A Novel Missense Mutation in Two Families with Congenital Plasminogen Deficiency: Identification of an Ala675 to Thr675 Substitution

We used a polymerase chain reaction (PCR) strategy and restriction fragment polymorphism analysis to evaluate all 19 exons of the plasminogen (PLG) gene in a Japanese patient with congenital PLG deficiency and her family members (family C). Sequence analysis following amplification of each exon and its flanking regions showed a single G to A transition in exon 17, resulting in the conversion of an Ala675 codon (GCT) to Thr675 codon (ACT). Since this mutation generates a new Mae III site, the Mae III digestion patterns of the PCR-amplified exon 17 fragments from each family member were analyzed. In all cases, the patterns correlated with the activities and antigen levels of plasma PLG in those members. The identical G to A transition in the same codon of exon 17 was detected by a Mae III digestion experiment in another proband and her family members with congenital PLG deficiency (family K). Furthermore, 20 normal individuals examined had no Mae III restriction site at this location. We conclude that a G to A transition in exon 17 is responsible for the congenital PLG deficiency inherited in these two Japanese families.

Protein S Tokushima: An Abnormal Protein S Found in a Japanese Family with Thrombosis

An abnormal protein S (PS) was found in a Japanese family with a high incidence of thrombosis. The proband is a woman who was born in Tokushima Prefecture. She had superior sagittal sinus thrombosis, thrombophlebitis of the left leg, and thrombosis of the placenta. She had a normal plasma level of free PS antigen but decreased PS activity. Her mother and aunt also had thrombophlebitis of the leg, and together with four other family members also showed a normal level but decreased activity of PS. This suggests that hereditary dysfunction of PS is inherited in this family as an autosomal dominant trait. The proband’s PS appears to have a slightly higher molecular weight than normal PS both in the intact and modified form, suggesting that it has a molecular defect on the carboxyl-terminal side of the thrombin-sensitive site. This abnormal PS with apparently unique characteristics was named PS Tokushima.

Type I Congenital Plasminogen Deficiency Is not a Risk Factor for Thrombosis

The risk of thrombosis in type I congenital plasminogen (PLG) deficiency has been suggested, but is still not confirmed. We studied 40 members of two unrelated families with this disease, and found that 21 were heterozygotes of type I congenital PLG deficiency. Three of them had thrombosis, but the other 18 had no thrombosis. The percentages of family members with no history of thrombosis up to a given age among subjects with type I congenital PLG deficiency and healthy controls were analyzed by the Kaplan-Meier method. No significant difference between the two groups was observed by the generalized Wilcoxon test (p = 0.23). These results suggest that there is no significant correlation between type I congenital PLG deficiency and thrombosis.

Molecular mechanism of type I congenital heparin cofactor (HC) II deficiency caused by a missense mutation at reactive P2 site: HC II Tokushima

We found a 66-year-old Japanese patient with type I congenital heparin cofactor (HC) II deficiency manifesting multiple atherosclerotic lesions. To investigate the molecular pathogenesis of our patient, we performed sequencing analysis and expressed recombinant human wild-type and mutant HC II molecules in COS-1 and CHO-K1 cells. Sequencing analysis following amplification of each of all 5 exons and its flanking region showed a single C to T transition at nucleotide position 12,854 in exon 5, which changed a Pro443 codon (CCG) to Leu codon (CTG). Because this mutation generates a new Bhv I site, the Bbv I digestion pattern of the PCR-amplified exon 5 fragments from each family member was analyzed. In all cases, the patterns were consistent with the activities and antigen levels of plasma HC I1 in those members. Transient transfection, metabolic labeling and pulse-chase experiments followed by immunoprecipitation analysis showed that the recombinant mutant HC II molecules were secreted from COS-1 cells in reduced amounts compared with the wild-type, and that an enhanced intracellular association of the mutant molecules with a chaperone, GRP78/BiP, was observed in CHO-K1 cells. Northern blot analysis indicated that the mutant HC I1 mRNA was transcribed at a similar level as that of wild-type. Immunohistochemical staining of the transfected cells revealed that COS-1 cells expressing the mutant HC II molecules were stained mainly in the perinuclear area. We conclude that the impaired secretion of the mutant HC II molecules, due to intracellular degradation, is the molecular pathogenesis of type I congenital HC II deficiency caused by a Pro443 to Leu mutation at reactive P2 site.

Histidine-rich glycoprotein (HRG) Tokushima 2: novel HRG deficiency, molecular and cellular characterization

The proband, a 76-year-old woman, suffered from dural arteriovenous fistula. Her plasma histidine-rich glycoprotein (HRG) level was 50% of the normal level. A low level of plasma HRG was also found in her third daughter. A single nucleotide substitution of T to C was found at nucleotide position 11,438 in exon 6 of the HRG gene from the proband, converting Cys223 to Arg in the second cystatin-like domain. The same mutation was also identified in her third daughter, but not in the other four family members having normal HRG levels or in 50 unrelated healthy Japanese individuals. Expression studies in BHK cells showed that substantial intracellular degradation of the mutant occurred and only about 40% of the recombinant HRG mutant was secreted. These results indicate that congenital HRG deficiency caused by a substitution of Cys223 to Arg is hereditary in this family.

