[Outcomes of allogeneic hematopoietic stem cell transplantation for 18 patients with paroxysmal nocturnal haemoglobinuria]

目的

评价异基因造血干细胞移植（allo-HSCT）治疗阵发性睡眠性血红蛋白尿症（PNH）的疗效。

方法

回顾性分析2007年12月至2015年2月间接受allo-HSCT治疗的18例PNH患者临床资料，其中原发PNH 4例，再生障碍性贫血-PNH综合征（AA-PNH）14例。9例为单倍体相同供者移植（其中1例为双份脐血植入失败后行挽救性单倍体相同供者移植），7例为HLA相合同胞供者移植，2例为HLA相合无关供者移植。13例患者接受改良白消安/环磷酰胺方案为主的清髓性预处理，5例接受非清髓性预处理（氟达拉滨+抗胸腺细胞球蛋白+环磷酰胺或白消安方案）。移植物抗宿主病（GVHD）预防：同胞供者移植为环孢素联合短程甲氨蝶呤，单倍体相同供者及无关供者移植为环孢素或他克莫司、霉酚酸酯联合短程甲氨蝶呤。

结果

所有患者均获造血重建（其中1例患者脐血植入失败后行单倍体相同供者移植）。中性粒细胞绝对计数≥0.5×10⁹/L的中位时间为移植后11（10~26）d，PLT恢复至≥20×10⁹/L的中位时间为移植后15（11~120）d。3例（17.6%）患者发生急性GVHD（aGVHD），其中Ⅱ度2例，Ⅳ度1例。2例（12.5%）发生局限型慢性GVHD（cGVHD）。中位随访14.6（2.0～86.7）个月，18例患者中死亡3例（17.6%），死因分别为重度aGVHD、肺部重症感染、肺部感染合并移植相关血栓性微血管病。预期5年无病生存率为（80.5±10.2）%。无复发病例。

结论

allo-HSCT治疗PNH疗效确切，预后良好，在抗补体C5单抗尚未广泛应用的情况下，可作为有价值的治疗手段。

Use of recombinant factor VIIa in uncontrolled gastrointestinal bleeding after hematopoietic stem cell transplantation among patients with thrombocytopenia

Background and Objective:

Recombinant-activated factor VII (rVIIa) is a vitamin K-dependent glycoprotein that is an analog of the naturally occurring protease. It has an off-label use to control life-threatening bleeding that is refractory to other measures and was shown to decrease transfusion requirements. Gastrointestinal (GI) bleeding is a severe complication following hematopoietic stem cell transplantation (HSCT) in patients with thrombocytopenia, while hemostatic measures based on antifibrinolytic or transfusion therapy may not always be successful. The present study investigated the treatment with rFVIIa in severe GI bleeding among thrombocytopenia patients undergoing HSCT.

Methods:

rFVIIa was given as a single dose of 60μg/kg in patients with GI bleeding following hematopoietic stem cell transplantation (HSCT).

Results:

Among all patients enrolled, 12 (75%) of 16 patients obtained a response, of which 5 achieved a complete response and 7 achieved a partial response. The 4 remiaing patients (25%) had no response. Nine patients (56.3%) died in a follow-up of 90 days. No thromboembolic events wereassociated with the drug administration occurred.

Conclusions:

Our study showed that rFVIIa may represent an additional therapeutic option in such cases.

[Stable expression of recombinant human podoplanin in Chinese hamster ovary (CHO) cells]

OBJECTIVE

To construct podoplanin (PDPN) eukaryotic expression plasmid PDPN-pEGFP-N1, establish Chinese hamster ovary (CHO) cell line stably expressing recombinant human PDPN and investigate its biological activity.

METHODS

PDPN cDNA was cloned from HEK293 cells by reverse transcription PCR and recombinant DNA technology and inserted into plasmid pEGFP-N1 labeled by enhanced green fluorescent protein (EGFP). The recombinant vector was identified by PCR, restriction enzyme digestion and DNA sequencing, and then transfected into CHO cells. Recombinant PDPN-EGFP was observed by fluorescent microscopy and CHO cell line with the high expression of PDPN-EGFP was selected by flow cytometry. Recombinant PDPN was detected by Western blotting and the biological activity of the cell line was determined by platelet aggregation assay.

