Elżbieta Kimak

Concentration of Lp(a) and other Apolipoproteins in Predialysis, Hemodialysis, Chronic Ambulatory Peritoneal Dialysis and Post-Transplant Patients

Abstract Serum levels of lipids, lipoprotein(a) Lp(a) and other apolipoproteins were determined in 47 predialysis patients, 40 hemodialysis (HD) patients, 39 chronic ambulatory peritoneal dialysis (CAPD) patients, 11 patients after kidney transplantation and 47 healthy subjects as reference group. The predialysis, HD, and CAPD patients had disturbances in the concentration of serum triglyceride (TG), high density lipoprotein (HDL)-cholesterol, apolipoprotein AI (apoAI), total apoCIII, apoCIII present in the particles without apoB (apoCIII non B), and Lp(a) and HDL-cholesterol, low density lipoprotein (LDL)-cholesterol/HDL-cholesterol, HDL-cholesterol/apoAI, apoAI/apoB, and apoAI/apoCIII ratios. Predialysis patients had significantly lower concentrations of HDL-cholesterol and total apoE levels than CAPD patients and total apoE level than HD patients. Moreover, both HD and CAPD patients had significantly increased levels of apoB containing apoE (apoB:E) and apoB containing apoCIII (apoB:CIII). The concentrations of serum TG, total cholesterol, LDL-cholesterol, apoB, Lp(a) in CAPD patients were statistically higher than in HD patients. The patients after transplantation demonstrated normalization of lipid and lipoprotein parameters and lipoprotein ratios except serum levels of TG, total apoCIII, apoCIII non B and the apoAI/apoCIII ratio. We concluded that abnormal lipid and lipoprotein concentrations in patients with uremia may be the cause of their high risk of atherosclerosis, but post-transplant patients exhibited improved levels of serum lipids, Lp(a) and other lipoprotein parameters and lipoprotein composition, which could be an index of decreased atherogenic status.

ApoA- and apoB-containing lipoproteins and Lp(a) concentration in non-dialyzed patients with chronic renal failure.

Background: End-Stage renal disease is associated with accelerated atherosclerosis and a high incidence of cardiovascular disease. Methods: The serum levels of lipids and apolipoproteins and Lp(a) were determined in 51 patients with chronic renal failure (CRF) with various advancement, without interference of factors which might disturb Lp(a) metabolism and with proteinuria less than 0.5 g/24 h. The patients studied were divided into two groups: patients with moderate renal failure (CRF-M) and creatinine levels of 2–6 mg/dL n = 27; and predialysis patients with end stage renal disease (ESRD) and creatinine levels higher than 8.5 mg/dL n = 24. Results: In both studied groups serum concentrations of triglycerides (TG), total apoCIII, apoCIIInonB, apoB:CIII were statistically increased, (except total cholestrol (TC) and LDL-cholestrol (LDL-C), apoB, total apoE, apoEnonB, apoB:E), while the levels of HDL-cholestrol (HDL-C) and apoAI significantly decreased. Lipid and lipoprotein ratios as risk factors of atherosclerosis were similar in both groups. The TC/HDL-C ratio increased, while that of HDL-C/apoAI and apoAI/apoCIII decreased. Serum Lp(a) concentrations were significantly increased in both studied groups. The medians and ranges of Lp(a) concentration were similar in both groups. Serum Lp(a) levels correlated with total cholesterol (r = 0.295; p < 0.05), LDL-C (r = 0.312; p < 0.05) and apoB (r = 0.215; p < 0.05). In addition, no correlation was found between Lp(a) levels and albumin concentrations (r = 0.126; p = 0.421). Conclusion: Our results may indicate that the reduced levels of apoA-containing lipoproteins and increased TG-rich apoB-containing lipoproteins and Lp(a) indicated a clear atherogenic pattern in early renal disease. Increased Lp(a) concentration may result in nonspecific synthesis or catabolism disturbances. Measurement and monitoring of lipoprotein family profiles offers a new means for selecting appropriate therapies targeted for normalizing dyslipidemia in non-dialyzed patients.

Disturbed lipids, lipoproteins and triglyceride-rich lipoproteins as well as fasting and nonfasting non-high-density lipoprotein cholesterol in post-renal transplant patients.

