Antibodies
Against Oxidized LDL - Theory and Clinical Use
A. STEINEROVÁ1, J. RACEK2, F.
STOŽICKÝ3, T. ZIMA4, L. FIALOVÁ5, A. LAPIN6
1Medika
Centrum, 2Institute
of Clinical Biochemistry and Laboratory
Diagnostics, 3Department
of Pediatrics, Charles University Hospital,
Pilsen, 4Institute
of Clinical Biochemistry, First Faculty of
Medicine, 5Institute
of Medical Chemistry and Biochemistry, First
Faculty of Medicine, Charles University, Prague,
Czech Republic and 6Department
of Laboratory Medicine, Sophien Hospital, Vienna,
Austria
Received April 10, 2000
Accepted September 4, 2000
Summary
Modification of low density lipoprotein (LDL)
particles due to oxidation, glycation and binding
of advanced glycation end-products (AGEs) or
malondialdehyde (MDA, a final product of lipid
peroxidation) is considered most important in the
process of atherogenesis. Oxidatively modified
LDL are distinguished by another receptor type,
which was discovered on the surface of
macrophages and was called the scavenger
receptor. Uncontrolled intake of LDL converts
macrophages to foam cells; their accumulation
under the vascular endothelium is considered as
the first stage of atherosclerosis. Oxidation of
LDL is a complex process taking place in both the
extra- and intracellular space. At the end of
this oxidative process, modified LDL particles
show chemotactic, cytotoxic and immunogenic
properties. Oxidized LDL express a large number
of epitopes and cause production of polyclonal
autoantibodies against these products, especially
against apoB100 modified by MDA and
4-hydroxynonenal. IgoxLDL (antibodies against
oxidized LDL) can be demonstrated either directly
in intimal lesions or as a component of
circulating immune complexes. IgoxLDL do not form
a homogeneous group but a varied mixture of
antibodies-isoantibodies caused by HDL and LDL
polymorphism, antibodies against the lipid phase
of LDL and antibodies against modified apoB100 of
the immunoglobulin class IgA or IgG. Antibodies
against oxLDL were found in many diseases other
than atherosclerosis such as diabetes mellitus,
renovascular syndrome, uremia, rheumatic fever,
morbus Bechtjerev or lupus erythematodes.
Newborns have practically the same levels of
IgoxLDL as their mothers; however, these values
did not differ from those in the healthy
population of non-pregnant women of the same age.
The decrease in IgoxLDL titer was very slow and
lasted many months; that is why this parameter
cannot be considered suitable for describing the
rapid changes during oxidative stress of the
organism. Positive correlation of IgoxLDL with
antiphospholipids and other antibodies was
repeatedly demonstrated; their determination can
thus be used as a marker for the description of
total production of autoantibodies in various
diseases. The changes and correlations of
IgoxLDL, anti-b-2-glycoprotein I IgG and
antiphospholipid antibodies support the
immunological link between thrombotic and
atherosclerotic processes in the human body.
Key
words
IgoxLDL · Low density lipoprotein ·
Autoantibodies · Atherosclerosis · Oxidative
stress
Reprint
requests
Prof. J. Racek, M.D., Ph.D., Institute of
Clinical Biochemistry and Laboratory Diagnostics,
Charles University Hospital, Alej Svobody 80,
CZ-304 60 Plzeň, Czech Republic. Fax: +
420-19-710 4234 , E-mail: racek@fnplzen.cz
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