Kaolin Clotting Time

2013 ◽  
pp. 335-339 ◽  
Author(s):  
Kottayam Radhakrishnan
Keyword(s):  
Clotting Time ◽  
Kaolin Clotting Time

Scientific and Standardization Committee Communications Comparison of Test Methods for the Lupus Anticoagulant: International Survey on Lupus Anticoagulants-I (ISLA-1)

1990 ◽  
Vol 64 (03) ◽  
pp. 478-484 ◽  
Author(s):  
Thomas Exner ◽  
Douglas A Triplett ◽  
David A Taberner ◽  
Margaret A Howard ◽  
E Nigel Harris
Keyword(s):  
Lupus Anticoagulant ◽  
Test Methods ◽  
Positive Sample ◽  
Direct Proportion ◽  
Clotting Time ◽  
Preliminary Screening ◽  
Activated Platelets ◽  
Tissue Thromboplastin ◽  
Kaolin Clotting Time ◽  
Induced Defects

SummarySix lyophilized plasma samples were sent to 20 “expert” laboratories for assessment of lupus anticoagulant (LA). Four samples contained pooled LA of graded potency mixed with aged normal plasma. One contained LA plus cephalin phospholipid and one contained a nonspecific venom anticoagulant. Sixteen methods were used overall with some participants using up to 8 methods. Results were scored in regard to the known potencies of LA in the samples and other known induced defects.Activated partial thromboplastin time (APTT) tests used by most participants for preliminary screening were relatively sensitive, but non-specific. Platelet or phospholipid neutralization procedures (PNP) appeared to be sensitive and specific but showed a non-linear response to increased LA content. Kaolin clotting time (KCT) tests showed the most sensitive response to increased LA content but the weaker LA were not scored as abnormal by most laboratories as the samples may have contained platelet fragments. Other commonly used tests such as the tissue thromboplastin inhibition (TTI) test and the dilute Russell’s viper venom test (DRVVT) were carried out somewhat inconsistently. The variability in performance of tests in different laboratories indicates that standardization of methodology is urgently required.Generally it seemed that most clotting tests were “bypassed” by the addition of phospholipid to a known LA-positive sample in apparently direct proportion to their sensitivity. Sample preparation, especially prevention of contamination with activated platelets is a vital preliminary part in the assay of LA.

Rapid Screening Methods for Bleeding Disorders. A Three Year Survey

1964 ◽  
Vol 11 (02) ◽  
pp. 506-512 ◽  
Author(s):  
V. A Lovric ◽  
J Margolis
Keyword(s):  
Laboratory Tests ◽  
Capillary Blood ◽  
Screening Tests ◽  
Rapid Screening ◽  
Screening Methods ◽  
Bleeding Disorders ◽  
Routine Laboratory ◽  
Clotting Time ◽  
Kaolin Clotting Time ◽  
In Infants And Children

SummaryAn adaptation of “kaolin clotting time” and prothrombin time for use on haemolysed capillary blood provided simple and sensitive screening tests suitable for use in infants and children. A survey of three year’s experience shows that these are reliable routine laboratory tests for detection of latent coagulation disorders.

dRVVT Is more Sensitive than KCT or TTI for Detecting Lupus Anticoagulant Activity of Anti-β2-glycoprotein I Autoantibodies

1999 ◽  
Vol 81 (02) ◽  
pp. 256-258 ◽  
Author(s):  
A. Biasiolo ◽  
P. Rampazzo ◽  
T. Brocco ◽  
V. Pengo
Keyword(s):  
Lupus Anticoagulant ◽  
Anticoagulant Activity ◽  
Test System ◽  
Clotting Time ◽  
Lupus Anticoagulants ◽  
Glycoprotein I ◽  
Tissue Thromboplastin ◽  
The Mean ◽  
Kaolin Clotting Time ◽  
Antibody Preparations

SummaryAnti-β2-glycoprotein I (β2-GPI) antibodies behave as classical Lupus Anticoagulants (LA), as they inhibit phospholipid-dependent coagulation reactions and their activity disappears in the presence of excess exogenous phospholipids (PLs). We have recently shown that a certain amount of PLs in the dilute Russell Viper Venom Time (dRVVT) test system is required to express LA activity of anti β2-GPI antibodies. We have now extended this observation to two other tests, i.e., Kaolin Clotting Time (KCT) in which PLs are not added, and Tissue Thromboplastin Inhibition test (TTI) in which PLs are extremely diluted. In fact, affinity-purified antibody preparations from 5 patients with antiphospholipid syndrome did not express or only weakly expressed anticoagulant activity in both tests; the mean ratios of coagulation times obtained with purified antibodies and that of control buffer were 1.11 and 1.0 for KCT and TTI, respectively. On the contrary, the mean ratios in dRVVT were 1.31 and 1.49 at a PLs dilution of 1:8 and 1:64, respectively. Therefore, the presence of LA activity due to autoantibodies to β2-GPI is characterized by a positive dRVVT and negative or only weakly positive KCT and TTI.

