[Clinical significance of serum soluble interleukin-2 receptor level in patients with non-Hodgkin's lymphoma].

The aim of this study was to assess the clinical significance of serum soluble interleukin-2 receptors (sIL-2R) in non-Hodgkin's lymphoma (NHL). Using a sandwich ELISA method, serum sIL-2R levels were measured in 720 samples from 87 patients with NHL (including 65 untreated patients) and 36 patients with other diseases such as infectious mononucleosis. The mean serum sIL-2R level in NHL was 4,017 U/ml (mean +/- SD, 4017 +/- 6352 U/ml). Patients in clinical stages III/IV (5116 +/- 6629) had significantly higher sIL-2R levels than those in clinical stages I/II (813 +/- 611). Patients with sIL-2R levels exceeding 8,000 U/ml had significantly lower survival rates (2-year survival: 12.3%) than those with sIL-2R levels below 8,000 U/ml (2-year survival: 76.0%) (P < 0.01). Multivariate analysis of variables including age, clinical stage, LDH, CRP, performance status, number of extranodal diseases, and sIL-2R demonstrated that sIL-2R and LDH were significant prognostic indicators of overall survival. The upper limit of the 95% confidence interval for maximum sIL-2R level in follow-up of patients with complete remission was 2,014 U/ml. Although an increased sIL-2R level of around 2,000 U/ml in the remission stage did not necessarily suggest relapse of NHL, it did seem to warrant careful follow-up. The serum sIL-2R level appears to reflect tumor activity and may prove to be a useful prognostic indicator in patients with NHL.