Kaolin clotting time
Kaolin clotting time (KCT) is a sensitive test to detect lupus anticoagulants.[1] There is evidence that suggests it is the most sensitive test for detecting lupus anticoagulants.[2] It can detect factor VIII inhibitors but is sensitive to unfractionated heparin.[3]
History
KCT was first described by Dr. Margolis in 1958.[4]
Principle
KCT is similar to the activated partial thromboplastin time test, except it does not use exogenous phospholipid.[1] Thus, a confirmatory test that uses excess phospholipid is needed to validate the presence of lupus anticoagulants.[1]
Kaolin is the surface activator, and the test also requires small amounts of cell fragments and plasma lipids to provide the phospholipid surface required for coagulation.[1][3] Therefore, the sample quality is important for the validity of the test.[1]
Method
The test combines a test plasma with kaolin, and the time the clot (in seconds) is measured.[4]
Interpretation
If the KCT is less than 60 seconds, this suggests that the normal control plasma is contaminated with platelet fragments; therefore, the test is not valid.[3]
The KCT test/control ratio of greater than or equal to 1.2 indicates an inhibitor is present.[3] If the test/control ratio is between 1.1 and 1.2, the test is equivocal.[3]
See also
- Dilute Russell's viper venom time
- Partial thromboplastin time
- Tissue thromboplastin inhibition test
References
- 1 2 3 4 5 Radhakrishnan, Kottayam (2013). "Kaolin Clotting Time". Methods in Molecular Biology: 335–339. doi:10.1007/978-1-62703-339-8_25.
- ↑ Exner, T; Triplett, D. A.; Taberner, D. A.; Howard, M. A.; Harris, E. N. (1990). "Comparison of test methods for the lupus anticoagulant: International survey on lupus anticoagulants-I (ISLA-1)". Thrombosis and haemostasis 64 (3): 478–84. PMID 2128977.
- 1 2 3 4 5 "Kaolin Clotting Time [KCT]". Retrieved 26 November 2014.
- 1 2 Margolis, J (1958). "The kaolin clotting time; a rapid one-stage method for diagnosis of coagulation defects". Journal of clinical pathology 11 (5): 406–9. PMC 479806. PMID 13575555.