A patient with cyclic neutropenia complicated by severe persistent neutropenia successfully delivered a healthy baby

We describe a 24-year-old pregnant woman complicated by cyclic neutropenia (CN), who was successfully treated with granulocyte-colony stimulating factor (G-CSF). Her white blood cell (WBC) and neutrophil count fluctuated from 2,600 to 4,600/microl, and 26 to 2,530/microl, respectively. The peak neutrophil count gradually decreased as pregnancy advanced, resulting in the disappearance of its cyclicity. At 39 weeks of pregnancy when the neutrophil count became 84/microl, the patient was started on G-CSF and her neutrophil count increased to 1,550/microl on the fourth day after delivery. She delivered a healthy baby without any complications at 39 weeks of pregnancy.

No increased risk of thrombosis in heterozygous congenital dysplasminogenemia

To assess the risk of thrombosis in congenital dysplasminogenemia, we studied 10 unrelated families with this disorder. The probands were excluded from the analysis of data to prevent bias in the selection of subjects. Positive thrombotic histories were found in 1 of the 25 family members determined to have heterozygous congenital dysplasminogenemia and in 2 of their 41 biochemically unaffected relatives. The percentages of family members with no history of thrombosis up to a given age among subjects with and without congenital dysplasminogenemia were analyzed by the Kaplan-Meier method. No significant difference between the 2 groups was observed by generalized Wilcoxon test (P = .32) or Cox-Mantel test (P = .62). These findings suggest that heterozygous congenital dysplasminogenemia is not associated with an increased risk of thrombosis.

Intracellular degradation of histidine-rich glycoprotein mutants: tokushima-1 and 2 mutants are degraded by different proteolytic systems

We reported the first case of a congenital histidine-rich glycoprotein deficiency (HRG Tokushima) in which substitution of Gly85 with Glu (G85E) in the first cystatin domain resulted in intracellular degradation and a low plasma level of HRG [Shigekiyo, T. et al. (1998) Blood 91, 128-133]. Recently, we identified the gene mutation of a second case of HRG deficiency as a Cys223 to Arg (C223R) mutation in the second cystatin domain. To investigate the molecular and cellular bases of these deficiencies, we expressed these HRG mutants in baby hamster kidney (BHK) cells. Pulse-chase experiments in the absence and presence of various proteinase inhibitors revealed that, while wild-type HRG was completely secreted during 4-h chase periods, both the G85E and C223R mutants were only partially secreted and primarily degraded within the cells. The intracellular degradation of the C223R mutant was almost completely inhibited in the presence of a proteasome inhibitor, lactacystin, carbobenzoxy-leucyl-leucyl-leucinal or N-acetyl-leucyl-leucyl-norleucinal, resulting in increased secretion of the C223R mutant, and thus implicating the proteasome system in this degradation process. In contrast, the sum of the amounts of the G85E mutant inside and outside the cells decreased during the chase periods even in the presence of the proteasome inhibitor, carbobenzoxy-leucyl-leucyl-leucinal or N-acetyl-leucyl-leucyl-norleucinal, although proteasome-specific inhibitor lactacystin and one of the cysteine protease inhibitors, E-64-d, prevented the intracellular degradation. These results suggested that intracellular degradation of G85E HRG occurred to some extent through a hitherto unknown mechanism. Similar studies involving recombinant mutants in which Gly85 or Cys223 was replaced with several other amino acids revealed that proteins with mutations leading to the destruction of the predicted b-sheet structure of the cystatin domains were eliminated by the intracellular quality control system.

HRG Tokushima: molecular and cellular characterization of histidine-rich glycoprotein (HRG) deficiency

Previously, we found the first congenital deficiency of histidine-rich glycoprotein (HRG) in a Japanese woman with thrombosis. To elucidate the genetic basis of this deficiency, we first performed Southern blot analysis and found no gross deletion or insertion in the proband's HRG gene. We then examined the nucleotide sequences of all seven exons of the proband's HRG gene. A single nucleotide substitution, G to A at nucleotide position 429, which mutates Gly85 to Glu in the first cystatin-like domain, was found in exon 3 in 13 of 22 amplified clones. This mutation generates a unique Taq I site. Exon 3 was amplified from the proband, her family members, and 50 unrelated normal Japanese individuals, and Taq I fragmentation was examined. Fragmentation of exon 3 was observed in one allele of the genes from the proband and the family members who also have decreased plasma levels of HRG. Fifty unrelated normal Japanese individuals had a normal HRG gene, indicating that the G to A mutation is not a common polymorphism. To elucidate the identified mutation as a cause for the secretion defect of HRG in the proband's plasma, we constructed and transiently expressed the recombinant Tokushima-type HRG mutant (Gly85 to Glu) in baby hamster kidney (BHK) cells, and examined an intracellular event of the mutant protein. The results showed that only about 20% of the Tokushima-type HRG was secreted into the culture medium, and intracellular degradation of the mutant was observed. Thus, the present study strongly suggests that the HRG deficiency is caused by intracellular degradation of the Gly85 to Glu mutant of HRG in the proband.

