Anti-(apolipoprotein A-1) IgGs are associated with high levels of oxidized low-density lipoprotein in acute coronary syndrome.
ApoA-1 (apolipoprotein A-1) is the main component of HDL (high-density lipoprotein) and stabilizes PON-1 (paraoxonase-1), which prevents lipid peroxidation and oxLDL (oxidized low-density lipoprotein) formation. Autoantibodies against apoA-1 [anti-(apoA-1) IgG] have been found in antiphospholipid syndrome and systemic lupus erythematosous, two diseases with an increased risk of thrombotic events, as well as in ACS (acute coronary syndrome). OxLDL levels are also elevated in these diseases. Whether anti-(apoA-1) IgGs exist in other prothrombotic conditions, such as APE (acute pulmonary embolism) and stroke, has not been studied and their potential association with oxLDL and PON-1 activity is not known. In the present study, we determined prospectively the prevalence of anti-(apoA-1) IgG in patients with ACS (n=127), APE (n=58) and stroke (n=34), and, when present, we tested their association with oxLDL levels. The prevalance of anti-(apoA-1) IgG was 11% in the ACS group, 2% in the control group and 0% in the APE and stroke groups. The ACS group had significantly higher median anti-(apoA-1) IgG titres than the other groups of patients. Patients with ACS positive for anti-(apoA-1) IgG had significantly higher median oxLDL values than those who tested negative (226.5 compared with 47.7 units/l; P<0.00001) and controls. The Spearman ranked test revealed a significant correlation between anti-(apoA-1) IgG titres and serum oxLDL levels (r=0.28, P<0.05). No association was found between PON-1 activity and oxLDL or anti-(apoA-1) IgG levels. In conclusion, anti-(apoA-1) IgG levels are positive in ACS, but not in stroke or APE. In ACS, their presence is associated with higher levels of oxLDL and is directly proportional to the serum concentration of oxLDL. These results emphasize the role of humoral autoimmunity as a mediator of inflammation and coronary atherogenesis.
Vuilleumier
Nicolas
N
Division of Immunology and Allergy, Department of Internal Medicine, University Hospital, Geneva, Switzerland.
Charbonney
Emmanuel
E
Fontao
Lionel
L
Alvarez
Montserrat
M
Turck
Natacha
N
Sanchez
Jean-Charles
JC
Burkhard
Pierre R
PR
Mensi
Noury
N
Righini
Marc
M
Reber
Guido
G
James
Richard
R
Mach
François
F
Chevrolet
Jean-Claude
JC
Dayer
Jean-Michel
JM
Frostegard
Johan
J
Roux-Lombard
Pascale
P
D054058:Acute Coronary Syndrome / Q000097:blood* / Q000276:immunology; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016632:Apolipoprotein A-I / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000276:immunology; D020521:Stroke / Q000276:immunology; D055815:Young Adult
D016632:Apolipoprotein A-I; D001323:Autoantibodies; D015415:Biomarkers; D007074:Immunoglobulin G; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein