other standard-risk ALL subgroup. Similar results were noted in a separate analysis for patients receiving allo-HCT in complete remission. In multivariate analyses, B-other poor-risk ALL was associated with poorer outcomes. Our data showed that allo-HCT-based post-remission therapy may have contributed to non-inferior outcomes of adult Ph-like ALL.