CHRONIC INFLAMMATORY ARTHRITIS (RHEUMATOID ARTHRITIS [AR] AND RELATED FORMS, THE CHRONIC PRIMARY YOUTH [JAI]) IS AUTOIMMUNE DISEASES THAT AFFECT 2 % OF THE GENERAL POPULATION. DO THEY HAVE A HETEROGENEOUS CLINICAL COURSE WHICH DIFFERS FROM THAT OF AGGRESTIVIT? FROM THE MILD TO A SERIOUS DISEASE OF THE BONE AND THE EROSION OF THE CARTILAGE, WITH THE DISEASE PROGRESSING STEADILY OVER TIME, WHICH LEADS OVER TIME TO DEFORMIT? AND INFERIT? CAN IT? TO LEAD TO PROBLEMS EXTRARTICOLARI, VASCU