Analysis of the effects of low/intermediate dose of coagulation factor Ⅷ on 30 adult patients with severe hemophilia A in a single center / 中华血液学杂志

Objective: To evaluate the clinical effects of low- and intermediate-dose factor Ⅷ (F Ⅷ) prophylaxis in Chinese adult patients with severe hemophilia A. Methods: Thirty adult patients with severe hemophilia A who received low- (n=20) /intermediate-dose (n=10) F Ⅷ prophylaxis at Nanjing Drum Tower Hospital affiliated with Nanjing University Medical College were included in the study. The annual bleeding rate (ABR), annual joint bleeding rate (AJBR), number of target joints, functional independence score of hemophilia (FISH), quality of life score, and health status score (SF-36) before and after preventive treatment were retrospectively analyzed and compared. Results: The median follow-up was 48 months. Compared with on-demand treatment, low- and intermediate-dose prophylaxis significantly reduced ABR, AJBR, and the number of target joints (P<0.05) ; the improvement in the intermediate-dose prophylaxis group was better than that in the low-dose prophylaxis group (P<0.05). Compared with on-demand treatment, the FISH score, quality of life score, and SF-36 score significantly improved in both groups (P<0.05), but there was no significant difference between the two groups (P>0.05) . Conclusion: In Chinese adults with severe hemophilia A, low- and intermediate-dose prophylaxis can significantly reduce bleeding frequency, delay the progression of joint lesions, and improve the quality of life of patients as compared with on-demand treatment. The improvement in clinical bleeding was better with intermediate-dose prophylaxis than low-dose prophylaxis.

Molecular mechanisms of protein C deficiency caused by C64W and F139V mutations / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the molecular mechanisms of protein C (PC) deficiency caused by PC gene mutations of C64W, F139V and K150 deletion (K150d).</p><p><b>METHODS</b>Wild-type and mutant PC cDNA expression plasmids (PCwt, PC C64W, PC F139V, PC K150d) were constructed and transfected into COS-7 cells or CHO cells respectively for in vitro expression study and immunofluorescent assay. Fluorescent real-time PCR was used to detect the expression of PC mRNA, protein degradation inhibition and endo-beta-N-acetylglucosaminidase H (Endo H) digestion experiments to explain the mutant protein degradation pathway and its localizations inside the cells.</p><p><b>RESULTS</b>PC C64W was not secreted from the cells and was gradually degraded inside the cells. There was partial secretion of PC F139V, most of the protein molecule was not secreted and degraded intracellularly. Mutant PC K150d was secreted normally from the cells. Fluorescent realtime PCR analysis of total mRNA from transfected cells showed no reduction of the mutant PC mRNA expression compared with that of wild-type PC mRNA. Protein degradation inhibition experiments showed that mutants PC C64W and PC F139V were degraded intracellularly through the proteasome pathway. Endo H digestion experiments and immunofluorescence results suggested that mutant PC molecules were located mainly in pre-Golgi apparatus.</p><p><b>CONCLUSIONS</b>Impaired secretion and degradation intracellularly of the mutants might be the molecular mechanisms of PC deficiency caused by C64W and F139V mutations. K150 deletion mutation might not affect the secretion of the mutant.</p>

Analysis of phenotype and genotype in two Chinese pedigrees with hereditary protein C deficiency / 中华血液学杂志

<p><b>OBJECTIVE</b>To identify the phenotype and gene mutation in two Chinese pedigrees with hereditary protein C deficiency.</p><p><b>METHODS</b>The plasma level of protein C activity (PC: A) , protein C antigen (PC: Ag), protein S activity (PS: A), and antithrombin activity (AT: A) of the probands and their family members were detected using chromogenic assay and ELISA, respectively. All of the nine exons and intron-exon boundaries of protein C gene were amplified by PCR and analyzed by direct sequencing of the probands. Restriction enzyme site analysis was used to confirm the mutation.</p><p><b>RESULTS</b>The plasma PC: A and PC: Ag for proband 1 was 1.2% and 0, respectively. Compound heterozygous mutations, C(TGC)64W (TGG) and F(TTC) 139V(GTC) , were identified in her, the former being inherited from the maternal side and the later the paternal side. Further genetic analysis showed that her husband ( II 8) had the heterozygous deletion mutation (K150 or 151 Del) in exon 7, her daughter had the same heterozygous deletion mutation and a F139V. The plasma PC: A and PC: Ag for proband 2 was 50. 3% and 1.9 mg/L, respectively. He had the heterozygous Lys150 or Lys151 deletion mutation, which was inherited from his father. Polymorphisms of C/T at position - 1654, A/G at - 1641 , and A/T at - 1476A/T in the promoter region of protein C were confirmed in all members of the two pedigrees, of which, proband 2 had homozygous CC/GG/TT. The F139V mutation was confirmed by restriction enzyme site analysis and polymorphism for this mutation was excluded. PS: A and AT: A were in normal range for all members.</p><p><b>CONCLUSION</b>Compound heterozygous mutation C64W and F139V of protein C gene lead to type I hereditary protein C deficiency for proband 1. K150 or 151 deletion mutation and polymorphism of CC/GG/TT might lead to type I hereditary protein C deficiency for proband 2. C64W is a novel mutation for protein C gene. F139V and K150 or 151 deletion mutation are reported for the first time in China.</p>

