[Lipoprotein(a), its autoantibodies, and circulating T lymphocyte subpopulations as independent risk factors for coronary artery atherosclerosis]

Association of Lipoprotein(a) with peri-coronary inflammation in persons with and without HIV infection

BACKGROUND

Persons with human immunodeficiency virus (HIV) (PWH) have an increased risk of developing cardiovascular disease (CVD) compared to persons without HIV (PWoH). Lipoprotein(a) [Lp(a)] is a known atherosclerotic risk factor in PWoH, but there are no studies investigating Lp(a) and peri-coronary inflammation.

OBJECTIVE

To investigate whether Lp(a) is associated with peri-coronary inflammation as assessed by the fat attenuation index (FAI) and activated monocytes and T lymphocytes in PWH and PWoH.

METHODS

We measured plasma levels of Lp(a) at study entry in 58 PWH and 21 PWoH without CVD and who had FAI measurements. Associations of Lp(a) with FAI values of the right coronary artery (RCA) and left anterior descending artery were evaluated using multivariable regression models adjusted for potential confounders. Correlations between Lp(a) levels and systemic inflammatory markers and immune cell subsets were examined.

RESULTS

Lp(a) was associated with greater peri-coronary inflammation among PWH compared to PWoH (β=1.73, P=0.019) in the RCA, in adjusted models. Significant correlations were observed with certain inflammatory markers (tumor necrosis factor receptor [TNFR]-I, b=0.295, P<0.001; TNFR-II, b=0.270, P=0.002; high-sensitivity C-reactive protein, b=0.195, P=0.028). Significant correlations were found between Lp(a) levels and several markers of monocyte activation: CD16 -CD163+ (b= -0.199, P=0.024), and CD16 -DR+ MFI (b= -0.179, P=0.042) and T cell subset CD38+CD4+ TEMRA (b= 0.177, P= 0.044).

CONCLUSIONS

Lp(a) was associated with greater peri-coronary inflammation in the RCA in PWH compared to PWoH, as well as with select systemic inflammatory markers and specific subsets of immune cells in peripheral circulation.

Association of lipoprotein(a) with aortic dissection

Background

Lipoprotein(a) [Lp(a)] is associated with coronary atherosclerotic heart disease, aortic stenosis, stroke, and heart failure. We aimed to determine the relationship between Lp(a) and aortic dissection (AD).

Methods

Two hundred patients with AD were included in our case group. The control group consisted of 200 non‐AD people who were age‐ (±5 years) and gender‐matched to the case group. Data were collected retrospectively, including hypertension, smoking, coronary artery disease, diabetes mellitus, Lp(a), total cholesterol, triglyceride, low‐density lipoprotein cholesterol, and high‐density lipoprotein cholesterol. The association between Lp(a) and AD was studied using univariate and multivariate logistic regression analysis.

Results

Patients with AD had greater median Lp(a) concentrations than non‐AD people (152.50 vs. 81.75 mg/L). Lp(a) was associated with AD in a multivariate logistic regression analysis (odds ratio, 8.03; 95% confidence interval, 2.85–22.62), comparing those with Lp(a) quartile 4 with those with Lp(a) quartile 1. Stratified analysis showed that this relationship was observed in both men and women, as well as in older and younger individuals.

Conclusions

High levels of Lp(a) are strongly associated with AD, independent of other cardiovascular risk factors.

The Association of Lipoprotein(a) and Circulating Monocyte Subsets with Severe Coronary Atherosclerosis

Background and aims: Chronic inflammation associated with the uncontrolled activation of innate and acquired immunity plays a fundamental role in all stages of atherogenesis. Monocytes are a heterogeneous population and each subset contributes differently to the inflammatory process. A high level of lipoprotein(a) (Lp(a)) is a proven cardiovascular risk factor. The aim of the study was to investigate the association between the increased concentration of Lp(a) and monocyte subpopulations in patients with a different severity of coronary atherosclerosis. Methods: 150 patients (124 males) with a median age of 60 years undergoing a coronary angiography were enrolled. Lipids, Lp(a), autoantibodies, blood cell counts and monocyte subpopulations (classical, intermediate, non-classical) were analyzed. Results: The patients were divided into two groups depending on the Lp(a) concentration: normal Lp(a) < 30 mg/dL (n = 82) and hyperLp(a) ≥ 30 mg/dL (n = 68). Patients of both groups were comparable by risk factors, autoantibody levels and blood cell counts. In patients with hyperlipoproteinemia(a) the content (absolute and relative) of non-classical monocytes was higher (71.0 (56.6; 105.7) vs. 62.2 (45.7; 82.4) 10³/mL and 17.7 (13.0; 23.3) vs. 15.1 (11.4; 19.4) %, respectively, p < 0.05). The association of the relative content of non-classical monocytes with the Lp(a) concentration retained a statistical significance when adjusted for gender and age (r = 0.18, p = 0.03). The severity of coronary atherosclerosis was associated with the Lp(a) concentration as well as the relative and absolute (p < 0.05) content of classical monocytes. The high content of non-classical monocytes (OR = 3.5, 95% CI 1.2–10.8) as well as intermediate monocytes (OR = 8.7, 2.5–30.6) in patients with hyperlipoproteinemia(a) were associated with triple-vessel coronary disease compared with patients with a normal Lp(a) level and a low content of monocytes. Conclusion: Hyperlipoproteinemia(a) and a decreased quantity of classical monocytes were associated with the severity of coronary atherosclerosis. The expansion of CD16+ monocytes (intermediate and non-classical) in the presence of hyperlipoproteinemia(a) significantly increased the risk of triple-vessel coronary disease.

