[Stable Expression of Coagulation Factors by RPS6 Promoter].

OBJECTIVE: To screen better promoters and provide more powerful tools for basic research and gene therapy of hemophilia. METHODS: Bioinformatics methods were used to analyze the promoters expressing housekeeping genes with high abundance, so as to select potential candidate promoters. The GFP reporter gene vector was constructed, and the packaging efficiency of the novel promoter was investigated with EF1 α promoter as control, and the transcription and activities of the reporter gene were investigated too. The activity of the candidate promoter was investigated by loading F9 gene. RESULTS: The most potential RPS6 promoter was obtained by screening. There was no difference in lentiviral packaging between EF1 α-LV and RPS6-LV, and their virus titer were consistent. In 293T cells, the transduction efficiency and mean fluorescence intensity of RPS6pro-LV and EF1 αpro-LV were proportional to the lentiviral dose. The transfection efficiency of both promoters in different types of cells was in the following order: 293T>HEL>MSC; Compared with EF1 αpro-LV, RPS6pro-LV could obtain a higher fluorescence intensity in MSC cells, and RPS6pro-LV was more stable in long-term cultured HEL cells infected with two lentiviruses respectively. The results of RT-qPCR, Western blot and FIX activity (FIX∶C) detection of K562 cell culture supernatant showed that FIX expression in the EF1 α-F9 and RPS6-F9 groups was higher than that in the unloaded control group, and there was no significant difference in FIX expression between the EF1 α-F9 and RPS6-F9 groups. CONCLUSION: After screening and optimization, a promoter was obtained, which can be widely used for exogenous gene expression. The high stability and viability of the promoter were confirmed by long-term culture and active gene expression, which providing a powerful tool for basic research and clinical gene therapy of hemophilia.

[Clinical Analysis of Hospitalized Children with Primary Immune Thrombocytopenia].

OBJECTIVE: To investigate the factors affecting the chronicity of childhood primary immune thrombo-cytopenia (ITP) and compare the efficiency of different first-line treatment regimens. METHODS: Children with ITP hospitalized in our hospital from September 2013 to October 2018 were retrospectively analyzed. RESULTS: Three hundred and one children (150 males and 151 females) were included in this study, with a median age of 8 (0.17-17) years old, and 110 (36.5%), 92 (30.6%), and 99 (32.9%) cases were grouped into newly diagnosed, persistent, and chronic ITP, respectively. The median of follow-up was 41.92 (1.07-74.03) months. At the end of the follow-up (October 2019), among the 202 newly diagnosed/persistent ITP children, 79 cases (59 newly diagnosed and 20 persistent ITP) achieved remission within 1 year after initial diagnosis, with a remission rate of 39.3%; 122 cases (50 newly diagnosed and 72 persistent ITP) developed chronic disease, with a chronicity rate of 60.7%; one case underwent splenectomy. In 99 cases with chronic ITP, 5 cases underwent splenectomy. Multivariable logistic regression analysis showed that, the insidious onset of symptoms (OR=3.754, 95%CI: 1.882-7.488, P=0.000) increased the risk of chronicity, while the positive antibody to anti-platelet membrane glycoprotein (OR=0.446, 95%CI: 0.224-0.888, P=0.021) might reduce the risk of chronicity. And no difference was found by the analysis of subtype of anti-platelet membrane glycoprotein (P=0.305). The efficacy of the first-line treatment of intravenous immunoglobulin (IVIG) alone or combined with steroid was better than that of steroid alone (P=0.028, 0.028), however, the efficiency was not significantly different between IVIG alone and combined with steroid (P=0.086). CONCLUSION: Insidious onset of symptoms in pediatric ITP increases the risk of chronicity, while the positive titer of anti-platelet membrane glycoprotein may reduce the risk. In the first-line treatment for the newly diagnosed/persistent children. The efficacy of IVIG alone or combined with steroid is better than that of steroid alone.

[Symptomatic Profiles of 173 Chinese Patients with Essential Thrombocythemia].