RESULTS

DNA sequencing and restriction enzyme digestion proved that the gene of PDPN was inserted successfully into pEGFP-N1 plasmid. After stable transfection of the recombinant plasmid into CHO cells, CHO with EGFP could be seen under a fluorescent microscope. The CHO cell line with the high expression of recombinant PDPN-EGFP was obtained after sorting by flow cytometry. Western blotting showed that the recombinant PDPN was expressed on the cell surface. The over-expressing PDPN-EGFP CHO cells were able to induce human platelet aggregation.

CONCLUSION

The CHO cell line with the stable and high expression of recombinant PDPN-EGFP has been constructed successfully, and it could induce platelet aggregation.

Decitabine for Treatment of Myelodysplastic Syndromes in Chinese Patients: An Open-Label, Phase-3b Study

Introduction

The objective of this study was to evaluate the efficacy and safety of decitabine in Chinese patients with myelodysplastic syndrome (MDS).

Methods

Patients (≥18 years) who had a de novo or secondary MDS diagnosis according to French–American–British classification and an International Prognostic Scoring System score ≥0.5 were enrolled and randomized (1:1) to one of two decitabine regimens: 3-day treatment (3-h intravenous infusion of 15 mg/m² given every 8 h for three consecutive days/cycle/6 weeks) or 5-day treatment (1-h intravenous infusion of 20 mg/m² once daily on days 1–5/cycle/4 weeks). After a minimum of 30 patients were assigned to 3-day schedule, the remaining were assigned to the 5-day schedule. The primary efficacy endpoint was the overall response rate (ORR). Secondary outcome measures included hematologic improvement (HI), cytogenetic response rate, the time to acute myeloid leukemia (AML) progression, and overall survival (OS).

Results

In total, 132 of 135 enrolled patients (3-day treatment, n = 36; 5-day treatment, n = 99) discontinued treatment (major reasons included patient withdrawal/lack of efficacy, n = 48; adverse events, n = 23; and disease progression, n = 22). During the study, 35 of 132 (26.5%) patients from the intent-to-treat (ITT) group achieved significant (P < 0.001) ORR [3-day group (n = 10, 29.4%), P = 0.003; 5-day group (n = 25, 25.5%), P < 0.001]. The HI rate was similar between the 3-day (47.1%) and 5-day groups (48.0%). Cytogenetic response was achieved in 20 of the 30 (66.7%) patients who had a baseline cytogenetic abnormality. Fifty-three (40.2%) AML transformations or deaths occurred and the median AML-free survival time was 23.8 months for all patients from the ITT set; 24-month OS rate was 48.9%. Adverse events of myelosuppression-related disorders (85.6%) and infections (43.2%) were commonly reported.

Conclusion

Decitabine treatment was efficacious in Chinese patients with MDS with its safety profile comparable to the global studies of decitabine conducted to date.

Funding

Xian-Janssen Pharmaceutical Ltd. China (a company of Johnson & Johnson).

Trial registration

ClinicalTrials.gov identifier, NCT01751867.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-015-0263-8) contains supplementary material, which is available to authorized users.

Characterization of a Novel Integrin Binding Protein, VPS33B, Which Is Important for Platelet Activation and In Vivo Thrombosis and Hemostasis

BACKGROUND

Integrins are heterodimeric (α/β) membrane proteins that play fundamental roles in many biological processes, for example, cell adhesion and spreading, which are important for platelet function and hemostasis. The molecular mechanism that regulates integrin activation is not completely understood.