Lipoprotein(a), Immunity, and Inflammation in Polyvascular Atherosclerotic Disease

Background and aims: lipoprotein(a) (Lp(a)) is a genetically determined risk factor for coronary artery disease and its complications, although data on the association with other vascular beds and the severity of atherosclerosis is limited. The aim of this study was to evaluate the association of atherosclerosis of various vascular beds with Lp(a), as well as its autoantibodies and generalized inflammatory markers. Material and methods: this study included 1288 adult patients with clinical and imaging examination of three vascular beds (coronary, carotid, and lower limb arteries). Patients were categorized according to the number of affected vascular beds (with at least one atherosclerotic stenosis ≥50%): 0 (n = 339), 1 (n = 470), 2 (n = 315), 3 (n = 164). We assessed blood cell count, lipid profile, C-reactive protein, circulating immune complexes, Lp(a), and its autoantibodies. Results: the number of affected vascular beds was associated with an increasing level of Lp(a) and a lower level of IgM autoantibodies to Lp(a). Hyperlipoproteinemia(a) (Lp(a) ≥ 30 mg/dL) was detected more frequently in patients with atherosclerosis. In logistic regression analysis adjusted for age, sex, hypertension, type 2 diabetes, and smoking, an elevated Lp(a) level was independently associated with stenotic atherosclerosis and lesion severity. There was a positive association of the number of affected vascular beds with C-reactive protein (r = 0.21, p < 0.01) and a negative association with circulating immune complexes (r = −0.29, p < 0.01). The neutrophil-to-lymphocyte ratio was significantly higher and the lymphocyte-to-monocyte ratio was significantly lower in patients with atherosclerosis compared to the controls (p < 0.01). Conclusion: Lp(a), C-reactive protein, circulating immune complexes, and neutrophil-to-lymphocyte ratio are associated with the stenotic atherosclerosis of different vascular beds. Lp(a) levels increase and IgM autoantibodies to Lp(a) decrease with the number of affected vascular beds.

Thoracic Aortic Aneurysm and Factors Affecting Aortic Dissection

This study is aimed at investigating the relationship between inflammation, the number of vasa vasorum, and the presence of lipoprotein (a) [Lp(a)] in the aortic aneurysm wall, as well as the relationships of these pathological processes with the development of aneurysm wall dissection. To that end, we examined segments of aortic aneurysm wall, consisting of intima, media, and adventitia, collected from patients during aneurysm prosthetics intervention. The material was collected from 23 men and eight women aged from 33 to 69 years. Monoclonal antibodies to Lp(a), markers of monocytes and macrophages (CD68), T cells (CD3, CD4, and CD8), von Willebrand factor, endothelium NO synthase, and smooth muscle α-actin were used for morphological and morphometric investigation. The present study demonstrated that Lp(a) is not often found in biopsies of patients with thoracic aortic aneurysm. Morphological and morphometric investigation shows the connection of aortic dissection with the process of damage to its wall caused by inflammatory infiltrates, medianecroses, and the appearance of newly formed vasa vasorum in media.

[Lipoprotein(а) Level, Apolipoprotein(а) Polymorphism аnd Autoаntibodies Against Lipoprotein(а) in Patients with Stenotic Cаrotid Atherosclerosis]

