Treatment of Homozygous Familial Hypercholesterolemia with Low Density Lipoprotein Apheresis: A 4 Year Follow-Up Study

Abstract: Hypercholesterolemia and elevated lipoprotein (a) (Lp[a]) levels are considered to be risk factors for the development and progression of premature atherosclerosis. The purpose of our report is to describe the effects of low density lipoprotein (LDL) apheresis (Liposorber system, Kanegafuchi Chemical Industrial Company LTD, Osaka, Japan) on serum lipoprotein concentrations and the clinical status in 2 male patients with homozygous familial hypercholesterolemia. Compared with pretreatment values, the posttreatment concentrations of total cholesterol, LDL cholesterol, and Lp(a) were significantly reduced by 50–60% (p < 0.0001). The concentration of high density lipoprotein (HDL) cholesterol was slightly affected. After one treatment session, LDL cholesterol and Lp(a) were decreased on average by 65% and then increased to reach about 70–75% of the pretreatment values before the next session. Prior to the treatment with LDL apheresis, each patient had suffered one myocardial infarction and had had 2 coronary angiographies. After treatment with LDL apheresis, neither cardiac complaints nor myocardial infarction were observed. The xanthomas were much decreased during the treatment or disappeared. We conclude that LDL apheresis can be continued safely and without major technical problems for several years. Apheresis effectively lowers the serum levels of total and LDL cholesterol. Furthermore, it reduces Lp(a), which is not influenced by lipid-lowering drugs. The reduction of LDL cholesterol and Lp(a) may delay the progression of the atherosclerotic process, thereby helping to reduce the risk of new episodes of coronary heart disease and thus extending the life expectancy in these patients.     

LDL Apheresis: A Novel Technique (LIPOCOLLECT 200)

Therapeutic means to lower Lp(a) are limited. The most effective method to reduce plasma Lp(a) concentration significantly is therapeutic apheresis, namely, low‐density lipoprotein (LDL) lipoprotein(a) (Lp(a)) apheresis. A novel technique based on reusable LDL adsorber called Lipocollect 200 (Medicollect, Rimbach, Germany) allows the removal of both LDL and Lp(a) from plasma. Two male patients with hyperLp(a)lipoproteinemia and angiographically established progressive coronary heart disease, without rough elevation of LDL‐cholesterol, who did not respond to diet and medication were submitted to 50 LDL Lp(a) aphereses with Lipocollect 200 LDL Lp(a)‐adsorber at weekly and biweekly intervals. Total cholesterol and LDL cholesterol plasma levels fell significantly by 48.3% (±6.7) to 61.6% (±12.7) (first patient), and 42.5% (±6.3) to 60.6% (±14.3) (second patient), respectively (all differences: P ≤ 0.001). High‐density lipoprotein (HDL)‐cholesterol concentration in plasma did not show statistically significant change. Plasma triglycerides were also significantly reduced by 43.6% (±24.4) (first patient) and 42.3% (±13) (second patient) (both differences: P ≤ 0.001). Plasma Lp(a) showed a statistically significant percent reduction in plasma as expected: 64.7 ± 9.5 (first patient), and 59.1 ± 6.7 (second patient) (both differences: P ≤ 0.001). Plasma fibrinogen concentration was decreased by 35.9% (±18.7) (P ≤ 0.05) (first patient) and 41.8% (±11.5) (second patient) (P ≤ 0.005). Considering the reduction rate between the first and the last procedures, we have compared the mean percent reduction of the first five treatments (from session #1 to #5) with the last five treatments (from session #21 to #25). We have observed an increasing reduction of all activity parameters on both patients apart from HDL‐cholesterol (first patient) and triglyceride (second patient) that showed a decreasing reduction rate. Both patients followed the prescribed schedule and completed the study. Clinically, all sessions were well tolerated and undesired reactions were not reported. The Lipocollect 200 adsorber proved to have a good biocompatibility. In this study, the adsorber reusability for several sessions was confirmed.     

