Unrelated umbilical cord blood transplantation with low-dose anti-thymocyte globulin for children with severe aplastic anemia: A case series.

OBJECTIVE: This study aimed to investigate the prognosis of unrelated umbilical cord blood transplantation (UCBT) using low-dose anti-thymocyte globulin (ATG) in children diagnosed with severe aplastic anemia (SAA). METHODS: This retrospective case series study was conducted involving pediatric SAA patients treated at the Capital Institute of Pediatrics from January 2020 to February 2023. All patients underwent a reduced-intensity conditioning (RIC) regimen alongside low-dose ATG. RESULTS: The study comprised nine patients (five males) with a median age of 5 years (range: 1.7 to 7 years). The median follow-up duration was 799 days (range: 367 to 1481 days), during which all patients survived. The median time interval from diagnosis to transplantation was 3 months (range: 1 to 9 months). The median dosage of ATG administered was 5 mg/kg (range: 2.5 to 7.5 mg/kg). The median durations for granulocyte and platelet engraftment were 15 days (range: 12 to 23 days) and 26 days (range: 12 to 41 days), respectively. Three patients experienced grade 2-4 acute graft-versus-host disease (aGVHD). Epstein-Barr virus (EBV) reactivation was observed in three patients, while cytomegalovirus (CMV) reactivation occurred in seven patients, with no cases of CMV disease or post-transplant lymphoproliferative disorder (PTLD). One patient experienced recurrence 15 months after transplantation due to influenza A infection. CONCLUSION: These findings indicate that SAA patients may attain a favorable prognosis following UCBT with a RIC regimen combined with low-dose ATG.

Clinical features and outcomes of infantile soft-tissue sarcoma: A multicenter retrospective study in Beijing.

Background: Soft-tissue sarcomas during infancy are rare and understudied. With no data on this specific condition, we performed a retrospective study of infant-onset sarcomas based on a multi-institutional cohort in Beijing, China, collected over the past decade. We reviewed infantile soft-tissue sarcomas' clinical characteristics, treatments, and outcomes. Materials and Methods: The patients with soft-tissue sarcoma diagnosed from 0 to 12 months in four primary children's hospitals in Beijing from January 2010 to December 2019 were evaluated. Results: Fifty-one patients were enrolled, including 31 males and 20 females. The median age at the diagnosis was five months (range, 0-12), and seven (13.7%) patients were diagnosed in the first month of their life. Histologically, twenty-five patients were diagnosed with rhabdomyosarcoma (RMS), six were diagnosed with extraosseous Ewing sarcoma (EES), and twenty were diagnosed with nonrhabdomyosarcoma soft-tissue sarcoma (NRSTS). The treatment principles and details of RMS focused on reference to the Intergroup Rhabdomyosarcoma Study Group (IRSG) protocols. For EES and NRSTS, chemotherapy was prescribed according to children's oncology group protocols. The five-year EFS/OS rates of RMS were 26.4% ± 19.5%/56.2 ± 17.8%, the five-year EFS/OS rate of EES was 50% ± 20.4%, and the five-year EFS/OS of NRSTS was 85.2% ± 9.8%/100%. Conclusions: Infant-onset soft-tissue sarcoma is heterogeneous. The primary location of the abdominal or pelvic cavity of RMS and EWS was at a later stage and had a poorer prognosis. Multimodal therapy resulted in successful disease control for the majority of patients. Standardization of treatment protocols will facilitate care for such challenging conditions.

Clinical features and prognosis of pediatric acute lymphocytic leukemia with JAK-STAT pathway genetic abnormalities: a case series.

The objective of this study is to explore the clinical features and outcomes of pediatric patients with acute lymphoblastic leukemia (ALL) harboring JAK-STAT signaling pathway genetic abnormalities. This retrospective case series examined the clinical data of pediatric patients diagnosed with ALL harboring JAK-STAT pathway genetic abnormality at the Children's Hospital of the Capital Institute of Pediatrics between January 2016 and January 2022. Bone marrow next-generation sequencing was used to reveal the JAK pathway abnormalities. Descriptive statistics were used. From 432 children with ALL during the study period, eight had JAK-STAT pathway genetic abnormalities. Regarding immunotyping, there were four patients with common-B cell types and one with pre-B cell type. The three patients with T-ALL had early T-cell precursor(ETP) type, pre-T cell type, and T cell type. Gene mutations were more common than fusion genes. There was no central nervous system involvement in eight patients. All patients were considered at least at intermediate risk before treatments. Four patients underwent hematopoietic stem cell transplantation (HSCT). One child had a comprehensive relapse and died. The child had a severe infection and could not tolerate high-intensity chemotherapy. Another child relapsed 2 years after HSCT and died. Disease-free survival was achieved in six children. JAK-STAT pathway genetic abnormalities in pediatric Ph-like ALL are rare. Special attention should be paid to treatment-related complications, such as infection and combination therapy (chemotherapy, small molecule targeted drugs, immunotherapy, etc.) to reduce treatment-related death and improve long-term quality of life.

