Whole Blood Selective LDL-Apheresis: A Comparison of Two Different Adsorbers

The effects of LDL-apheresis with whole blood adsorption were compared in five patients with severe familial and ARH hypercholesterolemia, using two different sorbents, polyacrylic acid with the DALI system and dextran sulfate with the DX21 system. The patients were treated bimonthly with both systems at random. For each patient, the same number of procedures with both systems was considered, ranging from 2 to 11 for each technique. During a period of observation of 26 months, a total of 80 LDL-apheresis, 40 with the DALI system and 40 with the DX21, with equivalent volumes of treated whole blood was evaluated (mean blood volume treated: 8151 mL). Total and LDL cholesterol were effectively lowered with both techniques. The mean percentage reduction of total cholesterol and LDL-cholesterol respectively was 54.1±7.7% and 62.3±9% with the DALI system, 52.7±7.8% and 59.2±9.5 with the DX21: t-test for paired data showed p: 0.01 for LDL-cholesterol. The reduced removal of LDL-C with dextran sulfate, either within the same patient or all the patients taken together was of a very limited amount compared to polyacrylic acid. The superiority of one over the other sorbent cannot be affirmed: further studies on a higher number of procedures and patients, together with an evaluation of biocompatibility effects, compared to polyacrylic acid may clarify and make evident a significant difference in efficacy between the two systems.

A three month-old infant with severe hyperchylomicronemia: molecular diagnosis and extracorporeal treatment

OBJECTIVE

Chylomicronemia syndrome presenting in childhood is a rare recessive disorder due to mutations of lipoprotein lipase (LPL) and more rarely of APOC2, APOA5, GPIHBP1 or LMF1 genes. It often requires urgent and suitable treatment to avoid acute pancreatitis. The aim of this study was the molecular characterization and treatment of a 3 month-old infant with plasma triglycerides (TG) > 300 mmol/L.

METHODS

All candidate genes were sequenced. The patient was submitted to one plasma-exchange (PEX) procedure and subsequently to a rigid lipid-lowering diet (milk: Monogen(®)).

RESULTS

The proband was homozygous for a novel LPL mutation (c.242G > A, p.G81D) which in silico results pathogenic. After PEX, which was well tolerated, TG dropped to 64 mmol/L. During 5-month follow-up there was a clear trend towards lower and stable TG values.

CONCLUSION

PEX is applicable in subjects with very low body weight when the extreme severity of the clinical picture has no therapeutic alternatives.

Lipid and low-density-lipoprotein apheresis. Effects on plasma inflammatory profile and on cytokine pattern in patients with severe dyslipidemia

Available evidence on the effects of therapeutic plasmapheresis (TP) techniques and in particular lipid- and LDL-apheresis (LDL-a) on plasmatic inflammatory mediators including cytokines were reviewed. Studies on this issue are not numerous. However, the review of existing evidence clearly suggests an active role of apheresis on the profile of inflammatory molecules and on cytokine pattern in plasma. These non-lipid-lowering effects can be defined to some extent pleiotropic or pleiotropic-equivalent. Although further studies are desirable, the data reported in this review confirm that lipid- and LDL-a not only show acute lipid-lowering and cholesterol-lowering effects, but also efficacy in reducing several proinflammatory peptides, including cytokines. This effect was not related apparently to lipids and lipoproteins reduction. Thus, TP (lipid- and LDL-a), commonly utilized in the treatment of severe genetically determined lipid disorders, unresponsive to hypolipidemic drugs, offers new possibilities of interpretation of its role in the mechanisms leading to the blockade of atherosclerotic lesion development and progression. The ability of TP on short-term to induce such a profound change in the plasmatic metabolic and inflammatory profiles must be kept in mind in the treatment of acute coronary syndromes, before and after interventions of coronary revascularization, and in the acute phase of cerebrovascular ischemia, at least in patients with severe dyslipidemia. Further studies are needed, in particular aimed at assessing if circulating cytokines may be downregulated by TP not only by direct removal, but through indirect effects on both gene translation and transcription perhaps via the cytokine receptor function.

Safety and effectiveness of long-term LDL-apheresis in patients at high risk

Since its introduction more than 10 years ago, LDL-apheresis has gained much interest and has proven its clinical utility in patients who cannot be adequately treated by diet and drug therapy alone. A number of clinical studies have clearly demonstrated that regular LDL-apheresis not only favourably influences the progression of coronary artery disease, but also decreases the incidence of cardiovascular events and prolongs survival time of coronary patients at high risk. Both hypercholesterolemia and hyperfibrinogenemia show a high prevalence in heart transplant recipients and seem to cause direct effects on survival time. Heparin-mediated extracorporeal LDL-precipitation-LDL-apheresis has proven to be very successful in this group of patients, which may be caused by the simultaneous removal of LDL, lipoprotein (a) and fibrinogen, and also because LDL-apheresis decreases the susceptibility of LDL to oxidation. In addition, there is clear clinical and experimental evidence that LDL-apheresis rapidly improves the endothelial-mediated vasomotion. Not unexpectedly, there are differences in specificity and side-effects between the systems used and these deserve more attention for future routine clinical use.