Impact of "day 90" CD4+ T cells on clinical outcomes in children with relapsed/refractory acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: The severity of complications after hematopoietic stem cell transplantation (HSCT) is dictated by the degree of immune reconstitution. However, the connection between immune reconstitution and the prognosis of pediatric patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains unclear. Therefore, the aim of this study was to evaluate the impact of lymphocyte subsets in children diagnosed with refractory or relapsed acute myeloid leukemia (R/R-AML) after allo-HSCT. METHODS: We retrospectively investigated the prognosis and lymphocyte subsets at d 90 (D90) post-allo-HSCT in 130 children diagnosed with R/R-AML between September 2019 and October 2022 at the Children's Hospital of Soochow University. Lymphocyte subgroups were assessed by flow cytometric analysis on D90 and compared among human leukocyte antigen (HLA)-matched sibling donor HSCT (MSD) (n = 14), haploidentical donor HSCT (n = 94), and HLA-matched unrelated donor HSCT (n = 22) groups. The associations between the counts and frequencies of lymphocyte subgroups and prognosis were assessed. RESULTS: In the MSD group, CD4+ T cell frequency and count were the highest (P < 0.001). Among the examined lymphocyte subsets, a lower proportion of CD4+ T cells (<14.535 %) at D90 correlated with a higher risk of cytomegalovirus infection (P = 0.002). A higher CD4+ T cell count (>121.39/µL) at D90 after HSCT was the single predictor of a lower fatality risk across all lymphocyte subgroups (univariate: P = 0.038 cut-off: 121.39/µL; multivariate: P = 0.036). No association with relapse was observed. CONCLUSIONS: CD4+ T cell count may be used to identify pediatric patients with R/R-AML with a greater mortality risk early after HSCT.

Pediatric acute myeloid leukemia with t(8;21) and KIT mutation treatment with avapritinib post-stem cell transplantation: a report of four cases.

Acute myeloid leukemia (AML) with t(8;21) (q22;q22), which forms RUNX1::RUNX1T1 fusion gene, is classified as a favorable-risk group. However, the presence of mutations in KIT exon 17 results in an adverse prognosis in this group. Avapritinib, a novel tyrosine kinase inhibitor, was designed to target KIT mutation. We report a retrospective study of four pediatric patients with AML with t(8:21) and KIT exon 17 mutation who were treated with avapritinib, three of them failed to demethylate drugs and donor lymphocyte infusion targeting RUNX1::RUNX1T1-positivity after allogeneic hematopoietic stem cell transplantation (allo-HSCT). So far, all patients with RUNX1::RUNX1T1 positivity had turned negative after 1, 9, 7, 2 months of avapritinib treatment. The common adverse effect of avapritinib is neutropenia, which is well-tolerated. This case series indicates that avapritinib may be effective and safe for preemptive treatment of children with AML with t(8;21) and KIT mutation after allo-HSCT, providing a treatment option for preventing relapse after allo-HSCT.

Congenital dyserythropoietic anemia type II in a newborn with a novel compound heterozygous mutation in the SEC23B: a case report and review of the literature.

Congenital dyserythropoietic anemia type II (CDA II) refers to a group of extremely rare heterozygous disorders characterized by ineffective erythropoiesis and morphological abnormalities of erythrocytes and bone marrow erythroblasts. Six types of CDA with differing heterogenous genetic mutations have been identified to date. Due to the genetic and clinical heterogeneity of CDA, accurate diagnosis can be very challenging, especially with the clinical overlap observed between CDA and other dyserythropoietic diseases. A 1-month-old infant girl, born to a non-consanguineous family, presented with severe normocytic anemia that required transfusions every 2 to 3 weeks since birth, as well as jaundice. Whole exome sequencing revealed a novel compound heterozygosity in the SEC23B gene, thus establishing the diagnosis of CDA II. Analysis by multiple bioinformatics tools predicted that the mutant proteins were deleterious. Here, we report a novel variation in SEC23B that extends the mutation spectrum of SEC23B in the diagnosis of CDA II.

Decitabine combined with minimally myelosuppressive therapy for induction of remission in pediatric high-risk acute myeloid leukemia with chromosome 5q deletion: a report of three cases.

Cases of pediatric acute myeloid leukemia (AML) with complex karyotypes including chromosome 5 abnormalities are rare and have a very poor prognosis. Management of AML with monosomy 5/del(5q) has been inconsistent. We treated three adolescents with this AML subtype using combined low-dose cytarabine and mitoxantrone, concurrently with decitabine and G-CSF, for remission induction. Decitabine was also included in the conditioning regimen before hematopoietic cell transplantation (HCT). All three patients achieved complete remission after treatment with this combination therapy. The treatment was well tolerated, and the patients are alive and free of disease at 3.6, 3.2, and 3.0 years after HCT, respectively.

