[Expression and Significance of PD-1 and ICOS in Patients with Primary Immune Thrombocytopenia].

OBJECTIVE: To investigate the expression of programmed death receptor-1 (PD-1) and inducible costimulator (ICOS) on the surface of CD8+ T cells in peripheral blood of patients with primary immune thrombocytopenia (ITP), and explore the roles of PD-1 and ICOS in the occurrence and development of ITP. METHODS: A total of 28 ITP patients treated in Tianjin Medical University General Hospital from September to December 2020 were selected, including 13 patients with newly diagnosed ITP, 15 patients with chronic ITP, and 22 healthy volunteers were recruited as control group. Flow cytometry was used to detect the expression levels of PD-1 and ICOS, and evaluate their correlation with clinical indicators. RESULTS: The percentage of CD8 + T cells in ITP patients of chronic group was higher than that of the newly diagnosed group and the control group (P<0.05). The expression level of PD-1 on CD8+ T cells in ITP patients of newly diagnosed group and chronic group were significantly lower than that of the control group (P<0.05), while the expression level of ICOS were significantly higher (P<0.05). In ITP patients, PD-1 was negatively correlated with platelet count (r=-0.4942, P<0.01), but positively with ICOS (r=0.4342). PD-1 and ICOS were both negatively correlated with lymphocyte count (rPD-1=-0.4374; rICOS=-0.4492). CONCLUSION: In ITP patients, the unbalanced expression of PD-1 and ICOS may interfere with the immune homeostasis of the body, which can be used as a therapeutic target for ITP patients.

Developing and validating a mortality prediction model for ICH in ITP: a nationwide representative multicenter study.

Intracranial hemorrhage (ICH) is a rare and life-threatening hemorrhagic event in patients with immune thrombocytopenia (ITP). However, its mortality and related risk factors remain unclear. Herein, we conducted a nationwide multicenter real-world study of ICH in adult ITP patients. According to data from 27 centers in China from 2005 to 2020, the mortality rate from ICH was 33.80% (48/142) in ITP adults. We identified risk factors by logistic univariate and multivariate logistic regression for 30-day mortality in a training cohort of 107 patients as follows: intraparenchymal hemorrhage (IPH), platelet count ≤10 × 109/L at ICH, a combination of serious infections, grade of preceding bleeding events, and Glasgow coma scale (GCS) level on admission. Accordingly, a prognostic model of 30-day mortality was developed based on the regression equation. Then, we evaluated the performance of the prognostic model through a bootstrap procedure for internal validation. Furthermore, an external validation with data from a test cohort with 35 patients from 11 other centers was conducted. The areas under the receiver operating characteristic (ROC) curves for the internal and external validation were 0.954 (95% confidence interval [CI], 0.910-0.998) and 0.942 (95% CI, 0.871-1.014), respectively. Both calibration plots illustrated a high degree of consistency in the estimated and observed risk. In addition, the decision curve analysis showed a considerable net benefit for patients. Thus, an application (47.94.162.105:8080/ich/) was established for users to predict 30-day mortality when ICH occurred in adult patients with ITP.

[Inhibitory Effect of Ascorbic Acid on Myelodysplastic Syndrome Cells and Its Mechanism].

OBJECTIVE: To investigate the inhibitory effect of ascorbic acid single or combination of decitabine on tumor cells of myelodysplastic syndrome (MDS) and explore its related mechanism. METHODS: The human MDS cell lines SKM-1 and MUTZ-1 were treated with different concentrations of ascorbic acid, and the cell proliferation activity was detected by the CCK-8 assay. The reactive oxygen species (ROS) level, labile iron pool (LIP), cell cycle, and apoptosis of SKM-1 and MUTZ-1 cells were detected by flow cytometry. The control group, ascorbic acid monotherapy group, decitabine monotherapy group, and combination group of ascorbic acid and decitabine were set up, the cell proliferation activity and apoptosis were detected in each group. RESULTS: High-dose ascorbic acid could reduce the cell proliferation activity of SKM-1 (R=0.886, p=0.000) and MUTZ-1 (R=0.880, p=0.000). With the increase of ascorbic acid concentration, the ROS level in SKM-1 and MUTZ-1 cells increased (r=0.816, r=0.942), the proportion of cells stagnation in G2 phase increased (r=0.970, p=0.000; r=0.962, p=0.000), the proportion of surviving cells decreased (r=-0.966, p=0.000; r=-0.952, p=0.000), and the apoptosis cells significantly increased (r=0.966, p=0.000; r=0.958, p=0.000). Nevertheless, the level of LIP showed no significant changes. After the combined application of ascorbic acid and decitabine, MDS tumor cells showed decreased proliferative activity and increased apoptosis compared with single-agent ascorbic acid and decitabine group. CONCLUSION: High-dose ascorbic acid shows a cytotoxic effect on MDS tumor cells, inhibiting cell proliferation and increasing apoptosis. Ascorbic acid combined decitabine have a synergistic effect of anti-MDS tumor cells.

