Differences in human antioxidized LDL autoantibodies in patients with stable and unstable angina.
BACKGROUND
Autoantibodies to oxidized LDL (anti-oxLDL) have been found in the serum of patients with coronary artery disease (CAD). This study was designed to compare the differences in anti-oxLDL titers and isotypes in unstable and stable angina patients and to correlate these results with known markers of active inflammation in CAD.


METHODS
Thirty patients from a tertiary referral general hospital with documented CAD were studied. Anti-oxLDL IgG titers and its isotypes, high sensitivity C-reactive protein (hsCRP) and serum amyloid A (SAA) were measured.


RESULTS
The anti-oxLDL IgG titer was lower (p=0.03) in the unstable angina group compared to the stable angina patients (0.084+/-0.102 OD versus 0.195+/-0.149 OD, respectively). The predominant IgG isotype in both groups was IgG2. IgG4 was significantly higher (0.270+/-0.146 OD, p=0.04) in the unstable angina group versus patients with stable angina (0.198+/-0.019 OD). There was a significant inverse correlation between anti-oxLDL and hsCRP and SAA in this sample population (R=0.37, p<0.05 and R=0.36, p<0.05, respectively).


CONCLUSIONS
Patients with unstable angina have lower levels of anti-oxLDL IgG in the acute setting of CAD. Plaque instabilization does not seem to acutely modify the isotype subsets of anti-oxLDL IgG in these patients.
Fernandes
Juliano L
JL
Heart Institute (InCor), University of Sao Paulo Medical School, Brazil. julianofernandes@bigfoot.com
Orford
James L
JL
Garcia
Concilia
C
Coelho
Otavio R
OR
Gidlund
Magnus
M
Blotta
Maria Heloisa S L
MH
D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000276:immunology*; D000789:Angina, Unstable / Q000175:diagnosis / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D003324:Coronary Artery Disease / Q000276:immunology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007132:Immunoglobulin Isotypes / Q000097:blood; D008077:Lipoproteins, LDL / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012008:Recurrence
D001323:Autoantibodies; D015415:Biomarkers; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D002097:C-Reactive Protein