Interferon alpha-2a therapy for disseminated intravascular coagulation in a patient with blue rubber bleb nevus syndrome. A case report

The authors present a sixteen-year-old girl with blue rubber bleb nevus syndrome (BRBNS) associated with disseminated hemangiomas involving the skin, oral cavity, skeletal muscle, and cerebrum. Although she denied neurologic symptoms, magnetic resonance imaging of the brain demonstrated dilatated cerebral veins and the Chiari I malformation. Examination of hemostasis revealed disseminated intravascular coagulation (DIC) manifesting as Kasabach-Merritt syndrome, with the potential for life-threatening bleeding or thrombosis in the central nervous system. Since successful management of life-threatening hemangiomas with interferon alpha-2a (IFN alpha-2a) has been reported, the authors administered IFN alpha-2a with an improvement in hemostasis. These findings suggest that IFN alpha-2a therapy is beneficial for relieving the life-threatening consumptive coagulopathy associated with BRBNS.

A novel missense mutation in the endoglin gene in hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by multisystem vascular dysplasia and recurrent hemorrhage. Recent investigation has mapped one of the responsible genes for HHT to chromosome 9q33-q34; subsequently, nine different mutations have been identified in the endoglin gene, which encodes a transforming growth factor beta (TGF-beta) binding protein, in nine unrelated families with HHT. We examined the endoglin gene in a Japanese patient with HHT and her family members. Using PCR-SSCP analysis followed by sequencing, we identified a C to A missense mutation in exon 4 which changed an Ala160 codon(GCT) to an Asp160 codon (GAT). Since this mutation destroys one of three Fnu4H 1 sites in exon 4, the Fnu4H I digestion patterns of the PCR-amplified exon 4 fragments from each family member were analyzed. In affected members, the restriction patterns were all consistent with a phenotype of HHT. PCR-amplified exon 4 fragments from 150 normal individuals were also analyzed by allele-specific oligonucleotide hybridization analysis. As a result, the mutation was not found in any of them. We conclude that the C to A mutation in exon 4 of the endoglin gene in this proband is responsible for the occurrence of HHT in this family.

Molecular pathogenesis of type I congenital plasminogen deficiency: expression of recombinant human mutant plasminogens in mammalian cells

We previously reported the genetic abnormality in a Japanese family with type I congenital plasminogen deficiency caused by a Ser572 to Pro572 mutation. To characterize the molecular pathogenesis of the disease in this family, we expressed recombinant human wild-type and mutant (rS572P) plasminogens in COS-1 cells. Activation-resistant wild-type and mutant plasminogen stable transfectants in CHO-K1 cells also were established. Transient transfection and metabolic labeling experiments followed by immunoprecipitation analysis showed that the mutant plasminogen was secreted from COS-1 cells in reduced amounts, compared with the wild type. Endo H digestion of the wild-type and mutant plasminogen showed no shift in their migrations on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, indicating that both contain complex type oligosaccharide structures and could therefore be secreted. Furthermore, the secretion of activation-resistant mutant plasminogen was significantly reduced. Pulse-chase experiments and Northern blot analysis showed that the impaired secretion of the mutant plasminogen was the consequence of the accumulation of the mutant protein inside the cells but not of reduced plasminogen mRNA. Immunocytochemical staining of stable transfectants also revealed that CHO-K1 cells expressing the activation-resistant mutant plasminogen stained mainly in the perinuclear area, suggesting delayed processing of the mutant protein in the intracellular transport pathway. We conclude that the impaired secretion of mutant plasminogen, due to intracellular accumulation, is the molecular pathogenesis of type I congenital plasminogen deficiency caused by a Ser572 to Pro572 mutation.

A case of dermatomyositis complicated by thrombotic thrombocytopenic purpura

A 60-year-old man with dermatomyositis was admitted to our hospital because of dyspnea and hypertension. He had high fever and convulsive seizures after admission. Laboratory examinations showed hemolytic anemia, thrombocytopenia, and renal failure. A clinical diagnosis of thrombotic thrombocytopenic purpura (TTP) was made. He failed to respond to plasma exchange therapy, pulse therapy with methylprednisolone, high-dose gamma-globulin therapy, and antiplatelet therapies with ticlopidine, dipyridamole and a prostacyclin analog of beraprost sodium. He died on his 17th day in hospital. Autopsy examination revealed widespread microthrombi in his kidneys, lungs, spleen, and intestine. Only seven cases of dermatomyositis or polymyositis complicated by TTP have been cited in the literature. TTP was fatal in 6 of these 7 cases. Early diagnosis and prompt treatment may improve the outcome of TTP patients with dermatomyositis. Dermatologists should keep in mind that TTP occasionally arises as a serious complication of dermatomyositis.

