The association of vitamin-D level with catheter-related-thrombosis in hemodialysis patients: A data mining model

Purpose: This study aims to investigate the association of different risk factors including vitamin-D level with catheter-related-thrombosis in hemodialysis patients by applying data mining techniques. Methods: This study used the retrospectively approach and was done based on the CRISP-DM framework. The data of 1048 hemodialysis patients of Hasheminejad Kidney Center whose first catheterization was between 2014 and 2019 was used for analysis. In this study, patients with a previous history of deep venous thrombosis, thrombophilic condition, and undergone anticoagulant therapy were excluded. The decision tree J48 in WEKA software was used for modeling. The K-fold cross-validation method was also used to evaluate the classification performance. Finally, the model was evaluated by using Confusion Matrix and F-Measure. Results: The approved model was accurate in 70.3% of the predictions, and it demonstrated an association between patients’ vitamin-D range and catheter-related-thrombosis. Conclusion: The results indicated that in hemodialysis patients without the history of cancer or high blood pressure, vitamin-D had a significant impact on catheter related thrombosis.

Guidelines for lupus anticoagulant testing in South Africa

The antiphospholipid syndrome (APS) is a thrombophilic condition characterised by thromboses and/or adverse pregnancy outcomes. International criteria for the diagnosis of APS require that certain laboratory and clinical criteria are met. Lupus anticoagulant (LA) testing using coagulation tests is an essential component. This review aims to provide a national guideline for LA testing in the South African context and intends to standardise testing, interpretation and reporting of results. Key aspects of the pre-analytical, analytical and post-analytical phases of testing are considered and highlighted.

Primary Thrombophilia in Mexico XIII: Localization of the Thrombotic Events in Mexican Mestizos With the Sticky Platelet Syndrome

The sticky platelet syndrome (SPS) is a common cause of both arterial and venous thrombosis, being a dominant autosomal disease with qualitative platelet alterations and familial occurrence. It is characterized by platelet hyperreactivity with increased platelet aggregability in response to low concentrations of platelet agonists: epinephrine, adenosine diphosphate, or both. The clinical manifestations involve venous or arterial thrombosis, recurrent pregnancy loss, and fetal growth retardation. To analyze the localization of the thrombotic episodes in a cohort of Mexican mestizo patients with SPS. Between 1992 and 2016, 86 Mexican mestizo patients with SPS as the single thrombophilic condition were prospectively identified; all of them had a history of thrombosis. There were 15 males and 71 females. The thrombotic episodes were arterial in 26 cases and venous in 60 (70%). Arterial thrombosis was mainly pulmonary thromboembolism, whereas venous thromboses were identified most frequently in the lower limbs. Mexican mestizo population with SPS is mainly female; the type I of the condition is the most frequent; both arterial and venous thrombosis can occur, and they are mainly pulmonary embolism and lower limbs venous thrombosis, respectively.

The Wolf Hidden behind the Clots: Catastrophic Antiphospholipid Antibody Syndrome

Catastrophic antiphospholipid syndrome (CAPS) is a rare but highly fatal clinical syndrome that occurs in up to 1% of patients with antiphospholipid syndrome (APS). The diagnosis of CAPS is often delayed because its presentation with multiple organ thromboses can be confused with other thrombotic microangiopathies and severe sepsis. We report a case of CAPS in a patient with APS and systemic lupus erythematosus (SLE) presenting with thrombotic storm precipitated by trauma, cytomegalovirus (CMV) infection, and noncompliance with anticoagulation therapy. Our case reflects the “two-hit hypothesis” of APS in which the presence of antiphospholipid antibodies (first hit) increases the thrombophilic risk, and thromboses take place in the presence of another thrombophilic condition such as CMV infection in our case. In this case review, we discuss the diagnostic challenges and management of CAPS. In clinical practice, we aim to stress the importance of thorough evaluation and management of precipitating events such as infections in addition to timely diagnosis and treatment of this catastrophic clinical entity.

