Essential role of glycoprotein Ibα in platelet activation

Glycoprotein (GP) Ib, the ligand-binding subunit of platelet GPIb-IX complex, interacts with von Willebrand factor (VWF) exposed at the injured vessel wall, initiating platelet adhesion, activation, hemostasis, and thrombus formation. The cytoplasmic tail of GPIb interacts with 14-3-3, regulate ng the VWF-GPIb-elicited signal transduction and VWF binding function of GPIb. However, we unexpectedly found that the GPIb-14-3-3 association, beyond VWF-dependent function, is essential for general platelet activation. We found that the GPIb cytoplasmic tail peptide MPC, a potential GPIb inhibitor, by itself induced platelet aggregation, integrin αIIbβ3 activation, granule secretion, and phosphatidylserine (PS) exposure. Conversely, the deletion of the cytoplasmic tail of GPIb in mouse platelets (10aa-/-) decreased platelet aggregation, integrin IIb3 activation, granule secretion, and PS exposure induced by various physiological agonists. Phosphoproteome-based kinase activity profiling revealed significantly upregulated protein kinase C (PKC) activity in MPC-treated platelets. MPC-induced platelet activation was abolished by the pan-PKC inhibitor and PKC deletion. Decreased PKC activity was observed in both resting and agonist-stimulated 10aa-/- platelets. GPIb regulates PKC activity by sequestering 14-3-3 from PKC. In vivo, the deletion of the GPIb cytoplasmic tail impaired mouse hemostasis and thrombus formation and protected against platelet-dependent pulmonary thromboembolism. Therefore, our findings demonstrate an essential role for the GPIb cytoplasmic tail in regulating platelet general activation and thrombus formation beyond the VWF-GPIb axis.

Novel GNE missense variants impair de novo sialylation and cause defective angiogenesis in the developing brain in mice

ABSTRACT

Glucosamine (UDP-N-acetyl)-2-epimerase and N-acetylmannosamine (ManNAc) kinase (GNE) is a cytosolic enzyme in de novo sialic acid biosynthesis. Congenital deficiency of GNE causes an autosomal recessive genetic disorder associated with hereditary inclusion body myopathy and macrothrombocytopenia. Here, we report a pediatric patient with severe macrothrombocytopenia carrying 2 novel GNE missense variants, c.1781G>A (p.Cys594Tyr, hereafter, C594Y) and c.2204C>G (p.Pro735Arg, hereafter, P735R). To investigate the biological significance of these variants in vivo, we generated a mouse model carrying the P735R mutation. Mice with homozygous P735R mutations exhibited cerebral hemorrhages as early as embryonic day 11 (E11), which subsequently progressed to large hemorrhages in the brain and spinal cord, and died between E11.5 and E12.5. Defective angiogenesis such as distended vascular sprouts were found in neural tissues and embryonic megakaryocytes were abnormally accumulated in the perineural vascular plexus in mutant mouse embryos. Furthermore, our in vitro experiments indicated that both C594Y and P735R are loss-of-function mutations with respect to de novo sialic acid biosynthesis. Overall, this study reveals a novel role for GNE-mediated de novo sialic acid biosynthesis in mouse embryonic angiogenesis.

Mutation detection and inhibitor analysis of 43 children with severe hemophilia A in a single center: three novel mutations

To investigate the risk factors of FVIII inhibitors development in severe hemophilia A (HA) patients who were received on-demand therapy and were infused with plasma cryoprecipitate and multiple FVIII concentrates alternately. We collected clinical information from 43 severe HA children who were treated with plasma cryoprecipitate and multiple FVIII concentrates. The F8 mutation was detected by long-distance PCR for inversion and detected by all exons and their flanking sequencing for other mutations. The inhibitor detection was performed by Nijmegen-modified Bethesda assay. The impact of novel amino substitutions on FVIII protein was predicted by SIFT and PolyPhen-2. The 3D analysis of missense mutations was performed using Swiss-PdbViewer. FVIII inhibitors were detected in nine cases (20.9%). All of the inhibitor positive cases had high risk F8 gene mutations. In most of the positive cases (7/9), inhibitors were developed during the first 10 EDs, which was significantly higher than that in the 10-50 EDs group and 50 EDs group (p = 0.009). Three novel mutations were reported, including c.214G > T (E72X), c.218 T > C (F73S), and c.2690C > G (S840X). For severe HA patients who are treated with multiple products of replacement therapy, it is important to supervise inhibitor during the first 10EDs, especially for those with high risk F8 gene mutations. F8 gene mutation is one of the most important genetic factors for inhibitor development. It is essential to detect F8 gene for all severe HA patients. Three novel mutations were reported to expand the mutation spectrum of the F8 gene.

Cyclic thrombocytopenia associated with estradiol: a case report

OBJECTIVES

Cyclic thrombocytopenia (CTP) is a rare blood disorder characterized by periodic fluctuations in platelet counts. CTP usually appears in pre-menopausal women, and these fluctuations of platelets are in phase with the menstrual cycle. CTP is a heterogeneous disease, and the pathogenic mechanism is still unclear. Therefore, it harbors great significance for exploring the association of fluctuations in platelet counts with hormonal-cycle.

MATERIALS

Firstly, we washed human platelets from healthy volunteers following the Declaration of Helsinki. Flow cytometer was employed to measure the mitochondrial inner transmembrane potential (ΔΨm) depolarization, PS exposure, P-selectin expression, and GPIIb/IIIa activation in platelets. In addition, western blot detected the related protein expression. The corresponding assay kit measured the caspase-3 and PDE3A activity. Finally, flow cytometry determined mouse platelets labeled with calcein.

RESULTS

We find a reverse relationship between the platelet count and serum estradiol (E2) level in a CTP patient. We demonstrated that E2 induces platelet apoptosis in vitro and platelet clearance in vivo. We further discovered that E2 activates phosphodiesterase 3A, which inhibits protein kinase A (PKA), leading to PKA-mediated platelet apoptosis. Activation of PKA protected platelets from E2-induced thrombocytopenia and elevated the number of mice circulatory platelets.

CONCLUSIONS

We find that E2 induces platelet apoptosis and clearance through PDE3A-mediated PKA inhibition. Activation of PKA rescues E2-induced thrombocytopenia in mice. Thus, our study reveals a pathogenesis of E2-related CTP and suggests promising therapeutic strategies for the disease.

A conserved ZFX/WNT3 axis modulates the growth and imatinib response of chronic myeloid leukemia stem/progenitor cells

BACKGROUND

Zinc finger protein X-linked (ZFX) has been shown to promote the growth of tumor cells, including leukemic cells. However, the role of ZFX in the growth and drug response of chronic myeloid leukemia (CML) stem/progenitor cells remains unclear.

METHODS

Real-time quantitative PCR (RT-qPCR) and immunofluorescence were used to analyze the expression of ZFX and WNT3 in CML CD34+ cells compared with normal control cells. Short hairpin RNAs (shRNAs) and clustered regularly interspaced short palindromic repeats/dead CRISPR-associated protein 9 (CRISPR/dCas9) technologies were used to study the role of ZFX in growth and drug response of CML cells. Microarray data were generated to compare ZFX-silenced CML CD34+ cells with their controls. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays were performed to study the molecular mechanisms of ZFX to regulate WNT3 expression. RT-qPCR and western blotting were used to study the effect of ZFX on β-catenin signaling.

RESULTS

We showed that ZFX expression was significantly higher in CML CD34+ cells than in control cells. Overexpression and gene silencing experiments indicated that ZFX promoted the in vitro growth of CML cells, conferred imatinib mesylate (IM) resistance to these cells, and enhanced BCR/ABL-induced malignant transformation. Microarray data and subsequent validation revealed that WNT3 transcription was conservatively regulated by ZFX. WNT3 was highly expressed in CML CD34+ cells, and WNT3 regulated the growth and IM response of these cells similarly to ZFX. Moreover, WNT3 overexpression partially rescued ZFX silencing-induced growth inhibition and IM hypersensitivity. ZFX silencing decreased WNT3/β-catenin signaling, including c-MYC and CCND1 expression.

