Abstract We first described the 2019 novel coronavirus infection in 10 children occurring in areas other than Wuhan. The coronavirus diseases in children are usually mild and epidemiological exposure is a key clue to recognize pediatric case. Prolonged virus shedding is observed in respiratory tract and feces at the convalescent stage.

Purpose: The transcription factor CCAAT/enhancer binding protein A, encoded by the CEBPA, is crucial for the differentiation of immature granulocytes. Mutation of the CEBPA may play an important role in leukemogenesis and prognosis. We sought to characterize the CEBPA mutation in acute myeloid leukemia (AML) and to clarify if there is a distinct immunophenotype for leukemic cells with the mutation.Experiment Design: One hundred and four patients with de novo AML were evaluated for the CEBPA mutation and immunophenotype of the leukemic cells.Results: Twenty-two distinct mutations were identified in 16 (15%) of 104 AML patients. Fourteen patients had biallelic mutations, mostly involving both the NH 2 -terminal TAD1 region and the COOH-terminal basic leucine zipper domain (bZIP). The mutations in the bZIP region were always tandem duplications and were located at hot-spot regions for topoisomerase II sites. Sequential study of the CEBPA mutations showed that the mutations disappeared at complete remission but the same mutations reappeared at relapse. None of the patients developed novel mutations during the follow-up period. Patients with CEBPA mutations had significantly higher incidences of CD7 (73%), CD15 (100%), CD34 (93%), and HLA-DR (93%) expression on the leukemic cells.Conclusion: These data revealed that most AML with CEBPA mutations were associated with an immunophenotype of HLA-DRThe close relationship of CEBPA mutations with the leukemia status of the patients and the concordance of mutation in presenting and relapse samples implicate the CEBPA mutation as a potential marker for monitoring minimal residue disease.

Nucleophosmin (NPM) mutations have been found in a significant proportion of adults with de novo acute myeloid leukemia (AML), especially in those of a normal karyotype. These results provide a basis for studies of the pathogenesis in this specific subgroup of AML. In this study, NPM mutations were analyzed in 173 Chinese patients of de novo AML, including adults and children. We found that NPM mutations were present in 19.1% of the overall population and 40.3% of those with a normal karyotype. Adults had a significantly higher incidence of NPM mutations than children [32 of 126 (25.4%) versus 1 of 47 (2.1%), P < 0.001]. NPM mutations were closely associated with normal karyotype (P < 0.001) and internal tandem duplication of FLT3 (P = 0.002), but negatively associated with CEBPA mutations (P = 0.032) and expression of CD34 (P < 0.001) and HLA-DR (P = 0.003). Serial analyses of NPM mutations showed the mutation disappeared at complete remission, but the same mutation reappeared at relapse, except for one who lost the mutation at the second relapse, when new cytogenetic abnormalities emerged. None acquired novel mutations during the follow-up period. In conclusion, NPM mutations occur in an age-dependent fashion. Moreover, the findings that NPM mutations are stable during disease evolution and closely associated with disease status make it a potential marker for monitoring minimal residual disease. (Cancer Res 2006; 66(6): 3310-6)

Purpose: To investigate the possible prognostic factors of survival outcomes in patients with granulocytic sarcoma (GS). Methods: We retrospectively investigated the prognostic factors determining survival in 24 patients with GS using Kaplan-Meier survival analysis followed by log rank tests. We evaluated gender, age, location, GS antedating leukemia, underlying disorders, treatment type and stem cell transplantation. Results: The 5-year survival rate for the patients with GS was 21%. The patients undergoing chemotherapy had a significantly longer survival time compared to those who did not (p = 0.0009). We found no difference in the 5-year survival rate among the patients undergoing chemotherapy combined with radiation or surgery. Patients with chronic myelogenous leukemia and myelodysplastic disorders had worse survival rates (p = 0.0028). Conclusion: Early diagnosis with biopsy and early chemotherapy can improve survival outcome. Local radiation or surgery can improve symptoms but does not influence survival outcomes.

Summary CD4+ CD25+ regulatory T cells (Tregs) are critical in maintaining self‐tolerance and preventing organ‐specific autoimmunity. Their role in paediatric systemic lupus erythematosus (SLE), an autoimmune disease characterized by inappropriate regulation of hyperactivated B and T cells, has not been clearly defined. Using flow cytometry to determine cell populations and real‐time polymerase chain reaction to assay mRNA expression for FOXP3, CTLA‐4, and GITR, we characterized CD4+ CD25+ T cells in paediatric SLE patients and healthy subjects. The frequency of CD4+ CD25+ Tregs was significantly decreased in patients with active SLE compared with patients with inactive SLE and with controls (7·27% ± 2·50%, 9·59% ± 2·80% and 9·78% ± 2·11%, respectively; P = 0·027 and P < 0·001, respectively), and was inversely correlated with disease activity, as assessed with the Systemic Lupus Erythematosus Disease Activity Index 2000 scores (r = −0·59, P = 0·001) and serum anti‐double‐stranded DNA levels (r = −0·65, P < 0·001). Our preliminary investigations found elevated surface expression of GITR in CD4+ CD25+ T cells, elevated mRNA expression of CTLA‐4 in CD4+ T cells and higher amounts of mRNA expression for FOXP3 in CD4+ cells in patients with active SLE compared with patients with inactive disease and controls. We demonstrated reduced CD4+ CD25+ Treg levels were inversely correlated with disease activity, indicating a defective Treg population in paediatric SLE patients. The differences in the expression of FOXP3, CTLA‐4 and GITR imply the possible role of CD4+ Tregs in the pathogenesis of SLE.

