[Significance of soluble interleukin-2 receptor alpha chain in the management of patients with malignant lymphoma: a multi-center study].

A multi-center series of 117 patients with malignant lymphoma were analyzed to evaluate the clinical significance of soluble interleukin-2 receptor alpha chain (sIL-2R alpha). The initial levels of sIL-2R alpha ranged from 277 U/ml to 22,800 U/ml with a mean level of 3,451 +/- 4,268 U/ml and a median level of 1,600 U/ml. The sIL-2R alpha levels of the diffuse lymphoma/intermediate-grade subtypes defined by the LSG classification/Working Formulation were higher than those of the follicular lymphoma/low-grade subtypes. There was a tendency for B-cell lymphomas to show higher sIL-2R alpha levels than T-cell lymphomas. The sIL-2R alpha level was correlated with the Ann Arbor clinical stage (I, II versus III, IV), presence or absence of B symptoms, and performance status (0, 1 versus 2, 3, 4) of the patients. The sIL-2R alpha levels were in good accordance with the four risk groups defined by the International Prognostic Indices. Of 21 patients whose tumor burden was serially measured, the coefficients of correlation between sIL-2R alpha and tumor mass were > 0.6 in 18 cases. Sixty-two patients achieved complete remission (CR) during the study; the initial and minimum sIL-2R alpha levels were lower than those of the non-CR patients. This study confirmed that sIL-2R alpha is a convenient and useful marker in the management of malignant lymphoma.