*4.3. Clinical Laboratory Assays*

C-reactive prtein (CRP) y Rheumatoid factor (FR) was determined by an inmmunoturbidimetry assay in an Atellica Solution® CH (Siemens Healthineers, Erlangen, Germany), with 0–5 mg/L being the normal range for CRP and 3.5–90 IU/mL for RF. Anti-CCP was determined by a fluoroenzimo-immunoassay (Inmunocap 250, Thermofisher Scientific, Waltham, MA, USA) with a normal range under IU/mL.
