Apport des nouveaux examens biologiques au diagnostic de la polyarthrite rhumatoïde

The diagnosis of rheumatoid arthritis (RA), notably that of early arthritis, rests on a cluster of clinical and biological arguments. Among biological test, three families of autoantibodies (Abs) have been selected: anti-citrullinated peptide Abs (ACPA), rheumatoid factor (RF) and antinuclear Abs (ANA). ACPA are highly specific but the sensitivity of the test (35-80%) vary depending on the assay: anti-CCP3 > anti-CCP2 = anti-MCV > anti-perinuclear Abs > anti-"keratin" Abs. ACPA associated with RF render less difficult the early diagnosis of RA and ANA also exist in 65-75% of these patients, some being specific for native DNA, others for soluble nuclear antigens.