[Effect of Low-Dose Recombinant Interleukin-2 Therapy on Immunocyte Subsets in Children with Solid Tumor].

OBJECTIVE: To evaluate the effect of low-dose recombinant interleukin-2 (rIL-2) therapy on immunocyte subsets and its side effects in children with solid tumor. METHODS: A total of 22 children (11 males and 11 females) with solid tumor in our department from December 2012 to November 2017 were selected, with a median age of 9 (3-16) years old when starting IL-2 therapy. ALL surgeries and chemotherapy of children had been completed before low-dose rIL-2 therapy, and 17 cases achieved complete remission (CR) and 5 cases achieved partial remission (PR). A low-dose rIL-2 therapy was given 1 month after chemotherapy for 1 year: 4×105 IU/(m2·d), s.c. for every other day, 3 times per week. The immunocyte subsets were detected every 3 months until the end of treatment, meanwhile, disease condition and therapy-related side effects were followed up. RESULTS: After low-dose rIL-2 therapy in 22 children, the absolute values of CD3+ T cells, CD3-CD56+ natural killer cells, CD3+CD4+ helper T cells (Th) and CD3+CD8+ cytotoxic T cells were up-regulated remarkably, as well as Th/suppressor T cells (all P < 0.05). While, there were no significant differences in absolute value and proportion of CD4+CD25+CD127- Treg cells during therapy. Among the 17 children who achieved CR before rIL-2 therapy, 14 cases continued to maintain CR after therapy, while 3 cases relapsed, and with 2 died after treatment abandonment. The 5 children who achieved PR before low-dose rIL-2 therapy were evaluated CR by PET/CT scan after treatment. In the early stage of low-dose rIL-2 therapy, 1 child developed skin rashes at the injection sites, and 2 children ran a slight to mild transient fever. Their symptoms disappeared without any organ damage after symptomatic treatment. CONCLUSION: Low-dose rIL-2 therapy has good drug tolerance, and changes the distribution of anti-tumor immune-cell subgroup in peripheral blood of children with solid tumor remarkably without up-regulation of absolute value and ratio of Treg cells.

The RAS-signaling-pathway-mutation-related prognosis in B-cell acute lymphoblastic leukemia: A report from South China children's leukemia group.

The next-generation sequencing technologies application discovers novel genetic alterations frequently in pediatric acute lymphoblastic leukemia (ALL). RAS signaling pathway mutations at the time of relapse ALL frequently appear as small subclones at the time of onset, which are considered as the drivers in ALL relapse. Whether subclones alterations in the RAS signaling pathway should be considered for risk group stratification of ALL treatment is not decided yet. In this work, we investigate the RAS signaling pathway mutation spectrum and the related prognosis in pediatric ALL. We employed an NGS panel comprising 220 genes. NGS results were collected from 202 pediatric ALL patients. 155 patients (76.7%) harbored at least one mutation. The incidences of RAS signaling pathway mutations are different significantly between T-ALL and B-ALL. In B-ALL, the RAS pathway is mostly involved, and NRAS (17.6%), KRAS (22.7%), and PTPN11 (7.7%) were the three most frequently mutated genes. Co-occurring mutations of CREBBP and NRAS, FLT3, or PTPN11 (p = 0.002, p = 0.009, and p = 0.003, respectively) were found in this cohort. The 3-year RFS rates for the RAS signaling pathway mutation-positive and negative cases was 76.5 % versus 89.7 % (p = 0.012). Four cases relapsed in the lately 3 years were RAS signaling pathway mutation-positive. RAS signaling pathway mutation is an important biomarker for poorer relapse-free survival in pediatric B-ALL patients despite good early MRD levels.

Local Treatment of Children Suffering From Parameningeal Rhabdomyosarcoma: A Retrospective Single-Center Study From China.