[Clinical Efficacy of Haplo-HSCT of ATG Combined with PTCy for Children with Myelodysplastic Syndrome].

OBJECTIVE: To investigate the efficacy and safety of haploidentical hematopoietic stem cell transplantation (haplo-HSCT) in combination of ATG and post-transplant cyclophosphamide (PTCy) -induced immune tolerance after transplantation in treatment of childhood myelodysplastic syndromes(MDS）. METHODS: From July 2016 to November 2020, a total of 8 children with MDS receiving the haploidentical allo-HSCT combined with ATG and PTCy-induced immune tolerance after transplantation in our hospital were enrolled, whose clinical data were retrospected and analyzed. RESULTS: Median age at diagnosis of the 8 children (1 male and 7 females) was 6.4 (range, 10 months to 15 years) years old. The median medical history of MDS was 2.7 years (range, 3 months to 8 years). Among the 8 patients, 7 cases were diagnosed with refractory cytopenia of childhood and one with refractory anemia with excess of blasts. The HSC donors were father, mother or brother of patients and HLA matching in 6-9/12 loci were identical. All the donors were healthy and didn't carry the same pathogenic genes as the recipients. The median age of donors was 36.4 (range, 25 to 49) years old. The median mononuclear cell (MNC) number of the graft was 19.8, ranging in (13.2-47.3)×108/kg, and the median CD34+ cell number was 11.8×106/kg, ranging in (5.0-18.3)×106/kg. Graft-versus-host disease prophylactic regimen was started on day 3 and 4 after transplantation, in which cyclophosphamide (50 mg/kg·d) was administered by intravenous infusion. From day 5 after transplantation, low-dose tacrolimus was administered by intravenous infusion and mycophenolate mofetil was administered orally. The median time of neutrophil and platelet engraftment was 12.6 (rang, 11 to 15) days and 13.3 (rang, 11 to 18) days, respectively. All the patients achieved full donor chimerism on neutrophil engraftment after transplantation. The median follow-up time was 1 032 (rang, 747 to 1 536) days. Both overall survival rate and disease-free survival rate were 100%. CONCLUSION: Haplo-HSCT combined with ATG and PTCy-induced immune tolerance after transplantation is a safe and effective treatment for children with MDS.

Analysis of Multiple Vitamins Serum Levels and Disease-Related Factors in Children with Acute Leukemia.

Objective: To explore the relationship between vitamins levels and disease-related indicators in children with acute leukemia (AL). Methods: A total of 107 hospitalized children with AL were enrolled in this study and assigned to one group in each of the following categories: infected group (n = 52) and noninfected group (n = 55); treatment remission group (n = 56) and nonremission group (n = 51); high-risk (HR) group (n = 44), intermediate risk (IR) group (n = 53), and slight risk (SR) group (n = 8); cyclophosphamide + cytosine arabinoside+6-mercaptopurine + pegaspargase group (CAML, n = 15); methotrexate group (MTX, n = 9); and vindesine + daunomycin + L-asparaginasum + prednisone (VALP, n = 38). Hematological and serological parameters, hepatic and renal function, and changes in vitamins A, B1, B2, B6, B9, B12, C, D, and E serum content in children with AL were analyzed to investigate their relationship with AL disease-related factors. Results: The vitamin D level was significantly higher in the noninfected group than in the infected group (P < 0.05). Compared with the nonremission group, the level of vitamin B1 in the treatment remission group was significantly higher, while the levels of vitamin B6 and B12 were notably lower (P < 0.05). The levels of vitamins B6 and B12 were notably different among the treatment groups. Multivariate analysis showed that hemoglobin (Hb) and C-reactive protein (CRP) were predisposing factors of AL in children. The disease type (acute lymphoblastic leukemia/acute myelogenous leukemia) was the factor affecting remission in AL children. Abnormal kidney function and the occurrence of icterus were the influencing factors for the risk degree in AL children. Platelet (PLT) count, activated partial thromboplastin time (APTT), neutrophils (N), and immunophenotype were shown to affect the choice of therapeutic regimens. Conclusion: There are notable vitamins imbalances in children with AL. The imbalances influence disease-related factors and therefore provide some references for the prognosis and treatment of AL.

Clinical outcomes of individualized busulfan-dosing in hematopoietic stem cell transplantation in Chinese children undergoing with therapeutic drug monitoring.

