Reduced serum levels of autoantibodies against monomeric C-reactive protein (CRP) in patients with acute coronary syndrome.

INTRODUCTION Inflammation is pivotal in atherosclerosis. Minor C-reactive protein (CRP) response reflects low-grade vascular inflammation and the high-sensitivity CRP test with levels > or = 3.0 mg/l predicts coronary vascular events and survival in angina pectoris as well as in healthy subjects. We and others recently reported autoantibodies against monomeric CRP (anti-CRP) in rheumatic conditions, e.g. systemic lupus erythematosus (SLE), and a connection between anti-CRP and cardiovascular disease in SLE has been suggested. PATIENTS AND METHODS Anti-CRP serum levels were determined with ELISA in 140 individuals; 50 healthy controls and 90 patients with angiographically verified coronary artery disease of which 40 presented with acute coronary syndrome (ACS) and 50 with stable angina pectoris (SA). RESULTS Significantly lower anti-CRP levels were observed in ACS compared to SA and controls (p=0.019). ACS patients, who had not been prescribed statins before their respective cardiovascular event, had lower anti-CRP (p=0.049). BMI correlated directly to anti-CRP levels in cross section analysis (p=0.043), but there was no association between anti-CRP and smoking or cholesterol. DISCUSSION In ACS, it is plausible that ruptured plaques and inflamed tissue may be more prone to opsonization by monomeric CRP leading to consumption of anti-CRP. Hypothetically, surface-bound anti-CRP could thereby enhance the local inflammation in plaques.