CONCLUSION

The present study identified a novel ZFX/WNT3 axis that modulates the growth and IM response of CML stem/progenitor cells.

[Analysis of clinical phenotype and gene mutation characteristics of MYH9-related disorder]

Objective: To investigate the clinical phenotype and gene mutation characteristics of MYH9-related disorder (MYH9-RD). Methods: The clinical data of 66 patients with MYH9-RD in the First Affiliated Hospital of Soochow University from January 2010 to December 2022 were retrospectively analyzed. According to the bleeding symptom, the patients were divided into bleeding and non-bleeding group, and according to the mutation sites, the patients were divided into non-muscle myosin heavy chain ⅡA head region (MD) and tail region (TD) mutation group. Statistical analysis was made to explore the clinical features in different groups such as platelet counts, bleeding, renal function, cataracts and hearing as well as MYH9 gene mutations. Results: A total of 66 MYH9-RD patients were included, with 28 males and 38 females, diagnosis age of 1-63(26±2) years. And 41% (27/66) of the patients had no family history. All patients presented with macrothrombocytopenia and normal platelet aggregation(10/10), 92% (54/59) of the patients had visible blue inclusion bodies in neutrophils, 30% (20/66) had bleeding symptoms, 45% (22/49) had proteinuria or glomerulonephropathy, 20% (8/41) had bilateral hearing impairment, and 10% (4/42) had bilateral cataracts. 18 mutation sites were identified in total, including 15 missense, 1 splicing and 2 termination mutations. Among them, p.Asp1424Asn, p.Arg1933* and p.Arg702His/Cys mutations were identified in 56% (29/52) of the patients, and p.Ser96Leu, Arg1165Cys and p.Glu1841Lys mutations were recurrent mutations, while p.Ala44Thr, p.Asp1447Ala and c.3838-2A>G mutations were novel mutations. The average platelet count of patients in bleeding group was (19±3)×109/L, which was significantly less than (36±3)×109/L in non-bleeding group (P<0.001). Compared with TD mutation group, patients of MD mutation group were presented with lower platelet count and higher risk of bleeding, as well as more severe clinical presentations including renal and hearing impairment and cataracts (all P<0.05). Conclusion: Mutations of p.Asp1424Asn, p.Arg1933* and p.Arg702His/Cys in MYH9 gene are hotspot mutations for MYH9-RD patients, Compared with TD mutation group, patients of MD mutation group were presented with lower platelet count and higher risk of bleeding, as well as more severe clinical presentations including renal and hearing impairment and cataracts.

Safety and efficacy of an anti-human APC antibody for prophylaxis of congenital factor deficiencies in preclinical models

Rebalance of coagulation and anticoagulation to achieve a hemostatic effect has recently gained attention as an alternative therapeutic strategy for hemophilia. We engineered a humanized chimeric antibody, SR604, based on a previously published murine antibody, HAPC1573, which selectively blocks the anticoagulant activity of human activated protein C (APC). SR604 effectively blocked the anticoagulation activities of APC in human plasma deficient in various coagulation factors in vitro with affinities ∼60 times greater than that of HAPC1573. SR604 exhibited prophylactic and therapeutic efficacy in the tail-bleeding and knee-injury models of hemophilia A and B mice expressing human APC (humanized hemophilic mice). SR604 did not interfere with the cytoprotection and endothelial barrier function of APC, nor were there obvious toxicity effects in humanized hemophilic mice. Pharmacokinetic study showed a high bioavailability (106%) of subcutaneously injected SR604 in cynomolgus monkeys. These results demonstrate that SR604 is expected to be a safe and effective therapeutic and/or prophylactic agent with a prolonged half-life for patients with congenital factor deficiencies including hemophilia A and B.

Insights from a rare myeloproliferative neoplasm with coexisting BCR-ABL1 fusion gene, CALR, and TET2 mutations treated with nilotinib and ruxolitinib

Myeloproliferative neoplasms (MPNs) with concurrent BCR-ABL1 fusion gene and CALR mutation are especially rare. We report a patient with coexisting BCR-ABL1 fusion gene, CALR, and TET2 mutations who was treated with the combination of the second-generation TKI nilotinib and JAK1/JAK2 inhibitor ruxolitinib.

[Clinical diagnosis and treatment of hereditary thrombocytopenia and purpura: a report of five cases and literature review]

Objective: To report the clinical manifestations and laboratory features of five patients with congenital thrombotic thrombocytopenic purpura (cTTP) and explore its standardized clinical diagnosis and treatment along with a review of literature. Methods: Clinical data of patients, such as age of onset, disease manifestation, personal history, family history, and misdiagnosed disease, were collected. Treatment outcomes, therapeutic effects of plasma infusion, and organ function evaluation were observed. The relationship among the clinical manifestations, treatment outcomes, and ADAMTS13 gene mutation of patients with cTTP was analyzed. Additionally, detection of ADAMTS13 activity and analysis of ADAMTS13 gene mutation were explored. Results: The age of onset of cTTP was either in childhood or adulthood except in one case, which was at the age of 1. The primary manifestations were obvious thrombocytopenia, anemia, and different degrees of nervous system involvement. Most of the patients were initially suspected of having immune thrombocytopenia. Acute cTTP was induced by pregnancy and infection in two and one case, respectively. ADAMTS13 gene mutation was detected in all cases, and there was an inherent relationship between the mutation site, clinical manifestations, and degree of organ injury. Therapeutic or prophylactic plasma transfusion was effective for treating cTTP. Conclusions: The clinical manifestations of cTTP vary among individuals, resulting in frequent misdiagnosis that delays treatment. ADAMTS13 activity detection in plasma and ADAMTS13 gene mutation analysis are important bases to diagnose cTTP. Prophylactic plasma transfusion is vital to prevent the onset of the disease.

Appropriate pre-transplant strategy for patients with myelodysplastic syndromes receiving allogeneic haematopoietic stem cell transplantation after myeloablative conditioning

Purpose

Appropriate pre-transplant strategies in patients with myelodysplastic syndromes (MDS) remain challenging. We sought to assess the effect of different pre-transplant therapies and transplantation interval times on patient prognosis.

Methods

We retrospectively analysed clinical data for 371 consecutive MDS patients after myeloablative transplantation between 2007 and 2019.

Results

The median age of the patients was 38 years (range, 12-64 years). A total of 114 patients (31%) received supportive care (SC), 108 (29%) hypomethylating agents (HMAs), and 149 (40%) chemotherapy-based therapy before transplantation. In patients who received HMA or SC, there was no significant difference in overall survival (OS; P=0.151) or relapse-free survival (RFS; P=0.330), except that HMA-treated patients had a lower rate of non-relapse mortality (5-year NRM: 18% vs. 32%, P=0.035). However, compared with patients who received HMA, those who received chemotherapy-based therapy had a lower 5-year OS rate (56% vs. 69%, P=0.020) and a slightly higher 5-year NRM rate (28% vs. 18%, P=0.067). Compared to the delayed transplant group (transplant interval ≥6 months), the early transplant group (transplant interval <6 months) had a superior 5-year OS (66% vs. 51%, P=0.001) and a lower 5-year cumulative incidence of NRM (22% vs. 36%, P=0.001).

Conclusion

The findings of the study indicate that receiving an appropriate pre-transplant strategy (SC/HMA + <6 months) significantly improves OS and decreases NRM in MDS patients after myeloablative transplantation.