To identify relationships between busulfan (Bu) exposure and outcomes of a cohort pediatric patients receiving hematopoietic stem cell transplantation (HSCT), along with a targeted busulfan-based conditioning regimen. We retrospectively evaluated targeted busulfan concentrations in 53 pediatric patients (age 0.4-16 years) who received busulfan 4 times daily according to recommended weight-based doses in a single-center analysis between 2018 and 2020. In this trial, individual busulfan pharmacokinetics were performed following dose 5 of the conditioning regimen. Twenty four of 53 patients (45.3%) studies did not require dose adjustments. Equal number of patients (24/53) required one dose adjustments while two-dose adjustment applied for 5 of 53 (9.4%). Twenty-one percent of the patients exhibited ll-lV aGVHD. The incidence of veno-occlusive disease (VOD) was in 3.8% of the 53 patients, while incidence of hemorrhagic cystitis (II-III) reached to 9.7%. Engraftment was successful in 98% of the 53 patients with relapse in 2% of cases. The probability of overall survival and disease-free survival at day 100 was 96% and 94%, respectively. In conclusion, therapeutic drug monitoring (TDM) and individualization of Bu dosage are essential to improve the efficacy and safety of busulfan-based regimen in Chinese pediatric HSCT recipients.

Frequency detection of BRAF V600E mutation in a cohort of pediatric langerhans cell histiocytosis patients by next-generation sequencing.

BACKGROUND: Langerhans cell histiocytosis (LCH) is a rare neoplastic disease that occurs in both children and adults, and BRAF V600E is detected in up to 64% of the patients. Several studies have discussed the associations between BRAF V600E mutation and clinicopathological manifestations, but no clear conclusions have been drawn regarding the clinical significance of the mutation in pediatric patients. RESULTS: We retrieved the clinical information for 148 pediatric LCH patients and investigated the BRAF V600E mutation using next-generation sequencing alone or with droplet digital PCR. The overall positive rate of BRAF V600E was 60/148 (41%). The type of sample (peripheral blood and formalin-fixed paraffin-embedded tissue) used for testing was significantly associated with the BRAF V600E mutation status (p-value = 0.000 and 0.000). The risk of recurrence declined in patients who received targeted therapy (p-value = 0.006; hazard ratio 0.164, 95%CI: 0.046 to 0.583). However, no correlation was found between the BRAF V600E status and gender, age, stage, specific organ affected, TP53 mutation status, masses close to the lesion or recurrence. CONCLUSIONS: This is the largest pediatric LCH study conducted with a Chinese population to date. BRAF V600E in LCH may occur less in East Asian populations than in other ethnic groups, regardless of age. Biopsy tissue is a more sensitive sample for BRAF mutation screening because not all of circulating DNA is tumoral. Approaches with low limit of detection or high sensitivity are recommended for mutation screening to avoid type I and II errors.

[Cladribine for 13 cases refractory high-risk children Langerhans cell histiocytosis].

OBJECTIVE: To observe the efficacy and adverse reaction of the improvement program of cladribine combined with cytarabine (2-CdA+Ara-C) in treatment of children with refractory high-risk Langerhans cell histiocytosis (LCH). METHODS: 13 patients with refractory high-risk LCH or recurrent LCH were treated by combined 2-CdA+Ara-C chemotherapy. The treatment efficacy and the disease state in the process were evaluated according to the Histiocyte Society Evaluation and Treatment Guidelines (2009). The drug toxicity was evaluated according to the Common Terminology Criteria Adverse Events Version 4.0 (CTCAE v4.0, 2009). RESULTS: Of 13 patients, 10 cases achieved non active disease (NAD); 2 patients with liver cirrhosis before the improvement program with CIP-LCH-2012 gave up the treatment after 1 course of therapy; 1 patient died of infectious shock after chemotherapy with severe pulmonary infection and intestinal infection. All 13 patients had grade 3 of blood and lymphatic system toxicity; 10 patients had grade 1 of hepatobiliary and gastrointestinal side effects; 3 patients with liver cirrhosis before the improvement program had grade 2 or grade 3 of hepatobiliary system and gastrointestinal system side effects, including 1 patient of death. CONCLUSION: The improvement program of CIP-LCH-2012 had significant efficacy for children with refractory high-risk and relapsed LCH. The cladribine-associated toxicity was of significant myelosuppression, which may be tolerated in the most children patients. The program could be considered as a recommended salvage therapy for multi-system LCH (MS-LCH) after failure of first-line therapy, and as a first-line therapy for MS-LCH with risk organ injury. The program should be used with caution or dose-adjustment consideration for pre-treatment of severe organ damage exist, especially cirrhosis.