Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Resistance to activated protein C (RAPC) has been described recently as a cause of trombophilia; this may justify up to 50% of thromboembolic disease without predisposing cause in patients under 45 years. A 29 years-old male with a previous deep venous thrombosis (DVT) in the lower left limb three years earlier, developed a DVT in the right lower limb after a trauma of the knee that required immobilization, was associated to pulmonary thromboembolism diagnosed by gammagraphic methods. The phlebographic study showed femoro-iliaco-caval venous thrombosis. The proband's father and a younger brother had a previous history of thrombotic episodes. The following tests, were performed in the proband and relatives: prothrombin time, aPTT, thrombin time, fibrinogen, (Von Clauss), antithrombin III (chromogenic), protein C and protein S (coagulometry and ELISA), plasminogen (chromogenic) and lupus anticoagulant (ITT, dRVVT, aCL). RAPC was evaluated in two different samples. The proband study was performed under oral anticoagulation treatment (OAT). Control groups were: 21 blood donors and 12 OAT patients. The results showed a decreased response to APC in the proband (ratio 1.5) and relatives: father (1.4), brothers (1.5 and 1.5), while the mother was within the normal range (> or = 2). In normal controls and OAT patients the ratio was over 2. No other abnormalities were detected in the assays performed. It is concluded that RAPC is the cause of this familial trombophilia. RAPC should be included in the evaluation study of trombophilia.
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PMID:[Familial thrombophilia due to resistance to activated protein C]. 798 58

Several parameters of fibrinolytic and protein C pathways were evaluated in three groups of patients with high (HR), moderate (MR) and low (LR) postoperative thrombotic risk undergoing major gynaecological surgery. The HR and MR groups were subjected to low molecular weight heparin (LMW) prophylaxis. A significant increase in plasminogen activator inhibitor type 1 (PAI-1) antigen and activity levels was observed in the HR patient group in comparison with the MR and LR groups in the preoperative and early postoperative period. In all the groups studied, the maximum increase in the levels of PAI-1 was seen on day 1 after surgery. However, the D-dimeric levels reached the highest level on day 7. A significant increase in activated protein C:alpha 1 antitrypsin (APC:alpha 1AT) complex levels was observed in the HR group in comparison with the LR group, and a strong decrease in protein C inhibitor in the early postoperative period was detected in all the groups. In spite of heparin prophylaxis, 2 HR patients were diagnosed as deep vein thrombosis (DVT) during the postoperative period. Both patients showed pre-operative levels of PAI-1 antigen or activity and APC:alpha 1AT complexes above the mean + 1 SD of the pre-operative levels in the HR group. In conclusion, in HR patients a hypofibrinolytic and hypercoagulable state was detected in the pre-operative and early postoperative periods. The prophylactic LMW heparin dose used in the present report (20 mg/day x 7) was insufficient to prevent DVT in the HR group. At present our HR patients are given higher doses of LMW heparin (40 mg/day x 7).
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PMID:Alterations in fibrinolytic and protein C pathways in gynaecological surgery: low molecular weight heparin prophylaxis. 798 53

Although patients with thromboembolic disease frequently have family histories of thrombosis, well-defined defects such as inherited deficiencies of anticoagulant proteins are found only in minority of cases. Herein, we present a family study of 42 years old woman with recurrent deep vein thrombosis which occurred first time four years ago during pregnancy, in subclavian vein, in relation to cardiac stimulator implantation because of atrio-ventricular III(0) block. Her laboratory investigation demonstrated normal APTT time, prothrombin time, platelet number, antithrombin III and protein C activity. Plasma antiphospholipid antibodies contents was within the normal range. The result of activated protein C(APC) resistance test was abnormal (R=1.64). Family study revealed similar degree of APC-resistance defect in her DVT symptomatic mother and two healthy young daughters (R=1.73 and 1.54 respectively). Additionally, a slightly reduced total protein S plasma concentration was found in the patient and her two children. The influence of a slightly reduced protein S level on the results of APC-resistance was excluded by evaluation of normalized activated protein C sensitivity ratio (nAPC-SR) as described de Ronde and Bertina.
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PMID:[Thrombophilia in a family with resistance to activated protein C and protein S deficiency]. 861 15