METHODS AND RESULTS

Here, we show that VPS33B, a member of the Sec1/Munc18 family, binds directly to the integrin β subunit. Overexpression of VPS33B in Chinese hamster ovary cells potentiated αIIbβ3 outside-in signaling but not inside-out signaling. Platelets, from megakaryocyte- and platelet-specific VPS33B conditional knockout mice, had normal morphology, yet their spreading on fibrinogen was impaired and they failed to support clot retraction. Platelet aggregation and ATP secretion in response to low-dose agonists were reduced in the VPS33B knockout mice. αIIbβ3-mediated endocytosis of fibrinogen was also defective. Tail bleeding times and times to occlusion in an FeCl3-induced thrombosis model were prolonged in the VPS33B knockout mice. Furthermore, VPS33B acted upstream of the RhoA-ROCK-MLC and Rac1-dependent pathways that lead to clot retraction and cell spreading, respectively.

CONCLUSIONS

Our work demonstrates that vesicular trafficking complexes, containing VPS33B, are a novel class of modifiers of integrin function. Our data also provide insights into the molecular mechanism and treatment of arthrogryposis, renal dysfunction, and cholestasis syndrome.

The co-influence of VWD type 2B/2M mutations in the A1 domain and platelet GPIbα on the rate of cleavage to VWF by ADAMTS13

INTRODUCTION

In plasma, the size of the von Willebrand factor (VWF) multimer is down-regulated by ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13). The binding of platelets or glycoprotein (GP) Ibα recombinant fragment to VWF domain A1 may increase the cleavage by ADAMTS13 to VWF. Both type 2B and type 2M von Willebrand disease (VWD) result in bleeding disorders with the diathesis of increased and decreased binding affinity between GPIbα and VWF, respectively. However, the influence of 2B/2M VWD mutations in the A1 domain and GPIbα on cleavage by ADAMTS13 to VWF needs further study.

MATERIALS AND METHODS

Different types of full-length human recombinant VWF (rVWF) were expressed, including three type 2B mutations (P1337L, H1268D, and R1308C), one type 2M mutation (D1302G), and wild type (WT). The three characterized types of rVWF were digested by ADAMTS13 under static conditions or high-shear stress. The interaction of rVWF and ADAMTS13 was also tested by plate-binding assays.

RESULTS

Under static (natured) conditions or high-shear stress, type 2B mutants exhibited a higher susceptibility to ADAMTS13 than rVWF-WT, whereas type 2M mutant was normal. While under static (denatured) conditions or high-shear stress (with GPIbα fragment) rVWF-WT showed an even higher susceptibility to ADAMTS13 than the two type 2B mutants studied.

CONCLUSION

Type 2B mutations localized in the A1 domain could enhance the sensitivity to ADAMTS13-mediated proteolysis. When GPIbα participated, there was a dramatically increased proteolytic cleavage of VWF by ADAMTS13 to rVWF-WT, excluding some type 2B mutants.

Platelet functional alterations in a Bernard-Soulier syndrome patient with filamin A mutation

Defects in filamin A (FLNA) gene could lead to low platelet counts and decreased surface expression of glycoprotein (GP) Ibα. Here, we report and investigate the FLNA genomic alteration of a case with Bernard-Soulier syndrome (BSS), a rare hereditary bleeding disorder caused by quantitative or qualitative abnormalities in the GP Ib-IX-V receptor. DNA sequencing analysis reveals the presence of a GP Ibα c.987G > A mutation and a FLNA c.1582 G > A mutation in this patient. Transient transfection studies show that GP Ibα c.987G > A mutation abolishes the surface expression of GP Ibα on the transfected CHO cells. On the other hand, abnormal responses to collagen, including the platelet aggregation, secretion, and GP VI signaling pathways, are associated with FLNA c.1582G > A mutation. Our findings confirm a central role for FLNA in platelet-adhesive functions. The interaction between FLNA and GP Ibα in platelets deserves to be investigated.