An in vitro system for identifying agents capable of changing serum lipoprotein(a) concentration by regulating the transcriptional activity of the apolipoprotein(a) gene promoter

A high serum concentration of lipoprotein(a) [Lp(a)] is a significant and independent risk factor for cardiovascular disease. We examined the effects of agents on the transcriptional activity of the apolipoprotein(a) [apo(a)] gene promoter and determined whether drugs identified by this assay would affect the serum concentration of Lp(a) in vivo. All-trans-retinoic acid (ATRA) and interleukin-6 increased the transcriptional activity of the apo(a) gene promoter 2.1- and 2.5-fold, respectively, whereas danazol reduced activity to 76% of the control value. Triiodothyronine had no effect on transcriptional activity. Treatment of two acute promyelocytic leukemia patients with ATRA induced maximal 2.7- and 3.2-fold increases in serum Lp(a) concentrations, respectively. Thus, the in vitro luciferase assay system is capable of identifying agents that affect the serum concentration of Lp(a) and thus may prove beneficial in the screening of new drugs for treatment of individuals with high serum Lp(a) concentrations.

Increase in plasma thrombomodulin level in patients with vibration syndrome

To determine whether endothelial cells are injured in vibration syndrome, we measured plasma levels of thrombomodulin (TM) in 100 patients with this syndrome using one-step sandwich enzyme immunoassay. Plasma level of TM in patients with vibration syndrome was significantly higher than that in normal control (p < 0.0001). There was no significant difference in the plasma TM level between patients with vibration syndrome and those with collagen disease. Plasma TM concentration in chain-saw operators was significantly higher than that in rock-drill operators (p < 0.05). Plasma TM value did not significantly differ between patients with vibration-induced white finger (VWF) and those without VWF. These results suggest that endothelial injury is present in patients with vibration syndrome, the degree of endothelial injury in patients with vibration syndrome equals that in patients with collagen disease, and the endothelial injury in chain-saw operators is greater than that in rock-drill operators. However, there was no difference in the degree of endothelial injury between patients with VWF and those without VWF.

Takayasu's arteritis associated with antiphospholipid antibodies. Report of two cases

The authors describe 2 patients with Takayasu's arteritis in whom lupus anticoagulant was positive and the titer of anticardiolipin antibody was elevated. One patient developed diffusely stenotic and occlusive changes in the multiple larger arteries. Histology of the small-sized arteries in another patient showed occlusive vasculitis without thrombosis, in addition to the findings in large-sized arteries compatible with Takayasu's disease. These findings are uncommon in Takayasu's arteritis. These findings suggest that antiphospholipid antibodies may have contributed to the pathogenesis of the extensive vasculopathy and may have triggered vasculitis in these patients.

A novel missense mutation in two families with congenital plasminogen deficiency: identification of an Ala675 to Thr675 substitution

We used a polymerase chain reaction (PCR) strategy and restriction fragment polymorphism analysis to evaluate all 19 exons of the plasminogen (PLG) gene in a Japanese patient with congenital PLG deficiency and her family members (family C). Sequence analysis following amplification of each exon and its flanking regions showed a single G to A transition in exon 17, resulting in the conversion of an Ala675 codon (GCT) to Thr675 codon (ACT). Since this mutation generates a new Mae III site, the Mae III digestion patterns of the PCR-amplified exon 17 fragments from each family member were analyzed. In all cases, the patterns correlated with the activities and antigen levels of plasma PLG in those members. The identical G to A transition in the same codon of exon 17 was detected by a Mae III digestion experiment in another proband and her family members with congenital PLG deficiency (family K). Furthermore, 20 normal individuals examined had no Mae III restriction site at this location. We conclude that a G to A transition in exon 17 is responsible for the congenital PLG deficiency inherited in these two Japanese families.

[Isolated iliac artery aneurysms associated with disseminated intravascular coagulation (DIC)]

An 84-year-old man was referred to our hospital on December 3, 1993, because of excessive bleeding after tooth extraction. Coagulation studies revealed thrombocytopenia (2.2 x 10(4)/microliter), increased serum levels of FDP-E (3172 ng/ml) and D dimer (42.6 micrograms/ml), and increased plasma levels of thrombin-atithrombin III complex (48.0 ng/ml) and plasmin-alpha 2-plasmin inhibitor complex (6.8 micrograms/ml). Computed tomography showed bilateral common iliac artery aneurysms. A diagnosis of DIC due to bilateral common iliac artery aneurysms was made. Heparin (10,000 U/day) administered to treat DIC resulted in good control, and operative repair of the aneurysms was successful. This is the second reported case of isolated iliac artery aneurysms associated with DIC.