[Research Progress on Pathogenesis of Congenital Pure Red Cell Aplasia---Review].

Congenital pure red cell aplasia, also known as Diamond-Blackfan anemia (DBA), is a hereditary disease characterized by pure red cell aplasia and congenital malformation. Its main clinical features are anemia, dysplasia, and tumor susceptibility. Ribosomal protein (RP) gene mutation is the main pathogenesis of DBA. The most common type of gene mutation is RPS19 gene mutation. Heterozygous mutations in as many as 19 RP genes and other non-RP genes mutations have been identified in DBA. This review summarized briedfly the latest research advances in the pathogenesis of DBA.

Risk stratification and outcomes of intracranial hemorrhage in patients with immune thrombocytopenia under 60 years of age.

Intracranial hemorrhage (ICH) is a devastating complication of immune thrombocytopenia (ITP). However, information on ICH in ITP patients under the age of 60 years is limited, and no predictive tools are available in clinical practice. A total of 93 adult patients with ITP who developed ICH before 60 years of age were retrospectively identified from 2005 to 2019 by 27 centers in China. For each case, 2 controls matched by the time of ITP diagnosis and the duration of ITP were provided by the same center. Multivariate analysis identified head trauma (OR = 3.216, 95%CI 1.296-7.979, P =.012), a platelet count ≤ 15,000/µL at the time of ITP diagnosis (OR = 1.679, 95%CI 1.044-2.698, P =.032) and severe/life-threatening bleeding (severe bleeding vs. mild bleeding, OR = 1.910, 95%CI 1.088-3.353, P =.024; life-threatening bleeding vs. mild bleeding, OR = 2.620, 95%CI 1.360-5.051, P =.004) as independent risk factors for ICH. Intraparenchymal hemorrhage (OR = 5.191, 95%CI 1.717-15.692, P =.004) and a history of severe bleeding (OR = 4.322, 95%CI 1.532-12.198, P =.006) were associated with the 30-day outcome of ICH. These findings may facilitate ICH risk stratification and outcome prediction in patients with ITP.

[Relationship of Peripheral Blood IL-37 Expression with T Lymphocytes Subsets and NK Cells in Patients with Primary Immune Thrombocytopenia].

OBJECTIVE: To study the correlation of IL-37 with T lymphocytes subsets and NK cells in ITP patients, and to explore its possible mechanisms involved in the pathogenesis of ITP. METHODS: Forty-five patients with newly diagnosed ITP(newly diagnosed group), 32 patients of complete remission (remission group) and 22 healthy persons(control group) were selected. The serum level of IL-37 in 3 groups was determined by enzyme linked immunosorbent assay (ELISA). The mRNA expression of IL-37, IL-17 and IL-18 in peripheral blood mononuclear cells（PBMNC） in 3 groups was measured by real-time fluorescence quantitative polymerase chain reaction (PCR). The number of IL-18Rα+CD4+ T cells and Tim-3+NK cells in the peripheral blood in 3 groups was detected by flow cytometry (FCM). RESULTS: The serum level of IL-37 in the peripheral blood of ITP patients in the newly diagnosed group was significantly higher than that in the control group and the remission group(P＜0.01) . The expression level of IL-37 in PBMNC of the ITP patients in newly diagnosed group was higher than that in the control group and the remission group(P＜0. 05). The expression level of IL-17 and IL-18 in PBMNC of the ITP patients in newly diagnosed group was higher than that in the control group and the remission group(P＜0. 01); the expression of IL-18Rα in CD4+ T cells in newly diagnosed group was significantly higher than that in both the control and the remission group(P＜0.01).The expression of Tim-3 in NK cells in ITP patients was significantly lower than that in the control group (P＜0. 01). In ITP patients, the serum IL-37 level and IL-18Rα+CD4+T cells ratio both negatively correlated with Plt count (r=-0.58, r=-0.48) moreo-ver the serum IL-37 level also negatively correlated with amount of CD4+ T cells and NK cells (r=-0.29, r=-0.28), but positively correlated with amount of CD8+ T cells (r=0.329). CONCLUSION: The IL-37 and its receptors may play an immunoregulatory role in CD4+ T cells and NK cells, the IL-37 may be a therapeutic target for ITP patients.