Mutations in the D1 domain of von Willebrand factor impair their propeptide-dependent multimerization, intracellular trafficking and secretion

We identified three novel mutations (p.Gly39Arg, p.Lys157Glu, p.Cys379Gly) and one previously known mutation (p.Asp141Asn) in the von Willebrand factor propeptide from three von Willebrand disease patients. All four mutations impaired multimerization of von Willebrand factor, due to reduced oxidoreductase activity of isomeric propeptide. These mutations resulted in the endothelial reticulum retention and impaired basal and stimulated secretions of von Willebrand factor. Our results support that the mutations in the D1 domain lead to defective multimerization, intracellular trafficking, and secretion of von Willebrand factor and result in bleeding of patients.

Abstract 45: Characterization of a Novel Integrin Binding Protein that is Essential for αIIbβ3 Outside-in Signaling and Hemostasis

Integrins are heterodimeric (α/β) membrane proteins that play fundamental roles in many biological processes, e.g. cell adhesion and spreading, which are important for platelet function and hemostasis. Integrin function is modulated by bi-directional transmembrane signaling: inside-out and outside-in, which is mediated through the interactions between integrin cytoplasmic tails and intracellular, regulatory proteins. Here, we show that VPS33B, a member of the Sec1/Munc18 (SM) family and component of the Class C core of the CORVET/HOPS sorting complexes, binds directly to the β subunit. Overexpression of VPS33B in CHO cells potentiated α IIb β 3 outside-in signaling but not inside-out signaling. Platelets, from megakaryocyte- and platelet-specific VPS33B conditional knockout mice we generated, had normal morphology yet their spreading on fibrinogen was impaired and they failed to support clot retraction. Platelet aggregation and ATP secretion in response to low-dose thrombin were reduced in the VPS33B knockout mice. α IIb β 3 -mediated endocytosis of fibrinogen was also defective. Tail bleeding times were prolonged in the VPS33B knockout mice. Furthermore, VPS33B acted upstream of the RhoA-ROCK-MLC and Rac1 dependent pathways that leads to clot retraction and cell spreading, respectively. Our work demonstrates that vesicular trafficking complexes are a novel class of modifiers of integrin function and in hemostasis. Our data also provide insights into the molecular mechanism and treatment of ARC syndrome.

Assessment of the Diagnostic Value of Plasma Levels, Activities, and Their Ratios of von Willebrand Factor and ADAMTS13 in Patients with Cerebral Infarction

BACKGROUND AND OBJECTIVES

Raised levels of von Willebrand factor (VWF) and reduced levels of a disintegrin and a metalloproteinase with a thrombospondin type I motif, member 13 (ADAMTS13) activity are associated with thrombosis. We aimed to investigate the relationships between plasma levels of VWF and ADAMTS13, their ratios, and the occurrence of cerebral infarction and to understand the roles of VWF and ADAMTS13 in cerebral infarction.

METHODS

Ninety-four patients with cerebral infarction and 103 controls were analyzed. Plasma levels of VWF antigen (VWF: Ag), VWF ristocetin cofactor activity (VWF: Rcof), and VWF collagen binding activity (VWF: CB) were measured by enzyme-linked immunosorbent assay (ELISA). The ADAMTS13 activity (ADAMTS13) was measured with FRETS-VWF73. The relationship between plasma levels and ratios of VWF and ADAMTS13 and the occurrence of cerebral infarction were analyzed.

RESULTS

Patients with cerebral infarction displayed higher VWF: Ag and VWF: Rcof levels and lower ADAMTS13, VWF: CB/VWF: Ag, ADAMTS13/VWF: Ag, and ADAMTS13/VWF: Rcof levels compared to controls (P < .01). The highest quartiles of VWF: Ag (odds ratio [OR] = 5.11, 95% confidence interval [CI], 1.49-17.50) and VWF: Rcof (OR = 5.04, 95% CI, 1.62-15.66) and the lowest quartiles of VWF: CB/VWF: Ag (OR = 5.91, 95% CI, 1.95-17.93), ADAMTS13/VWF: Ag (OR = 9.11, 95% CI, 2.49-33.33), and ADAMTS13/VWF: Rcof (OR = 3.73, 95% CI, 1.39-10.03) are associated with cerebral infarction.

