Lipoprotein apheresis affects the concentration of extracellular vesicles in patients with elevated lipoprotein (a)

Lipoprotein apheresis (LA) is a therapeutic option for hyperlipoproteinemia(a) (hyper-Lp(a)) and atherosclerotic cardiovascular disease (ASCVD). LA improves blood rheology, reduces oxidative stress parameters and improves endothelial function. The underlying molecular mechanisms of LA beneficial effects are unknown, but it has been suggested that LA exhibits multiple activities beyond simply removing lipoproteins. We hypothesized that LA removes not only lipoproteins, but also extracellular vesicles (EVs). To test this hypothesis, we performed a prospective study in 22 patients undergoing LA for hyper-Lp(a) and ASCVD. Different EVs subtypes were measured before and directly after LA, and after 7 days. We used calibrated flow cytometry to detect total particle concentration (diameter >  ~ 100 nm), total lipoproteins concentration (diameter > 200 nm, RI > 1.51), total EV concentration (diameter > 200 nm, RI < 1.41), concentrations of EVs derived from erythrocytes (CD235a+; diameter > 200 nm, RI < 1.41), leukocytes (CD45+; diameter > 200 nm, RI < 1.41) and platelets (CD61+, PEVs; diameter > 200 nm, RI < 1.41). LA reduced the concentrations of all investigated EVs subtypes and lipoproteins. Lp(a) concentration was lowered by 64.5% [(58% - 71%); p < 0.001]. Plasma concentrations of EVs > 200 nm in diameter derived from platelets (CD61 +), leukocytes (CD45+) and erythrocytes (CD235a+) decreased after single LA procedure by 42.7% [(12.8-54.7); p = 0.005], 42.6% [(29.7-54.1); p = 0.030] and 26.7% [(1.0-62.7); p = 0.018], respectively, compared to baseline. All EV subtypes returned to the baseline concentrations in blood plasma after 7 days. To conclude, LA removes not only Lp(a), but also cell-derived EVs, which may contribute to LA beneficial effects.

[A case of neonatal-onset type I hyperlipoproteinemia with bloody ascites]

This report presents a case of a male infant, aged 32 days, who was admitted to the hospital due to 2 days of bloody stools and 1 day of fever. Upon admission, venous blood samples were collected, which appeared pink. Blood biochemistry tests revealed elevated levels of triglycerides and total cholesterol. The familial whole genome sequencing revealed a compound heterozygous variation in the LPL gene, with one variation inherited from the father and the other from the mother. The patient was diagnosed with lipoprotein lipase deficiency-related hyperlipoproteinemia. Acute symptoms including bloody stools, fever, and bloody ascites led to the consideration of acute pancreatitis, and the treatment involved fasting, plasma exchange, and whole blood exchange. Following the definitive diagnosis based on the genetic results, the patient was given a low-fat diet and received treatment with fat-soluble vitamins and trace elements, as well as adjustments to the feeding plan. After a 4-week hospitalization, the patient's condition improved and he was discharged. Follow-up showed a decrease in triglycerides and total cholesterol levels. At the age of 1 year, the patient's growth and psychomotor development were normal. This article emphasizes the multidisciplinary diagnosis and treatment of familial hyperlipoproteinemia presenting with symptoms suggestive of acute pancreatitis, including bloody ascites, in the neonatal period.

[Laboratory diagnostics of lipid metabolism disorders]

Clinically, disorders of lipid metabolism often remain without symptoms. Typical skin lesions, however, can be indicative. Secondary hyperlipoproteinemias (HLP) are more common than primary hyperlipoproteinemias; they can (partially) be improved by treating the underlying disease. Basic diagnostics consist of the determination of cholesterol, triglycerides, LDL cholesterol and HDL cholesterol. To exclude secondary HLP, glucose, HbA1C, TSH, transaminases, creatinine, urea, protein and protein in the urine are useful. Since virtually all routine methods for LDL-C are biased by high triglycerides, lipoprotein electrophoresis is indicated for triglycerides above 400 mg/dl (4.7 mmol/l). Primary HLPs have known or yet unknown genetic causes. Primary hyperlipidemias should be taken into consideration especially in young patients with an LDL cholesterol concentration are above 190 mg/dl (4.9 mmol/l) and/or triglycerides above 400 mg/dl (10 mmol/l) and secondary HLP (obesity, alcohol, diabetes mellitus, kidney disease) is excluded. The basic diagnostics is meaningfully extended by the measurement of lipoprotein (a) (Lp(a)). It is indicated in moderate and high risk of vascular disease, progression of atherosclerosis in "well-controlled" LDL cholesterol, familial clustering of atherosclerosis or high Lp(a), evidence for elevated Lp(a) coming from lipoprotein electrophoresis, aortic stenosis and in patients in whom statins have a poor effect. Genetic diagnostics needs to be considered if primary HLP is suspected. It is most frequently conducted for suspected familial hypercholesterolemia and has already been recommended in guidelines.

