[Clinical significance of soluble interleukin-2 receptor in multiple myeloma]

Increased levels of soluble interleukin-2 receptor (sIL-2R) have been noted in the sera of patients with various diseases such as adult T cell leukemia, malignant lymphoma and autoimmune diseases. Using an enzyme-linked immunoabsorbent assay, we assessed sIL-2R levels in the sera of 16 patients with multiple myeloma (MM) and 27 normal subjects. There was a significant increase in the levels of sIL-2R in the patients with myeloma (963 +/- 523 U/ml) compared to normal subjects (213 +/- 80 U/ml). The levels of sIL-2R corresponded well with the clinical stage, M-protein, serum IL-6 and serum beta 2 microglobulin levels. Taking the evidence that the CD4/CD8 ratio decreased as the disease worsened into consideration, the increase in the serum sIL-2R levels of the patients with MM is considered to have some correlation with B and T cell activation through various cytokines including IL-6. Furthermore such evidence would support the role of sIL-2R as a disease monitor of MM.