BACKGROUND: Treatment for parameningeal rhabdomyosarcoma (PM-RMS) has been a challenge since local control is difficult. The goal of this study was to analyse the impact of different local treatment approaches on childhood PM-RMS patients and help dispel the doubt that whether secondary radical surgery (SRS) should be encouraged in the management of PM-RMS. METHODS: A total of 17 children with PM-RMS who received unified systemic chemotherapy and individualized local therapy such as radiotherapy (RT) and/or SRS were included in this retrospective study. The overall survival (OS) and event free survival (EFS) were compared between groups adopting different local strategies. RESULTS: The 3-year OS and EFS of our PM-RMS patients was 75.5% and 56.5% respectively. The OS and EFS of patients who received SRS were both significantly lower than that of the non-SRS group (3-year OS: 50.0% vs 90.0%, P = .031; 3-year EFS: 33.3% vs 60.6%, P = .020). The OS and EFS of the patients who received RT was higher than that of the patients of the non-RT group (3-year OS: 85.6% vs 0%, P = .001; 3-year EFS: 64.0% vs 0%, P = .011). CONCLUSION: This study illustrates that SRS was associated with poor prognosis of PM-RMS and should not be routinely performed. Optimized RT strategies along with more intensive chemotherapy may be alternative options to improve the survival of patients with PM-RMS. Multi-center, large sample and prospective studies are needed to further validate these findings.

Prognostic scoring system for pediatric Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis based on baseline characteristics: A multicenter retrospective study.

BACKGROUND: The prognosis of pediatric Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (EBV-HLH) varies. This study aimed to identify high-risk children early. PROCEDURE: Data from 264 children (0-14 years of age), diagnosed with EBV-HLH at six centers in China between January 2016 and December 2021, were analyzed. Patients were randomly divided into derivation (n = 185) and verification (n = 79) cohorts. A Cox regression model was used to explore risk predictors and establish a prognostic scoring system for death events that occurred during the follow-up period. RESULTS: Chronic active EBV infection (CAEBV) history (hazard ratio [HR] 1.82 [95% confidence interval, CI: 1.02-3.26]; p = .0441), plasma EBV-DNA more than 104  copies/mL (HR 2.89 [95% CI: 1.62-5.16]; p = .0003), pulmonary infection (HR 2.24 [95% CI: 1.06-4.75]; p = .0353), digestive tract hemorrhage (HR 2.55 [95% CI: 1.35-4.82]; p = .0041), and hypoxemia (HR 3.95 [95% CI: 2.15-7.26]; p < .0001) were independent risk factors. Accordingly, the CAEBV history, plasma EBV-DNA copy number, pulmonary infection hemorrhage of digestive tract, hypoxemia prognostic scoring system (CEPHO-PSS) were developed, which separated patients into low- (0-1 points), middle- (2-3 points), and high- (4-8 points) risk groups. Survival curves for the three groups exhibited statistically significant differences (p < .0001). Internal and external verification of CEPHO-PSS was performed using receiver operating characteristic (ROC) and calibration curves in the derivation and verification cohorts, respectively, confirming good accuracy and applicability. CONCLUSIONS: The CEPHO-PSS identified three risk groups with statistically significant differences in survival curves. It was based on the baseline characteristics, and can give clinicians a convenient check for risk prediction.

Long-term outcome of children with acute promyelocytic leukemia: a randomized study of oral versus intravenous arsenic by SCCLG-APL group.

Realgar-Indigo naturalis formula (RIF), an oral traditional Chinese medicine mainly containing Realgar (As4S4), is highly effective in treating adult acute promyelocytic leukemia (APL). However, the treatment efficacy and safety of RIF have not been verified in pediatric patients. SCCLG-APL group conducted a multicenter randomized non-inferiority trial to determine whether intravenous arsenic trioxide (ATO) can be substituted by oral RIF in treating pediatric APL. Of 176 eligible patients enrolled, 91 and 85 were randomized to ATO and RIF groups, respectively. Patients were treated with the risk-adapted protocol. Induction, consolidation, and 96-week maintenance treatment contained all-trans-retinoic acid and low-intensity chemotherapy, and either ATO or RIF. The primary endpoint was 5-year event-free survival (EFS). The secondary endpoints were adverse events and hospital days. After a median 6-year follow-up, the 5-year EFS was 97.6% in both groups. However, the RIF group had significantly shorter hospital stays and lower incidence of infection and tended to have less cardiac toxicity. All 4 relapses occurred within 1.5 years after completion of maintenance therapy. No long-term arsenic retentions were observed in either group. Substituting oral RIF for ATO maintains treatment efficacy while reducing hospitalization and adverse events in treating pediatric APL patients, which may be a future treatment strategy for APL.

Coexistence of ETV6-RUNX1 and MLL aberration among pediatric acute lymphoblastic leukemia: case reports and a literature review.