Upregulation of HIF-1α contributes to complement activation in transplantation-associated thrombotic microangiopathy

Transplantation-associated thrombotic microangiopathy (TA-TMA) is a severe complication of haematopoietic stem cell transplantation (HSCT). Complement activation is involved in the development of TA-TMA. However, the underlying mechanism is unclear. Therefore, 21 samples of TA-TMA and 1:1 matched controls were measured for hypoxia-inducible factor-1α (HIF-1α) and complement protein. The mechanism was investigated both in vitro and in vivo. In this study, we found that levels of HIF-1α were significantly higher in TA-TMA patients than that in non-TA-TMA controls. Upregulation of HIF-1α induced an increase in membrane-bound complement C3 and dysfunction of human umbilical vein endothelial cells (HUVECs) in vitro. Increasing HIF-1α in vivo led to C3 and C5b-9 deposition in the glomerular endothelial capillary complex, thrombocytopenia, anaemia, and increased serum lactate dehydrogenase (LDH) levels in wild-type (WT) but not in C3^-/- mice subjected to HSCT. High platelet aggregation in peripheral blood and CD41-positive microthrombi in the kidney were also found in dimethyloxallyl glycine (DMOG)-treated mice, recapitulating the TA-TMA phenotype seen in patients. Comprehensive analysis, including DNA array, luciferase reporter assay, chromatin immunoprecipitation (ChIP)-seq, and quantitative polymerase chain reaction (PCR), revealed that HIF-1α interacted with the promoter of complement factor H (CFH) to inhibit its transcription. Decreased CFH led to complement activation in endothelial cells.

Prognostic Value of Thrombocytopenia in Myelodysplastic Syndromes After Hematopoietic Stem Cell Transplantation

Prolonged isolated thrombocytopenia (PT) is a common complication affecting the outcome of stem cell transplantation. In this study, we undertook a real-world study of 303 myelodysplastic syndrome (MDS) patients who received allogeneic hematopoietic stem cell transplantation (HSCT) between December 2007 and June 2018. 28.4% of MDS patients suffered from PT after HSCT. Survival analysis indicated that PT was associated with worse overall survival (OS) in MDS patients. The 2-year and 5-year OS in MDS patients with PT after HSCT were 49% and 47%, significantly worse than that of 68% and 60% in patients without PT (P=0.005). For RFS, patients with PT did not have an increased risk of disease relapse (P=0.964). After multivariate adjustment, PT was proved to be the independent risk factor associated with the worse OS (HR 1.49, 95% CI 1.00-2.21, P =0.048). We further analyzed risk factors associated with the occurrence of PT in MDS patients. Multiple logistic regression identified grade II-IV aGVHD, extensive chronic GVHD, hemorrhagic cystitis, and CMV activation as significant risk factors for developing PT. Among these variables, the Odds Ratio (OR) of grade II-IV aGVHD was the highest (P =0.001, OR: 2.65, 95% CI: 1.51-4.64). These data indicated the prognostic value of PT in MDS after HSCT. The identification of risk factors for PT may help improve patient management and lead to the design of effective treatment strategies.

Effectiveness and safety of leukapheresis in hyperleukocytic leukemias: a retrospective multicenter study

Leukapheresis is an effective adjuvant therapy for leukemia patients with hyperleukocytosis, but few studies have reported recent data with modern modalities and comparisons among different leukemia types. We conducted a retrospective study on leukapheresis among 420 patients with AML, ALL and CML in four local centers. WBC counts decreased significantly (p < 0.001) postleukapheresis in all three cohorts. Clearance efficiency was higher in acute leukemia patients than CML patients (p < 0.01). Concomitant leukocytoreduction drugs improved WBC reduction only in AML patients (p < 0.05). Leukocyte, hemoglobin and platelet levels preleukapheresis might affect the clearance efficiency in AML and/or ALL patients. Hematological toxicities were the major concerns, but most of them were mild, and only 11 patients died of all causes within one week postleukapheresis. In conclusion, leukapheresis can safely reduce the leukemic burden, especially for patients with acute leukemias.

Plasma Metabolomics Identifies the Dysregulated Metabolic Profile of Primary Immune Thrombocytopenia (ITP) Based on GC-MS

ITP is a common autoimmune bleeding disorder with elusive pathogenesis. Our study was implemented to profile the plasma metabolic alterations of patients diagnosed with ITP, aiming at exploring the potential novel biomarkers and partial mechanism of ITP. The metabolomic analysis of plasma samples was conducted using GC-MS on 98 ITP patients and 30 healthy controls (HCs). Age and gender matched samples were selected to enter the training set or test set respectively. OPLS-DA, t-test with FDR correction and ROC analyses were employed to screen out and evaluate the differential metabolites. Possible pathways were enriched based on metabolomics pathway analysis (MetPA). A total of 85 metabolites were investigated in our study and 17 differential metabolites with diagnostic potential were identified between ITP patients and HCs. MetPA showed that the metabolic disorders of ITP patients were mainly related to phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism and glyoxylate and dicarboxylate metabolism. Additionally, we discriminated 6 differential metabolites and 5 enriched pathways in predicting the resistance to glucocorticoids in chronic ITP patients. The distinct metabolites discovered in our study could become novel biomarkers for the auxiliary diagnosis and prognosis prediction of ITP. Besides, the dysregulated pathways might contribute to the development of ITP.

Kupffer cell receptor CLEC4F is important for the destruction of desialylated platelets in mice

The liver has recently been identified as a major organ for destruction of desialylated platelets. However, the underlying mechanism remains unclear. Kupffer cells, which are professional phagocytic cells in the liver, comprise the largest population of resident tissue macrophages in the body. Kupffer cells express a C-type lectin receptor, CLEC4F, that recognizes desialylated glycans with an unclear in vivo role in mediating platelet destruction. In this study, we generated a CLEC4F-deficient mouse model (Clec4f^-/-) and found that CLEC4F was specifically expressed by Kupffer cells. Using the Clec4f^-/- mice and a newly generated platelet-specific reporter mouse line, we revealed a critical role for CLEC4F on Kupffer cells in mediating destruction of desialylated platelets in the liver in vivo. Platelet clearance experiments and ultrastructural analysis revealed that desialylated platelets were phagocytized predominantly by Kupffer cells in a CLEC4F-dependent manner in mice. Collectively, these findings identify CLEC4F as a Kupffer cell receptor important for the destruction of desialylated platelets induced by bacteria-derived neuraminidases, which provide new insights into the pathogenesis of thrombocytopenia in disease conditions such as sepsis.

Development of a Nomogram for Predicting the Cumulative Incidence of Disease Recurrence of AML After Allo-HSCT

Using targeted exome sequencing, we studied correlations between mutations at diagnosis and transplant outcomes in 332 subjects with acute myeloid leukemia (AML) receiving allotransplantation. A total of 299 patients (299/332, 90.1%) had at least one oncogenic point mutation. In multivariable analyses, pretransplant disease status, minimal residual disease (MRD) before transplantation (pre-MRD), cytogenetic risk classification, and TP53 and FLT3-ITD^{high ratio} mutations were independent risk factors for AML recurrence after allotransplantation (p < 0.05). A nomogram for the cumulative incidence of relapse (CIR) that integrated all the predictors in the multivariable model was then constructed, and the concordance index (C-index) values at 6, 12, 18, and 24 months for CIR prediction were 0.754, 0.730, 0.715, and 0.690, respectively. Moreover, calibration plots showed good agreements between the actual observation and the nomogram prediction for the 6, 12, 18, and 24 months posttransplantation CIR in the internal validation. The integrated calibration index (ICI) values were 0.008, 0.055, 0.094, and 0.136 at 6, 12, 18, and 24 months posttransplantation, respectively. With a median cutoff score of 9.73 from the nomogram, all patients could be divided into two groups, and the differences in 2-year CIR, disease-free survival (DFS), and overall survival (OS) between these two groups were significant (p < 0.05). Taken together, the results of our study indicate that gene mutations could help to predict the outcomes of patients with AML receiving allotransplantation.

