Serum Soluble IL-2 Receptor as a Tumor Marker in Patients

Activated T cells synthesize and express a cell membranebound receptor for interleukin-2 (lL-2) and have recently been shown to secrete a soluble form of the same receptor. Hairy cell leukemia is a chronic disorder caused by expansion of a clonal population of an unusual mononuclear cell of B cell origin. These cells have previously been shown to express an 11-2 receptor on the cell membrane. The sera of 26 patients with hairy cell leukemia were examined for the presence of a soluble 11-2 receptor before and during therapy with either recombinant interferon alpha-2a or 2’-deoxycoformycin. Before therapy. all patients had markedly elevated levels of this soluble 11-2 receptor ranging from five to 60 times the highest level observed in normal