kaolinite and Lupus-Erythematosus--Systemic

Topics: Adrenal Cortex Hormones; Autoantibodies; Azathioprine; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Coagulation Tests; DNA; Factor VIII; Female; Fetal Death; Humans; Immunoglobulin G; Immunoglobulin M; Kaolin; Lupus Coagulation Inhibitor; Lupus Erythematosus, Systemic; Partial Thromboplastin Time; Phospholipids; Pregnancy; Pregnancy Complications, Hematologic; Prothrombin Time; Thrombosis; von Willebrand Factor

Spontaneous abortion (SA) is a common complication of pregnancy. Presence of lupus anticoagulant (LA), one of the antiphospholipid antibodies, has been associated with SA in many studies, especially in Caucasians. This study was carried out to determine the prevalence of LA in women with SA in ABUTH, Zaria.. A cohort of 100 consecutive women presenting with SA with no history of thrombotic episodes were enrolled into the study. Prothrombin time (PT), kaolin clotting time (KCT), and activated partial thromboplastin time (APTT) were conducted on samples of all the participants. Eight patients had prolonged APTT, and after a 50:50 mixture of their plasma with pooled control plasma, four (50%) had uncorrected APTT. Staclot® (a hexagonal-phase phospholipid) test and calculated Rosner index for prolonged KCT were used for the confirmation of LA in samples with uncorrected APTT after mixing studies.. We analyzed 100 women with one or more SA with a mean age of 31.0 ± 3.8 years. Nearly 4% and 3% of the participants were LA positive with Staclot® and KCT tests, respectively. Patients with LA were more likely to have had a past history of preeclampsia/eclampsia, small for gestational age deliveries, and previous SA (prevalence odds ratio [95% confidence interval]) of 1.9 (0.2, 20.1), 3.2 (0.3, 34.3), and 1.4 (0.1-13.6), respectively. The PT, APTT, and KCT were significantly prolonged in patients with LA (P ≤ 0.001 for each, respectively).. LA may be one of the causes of SA and other adverse pregnancy outcomes such as preeclampsia/eclampsia and small for date deliveries. It is recommended that patients with prolonged APTT, uncorrected with 50:50 mixing study with pooled control plasma, should be evaluated further for LA.

Topics: Abortion, Spontaneous; Adult; Female; Humans; Kaolin; Lupus Coagulation Inhibitor; Lupus Erythematosus, Systemic; Nigeria; Partial Thromboplastin Time; Pregnancy; Prevalence; Prothrombin Time; Thrombosis

The dilute Russell viper venom time and kaolin clotting time (KCT) are very sensitive screening tests for lupus anticoagulant activity. However, due to the high turbidity of the kaolin reagent it is difficult to accommodate the KCT on the optical end point automation of today. We evaluated five recently reported screening tests (the silica clotting time, the Textarin/Ecarin ratio, the Taipan venom time, the factor V ratio, and a kaolin clotting time using low-turbidity kaolin) as potential alternatives to the KCT. The sensitivity and specificity of the silica clotting time compared well to KCT, detecting 10/12 KCT positive samples and showing equal sensitivity to dilution of lupus positive plasma. In addition, the silica clotting time allows for a confirmatory phospholipid correction procedure. False-positive results were seen in 2 of 15 warfarinised samples. A second assay utilising the ratio of extrinsic/intrinsic factor V assays was not affected by either warfarin or heparin. This assay also gave positive results with 3 of 23 samples previously screened as lupus negative but exhibiting anticardiolipin positivity. It was therefore concluded that a combination of the silica clotting time and dilute Russell viper venom time met the requirements of lupus sensitivity with demonstration of phospholipid dependence and optical end point compatibility. The factor V ratio is a useful second-line screen for both anticoagulated patients and anticardiolipin antibody-positive samples.