CLEC-2-dependent platelet subendothelial accumulation by flow disturbance contributes to atherogenesis in mice

Rationale: Platelets play an essential role in atherosclerosis, but the underlying mechanisms remain to be addressed. This study is to investigate the role of platelets in d-flow induced vascular inflammation and the underlying mechanism. Methods: We established a disturbed blood flow (d-flow) model by partial carotid ligation (PCL) surgery using atherosclerosis-susceptible mice and wild-type mice to observe the d-flow induced platelet accumulation in the subendothelium or in the plaque by immunostaining or transmission electron microscopy. The mechanism of platelet subendothelial accumulation was further explored by specific gene knockout mice. Results: We observed presence of platelets in atherosclerotic plaques either in the atheroprone area of aortic arch or in carotid artery with d-flow using Ldlr-/- or ApoE-/- mice on high fat diet. Immunostaining showed the subendothelial accumulation of circulating platelets by d-flow in vivo. Transmission electron microscopy demonstrated the accumulation of platelets associated with monocytes in the subendothelial spaces. The subendothelial accumulation of platelet-monocyte/macrophage aggregates reached peak values at 2 days after PCL. In examining the molecules that may mediate the platelet entry, we found that deletion of platelet C-type lectin-like receptor 2 (CLEC-2) reduced the subendothelial accumulation of platelets and monocytes/macrophages by d-flow, and ameliorated plaque formation in Ldlr-/- mice on high fat diet. Supportively, CLEC-2 deficient platelets diminished their promoting effect on the migration of mouse monocyte/macrophage cell line RAW264.7. Moreover, monocyte podoplanin (PDPN), the only ligand of CLEC-2, was upregulated by d-flow, and the myeloid-specific PDPN deletion mitigated the subendothelial accumulation of platelets and monocytes/macrophages. Conclusions: Our results reveal a new CLEC-2-dependent platelet subendothelial accumulation in response to d-flow to regulate vascular inflammation.

Nonsense-mediated mRNA decay efficiency influences bleeding severity in ITGA2B c.2659C > T (p.Q887X) knock-in mice

Glanzmann's thrombasthenia (GT) is a severe hemorrhagic disease. It is caused by mutations in ITGA2B or ITGB3, which are the respective genes encoding integrin αIIb and β3. Despite widespread mutational analysis, the mechanisms underlying the extensive variability in bleeding severity observed among affected individuals remains poorly understood. In order to explore the mechanisms conferring for bleeding heterogeneity, three GT patients with ITGA2B c.2671C > T (p.Q891X) who possessed different bleeding scores were studied. Analysis showed that there was significant difference in nonsense-mediated mRNA decay (NMD) efficiency among the three patients. These differences positively correlated with their bleeding score. Next, a knock-in mouse model (KI mice) with the ITGA2B c.2659C > T (p.Q887X) was generated using CRISPR/Cas9. Importantly, this mutation is homologous to ITGA2B c.2671C > T (p.Q891X) in humans. The bleeding time of KI mice was significantly in comparison to the wide-type mice. Interestingly, bleeding was stopped after treatment with caffeine, which is a known NMD inhibitor. This suggests that NMD efficiency potentially influences bleeding severity in ITGA2B c.2659C > T (p.Q887X) KI mice.

G Protein-Coupled Estrogen Receptor Agonist G-1 Inhibits Mantle Cell Lymphoma Growth in Preclinical Models

Mantle cell lymphoma (MCL) is an aggressive form of non-Hodgkin’s B-cell lymphoma with poor prognosis. Despite recent advances, resistance to therapy and relapse remain significant clinical problems. G-protein-coupled estrogen receptor (GPER)-mediated estrogenic rapid signaling is implicated in the development of many cancers. However, its role in MCL is unknown. Here we report that GPER activation with selective agonist G-1 induced cell cycle arrest, DNA damage, mitochondria membrane potential abnormality, and eventually apoptosis of MCL cell lines. We found that G-1 induced DNA damage and apoptosis of MCL cells by promoting the expression of nicotinamide adenine dinucleotide phosphate oxidase and the generation of reactive oxygen species. In addition, G-1 inhibited MCL cell proliferation by inactivation of NF-κB signaling and exhibited anti-tumor functions in MCL xenografted mice. Most significantly, G-1 showed synergistic effect with ibrutinib making it a potential candidate for chemotherapy-free therapies against MCL.

Slc35a1 deficiency causes thrombocytopenia due to impaired megakaryocytopoiesis and excessive platelet clearance in the liver

Sialic acid is a common terminal residue of glycans on proteins and acidic sphingolipids such as gangliosides and has important biological functions. The sialylation process is controlled by more than 20 different sialyltransferases, many of which exhibit overlapping functions. Thus, it is difficult to determine the overall biological function of sialylation by targeted deletion of individual sialyltransferases. To address this issue, we established a mouse line with the Slc35a1 gene flanked by loxP sites. Slc35a1 encodes the cytidine-5’-monophosphate (CMP)-sialic acid transporter that transports CMP-sialic acid from the cytoplasm into the Golgi apparatus for sialylation. Here we report our study regarding the role of sialylation on megakaryocytes and platelets using a mouse line with significantly reduced sialylation in megakaryocytes and platelets (Plt Slc35a1– /–). The major phenotype of Plt Slc35a1–/– mice was thrombocytopenia. The number of bone marrow megakaryocytes in Plt Slc35a1–/– mice was reduced, and megakaryocyte maturation was also impaired. In addition, an increased number of desialylated platelets was cleared by Küpffer cells in the liver of Plt Slc35a1–/– mice. This study provides new insights into the role of sialylation in platelet homeostasis and the mechanisms of thrombocytopenia in diseases associated with platelet desialylation, such as immune thrombocytopenia and a rare congenital disorder of glycosylation (CDG), SLC35A1-CDG, which is caused by SLC35A1 mutations.

Blocking podoplanin inhibits platelet activation and decreases cancer-associated venous thrombosis

BACKGROUND

Patients with cancer are at a high risk of venous thromboembolism (VTE), studies have shown that high expression of podoplanin (PDPN) in tumors is associated with increased risk of VTE.

METHODS

Two human malignant cell lines (NCI-H226 and C8161) expressing high levels of PDPN were selected to explore the role of platelet in cancer-associated venous thrombosis in vitro and in vivo. Immunohistochemical staining using anti-PDPN antibody was performed in the pulmonary carcinoma patients.

RESULTS

Both NCI-H226 and C8161 cells expressing high PDPN triggered platelet activation via CLEC-2 in vitro, which was abrogated by an anti-PDPN antibody SZ-168. Furthermore, the in vivo study revealed that injection of CHO-PDPN or C8161 in two mouse model of venous thrombosis activated platelets, increased platelet counts and enhanced thrombosis. More importantly, PDPN-enhanced thrombosis was reduced in mice treated with SZ168. A total of 63.3% tumor specimens stained positive for PDPN. High PDPN expression was associated with an increased risk of VTE and poor prognosis.

CONCLUSIONS

PDPN expression in tumors induced platelet activation and was related to a high risk of VTE via platelet activation. SZ168 inhibited PDPN-induced platelet activation in vitro and decreased the incidence of VTE in mice.

Case Report: A Case With Philadelphia Chromosome Positive T-Cell Lymphoblastic Lymphoma and a Review of Literature

Philadelphia chromosome positive (Ph⁺) in T-lineage acute lymphoproliferative tumors is a rare event in both children and adults. In particular, it has not been reported in T-cell lymphoblastic lymphoma(T-LBL) yet. Here, we describe a patient with Ph⁺ T-LBL for both cytogenetic abnormality and BCR-ABL1 fusion transcript. Moreover, we review the published cases of Ph⁺ T-cell acute lymphoblastic leukemia (T-ALL) in the literature and summarize their clinical characteristics, management, and prognosis.