Background: It is known that ETV6-RUNX1 is usually related to favorable prognosis, but MLL aberration has been associated with poor prognosis among pediatric acute lymphoblastic leukemia (ALL). However, the outcome of coexistence of ETV6-RUNX1 and MLL aberration in pediatric ALL patients is unknown. Herein, we report 4 cases of the coexistence of ETV6-RUNX1 and MLL-partial tandem duplications (MLL-PTD) in pediatric ALL patients and show the favorable outcome, which was never reported before. Case Description: The frequency of coexistence of ETV6-RUNX1 and MLL aberration at our children's medical center was calculated as 0.98% (4/410). All of them were ETV6/RUNX1-positive cases that exhibited MLL-PTD, and the 10-year event-free survival (EFS) and overall survival (OS) were both 75%. With the following keywords of "ETV6-RUNX1", "MLL", "children" and "acute lymphoblastic leukemia", a literature search of coexistence of ETV6-RUNX1 and MLL aberration was conducted in the database of PubMed, and 4 articles were retrieved finally, involving 16 cases of children. Among the 16 cases of pediatric ALL, the age ranged from 2 to 7 years old, including 9 males and 7 females and the white blood cell (WBC) count was (2.66-68.6)×109/L. In terms of fusion genes, they all had positive ETV6/RUNX1. Among them, MLL deletion was exhibited among 8 ETV6/RUNX1-positive patients, and 2 cases of der(21) duplication. MLL allelic deletions were shown among the remaining ETV6/RUNX1-positive patients. All patients showed a favorable outcome. Conclusions: The results of our analysis primarily provide compelling evidence that cases with an MLL-PTD or other types of MLL aberration are in fact a distinct subentry among ETV6-RUNX1 B-cell ALL (B-ALL).

Arsenic Trioxide inhibits Activation of Hedgehog Pathway in Human Neuroblastoma Cell Line SK-N-BE(2) Independent of Itraconazole.

BACKGROUND: Neuroblastoma (NB) remains associated with a low overall survival rate over the long term. Abnormal activation of the Hedgehog (HH) signaling pathway can activate the transcription of various downstream target genes that promote NB. Both arsenic trioxide (ATO) and itraconazole (ITRA) can inhibit tumor growth. OBJECTIVE: To determine whether ATO combined with ITRA can be used to treat NB with HH pathway activation, we examined the effects of ATO and ITRA monotherapy or combined inhibition of the HH pathway in NB. METHODS: Analysis of CCK8 and flow cytometry showed cell inhibition and cell cycle, respectively. Real-time PCR analysis was conducted to assess the mRNA expression of HH pathway. RESULTS: We revealed that as concentrations of ATO and ITRA increased, the killing effects of both agents on SK-N-BE(2) cells became more apparent. During G2/M, the cell cycle was largely arrested by ATO alone and combined with ITRA, and in the G0/G1 phase by ITRA alone. In the HH pathway, ATO inhibited the transcription of the SHH, PTCH1, SMO and GLI2 genes, however, ITRA did not. Instead of showing synergistic effects in a combined mode, ITRA decreased ATO inhibitory effects. CONCLUSION: We showed that ATO is an important inhibitor of HH pathway but ITRA can weaken the inhibitory effect of ATO. This study provides an experimental evidence for the clinical use of ATO and ITRA in the treatment of NB with HH pathway activation in cytology.

Real-World Presentation and Prognostic Effect of Allogeneic Blood Transfusion during the Intensive Induction Phase in Pediatric Acute Lymphoblastic Leukemia.

Purpose: To determine associations between allogeneic blood transfusion (ABT) during the intensive induction phase of therapy and prognostic effect in a real-world cohort of pediatric patients with acute lymphoblastic leukemia (ALL). Methods: A total of 749 pediatric patients who were diagnosed with ALL were enrolled in this study by using a single-center retrospective cohort study method from February 2008 to May 2022. Results: Among the ABT patients, 711 (94.9%) children were transfused with packed red blood cells (PRBCs), 434 (57.9%) with single-donor platelets (SDPs), and 196 (26.2%) with fresh frozen plasma (FFP). Our multivariate analysis demonstrated that FFP transfusion was the unique independent factor that affected both relapse-free survival (RFS) and overall survival (OS). The transfusion of FFP was significantly associated with higher age (p < 0.001), being more likely to receive SCCLG-ALL-2016 protocol (p < 0.001), higher proportion of more than 25 blood product transfusions, more PRBC transfusion (p < 0.001), and higher D33-MRD-positive rates (p = 0.013). Generalized additive models and threshold effect analysis using piece-wise linear regression were applied to identify the cut-off value of 25 mL/kg for average FFP transfusion. K-M survival analysis further confirmed that average FFP transfusion > 25 mL/kg was an independent adverse indicator of inferior outcome in terms of RFS (p = 0.027) and OS (p = 0.033). Conclusions: In blood products, only FFP supplement is closely related to the prognosis of childhood ALL. During the intensive induction phase, the indications of FFP transfusion should be strictly grasped, and the total amount of FFP should be controlled and kept below 25 mL/kg.