Prolonged exposure to thiopurines (eg, mercaptopurine [MP]) is essential for curative therapy in acute lymphoblastic leukemia (ALL), but is also associated with frequent dose-limiting hematopoietic toxicities, which is partly explained by inherited genetic polymorphisms in drug metabolizing enzymes (eg, ). Recently, our group and others identified germ line genetic variants in as another major cause of thiopurine-related myelosuppression, particularly in Asian and Hispanic people. In this article, we describe 3 novel coding variants (p.R34T, p.K35E, and p.G17_V18del) in 5 children with ALL enrolled in frontline protocols in Singapore, Taiwan, and at St. Jude Children's Research Hospital. Patients carrying these variants experienced significant toxicity and reduced tolerance to MP across treatment protocols. Functionally, all 3 variants led to partial to complete loss of NUDT15 nucleotide diphosphatase activity and negatively influenced protein stability. In particular, the p.G17_V18del variant protein showed extremely low thermostability and was completely void of catalytic activity, thus likely to confer a high risk of thiopurine intolerance. This in-frame deletion was only seen in African and European patients, and is the first risk variant identified in non-Asian, non-Hispanic populations. In conclusion, we discovered 3 novel loss-of-function variants in associated with MP toxicity, enabling more comprehensive pharmacogenetics-based thiopurine dose adjustments across diverse populations.

Despite current risk-directed therapy, approximately 15-20% of pediatric patients with acute lymphoblastic leukemia (ALL) have relapses. Recent genome-wide analyses have identified that an alteration of IKZF1 is associated with very poor outcomes in B-cell progenitor ALL. In this study, we determined the prognostic significance of IKZF1 deletions in patients with childhood ALL. This study analyzed 242 pediatric B-cell progenitor ALL patients in Taiwan. We developed a simple yet sensitive multiplex quantitative PCR coupled with capillary electrophoresis to accurately determine the allele dose of IKZF1, and high resolution melting was used for mutation screening for all coding exons of IKZF1. Twenty-six (10.7%) pediatric B-cell progenitor ALL patients were found to harbor these deletions. Most of the deletions were broader deletions that encompassed exon 3 to exon 6, consistent with previous reports. Genomic sequencing of IKZF1 was carried out in all cases and no point mutations were identified. Patients with IKZF1 deletions had inferior event-free survival (P < 0.001), and overall survival (P = 0.0016). The association between IKZF1 deletions and event-free survival was independent of age, leukocyte count at presentation, and cytogenetic subtype by multivariate Cox analysis (P = 0.003, hazard ratio = 2.45). This study indicates that detection of IKZF1 deletions upon diagnosis of B-cell progenitor ALL may help to identify patients at risk of treatment failure. IKZF1 deletions could be incorporated as a new high-risk prognostic factor in future treatment protocols. To the best of our knowledge, this is the first study to examine the poor prognosis of IKZF1 deletions in an Asian population.

The long-term outcome of 1390 children with acute lymphoblastic leukemia (ALL), treated in two successive clinical trials (Taiwan Pediatric Oncology Group (TPOG)-ALL-97 and TPOG-ALL-2002) between 1997 and 2007, is reported. The event-free survival improved significantly (P ¼ 0.0004) over this period, 69.3±1.9% in 1997-2001 to 77.4±1.7% in 2002-2007. A randomized trial in TPOG-97 testing L-asparaginase versus epidoxorubicin in combination with vincristine and prednisolone for remission induction in standard-risk (SR; low-risk) patients yielded similar outcomes. Another randomized trial, in TPOG-2002, showed that for SR patients, two reinduction courses did not improve long-term outcome over one course. Decreasing use of prophylactic cranial irradiation in the period 1997-2008 was not associated with increased rates of CNS relapse, prompting complete omission of prophylactic cranial irradiation from TPOG protocols, beginning in 2009. Decreased use of etoposide and cranial irradiation likely contributed to the low incidence of second cancers. High-risk B-lineage ALL, T-cell, CD10 negativity, t(9;22), infant, and higher leukocyte count were consistently adverse factors, whereas hyperdiploidy 450 was a consistently favorable factor. Higher leukocyte count and t(9;22) retained prognostic significance in both TPOG-97 and TPOG-2002 by multivariate analysis. Although long-term outcome in TPOG clinical trials is comparable with results being reported worldwide, the persistent strength of certain prognostic variables and the lower frequencies of favorable outcome predictors, such as ETV6-RUNX1 and hyperdiploidy 450, in Taiwanese children warrant renewed effort to cure a higher proportion of patients while preserving their quality of life.