Increased levels of C‐reactive protein in serum from blood donors before the onset of rheumatoid arthritis

After observing specific serologic abnormalities 5 years before the onset of RA symptoms, we now report increased levels of CRP in blood donors in whom RA later developed; these increases were most common within the 2 years before the onset of symptoms. The preclinical increase in CRP levels was observed both in donors with and in those without serologic abnormalities.