Evaluation of a semiquantitative C-reactive protein latex slide test as compared to quantitative turbidimetric measurement in hospital laboratory practice.

Serum C-reactive protein (CRP) concentrations of 708 patients with suspected bacterial disease were estimated with a semiquantitative CRP latex slide test using cut-off levels of 20 and 40 mg/l and with quantitative turbidimetric technique. Latex slide tests gave 11.8% (80/708) discordant results. About 7% of tests gave clear disconcordant results (5% of those were positive and 2% negative tests). We conclude that CRP latex slide test is not useful in emergency laboratory in hospital material with a high incidence of bacterial infections.