Plasmapheresis for hypertriglyceridemia: The association between blood viscosity and triglyceride clearance rate

OBJECTIVES

Several factors in double filtration plasmapheresis (DFPP) were associated with triglyceride (TG) clearance rate. This study examines whether baseline whole blood viscosity was a predictor for efficient TG removal.

METHODS

Adult subjects who receiving DFPP for hyperlipidemia in Taoyuan General Hospital from January 2015 to March 2018 were classified into efficient and inefficient TG removal according to TG removal rate ≥50% vs <50%. TG removal rate was defined as following formula: (pre-apheresis TG- post-apheresis TG)/pre-apheresis TG. Whole blood viscosity (WBV) was estimated by following equation: WBV = 0.12 × hematocrit +0.17 × (total protein -2.07). Univariate linear regression was used to assess the association between TG removal rate and WBV. Odds ratios (ORs) and 95% confidence interval (95%CI) for associations between variables and efficient TG removal were evaluated by logistic regression model to including univariate and multivariate adjustment.

RESULTS

From a total of 66 subjects receiving DFPP, 37 subjects reached efficient TG removal. The difference in pre-apheresis TG levels, hematocrit, and WBV between efficient vs. inefficient TG removal groups was 4.1 vs 6.7 mmol/L; 43.1% vs 39.5%; and 6.0cP vs 5.cP (Ps <0.05). After multivariate adjustment, WBC was a significant predictor for efficient TG removal (ORs and 95% CI were 3.192 (1.300-7.838), P < 0.05). The correlation between WBV and extraction of TG was significant (r = -0.255, P = 0.039).

CONCLUSION

Hyperviscosity reduced the efficiency of TG removal in those receiving DFPP.

Lipoprotein apheresis in the management of severe hypercholesterolemia and hyperlipoproteinemia(a)-The Portuguese experience

BACKGROUND

Low-density lipoprotein cholesterol (LDL-C) and lipoprotein(a) (Lp(a)) are established causal risk factors for cardiovascular disease (CVD). Lipoprotein apheresis is often required for treatment of patients with a high risk for CVD due to hypercholesterolemia and/or hyperlipoproteinemia(a).

AIM

To describe our experience with lipoprotein apheresis in patients with severe hypercholesterolemia or with hyperlipoproteinemia(a).

METHODS

We retrospectively investigated patients treated with Lipoprotein apheresis using direct adsorption of lipoproteins (DALI) technique, between December 2008 and March 2018, in our center. Adverse events, acute and long term reductions in lipid parameters were analyzed.

RESULTS

Between December 2008 and March 2018, a total of 950 treatments were performed in five patients, four with heterozygous familial hypercholesterolemia (HeFH), all on maximally tolerated cholesterol-lowering drug therapy and in one patient with hyperlipoproteinemia(a) and progressive CVD. In the four patients with HeFH we obtained mean acute reductions in LDL-C and non-high-density lipoprotein cholesterol (non-HDL-C) of 62.0 ± 7.8% and 60.4 ± 6.8%, respectively. Regarding long-term efficacy we achieved a mean reduction of 43.1% in LDL-C and of 41.2% in non-HDL-C. In the patient with hyperlipoproteinemia(a) we attained mean acute reductions of 60.4 ± 6.4% in Lp(a) and of 75.4 ± 7.3% in LDL-C per session and long term reductions in Lp(a) and LDL-C of 67.4% and 40.5%, respectively. Adverse events were recorded in only 1.2% of treatments.

CONCLUSION

Lipoprotein apheresis is an efficient and safe treatment in severely hypercholesterolemic patients who are refractory to conservative lipid-lowering therapy or with hyperlipoproteinemia(a) and progressive CVD.

Optimization of therapeutic procedure during LDL-apheresis - verification of the computerized model in clinical practice

LDL-apheresis is a very effective method in the treatment of resistant hypercholesterolemia when other therapies fail. To maximize the efficacy of the use of LDL-absorbers, we created a computerized model. The aim of this study is to verify it in clinical use.