[Subtype and Functional Biomarker Changes of NK Cells in Peripheral Blood of Patients with Myelodysplastic Syndrome].

OBJECTIVE: To analyze the subtype and functional biomarker expression changes of natural kill cells(NK) in peripheral blood of patients with myelodysplastic syndrome(MDS) and normal people, so as to evaluate the relationships between these changes and hematopoietic functions and to explore the role of NK cells in the pathogenesis of MDS. METHODS: The quantity of NK cells and the expression of biomarkers(NKp30,NKp46,NKG2A) on NK cells were detected by flow cytometry in 35 MDS patients from 2015 to 2016 in our hospital and 34 normal controls. The correlation between these changes and hematopoietic functions, including the percentages of neutrophil(ANC), hemoglobin in peripheral blood and the hematopoietic function in bone marrow(CD34+%) were evaluated. RESULTS: The percentage and quantity of NK cells and CD56dim NK cells in MDS patients were significantly lower than those in normal controls(P<0.05); the percentage of CD56bright NK cells was higher than that in controls. The percentage of CD56dim NK cells in NK cells of MDS patients was significantly lower than that of controls; the percentage of CD56bright NK cells in NK cells of MDS patients was significantly higher than that of controls. The expression of NKp30 and NKp46 of MDS patients was significantly lower than that of controls. In MDS group, the percentage of NK cells and CD56dim NK cells of peripheral blood lymphocytes in high risk MDS group was significantly lower than that in low risk MDS group. The percentage of NK and CD56dim NK cells negatively correlated with that of CD34+% in bone marrow, but positively correlated with ANC and Hb. The CD34+% in bone marrow negatively correlated with expression of NKp46, but positively correlated with expression of NKG2A. CONCLUSION: The decrease of NK number and function may cause the immune surveillance and lead to disease progression.

[Single Nucleotide Polymorphism of Mitochondrial DNA D-LOOP Region in Peripheral Blood Lymphocytes of Immuno-related Pancytopenia Patients].

OBJECTIVE: To explore the single nucleotide polymorphism(SNP) of mitochondrial DNA (mtDNA) D-LOOP region in peripheral blood lymphocytes of immuno-related pancytopenia (IRP) patients and its correlation with immune parameters. METHODS: The D-LOOP region in mitochondrial DNA of lymphocytes in peripheral blood mononuclear cells from 43 patients with untreated IRP was detected by polymerase chain reaction(PCR). The PCR products were sequenced by the pros and cons direct sequencing methods. The sequencing results were compared with the revised Cambridge reference sequence (rCRS) and the Polymorphic Sites of Human Mitochondrial Genome Database. RESULTS: Among total of 110 variant positions of D-LOOP region in 43 patients, 62 was SNP sites and 48 was mutation sites, of which 14 were the new mutation sites not yet registered in the database, 516 base variations were observed at 110 positions, the most common variations were base substitutions, among them T/C and A/G was 184/410 and 113/410 respectively. In the 110 variant positions, the high frequency variation sites were 73 and 263 for 43/43,311 for 32/43,310 and 16 224 for 27/43,16 519 for 25/43, 489 and 16 362 for 24/43. By the analysis of mitochondrial DNA D-LOOP polymorphism and related clinical immunology indicators of the patient's lymphocytes, it was found that D-loop in adult patients (age≥ 18 years old) significantly correlated with CD15 IgM, GLYCoA+ Cells IgM, CD34+ CellsIgG, CD34+ Cells IgM correlation. CONCLUSION: The high frequency of polymorphism exists in mitochondrial DNA D-loop region of lymphocytes in IRPA patients, and was significantly correlates with the autoantibodies in bone marrow mononuclear cells in adult patients, which may be associated with the IRP occurrence.

