Laboratory tests for protein C deficiency

Khor, Bernard; Cott, Elizabeth M. Van

doi:10.1002/ajh.21679

Cited by 47 publications

(81 citation statements)

References 33 publications

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“…Clinical presentation of PC deficiency is variable (Aiach and Gandrille, 1996), associated with an increased risk of venous thromboembolic complications in young adulthood without apparent cause (Khor and Van Cott, 2010), such as deep vein thrombosis and pulmonary embolism. An estimated prevalence of the heritable PC deficiency is reported ranging from 0.2 to 0.5% (Esmon, 1987;Miletich et al, 1987).…”

Section: Introductionmentioning

confidence: 99%

Different impact of two mutations of a novel compound heterozygous protein C deficiency with late onset thrombosis

et al. 2014

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ABSTRACT. We investigated the alteration of coagulation state in a protein C (PC) deficiency pedigree and the impact of the PC gene mutations. The pedigree of a proband with cerebral hemorrhagic infarction had sixteen members with four generations. The plasma levels of PC activity (PC:A), protein S activity (PS:A), factor V:C and factor VIII:C, and routine coagulation tests were measured. Nine exons of the PC gene (PROC) were sequenced. Plasma PC:A and PC antigen (PC:Ag) of the proband were 26 and 18%, respectively, which was significantly lower than normal ranges. Two heterozygous missense mutations of PC in the proband were identified, T>G at site 6128 (exon 7) and G>C at site 8478 (exon 9) resulting in F139V and D255H, respectively. The family members with F139V (N = 4) or D255H (N = 4) had lower levels of PC:A and PC:Ag than members with wild-type 2970

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Section: Introductionmentioning

confidence: 99%

Different impact of two mutations of a novel compound heterozygous protein C deficiency with late onset thrombosis

et al. 2014

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“…This will identify the majority of patients with FVL, who may also be identified directly by using genetic testing by polymerase chain reaction, but not all mutations lead to lowering of the APC ratio. 8 Vascular graft thrombosis secondary to activated protein C resistance…”

Section: Discussionmentioning

confidence: 99%

Vascular graft thrombosis secondary to activated protein C resistance: a case report and literature review

Pejkić¹,

Savić²,

Paripović³

et al. 2013

Vascular

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Hypercoagulability is a well-documented and prominent risk factor for venous thromboembolism. The role of thrombophilia in arterial thrombotic events is less well defined. A 52-year-old male patient with multiple atherogenic risk factors was admitted for non-healing pedal ulcer and absent distal pulses. Based on the clinical presentation, Doppler ultrasound and angiography findings, the patient underwent elective in situ bypass arterial reconstruction. The saphenous vein graft was of satisfactory quality and the procedure went routinely. Acute graft thrombosis on postoperative day 0 was recognized immediately and prompted an emergent surgical revision. No technical errors or anatomical/mechanical causes for failed reconstruction were found and the graft was successfully thrombectomized using a Fogarty balloon-catheter. Graft rethrombosis, however, ensued after several hours. Considering the absence of threatening limb ischemia and the idiopathic recurrent thrombosis, raising suspicion of prothrombotic state, conservative treatment was pursued. Postoperative thrombophilia testing proved positive for activated protein C resistance, mandating introduction of chronic oral anticoagulation. Six months later, the operated extremity is viable. Inexplicable vascular graft thrombosis, particularly if early and recurrent, should raise suspicion of underlying thrombophilia. If confirmed by laboratory testing, long-term secondary antithrombotic prophylaxis may be required.

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“…If only a quantitative antigenic assay is used, type II deficiency cannot be detected [1, 2]. Clot-based functional protein C assays can detect both types I and II deficiencies but can give falsely increased results with anticoagulant therapy, LAs, and FVL mutation, and falsely decreased results with elevated factor VIII levels (particularly >250%) or low protein S. The chromogenic assay is less affected by interfering substances and is more reproducible; however, it only assesses alterations in the activation and active sites of the protein (type IIa defects) and cannot detect defects in other sites (protein S, surface, or substrate binding sites) and therefore can overlook the rarer type IIb deficiencies [4, 7, 18, 37]. Functional assays, either chromogenic or clot-based, are recommended as initial screens with antigenic assays performed if results are abnormally low.…”

Section: Specific Hypercoagulable Disorders and Laboratory Studiesmentioning

confidence: 99%

“…Recent studies have shown that protein S also exerts its own anticoagulant activity by direct binding of factors V, VIII, and X, and appears to act as a cofactor for the tissue factor pathway inhibitor, which results in inhibiting tissue factor-mediated factor X activation [39, 40]. Hereditary protein S deficiency is transmitted in an autosomal dominant fashion and occurs in 0.2-0.5% in the general population and in 1-3% of patients with first VT [7, 37, 41]. Functional protein S levels range 20-64% in heterozygous patients [42].…”

Section: Specific Hypercoagulable Disorders and Laboratory Studiesmentioning

confidence: 99%

Hypercoagulable states: an algorithmic approach to laboratory testing and update on monitoring of direct oral anticoagulants

Nakashima

Rogers

2014

Blood Res

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Hypercoagulability can result from a variety of inherited and, more commonly, acquired conditions. Testing for the underlying cause of thrombosis in a patient is complicated both by the number and variety of clinical conditions that can cause hypercoagulability as well as the many potential assay interferences. Using an algorithmic approach to hypercoagulability testing provides the ability to tailor assay selection to the clinical scenario. It also reduces the number of unnecessary tests performed, saving cost and time, and preventing potential false results. New oral anticoagulants are powerful tools for managing hypercoagulable patients; however, their use introduces new challenges in terms of test interpretation and therapeutic monitoring. The coagulation laboratory plays an essential role in testing for and treating hypercoagulable states. The input of laboratory professionals is necessary to guide appropriate testing and synthesize interpretation of results.

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Laboratory tests for protein C deficiency

Cited by 47 publications

References 33 publications

Different impact of two mutations of a novel compound heterozygous protein C deficiency with late onset thrombosis

Different impact of two mutations of a novel compound heterozygous protein C deficiency with late onset thrombosis

Vascular graft thrombosis secondary to activated protein C resistance: a case report and literature review

Hypercoagulable states: an algorithmic approach to laboratory testing and update on monitoring of direct oral anticoagulants

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