Targeted gene sequencing and transcriptome sequencing reveal characteristics of NUP98 rearrangement in pediatric acute myeloid leukemia.

BACKGROUND: NUP98 rearrangements (NUP98-r) are rare but overrepresented mutations in pediatric acute myeloid leukemia (AML) patients. NUP98-r is often associated with chemotherapy resistance and a particularly poor prognosis. Therefore, characterizing pediatric AML with NUP98-r to identify aberrations is critically important. METHODS: Here, we retrospectively analyzed the clinicopathological features, genomic and transcriptomic landscapes, treatments, and outcomes of pediatric patients with AML. RESULTS: Nine patients with NUP98-r mutations were identified in our cohort of 142 patients. Ten mutated genes were detected in patients with NUP98-r. The frequency of FLT3-ITD mutations differed significantly between the groups harboring NUP98-r and those without NUP98-r (P = 0.035). Unsupervised hierarchical clustering via RNA sequencing data from 21 AML patients revealed that NUP98-r samples clustered together, strongly suggesting a distinct subtype. Compared with that in the non-NUP98-r fusion and no fusion groups, CMAHP expression was significantly upregulated in the NUP98-r samples (P < 0.001 and P = 0.001, respectively). Multivariate Cox regression analyses demonstrated that patients harboring NUP98-r (P < 0.001) and WT1 mutations (P = 0.030) had worse relapse-free survival, and patients harboring NUP98-r (P < 0.008) presented lower overall survival. CONCLUSIONS: These investigations contribute to the understanding of the molecular characteristics, risk stratification, and prognostic evaluation of pediatric AML patients.

Diagnostic Guidelines for Familial Hemophagocytic Lymphohistiocytosis Revisited.

Current HLH-2004-based diagnostic criteria for familial hemophagocytic lymphohistiocytosis (FHL) are based on expert opinion. Here we performed a case-control study to test and possibly improve these clinical criteria. We also developed two complementary expert opinion-based diagnostic strategies for FHL in patients with signs/symptoms suggestive of HLH, based on genetic and cellular cytotoxicity assays. The cases (n=366) were children <16 years with verified familial and/or genetic FHL (n=341) or Griscelli syndrome type 2 (GS2) (n=25); 276 from the HLH-94/HLH-2004 databases and 90 from the Italian HLH Registry. All fulfilled the HLH-94/HLH-2004 patient inclusion criteria. Controls were 374 children with systemic-onset juvenile idiopathic arthritis (sJIA) and 329+361 children in two cohorts with febrile infections that could be confused with HLH and sepsis, respectively. To provide complete data sets, multiple imputations were performed. The optimal model, based on the number of diagnostic criteria fulfilled from 17 variables studied, reveled almost similar diagnostic thresholds as the existing criteria, with accuracy 99.1% (sensitivity 97.1%; specificity 99.5%). Notably, assessment of the original HLH-2004 criteria revealed accuracy 97.4% (sensitivity 99.0%; specificity 97.1%). Since cellular cytotoxicity assays here constitute a separate diagnostic strategy, HLH-2004 criteria without NK-cell function was also studied which showed accuracy 99.0% (sensitivity 96.2%; specificity 99.5%). Thus, we conclude that the HLH-2004 criteria (without NK-cell function) have significant validity in their current form when tested against severe infections or sJIA. It is important to exclude underlying malignancies and atypical infections. In addition, complementary cellular and genetic diagnostic guidelines can facilitate necessary confirmation of clinical diagnosis.

The impact of neutrophil count on the results of metagenomic next-generation sequencing in immunocompromised febrile children.

