A prospective diagnostic accuracy study evaluating rotational thromboelastometry and thromboelastography in 100 patients with von Willebrand disease.

INTRODUCTION: Rotational thromboelastometry (ROTEM® ) and thromboelastography (TEG® ) are increasingly used in the perioperative and emergency assessment of bleeding tendencies. The diagnostic value of ROTEM and TEG for von Willebrand disease (VWD) remains to be established. AIM: To investigate whether ROTEM and TEG can discriminate patients with VWD from healthy controls. METHODS: Rotational thromboelastometry and TEG whole blood coagulation profiles were compared between VWD patients (n = 100) and healthy controls (n = 89). Measures of diagnostic accuracy were calculated, including sensitivity, specificity and receiver operating characteristic (ROC) curve. RESULTS: Prolonged TEG R-time had a positive and negative predictive value (PPV, NPV) of 0.84 and 0.68 respectively. TEG clotting index (CI) had a PPV of 1.00 and an NPV of 0.60. Both R-time and CI had a high specificity and accurately discriminated VWD patients from healthy controls, with an ROC area under the curve of 0.85 and 0.99 respectively. In multivariate analysis, low FVIII levels, but not von Willebrand factor (VWF) antigen or activity, determined hypocoagulable TEG R (R2 = 0.35) and CI levels (R2 = 0.51). The ROTEM coagulation profiles of VWD patients did not differ from healthy controls. CONCLUSIONS: Thromboelastography R and CI accurately discriminated VWD patients from healthy controls, partly through the detection of low FVIII levels. The test's performance may be improved through adjustment of the test thresholds to a local reference population. Both intrinsic pathway-activated (INTEM) and tissue factor pathway-activated (EXTEM) ROTEM were of limited diagnostic value in VWD.

Predicting venous thrombosis in women using a combination of genetic markers and clinical risk factors.

BACKGROUND: Family history of venous thromboembolism (VTE) has been suggested to be more useful in risk assessment than thrombophilia testing. OBJECTIVES: We investigated established genetic susceptibility variants for association with VTE and evaluated a genetic risk score in isolation and combined with known trigger factors, including family history of VTE. PATIENTS/METHOD: A total of 18 single nucleotide polymorphisms (SNPs) selected from the literature were genotyped in 2835 women participating in a Swedish nationwide case-control study (the ThromboEmbolism Hormone Study [TEHS]). Association with VTE was assessed by odds ratios (ORs) with 95% confidence interval (CI) using logistic regression. Clinical and genetic predictors that contributed significantly to the fit of the logistic regression model were included in the prediction models. SNP-SNP interactions were investigated and incorporated into the models if found significant. Risk scores were evaluated by calculating the area under the receiver-operating characteristics curve (AUC). RESULTS: Seven SNPs (F5 rs6025, F2 rs1799963, ABO rs514659, FGG rs2066865, F11 rs2289252, PROC rs1799810 and KNG1 rs710446) with four SNP-SNP interactions contributed to the genetic risk score for VTE, with an AUC of 0.66 (95% CI, 0.64-0.68). After adding clinical risk factors, which included family history of VTE, the AUC reached 0.84 (95% CI, 0.82-0.85). The goodness of fit of the genetic and combined scores improved when significant SNP-SNP interaction terms were included. CONCLUSION: Prediction of VTE in high-risk individuals was more accurate when a combination of clinical and genetic predictors with SNP-SNP interactions was included in a risk score.

Studies of microparticles in patients with the antiphospholipid syndrome (APS).

OBJECTIVES: To study circulating platelet, monocyte and endothelial microparticles (PMPs, MMPs and EMPs) in patients with antiphospholipid syndrome (APS) in comparison with healthy controls. MATERIAL AND METHOD: Fifty-two patients with APS and 52 healthy controls were investigated. MPs were measured on a flow cytometer (Beckman Gallios) and defined as particles sized < 1.0 µm, negative to phalloidin, positive to lactadherin and positive to either CD42a (PMPs), CD144 (EMPs) or CD14 (MMPs). Exposure of CD142 (TF) was measured on CD144 positive MPs. RESULTS: Total number of MPs (i.e. lactadherin positive particles) was higher in APS patients versus controls (p < 0.001). An increased number of EMPs (p < 0.001), increased TF-positive EMPs (p < 0.001) and increased MMPs (p < 0.001) were also observed. PMP numbers did not differ between the groups. None of the MP types differed in numbers between obstetric and thrombotic APS patients. CONCLUSION: We observed a high number of EMPs expressing TF in APS patients. The numbers of MMPs and total EMPs were also higher as compared with healthy controls but in contrast to previous reports, the number of PMPs did not differ between groups.

