IN-VIVO BIOLOGICAL RESPONSE FOLLOWING LOW-DOSE INTERLEUKIN-2 IN COMPLETE REMISSION B-CELL NON-HODGKINS-LYMPHOMA PATIENTS

The aim of the present study is to verify whether recombinant interleu kin-2 (rIL-2) at low doses is well tolerated in aggressive lymphoma in complete remission (CR), and if there may be a biological justificati on for its use as a remission-maintenance therapy able to reduce the p ercentage of relapses. We treated 6 patients with B-cell non-Hodgkin's lymphoma (B-NHL) in CR following PM-Cytabom with rIL-2 3 IMU s.c. x 5 d per wk, every other wk for 8 wk. Our results show that this treatme nt provokes statistically significant changes in the absolute number o f lymphocytes, eosinophils, CD25(+) and CD122(+) cells and soluble IL- 2 receptors; these doses, however, are not sufficient to modify CD3(+) , CD16(+) and CD56(+) cell values or natural killer and lymphokine act ivated killer cell activity. Thus these findings do not appear to cons titute a biological rationale for the use of rIL-2 at this dose and sc hedule as a remission-maintenance therapy in B-cell NHL. Nevertheless, the results are a valid basis for further study of the use of the sam e rIL-2 doses for a longer period of time in combination with other cy tokines, in the hope that the biological effects can be augmented with out increasing the toxic side effects.