APC resistance, due to a point mutation in factor V at amino acid position Arg506, has been identified as a major cause of inherited thrombophilia. Here we report the presence of the factor V Arg506-->Gln mutation in 2 Italian families. In 1 family 3 subjects heterozygous and 2 subjects homozygous for the factor V Arg506-->Gln mutation were identified. The only subject who developed a thrombotic event was a 20-yr-old girl who was found to be homozygous for the factor V Arg506-->Gln mutation. In the second family 10 subjects were identified to be heterozygous for the factor V Arg506-->Gln mutation; among them 2 developed a thrombotic event. In the same family 2 individuals were found to be homozygous for the mutation: the first had a myocardial infarction at age 25 yr and the second suffered from multiple episodes of deep venous thrombosis and had a stroke at age 24 yr. These data show that the risk of developing deep venous thrombosis for the carriers of the factor V Arg506-->Gln mutation is high in the families investigated. Furthermore our data imply that the factor V Arg506-->Gln mutation in its homozygous form may relate to myocardial infarction and stroke.
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PMID:Arterial and venous thrombosis in two Italian families with the factor V Arg506-->Gln mutation. 869 38

Patients with leg ulcers caused by venous insufficiency often show evidence of previous deep venous thrombosis. Resistance to activated protein C (APC resistance) is a newly identified, autosomal dominant inherited defect in the anticoagulant system which significantly predisposes affected individuals to develop venous thrombosis. To elucidate the significance of APC resistance in venous leg ulcer patients, APC resistance was determined in plasma samples obtained from 46 unselected, consecutive patients with venous leg ulcers, admitted to hospital during a 6-month period. Twelve of the 46 patients (26%: 95% confidence limits, 14-41%) had APC resistance. APC resistance is thus a common anticoagulant deficiency among patients with venous leg ulceration and should be considered a risk factor for the development of venous leg ulcer disease.
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PMID:Resistance to activated protein C: a common anticoagulant deficiency in patients with venous leg ulceration. 929 2

The presence of point mutation G-->A of nucleotide 1691 of Factor V gene (Leiden mutation) is responsible for the resistance of factor Va to activated protein C (APC-resistance) and is associated with an increased risk for thrombosis. Herein, we reported on a case of 20 year male with a two years history of recurrent, extensive deep vein thrombosis. His family history showed grand-mother from mother side, who died from thromboembolic disease many years ago. His laboratory investigation reveals abnormal results of APC-resistance test (R = 1.80) and normalized APC-resistance test sensitivity ratio (0.57). Moreover, on the basis of a sequence specific primer polymerase chain reaction (SSP-PCR) a heterozygous from (G/A at 1691 position) of Leiden mutation was found. Family study showed two between 8 others asymptomatic persons with abnormal results of APC-resistance test and heterozygous genotype.
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PMID:[Point mutation G-->A nucleotide 1691 factor V gene as a cause of developing thrombotic complications in a family with plasma resistance to activated protein C]. 884 15

The effect of oral contraceptive therapy was studied in five patients with homozygous activated protein C resistance. Patients with this congenital abnormality, in contrast to those with antithrombin, protein C or protein S deficiencies, showed only a mild thrombotic tendency. In fact, only two of six observations (one patient took the pill on two separate occasions many years apart) showed deep vein thrombosis. No patient had pulmonary embolism. Two additional patients had a superficial vein thrombosis of the legs. In two instances, a superficial vein thrombosis and a deep vein thrombosis, concomitant risk factors were present (immobilization and surgery for an ovarian cyst, respectively). However, compared with heterozygous for the same abnormality, the symptomatic homozygous patients with APC resistance appeared to develop thrombosis after a shorter period of oral contraception.
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PMID:Homozygous patients with APC resistance may remain paucisymptomatic or asymptomatic during oral contraception. 889 47

