Objective: To investigate the role of bone marrow in arthritis.
Methods: Bone marrow changes over time were investigated in rats with adjuvant-induced and collagen-induced arthritis, using bioassay techniques and histologic analysis.
Results: In both animal models, bone marrow interleukin-1 and interleukin-6 activity began to rise before the onset of arthritis and increased in relation to the progression of arthritis. Enhanced myelopoiesis in the bone marrow was noted in conjunction with the increased cytokine activity.
Conclusion: Bone marrow changes such as those demonstrated in this study may be common to various models of induced arthritis and may have an important role in the pathogenesis of this disease.