Metagenomic next-generation sequencing (mNGS) has revolutionized the detection of pathogens, particularly in immunocompromised individuals such as pediatric patients undergoing intensive chemotherapy and hematopoietic stem cell transplantation. This study aims to explore the impact of neutrophil count on the diagnostic efficacy of mNGS in diagnosing infections in pediatric patients with febrile diseases. We conducted a retrospective analysis of pediatric patients with febrile diseases in the hematology/oncology department from January 2019 to September 2022. The study included 387 patients with 516 febrile episodes. Analyzing data from 516 pediatric cases, our study found that 70.7 % had febrile neutropenia (FN) and 29.3 % had febrile without neutropenia (FWN). mNGS demonstrated a high positive detection rate of 84.9 %, compared to 29.7 % for conventional microbiological tests (CMT). While the positive detection rates of mNGS were similar in both FN and FWN groups, bacterial pathogens were more frequently detected in FN patients. Furthermore, the rate of identifying a "probable" microbial etiology was lower in the FN group (46.8 %) compared to the FWN group (65.6 %, p＜0.001). When analyzing the types of organisms and specimens, the "probable" identification rates were particularly lower for viruses and fungi detected by mNGS, as well as in blood and nasopharyngeal swab samples. These findings underscore the significant influence of neutrophil counts on mNGS results in pediatric febrile patients and highlight the necessity for tailored diagnostic approaches in this population.

Human umbilical cord mesenchymal stem cell-based gene therapy for hemophilia B using scAAV-DJ/8-LP1-hFIXco transduction.

BACKGROUND: Hemophilia B is an X-linked bleeding disorder caused by a mutation in the gene responsible for encoding coagulation factor IX (FIX). Gene therapy offers promising potential for curing this disease. However, the current method of relatively high dosage of virus injection carries inherent risks. The purpose of this study was to introduce a novel scAAV-DJ/8-LP1-hFIXco vector transduced human umbilical cord blood derived mesenchymal stem cells (HUCMSCs) as an alternative cell-based gene therapy to conventional gene therapy for Hemophilia B. METHODS: The LP1-hFIXco gene structure was designed by us through searching the literature from NCBI and the scAAV-DJ/8-LP1-hFIXco vector was constructed by a commercial company. The HUCMSCs were cultivated in routine approach and transduced with scAAV-DJ/8-LP1-hFIXco vector. The human FIX activation system was employed for detection of hFIXco activity. The RNA and protein expression levels of the hFIXco were evaluated using PCR and western blot techniques. In animal studies, both NSG and F9-KO mice were used for the experiment, in which clotting time was utilized as a parameter for bleeding assessment. The immunohistochemical analysis was used to assess the distribution of HUCMSCs in mouse tissue sections. The safety for tumorigenicity of this cell-based gene therapy was evaluated by pathological observation after hematoxylin-eosin staining. RESULTS: The transduction of HUCMSCs with the scAAV-DJ/8-LP1-hFIXco vector results in consistent and sustainable secretion of human FIXco during 5 months period both in vitro and in mouse model. The secretion level (hFIXco activity: 97.1 ± 2.3% at day 7 to 48.8 ± 4.5% at 5 months) was comparable to that observed following intravenous injection with a high dose of the viral vector (hFIXco activity: 95.2 ± 2.2% to 40.8 ± 4.3%). After a 5-month observation period, no clonal expansions of the transduced cells in tissues were observed in any of the mice studied. CONCLUSIONS: We have discovered a novel and safer HUCMSCs mediated approach potentially effective for gene therapy in hemophilia B.

Comparison of plasma and blood cell samples in metagenomic next-generation sequencing for identification of the causative pathogens of fever.