A novel mutation in antithrombin gene results in hereditary antithrombin deficiency / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the antithrombin (AT) activity (AT: A) and AT antigen (AT: Ag) level in a Chinese family with type I antithrombin (AT) deficiency, and to explore the molecular mechanism of AT deficiency.</p><p><b>METHODS</b>Immuno-nephelometry and chromogenic assay were used to detect the plasma level of AT: A and AT: Ag, respectively. Genomic DNA was isolated from the peripheral blood, and all the seven exons and exon-intron boundaries of AT gene were amplified by PCR and direct sequencing.</p><p><b>RESULTS</b>The plasma levels of AT: A and AT: Ag of the proband were 45% and 97 mg/L, respectively, which led to a type I AT deficiency. A heterozygous T to A mutation was found at nucleotide 9833 in exon 5 resulting in a Tyr363Stop nonsense mutation. The sequencing results from the pedigree indicated that four other members also had this mutation.</p><p><b>CONCLUSION</b>This heterozygous nonsense mutation of T9833A in exon 5 resulting in venous thrombosis is a novel genetic defect of hereditary AT deficiency, which has not been described before.</p>

Antithrombotic mechanisms of holothurian glycosaminoglycan extracted from sea cucumber / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the antithrombotic mechanisms of holothurian glycosaminoglycan (GAG) extracted from sea cucumber.</p><p><b>METHODS</b>Human endothelial cell line EA. hy926 cells were treated with 10 mg/L GAG or 10U/mL unfractionated heparin (UFH) by short-term (15 min - 2 h) and longer-time incubation (6 h - 48 h). Different doses of GAG were used to stimulate EA. hy926. Released free tissue factor pathway inhibitor(TFPI) was determined by ELISA assay. TFPI expression was investigated by immunofluorescent method and TFPI mRNA level by real-time PCR. In a 96-wells microtitre plate, pooled normal plasma containing different concentrations of GAG was allowed to clot by addition of thrombin and calcium chloride, fibrinolysis was induced by addition of t-PA. TRR (TAFI-related retardation of clot lysis) was used to assess thrombin-activatable fibrinolysis inhibitor(TAFI) functional activity.</p><p><b>RESULTS</b>GAG increased TFPI synthesis, expression and secretion in a dose- and time dependent manner. GAG at low concentrations could lengthen while at intermediate concentrations could shorten clot lysis times significantly as compared to control values. TRR was dose-dependently decreased on addition of GAG.</p><p><b>CONCLUSIONS</b>GAG increases TFPI synthesis, expression and secretion of endothelial cells. GAG at intermediate concentrations significantly affects clot stability of a developing clot by means of diminishing TAFI activation.</p>

A heterozygous point mutation G13328A in antithrombin gene causes thrombosis / 中华血液学杂志

