Immunoradiometric assay of circulating C-reactive protein: age-related values in the adult general population

Abstract

Background: Increased values of C-reactive protein (CRP), the classical acute phase protein, within the range below 5 mg/L, previously considered to be within the reference interval, are strongly associated with increased risk of atherothrombotic events, and are clinically significant in osteoarthritis and neonatal infection.
Methods: A robust new polyclonal-monoclonal solid-phase IRMA for CRP was developed, with a range of 0.05- 10.0 mg/L.
Results: Plasma CRP values in general adult populations from Augsburg, Germany (2291 males and 2203 females; ages, 25-74 years) and Glasgow, Scotland (604 males and 650 females; ages, 25-64 years) were very similar. The median CRP approximately doubled with age, from similar to 1 mg/L in the youngest decade to similar to 2 mg/L in the oldest, and tended to be higher in females.
Conclusion: This extensive data set, the largest such study of CRP, provides valuable reference information for future clinical and epidemiological investigations.