Low–Density Lipoprotein Apheresis in the Treatment of Two Patients with Coronary Heart Disease and Extremely Elevated Lipoprotein (a) Levels

Abstract: Hyperlipidemia and elevated lipoprotein (a) (Lp[a]) levels have been linked to the development and progression of premature atherosclerosis. Our study concerned 2 white male patients (aged 36 and 42 years) with heterozygous familial hypercholesterolemia and extremely elevated Lp(a) concentrations that were resistant to diet regimens and lipid–lowering drugs. The patients were treated with low–density lipoprotein (LDL) apheresis for 59 months (Liposorber system, Kaneka, Japan) and 19 months (immunoadsorption system, special Lp(a) columns; Lipopak; Pocard, Russia), respectively. The concentration of Lp(a) decreased on average by 50%, total cholesterol by 27%, LDL cholesterol by 41%, triglycerides by 43%, and fibrinogen by 16%. High–density lipoprotein (HDL) cholesterol increased by approximately 4%. Before treatment with LDL apheresis, each patient had suffered 3 myocardial infarctions, and had had 4 and 6 coronary angiographies with 2 and 4 percutaneous transluminal angioplasties (PTCAs), respectively. Since treatment with LDL apheresis, no myocardial infarctions or cardiac complaints were observed. In the course of treatment, both patients reported an increased performance. Available data suggest that LDL apheresis may be effective in the treatment of patients, the only risk factor for premature atherosclerosis being extremely elevated Lp(a) concentrations.     

State of the Art of Lipid Apheresis

Abstract: Currently, 5 different lipid apheresis procedures are available for routine clinical treatment of hy–percholesterolemic patients. Unselective plasma exchange is a technically simple extracorporeal circuit, but albumin substitution fluid must be used and there is no high–density lipoprotein (HDL) recovery. Semiselective double filtration with improved size selectivity because of a small–pore secondary filter combines good elimination of low–density lipoprotein (LDL), lipoprotein (a) (Lp[a]), and fibrinogen with adequate HDL recovery; modifications such as thermofiltration, predilution/backflush, or pulsatile flow have been proposed for the improvement of this system. Three highly selective procedures are basedon immunologic or electrostatic interactions: immunoad–sorption using anti–low–density lipoprotein (LDL) antibodies, chemoadsorption onto dextran sulfate, and hep–arin–induced LDL precipitation (HELP) apheresis. The features of each system are discussed critically. Lastly, two new developments, Lp(a) immunoadsorption and LDL hemoperfusion using a polyacrylate LDL adsorber compatible with whole blood, are described     

Treatment of Severe Hyperlipidemia: Six Years' Experience with Low–Density Lipoprotein Apheresis

Abstract: In total, 30 patients suffering from familial hypercholesterolemia, resistant to diet and lipid–lowering drugs, were treated for up to 6 years (3.6 ± 1.6; range, 0.2–6.8 years) with low–density lipoprotein (LDL) apheresis. Three different systems were used; the dextran sulfate adsorption system (Kaneka) for 27 of 30 patients, the immunoadsorption system from Baxter for 2 of 30 patients, and the immunoadsorption system with special li–poprotein(a) (Lp[a]) columns from Lipopak for one patient. Prior to the LDL apheresis, 23 of 30 patients suffered from coronary heart disease. Twenty of 23 patients suffered intermittently from symptoms of angina, excertional dyspnea, and claudication. With LDL apheresis, reductions of 47% for total cholesterol, 49% for LDL, 26% for Lp(a), and 40% for triglycerides were reached. Severe side effects such as shock or allergic reactions were very rare (0.55%). In the course of treatment with LDL apheresis, an improvement in general well–being and increased performance were experienced in 27 of 30 patients. A reduction of nitrate medication between 60 and 100% was observed in 17 of 23 patients. The present data clearly demonstrate that treatment with LDL apheresis in patients suffering from severe familial hyperlipidemia, resistant to maximum conservative therapy, is very effective and safe even over long periods of time.     

Does Regular Lipid Apheresis in Patients With Isolated Elevated Lipoprotein(a) Levels Reduce the Incidence of Cardiovascular Events?

