Reptilase Time

Coagulation

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Description

The Reptilase time is used for detecting deficiencies or abnormalities of fibrinogen.

Reptilase is an enzyme from the venom of the Bothrops jararaca (atrox) snake. It has similar activity to that of thrombin. However, unlike thrombin, reptilase is resistant to inhibition by antithrombin III. As a consequence, the reptilase time is not prolonged by heparin, hirudin, or direct thrombin inhibitors, unlike the thrombin time.

Reptilase also differs from thrombin by releasing fibrinopeptide A, but not fibrinopeptide B, in its cleavage of fibrinogen.

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Indications

The diagnostic significance of the Reptilase time is to be seen in connection with the determination of the thrombin time. A normal reptilase time in conjunction with a prolonged thrombin time suggests the presence of heparin in the sample. If both the reptilase and thrombin time are prolonged, this may be due to the presence of fibrinogen degradation products or a quantitative or qualitative fibrinogen disorder.

It is therefore suitable for:

·         monitoring fibrinolytic therapy by determination of fibrinogen/fibrin degradation products

·         diagnosis of afibrinogenaemia and dysfibrinogenaemia

·         elucidation of prolonged thrombin times in cases of suspected presence of heparin.

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Sample Type

Plasma (Citrate 2.7ml Blue) x 1 or frozen (-80°C) citrated (0.109M) single spun platelet poor plasma, frozen in less than 6 hours from venepuncture.

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Reference Range

Current adult reference range indicated on the report.

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Turnaround Time

Within 5 weeks

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Testing Frequency

As required (usually batched), please contact the laboratory for urgent requests.

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External Notes

The accuracy of all coagulation tests is greatly influenced by pre analytical variables. It is essential that sample quality is given the highest of priorities. Samples which fail to meet quality criteria including age of sample, specimen fill (>90%), haemolysed, clotted or activated samples will be rejected and a repeat sample requested.

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Patient Preparation

No special requirements.

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References

Mackie IJ, Kitchen S, Machin SJ, Lowe GD; Haemostasis and Thrombosis Task Force of the British Committee for Standards in Haematology. Guidelines on fibrinogen assays. Br J Haematol 2003; 121: 396-404.
Jennings I, Kitchen S, Menegatti M, Palla R, Walker I, Peyvandi F, Makris M. Potential misdiagnosis of dysfibrinogenaemia: data from multicentre studies amongst UK NEQAS and PRO-RBDD project laboratories. Int J Lab Hematol 2017; 39: 653-62.

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See Also

Clauss Fibrinogen
Thrombin Time
Fibrinogen Antigen

Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.