Decreased low-density lipoprotein oxidation after repeated selective apheresis in homozygous familial hypercholesterolemia.

Familial hypercholesterolemia was the first genetic disorder recognized to cause myocardial infarction. Patients with homozygous familial hypercholesterolemia have rapidly progressive coronary atherosclerosis with angina pectoris, myocardial infarction, or sudden death at a young age. Selective apheresis on dextran sulfate cellulose columns reduces mortality and may induce regression of coronary lesions. These patients have both increased levels and prolonged circulation residence time of low-density lipoprotein (LDL), which is not removed by cellular receptor. LDL oxidation may play a pivotal role in atherogenesis. LDL undergoes oxidation before being taken up by macrophages and then transformed into arterial wall foam cells. The aim of this study was to investigate LDL oxidation in eight homozygous patients with familial hypercholesterolemia during repeated LDL apheresis. LDL lipid peroxidation, estimated by conjugated-diene absorbance at 234 nm, lipid peroxides, and malondialdehyde showed an increased resistance against oxidation after repeated LDL apheresis. This phenomenon was also observed in the oxidative indexes of protein moiety of LDL (apolipoprotein-B100 fragmentation, trinitrobenzenesulfonic acid reactivity, and electrophoresis agarose mobility). Similarly, cholesteryl esterification was decreased after LDL apheresis. Thus selective LDL apheresis not only decreases the pool of LDL, but it also induces changes that render LDL less susceptible to oxidation. This phenomenon might contribute to reduce coronary atherosclerosis and thus mortality of these particular patients.

Combined treatment with amphotericin-B and granulocyte transfusion from G-CSF-stimulated donors in an aplastic patient with invasive aspergillosis undergoing bone marrow transplantation.

Granulocyte transfusions from G-CSF stimulated donors were added to standard anti-infective treatment in preparation for and during allogeneic bone marrow transplantation in a young man affected by very severe acute aplastic anemia and invasive aspergillosis. Nine concentrates with a mean neutrophil content of 18.7 x 10(9)/L (2.6 x 10(8)/kg patient b.w.) were transfused before and after marrow infusion. An impressive clinical improvement was noticed after each granulocyte transfusion, although this was not always paralleled by a neutrophil increase in the peripheral blood. Engraftment (N > 0.5 x 10(9)/L and Plt > 25 x 10(9)/L) was verified at +16 and +40 days, respectively. The patient is currently in complete hematological and microbiological remission 14 months after transplantation. Granulocyte apheresis from G-CSF stimulated donors provides a high number of activated neutrophils. At the dose given (300 micrograms/day) donor tolerance to G-CSF was excellent. This new approach is indicated when life-threatening infections develop in patients exposed to prolonged severe neutropenia.

Correction of erythrocyte shape abnormalities in familial hypercholesterolemia after LDL-apheresis: does it influence cerebral hemodynamics?

It is well known that red blood cells incubated in low-density lipoprotein (LDL)-rich medium show shape abnormalities that revert to normal after reincubation in normal plasma. Patients with homozygous familial hypercholesterolemia (HFH) have an increased percentage of abnormally-shaped erythrocytes (mostly stomatocytes, knisocytes, and crenated cells) compared to normocholesterolemic controls: 7.73+/-0.96 versus 3.52+/-0.52 (mean+/-SEM; P = 0.001). To confirm the role of high LDL concentration in inducing red cell shape abnormalities we determined the percentage of abnormally shaped erythrocytes in seven HFH patients 1 day after the procedure of LDL-apheresis with a 40% cholesterol decrease. A reduction in kniscocytes, stomatocytes, and crenated cells was observed in the patients treated by LDL-apheresis (P < 0.01). To investigate the possible benefit of a reduction in erythrocyte shape abnormality on cerebral hemodynamics, cerebral flow velocity, as evaluated by transcranial Doppler, was evaluated concomitantly and found to be remarkably increased after apheresis (P < 0.01). No significant change in hematocrit, plasma viscosity, blood viscosity, mean pressure, or cardiac output was detected, 1 day after apheresis. An inverse correlation was demonstrated (r = 0.55; P = 0.04) between changes in the percentage of knisocytes+stomatocytes +crenated cells and percent changes in middle cerebral artery peak systolic velocity. The correction of erythrocyte shape abnormalities after LDL-apheresis might be related to dramatic changes in plasma phospholipid concentration and proportion occurring after this procedure in HFH patients. The reduction of erythrocyte shape abnormalities could contribute, together with other hemorheological factors, to the improvement of cerebral hemodynamics after LDL-apheresis.

