Objective of this study was to identify gene mutation involved in a patient with type 2A von Willebrand disease (vWD). The bleeding time, vWF:Ag, FVIII:C, RIPA and multimeric assay were used for phenotypic diagnosis. All of the 52 exons and the exon-intron boundaries of vWF gene were amplified by polymerase chain reaction (PCR) and direct sequencing was carried out. The results indicated that the levels of vWF:Ag, FVIII:C and RIPA decreased in this patient, the vWF multimer with high and intermediate molecular weight was absent in plasma. The sequencing of genomic DNA revealed a C4738G (L1580V) missense mutation in the vWF gene from the patient. In conclusion, the C4738G (L1580V) missense mutation effecting the form of vWF multimer was responsible to molecular mechanism in this patient with vWD.
Adult ; Humans ; Male ; Mutation, Missense ; von Willebrand Disease, Type 2 ; genetics ; von Willebrand Factor ; analysis ; genetics

OBJECTIVETo detect the plasma activity of von Willebrand factor-cleaving protease (ADAMTS13) in the patients with prothrombotic status, and explore the effect and significance of ADAMTS13 in the prothrombotic status. The correlation of ADAMTS13 with von Willebrand factor (vWF), thrombospondin 1 (TSP1), C-reactive protein etc, and blood pressure was simultaneously analyzed．

METHODSThe activity of ADAMTS13 in patient groups (atherosclerosis, diabetes, acute promyelocytic leukemia, cancer and sepsis, a total of 260 cases) and in control group 50 cases were evaluated by residue collagen binding assay（R-CBA）, the protein levels of TSP1 and vWF were measured by ELISA kits； the correlation of ADAMTS13 activity with CRP, creatinine, and blood pressure was analyzed with statistical soft ware.

RESULTSThe activity of plasma ADAMTS13 in patient group was significantly lower than that in normal control group(P<0.05). And the protein levels of TSP1 and vWF in the patients with prothrombotic status were higher than those in the normal controls(P<0.05). Analysis of the correlation showed that the ADAMTS13 activity correlated negatively with the levels of TSP1 protein, blood sugar, blood pressure, D-dimer, creatinine,and CRP levels (P<0.05), however, the ADAMTS13 activity did not significantly correlate with the levels of serum lipids, blood type, platelet number and hemoglobin level(P>0.05).

CONCLUSIONThe plasma ADAMTS13 activity is decreased in the patients with prothrombotic status, suggesting that the decreased ADAMTS13 activity may participate in the occurrence of prothrombotic status, and the dectection of plasma ADAMTS13 activity may help the diagnosis of pro-thrombotic disease.

ADAMTS13 Protein ; Factor Analysis, Statistical ; Fibrin Fibrinogen Degradation Products ; Humans ; Sepsis ; Thrombosis ; von Willebrand Factor

OBJECTIVETo analyze phenotype and genotype of three Chinese pedigrees with von Willebrand disease (vWD), and explore the molecular mechanism.

METHODSBleeding time (BT), activated partial thromboplastin time (APTT), ristocetin-induced platelet aggregation (RIPA), von Willebrand factor (vWF): ristocetin cofactor (RCof) (vWF:RCof), vWF antigen (vWF:Ag), vWF activity (vWF:A) test, vWF collagen binding assay (vWF:CB), vWF and Factor VIII (FVIII) binding assay (vWF:FVIII:B) and multimer analysis were used for phenotype diagnosis. Genomic DNA was extracted from the peripheral blood (PB). All the 52 exons and flanking sequences of the probands' vWF gene were amplified by PCR and analyzed by direct sequencing.

RESULTSAPTT were prolonged in all three probands, while BT were normal excepting for proband 3. Plasma RIPA, vWF:RCo, vWF:Ag, vWF:A and vWF:CB were decreased in different extents. In multimer analysis, proband 3 lost the large and intermediate molecular weight multimers, while proband 1 and 2 were normal. Gene analysis in the three probands revealed three heterozygous missense mutations of 144067 G→A (R2287Q) in exon 39, 110374G→A (R1374H) and 110770C→T (S1506L) in exon 28 and heterozygous polymorphism 110667G→A (D1472H) in exon 28, respectively.