Resistance to activated protein C (APC-R) is at present considered the most frequent laboratory abnormality in patients with deep vein thrombosis. An increased risk for venous thrombosis is associated with the use of oral contraceptives (OCs). We recently described a statistically significant association between APC-R status and oral contraceptives use in a healthy group of women. We re-evaluated 50 healthy women taking low-dose combination OCs in order to consider a possible correlation between the APC sensitivity ratio (APC-SR) and different oral contraceptive formulations. Seven women showed an APC ratio < or = 2 (APC-resistant). Only one of the seven women was found to be heterozygous for Leiden factor V mutation. We observed no significant differences between normally sensitive and APC-resistant women in terms of duration of OC use, amount of estrogenic or progestogenic dose, or type of formulation. We conclude that APC-resistance associated with oral contraceptives use seems to occur only in predisposed subjects (in our results, about 12% of the healthy population).
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PMID:Resistance to activated protein C, associated with oral contraceptives use; effect of formulations, duration of assumption, and doses of oestro-progestins. 889 55

Resistance to activated protein C (APC resistance) was measured in 284 individuals (169 females, 115 males) with a history of objectively confirmed venous thrombosis and/or pulmonary embolism. A decreased APC resistance ratio was found in 75 patients (26%), 47 were females, 28 males. Factor V Leiden was investigated in 60 of 75 patients with APC resistance, of whom 46 were heterozygous, 4 homozygous. In 10 APC resistant patients the Arg 506 Glu mutation was not identified. The median age of the first thromboembolic event in patients with APC resistance was 42 years (range 15-82 years). Most patients had a history of deep vein thrombosis (83%), 28% had experienced pulmonary embolism. More unusual sites of thrombosis were the deep arm veins (7%) and mesenteric veins (one patient, 1.3%). 53% of patients developed the first thromboembolic event spontaneously. Precipitating conditions for thromboembolism were surgery in 9.3% and trauma in 8%. In one third of female patients the first thromboembolic event occurred in conjunction with pregnancy and delivery (14.8%) or oral contraceptives (19%). At the time of investigation 40% of patients with APC resistance had experienced recurrent thromboembolic events. The family history was positive in 60% of patients. We conclude that the clinical feature of APC resistance is similar to the feature of a deficiency of antithrombin, protein C and protein S. Pregnancy, delivery and oral contraceptives seem to be a relevant additional risk factors for thrombosis in females with APC resistance.
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PMID:Thrombotic tendency in 75 symptomatic, unrelated patients with APC resistance. 892 76

The diagnostic strategies and clinical characteristics of thrombophilia associated with heterozygous or homozygous factor V Leiden mutation have been determined according to the literature and to a personal study in 51 families. Factor V mutation was present in the 51 propositi and in 84 out of 125 family members (81 heterozygous, 3 homozygous). Venous thrombosis was observed in all the propositi, in 17 of the 84 family members with the mutation and in 6 of the 41 with a normal APC resistance test and no mutation. An associated protein C or protein S deficiency was present in 5 families (10%). The most frequent clinical manifestations were superficial or deep vein thrombosis and/or pulmonary embolism, but also thrombosis at an unusual site (cerebral, mesenteric or central retinal vein). A causal relationship is frequently difficult to demonstrate. A precipitating factor was observed in 84% of cases and a recurrent thrombotic episode occurred in 50% of propositi. The risk of thrombosis associated with pregnancy was high in the post-partum period, especially in homozygous women. In the 28 homozygous subjects, markers of coagulation activation were frequently elevated in untreated patients. Finally, the efficacy of anticoagulant treatment is suggested but the long period often observed between treatment interruption and a recurrence does not militate in favour of long term treatment.
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PMID:Diagnosis and clinical characteristics of inherited activated protein C resistance. 897 37


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