[LDL oxidation in homozygous familial hypercholesterolemia: effects of selective LDL-apheresis treatment]. / Ossidazione delle LDL nell'ipercolesterolemia familiare omozigote; effetti della terapia con LDL-aferesi selettiva.

Homozygous familial hypercholesterolemia (HFH) results from a mutation affecting both the structure and function of a cell surface receptor that removes low density lipoproteins (LDL) from plasma. The disorder is characterized by autosomal dominant inheritance, a lifelong elevation in the concentration of LDL-bound cholesterol in blood and by cholesterol deposits that form xanthomas and early coronary artery disease. HFH patients, as a result of the increased levels and prolonged residence time of LDL in plasma, have a strong tendency toward accumulation of LDL-cholesterol in the arterial wall causing premature atherosclerosis. Selective LDL-apheresis (LA) on dextran/sulphate cellulose columns is the best therapy reducing mortality of these patients. We previously showed that prolonged lifelong enhanced LDL oxidation in HFH. LDL undergo oxidation before being taken up by macrophages then transformed into foam cells. At the present time, the relevance of the in vitro macrophages studies to the accumulation of cholesterol esters in scavenger cells of HFH patients is not yet established. The aim of this study was to investigate LDL oxidation, induced by xanthine (2 mM)+xanthine oxidase (100 mU), and cholesterol esterification in macrophages, in 8 HFH patients before and after LA. LDL peroxidation by conjugated-diene absorbance showed an increased resistance against oxidation after LA: lag time 129 +/- 25 vs 112 +/- 27 min, p < 0.05; diene production 9.1 +/- 2.1 vs 13.9 +/- 2.5 nM/min/mg LDL, p < 0.01. Peroxidation was also evaluated from lipid peroxides (158 +/- 34 vs 57 +/- 18 nM/mg protein after LA, p < 0.05) and malonyldialdehyde (38 +/- 12 vs 27 +/- 8 nM/mg protein after LA, p < 0.05) content. When oxidized LDL was run on polyacrylamide gel extensive apo-B100 fragmentation was observed in LDL before LA, vs a less fragmentation after LA. A similar reduction was obtained in LDL agarose mobility after LA (1.7 +/- 0.2 vs 2.5 +/- 0.2, p < 0.05). Cholesterol esterification in mouse peritoneal macrophages was also decreased after LA (8.5 +/- 1.8 vs 14.6 +/- 2.7 nM/mg cell protein/12 hours, p < 0.05). Vitamin E content of LDL (mg/g protein) was increased after LA (4.44 +/- 1.0 vs 3.9 +/- 1.2, p < 0.05). Thus, selective LA, not only decreases the pool of LDL, but it also induces changes that render LDL less susceptible to oxidation and decreased high cholesterol esterification in macrophages. The prevention of these mechanisms by LA contributes actively to retard atherogenesis in HFH patients.

Experience of computer-aided management of hemapheresis unit.

Several programs are available for blood banks management but none of them is particularly made for hemapheresis. We studied a data base application able to manage any aspect of hemapheresis unit activity. The programming general criteria were: 1) easiness of use even for people without any previous experience in using Personal Computers; 2) maximum saving time in operating; 3) easily modifiable system in reply to problems or new needs; 4) automatic checks in order to have the highest automation together with the smallest error risk; 5) quick view on state of activity and on material consumption; 6) simplification of donor recruitment. After a three year long experience, we describe our program structure in order to give a basis for the development of a standardized management system which is useful for different needs and open to future applications of blood cell separators.

Organization and technical problems of LDL-apheresis.

The Authors consider problems related to technique and organization of LDL-Apheresis with respect to some particular aspects. They evaluate: a) Technical complexity of procedures both in devices to use and in staff preparation; b) Length of treatment which conditions the other fields of activity; c) Problems in management treatments periodicity; d) Usually high cost of this kind of procedures; e) Problems related to vascular accesses; f) Problems related to pediatric patients, both for their low weight and vascular accesses; g) Management of cardio-vascular complications; h) Difficulties in evaluation of regression of vascular lesions. Finally, it is particularly difficult the management of psychological aspects related to somatic symptoms of the disease and to the acceptance of treatment.

Project of computer-aided management of therapeutical apheresis.

UNLABELLED: The great increase in hemapheresis units activity that occurred during the last years caused the need for a computer-aided management (1, 2). We present a project for a data base system able to manage therapeutical apheresis (3). The program consists of five sections. a) Patient's file card: it allows to record anamnesis, examination and blood test results easily and under computer's guidance. b) Choice of therapeutic protocol: Therapeutic protocol is fixed in this section (device to be used, apheretic method, plasma volume to be processed, blood tests before and after apheresis). c) PROCEDURES: It provides procedure's data entry and guides the operator during the treatment on the ground of therapeutical protocol. d) Data processing: It allows statistics on data placed in the data base. e) Registers: It includes both a general register and the possibility of search by disease, device and method.

Cerebral blood flow velocity and systemic vascular resistance after acute reduction of low-density lipoprotein in familial hypercholesterolemia.

BACKGROUND AND PURPOSE: Low-density lipoprotein apheresis is currently used for the treatment of familial hypercholesterolemia, an inherited disorder of metabolism associated with premature development of cardiovascular disease. We wanted to evaluate cerebral blood flow velocity, cardiac output, and systemic vascular resistance in patients with familial hypercholesterolemia before and after low-density lipoprotein apheresis. METHODS: Ten patients (age range, 14 to 46 years; 4 males, 6 females) with familial hypercholesterolemia (8 homozygotes, 2 heterozygotes) and 10 healthy control subjects of comparable age and sex distribution participated in the study. Low-density lipoprotein apheresis by dextran sulfate was performed in 8 patients (7 homozygotes, 1 heterozygote). Six patients (4 homozygotes, 2 heterozygotes) underwent a procedure of extracorporeal erythrocyte filtration with the same extracorporeal volume as for low-density lipoprotein apheresis, but with the exclusion of the passage of plasma through the dextran sulfate column. Cerebral blood flow velocity (transcranial Doppler), cardiac output, and systemic vascular resistance (electric bioimpedance cardiography) were determined by noninvasive techniques before and 1 day and 7 days after low-density lipoprotein apheresis or extracorporeal erythrocyte filtration. Plasma and blood viscosities were measured at the same time. RESULTS: Before apheresis, mean and diastolic cerebral flow velocities were abnormally low in hypercholesterolemic patients (P < .01 and P < .02 vs healthy control subjects, respectively). After apheresis, low-density lipoprotein cholesterol was lowered by 40% to 60% from baseline, and cerebral blood flow velocities (mean, systolic, and diastolic velocities) were increased (P < .01). Cardiac output, systemic vascular resistance, and viscosity values were not significantly modified. Extracorporeal erythrocyte filtration (without passage of plasma through the dextran sulfate column) did not modify serum lipids, hemodynamic parameters, or viscosity values. CONCLUSIONS: Low-density lipoprotein apheresis produces potentially useful hemodynamic effects. They are not adequately explained by changes in blood viscosity alone and might reflect a restoration of endothelium-mediated vasodilation, which is inhibited by high concentrations of low-density lipoprotein.

Treatment of severe hypercholesterolaemia by LDL-apheresis.

The most severe forms of hypercholesterolaemia scarcely respond to diet and conventional drugs administration and need, therefore, alternative treatments. Terapeutic Plasma Exchange demonstrated an improved survival of subjects with Familial Hypercholesterolaemia (FH) in spite of its limitations. Semi-selective and selective techniques have been developed in order to remove LDL cholesterol alone. We studied the efficiency in LDL removal both of membrane filtration as of dextrane sulphate adsorption on 14 FH patients, performing 302 procedures. Cholesterol extraction with the different methods was in the range of 40-65%. Mean cholesterol level was reduced from 7% to 64% depending on the protocol used. The procedures were all performed on an outpatient basis. Side effects occurred rarely and were always of not serious degree. The short and the middle term clinical effects of LDL-Apheresis are then evaluated.