[Expression and Significance of HOXA9 in Patients with Myelodysplastic Syndromes].

OBJECTIVE: To investigate the expression pattern of HOXA9 in myelodysplastic syndrome (MDS) patients and its relation with clinical characteristics and treatment response. METHODS: The mRNA and protein expression levels of HOXA9 in bone marrow cells from 33 cases of MDS, 12 cases of AML, 20 cases of ITP and 18 normal controls were detected by real-time guautitative PCR(RT-PCR) and flow cytometry, respectively. RESULTS: The percentage of HOXA9(+)/CD34(+) and HOXA9(+)/CD34(+)CD38(-) in MDS patients were significantly higher than that in control group (P<0.05), and the mRNA and protein expression of HOXA9 in MDS patients had a similar trend. The percentages of HOXA9(+)/CD34(+) and HOXA9(+)/CD34(+)CD38(-) before decitabine treatment were (50.64±27.59)% and (55.67±28.57)% respectively, which were both higher than those in control group (P<0.05). After decitabine treatment, expression of HOXA9 significantly decreased (P<0.05). CONCLUSION: HOXA9 is overexpressed in MDS patients and associated with several clinical characteristics. The detection of HOXA9 expression may have guide roles for diagnosis and treatment of MDS patients.

[Influence of Costimulatory Signaling Molecules on Immun Functons of B Lymphocytes in Patients with Immune Thrombocytopenia].

OBJECTIVE: To explore the effect of costimulatory signaling molecules (CD80, CD86) expression on the quantity and function of B lymphocytes in peripheral blood (PB) of the patients with immune thrombocytopenia (ITP). METHODS: A total of 55 ITP patients (30 cases were newly diagnosed and 25 cases were in remission), 25 healthy volunteers as controls were enrolled in this study. The levels of CD19(+)CD5(+), CD19(+)CD80(+), CD19(+)CD86(+), CD41a(+)IgG, CD41a(+)IgM and IgG, IgM in CD19(+)B cells were measured by flow cytometry (FCM). The correlation of CD19(+)B cells with clinical parameters of ITP patients was analyzed. RESULTS: The level of B1 (CD19(+)CD5(+)) of newly diagnosed ITP patients was significantly higher than that of remitted ITP patients and controls (P<0.05). The level of CD19(+)CD80(+) of newly diagnosed ITP patients was significantly higher than that of remitted ITP patients and controls (P<0.05). And the expression of IgG and IgM in CD19(+)B cells of newly diagnosed ITP patients was significantly higher than that of remitted ITP patients and controls (P<0.05). The levels of IgG and IgM in remitted ITP patients after treatment were significantly lower than that before treatment (P<0.05). The level differences of IgG and IgM before and after treatment in refractory ITP patients were not statistically significant (P>0.05). The expression of CD19(+)CD80(+) in newly diagnosed ITP patients positively correlated with the level of Th1 and Th1/Th2 (r=0.502, r=0.471, P<0.05). The expression of CD19(+)CD80(+) of newly diagnosed ITP patients positively correlated with the level of IgG and IgM in CD19(+)B cells (r=0.552, r=0.467, P<0.05), and negatively correlated with PB platelet count (r= -0.424, P<0.05). The levels of IgG and IgM in CD19(+)B cells of newly diagnosed ITP patients negati- vely correlated with PB platelet count (r=-0.658, r=-0.526, P<0.05). CONCLUSION: The enhacement of costimulatory signaling pathway of CD19(+)B cells in ITP patients results in the abnormal activation of B lymphocytes, thereby mediates the dysfunction of immune system and involves in the pathogenesis of ITP.

