Soluble thrombomodulin levels among women with a history of recurrent pregnancy loss, with or without antiphospholipid antibodies.

The endothelial cells produce substances whose elevated plasma levels acquire predictive value for the development of events. For instance, soluble thrombomodulin (sTM) levels evidence endothelial cell injury. Under specific clinical conditions the levels of sTM are raised, such as in patients with certain autoimmune disorders, pre-eclampsia or antiphospholipid syndrome. The levels of sTM, as an endothelial injury marker, were evaluated in 65 women with a history of recurrent pregnancy loss (12 with autoimmune disorders, 19 pregnant women and nine with a history of gestational hypertension or pre-eclampsia or eclampsia); 13 of them had antiphospholipid antibodies. sTM levels could be used as a predictor of pregnancy loss in future prospective studies. We compared those levels with the levels found in control groups without recurrent pregnancy loss (20 healthy women and 14 women with autoimmune disorder). There were no statistically significant differences (P = 0.729) in the levels of sTM between the recurrent pregnancy loss group (31.1 ng/ml) and the healthy control group (31.4 ng/ml) or between the different subgroups with recurrent pregnancy loss (P = 0.873) and the healthy control group or the control group with autoimmune disorder (28.0 ng/ml). There were no statistically significant differences (P = 0.605) in the levels of sTM among the patients with recurrent pregnancy loss, with or without moderate or high antiphospholipid antibodies (32.0 versus 23.3 ng/ml). Consequently, the levels of sTM would not seem to be a useful tool, as an endothelial injury marker, in women with a history of recurrent pregnancy loss with or without antiphospholipid antibodies.

Endothelial markers and HIV infection in the era of highly active antiretroviral treatment.

Many circumstances can induce activation and/or injury of the endothelium that plays a role in the development of vascular complications. Raised plasma levels of endothelial markers such as von Willebrand factor (vWF), soluble thrombomodulin (sTM) and soluble vascular cell adhesion molecule-1 (sVCAM-1) have a prognostic and/or diagnostic value. Human immunodeficiency virus-infected patients (HIV+) have a clustering of conditions that activate or injure the endothelium. Highly active antiretroviral treatment produces adverse effects such as dyslipemia, insulin resistance (IR) and body fat changes (named lipodystrophy syndrome) which may contribute to aggravate their endothelial perturbation. The aim of this study was to measure lipid profile, insulin resistance status, and endothelial markers in 38 HIV+ naive of antiretroviral treatment and 63 HIV+ under highly active antiretroviral treatment (33 with lipodystrophy syndrome and 30 without it). Body fat distribution was also evaluated by dual-energy X-ray absorptiometry (DEXA) analysis. Thirty-one HIV negative subjects were used as controls. We looked for association between variables. Insulin resistance status was a common finding in the four groups. Lipodystrophic patients presented an atherothrombotic lipid profile [elevated levels of triglycerides (TG), low-density lipoprotein cholesterol (LDL-chol) and apolipoprotein-B (APO-B)] and a strong loss of fat in legs and arms (lipoatrophy). All endothelial markers evaluated in our naive patients were higher as compared to control group. sVCAM-1 in HIV+ under therapy without lipodystrophy syndrome showed significantly decreased levels as compared to naive group (487 vs. 666 ng/ml) and vWF and sTM tended to diminish although they did not show a significant difference (130% vs. 170%, 41 vs. 45 ng/ml, respectively). Lipodystrophic patients showed a tendency to increased levels of endothelial activation markers (sVCAM-1: 500 ng/ml and vWF: 154%) together with significantly increased levels of an endothelial injury marker (sTM: 50 ng/ml) with respect to HIV+ under therapy without lipodystrophy syndrome. Plasma levels of sTM, as an endothelial injury marker, correlated with peripheral lipoatrophy (rho = -0.357) in lipodystrophic patients. In conclusion, despite the beneficial immunology effect of highly active antiretroviral treatment and the apparent decrease in the endothelial perturbation, the patients who develop lipodystrophy present altered endothelial markers and other risk factors, such as IR and dyslipemia, which turn them into a high atherothrombotic risk group.

Viral load and disease progression as responsible for endothelial activation and/or injury in human immunodeficiency virus-1-infected patients.

The endothelium participates in haemostasis, inflammation, blood pressure regulation and other physiological systems. Consequently, endothelial dysfunction has been related to hypertension, thrombosis and atherosclerosis. Both von Willebrand factor (vWF) and tissue-type plasminogen activator (t-PA) are synthesized by the endothelium and their plasma levels increased during endothelium activation or injury. So far, they are well-known markers of endothelial cell function. Many circumstances activate or damage the endothelium, such as viruses, bacterium and inflammation. Circulating vWF and t-PA were studied in 92 unselected human immunodeficiency virus-1 (HIV-1)-infected patients [27 patients with and 65 patients without acquired immunodeficiency syndrome (AIDS)] and correlated with plasma levels of pro-inflammatory cytokines (tumour necrosis factor-alpha, interleukin-6), viral load, CD4 T-cell count and infectious status. HIV-1-infected patients had significantly higher plasma levels of vWF (152 versus 90%), tumour necrosis factor-alpha (31.3 versus 9.0 pg/ml) and interleukin-6 (3.5 versus 1.9 pg/ml) but not t-PA (5.9 versus 4.2 ng/ml) than the control group. These two endothelial markers correlated significantly with viral load and interleukin-6 levels in HIV-1-infected patients. The highest levels of vWF and t-PA were found in patients with AIDS. In conclusion, endothelial cell perturbation is present in HIV infection and may be a consequence of different mechanisms such as viral load, cytokines and advanced diseases.

Baja prevalencia de anticuerpos antifosfolípidos autoinmunes en enfermedades hepáticas / Low prevalence of autoimmune antiphospholipid antibodies in hepatic diseases

Antiphospholipid antibodies (aPL) have been associated with different diseases. They are defined as a large family of immunoglobulins (Ig) of either alloantibodies or autoantibodies. The autoimmune antibodies are associated with venous and/or arterial thrombosis, thrombocytopenia and recurrent fetal loss in the so-called antiphospholipid syndrome or in systemic lupus erythematosus. These antibodies are directed against proteins or phospholipid-protein complexes. On the contrary, antiphospholipid antibodies (alloantibodies) which are found in infectious diseases sera (syphilis, HIV, and other viral diseases), disappear with illness remission and are directed to phospholipids alone (particularly cardiolipin) and are not associated with thrombosis or recurrent fetal loss. However, the role and type of aPL found during hepatic diseases is still unclear. To investigate the prevalence of autoimmune aPL (IgG and IgM) during different hepatic diseases, we have studied 128 patients with hepatitis C virus, hepatitis B virus and hepatic autoimmune diseases without treatment as well as 40 healthy control subjects. We have used a specific ELISA kit, that uses a mixture of phospholipid instead of cardiolipin alone, and allows a better detection of aPL of the autoimmune type. Our results show that autoimmune aPL are not significantly increased in viral hepatic diseases (2%) or autoimmune diseases of the liver (3%) when compared to the control group (0%).