Serum levels of soluble interleukin-2 receptor in Hodgkin disease. Relationship with clinical stage, tumor burden, and treatment outcome.

ABSTRACT

BACKGROUND: Previous studies suggested a possible role for the detection of soluble interleukin-2 receptor (sIL-2R) in Hodgkin disease (HD). In this study, the authors investigated, in a large series of patients, sIL-2R serum levels in relation to disease features at presentation and prognosis. Their usefulness as markers in the management of individual cases was evaluated. METHODS: The sIL-2R serum levels were measured in 195 patients at diagnosis. In 72 of these patients, sIL-2R serum levels were also monitored after diagnosis. An additional 87 cases were tested only in complete remission (CR), and 25 were tested only at relapse. RESULTS: The sIL-2R levels at diagnosis were increased (mean +/- 1222 +/- 1012 versus 331 +/- 145 U/ml in controls, P < 0.0001) and correlated with the stage and tumor burden (Stages I and II = 1058 +/- 1007, Stages III and IV = 1502 +/- 942 U/ml, P = 0.003; Stage A = 954 +/- 705, Stage B = 1880 +/- 1238 U/ml, P < 0.0001; bulky presentation = 1958 +/- 1430, nonbulky presentation = 1043 +/- 791 U/ml, P < 0.0001). Response to treatment was associated with progressive reduction of sIL-2R levels, which were normal in virtually all cases 1 year after CR. Significantly greater levels at diagnosis were found in 11 patients who experienced a poor response or progression after treatment (P = 0.004). Overall, abnormal data in CR were found in 59 of 159 patients and 9 of them subsequently experienced a relapse. CONCLUSIONS: The sIL-2R serum levels in HD correlate with features at presentation and subsequent clinical courses. Higher levels at diagnosis entail a significantly higher risk of treatment failure.