<p><b>OBJECTIVE</b>To identify the phenotype and the gene mutation in a kindred with antithrombin (AT) deficiency.</p><p><b>METHODS</b>Immuno-nephelometry and chromogenic assay were used to detect the plasma level of AT antigen (AT: Ag) and activity (AT: A), respectively. All the seven exons and intron-exon boundaries of AT gene from the propositus were amplified by PCR and direct sequencing of the PCR pro-ducts was performed. Corresponding PCR fragments from the kindred were also sequenced directly. Megaprimer method was used to construct the mutant AT cDNA expressing vector from normal plasmid pCRII AT cDNA. The normal and mutant AT plasmid were transiently transfected into Cos-7 cells and AT: Ag was detected in supernatant and lysate of transfected cell with ELISA.</p><p><b>RESULTS</b>The plasma level of AT: Ag and AT: A for the propositus were 179 mg/L and 42.3%, respectively. A heterozygous G13328A missense mutation in exon 6 was identified, which led to the substitution of Thr (ACC) 404 for Ala (GCC). The sequencing results from the pedigree suggested that three other members also had the mutation. The level of AT:Ag in supernatant and lysate from cells transfected with mutant AT cDNA was 40% and 68% of that of normal AT cDNA transfected cells.</p><p><b>CONCLUSION</b>This is an unreported AT gene mutation in China, which causes type I hereditary antithrombin deficiency and thrombosis in the proposita.</p>

Study on the molecular mechanism of antithrombin gene C2759T (Leu99Phe) mutation causing antithrombin deficiency / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the molecular mechanism of antithrombin (AT) gene C2759T (Leu99Phe) mutation causing AT deficiency.</p><p><b>METHODS</b>A mutated AT cDNA expression plasmid ATM2759 was constructed by mega-primer method. ATM2759 and wild type AT cDNA expression plasmid ATN were transfected into COS7 cells or CHO cells by using Superfect reagent respectively for in vitro expression study and immunofluorescence assay.</p><p><b>RESULTS</b>The antigen levels of AT (AT:Ag) in the cell lysate of ATM2759 transfected COS7 cells and the cell culture supernatant were 174.97% and 35.63% of that of ATN transfected COS7 cells respectively, whereas the AT activity in the cell culture supernatant was 47.73% of the control's. Immunofluorescence analysis showed that the fluorescence intensity was significantly higher in ATM2759 transfected CHO cells than in those transfected with ATN.</p><p><b>CONCLUSIONS</b>Leu99Phe substitution may not affect the binding capacity of AT with heparin. Secretion defect and intracellular accumulation of the mutated AT protein might be the mechanisms of this mutation causing AT deficiency.</p>

The inherited coagulation factor XI deficiency caused by intronic mutation IVS J-4delgttg / 中华血液学杂志

<p><b>OBJECTIVE</b>To identify gene defect in a Chinese pedigree of hereditary coagulation factor XI (FXI) deficiency.</p><p><b>METHODS</b>The peripheral blood samples were collected from the proband and her family members. The plasma PT, APTT, FXI:C and FXI:Ag were assayed. The FXI gene exons and exon-intron boundaries of the proband were amplified by PCR and then sequenced directly. The mRNA of FXI in the peripheral blood was analyzed with RT-PCR.</p><p><b>RESULTS</b>The proband and some of her family members had prolonged APTT. The plasma FXI:C and FXI:Ag of the proband, her brother and her parents were lower than 10% and 50% of the normal values, respectively. Nucleotide sequence analysis revealed that the proband and her brother had a homozygous mutation of IVS J-4delgttg in FXI gene. The mutation was inherited from her parents who were heterozygotes. The mutation was not found in 60 normal subjects. No FXI mRNA was detected in peripheral blood sample of the proband.</p><p><b>CONCLUSION</b>The IVS J-4delgttg is a novel mutation causing FXI deficiency, which may interfere with mRNA splicing.</p>

Fibrinogen beta chain gene mutation contributes to one congenital afibrinogenemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To identify the fibrinogen (Fg) gene mutations in a Chinese pedigree of congenital afibrinogenemia.</p><p><b>METHODS</b>The plasma Fg activity and protein of the proband and his family members were detected. Genomic DNA was isolated from the peripheral blood mononuclear cells. All the exons and exon-intron boundaries of fibrinogen gene were amplified by PCR and sequenced thereafter.</p><p><b>RESULTS</b>Two mutations, 7972 del G in FGB and T2543A in FGG, were found in the proband.</p><p><b>CONCLUSIONS</b>FGG2543 is a polymorphism site, which lead to the polymorphism of gamma144 I/K. The G deletion at base 7972 of FGB contributes to the frameshift mutation after amino acid 419, resulting in the truncated beta chain without the terminal 27 amino acids. The latter may contributes to the pathogenetic mechanisms in Chinese congenital afibrinogenemia patients. The G deletion at base 7972 of FGB is identified for the first time.</p>

Severe hereditary coagulation factor V deficiency caused by two novel heterozygous mutations / 中华血液学杂志

