Antibodies to C reactive protein.

BACKGROUND: C reactive protein (CRP) is a known indicator of inflammation. Serum CRP is often raised in patients with inflammatory conditions. OBJECTIVE: To determine whether individuals make antibodies to CRP and whether this might affect serum CRP concentrations. METHODS: An enzyme linked immunosorbent assay was developed for the detection of antibodies to CRP. Specificity of the reaction was determined by inhibition of the reaction. RESULTS: Sera from 413 patients were tested and 25 were found to be positive, particularly in patients with rheumatic diseases. Levels of anti-CRP did not correlate with serum CRP levels. CONCLUSIONS: The presence of low CRP levels may not reflect the presence of antibodies to CRP.