Measurable residual disease monitoring by ddPCR in the early posttransplant period complements the traditional MFC method to predict relapse after HSCT in AML/MDS: a multicenter retrospective study.

BACKGROUND: Droplet digital PCR (ddPCR) is widely applied to monitor measurable residual disease (MRD). However, there are limited studies on the feasibility of ddPCR-MRD monitoring after allogeneic hematopoietic stem cell transplantation (allo-HSCT), especially targeting multiple molecular markers simultaneously. METHODS: Our study collected samples from patients with acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS) in complete remission after allo-HSCT between January 2018 and August 2021 to evaluate whether posttransplant ddPCR-MRD monitoring can identify patients at high risk of relapse. RESULTS: Of 152 patients, 58 (38.2%) were MRD positive by ddPCR within 4 months posttransplant, with a median variant allele frequency of 0.198%. The detectable DTA mutations (DNMT3A, TET2, and ASXL1 mutations) after allo-HSCT were not associated with an increased risk of relapse. After excluding DTA mutations, patients with ddPCR-MRD positivity had a significantly higher cumulative incidence of relapse (CIR, 38.7% vs. 9.7%, P < 0.001) and lower rates of relapse-free survival (RFS, 55.5% vs. 83.7%, P < 0.001) and overall survival (OS, 60.5% vs. 90.5%, P < 0.001). In multivariate analysis, ddPCR-MRD positivity of non-DTA genes was an independent adverse predictor for CIR (hazard ratio [HR], 4.02; P < 0.001), RFS (HR, 2.92; P = 0.002) and OS (HR, 3.12; P = 0.007). Moreover, the combination of ddPCR with multiparameter flow cytometry (MFC) can further accurately identify patients at high risk of relapse (F+/M+, HR, 22.44; P < 0.001, F+/M-, HR, 12.46; P < 0.001 and F-/M+, HR, 4.51; P = 0.003). CONCLUSION: ddPCR-MRD is a feasible approach to predict relapse after allo-HSCT in AML/MDS patients with non-DTA genes and is more accurate when combined with MFC. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT06000306. Registered 17 August 2023 -Retrospectively registered ( https://clinicaltrials.gov/study/NCT06000306?term=NCT06000306&rank=1 ).

A Case of Type 1 Triallelic Patterns at D5S818, D18S51, D6S1043, and FGA Demonstrated by Short Tandem Repeat Analysis.

The triallelic pattern of short tandem repeat (STR) is rare; especially, the case where this pattern exists at 4 loci has not been reported. Here, we report the type 1 triallelic patterns at D5S818, D18S51, D6S1043, and FGA from a Chinese family, which were observed during our routine chimerism assays. Before hematopoietic stem cell transplantation, the blood sample of the certain patient was analyzed by performing chimerism analysis. A preliminary STR analysis was also performed on the samples of the patient's parents. STR signal data illustrated that the sum of the peak chart areas of the two types inherited from the father was basically the same as that of the mother, belonging to the type 1 triallelic pattern. In addition, the patient's elder sister's STR result appeared to be normal. Altogether, we presented a pedigree, in which the triallelic pattern was linked by inheritance in the family. This is the first reported case of the triallelic pattern at D5S818, D18S51, D6S1043, and FGA all around the world. We hope that in the future there will be any tools to achieve accurate verification against this possibility.

Distribution of killer cell immunoglobulin-like receptor (KIR) genes in a large, multi-centre cohort of Chinese donors.