[Relationship between MTHFR Gene Polymorphism(C677T) and Adverse Reactions of High-Dose Methotrexate in Pediatric Patients with Acute Lymphoblastic Leukemia].

OBJECTIVE: To explore the effects of methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism on the adverse reactions of high-dose methotrexate (MTX) in pediatric patients with acute lymphoblastic leukemia (ALL). METHODS: A total of 69 children with ALL admitted to the department of Pediatrics of Sun Yat-sen Memorial Hospital of Sun Yat-sen University from November 2018 to October 2020 were included in this study. The clinical data of the children were collected, leukocytes were isolated from their peripheral blood, and MTHFR genotyping was performed by digital fluorescence molecular hybridization techniques. The adverse reactions and plasma drug concentration of MTX were monitored during the chemotherapy. Moreover, the effect of MTHFR gene polymorphism on MTX adverse reactions and plasma drug concentration were analyzed. RESULTS: Among the middle and high risk children, compared with the wildtype group (CC genotype), patients with MTHFR C677T mutations (CT+TT genotypes) had a higher risk of leukopenia (OR=2.38), neutropenia (OR=2.2), anemia (OR=1.83) and hepatoxicity (OR=1.98). However, no significant difference was found in the MTX plasma concentration between the MTHFR C677T mutantion group and the wildtype group at different timepoints (24 h, 48 h and 72 h). Multivariate analysis revealed that the plasma concentration of MTX (48 h), clinical risk level of ALL and MTHFR C677T gene polymorphism were independent factors for the adverse reactions of high-dose MTX. CONCLUSION: The MTHFR C677T mutations may be associated with myelosuppression and hepatotoxicity in children with ALL after high-dose MTX treatment.

Ruxolitinib inhibits the proliferation and induces the apoptosis of MLL-r ALL cells through inactivating JAK/STAT signaling pathway.

Background: The childhood patients with mixed-lineage leukemia rearrangement (MLL-r) gene have worse outcome than non-MLL, and thus often treated with high-risk chemotherapy regimens, so targeted therapy is important for this type of leukemia. This purpose of study was to explore the effects of ruxolitinib on the proliferation, apoptosis, and cell cycle of Nalm-6 cells. Methods: In this study, human acute lymphoblastic leukemia (ALL) cell line Nalm-6 was used as the research object. By constructing an MLL overexpression vector to transfect Nalm-6 cells, exogenous JAK2/STAT3 signal pathway inhibitor ruxolitinib was applied to observe the proliferation, apoptosis, and cell cycle changes of the transfected Nalm-6 cells. Western blot was performed to determine the proteins (MLL-BP, JAK, STAT) involved in the mechanism of action of MLL-r leukemia. CCK8 assay and flow cytometry (FCM) were used for testing the proliferation and apoptosis among MLL-BP transfected Nalm-6 cells. Results: Firstly, we determine the IC50 of ruxolitinib on Nalm-6 cells. Secondly, FCM and CCK8 showed that ruxolitinib dosedependentlyinhibits proliferation of Nalm-6 cells by blocking the cell cycle at G0/G1 phase. In addition, FCM showed that ruxolitinib promoted the apoptosis of MLL-BP transfected Nalm-6 cells. Mechanistically, ruxolitinib inactivated JAK/STAT signaling pathway in MLL-BP transfected Nalm-6 cells, mediating ruxolitinib's inhibition of cell proliferation, and inducing apoptosis. Finally, ruxolitinib significantly inhibited the proliferation of MLL-r ALL cells and promoted their apoptosis. Conclusions: These data provide compelling evidence that ruxolitinib is a promising agent against MLL-r leukemia cell line. However, it needs going through multiple more steps to confirm before it can be an option in clinical practice.