Serum levels of lipids and lipoproteins were determined in 98 post-renal transplant fasting patients, and lipids and non-high density lipoprotein-cholesterol (non-HDL-C) and lipid ratios in the same post-renal transplant non-fasting patients were compared. The reference group was 87 healthy subjects. All patients were divided into two groups: patients with dyslipidemia (n = 69) and patients with normolipidemic (n = 29). The post-renal transplant patients (TX) with dyslipidemia had a significantly increased concentration of triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), non-HDL-C, apoB, and TRL and lipid ratios, and decreased HDL-C level and lipoprotein ratios. The lipids, lipoproteins, and lipoprotein ratios were significantly beneficial in TX patients with normolipidemic than in those with dyslipidemia. However, TRL concentration and lipid ratios were significantly increased and apoAI/apoCIII significantly decreased as compared to the reference group. The TX patients with dyslipidemia showed a significant correlation between TG and apoB:CIII (r = 0.562, p < 0.001) and apoCIII (r = 0.380, p < 0.004), but those with normolipidemic showed a significant correlation only between TG and apoCIII (r = 0.564, p < 0.008). Regression and Bland-Altman analyses showed excellent correlation between fasting and nonfasting non-HDL-C levels (r = 0.987, R2 + 0.987) in TX patients both with dyslipidemia and normolipidemic. We think the finding that nonfasting labs that are reliable for non-HDL-C as well as total cholesterol is important, as fasting labs are not always available. Disturbances of lipids, lipoproteins, and TRLs depend not only on the kind of treatment, but due to multiple factors can accelerate cardiovascular complications in post-renal transplant patients with dyslipidemia and also with normolipidemic. Further studies concerning this problem should be completed.

Relationships between serum lipid, lipoprotein, triglyceride-rich lipoprotein, and high-density lipoprotein particle concentrations in post-renal transplant patients

ObjectiveDisturbances in lipid and lipoprotein profiles in patients after kidney transplantation (Tx) are still not understood.MethodsSerum levels of lipids, lipoprotein, triglyceride-rich lipoproteins (TRLs), and high-density lipoprotein (HDL) particles were determined, lipid and lipoprotein ratios were calculated, and their relationships in Tx patients with hypertriglyceridemia (HTG) and lower apolipoprotein AI (apoAI) concentration were examined. Serum lipid and lipoprotein levels were measured in 109 Tx patients and 89 healthy subjects. HDL particle levels were determined by enzyme-linked immunosorbent assay (ELISA).ResultsTx patients had disturbed concentration, composition, and metabolism of TRLs and HDL particles. Multivariance analysis showed significant and positive correlation between HDL cholesterol/apoAI (HDL-C/apoAI) and HDL-C/HDL ratios, which indicates that both ratios could sensitively reflect changes in the HDL subclasses and their distribution into smaller size particles. In Tx patients, the decreased HDL-C/apoAI ratio indicates that, along with the decreased apoAI concentration, the HDL-C level is decreased. However, a low HDL-C/HDL ratio indicates that HDL particles in Tx patients transport lesser content of HDL-C but more triglyceride (TG) (high TG/HDL ratio), and thus are hypercatabolized and removed; therefore, concentration of HDL particles in serum was decreased.ConclusionThe decrease of HDL-C/apoAI ratio seems to be a good marker of HDL subclass distribution into smaller size particles.

Association between moderately oxidized low-density lipoprotein and high-density lipoprotein particle subclass distribution in hemodialyzed and post-renal transplant patients