Background: Metagenomic next-generation sequencing (mNGS) of plasma DNA has become an attractive diagnostic method for infectious diseases; however, the rate of false-positive results is high. This study aims to evaluate the diagnostic accuracy of mNGS in plasma versus blood cell samples for immunocompromised children with febrile diseases. Methods: The results of conventional microbiological test (CMT) and mNGS using plasma and blood cells in 106 patients with 128 episodes of febrile diseases from the Department of Hematology/Oncology were analyzed and described. Results: The positivity rates for CMT and mNGS of plasma and blood cells were 35.9 %, 84.4 % and 46.9 %, respectively (P < 0.001). Notably, mNGS identified multiple pathogens in a single specimen in 68.5 % of plasma samples and 38.3 % of blood cell samples (P < 0.001). Furthermore, plasma and blood cell mNGS identified causative pathogens in 58 and 46 cases, accounting for 53.7 % and 76.7 % of the mNGS-positive cases for each sample type, respectively (P = 0.002). By integrating results from both plasma and blood cell samples, causative pathogens were identified in 77 cases (60.2 %), enhancing sensitivity to 87.5 % but reducing specificity to 15.0 %, compared to plasma (65.9 % sensitivity and 20.0 % specificity) and blood cell samples (52.3 % sensitivity and 80.0 % specificity). Conclusions: mNGS of plasma is sensitive but has a high false-positive rate, while mNGS of blood cells has low sensitivity but higher specificity.

[Study on Down-regulation of Interleukin-1ß Secretion by Inhibiting ABCC1/MRP1 Transporter].

OBJECTIVE: To screen interleukin (IL)-1ß secretion-related membrane transporters by macrophage experiment in vitro and conventional knockout mice. METHODS: THP-1 cell line was differentiated to obtain human THP-1-derived macrophages, and the primary macrophages were obtained from human peripheral blood. FVB wild-type mice with the same sex and age were used as the controls of MRP1 knockout mice. The macrophages in abdominal cavity and bone marrow of mice were cultivated. The cells were treated with ABCC1/MRP1, ABCG2/BCRP, ABCB1/P-gp, OATP1B1, and MATE transporter inhibitors, then stimulated by lipopolysaccharide and adenosine triphosphate. The secretion level of IL-1ß was detected by ELISA, Western blot, and immunofluorescence. RESULTS: After inhibiting ABCC1/MRP1 transporter, the secretion of IL-1ß decreased significantly, while inhibition of the other 4 transporters had no effect. In animal experiment, the level of IL-1ß secreted by macrophages in bone marrow of MRP1 knockout mice was significantly lower than control group (P < 0.05). CONCLUSION: ABCC1/MRP1 transporter is a newly discovered IL-1ß secretion pathway, which is expected to become a new target for solving clinical problems such as cytokine release syndrome.

Combined Use of Emapalumab With Ruxolitinib and Dexamethasone as an Effective Treatment for Epstein-Barr Virus-associated Hemophagocytic Lymphohistiocytosis Complicated With Multiorgan Damage and Severe Infection.

Anti-interferon-γ monoclonal antibody emapalumab and JAK1/2 inhibitors ruxolitinib have been widely reported for the treatment of hemophagocytic lymphohistiocytosis (HLH) recently. These targeted drugs have fewer side effects and may provide new options for patients with HLH who are refractory to previous treatment or intolerant to chemotherapy. Herein, we reported a case of Epstein-Barr virus-related HLH, which did not respond well to HLH-94 plus ruxolitinib and developed severe fungal infection. The disease was successfully controlled after a combination therapy of emapalumab, ruxolitinib, and dexamethasone.

Unraveling resistance mechanisms in anti-CD19 chimeric antigen receptor-T therapy for B-ALL: a novel in vitro model and insights into target antigen dynamics.

