Evaluations of arthritic patients using the well-known scoring systems showed shortcomings for differential diagnosis of cases that were not fulfilling the full diagnostic spectrum for RA or OA; the diagnostic gray-zone (GZ) because of the dependence on findings that are common for various inflammatory conditions as determination of ESR or estimation of serum CRP and the reliance on the disease duration, thus it was mandatory to find another parameter to differentiate these patients according to the type of arthritis. Here, CRP is linked to rheumatoid arthritis.