Disturbances in the metabolism of lipoprotein profiles and oxidative stress in hemodialyzed (HD) and post-renal transplant (Tx) patients are proatherogenic, but elevated concentrations of plasma high-density lipoprotein (HDL) reduce the risk of cardiovascular disease. We investigated the concentrations of lipid, lipoprotein, HDL particle, oxidized low-density lipoprotein (ox-LDL) and anti-ox-LDL, and paraoxonase-1 (PON-1) activity in HD (n=33) and Tx (n=71) patients who were non-smokers without active inflammatory disease, liver disease, diabetes, or malignancy. HD patients had moderate hypertriglyceridemia, normocholesterolemia, low HDL-C, apolipoprotein A-I (apoA-I) and HDL particle concentrations as well as PON-1 activity, and increased ox-LDL and anti-ox-LDL levels. Tx patients had hypertriglyceridemia, hypercholesterolemia, moderately decreased HDL-C and HDL particle concentrations and PON-1 activity, and moderately increased ox-LDL and anti-ox-LDL levels as compared to the reference, but ox-LDL and anti-ox-LDL levels and PON-1 activity were more disturbed in HD patients. However, in both patient groups, lipid and lipoprotein ratios (total cholesterol (TC)/HDL-C, LDL-C/HDL-C, triglyceride (TG)/HDL-C, HDL-C/non-HDL-C, apoA-I/apoB, HDL-C/apoA-I, TG/HDL) were atherogenic. The Spearman’s rank coefficient test showed that the concentration of ox-LDL correlated positively with HDL particle level (R=0.363, P=0.004), and negatively with TC (R=−0.306, P=0.012), LDL-C (R=−0.283, P=0.020), and non-HDL-C (R=−0.263, P=0.030) levels in Tx patients. Multiple stepwise forward regression analysis in Tx patients demonstrated that ox-LDL concentration, as an independent variable, was associated significantly positively with HDL particle level. The results indicated that ox-LDL and decreased PON-1 activity in Tx patients may give rise to more mildly-oxidized HDLs, which are less stable, easily undergo metabolic remodeling, generate a greater number of smaller pre-β-HDL particles, and thus accelerate reverse cholesterol transport, which may be beneficial for Tx patients. Further studies are necessary to confirm this.

Disturbed lipoprotein composition in non-dialyzed, hemodialysis, continuous ambulatory peritoneal dialysis and post-transplant patients with chronic renal failure.

Abstract Studies were carried out in 183 non-dialyzed, 123 hemodialysis, 81 continuous ambulatory peritoneal dialysis and 35 post-transplant patients and in 103 healthy subjects as a reference group. Lipids and apolipoprotein (apo)AI and apoB were determined using Roche kits. An anti-apoB antibody was used to separate apoB-containing apoCIII and apoE-triglyceride-rich lipoprotein (TRL) in the non-high-density lipoprotein (non-HDL) fraction from apoCIIInonB and apoEnonB in the HDL fraction in four groups of patients with chronic renal failure (CRF) and healthy subjects. Multivariate linear regression analysis was used to investigate the relationship between triglyceride (TG) or HDL-cholesterol (HDL-C) concentrations and lipoproteins. Dyslipidemia varied according to the degree of renal insufficiency, the type of dialysis and therapy regime in CRF patients. Lipoprotein disturbances were manifested by increased TG, non-HDL-C and TRL concentrations, and decreased HDL-C and apoAI concentrations, whereas post-renal transplant patients showed normalization of lipid and lipoprotein profiles, except for TG levels and total apoCIII and apoCIIInonB. The present study indicates that CRF patients have disturbed lipoprotein composition, and that hypertriglyceridemia and low HDL-C concentrations in these patients are multifactorial, being secondary to disturbed lipoproteins. The method using anti-apoB antibodies to separate apoB-containing lipoproteins in the non-HDL fraction from non-apoB-containing lipoproteins in HDL can be used in the diagnosis and treatment of patients with progression of renal failure or atherosclerosis. The variability of TG and HDL-C concentrations depends on the variability of TRL and cholesterol-rich lipoprotein concentrations, but the decreases in TG and increases in HDL-C concentrations are caused by apoAI concentration variability. These relationships, however, need to be confirmed in further studies.

Plasma lipoproteins in patients with chronic renal failure (CRF)

The clinical picture in chronic renal failure (CRF) shows great variability depending on age, sex, aetiology of disease, grades of renal injury and type of treatment.Significant increases of triglycerides (TG), low-density lipoprotein cholesterol (LDL-chol) and apo B concentrations, significant decreases of high-density lipoprotein cholesterol (HDL-chol) levels and apo A and apo AI concentrations, and no significant changes in total cholesterol (TC) have been shown in CRF patients. Significant increases of TC/HDL-chol, LDL-chol/HDL-chol, apo B/apo AI and apo B/LDL-chol ratios were also demonstrated. That indicates a high risk of atherosclerosis even when total cholesterol levels are in the normal range. There were highly significant and positive correlations between TC/HDL-chol and LDL-chol/HDL-chol ratios, apo B and LDL-chol concentrations as well as between the apo B/apo AI and LDL-chol/HDL-chol ratios.

Lipid and lipoprotein ratios as risk factors of atherosclerosis in patients with chronic renal insufficiency (CRI).

