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

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. Cancer 1993; 72:201–6. Copyright © 1993 American Cancer Society