ABO blood group and thrombotic vascular disease

SummaryABO blood group antigens are complex carbohydrate molecules expressed on red blood cells and a variety of tissues. The ABO blood type is implicated in the development of a number of human diseases and there is increasing evidence regarding its involvement in the pathogenesis of cardiovascular disorders, mainly through its effect on von Willebrand factor levels. In this review, after a brief analysis of the potential molecular mechanisms by which the blood group influences haemostasis, we focus on the clinical implications of such interaction. Overall, the literature data document the close relationship between venous thromboembolism (VTE) and non-O blood type, which is associated with an approximately two-fold increased risk of venous thrombosis. A supra-additive effect on VTE risk is observed when an inherited thrombophilic condition is associated with non-O blood group. A weaker association exists between non-O blood type and arterial thrombosis, which needs to be further investigated.

The Antiphospholipid Syndrome

The antiphospholipid syndrome (APS) is an autoimmune thrombophilic condition that is marked by the presence of antibodies that recognize phospholipid-binding proteins. The clinical manifestations of APS include vascular thrombosis and pregnancy complications, especially recurrent spontaneous miscarriages. This article provides an update on diagnostic and therapeutic approaches to this disorder.

Prevalence of Thrombophilia in Women with Spontaneous Pregnancy Loss.

We retrospectively analyzed the records of 145 female patients ages 18 to 50 who were referred to the Thrombosis and Hemostasis Section of the Hematology-Oncology Division at Mt. Sinai Hospital from January 2000 to June 2004 for evaluation of thrombophilia as the etiology of pregnancy loss (PL). Recurrent Pregnancy Loss (RPL) was defined as 2 or more PL in the first trimester of gestation. Women with one or more PL in the second and/or third trimester of gestation or stillbirth, or a combination of above were also analyzed. The following thrombophilic conditions were evaluated: factor V Leiden, prothrombin gene mutation (G20210), antiphospholipid (APL) antibodies and lupus anticoagulant (LAC), homocysteine and functional levels of protein C, S and antithrombin. Of the 145 patients, 20 were excluded from analysis for the following reasons: isolated 1 first trimester PL (15 patients), no verification of antiphospholipid antibodies (4 patients) and insuficient data (1 patient). Of the evaluable patients, 75 (60%) had 2 or more first trimester PL, 14 (11.2%) patients had 1 or more second trimester PL, 2 (1.6%) patients had 1 or more third trimester PL and 24 (19.2%) patients had PL in different trimesters. 70 of the 125 patients (56%) were found to have a thrombophilic condition: 25 had antiphospholipid antibodies, 21 had factor V Leiden (20 heterozygous and 1 homozygous), 16 had prothrombin gene mutation (all heterozygous), 5 had protein S deficiency, 2 had homocysteine level, and 1 had protein C deficiency. We did not identify any patient with antithrombin deficiency. Of the 75 patients with first trimester PL, 36 (48%) were found to have a thrombophilic condition: 18 (50%) had antiphospholipid antibodies, 9 (25) had factor V Leiden (1 homozygous and 8 heterozygous) (17%), 5 (13.8) had heterozygous prothrombin gene mutation (8%), 3 (8.3%) had increased homocysteine level and 3 had a low protein S level (8.3%). In summary, we found a thrombophilic condition associated with PL in 56% in this patient population. The majority of patients had recurrent first trimester PL. The most prevalent thrombophilic disorder was the presence of antiphospholipid antibodies, followed by factor V Leiden, prothrombin gene mutation and protein S deficiency and the least common was increased homocysteine level. These results suggest that testing for thrombophilia may be warranted in women with recurrent PL.