BACKGROUND: Cellular immunotherapy, represented by the chimeric antigen receptor T cell (CAR-T), has exhibited high response rates, durable remission, and safety in vitro and in clinical trials. Unfortunately, anti-CD19 CAR-T (CART-19) treatment alone is prone to relapse and has a particularly poor prognosis in relapsed/refractory (r/r) B-ALL patients. To date, addressing or reducing relapse remains one of the research priorities to achieve broad clinical application. METHODS: We manufactured second generation CART-19 cells and validated their efficacy and safety in vitro and in vivo. Through co-culture of Nalm-6 cells with short-term cultured CART-19 cells, CD19-negative Nalm-6 cells were detected by flow cytometry, and further investigation of the relapsed cells and their resistance mechanisms was evaluated in vitro. RESULTS: In this study, we demonstrated that CART-19 cells had enhanced and specific antileukemic activities, and the survival of B-ALL mouse models after CART-19 treatment was significantly prolonged. We then shortened the culture time and applied the serum-free culture to expand CAR-T cells, followed by co-culturing CART-19 cells with Nalm-6 cells. Surprisingly, we observed the proliferation of CD19-negative Nalm-6 cells around 28 days. Identification of potential resistance mechanisms showed that the relapsed cells express truncated CD19 proteins with decreased levels and, more importantly, CAR expression was detected on the relapsed cell surface, which may ultimately keep them antigen-negative. Furthermore, it was validated that CART-22 and tandem CART-22/19 cells could effectively kill the relapsed cells, but neither could completely eradicate them. CONCLUSIONS: We successfully generated CART-19 cells and obtained a CD19-negative refractory relapsed B-ALL cell line, providing new insights into the underlying mechanisms of resistance and a new in vitro model for the treatment of r/r B-ALL patients with low antigen density.

The predictive utility of cytokines, procalcitonin and C-reactive protein among febrile pediatric hematology and oncology patients with severe sepsis or septic shock.

Severe sepsis and septic shock are life-threatening for pediatric hematology and oncology patient receiving chemotherapy. Th1/Th2 cytokines, C-reactive protein (CRP), and procalcitonin (PCT) are all thought to be associated with disease severity. The aim of this study was to prospectively verify the utility of Th1/Th2 cytokines and compare them with PCT and CRP in the prediction of adverse outcomes. Data on patients were collected from January 1, 2011, to December 31, 2020. Blood samples were taken for Th1/Th2 cytokine, CRP, and PCT measurements at the initial onset of infection. Severe infection (SI) was defined as severe sepsis or septic shock. Th1/Th2 cytokine levels were determined by using flow cytometric bead array technology. In total, 7,735 febrile episodes were included in this study. For SI prediction, the AUCs of IL-6, IL-10 and TNF-α were 0.814, 0.805 and 0.624, respectively, while IL-6 and IL-10 had high sensitivity and specificity. IL-6 > 220.85 pg/ml and IL-10 > 29.95 pg/ml had high odds ratio (OR) values of approximately 3.5 in the logistic regression. Within the subgroup analysis, for bloodstream infection (BSI) prediction, the AUCs of IL-10 and TNF-α were 0.757 and 0.694, respectively. For multiorgan dysfunction syndrome (MODS) prediction, the AUC of CRP was 0.606. The AUC of PCT for mortality prediction was 0.620. In conclusion, IL-6 and IL-10 provide good predictive value for the diagnosis of SI. For children with SI, IL-10 and TNF-α are associated with BSI, while CRP and PCT are associated with MODS and death, respectively.

The effect of the plasma methotrexate concentration during high-dose methotrexate therapy in childhood acute lymphoblastic leukemia.

Two hundred and thirty-one acute lymphoblastic leukemia (ALL) children with 1376 high-dose methotrexate (HD-MTX) courses (3-5 g/m2) were enrolled to analyze the influence of the plasma MTX concentration (CMTX) in ALL. The 24-h target peak CMTX (C24h) was set at 33 µmol/l for low-risk (LR) and 65 µmol/l for intermediate/high-risk (IR/HR) groups. The median C24h was 42.0 µmol/l and 69.7 µmol/l for LR and IR/HR groups, respectively. MTX excretion delay was observed in 14.6% of courses, which was more frequent in IR/HR groups (56.9% vs. LR group 40.2%, p = .014) and T-ALL patients (82.6% vs. B-ALL 47.1%, p = .001). MTX-related toxicities were more common in courses with MTX excretion delay. However, survival between the patients who failed to reach the target C24h or not, with or without MTX excretion delay, was comparable. These findings suggest that, owing to the effectiveness of risk stratification chemotherapy, CMTX does not exert an independent influence on the prognosis of childhood ALL.

Prognostic performance of IL-6 and IL-10 in febrile pediatric hematology/oncology patients with normal procalcitonin.