PD-1 Checkpoint Blockade in Patients for Acute Myeloid Leukemia after HSCT Relapse Resulted in Severe GVHD and sHLH.

Treatment with immune checkpoint inhibitors (ICI) such as carrizumab leads to immune-mediated adverse effects including severe acute graft versus host disease (aGVHD) and secondary hemophagocytic syndrome (sHLH). Herein, we present two cases where aGVHD and sHLH developed after ICI administration, which was treated using methylprednisolone (MP). They developed high-grade fever complicated with liver dysfunction and diarrhea 1 day after ICI administration. Treatment with MP does not alleviate symptoms because of steroid resistance. Hyperbilirubinemia, rash with blisters, and watery diarrhea showed severe aGVHD. Hyperferritinemia, hypertriglyceridemia, and cytopenias suggested the diagnosis of HLH and met the criteria for sHLH diagnosis. They were thus administered intravenous high-dose MP, methotrexate (MTX), basiliximab, ruxolitinib, etc, which resolved these symptoms.

Minimally myelosuppressive regimen for remission induction in pediatric AML: long-term results of an observational study.

Treatment refusal and death as a result of toxicity account for most treatment failures among children with acute myeloid leukemia (AML) in resource-constrained settings. We recently reported the results of treating children with AML with a combination of low-dose cytarabine and mitoxantrone or omacetaxine mepesuccinate with concurrent granulocyte colony-stimulating factor (G-CSF) (low-dose chemotherapy [LDC]) for remission induction followed by standard postremission strategies. We have now expanded the initial cohort and have provided long-term follow-up. Eighty-three patients with AML were treated with the LDC regimen. During the study period, another 100 children with AML received a standard-dose chemotherapy (SDC) regimen. Complete remission was attained in 88.8% and 86.4% of patients after induction in the LDC and SDC groups, respectively (P = .436). Twenty-two patients in the LDC group received SDC for the second induction course. Significantly more high-risk AML patients were treated with the SDC regimen (P = .035). There were no significant differences between the LDC and SDC groups in 5-year event-free survival (61.4% ± 8.7% vs 65.2% ± 7.4%, respectively; P = .462), overall survival (72.7% ± 6.9% vs 72.5% ± 6.2%, respectively; P = .933), and incidence of relapse (20.5% ± 4.5% vs 17.6% ± 3.9%, respectively; P = .484). Clearance of mutations based on the average variant allele frequency at complete remission in the LDC and SDC groups was 1.9% vs 0.6% (P < .001) after induction I and 0.17% vs 0.078% (P = .052) after induction II. In conclusion, our study corroborated the high remission rate reported for children with AML who received at least 1 course of LDC. The results, although preliminary, also suggest that long-term survival of these children is comparable to that of children who receive SDC regimens.

Association of asparaginase-associated pancreatitis and ULK2 gene polymorphism.

The purpose of the study was to analyze the clinical characteristics and the course of diagnosis and therapy of asparaginase-associated pancreatitis (AAP) in childhood, improve the ability of diagnosis and treatment, and evaluate ULK2 gene polymorphism as a predictive factor for AAP. Data of 12 patients with childhood AAP were reviewed. Sanger sequencing of ULK2 gene was performed in AAP group (n=12) and control group (n=146). The main symptoms of AAP were abdominal pain and vomiting. Generally, the levels of amylase and lipase in the serum peaked within 72 h. Abdominal ultrasonography was performed in 11 patients; seven patients exhibited findings of pancreatic enlargement. Computed tomography was performed in 9 patients. Five patients exhibited findings of pancreatic enlargement and peri-pancreatic exudation. All patients were managed by fasting at the early stage, and seven patients underwent placement of a nasojejunal tube to receive enteral nutrition. One patient underwent endoscopic retrograde cholangiopancreatography (revealing dilation of the pancreatic duct) and endoscopic retrograde pancreatic drainage. Another patient developed signs of shock and received continuous renal replacement. There were no deaths caused by AAP. Therefore, early identification of patients at risk of AAP is of great importance. In addition, repeated elevation in the levels of pancreatic enzymes is indicative of complications. Sanger sequencing analysis of ULK2 gene showed that there was a significant difference of EXON1: -493C>T and EXON1: -308C>G between the AAP group and control group (P<0.0001). Thus, ULK2 gene polymorphism may be associated with the development of AAP. However, more validation of this finding is needed.