Lin KM, et al. - Researchers gauged the high-positive rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) levels in nonarthritic patients with chronic hepatitis C virus (HCV) infection. They determined anti-citrullinated protein antibody and total RF in serum from nonarthritic patients with chronic HCV infection (all had HCV RNA viremia). Contrary to RF, findings did not suggest an increase in ACPA in HCV infection. In nonarthritic patients with chronic HCV infection, high-positive RF is not unusually present. In this patient population, they noted a probability of ACPA to have improved value for the diagnosis of RA. A risk factor for high-positive RF in patients with HCV infection may be fatty liver.