BACKGROUND: The killer cell immunoglobulin-like receptor (KIR), which mediates the killing function of NK cells, is an attractive candidate for adoptive cellular therapy. The ethnic distribution for China provides a unique opportunity to investigate KIR gene distribution. AIM: The aim of this study was to explore the relationship between population history and the rapidly evolving KIR genetic diversity. SUBJECTS AND METHODS: 8050 Chinese donors from 184 hospitals were included to analyse frequency, haplotype, and B-content data of 16 KIR genes, by PCR-SSP for KIR genotyping. RESULTS: KIR gene carrier frequencies were found similar to those observed in other studies on Han, but different from Thais, Japanese, Africans, and populations of West Eurasian ancestry. High-frequency KIR genotype profiles found in the present population were consistent with other studies on Han populations but different from those conducted on other cohorts. The majority of our cohort carried group A KIR gene motifs. Additionally, populations with similar geographic locations in China were shown clustered together, while Hainan and Xinjiang provinces were slightly separated from these. CONCLUSION: The distribution of KIR genes varies by geographic region, and different ethnic groups may be a confounding factor of KIR diversity.

Tri-allelic patterns at the D7S820 locus detected in two generations of a Chinese family.

Alleles at the D7S820 STR locus have 6-14 different numbers of a four-nucleotide (GATA) repeat motif arranged in tandem. The D7S820 tri-allelic pattern is rare and has not been reported in the Chinese population. In this study we report a three-banded pattern at the D7S820 locus observed in a Chinese family, in which four family members in two generations had tri-allelic D7S820 genotype 10-11-12 and one family member had an abnormal bi-allele genotype 10-11. All of the four tri-allelic cases had the genotype 10-11-12, probably due to three copies of the D7S820 STR sequence in all cells (Type 2 tri-allelic pattern), and deduced alleles 10-11 were a linked inheritance in this family.

A case of acute lung injury in a peripheral blood stem cell donor mobilized with pegylated recombinant human granulocyte colony-stimulating factor.

Pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) has been introduced for the mobilization of peripheral blood stem cells (PBSCs). However, no cases of acute lung injury (ALI) in healthy donors have been reported, and the underlying mechanisms remain poorly understood. We first reported a case of ALI caused by PEG-rhG-CSF in a healthy Chinese donor, characterized by hemoptysis, hypoxemia, and patchy shadows. Ultimately, hormone administration, planned PBSC collection, leukocyte debridement, and planned PBSC collection resulted in active control of the donor's ALI. The donor's symptoms improved without any adverse effects, and the PBSC collection proceeded without incident. Over time, the lung lesion was gradually absorbed and eventually returned to normal. PEG-rhG-CSF may contribute to ALI in healthy donors via mechanisms involving neutrophil aggregation, adhesion, and the release of inflammatory mediators in the lung. This case report examines the clinical manifestations, treatment, and mechanism of lung injury induced by PEG-rhG-CSF-mobilized PBSCs.

Donor aKIR genes influence the risk of EBV and CMV reactivation after anti-thymocyte globulin-based haploidentical hematopoietic stem cell transplantation.

Hematopoietic stem cell transplantation (HSCT) offers the highest curative potential for patients with hematological malignancies. Complications including infection, graft-versus-host disease (GVHD), and relapse reflect delayed or dysregulated immune reconstitution. After transplantation, NK cells rapidly reconstitute and are crucial for immune surveillance and immune tolerance. NK cell function is tightly regulated by killer immunoglobin-like receptors (KIRs). Previous studies have revealed that donor KIRs, especially some activated KIRs (aKIRs) are closely related to transplant outcomes. Here, we performed a retrospective study, including 323 patients who received haploidentical (haplo) HSCT in our center. In univariate analysis, donor KIR2DS1, KIR2DS3 and KIR3DS1 gene protected patients with lymphoid disease from Epstein-Barr virus (EBV) and cytomegalovirus (CMV) reactivation, while donor KIR2DS1, KIR2DS5 and KIR3DS1 gene conferred a higher risk of CMV reactivation for patients with myeloid disease. Multivariate analysis confirmed that donor telomeric (Tel) B/x and KIR2DS3 gene best protected patients with lymphoid disease from EBV (p = 0.017) and CMV reactivation (p = 0.004). In myeloid disease, grafts lacking Tel B/x and KIR2DS5 gene correlated with the lowest risk of CMV reactivation (p = 0.018). Besides, donor aKIR genes did not influence the rates of GVHD, relapse, non-relapse mortality (NRM) and overall survival (OS) in this study. The reactivation of EBV and CMV was associated with poor prognosis of haplo-HSCT. In conclusion, we found that donor aKIR genes might have a synergistic effect on CMV and EBV reactivation after haplo-HSCT. Whether the influence of donor aKIR genes varies with disease types remained to be studied.