PATIENTS AND METHODS

A therapeutic technique of immunoadsorption was used, applying a pair of Lipopak columns (Pocard, Russia). Plasma was separated by a continuous-flow plasma separator (Cobe Spectra, USA); adsorption was controlled by adsorption-desorption equipment Adasorb (Medicap, Germany). 494 LDL-apheresis procedures had been performed in nine patients with primary hypercholesterolemia in the earlier, initial study; 47 other procedures (202 therapeutic cycles) were used in this verification study. The program for procedure planning uses Microsoft Excel for Windows. Complex metabolism of the LDL-cholesterol was neglected (owing to the short-time period of the procedure) and the procedure calculated as continuous filtration. The input enterer into the program includes basic patient data (mass, height, sex and initial plasma LDL level in mmol/L).

RESULTS

The results show a very good match between calculated levels and the real laboratory results in most procedures, but in some procedures we observed minor differences (0.05 mmol/L), which was caused by procedure adjustments due to technical reasons. However, some methodological and medical details must be carefully observed (initial cholesterol level, correct calculation of plasma volume, and the precise capacity of adsorbers that must not be overshot); as they influence the correct match between calculated and real results significantly.

CONCLUSIONS

Although our software uses a fairly simplified model of the LDL-cholesterol kinetics during the LDL-apheresis, it is providing a great aid in the procedure planning. It is also suitable for practical use because it only requires a few commonly used and readily available input values.

Optimization of the therapeutic procedure during LDL-apheresis—a computerized model

LDL-apheresis is a very effective method for the treatment of resistant hypercholesterolemia when other therapy (dietary, or medication) fails. To maximize the efficacy of the LDL-absorbers we aimed to create a computerized model.

PATIENTS AND METHODS

The therapeutic technique of immunoadsorption was used, applying a pair of columns, the Lipopak, Pocard, Russia. Plasma was separated by a continuous-flow plasma separator, the Cobe Spectra, USA; adsorption was controlled by adsorption-desorption equipment, ADA, Medicap, Germany. 494 LDL-apheresis procedures (treatment interval 17.5+/-1.6 days) were used to treat nine patients with primary hypercholesterolemia followed during the consecutive 3.6+/-0.5 years. Metabolism of LDL-cholesterol is known to be multicompartmental and dynamic, but for the short-time period of the procedure it can be simplified and one can calculate the procedure as a continuous filtration. We developed a program for procedure planning, using Microsoft Excel for Windows. Inputs inserted into the program include only basic patient data (mass, height, sex and initial plasma LDL level in mmol/l).

RESULTS

The results show a very promising match between our planning of the procedures and the real laboratory results. The drop in calculated vs real plasma LDL-cholesterol level differ no more than +/-10%.

CONCLUSIONS

Although our software does not take into account many well known details about the metabolism of cholesterol, in given conditions it can provide a fairly precise prediction of procedure parameters. It is also suitable for practical use, because it requires only a few commonly used and readily available input values. Immunoadsorption with Pocard absorbers is a potent and safe method of therapy in indicated patients.

Direct adsorption of low-density lipoprotein and lipoprotein(a) from whole blood: results of the first clinical long-term multicenter study using DALI apheresis

Direct adsorption of lipoproteins (DALI) is the first low-density lipoprotein (LDL)-apheresis technique by which atherogenic LDL and lipoprotein(a) (Lp(a)) can be selectively removed from whole blood without plasma separation. The present study was performed to evaluate the efficacy, selectivity and safety of long-term DALI apheresis. Sixty-three hypercholesterolemic coronary patients were treated by weekly DALI sessions. Initial LDL-cholesterol (C) plasma levels averaged 238 +/- 87 mg/dl (range 130-681 mg/dl). On average, 34 sessions (1-45) were performed processing 1.5 patient blood volumes. The primary aim was to acutely reduce LDL-C by >or=60% per session. To this end, three different adsorber sizes could be employed, i.e., DALI 500, 750, and 1000, which were used in 4, 73, and 23% of the 2156 sessions, respectively. On average, 7387 ml of blood were processed in 116 min per session. This resulted in the following mean acute changes: LDL-C 198 --> 63 mg/dl (-69%), Lp(a) 86 --> 32 mg/dl (-64%), triglycerides 185 --> 136 mg/dl (-27%). HDL-C (-11%) and fibrinogen (-15%) were not significantly influenced. The mean long-term reduction of LDL-C was 42% compared to baseline while HDL-C slightly increased in the long run (+4%). The selectivity of LDL removal was good as recoveries of albumin, immunoglobulins, and other proteins exceeded 85%. Ninety-five percent of 2156 sessions were completely uneventful. The most frequent adverse effects were hypotension (1.2% of sessions) and paresthesia (1.1%), which were probably due to citrate anticoagulation. Access problems had to be overcome in 1.5%, adsorber and hardware problems in 0.5% of the sessions. In this multicenter long-term study, DALI apheresis proved to be an efficient, safe, and easy procedure for extracorporeal LDL and Lp(a) elimination.