OBJECTIVE: To explore the symptomatic burden of patients with essential thrombocythemia (ET) and its relation with clinical characteristics including the mutation status, therapeutic protocols and sex. METHODS: Total of 173 Chinese ET patients were selected and grouped on the basis of disease characteristics (mutation status, therapeutic pro to- cols, and sex). RESULTS: All the groups showed low-to-high symptom burden, with the highest in the Hu (hydroxyurea)-group (total symptom score [TSS], 14.7; range, 7.6-14.7). In the JAK2V617F-positive, Hu-treated, and female groups TSS and independent symptom scores were higher than those in the control group. The CALR-positive and IFN-α-treated groups had lower overall and individual scores as compared with groups lacking the corresponding characteristics. As the number of characteristics (JAK2V617F-positive, Hu-treated, and female) increases, the severity of symptoms gradually increased. CONCLUSION: The different characteristics have various effects on symptom burden in ET patients. The accumulation of certain characteristics will lead to more severe symptom burden, thus the patient＇s symptom burden should be considered comprehensively when making up the treatment schemes and prognosis.

[Clinical Characteristic of "triple-negative" Essential Thrombocythaemia Patients and Mutation Analysis by Targeted Sequencing].

BACKGROUND: Essential thrombocythemia is a subgroup of myeloproliferative neoplasms. Previous studies identified mutations of JAK2, CALR, and MPL that are closely related with the pathogenesis of myeloproliferative neoplasms. All these mutations contribute to the hyperactivation of JAK2/STAT pathway. However, a small proportion of essential thrombocythemia patients does not display such mutations. The pathogenesis of "triple-negative" form of essential thrombocythemia remains unknown. OBJECTIVE: To investigate the clinical characteristics of triple-negative essential thrombocythemia and related mutation genes. METHODS: To identify the mutations associated with triple-negative essential thrombocythemia, next-generation sequencing was used to conduct targeted sequencing of 360 genes in samples from 68 patients. RESULTS: At least one missense mutation was detected in all the patients and all the detected genes. After screening the data, it was observed that 10 genes with the 10 highest mutation were follows: FLT3, SH2B3, ASXL1, ADAMTS1, TET2, TP53, EGFR, CUX1, GATA2, and MPL.When only rare genes (i.e., with a frequency in Asian populations lower than 5%, as estimated by the 1000 Genomes Project) were analyzed, the most frequently mutated genes in the patients were TET2 (33.82%), SH2B3(29.41%), and ASXL1 (23.53%). Our study identified some mutations that did not previously reported. Although all these mutations need further validation, high incidence rates may indicate relevance of the respective mutations to essential thrombocythemia pathogenesis. Some of the detected mutations have been previously reported; these mutations were also found in a large proportion of our subjects. CONCLUSION: whole-exon sequencing can provide a higher level of accuracy for gene mutation analysis and assist in identifying mutations that contribute to illustrate the pathogenesis of essential thrombocythemia.

Chinese guidelines for treatment of adult primary immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is a bleeding disorder commonly encountered in clinical practice. The International Working Group (IWG) on ITP has published several landmark papers on terminology, definitions, outcome criteria, bleeding assessment, diagnosis, and management of ITP. The Chinese consensus reports for diagnosis and management of adult ITP have been updated to the 4th edition. Based on current consensus positions and new emerging clinical evidence, the thrombosis and hemostasis group of the Chinese Society of Hematology issued Chinese guidelines for management of adult ITP, which aim to provide evidence-based recommendations for clinical decision making.

[Clinical Characteristics and Long-Term Outcome of 125 Chinese Young Patients with Essential Thrombocythemia].