CONCLUSIONS

An association was found between reduced levels of VWF: CB/VWF: Ag, ADAMTS13/VWF: Ag, and ADAMTS13/VWF: Rcof ratios and cerebral infarction. Our data suggest that increased levels of VWF and reduced levels of ADAMTS13 activity may contribute to the pathogenesis of cerebral infarction.

[The clinical studies of 51 patients with thrombotic thrombocytopenic purpura]

OBJECTIVE

To comprehensively analyze the clinical characteristics, treatment strategies and outcome of patients with thrombotic thrombocytopenic purpura (TTP).

METHODS

A retrospective survey of 51 TTP patients confirmed in our database. Relevant statistical analyzes were performed by GraphPad Prism 5 software.

RESULTS

51 cases of patients with acquired TTP were identified as idiopathic TTP. In our study, only 18 cases (35.29%) had typical pentalogy of TTP, where thrombocytopenia (100.00%), microangiopathic hemolytic anemia (92.16%) and neurologic abnormalities (88.24%) were more common than fever (72.55%) and renal abnormalities (70.59%). Plasma ADAMTS13 activity was detected in 37 patients with TTP with ADAMTS13 deficiency confirmed in 31 patients (83.78%). Plasma exchange with response of 72.3% was still the preferred strategy in TTP with individuation. Among 36 survival TTP patients, 8 patients (22.22%) relapsed. 15 patients (29.41%) died in our study. The mean ages of responders and deaths were of (37.5±14.5) and (50.1±18.9) respectively; whereas total bilirubin level of responders and deaths were of (43.3±23.5)μmol/L and (63.7±39.7) μmol/L respectively, the differences were statistically significant. Conversely, body temperature, WBC, HGB, PLT, serum creatinine and LDH showed no significant differences (P>0.05).

CONCLUSION

The diagnosis of TTP was based on comprehensive analysis of clinical manifestations. Plasma ADAMTS13 activity test had a higher clinical practical value. The therapeutic alliance with corticosteroids, immunosuppressive agents and Rituximab significantly improved its outcome. The age and high total bilirubin level at onset were associated with less sensitive to plasmapheresis and poor prognosis.

[Hypofibrinogenemia caused by long-term administration of hemocoagulase: three cases report and literature review]

OBJECTIVE

A first report of 3 patients who developed hypofibrinogenemia due to long-term administration of hemocoagulase.

METHODS

The clinical data of three patients with hypofibrinogenemia due to long-term administration of hemocoagulase were analyzed, and the related literature was reviewed.

RESULTS

Case 1, a two-year old girl, had liver traumatic rupture and then treated with massive transfusion and fibrinogen infusion in addition to intravenous recombinant factor VIIa (two times) and hemocoagulase (2 U/d). The liver wound bleeding was soon stopped. However, her plasma fibrinogen level decreased to 0.12 g/L after continuous administration of hemocoagulase for 18 days. Case 2, a three-year old boy, had liver traumatic rupture and was treated with surgical repair, and then received hemocoagulase (2 U/d). On the 8th day, a large amount of blood was found to exude from abdominal cavity drainage tube and indwelling venous catheter, and his fibrinogen dropped to 0.24 g/L. Case 3 was a 45 year-old man who underwent a total mandibular resection because of malignant tumor, and he was given hemocoagulase (4 U/d). A continuous blood oozing was noted from his operation incision, and his fibrinogen level decreased to 0.25 g/L. All the three patients'plasma fibrinogen levels and coagulation tests returned to normal ranges after discontinuation of hemocoagulase administration and supplement of fibrinogen, and the bleeding stopped in cases 2 and 3.

CONCLUSION

Long-term use of hemocoagulase could induce hypofibrinogenemia and severe bleeding.