Identification of a novel TNRC18-RARA fusion in acute promyelocytic leukemia lacking t(15;17)(q24;q12)/PML-RARA

Acute promyelocytic leukemia (APL) is a unique disease entity in acute myeloid leukemia, characterized by PML-RARA fusion gene, which is generated by chromosomal translocation t(15;17)(q24;q21). We identified TNRC18-RARA as novel RARA fusion in resembling APL. Our study highlights the importance of combining multiple molecular techniques to characterize and optimally manage APL lacking classic t(15;17)(q24;q12)/PML-RARA fusion.

Identification of a Novel CSNK2A1-PDGFRB Fusion Gene in a Patient with Myeloid Neoplasm with Eosinophilia

Platelet-derived growth factor receptor beta (PDGFRB) rearrangements play an important role in the pathogenesis of eosinophilia-associated myeloid/lymphoid neoplasms. Up to now, more than 70 PDGFRB fusions have been identified. Here, a novel PDGFRB fusion gene CSNK2A1-PDGFRB has been identified in myeloproliferative neoplasm (MPN) with eosinophilia by RNA-sequencing, which has been verified by reverse transcription polymerase chain reaction and Sanger sequencing. The new PDGFRB fusion partner gene CSNK2A1 encoded one of the two catalytic subunit of casein kinase II (CK2). To our knowledge, this is the first report on the involvement of CSNK2A1 in fusion genes, especially fusion with another kinase PDGFRB in MPN. In addition, the CSNK2A1-PDGFRB fusion retained the entire kinase domain of PDGFRB and response to imatinib at low concentration. The patient with CSNK2A1-PDGFRB was sensitive to imatinib treatment and acquired sustained complete remission.

The Detection of Plasma Soluble Podoplanin of Patients with Breast Cancer and Its Clinical Signification

Background

Podoplanin (PDPN) is a type-1 membrane sialoglycoprotein that is expressed in many cancer tumors including breast cancer; nonetheless, its roles in tumor occurrence, development, and metastasis are unclear. In this study, we aimed to investigate the clinical significance of plasma soluble PDPN (sPDPN) levels in patients with breast cancer and its significance in the diagnosis and metastasis.

Materials and Methods

Blood samples from healthy controls (CTL), patients with fibroadenomas of breast (FOB), and breast cancer (pathological type: invasive ductal carcinoma, IDC) were collected. sPDPN levels in the plasma of CTL and patients with FOB and IDC were measured by the ELISA.

Results

The plasma sPDPN levels in IDC patients (159 cases, 22.59±3.70 ng/mL) were higher than those in FOB patients (50 cases, 8.29±1.09 ng/mL; P<0.05) and CTL (100 cases, 1.21±0.12 ng/mL; P<0.0001). The sPDPN levels in patients at stage III and stage IV (30.08±4.66 ng/mL) were higher than in patients at stage I and stage II (11.84±1.12 ng/mL; P=0.005). The sPDPN levels in patients with high-moderate and moderate differentiation (17.50±3.02 ng/mL) were lower than those in patients with moderately low and low differentiation (35.73±4.26 ng/mL; P=0.026). The sPDPN levels in patients with metastasis (30.60±4.27 ng/mL) were much higher than those in patients without metastasis (13.02±1.30 ng/mL; P=0.017).

Conclusion

Plasma sPDPN may be used as a new marker for the determination of the clinical stage, differentiation degree, and metastasis status of breast cancer.

Investigation of fibrinogen in early bleeding of patients with newly diagnosed acute promyelocytic leukemia

Early hemorrhagic death remains a major cause of treatment failure in acute promyelocytic leukemia (APL). This study investigated the role of fibrinogen concentrations in early hemorrhage and overall survival (OS) of APL patients. Laboratory and clinical data, including fibrinogen concentrations and other coagulation indexes, bleeding events, and survival data, of 198 patients newly diagnosed with APL from February 2012 to December 2017 were extracted from patient records and retrospectively investigated. Patients with moderate/severe bleeding had significantly lower median fibrinogen concentrations (p = .023), higher Chinese disseminated intravascular coagulation scoring system (CDSS) (p < .001), and were more often female (p = .034) than patients with no such bleeding. Additionally, patients with fibrinogen <1.0 g/L and 1.0-1.6 g/L had significantly higher moderate/severe bleeding rates than those with fibrinogen >1.6 g/L (p = .015; p = .023). However, moderate/severe (p = .088) and severe bleeding rates (p = .063) were comparable for patients with fibrinogen <1.0 g/L and 1.0-1.6 g/L. Multivariate analysis showed that fibrinogen ≤1.6 g/L (p = .036), platelet counts ≤10 × 10⁹/L (p = .037), and CDSS scores ≥5 (p = .023) were independent risk factors for moderate/severe bleeding. Survival analysis indicated that moderate/severe bleeding (p = .018), fibrinogen ≤1.6 g/L combined with prothrombin time >12.8 s (p = .005), age ≥60 years (p = .001), and CDSS ≥5 (p = .044) were independent predictors of 1-year OS. Fibrinogen ≤1.6 g/L may be an independent risk factor for early bleeding in newly treated patients with APL and is associated with a worse 1-year OS. Increasing fibrinogen to >1.6 g/L may help to prevent bleeding.

Monocyte upregulation of podoplanin during early sepsis induces complement inhibitor release to protect liver function

Multiple organ failure in sepsis is a progressive failure of several interdependent organ systems. Liver dysfunction occurs early during sepsis and is directly associated with patient death; however, the underlying mechanism of liver dysfunction is unclear. Platelet transfusion benefits patients with sepsis, and inhibition of complement activation protects liver function in septic animals. Herein, we explored the potential link between platelets, complement activation, and liver dysfunction in sepsis. We found that deletion of platelet C-type lectin-like receptor 2 (CLEC-2) exacerbated liver dysfunction in early sepsis. Platelet CLEC-2-deficient mice exhibited higher complement activation, more severe complement attack in the liver, and lower plasma levels of complement inhibitors at early time points after E. coli infection. Circulating monocytes expressed the CLEC-2 ligand podoplanin in early sepsis, and podoplanin binding induced release of complement inhibitors from platelets. Injection of complement inhibitors released from platelets reduced complement attack and attenuated liver dysfunction in septic mice. These findings indicate a new function of platelets in the regulation of complement activation during sepsis.

The prognostic value of plasma fibrinogen level in patients with acute myeloid leukemia: a systematic review and meta-analysis

Increasing evidence has revealed that plasma fibrinogen levels may serve as prognostic indicators in patients with acute myeloid leukemia (AML), yet the exact association is still elusive. We conducted a systematic review and meta-analysis of all available studies concerning the relationship between plasma fibrinogen level and survival in AML patients. The pooled hazard ratio (HR) and 95% confidence intervals (CIs) for overall survival (OS) were calculated to evaluate the effect. A random-effect model was applied and the robustness of the pooled results was confirmed by subgroup and sensitivity analysis. A total of 9 studies were eligible to assess the association between plasma fibrinogen level and prognosis in AML. Among these investigations above, 5 studies adopted OS as their outcome indicator and were selected for the final meta-analysis. The pooled result suggested that plasma fibrinogen level was significantly relevant to increased mortality risk in AML patients (HR = 1.21, 95% CI: 1.01-1.44, p = .000, I²=85.4%). In conclusion, high plasma fibrinogen level may independently predict worse OS in patients with AML.