Investigation of HLA susceptibility alleles and genotypes with hematological disease among Chinese Han population.

Several genes involved in the pathogenesis have been identified, with the human leukocyte antigen (HLA) system playing an essential role. However, the relationship between HLA and a cluster of hematological diseases has received little attention in China. Blood samples (n = 123913) from 43568 patients and 80345 individuals without known pathology were genotyped for HLA class I and II using sequencing-based typing. We discovered that HLA-A*11:01, B*40:01, C*01:02, DQB1*03:01, and DRB1*09:01 were prevalent in China. Furthermore, three high-frequency alleles (DQB1*03:01, DQB1*06:02, and DRB1*15:01) were found to be hazardous in malignant hematologic diseases when compared to controls. In addition, for benign hematologic disorders, 7 high-frequency risk alleles (A*01:01, B*46:01, C*01:02, DQB1*03:03, DQB1*05:02, DRB1*09:01, and DRB1*14:54) and 8 high-frequency susceptible genotypes (A*11:01-A*11:01, B*46:01-B*58:01, B*46:01-B*46:01, C*01:02-C*03:04, DQB1*03:01-DQB1*05:02, DQB1*03:03-DQB1*06:01, DRB1*09:01-DRB1*15:01, and DRB1*14:54-DRB1*15:01) were observed. To summarize, our findings indicate the association between HLA alleles/genotypes and a variety of hematological disorders, which is critical for disease surveillance.

Comprehensive analysis of immune-related lncRNAs in AML patients uncovers potential therapeutic targets and prognostic biomarkers.

Purpose: The objective of this study was to provide theoretically feasible strategies by understanding the relationship between the immune microenvironment and the diagnosis and prognosis of AML patients. To this end, we built a ceRNA network with lncRNAs as the core and analyzed the related lncRNAs in the immune microenvironment by bioinformatics analysis. Methods: AML transcriptome expression data and immune-related gene sets were obtained from TCGA and ImmPort. Utilizing Pearson correlation analysis, differentially expressed immune-related lncRNAs were identified. Then, the LASSO-Cox regression analysis was performed to generate a risk signature consisting immune-related lncRNAs. Accuracy of signature in predicting patient survival was evaluated using univariate and multivariate analysis. Next, GO and KEGG gene enrichment and ssGSEA were carried out for pathway enrichment analysis of 183 differentially expressed genes, followed by drug sensitivity and immune infiltration analysis with pRRophetic and CIBERSORT, respectively. Cytoscape was used to construct the ceRNA network for these lncRNAs. Results: 816 common lncRNAs were selected to acquire the components related to prognosis. The final risk signature established by multivariate Cox and stepwise regression analysis contained 12 lncRNAs engaged in tumor apoptotic and metastatic processes: LINC02595, HCP5, AC020934.2, AC008770.3, LINC01770, AC092718.4, AL589863.1, AC131097.4, AC012368.1, C1RL-AS1, STARD4-AS1, and AC243960.1. Based on this predictive model, high-risk patients exhibited lower overall survival rates than low-risk patients. Signature lncRNAs showed significant correlation with tumor-infiltrating immune cells. In addition, significant differences in PD-1/PD-L1 expression and bleomycin/paclitaxel sensitivity were observed between risk groups. Conclusion: LncRNAs related to immune microenvironment were prospective prognostic and therapeutic options for AML.

A metabolic atlas of blood cells in young and aged mice identifies uridine as a metabolite to rejuvenate aged hematopoietic stem cells.