Novel Pharmacological Therapies for the Management of Hyperlipoproteinemia(a)

Lipoprotein(a) [Lp(a)] is a well-established risk factor for cardiovascular disease, predisposing to major cardiovascular events, including coronary heart disease, stroke, aortic valve calcification and abdominal aortic aneurysm. Lp(a) is differentiated from other lipoprotein molecules through apolipoprotein(a), which possesses atherogenic and antithrombolytic properties attributed to its structure. Lp(a) levels are mostly genetically predetermined and influenced by the size of LPA gene variants, with smaller isoforms resulting in a greater synthesis rate of apo(a) and, ultimately, elevated Lp(a) levels. As a result, serum Lp(a) levels may highly vary from extremely low to extremely high. Hyperlipoproteinemia(a) is defined as Lp(a) levels > 30 mg/dL in the US and >50 mg/dL in Europe. Because of its association with CVD, Lp(a) levels should be measured at least once a lifetime in adults. The ultimate goal is to identify individuals with increased risk of CVD and intervene accordingly. Traditional pharmacological interventions like niacin, statins, ezetimibe, aspirin, PCSK-9 inhibitors, mipomersen, estrogens and CETP inhibitors have not yet yielded satisfactory results. The mean Lp(a) reduction, if any, is barely 50% for all agents, with statins increasing Lp(a) levels, whereas a reduction of 80-90% appears to be required to achieve a significant decrease in major cardiovascular events. Novel RNA-interfering agents that specifically target hepatocytes are aimed in this direction. Pelacarsen is an antisense oligonucleotide, while olpasiran, LY3819469 and SLN360 are small interfering RNAs, all conjugated with a N-acetylgalactosamine molecule. Their ultimate objective is to genetically silence LPA, reduce apo(a) production and lower serum Lp(a) levels. Evidence thus so far demonstrates that monthly subcutaneous administration of a single dose yields optimal results with persisting substantial reductions in Lp(a) levels, potentially enhancing CVD risk reduction. The Lp(a) reduction achieved with novel RNA agents may exceed 95%. The results of ongoing and future clinical trials are eagerly anticipated, and it is hoped that guidelines for the tailored management of Lp(a) levels with these novel agents may not be far off.

[Definition and clinical characteristics of mild hypertension]

Mild hypertension is defined as blood pressure level of 140-159 mmHg systolic and/or 90-99 mmHg diastolic. The patients with blood pressure level of mild hypertension occupy about 60% of total hypertensive patients in Japan, and most of them are free of subjective symptoms except elevated blood pressure. However, some of the patients with mild hypertension develop cardiovascular events, since thay have occasionally cardiovascular damages on this level of blood pressure and several risk factors of cardiovascular diseases such as diabetes mellitus and hyperlipidemia.

Aneurysm of the left main stem leading to anterior wall infarction

We report a case of a woman with a spontaneous dissection of the left main stem leading to a large aneurysm compressing the left coronary artery. The lesion was initially treated with a conventional multicellular stent. However, persistence of the aneurysm required that two polytetrafluoroethylene-covered stents be implanted. Follow-up angiographic and clinical results were excellent.

Effect of hyperlipoproteinemia on functional activity of peritoneal macrophages during tumor growth

The role of hypercholesterolemia as a factor modulating functional activity of macrophages during the growth of syngeneic transplanted 22a hepatoma in mice was studied. Starting from day 21 after inoculation of tumor cells we observed the development of hyperlipoproteinemia paralleled by an increase in macrophage activity parameters. The total serum cholesterol content and production of nitroxide anions by macrophages were in positive correlation on days 14-35 of tumor growth. We hypothesized that the development of hypercholesterolemia at the late stages of some tumor growth is a factor stimulating production of nitrites and 5'-nucleotidase activity.

Partial face-sparing lipodystrophy (Köbberling-Dunnigan syndrome): report of a sporadic case

A sporadic case is presented of a 20-year-old female with partial face-sparing lipodystrophy, also known as the Köbberling-Dunnigan syndrome with the Type 1 clinical phenotype. This disorder affects the limbs and spares the face. The trunk is spared in the Type 1 phenotype but is affected in the Type 2 phenotype. The patient had the associated features of this syndrome including the hyperinsulinaemia, acanthosis nigricans and mildly raised triglycerides, but not diabetes mellitus.