OBJECTIVE: To investigate the clinical characteristics and long-term outcome of Chinese young patients (≤40 years) with essential thrombocythemia(ET), and to develop a thrombosis predicting model specific for young patients with ET, so as to provide a new evidence for risk stratification and treatment. METHODS: Medical records of 125 Chinese young patients with newly diagnosed of ET were retrospectively analyzed. RESULTS: The median age at diagnosis was 32 (18-40) years old, with 37 males and 88 females. During follow-up, 18 patients (14.4%) experienced major thrombotic events. JAK2 V617F (HR=8.895, P=0.001), history of thrombosis (HR=8.001, P<0.001) and WBC≥12.0×109/L (HR=5.225, P=0.002) were independent risk factors for thrombosis. The incidence of thrombosis and risk factors in young patients were different from that in general ET population, so a thrombosis predicting model specific for young patients with ET was developed. In this model, JAK2 V617F (score 2), history of thrombosis (score 2) and WBC≥12.0×109/L (score 1) were used to divide the patients into low risk (score 0), intermediate risk (score 1-2) and high risk (score≥3) groups. These 3 groups exhibited significantly different thrombosis-free survival (χ2=32.223, P<0.001). Antiplatelet treatment could prevent the occurrence of thrombosis (HR=0.081, P<0.001), while cytoreductive agents significantly decreased the risk of thrombosis only in intermediate and high risk groups (14.3% vs 36.4%, χ2=4.416, P=0.036). Seven patients (5.6%) evolved to myelofibrosis, and one of them finally progressed in to acute leukemia. The only risk factor for evolution was WBC≥15.0×109/L (χ2=5.434, P=0.020). Neither antiplatelet treatment nor cytoreductive agents could prevent disease progression. CONCLUSION: The incidence of thrombosis and risk factors in young patients with ET are different from that in general ET population. The thrombosis-predicting model specific for young patients with ET is useful for guiding therapeutic decisions.

Interleukin-7 is decreased and maybe plays a pro-inflammatory function in primary immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is an autoimmune disease with many immune dysfunctions, including over-proliferation and apoptosis resistance of auto-reactive lymphocytes. This study aimed to determine the effects of interleukin (IL)-7 on the cytokine production and survival of peripheral blood mononuclear cells and bone marrow mononuclear cells from ITP patients. We found that the plasma IL-7 levels in peripheral blood from ITP patients were lower than that of the normal controls, and it had positive correlation with platelet counts. However, the levels of IL-7 did not change in bone marrow serum of ITP patients compared with that of normal controls. The result of further stimulation experiments in vitro showed that IL-7 up-regulated the apoptosis of autologous platelets, promoted the proliferation and secretion of interferon-γ, tumor necrosis factor-α as well as IL-10 of lymphocyte both from peripheral blood and bone marrow. As the role of IL-7 in apoptosis-resistance and stimulation of pro-inflammatory cytokines, we speculated that decreased IL-7 in peripheral blood, maybe, is a consequence of the negative feedback of the pro-inflammatory function in ITP patients.

[Role of Toll-like receptor 2 in primary immune thrombocytopenia].

The aim of this study was to explore the role of Toll-like receptor (TLR) 2 in primary immune thrombocytopenia (ITP) by detecting TLR2 expression in the peripheral blood lymphocytes of patients with ITP and evaluating the role of TLR2 activation on inflammatory cytokine secretion. A total of 39 ITP patients and 21 normal controls were enrolled in this study. The expression of TLR2 was detected by real-time PCR and flow cytometry, and the concentration of IL-6 and TNF-α in culture supernatant of PBMNC treated with pam3CSK4 for 48 hours were detected by ELISA. The results showed that the expression of TLR2 mRNA in active ITP patients (3.561 ± 0.741) was significantly higher than that in normal controls (1.750 ± 0.314) (P < 0.05), but there was no statistically significant difference between remission ITP patients (2.333 ± 0.448) and normal controls (P > 0.05) . Flow cytometry analysis found that the TLR2 was not expressed on T and B cells, but expressed on all monocytes both from ITP patients and normal controls. Further activation experiment showed that TLR2 activation in vitro could induce the expression of IL-6 (1644 ± 634.0 vs 4111 ± 525.2 pg/ml) and TNF-α (75.37 ± 22.31 vs 326.0 ± 109.9 pg/ml) in PBMNC from ITP patients (both P < 0.05), but just could promote IL-6 expression in normal controls (2119 ± 636.9 vs 4671 ± 315.9 pg/ml)(P < 0.05). It is concluded that the expression of TLR2 mRNA is up-regulated in PBMNC of ITP patients, and this increased TLR2 maybe participate in ITP through inducing secretion of inflammatory cytokines.