Outcome and prognostic factors of CBF pediatric AML patients with t(8;21) differ from patients with inv(16).

PURPOSE: To explore the outcome and prognostic factors between inv(16) and t(8;21) disrupt core binding factor (CBF) in acute myeloid leukemia (AML). METHODS: The clinical characteristic, probability of achieving complete remission (CR), overall survival (OS) and cumulative incidence of relapse (CIR) were compared between inv(16) and (8;21). RESULTS: The CR rate was 95.2%, 10-year OS was 84.4% and CIR was 29.4%. Subgroup analysis showed that patients with t(8;21) had significant lower 10-year OS and CIR than patients with inv(16). Unexpectedly, there was a trend for pediatric AML receiving five courses cytarabine to have a lower CIR than four courses cytarabine (19.8% vs 29.3%, P = 0.06). Among the cohort of no-gemtuzumab ozogamicin(GO) treatment, inv (16) patients showed a similar 10-year OS (78.9% vs 83.5%; P = 0.69) and an inferior outcome on 10-year CIR (58.6% vs 28.9%, P = 0.01) than those patients with t(8;21). In contrast, inv (16) and t(8;21) patients receiving GO treatment had comparable OS (OS: 90.5% vs. 86.5%, P = 0.66) as well as CIR (40.4% vs. 21.4%, P = 0.13). CONCLUSION: Our data demonstrated that more cumulative cytarabine exposure could improve the outcome of childhood patients with t(8;21), while GO treatment was beneficial to the pediatric patients with inv(16).

Chidamide as maintenance after chemotherapy or hematopoietic stem cell transplantation in 27 children with T-cell lymphoblastic leukemia: A real-world prospective study.

Background: The long-term overall survival of children with T-cell acute lymphoblastic leukemia (T-ALL) is limited to approximately 80-85% because of a high incidence of relapse after achieving remission with intensive chemotherapy and hematopoietic stem cell transplantation (HSCT). Novel treatment strategies inducing long-term remission are needed to improve the outcome. Histone deacetylase inhibitors (HDACis) have been reported to be effective in a series of T-ALL cases. Preclinical studies suggested that T-ALL cells are sensitive to Chidamide, which is a selective HDACi. Methods: This preliminary clinical study evaluated the efficacy and safety of Chidamide in combination with chemotherapy or post-HSCT for children with T-ALL at a dose of 0.5 mg/kg weight of patient twice per week for at least 6 months. Results: In total, 27 children with a mean age of 7.88 years were included. The high-risk proportion was 66.7%. After a median follow-up period of 37.8 months (9.5-67.9 months), the overall survival and event-free survival in the patients treated with Chidamide were 94.1 and 95.2%, respectively. All patients except two maintained persistent remission with <0.01% blast cells in minimal residual disease. Conclusion: The combination therapy with Chidamide in a case series of T-ALL shows the promising clinical efficacy and good safety in children. Clinical trial registration: https://www.chictr.org.cn/, identifier ChiCTR2000030357.

Relationship between methylenetetrahydrofolate reductase gene polymorphisms and methotrexate drug metabolism and toxicity.