INTRODUCTION: It is important to predict adverse outcomes in febrile children with hematology/oncology diseases. Procalcitonin (PCT) is a promising biomarker for the prediction of infection severity, but further studies have revealed its performance in excluding adverse outcomes of infection. IL-6 and IL-10 were reported to have a close association with those infection outcomes. The aim of the study was to investigate the performance of IL-6 and IL-10 in febrile pediatric hematology/oncology patients with normal PCT. METHODS: This was a retrospective study conducted in a tertiary children's hospital in China over the past ten years. Inflammatory biomarkers, including IL-6, IL-10, PCT and C-reactive protein (CRP), were detected at the onset of infection. Separate analyses were conducted in patients with neutropenia and without neutropenia. RESULTS: In total, 5987 febrile cases were enrolled. For patients with neutropenia, IL-6, IL-10 and PCT were significantly increased in patients with bloodstream infection (BSI), gram-negative bacteremia (GNB) and severe sepsis (SS), but only IL-6 and IL-10 were predictive of GNB and SS. For patients without neutropenia, IL-6, IL-10 and PCT were significantly increased in patients with BSI, GNB and SS, but no biomarkers were predictive of adverse outcomes. All biomarkers failed to exclude patients with fever of unknown origin or upper respiratory infection/bronchitis in patients with neutropenia. CONCLUSIONS: IL-6 and IL-10 could be predictors for GNB and SS in febrile patients with neutropenia and had some association with unfavorable outcomes in febrile patients without neutropenia. All biomarkers failed to exclude patients with fever of unknown origin or upper respiratory infection/bronchitis.

A novel safer CD19CAR with shRNA interference of IFN-γ can reduce multiple cytokine levels without significantly compromising its killing efficacy.

Cytokine release syndrome (CRS) is a great challenge for the application of anti-CD19 CAR-T cell therapy. The aim of this study was to investigate the effect of knocking down interferon gamma (IFN-γ) by shRNA as a potential strategy to reduce the cytokine storms. A newly designed short hairpin interference RNA of IFN-γ (shIFN-γ) in CD19CAR gene was constructed. Several cellular model systems of approach using Nalm-6 cell lines including Nalm-6CD19pos and Nalm-6CD19neg with or without monocytes and endothelial cells were used to analyze the different levels of cytokines after shIFN-γ-anti-CD19CAR-T cell targeted therapy. The activity of this novel CD19CAR-T was evaluated both in vitro and in NSG mouse model. The killing efficacy of shIFN-γ-anti-CD19CAR-T at the E:T ratio of 2:1 was similar to that of regular anti-CD19CAR-T at the E:T ratio of 1:1. The IFN-γ level in the shIFN-γ-anti-CD19CAR-T cell group was (2673.1 ± 307.4) pg/ml at the E:T ratio of 2:1 which was significantly lower than that ((8261.5 ± 345.5) pg/ml) in the regular anti-CD19CAR-T group at the E:T ratio of 1:1. Cytotoxicity experiments in vitro showed significantly reduced concentrations of IFN-γ, IL-6 and TNFα in the shIFN-γ-anti-CD19CAR-T cell group compared to regular anti-CD19CAR-T cell group. Both regular anti-CD19CAR and shIFN-γ-CD19CAR-T exerted bystander killing effect in vitro. We conclude that shIFN-γ-anti-CD19CAR-T cells can reduce the generation of cytokine storms without significantly compromising their therapeutic efficacy in the preclinical setting. In mouse model, 3 × 106 shIFN-γ-anti-CD19CAR-T cells/mouse generated the similar killing efficacy to that with 2 × 106 regular anti-CD19CAR-T cells/mouse.

The effectiveness of blinatumomab in clearing measurable residual disease in pediatric B-cell acute lymphoblastic leukemia patients detected by next-generation sequencing.