Elevated lipoprotein(a) (Lp(a)) is known as an independent risk factor for atherosclerosis and cardiovascular events. Regular lipid apheresis decreases elevated Lp(a) concentrations. However, there is a lack of reliable data regarding the effect of lipid apheresis on cardiovascular endpoints. To assess the effects of apheresis, we compared the occurrence of cardiovascular events in 37 patients treated regularly with lipid apheresis at the time periods of preinitiation of apheresis and during apheresis treatment. A retrospective analysis of 37 patients (35 men and two women; aged 58 years ± 11 [mean ± standard deviation]; body mass index 26 kg/m² ± 3; low‐density lipoprotein (LDL)‐cholesterol before apheresis 84 mg/dL ± 21; Lp(a) before apheresis 112 mg/dL ± 34) treated regularly with lipid apheresis was performed. Patients' medical records were screened for cardiovascular events at the preapheresis and during apheresis periods. Apheresis led to a significant reduction of lipid levels (LDL cholesterol ?60%; Lp(a) –68%) measured after apheresis. The event‐free survival rate after 1 year in the preapheresis period was 38% (22–54%, 95% confidence interval [CI]) vs. 75% (61–89%, 95% CI) in the during‐apheresis period with a statistically significant difference (P < 0.0001). Apheresis seems to lower the progression of atherosclerosis leading to a reduced number of cardiovascular events in hyperlipoproteinemia(a). Because prospective and controlled trials are lacking, the therapeutic effectiveness of lipid apheresis can only be estimated.     

Low-density lipoprotein apheresis: clinical results with different methods

In 40 patients (22 women, 18 men) suffering from familial hypercholesterolemia resistant to diet and lipid lowering drugs, low-density lipoprotein (LDL) apheresis was performed over 84.9 +/- 43.2 months. Four different systems (Liposorber, 28 of 40, Kaneka, Osaka, Japan; Therasorb, 6 of 40, Baxter, Munich, Germany; Lipopak, 2 of 40, Pocard, Moscow, Russia; and Dali, 4 of 40, Fresenius, St. Wendel, Germany) were used. With all methods, average reductions of 50.6% for total cholesterol, 52.2% for LDL, 64.3% for lipoprotein (a) (Lp[a]), and 43.1% for triglycerides, and an average increase of 10.3% for high-density lipoprotein (HDL) were reached. Severe side effects such as shock or allergic reactions were very rare (0.5%) in all methods. In the course of treatment, an improvement in general well being and increased performance were experienced by 39 of 40 patients. Assessing the different apheresis systems used, at the end of the trial, there were no significant differences with respect to the clinical outcome experienced with the patients' total cholesterol, LDL, HDL, and triglyceride concentrations. However, to reduce high Lp(a) levels, the immunoadsorption method with special Lp(a) columns (Lipopak) seems to be most effective: -59% versus -25% (Kaneka) - (Baxter), and -29% (Dali). The present data demonstrate that treatment with LDL apheresis of patients suffering from familial hypercholesterolemia resistant to maximum conservative therapy is very effective and safe even in long-term application.     

Efficacy and safety of a new whole-blood low-density lipoprotein apheresis system (Liposorber D) in severe hypercholesterolemia

Low-density lipoprotein (LDL) apheresis is an extracorporeal modality to lower LDL cholesterol. While most of the devices eliminate LDL particles from plasma, a recently introduced whole-blood perfusion column (DALI) adsorbs lipoproteins directly from whole blood. We investigated the efficacy and safety of a new whole-blood LDL apheresis system (Liposorber D) in 10 patients with severe hypercholesterolemia in a multicenter trial. In 93 LDL aphereses, the mean reduction in LDL cholesterol and lipoprotein(a) was 62.2 +/- 11.5% and 55.6 +/- 16.9%, respectively (P < 0.01). If hemodilution during apheresis was considered, the reductions were 58.0 +/- 10.9 and 55.3 +/- 10.9%, respectively (P < 0.01), while high-density lipoprotein (HDL) cholesterol did not change significantly. Three mild episodes of hypocalcemia and two mild episodes of arterial hypotension were observed; however, LDL apheresis could be continued in each case. In conclusion, the new whole-blood LDL apheresis with Liposorber D is a safe, simple, and useful modality to reduce LDL cholesterol and lipoprotein(a) in cardiovascular high-risk patients.     