Glycoprotein Ibα clustering induces macrophage-mediated platelet clearance in the liver

Many immune thrombocytopenia (ITP) patients, particularly patients with anti-glycoprotein (GP) Ib-IX autoantibodies, do not respond to the conventional treatments such as splenectomy. However, the underlying mechanism remains unclear. Here we found that anti-GPIbα N-terminus antibody AN51, but not other anti-GPIbα antibodies (AK2, HIP1, VM16d, or WM23), induced GPIbα clustering that led to integrin αIIbβ3-dependent platelet aggregation. After intravenous injection, AN51 dose-dependently induced thrombocytopenia in guinea pigs, and the platelets were mainly removed by macrophages in the liver. N-acetyl-D-glucosamine, previously shown to inhibit integrin αMβ2-mediated phagocytosis of refrigerated platelets, dose-dependently inhibited AN51-induced platelet clearance. Furthermore, AN51 but not VM16d, induced rapid platelet clearance in the liver of cynomolgus macaques. Five of 22 chronic ITP patients had anti-GPIbα autoantibodies, and the autoantibodies from four of the five patients competed with AN51 for binding to platelets. These data indicate that GPIbα clustering induced by anti-GPIbα N-terminus antibody causes integrin αIIbβ3-dependent platelet aggregation, phagocytosis, and rapid platelet clearance in the liver. Our findings reveal a novel Fc-independent mechanism underlying the pathogenesis of ITP, and suggest new therapeutic strategies for ITP patients with anti-GPIbα autoantibodies.

[Congenital afibrinogenemia caused by a novel insertion mutation in the FGB gene]

OBJECTIVE

To investigate the genetic defect and its mechanism in a patient with congenital afibrinogenemia.

METHODS

The plasma fibrinogen activity and antigen of the patient was determined using the Clauss method and immuno-nephelometric assay, respectively. Genomic DNA was isolated from peripheral blood of the proband and his related family members. All exons and exon-intron boundaries of the three fibrinogen genes (FGA, FGB, FGG) were amplified by PCR followed by direct sequencing. Thrombin fibrin aggregation curve were detected in the plasma of the patient. Wild-type and mutation type fibrinogen vectors were constructed, and then transfected into COS-7 cells. The wild-type and mutant proteins from the culture media and cell lysates were tested by Western blot and ELISA.

RESULTS

APTT, PT, TT were significantly longer in the proband. Plasma fibrinogen activity and antigen of the patient could not be detected using the Clauss method and immuno-nephelometry, respectively. Gene analysis revealed that a novel homozygous GTTT insertion between nucleotides 2833 and 2834 in FGB exon 2 in the proband. The proband's father, mother, brother and son were heterozygous. The polymerization curves of the patient did not show a lag phase or final turbidity, compared with the normal controls. Western blot analysis showed the lack of complete half-molecules of the fibrinogen molecule and fibrinogen in patient's plasma under non-reducing conditions. It also could not detect the truncated Bβ chain under reducing conditions. Abnormal fibrinogen molecule (molecule weight>340 000) were found in transfected COS-7 cells by Western blot, which indicated that the mutation caused the abnormal intracellular fibrinogen molecule assembly. The fibrinogen band was absent in culture media transfected by the mutation. Fibrinogen levels of mutant fibrinogen were no significant different from those of wild-type fibrinogen in cell lysates by ELISA analysis [(2.47 ± 0.30) μg/ml vs (2.65±0.60) μg/ml, P=0.0889]; However, the levels of the mutant fibrinogen were statistically significant lower than those of wild type fibrinogen in culture media [(0.01 ± 0.01) μg/ml vs (3.80±0.80) μg/ml, P=0.0001].

CONCLUSION

Congenital afibrinogenemia was caused by this frameshift mutation in exon 2 of FGB. This novel mutation impaired fibrinogen assembly and secretion.

