Lipoprotein (a) and apolipoprotein (a) in primary antiphospholipid syndrome

Impact of hypertension and hyperhomocysteinemia on arterial thrombosis in primary antiphospholipid syndrome

The aim of this study was to evaluate traditional risk factors for coronary artery disease (CAD), homocysteine, anti-oxidized low-density lipoprotein (anti-oxLDL), anti-lipoprotein lipase (anti-LPL) and endothelin-1 (ET-1) in patients with primary anti-phospholipid syndrome (APS), furthermore verify possible association among these variables and arterial thrombosis. Thirty-eight women with primary APS and 30 age-and-sex-matched controls were evaluated. Patients presented higher-LDL and triglycerides levels and lower-HDL levels than controls. Anti-LPL antibodies were not detected in both groups. The mean number of risk factors was higher in patients than in controls ( P = 0.030). Anti-oxLDL antibodies, homocysteine and ET-1 mean levels were similar between groups, but abnormal homocysteine levels were found only among primary APS patients ( P = 0.031). Hypertension and the presence of at least one risk factor for CAD were more prevalent in patients with arterial involvement than those without. Homocysteine levels and mean number of risk factors for CAD were significantly higher in patients with arterial thrombosis than controls. In a multivariate analysis hypertension was the only independently associated with arterial thrombosis (OR 14.8, 95% CI = 2.1—100.0, P = 0.006). This study showed that in primary APS patients other risk factors besides anti-phospholipid antibodies contribute for the occurrence of arterial events and the most important factor was hypertension. Lupus (2007) 16, 782—787.

A Systematic Literature Review of the Association of Lipoprotein(a) and Autoimmune Diseases and Atherosclerosis

Objective. To investigate the association of lipoprotein(a) and atherosclerosis-related autoimmune diseases, to provide information on possible pathophysiologic mechanisms, and to give recommendations for Lp(a) determination and therapeutic options. Methods. We performed a systematic review of English language citations referring to the keywords "Lp(a)" AND "autoimmune disease" AND "atherosclerosis," "Lp(a)" AND "immune system" OR "antiphospholipid (Hughes) syndrome (APS)" OR "rheumatoid arthritis" OR "Sjögren's syndrome" OR "systemic lupus erythematosus" OR "systemic sclerosis" OR "systemic vasculitis" published between 1991 and 2011 using Medline database. Results. 22 out of 65 found articles were identified as relevant. Lp(a) association was highest in rheumatoid arthritis (RA), followed by systemic lupus erythematosus (SLE), moderate in APS and lowest in systemic sclerosis (SSc). There was no association found between Lp(a) and systemic vasculitis or Sjögren's syndrome. Conclusion. Immune reactions are highly relevant in the pathophysiology of atherosclerosis, and patients with specific autoimmune diseases are at high risk for CVD. Elevated Lp(a) is an important risk factor for premature atherosclerosis and high Lp(a) levels are also associated with autoimmune diseases. Anti-Lp(a)-antibodies might be a possible explanation. Therapeutic approaches thus far include niacin, Lp(a)-apheresis, farnesoid x-receptor-agonists, and CETP-inhibitors being currently under investigation.

Potential Markers of Arterial and/or Venous Thromboses and their Complications in Primary Antiphospholipid Syndrome

Antiphospholipid syndrome is characterized by venous or arterial thromboses and/or recurrent abortions accompanied by antiphospholipid antibodies and it can be primary (PAPS) or secondary (SAPS) to another disease. Arterial thromboses are less common than venous and most frequently they manifest as ischemia or infarction. Venous thromboses are usually multiple and bilateral and the most common complication of venous thromboses are pulmonary emboli. Considering that laboratory diagnosis of PAPS is currently based on persistently positive aCL, aβ2gpl and/or LA tests, and that neither one of those tests can discriminate between PAPS patients with arterial or venous thromboses or their complications, the aim of this study was to investigate the diagnostical significance of the determination of apo(a), oxLDL, anti-oxLDL antibodies, antianxA5 antibodies, hsCRP, C3 and C4 complement components and HPT for discrimination between PAPS patients with diverse clinical manifestations. Considering that elevated oxLDL and anti-oxLDL antibodies concentrations were found in PAPS patients, and also in subgroups of PAPS patients with MI or PE, it can be concluded that those parameters represent additional risk factors which together with other factors may lead to thromboses and their complications in PAPS. Regarding the fact that C3 and C4 concentrations were decreased in PAPS patients and that a positive correlation was found between hsCRP and C3 concentrations, this finding could indicate potential roles of these parameters as markers of atherosclerosis, which represents the leading cause of morbidity and mortality. HPT and apo(a) concentrations are not independent risk factors for MI in PAPS because lower levels were found in those patients in comparison to MI survivors without PAPS. No significant correlation of anti-anxA5 antibodies and the presence of arterial or venous thromboses or their complications was found, but increased concentrations of the IgG isotype of those antibodies could be a marker for recurrent abortions in PAPS, although this finding should be further investigated on a larger number of patients with this clinical finding. Determination of hsCRP in PAPS patients could not be an adequate parameter which would provide discrimination between patients with increased risk for development and/or recurrence of venous and/or arterial thromboses, nor for their complications, because no statistically significant difference in concentrations of this parameter was found among PAPS, IM, PE and SLE patients who were included in this study.