Background: Acute lymphoblastic leukemia (ALL) is the most common malignancy in children, and methotrexate (MTX) is the key drug for ALL. Studies on the relationship between High-Dose methotrexate (HD-MTX) toxicity and methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C genes have drawn different conclusions. This study aimed to investigate the relationship between the polymorphism of MTHFR C677T and A1298C genes and the toxicity responses of MTX. Methods: The MTHFR C677T and A1298C genotypes of 271 children with ALL who received HD-MTX chemotherapy in southern China from September 2017 to June 2021 were analyzed, and the toxicity of HD-MTX was evaluated and analyzed according to Common Terminology Criteria for Adverse Events (CTCAE) 5.0. Results: The MTHFR C677T and A1298C gene polymorphisms were not correlated with the 48-hour MTX blood concentrations (P>0.05). Unconditional logistic regression model analysis also revealed that the risk of liver function impairment [odds ratio (OR) =1.656, 95% confidence interval (CI): 1.179-2.324, P<0.05] and mucosal damage (OR =1.508, 95% CI: 1.042-2.183, P<0.05) were 1.656 and 1.508 times higher for the heterozygous mutant (CT), and homozygous mutant (TT) mutant type than for the wild-type (CC), wild-type, respectively. The risk of neutropenia and liver function impairment were 0.498 (OR =0.498, 95% CI: 0.251-0.989, P<0.05) and 6.067 (OR =6.067, 95% CI: 1.183-31.102, P<0.05) times higher in low-risk children with CT+TT mutant genotypes than in those with CC wild genotypes, respectively. Furthermore, the risk of mucosal damage was 1.906 times higher in high-risk children with the CT+TT genotype than in those with the CC genotype (OR =1.906, 95% CI: 1.033-3.518, P<0.05). The MTHFR A1298C genotypes differed in the incidence of liver function damage and gastrointestinal toxic reactions in children with ALL. Nonetheless, no increased risk of liver function impairment nor gastrointestinal reactions in children with the heterozygous mutant (AC)+CC mutation was observed. Conclusions: Advancements in MTHFR genotype testing in children with ALL and the introduction of personalised treatments based on genotype results during HD-MTX chemotherapy will help to predict, prevent, and reduce the occurrence of adverse MTX-related toxic reactions.

Clinical summary of pediatric acute lymphoblastic leukemia patients complicated with asparaginase-associated pancreatitis in SCCLG-ALL-2016 protocol.

Asparaginase-associated pancreatitis (AAP) is a common and fatal complication after ASNase treatment in acute lymphoblastic leukemia(ALL). Here, a total of 1063 pediatric ALL patients treated with SCCLG-ALL-2016 regimen were collected since October 2016 to June 2020, including 35 patients with AAP. The clinical characteristics of AAP and non-AAP patients were compared. In AAP patients, the possible factors that affected the recurrence of AAP were analyzed, and the possible risk factors related to ALL-relapse were discussed. The results showed that age was a risk factor (P = .017) that affect the occurrence of AAP. In AAP patients, AAP tended to develop after the second use of PEG-ASNase (25.71%). In the follow-up chemotherapy, 17 patients re-exposed to ASNase and 7 cases developed AAP again with a percentage was 41.2%. There were no special factors that related with the recurrence of AAP. This study also found no association between the occurrence of AAP and prognosis of ALL, with the 4-year incidence of ALL relapse in AAP and non-AAP patients were 15.9% v.s.11.7% (HR: 1.009, 95% CI:0.370-2.752, P = .986), and there were no special factors that related with the ALL relapse among AAP patients. Based on the above results, the occurrence of AAP is related to age and should be vigilant after the second use of PEG-ASNase after use in pediatric ALL patients. Moreover, AAP is not associated with ALL relapse, but there is a high AAP recurrence rate when re-exposure to ASNase.

Mutational landscape and clinical outcome of pediatric acute myeloid leukemia with 11q23/KMT2A rearrangements.

BACKGROUND: Alterations of 11q23/KMT2A are the most prevalent cytogenetic abnormalities in acute myeloid leukemia (AML) and the prognostic significance of 11q23/KMT2A-rearranged AML based on various translocation partners varies among different studies. However, few studies evaluated the molecular characteristics of 11q23/KMT2A-rearranged pediatric AML. We aim to analyze the mutational landscape of 11q23/KMT2A-rearranged AML and assess their prognostic value in outcomes. METHODS: The mutational landscape and clinical prognosis of 105 children with 11q23/KMT2A-rearranged AML in comparison with 277 children with non-11q23/KMT2A-rearranged AML were analyzed using publicly accessible next-generation sequencing data from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) dataset. RESULTS: Pediatric AML patients with 11q23/KMT2A-rearrangements harbored a low number of mutations (Median, 1 mutation/patient, range, 1-22), 58% of which involved in RAS pathway mutations (KRAS, NRAS, and PTPN11) and 10.5% of which comprised of SETD2 mutations. Compared with non-11q23/KMT2A-rearranged AML, the incidence of KRAS (32.4% vs. 10.1%, P〈0.001) and SETD2 (10.5% vs. 1.4%, P=0.001) gene mutations in 11q23/KMT2A-rearranged AML was significantly higher. Both KRAS and SETD2 mutations occurred more often in t(10;11)(p12;q23). KRAS mutations were correlated with worse 5-year event-free survival [EFS] (Plog-rank = 0.001) and 5-year overall survival [OS] (Plog-rank = 0.009) and the presence of SETD2 mutations increases the 5-year relapse rate (PGray = 0.004). Multivariate analyses confirmed KRAS mutations in 11q23/KMT2A-rearranged AML as an independent predictor for poor EFS (hazard ratio [HR] = 2.10, P=0.05) and OS (HR = 2.39, P=0.054). CONCLUSION: Our findings show that pediatric patients with 11q23/KMT2A rearrangements have characteristic mutation patterns and varying clinical outcomes depending on different translocation partners, which could be utilized to develop more accurate risk stratification and tailored therapies.