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.

DALI low-density lipoprotein apheresis in homozygous and heterozygous familial hypercholesterolemic patients using low-dose citrate anticoagulation

The purpose of this study was to clarify the efficacy and safety of direct adsorption of lipoprotein low-density lipoprotein apheresis (DALI LDL apheresis) in patients with severe homozygous and heterozygous familial hypercholesterolemia who showed minor adverse effects during treatment with the usual DALI configuration (AC 1:20) through the use of a new system with low-dose citrate anticoagulation (AC 1:40) developed in order to minimize citrate-related adverse effects. Serum total cholesterol and LDL-cholesterol (LDL-C) showed a decrease of 57% to 61%, and 62% to 67%, respectively, in the 2 patients. Serum lipoprotein (a) (Lp[a]) was higher in the homozygous patient (Patient 1: MD) and within the normal range in the heterozygous patient (Patient 2: ES). In the former, Lp(a) was reduced by 52%. Serum high-density lipoprotein cholesterol (HDL-C) showed a statistically insignificant acute reduction: 15% to 19%. The observed reduction is mainly related to the well-known effect of hemodilution. The cardiovascular risk (total cholesterol/HDL-C) was reduced in both patients (46% to 54%) as expected. Serum triglycerides were reduced by 33% to 49%. The mean blood volume processed per session was 7,600 ml. Fifteen treatments for each patient have successfully been completed without the appearance of any clinically significant subjective and objective symptoms related to treatment with the new system.

Direct adsorption of lipoproteins from whole blood by DALI apheresis: technique and effects

Low-density lipoprotein (LDL) apheresis can drastically reduce atherogenic lipoproteins in coronary patients in whom LDL and lipoprotein (a) (Lp[a]) cannot be sufficiently reduced by conservative therapy. LDL and Lp(a) adsorption by polyacrylate/polyacrylamide (DALI) is the simplest procedure for clinical LDL apheresis to date. DALI was first applied in patients in 1994 and introduced into clinical routine in 1996. It is the first LDL-hemoperfusion system, i.e., it adsorbs LDL and Lp(a) directly from whole blood. This markedly simplifies the extracorporeal circuit, the handling of the system, and reduces significantly staff time and, especially at higher blood flow rates, treatment time. Its features are high selectivity and capacity of lipoprotein removal (maximum about 8 g low-density lipoprotein cholesterol per session). Using citrate anticoagulation, good biocompatibility is evidenced by the lack of cell losses, hemolysis, thrombotic events, and complement activation. Some clotting factors of the intrinsic system are also adsorbed. There is significant bradykinin activation that, however, does not cause problems in most patients if angiotensin converting enzyme inhibitor medication is avoided. In a first long-term study, 93% of sessions were uneventful. Major side effects were citrate-induced paresthesias (1.3%) and hypotension (0.8%). To date, more than 25,000 DALI sessions have been performed all over the world.

Lipid reductions by low-density lipoprotein apheresis: a comparison of three systems

There are currently three established low-density lipoprotein (LDL) apheresis systems: immunoadsorption, heparin-induced extracorporeal LDL precipitation (HELP), and dextran sulfate. We treated the same patient with all three systems and compared the lipid reductions achieved. A total of 135 consecutive treatments were studied, 57 with immunoadsorption, followed by 30 with HELP and 48 with dextran sulfate adsorption. The mean plasma volume (mean +/- SD) treated was 4.9 +/- 0.05, 3.08 +/- 0.091, and 3.39 +/- 0.71 L, respectively. The LDL-cholesterol (LDL-C) reduction was 75.5% +/- 7.4%, 61.6% +/- 5.1%, and 57.1% +/- 12.4%, respectively (P < .001 for immunoadsorption vHELP and dextran sulfate). The mean removal efficiency (mass removed/plasma volume treated) for LDL-C was 1.0 +/- 0.12, 1.42 +/- 0.25, and 1.15 +/- 0.21 g/L, respectively (P < .001 for HELP v immunoadsorption and dextran sulfate). The mean LDL-C plasma concentration before apheresis was 199 +/- 23.9, 201 +/- 25.7, and 186 +/- 28 mg/dL, respectively (P < .001 for dextran sulfate adsorption v immunoadsorption and HELP). Among the three LDL apheresis systems, immunoadsorption caused the greatest percent reduction in LDL-C, while HELP eliminated LDL-C from the plasma most efficiently. Dextran sulfate was similar to HELP in terms of LDL-C reduction, and its removal efficiency was similar to immunoadsorption. Dextran sulfate was also associated with the lowest pretreatment plasma LDL-C concentration.