BACKGROUND: Blinatumomab improved survival outcomes in B-cell acute lymphoblastic leukemia (B-ALL) patients with measurable residual disease (MRD) <10-4 . However, data on blinatumomab clearing MRD with high sensitivity of 10-6 remain scarce. This study evaluates the effectiveness of blinatumomab in eradicating extremely low level (up to <10-6 ) of MRD, as detected by next-generation sequencing (NGS), in children with B-ALL. METHODS: Patients (n = 19) whose MRD was undetectable by multiparameter flow cytometry (MFC) (sensitivity of 10-4 ) but detectable by NGS after chemotherapy and followed by blinatumomab consolidation were included retrospectively. RESULTS: After one course of blinatumomab, 13/19 patients (68%) successfully achieved NGS-MRD clearance (undetectable). With a median follow-up of 13.3 months, three of patients who were NGS-MRD positive relapsed within 1.8 months, while another three remained complete remission. CONCLUSIONS: Our study was the first to demonstrate that blinatumomab could further eradicate MRD after patients achieve MFC-MRD undetectable in B-ALL patients.

Minimal residual disease detection by next-generation sequencing of different immunoglobulin gene rearrangements in pediatric B-ALL.

While the prognostic role of immunoglobulin heavy chain locus (IGH) rearrangement in minimal residual disease (MRD) in pediatric B-acute lymphoblastic leukemia (B-ALL) has been reported, the contribution of light chain loci (IGK/IGL) remains elusive. This study is to evaluate the prognosis of IGH and IGK/IGL rearrangement-based MRD detected by next-generation sequencing in B-ALL at the end of induction (EOI) and end of consolidation (EOC). IGK/IGL rearrangements identify 5.5% of patients without trackable IGH clones. Concordance rates for IGH and IGK/IGL are 79.9% (cutoff 0.01%) at EOI and 81.0% (cutoff 0.0001%) at EOC, respectively. Patients with NGS-MRD < 0.01% at EOI or <0.0001% at EOC present excellent outcome, with 3-year event-free survival rates higher than 95%. IGH-MRD is prognostic at EOI/EOC, while IGK-MRD at EOI/EOC and IGL-MRD at EOI are not. At EOI, NGS identifies 26.2% of higher risk patients whose MRD < 0.01% by flow cytometry. However, analyzing IGK/IGL along with IGH fails to identify additional higher risk patients both at EOI and at EOC. In conclusion, IGH is crucial for MRD monitoring while IGK and IGL have relatively limited value.

A scoring system based on fusion genes to predict treatment outcomes of the non-acute promyelocytic leukemia pediatric acute myeloid leukemia.

Background: Fusion genes are considered to be one of the major drivers behind cancer initiation and progression. Meanwhile, non-acute promyelocytic leukemia (APL) pediatric patients with acute myeloid leukemia (AML) in children had limited treatment efficacy. Hence, we developed and validated a simple clinical scoring system for predicting outcomes in non-APL pediatric patients with AML. Method: A total of 184 non-APL pediatric patients with AML who were admitted to our hospital and an independent dataset (318 patients) from the TARGET database were included. Least absolute shrinkage and selection operation (LASSO) and Cox regression analysis were used to identify prognostic factors. Then, a nomogram score was developed to predict the 1, 3, and 5 years overall survival (OS) based on their clinical characteristics and fusion genes. The accuracy of the nomogram score was determined by calibration curves and receiver operating characteristic (ROC) curves. Additionally, an internal verification cohort was used to assess its applicability. Results: Based on Cox and LASSO regression analyses, a nomogram score was constructed using clinical characteristics and OS-related fusion genes (CBFß::MYH11, RUNX1::RUNX1T1, KMT2A::ELL, and KMT2A::MLLT10), yielded good calibration and concordance for predicting OS of non-APL pediatric patients with AML. Furthermore, patients with higher scores exhibited worse outcomes. The nomogram score also demonstrated good discrimination and calibration in the whole cohort and internal validation. Furthermore, artificial neural networks demonstrated that this nomogram score exhibits good predictive performance. Conclusion: Our model based on the fusion gene is a prognostic biomarker for non-APL pediatric patients with AML. The nomogram score can provide personalized prognosis prediction, thereby benefiting clinical decision-making.