Prognostic value and outcome for acute lymphocytic leukemia in children with MLL rearrangement: a case-control study.

PURPOSE: To evaluate the prognostic factors and outcome for acute lymphoblastic leukemia (ALL) in children with MLL rearrangement (MLL-r). METHODS: A total of 124 pediatric patients who were diagnosed with ALL were classified into two groups based on the MLL-r status by using a retrospective case-control study method from June 2008 to June 2020. RESULTS: The prevalence of MLL-r positive in the whole cohort was 4.9%. The complete remission (CR) rate on Day 33 in the MLL-r positive group was not statistically different from the negative group (96.8% vs 97.8%, P = 0.736). Multivariate analysis showed that T-cell, white blood cell counts (WBC) ≥ 50 × 109/L, MLL-AF4, and D15 minimal residual disease (MRD) positive were independent risk factors affecting the prognosis of MLL-r positive children. Stem cell transplantation (SCT) was a favorable independent prognostic factor affecting event-free survival (EFS) in MLL-r positive patients (P = 0.027), and there was a trend toward an independent prognostic effect on overall survival (OS) (P = 0.065). The 10-year predicted EFS for patients with MLL-AF4, MLL-PTD, MLL-ENL, other MLL partner genes, and MLL-r negative cases were 46.67 ± 28.61%, 85.71 ± 22.37%, 75 ± 32.41%, 75 ± 32.41%, and 77.33 ± 10.81%, respectively (P = 0.048). The 10-year predicted OS were 46.67 ± 28.61%, 85.71 ± 22.37%, 75 ± 32.41%, 75 ± 32.41%, and 85.2 ± 9.77%, respectively (P = 0.049). The 124 patients with ALL were followed up and eventually 5 (4%) cases relapsed, with a median relapse time of 3.9 years. CONCLUSION: Patients with MLL-r positive ALL have moderate remission rates, but are prone to relapse with low overall survival. The outcome of MLL-r positive ALL was closely related to the partner genes, and clinical attention should be paid to screening for MLL partner genes and combining them with other prognostic factors for accurate risk stratification.

Analysis of clinical characteristics and prognostic factors associated with EBV-associated HLH in children.

Purpose Our aim is to analyze the clinical characteristics and prognostic factors of Epstein-Barr (EB) virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) in children. Methods Children with newly diagnosed HLH were retrospectively analyzed. Results Finally, a total of 95 children with HLH were enrolled in this study, including 43 (45.3%) with EBV-HLH and 52 (54.7%) with non-EBV-HLH. Laboratory tests showed that the levels of absolute neutrophil count (ANC) decrease (P = 0.031) and triglycerides (TG) increase (P = 0.036) in the EBV-HLH group were statistically significant compared with those in the non-EBV-HLH group, respectively. We found that the remission rate during induction period in the EBV-HLH group and non-EBV-HLH group was 75.8% and 89.3%, respectively. The correlation analysis showed that the elevated degree of total bilirubin (TBIL) (P = 0.042), triglyceride (TG) (P = 0.009), serum ferritin (SF) (P = 0.008) and interleukin-8 (IL-8) (P = 0.004) were related with the remission rate during induction in the EBV-HLH group. Further univariate analysis showed that the elevated degree of TBIL (P = 0.048) and TG (P = 0.019) were significant risk factors for the remission rate during induction in the EBV-HLH group. In the multivariate analysis, we observed that there was statistical significance for the degree of TG elevation (P = 0.015) between the two groups. The correlation analysis showed that the elevated degree of TBIL (P = 0.030), the elevated degree of SF (P = 0.020) and the elevated degree of interleukin-6 (P = 0.010) were related to the induction mortality of children with EBV-HLH. Conclusion TBIL and TG are valid indicators to assess the efficacy and prognosis of EVBHLH among children in induction period.

