PLASMA FIBRINOGEN AND THE SEDIMENTATION RATE IN RHEUMATOID ARTHRITIS, AND THEIR RESPONSE TO THE ADMINISTRATION OF CORTISONE AND ADRENOCORTICOTROPIC HORMONE (ACTH) 1

Abstract

In active rheumatoid arthritis, the level of the plasma fibrinogen is almost always raised and appears to be the major factor responsible for the increased sedimentation rate in this disease. The admn. of cortisone or ACTH in therapeutic doses usually results in a dramatic fall in the plasma fibrinogen and the sedimentation rate. With the relapse which follows the withdrawal of the hormones, both rise again. During the period of rapidly changing levels, the plasma fibrinogen continues to reflect the intensity of the arthritic process, and parallels the clinical course of the disease, while the sedimentation rate lags by 24-48 hrs. The red cells are not immediately influenced by changing fibrinogen levels and that some interval must elapse before the cells assume the settling velocity which should correspond to a new concn. of fibrinogen. In the relapse period, the fibrinogen rebounds to values as much as 50% above pretreatment levels, indicating an increase in the intensity of the disease. Since the sedimentation rate cannot increase much above 100 mm., in the absence of severe anemia, it often fails to reflect these rebound levels. Changes in the serum globulins occur more slowly and present comparatively little relationship to the sedimentation rate.