Low–Density Lipoprotein Removal Methods by Membranes and Future Perspectives

Abstract: Since the application by Thompson et al. in 1975 of plasma exchange for the treatment of 2 patients with familial hyperlipidemia, plasma purification techniques for selective low–density lipoprotein (LDL) removal (i.e., LDL apheresis) have been developed and adopted for the management of this disease. Thermofil–tration is one of the LDL apheresis systems that utilizes membrane techniques developed by Nose and Malchesky's group in 1985. This article reviews its rationale, in vitro studies, animal studies, and clinical investigation. Thermofiltration effectively and selectively removes LDL cholesterol while retaining in the plasma physiologically important macromolecules such as albumin and high–density lipoprotein (HDL) cholesterol. Based on the global view of the treatment of atherosclerosis by LDL apheresis, membrane techniques are as effective, safe, and simpler to apply than other methods. Additionally, these methods are effective for the removal of lipoprotein (a) and fibrinogen; thus, they can address the needs in these application areas.     

LDL Hemoperfusion-A New Procedure for LDL Apheresis: First Clinical Application of an LDL Adsorber Compatible with Human Whole Blood

Abstract: To date, lipid apheresis procedures can remove low-density lipoprotein (LDL) cholesterol (LDL-C) only from plasma. Thus, initially plasma has to be separated from the blood cells, which increases the costs and complexity of the extracorporeal circuit. This paper describes the first clinical application of a new LDL adsorber that eliminates LDL directly from whole blood. The goal of this pilot study was to test the efficacy, safety, and feasibility of direct lipoprotein adsorption in patients. In a 2 center Phase II clinical trial, 12 hypercholesterolemic patients suffering from overt coronary or peripheral artery disease were treated once with LDL hemoperfusion. The new LDL adsorber (DALI, Fresenius, St. Wendel, Germany) contained 480 ml of polyacrylate coated polyacrylamide gel. The anticoagulation consisted of an initial heparin bolus followed by an acid citrate dextrose (ACD)-A infusion during the treatment. The processing of nearly 1 patient blood volume resulted in a reduction of LDL-C by 45 ± 8% and triglycerides by 23 ± 20%. HDL-C, fibrinogen, and cell counts were not significantly influenced. In a subgroup of 5 patients who exhibited elevated lipoprotein (a) (Lp[a]) levels, Lp(a) reduction was 43 ± 15% (all results corrected for plasma volume shifts). The sessions were clinically uneventful; the system was technically safe and easily handled. In conclusion, short-term LDL hemoperfusion by the DALI proved to be a safe, effective, and simple procedure for the treatment of patients suffering from symptomatic recalcitrant hypercholesterolemia. The present study represents a solid basis for the clinical long-term evaluation of this new technique in the future.     

Therapeutic Apheresis of Immune Diseases in Nephrology Department

Objective. The clinical efficacy of therapeutic apheresis is still controversial. We undertook a retrospective review of apheresis treatment to ascertain its safety and efficacy. Methods. We reviewed 31 patients (13 male, 18 female). Plasmapheresis was performed on 7 patients with hematologic disorders, 5 patients with neurologic disorders, 6 patients with systemic diseases, and 3 patients with Lyell syndrome. Immunoadsorption onto protein A sepharose was evaluated as rescue therapy in 7 patients. Low‐density lipoprotein (LDL) apheresis was performed on 3 patients. Results. There were five mortalities due to serious complications of their primary disease. Most complications were mild such as hypotension and hypocalcemia. Two patients who received LDL apheresis had severe anaphylactic reactions. Apheresis was effective in the remaining 24 patients. Conclusions. The therapeutic apheresis consists of a continuously improving therapeutic method for diseases with high mortality and morbidity, especially in cases with poor outcome by using current medications.     