Reduced regulatory effects of bone marrow-derived mesenchymal stem cells on activated T lymphocytes and Th1/Th2 cytokine secretion in children with aplastic anemia.

Acquired aplastic anemia (AA) is a recognized immune-mediated disorder and abnormally activated T lymphocyte-mediated bone marrow destruction is considered to be its main pathogenesis. Whether abnormal activation of T lymphocytes would also damage bone marrow-derived MSCs remains to be further studied. The aim of this study was to analyze the extent of T lymphocyte activation and the levels of Th1/Th2 cytokines of AA patients, and to explore the immunomodulatory effects of BM-MSCs on IL-2-stimulated T lymphocyte activation and cytokine production in vitro by means of transwell co-culture assay and flow cytometry measurement. The intermediate (CD25+) activated T cells were dominant in peripheral blood, while the early (CD69+) and late (HLA-DR+) activated T cells were predominant in bone marrow. Severe AA patients have an obviously higher proportion of CD3+CD8+CD69+ T cells than NSAA cases. The levels of IL-2 and IL-6 in AA patients were slightly elevated and INF-γ was mildly decreased in comparison with normal individuals. BM-MSCs derived from AA could not effectively inhibit the IL-2-induced activation of T cells with higher proportions of CD25+CD3+CD4+, CD69+CD3+CD4+ and CD25+CD3+CD8+ T cells after co-culture, and they showed a decreased ability to balance the Th1/Th2 cytokine production. Moreover, they had less robust osteogenic differentiation and more prone to adipogenic differentiation. We concluded that abnormally excessive T cell activation accompanied by abnormal cytokine secretion may impair the function of BM-MSCs in children with aplastic anemia.

[Role of Flow Cytometry in the Diagnosis of Chronic Myeloid Leukemia].

OBJECTIVE: To analyze the immunological phenotype of chronic myeloid leukemia (CML), and explore its characteristics and significance. METHODS: The immunophenotypes of 40 CML children and 40 controls were analyzed by multicolor flow cytometry. CD45/SSC, as the basic gate, was used to delineate neutrophils. Then, the distribution of cluster differentiation (CD) molecules on the surface of granulocytes was analyzed in three ranges (≥1%, ≥5%, and ≥20%), and the expression rates of CD molecules (≥1% included in the statistical analysis) and the mean fluorescence intensity (MFI) were compared between the two groups. RESULTS: The proportion of granulocytes in the CML group was (82.1±6.4)%, which was significantly higher than (57.8±11.8)% in the control group (P <0.001). The expression rates of CD15/CD11b/CD33/CD13 in CML and control groups were high, and both distributed in the range of ≥20%. The differentiation trajectory of CD33/CD13 was normal and there were no significant differences in the expression rate and MFI between the two groups. However, both the expression rate of CD11b and CD15 MFI in the CML group were significantly lower than those in the control group (P <0.001). There were no significant differences in the expression rate and MFI of CD10 between the two groups, and the expression levels of CD10 between the two groups were consistent in different distributions. In the CML group, there was a large number of cases with abnormal high expression of CD56, 52.5% of the cases had a CD56 expression rate of ≥5%, and 42.5% had a CD56 expression rate of ≥20%, while the control group did not express CD56 (<1%). The expression distribution of CD117 was different between the two groups. In the range of expression rate ≥5%, there were 35.0% cases in the CML group, while only 2.5% in the control group. The expression rate of CD117 in the CML group was higher than that in the control group (P <0.001), though there was no significant difference in MFI. CONCLUSION: The immunophenotyping of CML is characterized by increased proportion of mature neutrophils, decreased CD15 MFI, decreased proportion of CD11b and abnormal high expression of CD56 and CD117. Flow cytometric analysis of immunophenotype can effectively distinguish normal granulocytes from chronic granulocytes, and help in the diagnosis of CML.