Hemostatic variables in homozygous familial hypercholesterolemia. Effect of regular plasma cholesterol removal by low density lipoprotein apheresis.

Plasma levels of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) and the in vitro ability of platelets to aggregate and of monocytes to express procoagulant (tissue factor) activity (PCA) were evaluated in five patients who are homozygous for familial hypercholesterolemia (FH) before and after a single and a regular 5-month cholesterol removal by low density lipoprotein (LDL) apheresis. The biweekly procedure resulted in a 25% to 30% reduction (approximately 150 mg/dl) in total and LDL cholesterol (both were greater than 550 mg/dl at the beginning of the study). The basal levels of t-PA antigen and fibrinolytic activity before and after 10 minutes of venous stasis, basal PAI activity, and PAI-1 antigen were comparable to controls and were not affected by LDL apheresis. Likewise, regardless of the cholesterol removal, the PCA of freshly isolated monocytes and that of monocytes incubated with lipopolysaccharide did not differ from control values. Finally, the pre-apheresis sensitivity of platelets to adenosine diphosphate, arachidonic acid, and collagen was 1.5 to 2 times the normal value. This ratio was unchanged throughout the 5-month procedure. We conclude that fibrinolysis and monocyte PCA are normal in FH patients, whereas platelet aggregation is abnormally high, and none of these parameters is significantly affected by a 25% to 30% reduction in total and LDL cholesterol by LDL apheresis. Furthermore, our data suggest that removal of cholesterol from plasma by LDL apheresis is important for gaining insight into the mechanisms involved in the ischemic complications of arteriosclerosis in FH patients.

Hemodynamic changes in the peripheral circulation after repeat low density lipoprotein apheresis in familial hypercholesterolemia.

Repeat low density lipoprotein (LDL) apheresis and blood flow determinations in the forearm and leg were performed in 10 patients (age range, 13-49 years; four male, six female) with familial hypercholesterolemia (eight homozygous, two heterozygous). To perform LDL apheresis, plasma was first separated by a polysulphone hollow fiber filter; then, LDL was selectively removed from plasma by dextran sulphate cellulose beads packed in columns. Blood flows in the forearm and leg were determined at rest and during a reactive hyperemia test (peak flow). This test was performed noninvasively by a strain-gauge plethysmograph with semicontinuous registration of arterial blood flow variables before the first apheresis and 3 weeks after the last of six procedures for apheresis. Resting arterial blood flows in the forearm and leg were slightly increased after repeat LDL apheresis (p less than 0.05). Peak blood flow in the leg significantly increased (+34%, p less than 0.01). No change in peak blood flow in the forearm was observed. Systolic blood pressures were slightly but significantly reduced (p less than 0.05); forearm peripheral resistances were also reduced (p less than 0.05). Flow response was not related to LDL receptor status. Blood and plasma viscosities were determined before and 7 days after the last apheresis. Blood viscosity was significantly reduced after LDL apheresis at shear rates of 11.25-450 sec-1. Plasma viscosity did not change.

Improved reactive hyperemia test after plasma exchange in familial hypercholesterolemia.

By using a non-invasive methodology of vascular diagnosis, ECG-triggered strain-gauge plethysmography, 5 patients with familial hypercholesterolemia (FH) (3 homozygous, 2 heterozygous) were evaluated before and during the 1st and 2nd week after plasma exchange (PE). In order to obtain data on the responsiveness to vasodilating stimuli in FH patients undergoing PE, reactive hyperemia test and peak flow determination were also performed. Resting arterial flow over the calf was found to be significantly enhanced after PE. Reactive hyperemia test demonstrated persistent improvement of peak flow following exchange. This study demonstrates useful hemodynamic effects of PE in patients with FH.

[LDL-apheresis in the treatment of familial hypercholesterolemia]. / LDL-aferesi nel trattamento dell'ipercolesterolemia familiare.

Several non-pharmacological treatments have been tested for homozygous familial hypercholesterolemia and, among these, plasma-exchange has been the most safe and effective. A recent development of this procedure is LDL-apheresis, that is the selective removal of atherogenic LDL and the return to the patient of his own LDL-depleted plasma. The method is based on the flowing of hypercholesterolemic plasma on sepharose columns with bound anti-LDL antibodies.