Reevaluation of the Incidence of Thromboembolic Complications in Congenital Factor XII Deficiency

SummaryTo further elucidate the debated role of hereditary FXII deficiency as a thrombophilic risk factor this follow-up study on 65 subjects out of 12 Swiss families was undertaken (follow-up: 6 yrs). Fifteen severely FXII deficient subjects (FXII:C < 1%), 35 partially FXII deficient subjects (FXII:C ≥ 1-59%), 10 with normal FXII values (FXII:C ≥ 70%), and 5 non-classifiable subjects (FXII:C ≥ 60-69%) were reevaluated. Eight subjects (4 severely and 3 partially FXII deficient, 1 non-classifiable) were newly enrolled. Four instances of deep vein thrombosis, one superficial vein thrombosis and one myocardial infarction were noted in 2 out of 19 severely FXII deficient subjects during a total life-time period of 866.6 patient-years. In 38 partially FXII deficient subjects (1862.8 patient-years) one ischemic cerebrovascular stroke and one superficial vein thrombosis were recorded in 2 individuals. The 10 subjects with normal FXII values (498.2 patient-years) remained thrombosis-free. One superficial vein thrombosis occurred in an unclassifiable woman. None of the 3 different FXII gene defects revealed in our patients was specifically associated with thromboembolic complications. Kaplan-Meier analysis of thrombosis-free survival suggests that hereditary partial (and probably severe) FXII deficiency does not constitute a thrombophilic condition.

Antiphospholipid Antibodies Accelerate Plasma Coagulation by Inhibiting Annexin-V Binding to Phospholipids: A “Lupus Procoagulant” Phenomenon

The antiphospholipid syndrome is a thrombophilic condition marked by antibodies that recognize anionic phospholipid-protein cofactor complexes. We recently reported that exposure to IgG fractions from antiphospholipid patients reduces the level of annexin-V, a phospholipid-binding anticoagulant protein, on cultured trophoblasts and endothelial cells and accelerates coagulation of plasma exposed to these cells. Therefore, we asked whether antiphospholipid antibodies might directly reduce annexin-V binding to noncellular phospholipid substrates. Using ellipsometry, we found that antiphospholipid IgGs reduce the quantity of annexin-V bound to phospholipid bilayers; this reduction is dependent on the presence of β2-glycoprotein I. Also, exposure to plasmas containing antiphospholipid antibodies reduces annexin-V binding to phosphatidyl serine-coated microtiter plates, frozen thawed washed platelets, activated partial thromboplastin time (aPTT) reagent and prothrombin time reagent and reduces the anticoagulant effect of the protein. These studies show that antiphospholipid antibodies interfere with the binding of annexin-V to anionic phospholipid and with its anticoagulant activity. This acceleration of coagulation, due to reduced binding of annexin V, stands in marked contrast to the “lupus anticoagulant effect” previously described in these patients. These results are the first direct demonstration of the displacement of annexin-V and the consequent acceleration of coagulation on noncellular phospholipid surfaces by antiphospholipid antibodies. © 1998 by The American Society of Hematology.

Antiphospholipid Antibodies Accelerate Plasma Coagulation by Inhibiting Annexin-V Binding to Phospholipids: A “Lupus Procoagulant” Phenomenon

The antiphospholipid syndrome is a thrombophilic condition marked by antibodies that recognize anionic phospholipid-protein cofactor complexes. We recently reported that exposure to IgG fractions from antiphospholipid patients reduces the level of annexin-V, a phospholipid-binding anticoagulant protein, on cultured trophoblasts and endothelial cells and accelerates coagulation of plasma exposed to these cells. Therefore, we asked whether antiphospholipid antibodies might directly reduce annexin-V binding to noncellular phospholipid substrates. Using ellipsometry, we found that antiphospholipid IgGs reduce the quantity of annexin-V bound to phospholipid bilayers; this reduction is dependent on the presence of β2-glycoprotein I. Also, exposure to plasmas containing antiphospholipid antibodies reduces annexin-V binding to phosphatidyl serine-coated microtiter plates, frozen thawed washed platelets, activated partial thromboplastin time (aPTT) reagent and prothrombin time reagent and reduces the anticoagulant effect of the protein. These studies show that antiphospholipid antibodies interfere with the binding of annexin-V to anionic phospholipid and with its anticoagulant activity. This acceleration of coagulation, due to reduced binding of annexin V, stands in marked contrast to the “lupus anticoagulant effect” previously described in these patients. These results are the first direct demonstration of the displacement of annexin-V and the consequent acceleration of coagulation on noncellular phospholipid surfaces by antiphospholipid antibodies. © 1998 by The American Society of Hematology.