TBL1XR1 mutation predicts poor outcome in primary testicular diffuse large B-cell lymphoma patients

Primary testicular lymphoma (PTL), often appearing as focal masses in the scrotum and epididymides, is the most frequent testicular tumor in aged men. Although MYD88 and CD79B mutations were the most common genetic alterations observed, the gene mutation landscape of PTL remains poorly defined. In this study, we identified 1326 mutations involving 311 genes or regions in 90 PTL patients through next-generation sequencing (NGS). PTL patients with the TBL1XR1 mutation, irrespective of treatment therapy, had an inferior overall survival (OS) than TBL1XR1 WT (wild type) patients (p = 0.045). Moreover, patients with this mutation, treated with a CHOP regimen (CTX 750 mg/m² iv, d1,8 ADM 50 mg/m² iv, d1 VCR 1.4 mg/m² iv, d1 PDN 100 mg/m² po d1–5), had a poorer OS (p = 0.019). In addition, such patients were prone to have a more intensive infiltration of tumors (p = 0.025, x² = 4.890). Thus, we speculated that patients with a TBL1XR1 mutation have poorer prognosis, partly due to greater invasion and infiltration of tumors. Our results suggest that the TBL1XR1 mutation can be used as an indicator to predict the prognosis of PTL and can be employed as a promising new target for treatment of PTL in the future.

Novel mutations in ADAMTS13 CUB domains cause abnormal pre-mRNA splicing and defective secretion of ADAMTS13

Hereditary thrombotic thrombocytopenic purpura (TTP) is an autosomal recessive thrombosis disorder, caused by loss-of-function mutations in ADAMTS13. Mutations in the CUB domains of ADAMTS13 are rare, and the exact mechanisms through which these mutations result in the development of TTP have not yet been fully elucidated. In this study, we identified two novel mutations in the CUB domains in a TTP family with an acceptor splice-site mutation (c.3569-1, G>A, intron 25) and a point missense mutation (c.3923, G>A, exon 28), resulting in a glycine to aspartic acid substitution (p.G1308D). In vitro splicing analysis revealed that the intronic mutation resulted in abnormal pre-mRNA splicing, and an in vitro expression assay revealed that the missense mutation significantly impaired ADAMTS13 secretion. Although both the patient and her brother displayed significantly reduced ADAMTS13 activity and increased levels of ultra-large VWF (ULVWF) multimers in plasma, only the female developed acute episodes of TTP. Our findings indicate the importance of the CUB domains for the protein stability and extracellular secretion of ADAMTS13.

Elevated Plasma von Willebrand Factor Antigen and Activity Levels Are Associated With the Severity of Coronary Stenosis

von Willebrand factor (VWF) acts as a bridge between platelets and the subendothelial matrix following vessel damage and plays a vital role in coronary artery disease (CAD). The aim of this study was to investigate the association between VWF and the severity of coronary stenosis quantified by the Gensini score in acute myocardial infarction (AMI), the most dangerous complication of CAD. Plasma VWF antigen (VWF: Ag) and VWF-collagen binding (VWF: CB) in normal controls (n = 123) and in patients with AMI (n = 205) were tested, and then the patients were divided based on Gensini scores. The levels of VWF: Ag and VWF: CB in patients with AMI were significantly higher than those in the control group (P < .001). Plasma levels of VWF: Ag and VWF: CB were positively correlated with both Gensini score and the number of affected vessels. Both VWF: Ag and VWF: CB were independent factors for coronary stenosis, adjusting confounding factors. Thus, the levels of VWF: Ag and VWF: CB were positively correlated with the severity of coronary stenosis. Screening of VWF at time of AMI may have prognostic value in terms of the severity of coronary stenosis.

Efficacy and Safety of Defibrotide for the Treatment of Hepatic Veno-Occlusive Disease after Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

Defibrotide has been approved in several geographic jurisdictions for the treatment of hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) for years. However, available data on efficacy and safety for its use in VOD are contrasting. We performed a meta-analysis to evaluate the efficacy and safety of defibrotide in the treatment of hepatic VOD/SOS post-hematopoietic stem cell transplantation (HSCT). PubMed and Embase were searched for studies regarding the efficacy and safety of defibrotide in VOD patients. Survival rate at day + 100 post-HSCT (D + 100 SR), as well as the prognosis, comprising complete response (CR), adverse events including ≥1 adverse event (≥1 AE), hemorrhage, and serious adverse events (SAEs), were pooled using a random effect model. Sixteen studies involving 3,002 participants were included. Pooled estimates for overall D + 100 SR as well as rate of CR, ≥1 AE, hemorrhage, SAEs in VOD patients post-HSCT were 58% (95% CI: 54-62%), 57% (95% CI: 45-68%), 65% (95% CI: 54-75%), 16% (95% CI: 5-27%), 53% (95% CI: 51-55%), respectively, and were 44% (95% CI: 39-48%), 39% (95% CI: 28-50%), 88% (95% CI: 71-100%), 42% (95% CI: 30-55%), 58% (95% CI: 52-64%), respectively, in severe VOD (sVOD) patients. Hemorrhage and hypotension were the most common AEs. Current evidence suggests that defibrotide improves the D + 100 SR and CR in VOD/sVOD patients following HSCT. However, the results of this review/meta-analysis were mainly based on data from observational studies, potentially subject to selection bias. Consequently, higher quality randomized control trials and larger prospective cohort studies are warranted.

Plasma soluble C-type lectin-like receptor-2 is associated with the risk of coronary artery disease

Accumulating evidence suggests that C-type lectin-like receptor-2 (CLEC-2) plays an important role in atherothrombosis. In this case-control study, we investigated the association between CLEC-2 and incidence of coronary artery disease (CAD). A total of 216 patients, including 14 cases of stable angina pectoris (SAP, non-ACS) and 202 cases of acute coronary syndrome (ACS), and 89 non-CAD control subjects were enrolled. Plasma levels of soluble CLEC-2 (sCLEC-2) were measured using the enzyme-linked immunosorbent assay (ELISA). Compared with the control group (65.69 (55.36-143.22) pg/mL), the plasma levels of sCLEC-2 were significantly increased in patients with CAD (133.67 (88.76-220.09) pg/mL) and ACS (134.16 (88.88-225.81) pg/mL). The multivariate adjusted odds ratios (95% confidence interval) of CAD reached 2.01 (1.52-2.66) (P_trend < 0.001) for each 1-quartile increase in sCLEC-2. Restricted cubic splines showed a positive dose-response association between sCLEC2 and CAD incidence (P_linearity < 0.001). The addition of sCLEC-2 to conventional risk factors improved the C statistic (0.821 vs. 0.761, P = 0.004) and reclassification ability (net reclassification improvement: 57.45%, P < 0.001; integrated discrimination improvement: 8.27%, P < 0.001) for CAD. In conclusion, high plasma sCLEC-2 is independently associated with CAD risk, and the prognostic value of sCLEC-2 may be evaluated in future prospective studies.

Clinical characteristics and prognostic significance of chronic myeloid leukemia with rare BCR-ABL1 transcripts

The prognostic significance of rare BCR-ABL1 transcripts is uncertain in the tyrosine kinase inhibitor (TKI) era. In this retrospective study, 40 (1.7%) patients with rare BCR-ABL1 transcripts were identified from a cohort of 2331 chronic myeloid leukemia (CML) patients; 4 types of rare transcripts were identified, including e1a2 (0.9%), e19a2 (0.4%), e13a3 (0.1%), and e14a3 (0.3%). Compared to patients with the typical transcript, those with the e1a2 transcript had an inferior response to TKIs and a worse outcome. Patients with the e19a2 transcript had a high rate of early optimal response to TKIs, but most of them later lost the complete cytogenetic response (CCyR) due to BCR-ABL1 mutations, resulting in a poor prognosis. Patients with the e13a3/e14a3 transcript responded well to TKIs and had a good outcome. These findings indicate that the type of BCR-ABL1 transcript should be considered when determining the treatment for CML patients in the TKI era.