The rebound of lipoproteins after LDL-apheresis. Kinetics and estimation of mean lipoprotein levels

We studied the rebound of lipoproteins in 20 hypercholesterolemic men [mean total cholesterol (TC) levels 9.6+/-1.8 mmol/l] after LDL-apheresis (LA) to determine the rate of recovery and the change in cholesterol synthesis, and to find a uniform estimation for time-averaged levels. After 10-20 months on biweekly LA using dextran sulfate cellulose columns and concomitant simvastatin administration, time-averaged levels (+/-SD) measured by integration of the area under the curve were as follows: TC 4.4+/-1.0 mmol/l, LDL cholesterol (LDL-C) 2.5+/-1.0 mmol/l, apolipoprotein B (apo B) 1. 3+/-0.3 g/l, triglycerides (TG) 1.7+/-0.7 mmol/l, HDL-C 1.1+/-0.2 mmol/l, and lipoprotein(a) [Lp(a)] 53.7+/-49.4 mg/dl. Mean acute reductions in TC, LDL-C, apo B, Lp(a), and TG were 61, 77, 75, 76, and 62%, respectively. HDL-C levels were not influenced. Median recovery half times for TC, LDL-C, apo B, and Lp(a) were 3.0, 4.0, 2. 3, and 3.5 days, respectively. The rebound of Lp(a) was identical to LDL-C, in 12 and 13 days post-treatment, respectively, whereas apo B and TC returned to pre-treatment levels in 7.5 and 10 days, respectively, due to the fast rebound of VLDL particles. Notwithstanding these differences, time-averaged levels (C(AVG)) could be estimated uniformly for the four latter parameters with the formula: C(AVG)=C(MIN)+0.73(C(MAX)-C(MIN)), where C(MAX) and C(MIN) are the immediate pre- and post-treatment levels. During long-term treatment the whole-body cholesterol synthesis was increased as measured by the ratio lathosterol to cholesterol of 3.24+/-1.49 mmol/mmol, whereas no further transient increase in the recovery period after LA was found. In conclusion, long-term LA and simvastatin therapy induced acute and chronic changes in lipids and lipoproteins showing the feasibility of biweekly treatment. It was shown that time-averaged levels, as a measure for the effective plasma levels, can be accurately estimated from pre- and post-treatment levels only.

Low density lipoprotein apheresis in treatment of hyperlipidemia: experience with four different technologies

The prognosis of patients suffering from severe hyperlipidaemia (HLP), sometimes combined with elevated lipoprotein (a) levels, and coronary heart disease (CHD) refractory to diet and lipid lowering drugs is poor. A new therapeutic option for such patients is regular treatment with low density lipoprotein (LDL) apheresis. In total 33 patients (16 males, 17 female, aged 43.8+/-14.3 years), suffering from severe HLP resistant to diet and lipid lowering drugs, were treated for 62.3+/-21.3 (range, 1-113) months with LDL-apheresis. Four different LDL-apheresis systems were used: the dextran sulfate adsorption for 28 of 33 (Liposorber, Kaneka, Japan), immunoadsorption for 2 of 33 (Therasorb, Baxter, Germany), LDL-hemoperfusion for 2 of 33 (Dali, Fresenius, Germany), and the immunoadsorption system with special antilipoprotein (a) columns for 1 of 33 patients (Lipopak, Pocard, Russia). Before applying LDL-apheresis, 27 of 33 patients suffered from CHD with severe angina pectoris symptoms, a history of myocardial infarction or coronary artery venous bypass (CAVB). With LDL-apheresis, reductions (p < 0.05) of 46% for total cholesterol, 49% for LDL, 28% for Lp(a), and 38% for triglycerides were reached. Severe side-effects, such as shock or allergic reactions, were very rare (0.5%). In the course of treatment an improvement in general well-being and increased performance were experienced in 29 of 33 patients. In 23 of 27 patients suffering from CHD, a reduction of 60 to 100% of nitrate medication was observed. Regarding the different apheresis systems used, there were no significant differences with respect to the clinical outcome and concerning total cholesterol, LDL, HDL, and triglyceride concentrations. But, in respect to elevated lipoprotein (a) levels, the immunoadsorption method using special anti-lipoprotein (a) columns seems to be the most effective (-57% versus -25% [Kaneka, p < 0.05] or -23% [Baxter, p < 0.05]). The present data clearly demonstrate that treatment with LDL-apheresis in patients suffering from severe HLP, refractory to maximum conservative therapy, is effective and safe in long-term application.