The serum levels of lipids, apolipoproteins and lipoprotein ratios in 19 healthy persons and 20 patients with uraemia not dialyzed were determined. Based on creatinine level the patients were divided into two groups: L (serum creatinine 2–5 mg/dl) and H (serum creatinine 5–10 mg/dl).Dyslipoproteinaemia in uraemic patients is already manifested in the early stages of the disease through its abnormal apolipoproteins rather than lipid profile and it suggests a high risk of atherosclerosis.

Lipoprotein profiles at different stages of chronic renal insufficiency.

Background Lipoprotein abnormalities characteristic of renal dyslipoproteinemia are significantly associated with different stages of chronic renal insufficiency. The renal dyslipoproteinemia may contribute not only to accelerated development of atherosclerosis but also to progression of human chronic renal insufficiency.Methods The purpose of the studies was to estimate the lipid and lipoprotein profiles in 52 not dialysed patients with various renal insufficiency advancement. Basing on creatinine level the patients were divided into 3 groups. CR1-A—serum creatinine 2–5 mg/dL (n = 16), CR1-B—serum creatinine 5–10 mg/dL (n = 19), CR1-C—serum creatinine > 10 mg/dL (n = 17).Results In CR1-A and CR1-B dyslipoproteinemia was found at different stages of renal insufficiency which was manifested by the significant increase of TG, TC, LDL-C, apo B levels and TC/HDL-C, LDL-C/HDL-C ratios and significant decrease of HDL-C level and apo AI/apoB, HDL-C/apoAI ratios in comparison with controls. We also observed decreased TG, TC, LDL-C, apo AI, apo B levels and TC/HDL-C, LDL-C/HDL-C ratios and unchanged HDL-C level and apo AI/apoB, HDL-C/apoAI ratios in cm-c in comparison to CR1-A. The decrease of the lipoprotein parameters in CR1-C might result from malnutrition (statistically decreased albumin level) and metabolism disturbances connected with the renal insufficiency advancement. Negative correlation between IG, HDL-C levels (r = −0.43, p < 0.001) and TG, IIDL-C/apoAI (r = −0.56; p < 0.001) were found, which confirmed the abnormal composition of HDL molecules and indicated a high risk of atherosclerosis. Conclusion Our results may indicate that of atherosclerosis in CR1 patients is connected with dyslipoproteinemia and disturbances in HDL molecular composition and with different stages of chronic renal insufficiency.

Association Between Lipids, Lipoproteins Composition of HDL Particles and Triglyceride-Rich Lipoproteins, and LCAT and CETP Activity in Post-renal Transplant Patients

High-density lipoprotein (HDL) remodeling within the plasma compartment and the association between lecithin-cholesterol acyltransferase (LCAT) and cholesterol ester transfer protein (CETP) activity, and lipid, lipoprotein concentrations and composition were investigated. The aim was to examine the high sensitivity of C-reactive protein (hsCRP), lipid, apolipoprotein B (apoB), apoAI, total apoAII, apoAIInonB, apoB-containing apoAII (apoB:AII), total apoCIII, apoCIIInonB, apoB-containing apoCIII (apoB:CIII) concentration and LCAT and CETP activity to gain an insight into the association between them and LCAT and CETP, 57 post-renal transplant (Tx) patients with and without statin therapy and in 15 healthy subjects. Tx patients had moderate hypertriglyceridemia, hypercholesterolemia, and dyslipoproteinemia, disturbed triglyceride-rich lipoproteins (TRLs) and HDL composition, decreased LCAT, and slightly increased hsCRP but no CETP activity. Spearman’s correlation test showed the association between lipids and lipoproteins and LCAT or CETP, and multiple ridge stepwise forward regression showed that immunosuppressive therapy in Tx patients can disturb HDL and TRLs composition. The results suggest that inhibition or activation of LCAT is due, in part, to HDL-associated lipoprotein. Lipoprotein composition of apoAI, apoAIInonB, and apoCIIInonB in HDL particle and apoB:AII TRLs can contribute to decrease LCAT mass in Tx patients. Tx patients without statin and with lower triglycerides but higher HDL cholesterol concentration and disturbed lipoprotein composition of ApoAI and apoAII in HDL particle can decrease LCAT, increase LDL cholesterol, aggravate renal graft, and accelerate atherosclerosis and chronic heart diseases.