A comparative study of the efficacy of simvastatin and gemfibrozil in combined hyperlipoproteinemia: prediction of response by baseline lipids, apo E genotype, lipoprotein(a) and insulin

Combined hyperlipoproteinemia (CHL) can be difficult to treat because of the heterogeneous nature of the lipoprotein abnormalities. We compared the relative efficacies of simvastatin and gemfibrozil and sought predictors of responsiveness in terms of the baseline lipids and other potential metabolic determinants (plasma insulin, Lp(a) and apo E genotype). Sixty-six subjects entered a cross-over, randomized trial involving 12 weeks on each drug. Efficacy was assessed after 6 and 12 weeks on each treatment. Simvastatin lowered total cholesterol 24%, triglycerides 12%, LDL cholesterol 33%, raised HDL cholesterol 13% and substantially reduced the cholesterol:triglyceride ratio in VLDL and IDL. Gemfibrozil lowered total cholesterol 5%, triglycerides 44%, raised HDL 26% and reduced VLDL and IDL lipids more than simvastatin did. LDL size increased with both treatments and HDL size increased with simvastatin. Responsiveness (25% fall in cholesterol or 40% fall in triglycerides) was shown by 31/61 subjects when taking simvastatin (cholesterol-lowering) and by 44/60 taking gemfibrozil (triglyceride-lowering). Responsiveness was greatest in those with apo E2 genotype with both drugs (P < 0.05). Unexpectedly, responders to simvastatin tended to have lower baseline total cholesterol but higher triglyceride levels than those whose cholesterol or triglyceride was lowered by gemfibrozil. Nevertheless, more hypercholesterolemic subjects responded to simvastatin and more hypertriglyceridemic subjects to gemfibrozil. Lp(a) (P = 0.04) and plasma insulin concentrations (P = 0.03) were negative predictors of percentage triglyceride-lowering with gemfibrozil. The difference between the two drugs in triglyceride-lowering lessened with rising insulin and falling HDL cholesterol. Thus, the responsiveness to the two major classes of lipid lowering drugs can be partly predicted from baseline lipids and related metabolic parameters.

[Clinical manifestations of the insulin resistance syndrome. The hormonal-metabolic syndrome X, the 5H syndrome and their etiopathogenesis]

The author summarizes mechanisms by which insulin resistance and compensatory hyperinsulinism are manifested in the clinical picture. He divides the mechanisms into prereceptor, receptor and postreceptor mechanisms. The latter dominate in the population quantitatively and thus also by their impact because they create the so-called 5H syndrome (association of hyperinsulinism with hyperglycaemia (NIDDM), hyperlipoproteinaemia, hypertension, hirsutism and the polycystic ovary syndrome) or the so-called hormonal metabolic syndrome X, lethal tetrad, metabolic syndrome, syndrome of insulin resistance). The term syndrome X does not appear suitable as it is frequently mistaken for coronary X syndrome which probably is also conditioned by hyperinsulinism, for the hormonal metabolic X syndrome and probably also fot the "fragile X syndrome" in genetics. The 5H syndrome is caused by a postreceptor disorder of insulin efficiency for which so far the molecular basis and dominating organ site have not yet been defined adequately. Hyperinsulinism is conceived as an insulin resistance compensating phenomenon. In its development participates, however, in addition to compensatory hypersecretion also impaired insulin utilization (liver, muscles) and an impaired primary secretory response caused probably by a disorder of blood sugar control (glucokinase, GLUT 2). This is suggested by the frequently inadequate response of the blood sugar level, IRI and C-peptide during the oral glucose tolerance test (OGGT). A hyperinsulinaemic response may be encountered when the blood sugar curve is normal, flat, in impaired glucose tolerance and in diabetes. Thus OGGT alone is not suited for the early detection of the 5H syndrome unless concurrently the IRI and C-peptide response is recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

[Patient education in the metabolic syndrome]

In the treatment of the metabolic syndrome which comprises the most serious risk factors of atherosclerosis education is a basic prerequisite of treatment and prevention of complications. In the submitted review the authors analyze basic procedures of education from the general aspect as well as in individual disorders and diseases which characterize the metabolic syndrome (dyslipoproteinaemia, obesity, diabetes mellitus and impaired glucose tolerance, hypertension). They emphasize that a comprehensive change of the patient's life style and the life style of his whole family is necessary. This cannot be achieved within a short time and therefore motivation of the patient as well as of the health professionals engaged in the educational work is essential.