scholarly journals Studies on the Nature of the Circulating Anticoagulant Directed against Antihemophilic Factor: With Notes on an Assay for Antihemophilic Factor

Blood ◽  
1962 ◽  
Vol 20 (2) ◽  
pp. 137-149 ◽  
Author(s):  
ROBERT T. BRECKENRIDGE ◽  
OSCAR D. RATNOFF
Keyword(s):  
Substrate Concentration ◽  
Clotting Time ◽  
Heat Stable ◽  
Concentration Dependency ◽  
Proportional Relationship ◽  
Kaolin Clotting Time ◽  
Antigen Antibody ◽  
Kinetics Of ◽  
Temperature Time ◽  
Antihemophilic Factor

Abstract Modification of the kaolin clotting time has produced a reliable, simple assay system for antihemophilic factor. This system has been utilized for an investigation of the nature and mode of action of the circulating anticoagulant directed against antihemophilic factor. The anticoagulant has been shown to be present in equal amounts in plasma and serum, to be associated with fractions II and III of plasma prepared by the method of Cohn, to be relatively heat stable and to be stable for prolonged periods at -20 C. Investigation of the kinetics of the anticoagulant-antihemophilic reaction has demonstrated its temperature, time, pH, and substrate concentration dependency. The anticoagulant is not inactivated during the reaction with antihemophilic factor, and there is a proportional relationship between the anticoagulant and the antihemophilic factor during their interaction. No antigen-antibody manifestations could be detected during the anticoagulant-antihemophilic factor reaction. These characteristics support the hypothesis that the inactivation of antihemophilic factor by specific circulating anticoagulants is enzymatic.

COMPARISION OF THE DETECTION OF LUPUS ANTICOAGULANTS USING THREE DIFFERENT METHODS AND THE PRESENCE OF ANTI-CARDIOLIPIN ANTIBODIES

1987 ◽  
Author(s):  
A Criel ◽  
B Gilbert ◽  
A Van Hoof ◽  
M Hidajat ◽  
A Louwagie
Keyword(s):  
Elisa Test ◽  
Activated Partial Thromboplastin Time ◽  
Detection Methods ◽  
Recurrent Abortion ◽  
Clotting Time ◽  
Lupus Anticoagulants ◽  
Cardiolipin Antibodies ◽  
Tissue Thromboplastin ◽  
Kaolin Clotting Time

Lupus anticoagulant (LAC) is an antibody directed against phospholipids which prolongs in vitro clotting assays. Several detection methods have been described; however all give some different results. Recently ELISA and RIA assays have been developed which detect IgG and IgM anti-cardiolipin antibodies. The aim of our study was to compare three different LAC tests with an ELISA anti-cardiolipin test. The tests used were : kaolin clotting time (KCT or Exnertest), tissue thromboplastin inhibition test (TTI or Schleider test), activated partial thromboplastin time using a 50, 100, 200 fold dilution of the phospholipid preparation (APTT dilution test), and an IgG and IgM anti-cardiolipin ELISA test. 114 samples of patients suffering from diseases known to be accompanied with LAC antibodies (auto-immune diseases, recurrent abortion, thromboembolism, etc.) were studied. Positivity with one of the tests was found in 45 patients (39%). Patients with the diagnosis of SLE or otherimmune diseases showed the highest positivity (56%) whereas those with thromboembolism, recurrent abortion etc. were only positive in 27%.Among these 45 positive patients the TTI was positive in 41 cases (91 %);however in 10 cases (24 %) this was the only positivity found. The KCT test and the APTT dilution test were both positive in 18 cases (40 %). Anti-cardiolipin antibodies were found in 21 patients (47 %): IgG only in 12 (27 %), IgM only in 5 (11 %), both IgG and IgM in 2 (4 %); in 19 of these 21 patientsthe TTI was also positive.In our study the TTI test seems to be the most sensitive test but possibly also the test with the highest aspecific positivities. IgG and IgM anti-cardiolipin antibodies were less frequently found than expected.

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