CONCLUSIONThe three heterozygous mutations (R2287Q, R1374H and S1506L) and an heterozygous polymorphism (D1472H) are genetic defects of the hereditary vWD of the three pedigrees respectively. R2287Q is a novel mutation reported for the first time in the literature.

Adult ; Child ; DNA Mutational Analysis ; Female ; Genotype ; Heterozygote ; Humans ; Male ; Pedigree ; Phenotype ; von Willebrand Diseases ; diagnosis ; genetics ; von Willebrand Factor ; genetics ; metabolism

Type 2N von Willebrand disease (vWD) can be confused with hemophilia A due to decreased factor VIII levels and a bleeding tendency, and differential diagnosis is of importance for providing the optimal treatment and genetic counseling. For the accurate diagnosis of type 2N vWD, von Willebrand Factor (vWF) function tests, multimer assay and gene mutation analysis are needed. The patient was a 38-yr-old Nepalese woman with a history of bleeding manifestations from childhood, such as hemarthrosis, intramuscular hematoma, and menorrhagia. Family history revealed that her mother and elder brothers also had bleeding manifestations from childhood. When she had a laparotomy in 1991, she was diagnosed as hemophilia A with factor VIII level of 3.6% and was transfused with whole blood, factor VIII and cryoprecipitates. In June 2007, she was admitted to our hospital for further evaluation of bleeding tendency. Blood tests revealed normal CBC; bleeding time, 2 min; PT, 14.9 sec (11-14 sec); aPTT, 51.2 sec (24-38 sec); and factor VIII, 4.9% (50-150%). The prolonged aPTT was corrected by 1:1 mixing test to the levels of 106% and 84%, respectively, before and after 2 hr-incubation at 37degrees C. No abnormalities were found in the vWF antigen level (71.3%), ristocetin cofactor assay (130.4%), and multimer assay. Direct DNA sequencing of the VWF gene revealed homozygous missense mutation located in exon 19, c.2446C>T (p.Arg816Trp), confirming the diagnosis of type 2N vWD.
Adult ; Amino Acid Substitution ; Asian Continental Ancestry Group/genetics ; Base Sequence ; Female ; Genotype ; Homozygote ; Humans ; Nepal ; von Willebrand Disease/blood/*diagnosis/genetics ; von Willebrand Factor/analysis/*genetics

This study was purposed to investigate the changes of von Willebrand factor cleaving protease (ADAMTS13) activity and vWF antigen level in patients with acute myelogenous leukemia (AML) before and after treatment and evaluate their clinical significance. Seventy-three AML patients were enrolled in this study, the sodium citrate anticoagulated plasma was collected before and after their induction chemotherapy. Fluorescence resonance energy transfer substrate vWF73 (FRETS-vWF73) assay was established to detect the plasma ADAMTS13 activity while vWF antigen level was measured by ELISA. The results showed that the ADAMTS13 activity in newly diagnosed patients with AML before induction therapy was obviously lower than that in normal controls (63.3 ± 25.5)% vs (105.1 ± 37.7)(P < 0.01), while the vWF antigen level was higher than that in normal controls (226.6 ± 127.0)% vs (111.4 ± 39.7)% (P < 0.01). After standard induction chemotherapy, the ADAMTS13 activity of AML patients in complete remission period was higher than that in AML patients before therapy (P < 0.01), and was not significant difference with that in normal controls; the vWF antigen was significantly lower than that in AML patients before therapy (P < 0.01), but it still was higher than that in controls (P < 0.05). The ADAMTS13 activity in newly diagnosed AML patients complicated with infection before therapy was obviously lower than that in AML patients without infection (52.2 ± 20.6)% vs (73.9 ± 24.7)% (P < 0.01), while the vWF antigen level was significantly higher than that in AML patients without infection (262.2 ± 135.7)% vs (193.8 ± 110.2)% (P < 0.05). The ADAMTS13 activity in AML patients with disseminated intravascular coagulation (DIC) was significantly lower than that in AML patients without DIC (42.0 ± 14.5)% vs (73.4 ± 22.7)% (P < 0.01), while the vWF antigen level was obviously higher that in AML patients without DIC (274.2 ± 140.0)% vs (204.7 ± 115.5)% (P < 0.01). It is concluded that the ADAMTS13 activity in newly diagnosed AML patients befor induction therapy has been confiremed to be lower and the vWF antigen level to be higher, especially in AML patients with infection or DIC. The ADAMTS13 and vWF antigen may play a role in the pathogenesis of AML and the formation of infection and DIC.
ADAM Proteins ; blood ; ADAMTS13 Protein ; Disseminated Intravascular Coagulation ; Humans ; Leukemia, Myeloid, Acute ; blood ; von Willebrand Factor ; analysis