Topics: Anticoagulants; Antiphospholipid Syndrome; Autoimmune Diseases; Automation; Blood Coagulation Tests; Elapid Venoms; Endopeptidases; Evaluation Studies as Topic; Factor V; False Positive Reactions; Heparin; Humans; Kaolin; Liver Diseases; Lupus Coagulation Inhibitor; Lupus Erythematosus, Systemic; Nephelometry and Turbidimetry; Partial Thromboplastin Time; Peptide Hydrolases; Postoperative Period; Prothrombin; Prothrombin Time; Silicon Dioxide; Warfarin

The presence of the lupus anticoagulant was diagnosed in six pregnant women because they had prolonged activated partial thromboplastin and kaolin clotting times which could not be corrected by dilution of test samples with normal plasma. All previous pregnancies (14) had ended in intrauterine death in the five multigravidas. Three women had had thrombotic episodes during pregnancy. The diagnosis of SLE was established in four. Antinuclear antibody was identifiable in all 6. All were treated with prednisone 40-60 mg/day and aspirin 75 mg/day. Suppression of the lupus anticoagulant activity was achieved in five patients, all of whom gave birth to live infants. In the sixth patient suppression of the anticoagulant activity was demonstrated between pregnancies; a further pregnancy in this patient was lost before she had received sufficient prednisone to suppress the anticoagulant. Since treatment with prednisone and aspirin can lead to successful pregnancies, it is important to screen all women with SLE, thrombotic episodes, recurrent intrauterine deaths, or a biologically false-positive VDRL for the presence of the lupus anticoagulant.

Topics: Adult; Antibodies, Antinuclear; Aspirin; Blood Coagulation Disorders; Blood Coagulation Factors; Female; Fetal Death; Humans; Immunoglobulins; Kaolin; Lupus Coagulation Inhibitor; Lupus Erythematosus, Systemic; Partial Thromboplastin Time; Platelet Count; Prednisone; Pregnancy; Pregnancy Complications, Hematologic; Pregnancy, Multiple; Thrombophlebitis

The lupus anticoagulant was identified in three patients. Laboratory studies gave evidence of inhibitory activity directed against phospholipid and prekallikrein. Inhibition of prekallikrein has not been reported previously. When exposed to kaolin, all three patients' plasmas failed to develop the level of fibrinolytic activity achieved by similarly treated normal plasma. The data suggest that compromised fibrinolytic capacity may be a contributing factor in the development of thrombosis in patients with the lupus anticoagulant.

Topics: Adolescent; Adult; Autoimmune Diseases; Blood Coagulation Factors; Female; Femoral Vein; Fibrinolysis; Humans; Kallikreins; Kaolin; Lupus Coagulation Inhibitor; Lupus Erythematosus, Systemic; Phospholipids; Prekallikrein; Procainamide; Thrombophlebitis

The kaolin clotting time of platelet poor plasma was used as a sensitive test for detecting the lupus anticoagulant in mixtures of normal and patients' plasmas. Platelets were found to decrease the anticoagulant effect of a typical lupus inhibitor. Thus, high sensitivity in this test system was achieved by ensuring low platelet concentrations and omitting platelet lipid substitute. In 17 patients with disseminated lupus erythematosus (DLE), 12 had detectable inhibitor by this method, more than would be detected with routine coagulation tests. Mixing patterns were of four distinct types, representing three different modes of anticoagulant behaviour. The pattern (type 3) of plasma mixtures giving longer kaolin clotting times than the individual components could be reproduced in vitro by adding trace amounts of crude thrombin or platelet fragments to a more typical lupus anticoagulant-containing plasma; formation of such a mixing pattern by the plasma of a patient with DLE may therefore indicate activation of the coagulation pathway. Six patients with idopathic thrombocytopenic purpura (ITP) had no detectable inhibitor indicating that anti-platelet antibodies behave differently from the lupus anticoagulant.

Topics: Blood Cell Count; Blood Coagulation; Blood Coagulation Tests; Blood Platelets; Female; Humans; Kaolin; Lupus Erythematosus, Systemic; Male; Purpura, Thrombocytopenic; Thrombin

A circulating anticoagulant in a suspected case of lupus erythematosus has been highly purified by a combination of Sephadex gel filtration and DEAE cellulose chromatography. The inhibitor is a gamma globulin with a sedimentation coefficient of 6.6 Svedberg units. For its anticoagulant action, the lupus inhibitor requires a co-factor which is present both in the lupus and normal blood. The cofactor is located in the gamma globulins fraction which is relatively heat stable, but less than the inhibitor, at 56 degrees C. The active lupus inhibitor (inhibitor + cofactor) is not species specific against human prothrombin. Working with highly purified systems, the active inhibitor is found to inhibit prothrombin conversion by formed prothrombin activator. It does not appear to inhibit the formation of prothrombin activator nor does it affect purified prothrombin.

Topics: Adult; Anticoagulants; Blood Coagulation Factors; Female; Humans; Kaolin; Kinetics; Lupus Erythematosus, Systemic; Platelet Count; Prothrombin Time