[Clinical characteristics of 520 children with hemophilia in a single medical center].

OBJECTIVE: To analyze the clinical characteristics, diagnosis and treatment of pediatric hemophilia in single center over the decade. METHODS: A retrospective study was conducted with 520 hemophilic children hospitalized in our medical center between January 2002 and December 2012. RESULTS: All the patients were male including 438 hemophilia A (HA) and 82 hemophilia B (HB). There were significant differences in APTT between severe and mild- to moderate hemophilia (P<0.05). In pediatric HA and HB, delay time of diagnosis were 1.42 and 1.17 year, respectively. Children of 7-12 years were the largest population of visiting a doctor, and the spontaneous bleeding episode was the main cause. The most common hemorrhage site was soft tissue in early childhood, but joint was increasingly affected with age as children growth. All bleeding sites and frequencies were not associated with plasma factor level of patient (P>0.05). Knee and anKle were mainly involved in early child, while elbow and shoulder were involved increasingly in later childhood. Additionally, in HA and HB, inhibitor occurrence were 8.9%(19/214) and 12.8%(5/39), inducing 78.9%(15/19) and 40.0%(2/5) of high titer inhalator, and antiHCV-positive rate were 2.8%(11/397) and 2.5%(2/79), respectively. CONCLUSION: Our data highlights that delay in diagnosis and blood-borne infections were significantly reduced over the decade, but the development of inhibitor still remains a major challenge with wide-scale usage of factor in replacement therapy.

[Relationship between the expression of autoantibodies against platelet membrane glycoprotein and therapeutic effect in primary immune thrombocytopenia].

OBJECTIVE: To study the expression of specific anti- platelet glycoprotein autoantibodies GP II b/III a, GP I b/IX and GP I a/II a in primary immune thrombocytopenia (ITP), and to evaluate the relationship between the therapeutic effect and the expression of specific anti- platelet glycoprotein antibodies GPIIb/IIIa, GPIb/IX and GPIa/IIa. METHODS: Anti-GPIIb/IIIa, GPIb/ IX and GP I a/II a antibodies were assayed by ELISA for patients with ITP. Total 442 patients in our hospital, who were retrospectively investigated from December 2010 to November 2012, were divided into newly diagnosed ITP, persistent and chronic ITP. The expression of specific anti- platelet glycoprotein antibody in each group was measured separately. The newly diagnosed ITP patients were treated with intravenous IgG (IVIG) and corticosteroids. The relationship between the expression of specific anti- platelet glycoprotein antibodies GPIIb/IIIa, GPIb/IX and GPIa/IIa and the complete response (CR) was studied. RESULTS: Positive rates of anti- platelet glycoprotein antibodies were 59.09%, 26.97% and 37.35% respectively in newly diagnosed ITP, persistent and chronic ITP, the difference was statistical significant (P<0.05). In newly diagnosed ITP, positive rate of antibody against GPIIb/IIIa was 38.64%, double positive rate of antibodies against both GP II b/III a and GP I a/II a was 15.91%, there was statistical significance (P<0.05) compared with that of persistent and chronic ITP. The complete response (CR) rate in newly diagnosed ITP patients with positive antibody against GP II b/III a was 80.39% after treatment with IVIG and corticosteroids. There was statistical significance compared with that in patients having no antibodies (P<0.05). CONCLUSION: The expression of antibodies against GP II b/III a and double positive for both GP II b/III a and GP I a/II a autoantibodies increased in newly diagnosed ITP patients. Patients with anti-GP II b/III a autoantibody had good response to medication with IVIG and corticosteroids.

[A novel diagnostic measure of platelet-specific antibody in immune thrombocytopenia].