Low–Density Lipoprotein Apheresis Versus Lipid Lowering Drugs in the Treatment of Severe Hypercholesterolemia: Four Years' Experience

Abstract: Elevated lipoprotein concentrations seem to be linked strongly in a dose dependent manner to an increased incidence of atherosclerosis. A total of 47 patients suffering from severe hyperlipidemia were matched to treatment with LDL apheresis (Baxter, Kaneka, Li–popak; 24 patients, aged 50.2 ±11.5 years), diet, and/or lipid–lowering drugs or with diet and lipid–lowering drugs only (23 patients, aged 48.8 ±11.8 years). After treatment periods of 49.8 ±13.4 months (apheresis group, 2,396 treatment sessions) and 38.6 ± 15.1 months (drug group), the ensuing results revealed significant differences (p <0.0001): –47.3% versus –12.1% for total cholesterol, –46.9% versus –21.8% for LDL, +8.4% versus +0.9% for HDL, –52.0% versus – 13.1% for the LDL/HDL ratio, –36.4% versus –16.2% for triglycerides, and –25.9% versus + 1.5% for lipoprotein (a). In the apheresis group, one patient died of myocardial infarction; in the drug group, there was one nonfatal myocardial infarction and the manifestation of coronary heart disease in 3 cases. There were no severe side effects in either group. All patients in the apheresis group responded to therapy. The present trial suggests that a continuing reduction in serum lipid concentrations may lower, in a dose dependent manner, the risk for development and progression of coronary heart disease. Regarding clinical and laboratory results, LDL apheresis seems to be safe, effective therapy for treatment of severe hyperlipidemia.     

LDL Apheresis in a Homozygous Familial Hypercholesterolemic Child Aged 4.5

Abstract: Preliminary experience with the efficacy and safety of dextran sulfate cellulose low-density lipoprotein (LDL) apheresis for the treatment of a 4.5-year-old girl with homozygous familial hypercholesterolemia and coronary artery disease is reported. The decrease of the most atherogenic apolipoprotein B-containing lipoproteins, low-density lipoprotein (LDL) and lipoprotein(a) (Lp [a]), were in the ranges of 63.1–68.7%, and 52.5–58.6%, respectively. The child tolerated LDL apheresis without any clinically significant complications. Therefore, she was submitted to a long-term program of treatment at intervals of 15 days. The experience suggests the possibility of an early beginning of extracorporeal treatment with LDL apheresis in children severely affected by homozygous or double heterozygous familial hypercholesterolemia.     

Extracorporeal Removal of Lipids by Dextran Sulfate Cellulose Adsorption

Abstract: Extracorporeal removal of low–density lipoprotein (LDL) cholesterol by dextran sulfate adsorption is indicated in patients with diet and drug resistant hypercholesterolemia to prevent or to regress coronary heart disease. Plasma separation is the first step in the process, followed by adsorption of LDL cholesterol and lipoprotein (a) (Lp[aJ) to negatively charged dextran sulfate co–valently bound to cellulose beads. The reduction per treatment in LDL cholesterol is 65–75% and in Lp(a) 40–60%. In most patients one treatment per week is sufficient to reduce mean LDL to 100–150 mg/dl. Minor side effects occur in 2–6% of treatments. Major side effects are rare. In uncontrolled studies long–term treatment was associated with inhibition of progression and induction of regression of coronary artery disease. LDL apheresis by dextran sulfate may increase blood perfusion of some tissues, and preliminary results indicate a beneficial effect on therapy resistant nephrotic syndrome with hypercholesterolemia.     

