Prevalence and function of anti-lipoprotein lipase auto-antibodies in type V hyperchylomicronemia.

Abstract

PURPOSE:

Type V hyperlipidemia (HTG V) characterized by accumulation of both chylomicrons and VLDL results from a complex combination of genetic and environmental factors. However, a large proportion of sporadic cases remains largely unexplained. In a few cases, in a context of autoimmunity, auto-antibodies inhibiting lipoprotein lipase (LPL) activity have been incriminated. To establish their contribution to common type V hyperlipidemia in subjects with no apparent evidence of autoimmune background, we systematically screened the presence of these antibodies and their inhibition properties.

METHODS:

Screening for circulating anti-human LPL immunoglobulin G (anti-hLPL IgG) was carried out by western blotting in 63 subjects with HTG V and 77 controls. Inhibition of lipolytic activity by plasma from these patients was measured ex vivo.

RESULTS:

Anti-hLPL IgG was detectable in plasma from both controls and subjects with HTG V. After establishment of a threshold value corresponding to the 95th percentile of the control population, 27% of subjects with HTG V were found to have abnormal antibody levels (P<0.001). Only plasma obtained from these hyperchylomicronemic subjects with a high level of anti-hLPL IgG inhibited triglyceride hydrolysis whereas plasma from controls or HTG subjects with normal anti-hLPL IgG levels had no inhibitory effect (-13.5+/-3.4% vs 1.6+/-3.4%; P=0.04). However, no correlation was observed between anti-hLPL IgG levels, inhibitory effect and plasma triglyceride concentration.

CONCLUSION:

High levels of anti-hLPL immunoreactivity could be detected in only one out of four adult patients with type V hyperchylomicronemia. Furthermore, only a minority of these subjects (less than 10%) displayed both high anti-hLPL IgG levels and substantial inhibition (>20%) of plasma lipolysis. These auto-antibodies, in this setting only, might contribute to the occurrence of a minority of sporadic type V dyslipidemia cases.

• Authors: Myriam Moret, Valérie Pruneta-Deloche, Agnès Sassolas, Christophe Marcais, Philippe Moulin
• Journal: Atherosclerosis (Atherosclerosis) Vol. 208 Issue 2 Pg. 324-7 (Feb 2010) ISSN: 1879-1484 [Electronic] Ireland
• PMID: 19695572 (Publication Type: Letter, Research Support, Non-U.S. Gov't)
• Copyright: Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

Chemical References

• Autoantibodies
• Chylomicrons
• Immunoglobulin G
• Ligands
• Triglycerides
• Lipoprotein Lipase

Topics

• Autoantibodies (chemistry)
• Autoimmunity
• Blotting, Western
• Chylomicrons (chemistry)
• Humans
• Hydrolysis
• Hyperlipidemias (blood, epidemiology, immunology)
• Immunoglobulin G (chemistry)
• Ligands
• Lipoprotein Lipase (antagonists & inhibitors, blood, immunology)
• Models, Biological
• Triglycerides (chemistry)