OBJECTIVE: To detect the platelet glycoprotein-specific antibodies in serum of thrombocytopenia patients and evaluate its diagnostic value for immune thrombocytopenia. METHOD: Anti-GPIIb/IIIa, GPIb/IX and GPIa/IIa antibodies were assayed by ELISA kit (PAKUTO) in patients with thrombocytopenia. RESULTS: The sensitivity and specificity of PAKAUTO in immune thrombocytopenia were 44.0% and 95.7%, respectively. The values of positive and negative predictions were 98.0% and 26.2%, respectively. Among those PAKAUTO positive patients, positive rates of GPIIb/IIIa, GPIa/IIa and GPIb/IX were 87%, 35% and 10%, respectively. The positive rate of patients not received immune suppressive agents (58.5%) was significantly higher than those received immune suppressive agents (26.9%) (P < 0.01). The positive rate of patients with platelet count ≤ 20 × 10(9)/L (51.6%) was significantly higher than those with platelet count > 20 × 10(9)/L (27.8%) (P < 0.01). The positive rate of patients with secondary immune thrombocytopenia (66.7%) was significantly higher than those with primary immune thrombocytopenia (41.7%) (P < 0.05). CONCLUSION: The highly specific method (PAKAUTO) could effectively differentiate immune or non-immune thrombocytopenia and be applied to diagnosis of immune thrombocytopenia.

[Acquired factor V inhibitor: 3 cases report and literature review].

OBJECTIVE: To better understand the acquired factor V (FV) inhibitors. METHODS: The clinical features, laboratory manifestations, treatment options and prognosis of 3 cases were reported and related literature were reviewed. RESULTS: All the 3 patients were older than 50 years without family history and related disease. Their clinical manifestations included spontaneously mucous bleeding, hematuria, epistaxis and encephalic bleeding. Laboratory test showed prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT). The FV levels decreased and the presence of FV inhibitor was confirmed by Bethesda method. All patients were treated with glucocorticoid and immunosuppressive agents. The haemorrhages of two patients stopped but their coagulation test and FV level recovered slowly. One patient died from encephalic bleeding. CONCLUSIONS: Acquired FV inhibitor is a rare coagulation disorder with variable clinical symptoms. Immunosuppressive agents are effective to eliminate the inhibitors. The prognosis of acquired FV inhibitors seemed to be strictly related to the basic disease.

[The activity levels and prevalence of deficiency of protein C, protein S and antithrombin in Chinese Han population].

OBJECTIVE: To explore the distribution and influence factors of protein C (PC), protein S (PS) and antithrombin (AT) activities and to determine the prevalence of their deficiencies in the Chinese Han healthy population. METHODS: Healthy volunteers including blood donors and individuals for routine check-up were recruited from 4 Chinese medical centers. The plasma levels of PC, PS and AT activities were measured. The plasma levels of activities were measured by chromogenic substrate assay (AT and PC) and clotting assay (PS). RESULTS: A total of 3493 healthy Chinese adults had been recruited in this study. Males had higher PS and PC activities than females, especially for PS (P < 0.01). PC activities increased with age in both sexes but decreased in men after 50 years old. There was no significant change with age were of PS in 50 years old, while there was a decline in males and a rise in females above 50 years old. AT tended to increase with age in women but decreased with age in men after 50 years old. Based on the age and gender, the general prevalence of PC, PS and AT deficiencies in the general Chinese Han population were 1.15%, 1.49% and 2.29%, respectively. CONCLUSION: PC, PS and AT activities have correlation with age and gender in Chinese Han population. Reference range should be laid down and deficiencies should be identified

[Effect of mesenchymal stem cells on human Th1 cells by flow cytometry].