Congenital deficiency of histidine-rich glycoprotein: failure to identify abnormalities in routine laboratory assays of hemostatic function, immunologic function, and trace elements

Histidine-rich glycoprotein (HRGP) has many biologic activities, but its physiologic function is still unclear. To show the physiologic function of HRGP, we studied five patients with congenital HRGP deficiency. Hemostatic screening tests, activities of natural anticoagulants and fibrinolytic proteins, markers of thrombin and plasmin generation, plasma levels of platelet-specific proteins, thrombin times with various concentrations of bovine thrombin, prolongation of thrombin time after addition of heparin or demartan sulfate, and contact activation of blood coagulation were normal or nearly normal in these patients. Serum concentrations of immunoglobulin, functional activity of the classical and the alternative pathway of complement, lymphocyte subsets, and serum concentrations of soluble interleukin-2 receptor were approximately normal in all patients, and serum concentrations of copper and zinc were completely normal. These results suggest that the physiologic functions of HRGP are limited when compared with its biologic activities. However, because the patients examined had plasma HRGP levels of 20% to 35% of normal, it is possible that 20% of normal HRGP level is sufficient for its physiologic functions.

High level of plasma thrombomodulin (TM) concentration and correlation with endothelin (ET)-1 in vibration-exposed patients

We measured plasma level of TM and ET-1 in vibration exposed patients. The results showed the plasma level of TM in vibration exposed patients was significantly higher than in normal controls. The present findings showed relatively wide damage of endothelial cells in the vascular bed of vibration-exposed patients. On the other hand, the mean level of ET-1 in these patients tended to be higher than in normal controls, though there was no difference. Further studies are necessary about the mechanism of endothelial damage in vibration syndrome patients and its contribution to peripheral circulatory disturbance of vibration syndrome including the role of ET-1.

Familial occurrence of two patients with malignant rheumatoid arthritis

In Japan, patients with rheumatoid arthritis associated with severe extra-articular manifestations due to vasculitis are diagnosed as having malignant rheumatoid arthritis. We report the occurrence of two cases of malignant rheumatoid arthritis in a Japanese family. Both patients, a father and son, expressed HLA-DR4 (Dw15), and were infected with Epstein-Barr virus. Moreover, the father developed malignant rheumatoid arthritis during reactivation of the Epstein-Barr virus. An unaffected male family member with the same HLA haplotypes was not infected by the virus. The possible role of the virus infection in the pathogenesis of malignant rheumatoid arthritis in a genetically susceptible family is discussed.

[An elderly patient with Takayasu's arteritis associated with antiphospholipid antibodies]

We report a patient with Takayasu's arteritis associated with antiphospholipid antibodies. An 84-year-old woman gradually developed gait and visual disturbances, dementia, myocardial infarction, and gangrene in all four limbs during a period of 8 years. Persistent inflammatory signs also continued for at least 8 years. Positive reaction for lupus anticoagulant by the diluted Russel viper venous time and positive reactions for cardiolipin antibodies were confirmed. However, she did not develop SLE. MR angiography revealed multiple and extensive occlusive changes in large vessels such as the aorta and its major branches. We believe antiphospholipid antibodies may have been related to severe occlusive vasculopathy in this patient.

Protein S Tokushima: abnormal molecule with a substitution of Glu for Lys-155 in the second epidermal growth factor-like domain of protein S

A 29-year-old female patient with heterozygous congenital protein S deficiency suffering from thrombotic disease had normal levels of both total and free protein S antigen (70% and 65%, respectively), but low cofactor activity (31%) for activated protein C, indicating that she had a variant of protein S, protein S Tokushima. Western blotting using the polyclonal anti-protein S antibody showed that approximately half of the patient's protein S appeared to be the variant with a higher molecular weight than normal protein S. The partially purified variant protein S bound neither to the monoclonal antibody recognizing calcium-dependent conformation of protein S nor to the antibody recognizing the thrombin-sensitive domain of protein S. Among the exons from II to XV of the patient's protein S gene encoding from the NH2-terminal end to the COOH-terminal end of protein S, only one missense mutation (A to G) was found in exon VI of the protein S alpha-gene, which results in amino acid substitution of Glu(GAG) for Lys-155(AAG) in the second epidermal growth factor-like domain of protein S. The recombinant protein S Tokushima expressed in BHK cells had a slightly higher molecular weight than the recombinant normal one, did not bind to the antibody specific for the thrombin-sensitive domain, and did not show the cofactor activity. These findings suggest that the protein S Tokushima molecule is structurally and functionally a variant of protein S, and that this variant protein S is the cause of severe thrombosis in this patient.

