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

Atherosclerosis. 2010 Feb;208(2):324-7. doi: 10.1016/j.atherosclerosis.2009.07.039. Epub 2009 Jul 28.

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.

Publication types

  • Letter
  • Research Support, Non-U.S. Gov't

MeSH terms

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

Substances

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