[Bone Marrow Microenvironment and Myelodysplastic Syndromes--Review].

Myelodysplastic syndromes (MDS) are a group of bone marrow failure diseases. The bone marrow microenvironment consists of bone marrow stromal cells (BMSC), growth factors and cytokines. The BMSC supporting haemopoiesis include mesenchymal stem cells (MSC), osteoblasts, endothelial cells and macrophages, but the adipocytes play a role in the suppression of hematopoiesis. Recently more and more researches indicate that the abnormality of bone marrow microenvironment involves in the pathogenesis and progression of MDS. In this review the abnormality of MDS bone marrow microenvironment is summarized briefly.

[Follicular Helper T Cells and Expression of PD-1 in Mice with Myelodysplastic Syndrome].

OBJECTIVE: To investigate the complete blood count, morphological changes, follicular T helper (Tfh) cells and expression of PD-1 in bone marrow and spleen of mice with myelodysplastic syndrome(MDS) and to explore their significance in pathogenesis of MDS. METHODS: The 10 male NUP98-HOXD13 transgenic mice and 10 male homologous wild-type C57BL/6J mice were used for experments. The complete blood count, morphological change of NUP98-HOXD13 transgenic mice and wild-type C57BL/6J were detected by routine methods. The level of Tfh cells and expression of PD-1 in bone marrow and spleen were measured by flow cytometry. The PD-1 mRNA of bone marrow mononuclear cells and spleen cells were analyzed by real-time PCR method. RESULTS: The counts of RBC, neutrophile and platelet in above- mentioned transgenic mice were less than that in wild type C57BL/6J mice. As compared with wild type C57BL/6J mice, the morphology of RBC and platelet in transgenic mice was some abnormal, including bi-nucleated erythrocytes, ringed mucleated neutrophil and erythroblastic islands. The count of Tfh cells in transgenic mice was less than that in wild type mice, but the expression of PD-1 was higher. The expression of BMMNC PD-1 mRNA was obviously higher than that in wild type mice. CONCLUSION: The pancytopenia and dysplasia, decrease of Tfh cells and increase of PD-1 expression have been observed in NUP98-HOXD13 transgenic mice, which may be one of important reasons for promoting malignant clone and leading to impair anti immune respones.

[Abnormal quantity of regulatory T cells in peripheral blood of patients with severe aplastic anemia and its clinical significance].

This study was purposed to investigate the role of regulatory T cells (Treg) in the immune unbalance for patients with acquired severe aplastic anemia (SAA). The flow cytometry was used to detect the quantity of CD4(+) CD25(+) CD127(dim) Tregs, T cell subset (CD4(+)/CD8(+) ratio), dendritic cell(DC) subset(mDC/pDC ratio) in 44 SAA patients(25 untreated patients and 19 recovery patients) and 23 normal controls. The correlation between Tregs and T cell subset, DC subset and hemogram were analyzed. The results showed that the percentage of CD4(+) CD25(+) CD127(dim) Tregs in peripheral blood lymphocyte(PBL) of untreated patients was (0.83 ± 0.44) %, which was obviously lower than that in recovery patients (2.91 ± 1.24)% and normal controls (2.18 ± 0.55)% (P < 0.05), but the difference was not statistically significant between latter two groups. The ratio of CD4(+)/CD8(+) was (0.5 ± 0.3) in untreated patients, which was obviously lower than that in recovery patients (1.2 ± 0.4) and normal controls (1.11 ± 0.24) (P < 0.05). The ratio of mDC/pDC was (3.08 ± 0.72) in untreated patients, which was significantly higher than that in recovery patients(1.61 ± 0.49) and normal controls (1.39 ± 0.36) (P < 0.05). The percentage of CD4(+) CD25(+)CD127(dim) Tregs in PBL positively correlated with CD4(+)/CD8(+) ratio (r = 0.695, P < 0.01), and that negatively correlated with mDC/pDC ratio (r = -0.796, P < 0.01). There were significant positive correlations between CD4(+)CD25(+)CD127(dim) Tregs/PBL and WBC, Ret% (r = 0.761, 0.749 respectively, P < 0.01). It is concluded that the decrease of CD4(+)CD25(+)CD127(dim) Tregs quantity in SAA may be one of mechanisms underlying bone marrow failure resulting from the deterioration of immune tolerance and hyperfunction of T-cells.