Blocking podoplanin suppresses growth and pulmonary metastasis of human malignant melanoma

Background

Podoplanin (PDPN), a transmembrane O-glycoprotein, is up-regulated in many tumors and is involved in tumor metastasis and malignant progression. In previous studies, we generated a functional blocking monoclonal antibody (mAb, SZ168) against the extracellular domain of human PDPN. This study is aimed to investigate whether blocking PDPN by SZ168 inhibits tumor growth and metastasis.

Methods

Malignant melanoma xenograft model by inoculating subcutaneously human malignant melanoma cell line C8161 into the back of BALB/c nude mice was used. Endogenous PDPN expression in C8161 cells and nasopharyngeal cancer cell line CNE-2 was detected using western blot and flow cytometry.

Results

SZ168 significantly inhibited C8161 or CNE-2 cell-induced platelet aggregation in a dose-dependent manner with a maximal inhibition of 73.9 ± 3.0% in C8161 cells or 77.1 ± 2.7% in CNE-2 cells. Moreover, SZ168 inhibited the growth and pulmonary metastasis of C8161cells in vivo. The number of lung metastatic foci in the SZ168-treated group was significantly decreased compared with that in the control mouse IgG group (1.61 ± 0.44 vs.3.83 ± 0.60, P < 0.01). Subcutaneous tumor volume, weight, and incidence were also significantly reduced in the SZ168-treated group compared to the control group (P < 0.05). Additionally, SZ168 recognized PDPN in immunohistochemical analyses of tumor tissue sections.

Conclusions

SZ168 blocks growth and pulmonary metastasis of human malignant melanoma by inhibiting the interaction between tumor PDPN and platelet CLEC-2 and therefore is a promising antibody for therapeutic development against malignant melanoma.

Overexpression of ZEB2-AS1 lncRNA is associated with poor clinical outcomes in acute myeloid leukemia

Acute myeloid leukemia (AML) is a fatal hematopoietic malignancy with poor clinical outcomes. To determine whether the expression of the long non-coding (lnc)RNA zinc finger E-box binding homeobox 2 (ZEB2) antisense RNA 1 (ZEB2-AS1) is associated with clinical outcomes, its expression was analyzed in a retrospective cohort of 62 AML and 10 non-malignant cases. The results revealed that the expression of ZEB2-AS1 lncRNA was notably high and closely associated with adverse clinical outcomes in AML cases compared with the non-malignant cases, based on either modified Medical Research Council or European Leukemia Net risk stratification systems. Univariate analyses indicated that patients with a higher expression of ZEB2-AS1 lncRNA had significantly shorter overall survival (OS) (P=0.036) and disease-free survival (DFS) rates (P=0.039) compared with patients with a lower expression of ZEB2-AS1 lncRNA. In addition, patients with a higher expression of ZEB2-AS1 lncRNA had a significant lower complete remission rate in response to induction by chemotherapy compared with patients with a lower expression of ZEB2-AS1 lncRNA (P=0.031). In cases with low levels of ZEB2-AS1 lncRNA, patients treated with allogenic hematopoietic stem cell transplantation had significantly longer OS and DFS rates compared with that of chemotherapy-treated patients (P=0.037 and P=0.049 respectively). Furthermore, the knockdown of ZEB2-AS1 lncRNA effectively inhibited AML cell invasion and migration, which was closely associated with the downregulation of ZEB2 and upregulation of E-cadherin expression. Collectively, although its independent prognostic value for survival was not rigorously determined, ZEB2-AS1 lncRNA may function as a candidate marker to improve conventional risk stratification systems and the evaluation of therapeutic responses for AML.

[Clinical observation of desmopressin in the treatment of 15 patients with DDAVP]

Objective: To assess the significance of DDAVP use in the diagnosis and treatment of VWD. Methods: An analysis of 15 VWD cases who referred to Hematology Division of First affiliated Hospital of Soochow University and treated with DDAVP from March 2016 to August 2018 was conducted. Efficacy and treatment response of DDAVP were monitored by observations of changes in factor Ⅷ procoagulant (FⅧ∶C) and von Willebrand Factor (VWF) related indicators before and 2 h after DDAVP injection. Results: Of 15 cases with VWD, 7 males and 8 females with a median age of 23 (6-46) years, 7 of 9 type I VWD patients achieved complete response (CR) , 1 type 2A VWD case CR, 5 type 3 VWD ones no response (NR) . The VWF multimer analysis in 5 patients combined with other plasma VWF values were in accordance with the known diagnosis. Conclusions: DDAVP was effective in most type 1 patients, and ineffective in some type 2 and almost all type 3 cases. It was helpful for diagnosis and subsequent treatment planning.

[Clinical features of 20 patients with phytosterolemia causing hematologic abnormalities]

Objective: To investigate the clinical and laboratory features of Phytosterolemia with hematological abnormalities. Methods: A retrospective study was performed on 20 patients with phytosterolemia admitted to the hematology department of the First Affiliated Hospital of Suzhou University during 2004-2017. History of patients was collected and the platelet counts, lipidomic analysis of plasma and osmotic fragility of erythrocytes were carried out. The erythrocyte and platelet morphology was examined by light microscope. Phytosterol levels in serum were measured by high performance liquid chromatography method. All of ABCG5/8 exons and intron-exon boundaries were amplified by PCR and directly sequenced to identify mutations. Results: All patients had been misdiagnosed as immune thrombocytopenia (ITP), or Evans syndrome with a mean delay of 21 years between symptom onset and accuracy diagnosis. The clinical manifestations of the patients were variable, but most of them presented with thrombocytopenia, anemia, splenomegaly from early ages, and xanthomas. Other major features were also observed, such as impaired liver functions (9 cases), premature atherosclerosis (5 cases) and/or arthritis (4 cases). Interestingly, all patients displayed an increased osmotic fragility of red cells and unique blood film features: large unequal platelets surrounded by a circle of vacuoles and various abnormal erythrocyte shapes, especially stomatocyte. Serum levels of the sitosterol and stigmasterol in the patients were remarkably elevated up to 331.05(276.00, 670.20)mg/L and 244.60(193.78,399.40)mg/L, about 10 and 24 times higher than those of normal subjects. There were 14 mutations in ABCG5/8 genes found in the patients. Among them, 2/3 of the mutations were in ABCG5 gene, including p.(E22X), p.(R446X),g.ISV7+3G>A, p.(R446X), p.(R419H), g.ISV7+3G>A, p.(G90E), p.(R389H) and g.7+2G>A), and 1/3 in ABCG8 gene involving p.(M614-K628del), p.(E25X), p.(L86P fs X185), p.(R263Q), p.(E500D fs X604) and p.(G674R) mutation. The ABCG5 p.(R446X) mutation was found in 3 separate families. Conclusions: The phenomena of thrombocytopenia/ stomatocyte/splenomegaly represents a special clinical manifestations of phytosterolemia, and distinct changes of blood cell morphology are the typical characters. Plasma plant sterols and ABCG5/ABCG8 genes should be analyzed when such hematologic abnormalities are unexplained.

