Serum soluble IL-2 receptor as a tumor marker in patients with hairy cell leukemia

Abstract

Activated T cells synthesize and express a cell membrane-bound receptor for interleukin-2 (IL-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 IL-2 receptor on the cell membrane. The sera of 26 patients with hairy cell leukemia were examined for the presence of a soluble IL-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 IL-2 receptor ranging from five to 60 times the highest level observed in normal control sera. In individual patients changes in the level during therapy correlated well with clinical assessments of tumor response; levels fell to near the normal range in patients responding to therapy. Patients not responding to interferon alpha had no significant change in the soluble IL-2 receptor level. These results suggest that hairy cells secrete a soluble IL-2 receptor and that serial measurements of the level of this receptor in the serum can be used as a noninvasive means to assess disease response to therapy.

Serum interleukin (IL)‐1, IL‐2, sIL‐2Ra, IL‐6 and thrombopoietin levels in patients with chronic myeloproliferative diseases

“…It is well known that increased levels of the soluble sIL-2Ra in biological fluids correlate with increased T-and B-cell activation and immune system activation (Waldmann, 1986). Many studies in the literature suggest a correlation between elevated sIL-2Ra and disorders that are associated with cellular immune activation (Semenzato et al, 1987;Steis et al, 1988). Furthermore, Motoi et al (1989) demonstrated that serum sIL-2Ra levels are a useful clinical indicator of the leukaemic cell burden in vivo, as leukaemic cells from CML patients with blastic crisis expressed and released IL-2 receptor (Tac antigen) (Motoi et al, 1989).…”

Serum levels of soluble interleukin‐2 receptor in hairy cell leukaemia: a reliable marker of neoplastic bulk

“…The serum level of sIL-2K in HCL at diagnosis is extremely high (Greene et al, 1986;Chilosi et al, 1987) and can be regarded as a useful diagnostic marker in the context of the clinical picture of the disease (Pizzolo et al, 1987a). Interestingly, in HCL patients successfully treated with alpha interferon (alpha-IFN) a decrease in serum sIL-2R level parallels the improvement in haematologic parameters and the reduction of splenomegaly and of BM HC infiltration (Chilosi et al 1987;Steis et al, 1988).…”

Immunophenotype of hairy‐cell leukemia

“…This antigen, which is characteristic of activated T cells, has also been found on special categories of activated B cells (1,32). In HCL this antigen is especially strongly expressed and it can even be secreted (33,34). B-CLL does not normally express IL2-R but can be induced to do so with phorbol ester or other inducers (35).…”