High serum interleukin-2 receptor levels correlate with a poor prognosis in children with Hodgkin's disease.

To improve the biologic evaluation of Hodgkin's disease, we determined serum interleukin-2 receptor (IL2R) levels in 88 children with this tumor. In patients with stage III or IV disease, the median receptor level was significantly higher than in patients with lower stages (3195 vs. 1087 U/ml, p = 0.0001). Similarly, the median level for children with stage B disease was 3262 U/ml, compared with 999 U/ml for those lacking constitutional symptoms (p = 0.0001). Patients with very high soluble IL2R levels (greater than or equal to 5000 U/ml) were significantly more likely to fail treatment (p = 0.01), even when the analysis was restricted to groups with advanced disease: stages III and IV (p = 0.0001). When entered in the Cox-proportional hazards model with other potentially useful prognostic factors, soluble IL2R level was found to be an independent predictor of treatment outcome. The relationship of high serum IL2R levels to an adverse clinical outcome in Hodgkin's disease may be explained by a model in which the soluble receptor competes for the ligand with the cellular receptor on normal lymphocytes, thus blocking antitumor immunity dependent on interleukin-2. Alternatively, high serum levels of IL2R may simply reflect increased release of the receptor from activated malignant cells in patients with advanced disease or an otherwise poor prognosis.