The rheumatoid disease is a systematic morbid disease with inflammatory character. Diagnostically it is characterized by VES, α-2 gammaglobulins and PRC increases and by the presence of rheumatoid factors. In this test the rheumatoid factors, eventually present in the serum, agglutinate with rabbit erythrocytes sensitized with rabbit immunoglobulins to form an easily visible agglomerate (Waaler-Rose method).