[Celiac disease can be associated with severe neurological symptoms. Analysis of gliadin antibodies should be considered in suspected cases]. / Celiaki kan vara förenad med allvarliga neurologiska symtom. Gliadinantikroppsanalys bör övervägas i oklara fall.

Celiac disease can be associated with a wide spectrum of neurological and psychiatric symptoms (cerebellar ataxia, neuromuscular manifestations, epilepsy, dementia), even in the absence of malabsorption or gastrointestinal symptoms. The case of a 72-year-old man with a rapidly progressive, lethal encephalopathy secondary to celiac disease is reported, together with a review of documented neurological symptoms in celiac disease. The aetiology of these neurological symptoms is unknown, although immunological mechanisms are suspected.

T-cell recognition of lipid peroxidation products breaks tolerance to self proteins.

Peroxidation of polyunsaturated fatty acids in lipoproteins and cell membrane phospholipids occurs in many situations in the body, both under normal and pathological conditions. Low-density lipoprotein is particularly prone to oxidation and is believed to be a pathogenetic component in atherogenesis. Both antibody responses and T-cell responses to oxidatively modified lipoproteins have been demonstrated in humans as well as in animal models. However, little is known about how these responses arise or how T cells recognize these antigens. In the present study, mice were immunized with homologous albumin covalently modified with a series of defined aldehydes which are known to be generated during lipid peroxidation. T-cell hybridomas from immunized animals demonstrated major histocompatibility complex-restricted and protein sequence-dependent responses to modified albumin, but not to native albumin. In addition to the response to modified epitopes, some aldehyde modifications resulted in strong antibody responses also to the non-modified protein. This T-cell-dependent break of tolerance constitutes a novel pathway for induction of autoimmunity by lipid peroxidation. The findings have implications in many situations where lipid peroxidation products are generated, including atherosclerosis and inflammatory and infectious diseases.

Expression of the macrophage scavenger receptor in atheroma. Relationship to immune activation and the T-cell cytokine interferon-gamma.

Scavenger receptors mediate internalization of modified lipoproteins and foam cell transformation of monocyte-derived cytokines. We investigated macrophage scavenger receptor (MSR) expression in monocyte-macrophages from human peripheral blood and in atherosclerotic lesions and analyzed its relationship to T lymphocytes and immunoregulatory cytokines by immunohistochemistry and polymerase chain reaction (PCR). Antibodies specific for the two MSR isoforms were generated by immunizing rabbits with isoform-specific synthetic peptides conjugated to keyhole limpet hemocyanin. In human atherosclerotic plaques, these antibodies stained macrophages and foam cells in a pattern that corresponded to the distribution of the macrophage marker CD68. CD3-positive T cells and alpha-actin-positive smooth muscle cells exhibited no reactivity to the anti-MSR antibodies. The frequency of cells stained with antibodies to MSR type I was equal to that of cells stained for type II, suggesting that most macrophages coexpress both isoforms. Reverse transcription (RT)-PCR analysis confirmed that both MSR isoforms were expressed in all plaques examined. There was, however, a tendency toward a lower immunohistochemical staining intensity for MSR type I and a decreased number of lipid-rich foam cells in T cell-rich areas. The mRNAs for interleukin-2 and interferon-gamma, two major products of activated T cells, were detected by RT-PCR in all plaques tested. This indicates that activation of T lymphocytes occurs in atherosclerotic plaques. Since interferon-gamma downregulates MSR expression, these observations suggest a potential mechanism for local regulation of MSR expression in the atherosclerotic plaque.