Aging of hematopoietic stem cells (HSCs) is accompanied by impaired self-renewal ability, myeloid skewing, immunodeficiencies and increased susceptibility to malignancies. Although previous studies highlighted the pivotal roles of individual metabolites in hematopoiesis, comprehensive and high-resolution metabolomic profiles of different hematopoietic cells across ages are still lacking. In this study, we created a metabolome atlas of different blood cells across ages in mice. We reveal here that purine, pyrimidine and retinol metabolism are enriched in young hematopoietic stem and progenitor cells (HSPCs), whereas glutamate and sphingolipid metabolism are concentrated in aged HSPCs. Through metabolic screening, we identified uridine as a potential regulator to rejuvenate aged HSPCs. Mechanistically, uridine treatment upregulates the FoxO signaling pathway and enhances self-renewal while suppressing inflammation in aged HSCs. Finally, we constructed an open-source platform for public easy access and metabolomic analysis in blood cells. Collectively, we provide a resource for metabolic studies in hematopoiesis that can contribute to future anti-aging metabolite screening.

Case report: TP53 c.848G>A germline mutation as a possible screening target at initial diagnosis for acute lymphoblastic leukemia.

BACKGROUD: Li-Fraumeni syndrome is a hereditary tumor syndrome characterized by an elevated risk of malignancy, particularly acute lymphoblastic leukemia (ALL), which can be caused by the heterozygous germline mutation. TP53 gene germline mutation is considered a potential risk factor and crucial prognostic parameter for acute leukemia development and diagnosis, but rarely occurs in adults, and its specific pathogenic significance in acute leukemia is unclear. CASE PRESENTATION: We describes a case of a 45-year-old woman diagnosed with ALL. Whole-exome sequencing approach identified one of the TP53 germline mutations from her bone marrow sample with possible pathogenic significance, c.848G>A (p.Arg283His) heterozygous missense mutation located on exon 8, which was further verified in her hair, oral mucous and nail samples. Family pedigree screening revealed that the same TP53 genetic variant was present in the patient's father and non-donor son, whereas not in the donor. Digital PCR observed that this point mutation frequency dropped post-transplantation but remained low during maintenance therapy when the patient was leukemia-free. CONCLUSION: This suspected Li-Fraumeni syndrome case report with a likely pathogenic heterozygous TP53 variant expands the cancer genetic spectrum. Screening her family members for mutations facilitates identifying the optimal relative donor and avoids unnecessary treatment by monitoring TP53 germline mutations for minimal residual disease following hematopoietic stem cell transplantation. Its potential roles in hematological malignant tumor development and clinical pathogenic implications necessitate further probing.

The novel HLA-DQB1*06:475 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-DQB1*06:475 differs from HLA-DQB1*06:35 by one nucleotide in exon 2.

The novel HLA-A*30:01:24 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-A*30:01:24 differs from HLA-A*30:01:01:01 by one nucleotide in exon 3.

The novel HLA-C*04:490 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-C*04:490 differs from HLA-C*04:01:01:01 by one nucleotide in exon 3.

The novel HLA-A*02:1068Q allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-A*02:1068Q differs from HLA-A*02:03:01:01 by one nucleotide in exon 1.

The novel HLA-C*03:04:74 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-C*03:04:74 differs from HLA-C*03:04:01:01 by one nucleotide in exon 6.

The novel HLA-B*35:563 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-B*35:563 differs from HLA-B*35:03:01:01 by one nucleotide in exon 4.

The novel HLA-B*15:638 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-B*15:638 differs from HLA-B*15:01:01:01 by one nucleotide in exon 2.

The novel HLA-DQB1*03:03:29 allele, identified by sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-DQB1*03:03:29 differs from HLA-DQB1*03:03:02:01 by one nucleotide in exon 2.

The novel HLA-C*15:02:58 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-C*15:02:58 differs from HLA-C*15:02:01:01 by one nucleotide in exon 1.