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 detecti on of soluble interleukin-2 receptor (sIL-2R) in Hodgkin disease (HD). In this study, the authors investigated, in a large series of patient s, sIL-2R serum levels in relation to disease features at presentation and prognosis. Their usefulness as markers in the management of indiv idual cases was evaluated. Methods. The sIL-2R serum levels were measu red in 195 patients at diagnosis. In 72 of these patients, sIL-2R seru m levels were also monitored after diagnosis. An additional 87 cases w ere 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) an d 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 = 9 54 +/- 705, Stage B = 1880 +/- 1238 U/ml, P < 0.0001; bulky presentati on = 1958 +/- 1430, nonbulky presentation = 1043 +/- 791 U/ml, P < 0.0 001). Response to treatment was associated with progressive reduction of sIL-2R levels, which were normal in virtually all cases 1 year afte r CR. Significantly greater levels at diagnosis were found in 11 patie nts who experienced a poor response or progression after treatment (P = 0.004). Overall, abnormal data in CR were found in 59 of 159 patient s and 9 of them subsequently experienced a relapse. Conclusions. The s IL-2R serum levels in HD correlate with features at presentation and s ubsequent clinical courses. Higher levels at diagnosis entail a signif icantly higher risk of treatment failure.