Congenital histidine-rich glycoprotein deficiency

The proband, a 43-year-old woman, suffered from right transverse sinus thrombosis during oral contraceptive treatment. A month after stopping the drug, her plasma activities of antithrombin III, protein C, protein S, heparin cofactor II, plasminogen and plasminogen activator inhibitor were normal, but her plasma histidine-rich glycoprotein (HRG) level was only 21% of the normal level of 109.5 +/- 51.5% (mean +/- 2 SD). The HRG concentrations in her plasma determined on four different occasions over 6 months were similar. She showed no clinical signs of liver insufficiency or sepsis. Low levels of plasma HRG (20% to 35% of normal) were also found in her aunt, uncle and two daughters. These results suggest that congenital HRG deficiency is inheritary in this family.

Protein S Tokushima: an abnormal protein S found in a Japanese family with thrombosis

An abnormal protein S (PS) was found in a Japanese family with a high incidence of thrombosis. The proband is a woman who was born in Tokushima Prefecture. She had superior sagittal sinus thrombosis, thrombophlebitis of the left leg, and thrombosis of the placenta. She had a normal plasma level of free PS antigen but decreased PS activity. Her mother and aunt also had thrombophlebitis of the leg, and together with four other family members also showed a normal level but decreased activity of PS. This suggests that hereditary dysfunction of PS is inherited in this family as an autosomal dominant trait. The proband's PS appears to have a slightly higher molecular weight than normal PS both in the intact and modified form, suggesting that it has a molecular defect on the carboxyl-terminal side of the thrombin-sensitive site. This abnormal PS with apparently unique characteristics was named PS Tokushima.

Congenital plasminogen deficiency caused by a Ser572 to Pro mutation

We used a polymerase chain reaction (PCR) strategy and restriction fragment polymorphism analysis to evaluate all 19 exons of the plasminogen (PLG) gene in a Japanese patient with congenital PLG deficiency and her family members. She presented with cerebral infarction. Sequence analysis following amplification of each exon and its flanking regions showed a single T to C transition in exon 14, which changed a Ser572 codon (TCC) to Pro572 codon (CCC). Since this mutation generates a new Fok I site, the Fok I digestion pattern of the PCR-amplified exon 14 fragments from each family member was analyzed. In all cases, the patterns were consistent with the activities and antigen levels of plasma PLG in those members. Furthermore, all PCR-amplified exon 14 fragments from 15 normal individuals were not restricted with Fok I endonuclease. We conclude that a T to C transition in exon 14 identified in the propositus is responsible for PLG deficiency inherited in this Japanese family with thrombotic episodes.

[Gammaglobulin infusion therapy in a patient with antiphospholipid syndrome]

A 47-year-old woman with antiphospholipid syndrome was referred to us for hemostatic control at the time of extraction of teeth. After administration of intravenous gammaglobulin of 0.4g/kg daily for 5 days, lupus anticoagulant activity disappeared and platelet count slightly increased. Furthermore, she had a transfusion of platelet-rich plasma before operation and no hemorrhagic or thrombotic complications occurred. These findings suggest that gammaglobulin infusion therapy is useful in preventing the complications at operation in patients with antiphospholipid syndrome.

[Activation of coagulation and fibrinolysis in patients with abdominal true aortic aneurysm associated with disseminated intravascular coagulation]

Two cases of abdominal true aortic aneurysm (AAA) associated with disseminated intravascular coagulation (DIC) were reported. Case 1 was an 81-year-old male who was admitted because of hematoma on the left leg and in whom was found by MRI an aortic aneurysm of 14 cm in diameter. Coagulation studies indicated DIC by revealing thrombocytopenia, hypofibrinogenemia and increased level of FDP. DIC was well controlled by surgical repair of the aneurysm after the administration of a small dose of heparin. Case 2 was a 60-year-old male who was admitted because of lumbago and hematoemesis and in whom was found by CT and echography an aortic aneurysm of 5.5 cm in diameter. Coagulation studies indicated DIC by revealing thrombocytopenia and an increased level of FDP. On the 2nd hospital day, he suddenly died due to the rupture of the aortic aneurysm. In most of 9 cases with AAA without DIC, plasma levels of thrombin-antithrombin III complex, plasmin-alpha 2 plasmin inhibitor complex and FDP-D dimer were also elevated. These findings indicate that the coagulation and fibrinolysis systems were generally activated in patients with AAA, and that DIC tends to occur in patients with a giant aortic aneurysm or an impending ruptured aneurysm.