[Clinical Characteristic, Diagnosis and Treatment of Acute Lymphoblastic Leukemia Combined with Pneumocystis Carinii Pneumonia in Children].

OBJECTIVE: To investigate the clinical characteristics and treatment of pneumocystis carinii pneumonia (PCP) in children with acute lymphoblastic leukemia (ALL), in order to improve the early diagnosis and effective treatment. METHODS: Clinical data of five children with ALL developing PCP in the post-chemotherapy granulocyte deficiency phase were analyzed retrospectively. The clinical manifestations, laboratory tests, imaging findings, treatment methods and effect were summarized. RESULTS: The male-to-female ratio of the five children was 1∶4, and the median age was 5.5 (2.9-8) years old. All patients developed PCP during granulocyte deficiency phase after induction remission chemotherapy. The clinical manifestations were generally non-specific, including high fever, tachypnea, dyspnea, non-severe cough, and rare rales in two lungs (wet rales in two patients). Laboratory tests showed elevated C-reactive protein (CRP), serum procalcitonin (PCT), (1,3)-ß-D-glucan (BDG), lactate dehydrogenase (LDH) and inflammatory factors including IL-2R, IL-6 and IL-8. Chest CT showed diffuse bilateral infiltrates with patchy hyperdense shadows. Pneumocystis carinii(PC) was detected in bronchoalveolar lavage fluid (BALF) or induced sputum by high-throughput sequencing in all patients. When PCP was suspected, chemotherapy was discontinued immediately, treatment of trimethoprim-sulfame thoxazole (TMP-SMX) combined with caspofungin against PC was started, and adjunctive methylprednisolone was used. Meanwhile, granulocyte-stimulating factor and gammaglobulin were given as the supportive treatment. All patients were transferred to PICU receiving mechanical ventilation due to respiratory distress during treatment. Four children were cured and one died. CONCLUSION: PCP should be highly suspected in ALL children with high fever, dyspnea, increased LDH and BDG, and diffuse patchy hyperdense shadow or solid changes in lung CT. The pathogen detection of respiratory specimens should be improved as soon as possible. TMP/SMZ is the first-line drug against PCP, and the combination of Caspofungin and TMP/SMZ treatment for NH-PCP may have a better efficacy. Patients with moderate and severe NH-PCP may benefit from glucocorticoid.

Population Pharmacokinetics and Initial Dosage Optimization of Tacrolimus in Pediatric Hematopoietic Stem Cell Transplant Patients.

Background: There is a substantial lack of tacrolimus pharmacokinetic information in pediatric hematopoietic stem cell transplant (HSCT) patients. This study aimed to develop population pharmacokinetics (PopPK) of tacrolimus in pediatric HSCT patients and to devise model-guided dosage regimens. Methods: A retrospective analysis was performed on 86 pediatric HSCT patients who received tacrolimus intravenously or orally. A total of 578 tacrolimus trough concentrations (C0) were available for pharmacokinetic analysis using a non-linear mixed-effects modeling method. Demographic and clinical data were included and assessed as covariates via the stepwise method. Bayesian estimators were used to devise pediatric dosage regimens that targeted C0 of 5-15 ng mL-1. Results: A one-compartment model with first-order absorption adequately described the tacrolimus pharmacokinetics. Clearance (CL), volume of distribution (V), and typical bioavailability (F) in this study were estimated to be 2.42 L h-1 (10.84%), 79.6 L (16.51%), and 19% (13.01%), respectively. Body weight, hematocrit, post-transplantation days, and caspofungin and azoles concomitant therapy were considered significant covariates for tacrolimus CL. Hematocrit had a significant impact on the V of tacrolimus. In the subgroup cohort of children (n = 24) with CYP3A5 genotype, the clearance was 1.38-fold higher in CYP3A5 expressers than in non-expressers. Simulation indicated that the initial dosage optimation of tacrolimus for intravenous and oral administration was recommended as 0.025 and 0.1 mg kg-1 d-1 (q12h), respectively. Conclusion: A PopPK model for tacrolimus in pediatric HSCT patients was developed, showing good predictive performance. Model-devised dosage regimens with trough tacrolimus concentrations provide a practical strategy for achieving the therapeutic range.