BACKGROUND: We intended to find the mutations of von Willebrand factor (VWF) gene as the most important contributing factor of von Willebrand disease (VWD) in Korean patients. METHODS: In 40 known vWD patients mutations of vWF gene were sought by direct sequencing of PCR products targeting exons 18, 19, 20, 26, 28 and 52 frequently implicated as the locations of mutation. For factors other than VWF gene contributing to VWD phenotype, we tested ABO blood group and measured ADAMTS13 activity in VWD patients. RESULTS: Twenty-seven cases (67.5%) were type 1 vWD, 3 cases (7.5%) type 3, and 5 cases (12.5%) type 2A. Three cases were type 2A or 2B (7.5%) and 2 cases were suspected to be type 2N (5.0%). Among them six candidate missense mutations were found: V1279I, R1306W, R1308C, and V1316M were previously reported in type 2B and type 1 vWD, and C858W and T1477I were novel findings. All patients were heterozygotes. Blood group O was overly represented in VWD patients, while ADAMTS13 activity of the patients was not significantly different from that of normal control. CONCLUSIONS: Mutation of VWF gene detected by genetic studies can significantly improve the diagnostic accuracy, especially in subtype assignment of VWD. Two novel mutations, C858W and T1477I associated with VWD were found and expected to contribute to the elucidation of its pathophysiology.
ABO Blood-Group System ; ADAM Proteins/analysis ; Heterozygote ; Humans ; Korea ; *Mutation, Missense ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Sequence Analysis, DNA ; von Willebrand Disease/classification/diagnosis/*genetics ; von Willebrand Factor/analysis/*genetics

The aim of current study was to detect intron 22 inversion of factor VIII gene in severe hemophilia A (HA) patients and screen the carriers of the gene inversion. Fifty-five cases of severe HA were involved and factor VIII gene inversion was detected and identified by long distance-PCR (LD-PCR) and 0.6% agarose gel electrophoresis. The 11 kb and 12 kb bands indicate the factor VIII gene inversion and non-inversion, respectively. Occurring of both 11 kb and 12 kb bands indicates a carrier of the inversion. The results showed that factor VIII gene inversion existed in 22 out of 55 cases, which accounted for about 40% of total detected patients. Five carriers of factor VIII gene inversion were diagnosed from the members in 15 families. In conclusion, LD-PCR assay is a simple, rapid and accurate method for detection of factor VIII gene inversion, and this approach is helpful in screening, carrier testing, and prenatal diagnosis of severe hemophilia A.
Adolescent ; Adult ; Antigens ; analysis ; Child ; Child, Preschool ; Chromosome Inversion ; Factor VIII ; genetics ; Hemophilia A ; blood ; genetics ; Humans ; Infant ; Male ; Polymerase Chain Reaction ; methods ; von Willebrand Factor ; immunology

OBJECTIVETo investigate the changes in plasma levels of atrial natriuretic peptide (ANP), endothelin-1 (ET-1) and von Willebrand factor (vWF), and their significance among newborns with persistent pulmonary hypertension (PPH).

METHODSSixty-six newborns with PPH (case group) (mild: 26 cases; moderate: 21 cases; severe: 19 cases), as well as 40 newborns without PPH (control group) who were hospitalized in the same period, were enrolled. The control group underwent echocardiography on admission. The case group underwent echocardiography before treatment (with refractory hypoxemia) and after 7 days of treatment for measurement of pulmonary artery systolic pressure (PASP). Meanwhile, plasma levels of ANP, ET-1 and vWF were measured using ELISA.