Molecular and genetic analysis of a compound heterozygote for dysprothrombinemia of prothrombin Tokushima and hypoprothrombinemia

The molecular and genetic basis of a compound heterozygote for dys- and hypoprothrombinemia was analyzed. Abnormal nucleotide sequences of the human prothrombin gene were screened by PCR-single-strand conformation polymorphism (PCR-SSCP) with endonuclease digestion and mutated primer-mediated PCR-RFLP. A single nucleotide substitution responsible for dysprothrombinemia of prothrombin Tokushima was detected, as were three polymorphisms. The mutation for hypoprothrombinemia was detected by PCR-single-strand conformation polymorphism (PCR-SSCP) with endonuclease digestion in exon 6, near MboII-RFLP and NcoI-RFLP. Sequencing of PCR-amplified genomic DNA revealed a single base insertion of thymine (T) at position 4177. The resulting frameshift mutation caused both an altered amino acid sequence from codon 114 and a premature termination codon (i.e., TGA) at codon 174 in exon 7. Because exon 7 encodes the kringle 2 domain preceding the thrombin sequence, this frameshift leads to the null prothrombin phenotype. The inheritance of the hypoprothrombinemia gene from the father to the proband was proved by PCR-SSCP with endonuclease digestion and mutated primer-mediated PCR-RFLP.

Two new nonsense mutations in type Ia antithrombin III deficiency at Leu 140 and Arg 197

Using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing, the molecular basis of hereditary type Ia antithrombin III (AT III) deficiency was disclosed in two families. One mutation was a change from T to A in the codon of TTA for Leu 140 forming a stop codon of TAA, which was confirmed by mutated primer-mediated PCR-HindIII digestion. The application of this method demonstrated that all four affected members had the mutant allele in a heterozygous state and that none of unaffected subjects had this mutation. Another mutation in the second family was a change from C to T in the codon of CGA for Arg 197 also forming a stop codon of TGA, which was confirmed by PCR-HaeIII digestion. Based on these, it was concluded that the two new nonsense mutations in the AT III gene in a heterozygous state are the molecular basis of hereditary type Ia AT III deficiency.

Replacement therapy in a patient with congenital prekallikrein deficiency undergoing surgery

A patient with congenital prekallikrein (PK) deficiency underwent left endonasal radical ethmoidectomy and nasal polypectomy after receiving a transfusion of 6 ml/kg body weight of fresh frozen plasma (FFP). His plasma PK activity was under 1% before transfusion, and 46% after transfusion. The patient had no bleeding tendency during operation, but bled extensively from the wound 7 days after operation. At that time, his plasma PK activity was 3%. Since the bleeding could not be stopped simply by plugging his nasal cavities with tampons, he was given 3 ml/kg body weight of FFP. As a result, his nasal bleeding rapidly decreased. No clinical sign of thrombotic complication was observed throughout the clinical course.

Type I congenital plasminogen deficiency is not a risk factor for thrombosis

The risk of thrombosis in type I congenital plasminogen (PLG) deficiency has been suggested, but is still not confirmed. We studied 40 members of two unrelated families with this disease, and found that 21 were heterozygotes of type I congenital PLG deficiency. Three of them had thrombosis, but the other 18 had no thrombosis. The percentages of family members with no history of thrombosis up to a given age among subjects with type I congenital PLG deficiency and healthy controls were analyzed by the Kaplan-Meier method. No significant difference between the two groups was observed by the generalized Wilcoxon test (p = 0.23). These results suggest that there is no significant correlation between type I congenital PLG deficiency and thrombosis.

Detection of a single base substitution of the gene for prothrombin Tokushima. The application of PCR-SSCP for the genetic and molecular analysis of dysprothrombinemia

The genetic and molecular basis of a mutant prothrombin of 'prothrombin Tokushima' was studied by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and PCR-restriction fragment length polymorphism (PCR-RFLP) analyses. The abnormal gene was detected by altered migration by PCR-SSCP and by the loss of an MspI site by PCR-RFLP. The gene for prothrombin Tokushima was shown to be inherited from the mother of the proband. Sequencing analysis using PCR-amplified genomic DNA clarified a substitution of thymine (T) for cytosine (C) at position 9,490, changing arginine (Arg) to tryptophan (Trp) at position 418 of the polypeptide chain. This point mutation is assumed to be the molecular basis of prothrombin Tokushima, firstly, because of the absence of distinct changes in Southern blot analysis of the proband's DNA (using a full-length human prothrombin cDNA as a probe), secondly, because it has the same molecular weight as the abnormal gene product, and, thirdly, because of the absence of other amino acid abnormalities in the proteolytic peptide-fragments. It is concluded that PCR-SSCP and PCR-RFLP were useful for detecting the abnormal gene and for directly diagnosing the carrier status of dysprothrombinemia. This is the first report of gene analysis of dysprothrombinemia.

Acquired factor VIII inhibitor in a patient with adenocarcinoma of the lung

A 58-year-old man developed an acquired factor VIII inhibitor in association with adenocarcinoma of the lung. Laboratory examinations showed a marked prolonged activated partial thromboplastin time and a low level of factor VIII activity. Further study revealed his serum to have a factor VIII inhibitor which was characterized as an IgG. Treatment with prednisolone was successful in reducing the inhibitor so that the bleeding manifested by epistaxis and subcutaneous hemorrhages in the extremities ceased. Circulating inhibitors against factor VIII associated with malignancies appear to be very rare. Fourteen patients with factor VIII inhibitors associated with malignancies were reviewed.