<p><b>OBJECTIVE</b>To identify gene mutations of a pedigree with inherited factor V (FV) deficiency.</p><p><b>METHODS</b>The activated partial thromboplastin time (APTT), prothrombin time (PT), FV activity (FV:C) and FV antigen (FV:Ag) tests were performed for phenotypic diagnosis. The genomic DNA was extracted from the peripheral blood of the proband and all the 25 exons and their flanks of FV gene were amplified by polymerase chain reaction (PCR). The PCR products were screened by direct sequencing and the mutations were further confirmed by restriction enzyme digestion.</p><p><b>RESULTS</b>APTT, PT, TT, FV:C, FV:Ag of the proband were 249.2 s, 46.6 s, 17.9 s, 0.1% and 1.5%, respectively. FII, FVII, FVIII, FIX, FX activities, vWF and Fg were within normal ranges. Taking the GenBank Z99572 sequence as the reference, four mutations were identified in FV gene of the proband. They were a heterozygous two bases deletion in exon 13 (2238 approximately 2239delAG) introducing a frameshift and a premature stop at codon 689, and a heterozygous missense mutation in exon 23 (G6410T) resulting in the substitution of Gly for Val at codon 2079, respectively. The proband's father and mother were heterozygous for G6410T and for 2238 approximately 2239delAG, respectively.</p><p><b>CONCLUSION</b>The severe FV deficiency of the proband is caused by a frameshift mutation of 2238 approximately 2239delAG and a missense mutation of G6410T, which haven't been identified before.</p>

Inherited afibrinogenemia caused by compound heterozygous mutations in the beta beta-chain of fibrinogen / 中国实验血液学杂志

Congenital afibrinogenemia is a rare autosomal recessive disorder, characterized by the complete absence or extremely reduced level of fibrinogen. To analyze the phenotype and genotype of a family with inherited afibrinogenemia, laboratory studies including activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) were tested in the proband and 9 family members. Fibrinogen (Fg) in plasma were measured by both functional and immunoturbidimetry assay. All the exons, exon-intron boundaries and promoter regions of three Fg genes were analyzed by direct sequencing. 102 healthy blood donors were used as normal control. The results showed that phenotype of the proband was diagnosed as afibrinogenemia. Compound heterozygous mutations in Fg FGB gene were detected in the proband. One was a nonsense mutation (Arg17stop) in exon 2, traced back to the proband's mother. The other was a missense mutation (Gly347Arg) in exon 7, which was from the proband' s father. It is concluded that afibrinogenemia is caused by the compound heterozygous mutations Arg17stop and Gly347Arg in the Beta beta-chain of fibrinogen.

Hereditary hemorrhagic telangiectasia resulted from a nonsense mutation Arg479 Stop in the ALK-1 gene / 中华血液学杂志

<p><b>OBJECTIVE</b>To identify the gene mutations in a pedigree with hereditary hemorrhagic telangiectasia.</p><p><b>METHODS</b>Genomic DNA was extracted from the peripheral blood of the propositus. All of the exons, intron/exon boundaries and the 5' untranslation regions (UTR) of the ALK-1 and endoglin gene were amplified by polymerase chain reaction (PCR). The PCR products were screened by direct sequencing.</p><p><b>RESULTS</b>The mutation is a C1437T substitution in exon 10 of the ALK-1 gene, resulting in Arg 479 Stop.</p><p><b>CONCLUSION</b>The hereditary hemorrhagic telangiectasia propositus is caused by a heterozygous Arg 479 Stop mutation in the ALK-1 gene which has not been identified previously.</p>

Inherited coagulation factor X deficiency caused by two novel mutations in factor X gene / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the molecular mechanisms involved in a pedigree with inherited coagulation factor X (FX) deficiency.</p><p><b>METHODS</b>The activated partial thromboplastin time (APTT), prothrombin time (PT), FX activity (FX:C) and FX antigen (FX:Ag) test were adopted for phenotype diagnosis. All the 8 exons, intron/exon boundaries and the 5'untranslated regions (UTR) of the FX gene were amplified by polymerase chain reaction (PCR) from the genomic DNA extracted from the peripheral blood of the propositus. The PCR products were screened by direct sequencing. The mutation was confirmed by allele specific PCR (ASPCR).</p><p><b>RESULTS</b>The phenotype of the propositus was identified as FX deficiency (type II). Two novel FX gene mutations were detected in the propositus: one was a donor site splice mutation in intron 1 (IVS1 + 1G-->A), another was a missense mutation 1185G-->A in exon 8 (Arg347His).</p><p><b>CONCLUSION</b>The FX deficiency of the propositus is caused by double heterozygous mutations IVS1 + 1G-->A and Arg347His.</p>

