[Establishment of a reference interval for highly sensitive CRP by exclusion of individuals with abnormal values in...

In November, 1999, U.S. Food and Drug Administration approved a highly sensitive CRP(hs-CRP) assay that could assist medical doctors to predict the risk of cardiovascular accidents. Many doctors are now interested in the assay and trying to elucidate the relationship between serum CRP levels and cardiovascular diseases. In the past, it was difficult to establish a valid reference interval of serum CRP because of the poor analytical sensitivity and difficulty in sampling reference individuals. We have established a reference interval of serum CRP for the hs-CRP assay(Dade Behring). The study population consisted of 7,224 individuals(21-81 years old) who received a regular medical check-up. Potentially abnormal samples were excluded, depending on the results of other laboratory tests related to serum CRP variation. The upper limit of the reference interval was 0.15 mg/dl. The serum CRP was higher in smokers than in non-smokers, especially in men.