Extramedullary relapse of acute leukemia after allogeneic hematopoietic stem cell transplantation: different characteristics between acute myelogenous leukemia and acute lymphoblastic leukemia

Extramedullary relapse (EMR) of acute leukemia (AL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a contributor to post-transplantation mortality and remains poorly understood, especially the different characteristics of EMR in patients with acute myelogenous leukemia (AML) and those with acute lymphoblastic leukemia (ALL). To investigate the incidence, risk factors, and clinical outcomes of EMR for AML and ALL, we performed a retrospective analysis of 362 patients with AL who underwent allo-HSCT at the First affiliated Hospital of Soochow University between January 2001 and March 2012. Compared with patients with AML, those with ALL had a higher incidence of EMR (12.9% versus 4.6%; P = .009). The most common site of EMR was the central nervous system, especially in the ALL group. Multivariate analyses identified the leading risk factors for EMR in the patients with AML as advanced disease status at HSCT, hyperleukocytosis at diagnosis, history of extramedullary leukemia before HSCT, and a total body irradiation-based conditioning regimen, and the top risk factors for EMR in the patients with ALL as hyperleukocytosis at diagnosis, adverse cytogenetics, and transfusion of peripheral blood stem cells. The prognosis for EMR of AL is poor, and treatment options are very limited; however, the estimated 3-year overall survival (OS) was significantly lower in patients with AML compared with those with ALL (0 versus 18.5%; P = .000). The characteristics of post-allo-HSCT EMR differed between the patients with AML and those with ALL, possibly suggesting different pathogenetic mechanisms for EMR of AML and EMR of ALL after allo-HSCT; further investigation is needed.

[Clinical studies of 162 patients with von Willebrand disease]

OBJECTIVE

To analyse the epidemiological feature, clinical characters and therapeutic regimens for von Willebrand disease(VWD).

METHODS

The clinical data and laboratory tests results of 162 VWD patients in our center were analyzed.

RESULTS

There were 76 males and 86 female among these patients with the mean age of 7.2(2.0-41.0) and 20.7(5.0-48.0) years, respectively. 86 patients (53.1%) were identified to be type 1 VWD, 34 patients (21.0%) type 3 VWD and 42 patients (25.9%) type 2 VWD. Among type 2 VWD patients, 33 patients were type 2A, 4 patients type 2M, 5 patients type 2B. Eighty-seven patients (53.7%) had a definite family history of bleeding tendency. The most common and specific bleeding symptoms were easy bruising (61.7%), epistaxis (53.7%), prolonged bleeding after surgery or minor injury (53.1%). Menorrhagia (66.3%) was common in female patients. The analysis of Vicenza bleeding scores in all patients showed that only 56(34.6%) patients had abnormal bleeding scores. FVIII/VWF concentrates and cryoprecipitate were applied to 45 patients (27.8% ), Desmopressin (DDAVP) to 8 patients. Eight female patients need oral contraceptives jointly to control menorrhagia. Hysterectomy had to be performed in 2 female patients with VWD.

CONCLUSION

VWD was a common congenital bleeding disorder with heterogeneous characters, it was necessary to screen, identify, classify accurately this disease in order to supply to effectively individualized treatment.

Specific macrothrombocytopenia/hemolytic anemia associated with sitosterolemia

Sitosterolemia (phytosterolemia) is a rare inherited sterol storage disorder, characterized by significantly elevated plasma levels of plant sterols. The clinical features of sitosterolemia are xanthomas, premature atherosclerosis, arthritis, and, occasionally, liver function impair and hematologic abnormalities. This disorder is caused by mutations of ABCG5/ABCG8 genes. We report here the clinical, laboratory, and molecular genetic features of 13 patients with sitosterolemia from eight unrelated families who had specific hematologic problems of macrothrombocytopenia, hemolytic anemia, and splenomegaly besides the major clinical manifestations. The peripheral blood films showed some unique features: large platelets surrounded by a circle of vacuoles, and various abnormal erythrocyte shapes, especially stomatocyte. According to these distinct changes of blood cell morphology, we identified two sitosterolemia patients who lacked the classical clinical phenomena. All the patients had been misdiagnosed with immune thrombocytopenia (ITP), Evans syndrome, or secondary ITP with delay being 28.8 years between symptom onset and correct diagnosis. These results indicate that sitosterolemia is certainly not as rare as originally thought. The phenomena of macrothrombocytopenia/hemolysis might represent a new platelet disorder. Plasma plant sterols and ABCG5/ABCG8 genes should be analyzed when such hematologic abnormalities are unexplained.