[The dilemma of syndrome X]

The term X syndrome involves several dilemmas. The terminological dilemma is that this term is used to describe microvascular angina pectoris, as well as Reaven's metabolic-hormonal syndrome and our 5H syndrome [association of hyperinsulinism with arterial hypertension, hyperlipoproteinaemia, hyperglycaemia (NIDDM) and hirsutism]. It is probable that the coronary X syndrome is frequently conditioned by the hormonal-metabolic X syndrome. The pathogenetic dilemma is that it is not clear why in microvascular angina pectoris the coronary circulation does not possess an adequate reserve for vasodilatation during exercise or in response to some pharmacological stimuli. This could condition hyperinsulinism in hypertonic subjects with NIDDM with an early disorder of paracrine endothelial relaxation mechanisms (EDRF-NO), with a predominance of vasoconstrictor mechanisms (endothelin-1). In Reaven's syndrome X it is not clear whether insulin resistance of the postreceptor type is a primary inborn phenomenon which is compensated by insulin hypersecretion or whether it is a secondary phenomenon, which develops ex post and by which the target tissues defend themselves against an excessive effect of insulin (e.g. down regulation receptors) in primary disorders of its secretion.

[Hyperinsulinism as a major etiopathogenic link with arterial hypertension, hyperlipoproteinemia and hirsutism. II]

The authors analyze mechanism by which hyperinsulinism causes NIDDM, hypertension, hyperlipoproteinaemia and hirsutism (5H syndrome). They demonstrate on a group of their 100 patients with NIDDM and arterial hypertension that, as compared with matched pairs without arterial hypertension, they have significantly higher levels of C-peptide and less favourable parameters of dyslipoproteinaemia. Hirsutism occurs in 10-15% of the adult female population, but in 18.4% women with NIDDM. However, in a group of 48 hirsutic women with NIDDM they did not find, as compared with matched pairs (i.e. women with NIDDM of analogous age, BMI and BP) significantly higher C-peptide and lipid levels. According to the authors congenital insulin resistance modified by numerous endogenous and exogenous factors is eventually manifested in the phenotype, in particular via hyperinsulinism as NIDDM, hypertension, associated with dyslipoproteinaemia and obesity which then, as the main risk factors, condition a high cardiovascular morbidity and mortality. Although hirsutism and the polycystic ovary syndrome are associated with hyperinsulinism, their interrelation is probably less close and thus has not such a negative impact on national health.

[Clinical manifestations of insulin resistance. The hormonal-metabolic syndrome X (5H), its prevalence and impact on cardiovascular morbidity and mortality. I]

Insulin resistance (prereceptor, receptor, postreceptor) is a complex phenomenon. It penetrates into the clinical picture via hyperinsulinism as impaired glucose tolerance, or NIDDM, as hyperlipoproteinaemia, arterial hypertension and hirsutism in women (syndrome 5H) associated with the polycystic ovary syndrome or the HAIR-AN syndrome. Based on a group of their 480 patients with NIDDM, 108 women with hirsutism, 320 patients with myocardial infarction and the results of the national cardiovascular programme the authors estimate the prevalence of the 5H syndrome as follows: in the general population 5-10%, in patients with arterial hypertension 15-30%, in NDDM 65-90%, in hirsutic women 10-20% and in patients with myocardial infarction 30-50%. These figures could be, however, substantially higher if as the criterion the IRI response was taken or that of C-peptide in OGTT or the results of the hyperinsulinaemic euglycaemic clamp. The clinical 5H syndrome is a phenomenon of latent insulin resistance perceived late by doctors and patients.

Inherited disorders of lipid transport

The number of well-described discrete disorders of lipid transport is increasing, and the classification of the disorders also is changing, from one based on altered concentrations of classes of lipoproteins, to one based on improved understanding of the genetics of the disorders and of lipoprotein biochemistry and physiology. Many disorders are now traceable to structural defects in or the absence of key proteins such as apolipoproteins, enzymes, lipid transfer proteins, and cellular receptors.

Apoprotein b-poor very low density lipoprotein in diabetic patients without hyperlipoproteinemia

In order to see if there is a latent metabolic disorder of plasma very low density lipoprotein (VLDL) in uncontrolled diabetic patients without hyperlipoproteinemia, 28 diabetic patients and 13 matched normal subjects were analyzed for the compositions of fasting plasma VLDL. Although the lipid profiles and total apoproteins were similar among the normals, normolipoproteinemic well-controlled diabetics and normolipoproteinemic poorly-controlled diabetics, VLDL apoprotein B content tended to be decreased in poorly-controlled diabetics. Consequently, triglyceride/apoprotein B ratio was found to be increased significantly (p less than 0.02) to 12.5 +/- 1.3 (mean +/- S.E.) in the normolipoproteinemic poorly-controlled diabetics as compared with that in the normals (8.1 +/- 0.7). Since plasma VLDL is known to become relatively enriched with apoprotein B as the VLDL delipidation proceeds, the apoprotein B-poor VLDL in the normolipoproteinemic poorly-controlled diabetics seems to reflect a latent delayed turnover of circulating VLDL and this might be the disorder characteristic to diabetes mellitus.