[Quantity and function of T follicular helper cells in the bone marrow of patients with immune thrombocytopenia].

This study was purposed to detect the quantity and function of bone marrow (BM) T follicular helper (Tfh) cells of patients with immune thrombocytopenia, and to explore the role of Tfh cells in the pathogenesis of ITP. Twenty-one newly diagnosed ITP patients, twenty ITP patients in recovery stage and eighteen normal controls were enrolled in this study. The percentages of Tfh cells, Tfh-related molecules ICOS, CD40L, IL-21 in BM were detected by flow cytometry (FCM), and the mRNA expression of BCL-6 in BMMNC was determined by semi-quantitive RT-PCR. Correlation of Tfh cell level with the disease severity of ITP patients was analysed. The results showed that the ratio of CD4(+)CXCR5(+)/CD4(+) cells in newly diagnosed ITP patients [(5.532 ± 2.599)%] was significantly higher than that in ITP patients with recovery stage [(4.064 ± 2.026)%] and controls [(4.048 ± 1.413)%] (P < 0.05). The ratio of CD4(+)CXCR5(+)ICOS(+)/CD4(+) CXCR5(+) cells in newly diagnosed ITP patients [(14.586 ± 8.561)%] was higher than that in recovery stage ITP patients [(12.884 ± 10.161)%] and controls [(7.487 ± 5.176)%]. The differences be-tween newly diagnosed ITP patients and controls were statistically significant (P < 0.05). The ratio of CD4(+)CXCR5(+) CD40L(+)/CD4(+) CXCR5(+) cells in newly diagnosed ITP patients [(15.309 ± 10.756)%] and in ITP patients with recovery stage [(18.242 ± 12.243)%] were significantly higher than that in controls [(8.618 ± 5.719) %] (P < 0.05). The ratio of intracytoplasm CD4(+) CXCR5(+) IL-21(+)/CD4(+)CXCR5(+) cells in newly diagnosed ITP patients [(58.560 ± 26.285)%] and in ITP patients with recovery stage [(57.035 ± 30.936)%] were significantly higher than that in controls [(36.289 ± 24.868)%] (P < 0.05). The relative expression levels of BCL-6 mRNA in BMMNC of three groups were (1.407 ± 0.264), (1.149 ± 0.217) and (0.846 ± 0.157), respectively. The differences between 3 groups were significant(P < 0.05). It is concluded that the quantity and function of Tfh cells in ITP patients increase, which may play an important role in the pathogenesis of ITP.

Expression of Shelterin component POT1 is associated with decreased telomere length and immunity condition in humans with severe aplastic anemia.

Abnormal telomere attrition has been found to be closely related to patients with SAA in recent years. To identify the incidence of telomere attrition in SAA patients and investigate the relationship of telomere length with clinical parameters, SAA patients (n=27) and healthy controls (n=15) were enrolled in this study. Telomere length of PWBCs was significantly shorter in SAA patients than in controls. Analysis of gene expression of Shelterin complex revealed markedly low levels of POT1 expression in SAA groups relative to controls. No differences in the gene expression of the other Shelterin components-TRF1, TRF2, TIN2, TPP1, and RAP1-were identified. Addition of IFN-γ to culture media induced a similar fall in POT1 expression in bone marrow cells to that observed in cells cultured in the presence of SAA serum, suggesting IFN-γ is the agent responsible for this effect of SAA serum. Furthermore, ATR, phosphorylated ATR, and phosphorylated ATM/ATR substrate were all found similarly increased in bone marrow cells exposed to SAA serum, TNF-α, or IFN-γ. In summary, SAA patients have short telomeres and decreased POT1 expression. TNF-α and IFN-γ are found at high concentrations in SAA patients and may be the effectors that trigger apoptosis through POT1 and ATR.

Increased CD34+CD38 -CD123 + cells in myelodysplastic syndrome displaying malignant features similar to those in AML.