Analysis of the long-term efficacy and selectivity of immunoadsorption columns for low density lipoprotein apheresis

Immunoadsorption low density lipoprotein (LDL) apheresis is performed with reusable columns containing anti-apolipoprotein B(ApoB) antibodies. We analyzed their long-term efficacy and selectivity. Performance over 60 treatment sessions of six pairs of immunoadsorption LDL apheresis columns was evaluated by analysis of variance using the removal of total cholesterol and ApoB to assess efficacy and the ratio of total cholesterol/high density cholesterol removed to assess selectivity. The removal of cholesterol did not vary significantly with treatment number. The mass of ApoB removed increased significantly (p = 0.002), and the mass of ApoB removed per volume unit of processed plasma showed a trend (p = 0.065) toward an increase with treatment number. Both parameters correlated with the serum ApoB concentration before treatment, which also increased significantly (p = 0.0007) with treatment number. No significant variation of selectivity was found. The efficacy of the LDL apheresis immunoadsorption columns did not decrease after 60 treatment sessions. The columns' selectivity also remained unchanged.

DALI-the first human whole-blood low-density lipoprotein and lipoprotein (a) apheresis system in clinical use: procedure and clinical results

BACKGROUND

The DALI low-density lipoprotein (LDL) apheresis system is the first whole-blood apheresis system in regular clinical use. DALI stands for direct adsorption of lipoproteins, which describes the basic principle of operation of this newly developed LDL apheresis procedure.

METHODS

The selective removal of LDLs and lipoprotein (a) [Lp(a)] is performed in human whole blood by adsorption onto polyacrylate-coated polyacrylamide beads in an adsorber. This article describes the results of the first open multicentre clinical trial in 14 patients in whom the safety and the efficacy of the system were tested. All patients were treated on average 17 times on a weekly basis. In total, 238 sessions were carried out during the study without severe side-effects. On average, 7675 mL of the patients' whole blood was processed in about 2 h. Anticoagulation in the extracorporeal system was carried out by first giving a heparin bolus followed by continuous addition of an acid citrate dextrose (ACD-A) infusion during the treatment.

RESULTS

The processing of nearly 1.6 times the patient blood volumes resulted in a reduction in the median LDL-cholesterol level by 66-77% (dependent on the system configuration). The Lp(a) concentrations were reduced by 59-73% (dependent on the system configuration). HDL-cholesterol, blood cell count and the other clinical parameters were not significantly affected.

CONCLUSION

Based on this short-term evaluation, the DALI apheresis system is a well-tolerated, effective and simple way of reducing LDL and Lp(a) in human whole blood. The system has been introduced to clinical practice. However, to use the DALI apheresis system in clinical routine, further evaluation of long-term effects is required.

The effect of selective low-density lipoprotein apheresis on plasma lipoperoxides and antioxidant vitamins in familial hypercholesterolemic patients

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder characterized by a lifelong elevation in the concentration of low-density lipoprotein (LDL) bound cholesterol in blood by cholesterol deposits and by early coronary artery disease. The LDL apheresis technique has been introduced with the goal of reducing LDL cholesterol levels, thereby preventing the development of atherosclerosis. The literature on LDL apheresis reports 2 different facets, the therapeutic aspect associated with the lessening of LDL concentration and the initiation of a peroxidation process associated with the biocompatibility of the artificial membrane. Lipid and protein peroxidation gives rise to toxic and atherogenic hydroperoxide, mostly lipid hydroperoxides, and derivative compounds, which may offset the benefit of the procedure. In this paper, plasma hydroperoxide levels are determined along with the elevation of the serum and LDL antioxidant status in hypercholesterolemic patients before and following repeated LDL apheresis sessions. Hydroperoxide concentration has been expressed both in terms of plasma volume and LDL concentration. A highly significant increase in LDL lipid hydroperoxides is demonstrated when expressed in terms of LDL concentration and is associated with the LDL apheresis procedure. The usefulness of antioxidant supplementation in LDL apheresis is discussed.