This study was aimed to investigate the effect of fetal bone marrow-derived mesenchymal stem cells (FBM-MSC) on the development of human Th1 cells. FBM-MSC were isolated, cultured and expanded in vitro. The cells were identified by their phenotype profiles and differential capacity. Human CD4(+) T cells from healthy donors were cultured alone or co-cultured with FBM-MSC (FBM-MSC/CD4). In these two cultures, the quantities of Th1 cells (interferon-γ(+)) were analyzed by flow cytometry. The results indicated that the immunophenotype and multilineage differentiation of FBM-MSC satisfied the generally accepted criteria. FBM-MSC played an inhibitory role in the development of Th1 cells. Flow cytometry analysis showed that the percentage of Th1 cells in FBM-MSC/CD4 was significantly lower than that in CD4(+) T cells cultured alone. The protein level of IFN-γ in FBM-MSC/CD4 detected by ELISA was also lower than that in CD4(+) T cells cultured alone. It was also demonstrated that the expression level of IL-6 in FBM-MSC/CD4 was much higher than that in CD4(+) T cells cultured alone or FBM-MSC. The neutralizing antibody of IL-6 could increase the quantities of Th1 cells and the expression levels of IFN-γ. It is concluded that FBM-MSC may play an inhibitory role in the development of human Th1 cells, and the IL-6 pathway may be one of mechanisms involved in the inhibitory role.

Elevated interleukin-27 enhances the polarization of Th1/Tc1 cells and the production of proinflammatory cytokines in primary immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is an acquired, organ-specific, autoimmune disease with many immune dysfunctions. Interleukin-27 (IL-27) can regulate T cell differentiation. However, it is unclear whether IL-27 correlates with the dysfunctions of T cell differentiation in ITP patients. Thus, to determine the roles of IL-27 in ITP, we studied the expression of IL-27/IL-27 receptor in ITP patients. The results indicated that the levels of IL-27 in the plasma of untreated active ITP patients were higher than in normal controls. We next evaluated the contribution of IL-27 to T cell differentiation. Our results indicated that IL-27 increased T-bet expression, inhibited GATA-3 and ROR-γt expression, and promoted the secretion of tumor necrosis factor-α, interferon-γ, and granzyme B of peripheral blood mononuclear cells from ITP patients. Also, we confirmed that IL-27 induced the differentiation of T helper (Th)-1 and Tc1 cells. In conclusion, IL-27 might play an important role in the pathogenesis of ITP by inducing the polarization of Th1/Tc1 cells and the production of proinflammatory cytokines.

CD72 gene expression in immune thrombocytopenia.

To explore the role of CD72 in the pathogenesis of immune thrombocytopenia (ITP), we detected CD72, Sema4D, IL-2, IL-4, and IFN-γ mRNA expressions and the levels of plasma Sema4D, IL-2, IL-4, IL-6, and IFN-γ in ITP patients (n = 39) and controls (n = 23). The levels of plasma IL-2, IL-4, and IL-6 were assayed by radioimmunoassay, and the levels of plasma IFN-γ and Sema4D were analyzed by enzyme-linked immunosorbent assay. Sema4D, CD72, IL-2, IFN-γ, and IL-4mRNA expressions were analyzed by real-time quantitative reverse-transcription polymerase chain reaction. The expression of CD72 mRNA in ITP patients (n = 23) with active disease was significantly lower than that in patients in remission (p = 0.029) (n = 16) and controls (p = 0.0296) (n = 23). The IFN-γ/IL-4 mRNA (Th1/Th2) expression in ITP patients with active disease and in remission was significantly higher than that in controls (p = 0.0023, p = 0.0125, respectively). The expression of IL-2 mRNA in ITP patients with active disease was significantly lower than that in patients in remission (p = 0.0418) and controls (p = 0.004). The level of plasma IL-2 in ITP patients with active disease was significantly lower than that in patients in remission (p = 0.0029) and controls (p = 0.0101). The levels of plasma IL-4 in ITP patients with active disease and in remission were significantly higher than that of controls (p = 0.0093, p = 0.0053, respectively). CD72 mRNA expression level might correlate with Sema4D mRNA expression in peripheral blood mononuclear cells and level of plasma IL-2 in active ITP patients (p = 0.024 and p = 0.036). Our findings suggest that CD72 might be involved in the pathophysiological process of the ITP disease by increasing B-cell receptor signals.