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)

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 is the most common hereditary condition associated with venous thrombosis. It is in a majority of cases due to a single point mutation in the factor V gene (FVR506Q). Currently used functional APC-resistance tests have 85-90% sensitivity and specificity for the FVR506Q mutation. A modified test which includes predilution of patient plasma in factor V depleted plasma has increased the sensitivity and specificity for the factor V mutation. However, neither the original nor the modified APC-resistance test have been evaluated in patients with acute thrombotic events. We have therefore used the original and the modified APC-resistance tests in 220 patients with clinically suspected acute deep venous thrombosis and in 278 healthy controls. The FVR506Q mutation was determined in all patients. The patients were classified as either DVT (deep venous thrombosis)-negative or DVT-positive depending on the outcome of contrast phlebography. In individuals with normal factor V genotype, the original APC-resistance test gave significantly lower APC-ratio values both in DVT-positive and DVT-negative patients than in healthy controls. The specificity of the original APC-resistance test for the FVR506Q mutation in controls and in DVT-negative and DVT-positive patients were 85%, 54% and 28%, respectively, when a cut off APC-ratio of 3.2 which insured 100% sensitivity was used. Using the modified APC-resistance test, essentially no difference in APC-ratios between patients with normal factor V genotype and healthy controls with normal factor V genotype was observed. The modified APC-resistance test had a specificity for the FVR506Q mutation of 98.8% at an APC-ratio cut off of 2.1 which ensured 100% sensitivity. The original APC-resistance test gave lower APC-ratios in women than in men and in patients with acute thrombosis as compared to controls. In conclusion, the modified APC-resistance test is highly sensitive and specific for the FVR506Q mutation. This test can be used in clinical practice as an easy to perform screening test for the FVR506Q allele. Moreover, the test performs equally well in patients with acute suspected venous thrombosis as in healthy controls.
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PMID:Evaluation of original and modified APC-resistance tests in unselected outpatients with clinically suspected thrombosis and in healthy controls. 915 92

The HELLP syndrome (HS) belongs to the list of obstetric complications believed to be associated with coagulation disorders. It was formerly thought that chronic intravascular clotting (DIC) in the placental vessels was the main cause. A hypercoagulable state has been reported in cases of severe HS associated with microvascular abnormalities that may involve cerebral, placental, hepatic and renal vessels. A case of acute pancreatitis and DVT of inferior cava in a pregnant woman, presenting with HS at 29 weeks, who was found to have a R506Q mutation, is reported. Preeclampsia-associated pancreatitis and DVT have rarely been reported. It is hypothesized that APC-R and Factor V Leiden mutation may prove to be new and more important markers capable of predicting a more significant maternal morbidity associated with HS. Thrombosis prophylaxis may be considered during pregnancy in order to reduce hazardous multiorgan failure (MOF) in women who are heterozygous for Factor V Leiden mutation.
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PMID:Acute pancreatitis and deep vein thrombosis associated with HELLP syndrome. 1023 Feb 42

The European Concerted Action on Thrombosis (ECAT) DVT Study was a collaborative study of preoperative haemostatic tests in prediction of DVT (diagnosed by routine bilateral venography) after elective hip replacement. 480 patients were recruited in 11 centres across Europe. Clinical risk factors were assessed, and stored citrated plasma aliquots were centrally assayed for 29 haemostatic factors according to the ECAT methodology. 120 (32%) of 375 evaluable patients had DVT, and 41 (11%) had proximal DVT. Among clinical variables, DVT was significantly associated with increased age, obesity, and possibly non-use of stockings. Of the 29 haemostatic factors, mean preoperative levels were significantly higher in patients with subsequent DVT (on univariate analyses) for factor VIII activity, prothrombin fragment F1+2, thrombin-antithrombin complexes, and fibrin D-dimer; and significantly lower for APTT and APC sensitivity ratio. Factor V Leiden was also associated with DVT. Most of these variables were also associated with age, while D-dimer was higher in patients with varicose veins. On multivariate analyses including clinical variables, only a shorter APTT (locally but not centrally performed) and APC resistance showed a statistically significant association with DVT. We conclude that (a) DVT is common after elective hip replacement despite prophylaxis; (b) the study provides some evidence that DVT is associated with a preoperative hypercoaguable state; and (c) preoperative haemostatic tests do not add significantly to prediction of DVT from clinical variables, with the possible exception of APC resistance.
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PMID:Prediction of deep vein thrombosis after elective hip replacement surgery by preoperative clinical and haemostatic variables: the ECAT DVT Study. European Concerted Action on Thrombosis. 1040 61