[Congenital plasminogen deficiency in a Japanese family]

A Japanese family with congenital plasminogen deficiency was described. The propositus was a 43-year-old woman, who complained of the attack of tonic convulsion. Her maternal grandfather was died of myocardial infarction and grandmother died of cerebral infarction. Her mother had thrombosis of the left femoral artery at the age of 56 years. She was made a diagnosis of late onset epilepsy due to cerebral infarction or cerebral tumor by electroencephalography, brain CT, and brain MRI. Her plasma plasminogen activity determined using chromogenic substrate was 54%, and the plasma level of plasminogen antigen measured by single radial immunodiffusion was 4.8 mg/dl. Family studies revealed parallel decreases in plasminogen activity and antigen levels in her mother and second daughter. These data suggest that congenital plasminogen deficiency is inherited as an autosomal dominant defect in this family.

Mechanism of potentiation by manganese ion of aggregation of porcine pancreatic elastase-treated human platelets

The effect of manganese ion (Mn2+) on the aggregation of porcine pancreatic elastase-treated platelets (ETP) induced by fibrinogen (Fbg) was studied. Mn2+ enhanced the aggregation of ETP on addition of Fbg specifically and dose-dependently. This effect of Mn2+ was not associated with the formation of thromboxane A2, and was not affected by pretreatment of ETP with acetylsalicylic acid in the presence of Mn2+. Moreover, it was not dependent on extracellular adenosine diphosphate, as shown by removal of extracellular adenosine diphosphate by pretreatment of ETP with creatine phosphate/creatine phosphokinase. Studies on the binding of 125I-Fbg to ETP showed that Mn2+ increased the Kd value of binding but did not affect the number of Fbg binding sites. These results indicate that Mn2+ specifically and dose-dependently potentiated Fbg-induced aggregation of ETP and that this effect of Mn2+ may be due to an increase in the affinity of binding of Fbg to the glycoprotein IIb-IIIa complex on the membranes of ETP.

Successful delivery in a case of essential athrombia

A successful delivery in a 26-year-old Japanese woman with essential athrombia was reported. A diagnosis of essential athrombia was made by clinical and laboratory features including bleeding tendency, prolonged bleeding time, normal platelet count, normal clot retraction and impaired platelet aggregation induced by ADP. Since the presentation was a frank breech at the end of the 39th week of pregnancy, cesarean section delivery was performed under good hemostatic control with transfusion of 7.3 x 10(11) platelets. No hemorrhagic complication was observed during the puerperium.

Inhibition of fibrin monomer polymerization by Bence Jones protein in a patient with primary amyloidosis

The mechanism of inhibition of fibrin monomer polymerization was studied in a patient with primary amyloidosis. Thrombin and reptilase times of the patient's purified fibrinogen (Fbg) were remarkably prolonged, and polymerization of the patient's fibrin monomer was disturbed. Fbg-Bence Jones protein (BJP) complex was demonstrated by immunoelectrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis on the patient's purified Fbg. The patient's BJP not only prolonged the thrombin time of normal Fbg but also inhibited the polymerization of normal fibrin monomer. These results suggested that in this patient fibrin monomer polymerization was inhibited by binding of BJP to Fbg.

Prothrombin Tokushima: characterization of dysfunctional thrombin derived from a variant of human prothrombin

A mutant prothrombin, designated prothrombin Tokushima, was purified from plasma of a proband with 12% of normal plasma clotting activity and 42% of normal prothrombin antigen. The purified preparation gave a single band with the same mobility as that of "prothrombin" by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The factor Xa-catalyzed proteolysis of prothrombin Tokushima examined by SDS-PAGE was found to be identical to that of "prothrombin." Subsequently thrombin Tokushima was prepared by CM-Sepharose CL-6B column chromatography after prothrombin activation by factor Xa. The molecular weight of thrombin Tokushima estimated by SDS-PAGE was identical to that of "thrombin." Thrombin Tokushima exhibited less than 22% of normal clotting activity, and the value of kcat/Km (mumol/L-1 second-1) was less than one tenth of that of "thrombin" when Boc-Val-Pro-Arg-4-methylcoumaryl-7-amide was used as a substrate. However, active site titration using p-nitrophenyl-p'-guanidinobenzoate failed to detect any difference between the two. Thrombin Tokushima was 2.5% as effective as "thrombin" in inducing platelet aggregation. Interaction of thrombin Tokushima with antithrombin III was much slower than "thrombin" when followed by SDS-PAGE. Based on the residual thrombin activity, it was 33% as effective as "thrombin" in forming a complex with antithrombin III. These results indicate that the molecular defect resides in the thrombin portion of prothrombin Tokushima and that the binding sites for various substrates appear to be greatly impaired.