Bone marrow microenvironment of patients with systemic lupus erythematosus.

In an attempt to clarify the hematologic abnormality in systemic lupus erythematosus (SLE), we studied the bone marrow microenvironment of 8 women with this disease. The number of fibroblast colonies was similar to that of healthy control individuals. Culture supernatants of monocytes obtained from the patients with SLE showed a diminished production of the hemopoietic growth factor required to stimulate bone marrow fibroblasts. As the activity of the humoral factor released from SLE monocytes was diminished, such a reduction may play a role in the pathogenesis of the hematologic abnormality seen in SLE.