LDL hemoperfusion--a new procedure for LDL apheresis: first clinical application of an LDL adsorber compatible with human whole blood

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.

LDL apheresis in clinical practice: long-term treatment of severe hyperlipidemia

Thirty patients (13 males, 17 females) suffering from familial hypercholesterolemia resistant to diet and lipid-lowering drugs were treated for 48.7 +/- 19.2 months (range, 2-87 months) with low density lipoprotein (LDL) apheresis. Three different systems (dextran sulfate adsorption for 27 of 30 [Kaneka, Liposorber, Japan], immunoadsorption system for 2 of 30 [Baxter, Therasorb, Germany], immunoadsorption system with special lipoprotein a [Lp(a)] columns for 1 of 30 patients [Lipopak, Pocard, Russia]) were applied. Before LDL apheresis 24 of 30 patients suffered from coronary heart disease (CHD) with angina symptoms. With LDL apheresis, reductions of 46% for total cholesterol, 49% for LDL, 30% for Lp(a), and 38% for triglycerides were reached. Severe side effects such as shock or allergic reactions were very rare (0.5%). In the course of treatment, an improvement in general well-being and increased performance were experienced in 27 of 30 patients. A 60 to 100% reduction of nitrate medication was observed in 17 of 24 patients. Regarding the different apheresis systems used, at the end of the trial there were no significant differences with respect to the clinical outcome experienced by the patients and concerning total cholesterol, LDL, high density lipoprotein, and triglyceride concentrations. But to reduce high Lp(a) levels, the immunoadsorption method with special Lp(a) columns seems to be the most effective (-57% versus 25% [Kaneka] and 23% [Baxter]). The present data clearly 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.

Lipid apheresis: from a heroic treatment to routine clinical practice

Lipid apheresis has developed from a heroic treatment into a routine clinical therapy and currently is the major indication for performing extracorporeal plasma therapy. Whereas it was once reserved for patients with homozygous familial hypercholesterolemia, today it has a place in the secondary prevention of severe coronary heart disease when low-density lipoprotein (LDL)-cholesterol level exceeds 150 mg/dl, despite conservative treatment, in any type of primary hypercholesterolemia. Unselective plasma exchange has been replaced by a variety of selective procedures. The efficacy of the treatment can be maximized by combining LDL apheresis with the use of cholesterol synthesis enzyme inhibitors. Clinical studies have shown that drastic cholesterol reduction can result in regression of coronary atherosclerosis as well as in reduced cardiac morbidity and mortality. Technical progress comprises improved selectivity, online regeneration of adsorbers, and LDL adsorption from whole blood. Recently, a new LDL hemoperfusion procedure was successfully tested in a clinical pilot study; blood is passed directly over a lipid sorbent without prior plasma separation. If this system is demonstrated to be safe and effective in clinical Phase III trials, a further qualitative step in the rapid development of LDL apheresis will have made.

Heparin-induced extracorporeal low-density lipoprotein precipitation and low-density lipoprotein chemoadsorption onto dextran sulfate: a comparison

Both heparin-induced extracorporeal low-density lipoprotein precipitation (HELP) and dextran sulfate (DS) apheresis are potent tools for acute and long-term risk factor reduction in the secondary prevention treatment of coronary patients suffering from recalcitrant hypercholesterolemia. They combine high efficacy and selectivity of risk factor removal. Whereas LDL cholesterol and lipoprotein (a) adsorption onto DS offers the advantage of an unlimited treatable plasma volume and somewhat easier handling, HELP reduces fibrinogen more effectively and does not interfere with angiotension-converting enzyme (ACE) inhibitors. Both systems can improve blood rheology and induce regression or stabilize coronary lesions. In an uncontrolled trial, HELP reduced the incidence of myocardial infarction. To date, no controlled prospective trials have been performed comparing the two systems with respect to their long-term risk factor reduction and their effect on coronary lesions, morbidity, and mortality.

State of the art of lipid apheresis

Currently, 5 different lipid apheresis procedures are available for routine clinical treatment of hypercholesterolemic 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 based on immunologic or electrostatic interactions: immunoadsorption using anti-low-density lipoprotein (LDL) antibodies, chemoadsorption onto dextran sulfate, and heparin-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.