Leukocyte interleukin-3 receptor α (CD123) is regarded as a marker of leukemia stem cells. We previously found that CD123 was also highly expressed on CD34(+)CD38(-) cells in myelodysplastic syndrome (MDS) patients, but it is unclear whether the level and the characteristics of CD34(+)CD38(-)CD123(+) cells in MDS are similar to those in acute myeloid leukemia (AML). Based on previous research by our team, we further enlarged the specimens and found that the mean proportion and the mean MFI of CD34(+)CD38(-)CD123(+) cells in low-grade MDS were lower than that in AML, and those in high-grade MDS were similar to those in AML. CD34(+)CD38(-)CD123(+) cells expressed lower granulocyte stimulating factor receptor, CD11b, and apoptosis molecule (Annexin V), meanwhile, these cells showed upregulation of transcription factors (GATA-1, GATA-2) and transferrin receptor (CD71) in MDS and AML. Furthermore, an increase in CD34(+)CD38(-)CD123(+) cells was closely related to the number of cytopenias involving hematopoietic lineages, anemia, blast count in bone marrow smear, fluorescence in situ hybridization analysis and WHO prognostic scoring system score. Thus, increases in CD34(+)CD38(-)CD123(+) cells may reflect malignant clonal cells with aberrant differentiation, overproliferation, and decreased apoptosis in MDS, which were similar to AML. CD123 may thus be a promising indicator for identifying malignant clonal cells in MDS and a candidate for targeted therapy.

Elevated TIM3+ hematopoietic stem cells in untreated myelodysplastic syndrome displayed aberrant differentiation, overproliferation and decreased apoptosis.

TIM3, as a negative regulator of anti-tumor immunity, is highly expressed on LSCs, but not on normal HSCs. TIM3 on HSCs in MDS patients has not been clarified. Here, both the percentage of TIM3 on HSCs and the MFI of TIM3+ HSCs were higher in untreated MDS than control and were closed to AML, and excessive TIM3+ HSCs was closely related to clinical parameters: WPSS score, karyotype analysis, morphologic blasts, the number of cytopenia involving hematopoietic lineages, anemia and granulocytopenia. TIM3+ HSCs expressed lower CD11b, TpoR, EpoR, G-CSFR and Annexin V, and higher CD71 and GATA2. TIM3+ HSCs displayed aberrant differentiation, overproliferation and decreased apoptosis. TIM3 might be a promising marker for identifying malignant clone cells in MDS and a candidate for targeted therapy.

[Expression and clinical significance of miR-21 in diffuse large B cell lymphoma].

This study was aimed to investigate the expression of microRNA-21 and its correlation with PTEN in diffuse large B cell lymphoma (DLBCL) paraffin-embedded tissues, and evaluate its potential relevance with clinical characteristics. The expression levels of miR-21 in 26 primary DLBCL and 10 normal lymph node tissue specimens were examined by real-time polymerase chain reaction. The expression of PTEN was detected by immunohistochemical staining. The results indicated that the expression of miR-21 was significantly higher in tumor tissues [6.586(1.10,38.22)] than that in normal tissues [0.791 (0.35,2.87)] (P < 0.05). Among 26 patients with DLBCL the expression of PTEN protein was positive in 6 patients (23%), and was negative in 20 patients (77%). In patients with DLBCL, the expression level of miR-21 was negatively correlated with the level of PTEN protein. The high expression of miR-21 was positively correlated with the level of serum LDH. The expression level of miR-21 in patients with Ann Arbor III-IV stage was obviously higher than that of patients with Ann Arbor I-II stage, but did not correlate with the subtype of patients in clinic (P > 0.05). It is concluded that the expression of miR-21 is high in DLBCL and its overexpression may be related with poor prognosis of DLCBL. These findings suggest that PTEN is possibly one of the targets of miR-21 in DLBCL.

[Study on the dendritic cell subsets in peripheral blood and its relationship with the expressions of Gata-3 and T-bet in lymphocytes of patients with immune thrombocytopenia].