Long-term efficacy of low-density lipoprotein apheresis for focal and segmental glomerulosclerosis

Recently, there have been reports on the efficacy of low-density lipoprotein (LDL) apheresis (LDL-A) for focal and segmental glomerulosclerosis (FSGS) in pediatric patients. However, there have been few reports on the long-term efficacy of LDL-A for FSGS in such patients. We report here a case of long-term efficacy of LDL-A for FSGS. The patient was a 13-year-old boy with FSGS who presented with steroid-resistant and cyclosporine-resistant nephrotic syndrome and hyperlipidemia. LDL-A was performed 24 times on one year. Following LDL-A, serum concentrations of LDL, very low-density lipoprotein (VLDL), apoprotein B, and vascular endothelial growth factor significantly decreased, and urinary excretion of protein also decreased. In addition, 3 years after LDL-A, the pathology findings on a second renal biopsy had improved. The patient has been in remission from FSGS for 12 years since LDL-A. These findings suggest that LDL-A may be useful in maintaining long-term remission from pediatric FSGS.     

LDL Hemoperfusion-A New Procedure for LDL Apheresis: Biocompatibility Results from a First Pilot Study in Hypercholesterolemic Atherosclerosis Patients

Abstract: Current lipid apheresis techniques can remove atherogenic lipoproteins only from plasma. The initial mandatory separation of plasma and blood cells renders the extracorporeal circuit complex. We recently described the first clinical application of a new lipid adsorber that adsorbs low-density lipoprotein (LDL) and lipoprotein (a) (Lp[a]) directly from whole blood. In continuation of our work, this paper describes the clinical biocompatibility of this new LDL hemoperfusion system. In a 2 center phase II clinical trial, 12 hypercholesterolemic patients suffering from overt coronary or peripheral artery disease were treated once with LDL hemoperfusion. The new LDL adsorber (DALI, Fresenius, St. Wendel, Germany) contained 480 ml of polyacrylate coated polyacrylamide gel. The anticoagulation protocol consisted of an initial heparin bolus followed by an acid citrate dextrose-A (ACD-A) infusion during the treatment. One patient blood volume was treated per session. All sessions were clinically un eventful. No signs of hemolysis or extracorporeal clot formation could be detected, and cell counts remained virtually constant. In a subgroup of patients (n = 4–6), further biocompatibility parameters were studied. Activation of leukocytes (elastase release), thrombocytes (β-thrombo-globulin [β-TG] extrusion), and monocytes (interleukin (IL)-1β and IL-6) were minimal. Complement activation (C3a and C5a generation) was negligible. The chosen anticoagulation protocol was both safe (constant ionized calcium levels) and effective (low thrombin-antithrombin formation). In summary, within the scope of a first pilot study. this new LDL hemoperfusion procedure combined the features of excellent clinical tolerance, good biocompatibility, and ease of handling. Phase III clinical trials will have to show whether these encouraging preliminary results can be corroborated in a larger patient population.     

Extracorporeal treatment of hypercholesterolaemia

Extracorporeal removal of LDL cholesterol (LDL apheresis) hasbeen carried out in patients with diet- and drug-resistant hypercholesterolaemiato prevent or to reduce coronary heart disease. Plasma separationis the first step in all five LDL-apheresis methods presentlyavailable. Plain plasma exchange and double-membrane filtrationare unselective and remove HDL cholesterol and plasma proteins.Adsorption of LDL to dextran sulphate, to LDL antibodies, orprecipitation of LDL by heparin at low pH are more selective.With all methods LDL cholesterol reduction per treatment is60–70%. In most patients one treatment per week is sufficientto reduce mean LDL to 100–150 mg/dl. Minor side-effectsoccur in 10±5% of treatments. Major side-effects arerare. Long-term LDL apheresis increased survival in patientswith homozygous familial hypercholesterolaemia. In heterozygousfamilial hypercholesterolaemia controlled studies regardingsurvival are not available. Uncontrolled trials indicate regressionof coronary artery disease in heterozygotes with drug- and diet-resistantLDL cholesterol > 200 mg/dl. Hence, LDL apheresis is indicatedin all patients with homozygous familial hypercholesterolaemia.LDL apheresis in heterozygous familial hypercholesterolaemiashould be restricted to patients with diet- and drug-resistantLDL cholesterol >200 mg/dl with coronary heart disease and/orother atherosclerotic vascular lesion.     