RESULTSBefore treatment, the case group had significantly higher plasma levels of ANP, ET-1 and vWF than the control group (P<0.05), and these indices increased as PASP rose. After 7 days of treatment, the children with mild or moderate PPH showed normal PASP, and their plasma levels of ANP, ET-1 and vWF were not significantly different from those of control group. The children with severe PPH had significant decreases in all indices, but they were significantly higher than those of the control group. Plasma levels of ANP, ET-1 and vWF were significantly positively correlated with PASP before and after treatment (P<0.01).

CONCLUSIONSChanges in plasma levels of ANP, ET-1 and vWF can reflect PASP in newborns with PPH during treatment. Dynamic monitoring of these indices can help to judge the severity of PPH and guide treatment.

Atrial Natriuretic Factor ; blood ; Endothelin-1 ; blood ; Humans ; Infant, Newborn ; Persistent Fetal Circulation Syndrome ; blood ; physiopathology ; Pulmonary Artery ; physiopathology ; Systole ; von Willebrand Factor ; analysis

To study the mechanism of thrombogenesis and search new anti-thrombotic agent, the cDNA for human vWF A1 domain was high-level expressed in E. coli and recombinant protein of vWF A1 with biologic activity was obtained. The gene encoding A1 domain was amplified by PCR from plasmid containing full length cDNA of human vWF. After confirming by DNA sequencing analysis, the recombinant expression plasmid pQE31-vWF/A1 was constructed and introduced into E. coli M15 strain, then induced by IPTG; the expressed protein was purified with Ni-NTA agarose, identified by Western blotting. The results showed that the 854 bp DNA fragment was obtained by PCR from the plasmid containing full length cDNA for human vWF and its sequence was identical to the published sequence. High level expression of A1 protein was yielded after 5 hour-induction, which amounted to 30% of total bacteria protein in inclusion body. Western blot demonstrated it possessed good antigenicity and high specificity. It is concluded that cDNA for vWF/A1 had been cloned successfully, high level expression of A1 protein was achieved in E. oli. This study will provide a basis for the further clinical and basic research on the role of vWF in thrombosis and hemostasis.
Blotting, Western ; Cloning, Molecular ; DNA, Complementary ; chemistry ; Escherichia coli ; genetics ; Humans ; Polymerase Chain Reaction ; Recombinant Proteins ; analysis ; von Willebrand Factor ; analysis ; biosynthesis ; genetics

This study was purposed to investigate the change of early hemostatic function in patients with myeloproliferative diseases (MPD) and to explore its significance in combination with clinical data. The platelet aggregative function was measured by using ristomycin, adenosine diphosphate, collagen and adrenine as inductors, the plasma von Willebrand factor-associated antigen (vWF: Ag) level was measured by enzyme-linked immunosorbent assay (ELISA), the plasma von Wellebrand factor-ristomycin cofactor (vWF: Rco) activity was measured in 6 patients with obviously low ristomycin induced platelet aggregation (RIPA). The results showed that the platelet aggregative function obviously decreased in 35 patients, there were distinct differences in maximal platelet aggregative rate between patients and normal controls induced by 4 inductors respectively (P < 0.001, P < 0.001, P = 0.002, P < 0.001). There was no obvious difference between patients with MPD and healthy controls in plasma vWF: Ag level (P > 0.50). Plasma vWF: Rco activity in all 6 patients with MPD chosen was in the normal range, except one patient with essential thrombocytosis (ET) whose plasma vWF: Rco activity was much lower than normal. No correlation was found between platelet count and plasma vWF: Ag level in the patients (r = -0.180). No correlation was found between platelet count and maximal platelet aggregative rate induced by 4 inductors respectively in patients. It is concluded that the occurrence of abnormal platelet aggregative function is high in patients with MPD. The RIPA and vWF: Rco activity decrease in one patient with ET. However, the shortage of vWF polymer existed in his plasma have needs for further research. No correlation was observed between hemostasis and clinical manifestations. However, because of the high occurrence of platelet dysfunction in MPD patients, the clinical application of anti-platelet drugs should be considered carefully.
Adolescent ; Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Myeloproliferative Disorders ; blood ; physiopathology ; Platelet Aggregation ; Platelet Function Tests ; von Willebrand Factor ; analysis