OBJECTIVE: To explore the relationship between the dendritic cell (DC) subsets and abnormal expression of transcription factors Gata-3 and T-bet in patients with immune thrombocytopenia (ITP). METHODS: The plasmacytoid DC (pDC) and myeloid DC (mDC) of 33 ITP (16 untreated, 17 remitted) patients and 12 healthy controls were analyzed by flow cytometry (FCM) . The expressions of Gata-3 mRNA and T-bet mRNA in peripheral blood mononuclear cell (PBMNC) were detected by reverse transcription-polymerase chain reaction (RT-PCR) .The levels of interleukin-4 (IL-4) and interferon-gamma (IFN-γ) were measured by FCM in 33 ITP patients and 12 healthy controls. RESULTS: The percentage of pDC in PBMNC was 0.49% ± 0.18% in untreated and it was higher than that in remitted ITP patients (0.27% ± 0.17%) and in controls (0.32% ± 0.13%) (both P < 0.05). The percentage of mDC in PBMNC was 0.23% ± 0.17% in untreated, which was lower than that in remitted ITP patients (0.33% ± 0.18)% and in controls (0.31% ± 0.11%), but no statistic difference in mDC expression existed among 3 groups (P > 0.05). pDC/mDC ratios was (3.15 ± 2.01) in untreated ITP patients and it was higher than that in remitted ITP patients (0.81 ± 0.32) and in controls (1.07 ± 0.44) (both P < 0.05). The relative mRNA expression levels of Gata-3 were 2775 ± 489, 1357 ± 307 and 652 ± 165 respectively. And the expression of Gata-3mRNA in untreated group was higher than that in remission group or healthy controls (both P < 0.05). The relative mRNA expression levels of T-bet were 782 ± 394, 583 ± 176 and 576 ± 120. No statistic difference in T-bet expression existed among 3 groups (P > 0.05). Gata-3mRNA/T-bet mRNA ratio was (4.13 ± 1.69 ) in untreated group and it was higher than that of remission group (2.45 ± 0.69) or controls (1.15 ± 0.27) (both P < 0.05). The level of IL-4 in the untreated group was 9.14% ± 4.34% and it was higher than that of remission group (4.78% ± 1.69%) or controls (4.86% ± 1.41%). The level of IFN-γ in the untreated group was lower than that of controls (P < 0.05). Significant positive correlations existed between Gata-3 and pDC/mDC ratio (r = 0.585, P < 0.01). Significant positive correlations existed between Gata-3 and IL-4 ( r = 0.463, P < 0.05). CONCLUSION: The mechanism of ITP may be due to a disorder of DC subsets and a high expression of Gata-3.

[Telomere length and gene expression of shelterin in CD3(+) T cell of severe aplastic anemia patients].

OBJECTIVE: To explore the changes in telomere length and gene expression of complex shelterin (composed of 6 core components: TRF1, TRF2, POT1, TIN2, TPP1 and RAP1) in severe aplastic anemia (SAA). METHODS: Bone marrow samples were obtained from 20 SAA patients and 10 normal controls. CD3(+)T cells were sorted by immunomagnetic separation. Telomere length was tested by Southern blot and the gene expressions of TRF1, TRF2, POT1, TIN2, TPP1 and RAP1 were detected by reverse transcription-PCR(RT-PCR). RESULTS: Telomeres of CD3(+)T cells were found significantly shorter in SAA untreated ((4.4 ± 1.1) kb, n = 9) and recovering groups((5.8 ± 1.0) kb, n = 11) than control group ((9.2 ± 3.3) kb, P < 0.05). Telomere length of CD3(+)T cells shortened with TH/S decreasing (r = 0.564, P = 0.029). The mRNA expression of POT1 decreased in untreated SAA patients (0.16(0.02-0.29)) and over-expressed in recovering patients (1.17(0.82-1.86), P < 0.05). The mRNA expression of RAP1 was significantly higher in untreated patients (4.14 (1.93-6.92)) than that in recovering group (0.87 (0.30-1.73) ) and controls (0.62 (0.45-4.07) , both P < 0.05). CONCLUSION: Changes in telomere length and shelterin gene expression occur in CD3(+)T cells of SAA patients and may be correlated with disease severity.