Lipoprotein(a) Apheresis in Severe Coronary Heart Disease: an Immunoadsorption Method

Lipoprotein(a) (Lp[a]) is associated with an increased cardiovascular risk. It is similar to low-density lipoprotein with an additional molecule of apo A covalently linked to apo B-100 by one disulfide bridge. Apo A is highly homologous to plasminogen. The kringle 4 motive of plasminogen is repeated between 10 and 40 times in apo (a). Currently, there is no drug therapy available to lower Lp(a). Since October 1993, we have carried out over 160 immunoadsorption treatments on 3 patients with elevated Lp(a) as their only risk factor and a history of myocardial infarction. Lp(a) was removed from plasma by sepharose coupled anti-Lp(a) columns. Lp(a) levels were lowered from above 170 mg/dl to below 30 mg/dl immediately after Lp(a) apheresis. To achieve this, the patient's plasma volume had to be treated 2 to 3 times. Nonspecific protein loss during column changes remained negligible. There were no serious unwanted effects during or after treatment. Minor circulatory problems (tachycardia, flush) occurred in 11% of the treatments but only with plasma flow rates above 55 ml/min. In 1 patient, coronary angiography after 2 years and in another patient after 1 year showed no progression. The third patient has not yet had repeat coronary angiography. Like the others, he reported subjective improvement after 1 year of apheresis. It is concluded that Lp(a) apheresis may retard progression of atherosclerosis in patients with selective Lp(a) elevation. Further studies to support this hypothesis are needed.     

Low-Density Lipoprotein Apheresis and Regression of Atherosclerotic Plaque In Vitro

Short-term organ culture and primary cell culture of human aorta were used to study the effect of selective removal of low-density lipoproteins (LDLs) from the surrounding medium (LDL apheresis) on the lipid content of cultured tissue and cells, respectively. LDL apheresis was performed by passing the culture medium through immunosorbent containing agarose-bound goat antibodies against human LDL. LDL apheresis promoted the decrease of lipids of all classes in the cultured atherosclerotic plaque. However, only the cholesteryl ester level, but not free cholesterol, triglyceride, or phospholipid levels, was lowered in the cells cultured from the plaque. One may thus assume that LDL apheresis facilitates regression of lipoidosis by reducing the content of lipids in atherosclerotic lesions.     

Are lipid‐dependent indicators of cardiovascular risk affected by renal transplantation?

Hyperlipoproteinemia has been reported to frequently occur in kidney transplanted patients, thus possibly explaining, at least in part, the increased incidence of cardiovascular disease in this population. To evaluate the impact of renal transplantation (Tx), and related immunosuppressive therapy, on plasma lipoprotein and Lp(a) profile, we selected a cohort of kidney transplanted patients (36 M/14 F; age 33.8 + 12.0 yr, range 13-62) lacking significant causes of hyperlipidemia. All patients received a triple immunosuppressive regimen and showed a stable renal function after Tx (plasma creatinine: 1.36 +/- 0.35 mg/dL). One year after Tx, we found a significant increase of total cholesterol (TC), LDL, HDL, ApoB and ApoA-I (p < 0.005), while plasma triglyceride levels remained unmodified. Lp(a) plasma levels after Tx were within the normal range and displayed a significant inverse relationship with apo(a) size. Noteworthy, LDL/HDL ratio and ApoB/ ApoA-I ratio in kidney transplanted patients were almost superimposable with those of normal controls. Specifically, LDL/HDL ratio significantly decreased in 64% of patients after Tx, due to a prevalent increase of HDL, and was associated with a moderate amelioration of plasma TG. In a multiple linear regression model, post-Tx HDL level was significantly related to recipient's age, gender, BMI and cyclosporine (CyA) trough levels (Adj-R2 = 0.35, p = 0.0002), with gender and CyA trough levels being the better predictors of HDL. In conclusion, immunosuppressive regimens, in themselves, do not appear to significantly increase the atherogenic risk related to lipoproteins. Rather, other factors can affect the lipoprotein profile and its vascular effects in renal transplant recipients.