[α1-antitrypsin Pittsburg mutations: report of two cases in the same family]

目的

分析2例α1抗胰蛋白酶（α1-AT）Pittsburg突变患者的临床和实验室特点。

方法

采用凝固法或发色底物法分别检测凝血时间及凝血因子活性；比浊法测定血小板聚集功能；采用毛细管电泳法测定血清蛋白；PCR扩增目的DNA片段并测序检测突变。

结果

先证者，女，34岁，多次术后出血及黄体破裂出血；女儿，10岁，无出血表现。两例患者APTT、凝血酶时间均明显延长且正常人混和血浆1∶1不能纠正，凝血因子Ⅸ、Ⅹ、Ⅺ、Ⅻ活性明显降低，蛋白C、蛋白S活性均为0，1 U/ml凝血酶诱导的血小板聚集降低，4 U/ml凝血酶诱导的血小板聚集为48%；血清α1球蛋白电泳条带异常；DNA测序结果显示两例患者的α1-AT基因（NG_008290.1）均存在g.T17132G（p.Met358Arg）杂合突变。

结论

α1-AT Pittsburg突变患者表现出明显的凝血异常，临床出血表现有较大的差异性，黄体破裂出血可能是女性患者的一个明显特征。

Serum semaphorin 7A is associated with the risk of acute atherothrombotic stroke

Semaphorin 7A (Sema7A), a neural guidance cue, was recently identified to regulate atherosclerosis in mice. However, the clinical relevance of Sema7A with atherosclerotic diseases remains unknown. The aim of this study was to investigate the association between serum Sema7A and the risk of acute atherothrombotic stroke (AAS). We measured serum concentrations of Sema7A in 105 newly onset AAS cases and 105 age‐ and sex‐matched controls, showing that median Sema7A level in AAS cases was over three times of that in controls (5.86 vs 1.66 ng/mL). Adjusted for hypertension, body mass index, fasting blood glucose, total cholesterol, triglyceride, high‐density lipoprotein (HDL)‐cholesterol, low‐density lipoprotein (LDL)‐cholesterol, current smoking and alcohol consumption, multivariate logistic regression showed that higher Sema7A was independently associated with the odds of AAS (OR = 6.40, 95% CI: 2.88‐14.25). Each 1‐standard deviation increase in Sema7A was associated with a threefold higher odds of AAS (OR = 3.42, 95% CI: 1.84‐6.35). Importantly, adding Sema7A to a multivariate logistic model containing conventional cardiovascular risk factors improved the area under receiver operating characteristic curves from 0.831 to 0.891 for the association with AAS. In conclusion, elevated serum Sema7A is independently associated with the risk of AAS, suggesting that it may play a potential role in AAS.

Prognostic Significance of Platelet Recovery in Myelodysplastic Syndromes With Severe Thrombocytopenia

Severe thrombocytopenia is a serious condition that frequently arises in patients with myelodysplastic syndrome (MDS) and is associated with poor prognosis. Few studies have investigated the prognostic significance of platelet recovery in patients with MDS having thrombocytopenia. We retrospectively analyzed 117 patients with de novo MDS complicated with thrombocytopenia (platelet count [PLT] < 100 × 10⁹/L). Patients received decitabine treatment (schedule A) or decitabine followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT; schedule B). Severe thrombocytopenia (PLT < 20 × 10⁹/L), identified in 31 (26.5%) patients, was associated with poor survival. The PLT increased significantly after decitabine treatment in the 2 groups. Patients with thrombocytopenia treated with schedule B showed a superior prognosis compared to those treated with schedule A. On analysis of overall survival by platelet response in patients with severe thrombocytopenia, a significant survival advantage was observed in patients who achieved a platelet response, who would further benefit from allo-HSCT following decitabine therapy. The results indicate a potentially favorable prognostic impact of platelet response achieved with decitabine. Patients with MDS having severe thrombocytopenia may benefit from the effective recovery of platelets and further allo-HSCT following decitabine therapy.

Application of High-Throughput Sequencing in the Diagnosis of Inherited Thrombocytopenia

Inherited thrombocytopenia is a group of hereditary diseases with a reduction in platelet count as the main clinical manifestation. Clinically, there is an urgent need for a convenient and rapid diagnosis method. We introduced a high-throughput, next-generation sequencing (NGS) platform into the routine diagnosis of patients with unexplained thrombocytopenia and analyzed the gene sequencing results to evaluate the value of NGS technology in the screening and diagnosis of inherited thrombocytopenia. From a cohort of 112 patients with thrombocytopenia, we screened 43 patients with hereditary features. For the blood samples of these 43 patients, a gene sequencing platform for hemorrhagic and thrombotic diseases comprising 89 genes was used to perform gene detection using NGS technology. When we combined the screening results with clinical features and other findings, 15 (34.9%) of 43patients were diagnosed with inherited thrombocytopenia. In addition, 19 pathogenic variants, including 8 previously unreported variants, were identified in these patients. Through the use of this detection platform, we expect to establish a more effective diagnostic approach to such disorders.

Site-1 protease deficiency causes human skeletal dysplasia due to defective inter-organelle protein trafficking

Site-1 protease (S1P), encoded by MBTPS1, is a serine protease in the Golgi. S1P regulates lipogenesis, endoplasmic reticulum (ER) function, and lysosome biogenesis in mice and in cultured cells. However, how S1P differentially regulates these diverse functions in humans has been unclear. In addition, no human disease with S1P deficiency has been identified. Here, we report a pediatric patient with an amorphic and a severely hypomorphic mutation in MBTPS1. The unique combination of these mutations results in a frequency of functional MBTPS1 transcripts of approximately 1%, a finding that is associated with skeletal dysplasia and elevated blood lysosomal enzymes. We found that the residually expressed S1P is sufficient for lipid homeostasis but not for ER and lysosomal functions, especially in chondrocytes. The defective S1P function specifically impairs activation of the ER stress transducer BBF2H7, leading to ER retention of collagen in chondrocytes. S1P deficiency also causes abnormal secretion of lysosomal enzymes due to partial impairment of mannose-6-phosphate-dependent delivery to lysosomes. Collectively, these abnormalities lead to apoptosis of chondrocytes and lysosomal enzyme-mediated degradation of the bone matrix. Correction of an MBTPS1 variant or reduction of ER stress mitigated collagen-trafficking defects. These results define a new congenital human skeletal disorder and, more importantly, reveal that S1P is particularly required for skeletal development in humans. Our findings may also lead to new therapies for other genetic skeletal diseases, as ER dysfunction is common in these disorders.

Altered circulating T follicular helper cells in patients with chronic immune thrombocytopenia

The present study aimed to illuminate the role of circulating T follicular helper (TFH) cells in patients diagnosed with chronic immune thrombocytopenia (cITP). Fifty-four patients with cITP and 30 age-matched healthy control subjects were enrolled in the present study. TFH cell frequencies, expression of CD4⁺ TFH cell-associated cytokines, including interleukin (IL)-2, IL-4, IL-10 and IL-21 and associated regulatory mRNA expression levels including Bcl-6, c-Maf, Blimp-1 and PD-1 pre- and post-treatment with intravenous immunoglobulin and corticosteroids, were detected by flow cytometry, ELISA and reverse transcription-quantitative polymerase chain reaction, respectively. TFH cell frequencies of patients were significantly higher compared with healthy controls pre-treatment (P<0.05). Following treatment, significantly decreased percentages of TFH cells were present in cITP responders (P<0.05). Correlation analysis revealed that the number of TFH cells was negatively correlated with the platelet count in the peripheral blood. Furthermore, analysis of inflammatory cytokines indicated significant differences in serum interleukin (IL)-21 and IL-10 between pretreated patients and healthy controls (P<0.05). Additionally, transcription factor B-cell lymphoma (Bcl)-6, c-Maf and programmed death-ligand (PD)-1 mRNA expression levels were significantly different between cITP patients prior to treatment and the healthy controls (P<0.05). However, the expression levels of Bcl-6, C-Maf and PD-1 mRNA were significantly changed post-treatment (P<0.05). These data demonstrated that circulating TFH cells and CD4⁺ TFH cell-associated cytokines may serve a role in cITP. The findings suggest that the overactivation of TFH cells may contribute to the immunopathogenesis of cITP, thus blocking the pathway of TFH cells may be reasonable for therapeutic intervention.