[Effect of Human Bone Marrow Mesenchymal Stem Cells with Ectopic High OCT4 Expression on T Lymphocyte Function].

OBJECTIVE: To explore the effect of human bone marrow mesenchymal stem cells (MSCs) with ectopic high OCT4 expression on T-cell proliferation, activation and secretion in vitro. METHODS: Peripheral blood mononuclear cells were isolated from healthy children. Anti-CD3 and anti-CD28 monoclonal antibodies were used to activate T lymphocytes, which were stimulated by interleukin (IL)-2 for one week in vitro. Then MSCs with ectopic high OCT4 expression (MSC-OCT4) were co-cultured with activated T lymphocytes. After one week of co-culture, the supernatant was collected and the levels of Th1/Th2 cytokines [IL-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α and interferon (IFN)-γ] were determined by flow cytometry. The lymphocytes after one week of co-culture were collected and counted by Countstar software. After the proportions of activated/inactivated T cell subsets were determined by flow cytometry, the absolute lymphocyte counts were calculated and expressed as mean ± standard deviation. RESULTS: Compared with control T cell alone culture group, the proliferation of CD3+ T cells, CD3+CD4+ T cells, and CD3+CD8+ T cells were significantly inhibited in MSC group and MSC-OCT4 group. Compared with MSC, MSC-OCT4 could inhibit CD3+CD8+ T cell proliferation better (P =0.049), and mainly inhibited early T cell activation. Compared with control T cell alone culture group, the levels of IL-2 and INF-γ were significantly down-regulated both in MSC group and MSC-OCT4 group.After co-culture with T cells for one week, the level of IL-6 significantly increased in MSC group and MSC-OCT4 group compared with that before co-culture. Compared with control MSC group, MSC-OCT4 group had higher viable cell numbers after 1 week of co-culture (P =0.019), and could resist the inhibition of proliferation by higher concentration of mitomycin C. CONCLUSION: Both MSC and MSC-OCT4 can inhibit the proliferation and activation of IL-2-stimulated T cells in vitro. After overexpression of OCT4, MSC has better proliferation ability in vitro and can inhibit the proliferation of CD3+CD8+ T cells more effectively, which may have a better and more lasting immunosuppressive ability to regulate the balance of Th1/Th2.

Comparative study of biomarkers for the early identification of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in infectious mononucleosis.

BACKGROUND AND AIM: Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) and infectious mononucleosis (EBV-IM) share mimic symptoms in the early stages of childhood development. We aimed to examine the clinical features and laboratory indices of these two diseases in children and uncover unique indicators to assist pediatricians in identifying these diseases early. METHODS: We collected clinical data from 791 pediatric patients diagnosed with EBV-IM or EBV-HLH, compared the clinical traits and laboratory biomarkers presented in the two groups, and constructed predictive models based on them. RESULTS: Patients with EBV-IM had greater ratios of cervical lymphadenopathy, eyelid edema, and tonsillitis, whereas individuals with EBV-HLH were more likely to have hepatomegaly and splenomegaly. When using the criteria of interleukin (IL)-10 > 89.6 pg/mL, interferon (IFN)-γ > 45.6 pg/mL, ferritin > 429 µg/L, D-dimer > 3.15 mg/L and triglycerides > 2.1 mmol/L, the sensitivity was 87.9%, 90.7%, 98.1%, 91.1% and 81.5% to predict EBV-HLH, while the specificity was 98.4%, 96.3%, 96.5%, 94.1% and 80.6%, respectively. A logistic regression model based on four parameters (IL-10, ferritin, D-dimer, and triglycerides) was established to distinguish EBV-HLH patients from EBV-IM patients, with a sensitivity of 98.0% and a specificity of 98.2%. CONCLUSIONS: IL-10, IFN-γ, ferritin and D-dimer levels are significantly different between EBV-HLH and EBV-IM. Predictive models based on clinical signs and laboratory findings provide simple tools to distinguish the two situations.