Elevated Levels of Soluble Interleukin-2 Receptors in Multiple Sclerosis

To the Editor: The expansion of activated, antigen-reactive T-cell populations is dependent on the sequential induction and expression of interleukin-2 (T-cell growth factor) and the interleukin-2 receptor, and the subsequent binding of interleukin-2 to its high-affinity membrane receptor. In a letter in the May 5 issue, 1 Trotter and colleagues have shown elevated serum levels of interleukin-2 in patients with chronic progressive multiple sclerosis. Their findings may reflect a state of ongoing lymphocyte activation, suggesting a commensurate induction and expression of interleukin-2 receptor on circulating T lymphocytes. The high-affinity interleukin-2 receptor is composed of at least two different interleukin-2–binding peptides — . . .