Аim. Comparative assessment of respiratory indicators according to multifunctional monitoring (PFM) with the recommended standard for a complete polysomnographic study and an assessment of the effect of blood pressure (BP) measurements in PFM on sleep quality. Triаls on the аssociаtion of Lp(а) and cаrotid аtherosclerosis аre limited. The аim of the study wаs to investigаte the аssociаtion of Lp(а), аpolipoprotein(а) [apo(а)] polymorphism аnd аutoаntibodies to Lp(а) with stenotic (≥50%) cаrotid аtherosclerosis in dependence on CHD presence. Materials and methods. The study included 785 pаtients аt the аge from 21 to 92 with dаtа of instrumentаl exаmination of coronаry, cаrotid аnd lower limbs аrteries. Stenotic cаrotid аtherosclerosis wаs diаgnosed in 447 pаtients who were divided into two groups depending on presence (n=344) or аbsence (n=103) of CHD. The control group comprised of 338 pаtients without stenotic аtherosclerosis of coronаry, cаrotid аnd lower limbs аrteries. In the blood serum of pаtients levels of Lp(а), аutoаntibodies to Lp(а) were determined аnd аlso аpo(а) phenotyping wаs conducted. Results. There were more mаles, higher аverаge аge аnd frequency of hypertension, type 2 diаbetes mellitus, smoking, Lp(а) concentrаtion (mediаn [interquаrtile rаnge]): 30 [11; 63] vs. 14 [5; 30] mg/dl, p&lt;0.01) in the group with stenotic cаrotid аtherosclerosis in compаrison with control group. Besides, Lp(а) level wаs higher in CHD subgroup thаn in pаtients with stenotic cаrotid аtherosclerosis without CHD: 32 [12; 72] vs. 24 [8; 50] mg/dl, respectively, p=0.01. Elevаted (≥30 mg/dl) Lp(а) level, low moleculаr weight аpolipoprotein(а) [(LMW аpo(а)] phenotype were аssociаted with stenotic cаrotid аtherosclerosis (odds rаtio (OR) 2.9; 95% confidence intervаl (CI) 2.1-4.0, p&lt;0.01 аnd OR 2.3; 95% CI 1.6-3.4, p&lt;0.01, respectively). Logistic regression аnаlysis showed independent аssociаtion of elevаted Lp(а) level аnd LMW аpo(а) phenotype with stenotic cаrotid аtherosclerosis both in the presence аnd absence of CHD. The level of IgM аutoаntibodies to Lp(а) wаs higher in control group thаn in pаtients with stenotic cаrotid аtherosclerosis, p=0.02. Conclusion The level of Lp(a) ≥30 mg/dl and low molecular weight phenotype of aprotein(a) are predictors of stenotic atherosclerosis CA, regardless of the presence of coronary heart disease and other risk factors, while a reverse relationship was found between the level of autoantibodies of the IgM class against Lp(a) and the severity of atherosclerosis CA.

The Association of Lipoprotein(a), Apolipoprotein(a) Phenotypes and Autoantibodies to Lipoprotein(a) With Lower Extremity Artery Disease

AIM

Lipoprotein(a) [Lp(a)] and low molecular weight (LMW) apolipoprotein(a) [apo(a)] phenotype are risk factors of сoronary heart disease and stroke. Data about the role of Lp(a) and phenotypes apo(a) in the development of lower extremity artery disease (LEAD) is scarce. The aim of our study was to assess the association of Lp(a), apo(a) phenotypes and autoantibodies to apolipoprotein B100 (apoB100) lipoproteins with LEAD.

MATERIALS AND METHODS

The study included 622 patients (386 male and 236 female, average age 61±12 years), examined in the Department of Atherosclerosis of National Medical Research Center of Cardiology. Patients were divided into 2 groups: the main group included 284 patients with LEAD, 338 patients without significant atherosclerosis of coronary, carotid and lower limbs arteries formed the control group. LEAD was diagnosed as atherosclerotic lesions with at least one stenosis of low limb artery ≥50 % and ankle-brachial index ≤0.9. The concentration of Lp(a), lipids was measured in blood serum of all the patients, level of autoantibodies to apoB100 lipoproteins was measured in 247 patients, and apo(a) phenotypes were determined in 389 patients.

RESULTS

Patients with LEAD were older, were more frequently male, and had a greater prevalence of risk factors including hypertension, type 2 diabetes, smoking than the control group patients (p&lt;0.001 in all the cases). The level of Lp(a) was significantly higher in the main group compared to control group: 35 [14; 67] mg / dl vs. 14 [5; 32] mg / dl, p&lt;0,001. ROC analysis demonstrated that the level of Lp(a) ≥26 mg / dl was associated with LEAD (sensitivity 61 %, specificity 70 %). The prevalence of Lp(a) ≥26 mg / dl and LMW apo(a) phenotype were higher in the main group in comparison with the control group: 61 % vs. 30 % and 48 % vs. 26 % respectively (p&lt;0.001 in the both cases). The odds ratio of LEAD in the presence of Lp(a) ≥26 mg / dl was 3.7 (95 % confidence interval (CI), 2.6-5.1, p&lt;0.001) and in the presence of LMW apo(a) phenotype was 2.6 (95 % CI, 1.7-4.0, p&lt;0.001). In logistic regression analysis adjusted for age, sex, hypertension, smoking, diabetes, both Lp(a) and LMW apo(a) phenotype were independent predictors of LEAD when included separately. The level of IgM autoantibodies to Lp(a) was significantly higher in the control group compared to the patients with LEAD (p=0.01). Concentration of IgG autoantobodies to Lp(a) and LDL in the plasma did not differ essentially in the both groups.

CONCLUSION

The level of Lp(a) ≥26 mg / dl and LMW apo(a) phenotype are independent predictors of LEAD, whereas the contribution of autoantobodies to Lp(a) in LEAD development is controversial.