FXI gene mutations in two pedigrees of congenital clotting factor XI deficiency / 中华血液学杂志

<p><b>OBJECTIVES</b>To identify the FXI gene mutations in two Chinese pedigrees of congenital factor XI deficiency.</p><p><b>METHODS</b>The peripheral blood samples were collected from the probands and their family members and the plasma FXI:C and FXI:Ag were determined. All the exons and exon-intron boundries of FXI gene were amplified with PCR and sequenced thereafter.</p><p><b>RESULTS</b>A nonsense mutation Trp228stop and two missense mutations Glu323Lys and Leu172Pro were disclosed in the two pedigrees. All mutations existed in a heterozygous state.</p><p><b>CONCLUSION</b>The FXI gene mutations Trp228stop, Glu323Lys and Leu172Pro attribute to the pathogenesis of the congenital factor XI deficiency in Chinese. The Leu172Pro is identified for the first time.</p>

Biochemical activity and gene analysis of inherited protein C and antithrombin deficiency in two Chinese pedigrees / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>We identified the gene mutations in two Chinese pedigree of type I hereditary protein C deficiency and type I hereditary antithrombin deficiency.</p><p><b>METHODS</b>The plasma level of protein C activity (PC:A), protein C antigen (PC:Ag), protein S activity, antithrombin activity (AT:A) and antithrombin antigen (AT:Ag) of propositi and two family members were detected using ELISA and chromogenic assay, respectively. All exons and intron-exon boundaries of protein C gene and antithrombin gene were analyzed by direct sequencing of the corresponding amplified PCR products in DNA from the propositus.</p><p><b>RESULTS</b>The plasma PC:A and PC:Ag of propositus 1 was 26% and 1.43 mg/dl, respectively. The PC:Ag and PC:A of his father were normal. The decreased PC:A level was seen in his mother and 4 of his maternal pedigree. PS:A and AT:A were all normal in pedigree 1 members. A C5498T heterozygous mutation in exon 3 of protein C gene, resulting in the substitution of Arg for Trp at the 15th amino acid, was identified in propositus 1 and 8 of his relatives. The plasma AT:A and AT:Ag of propositus 2 was 48.6% and 10.4 mg/dl, respectively. The reduced AT:A and AT:Ag levels were found in his father and 5 of paternal pedigree. PC:A, PC:Ag and PS:A were all in normal range. A heterozygous 13387-9G deletion in exon 6 of antithrombin gene was identified in propositus 2. This mutation introduced a frameshift and a premature stop at codon 426 and existed in 6 members of pedigree 2.</p><p><b>CONCLUSION</b>The C5498T heterozygous mutation in exon 3 of protein C gene, first reported in China, leads to type I hereditary protein C deficiency. The 13387-9G deletion, a novel mutation, can cause antithrombin deficiency and thrombosis.</p>

Prothrombin deficiency resulted from a homozygous Glu29 to Gly mutation in the prothrombin gene / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the gene mutations in a pedigree with inherited prothrombin (FII) deficiency.</p><p><b>METHODS</b>The activated partial thromboplastin time (APTT), prothrombin time (PT), FII activity (FII:C) and FII antigen (FII:Ag) test were used for phenotype diagnosis. The genomic DNA was extracted from the peripheral blood of the propositus. All the 14 exons, intron/exon boundaries and the 5' and 3' untranslated regions (UTR) of the prothrombin gene were amplified by polymerase chain reaction (PCR). The PCR products were screened by direct sequencing and the mutations detected were further confirmed by restricted enzyme digestion. One hundred and three healthy blood donors were used as controls.</p><p><b>RESULTS</b>The phenotype of the propositus was prothrombin deficiency (type I). With reference to the prothrombin nucleotide sequence published by Degen & Dacie, three variations were found in the FII gene of the propositus. Among them, the novel mutation was a homozygous A601G subtitution in exon 2.</p><p><b>CONCLUSION</b>The prothrombin deficiency of the propositus is caused by a homozygous Glu29 to Gly mutation in the prothrombin gene.</p>