Interleukin-2-mediated growth of leukemic cells in lymph nodes of patients with adult T-cell leukemia/lymphoma.

We investigated the effect of interleukin-2 (IL-2) on tumor growth of primary adult T-cell leukemia/lymphoma (ATL) cells in biopsied lymph node cells obtained from 14 patients (seven [corrected] with acute-type disease, one with chronic-type disease and six [corrected] with lymphoma-type disease). Biological activity of IL-2 in culture supernatants of the cells was detected in six out of 12 cases. The IL-2 mRNA in the lymph node cells was detected in four out of nine patients by northern blotting. However, it was detected in all nine patients examined by reverse polymerase chain reaction (PCR) method. Lymph node cells from 12 out of 14 patients showed a high or moderate proliferative response to IL-2; the remaining two patients showed a slight response. These results suggest that malignant growth of primary tumor cells in lymph nodes may be associated with the IL-2-IL-2 receptor system in patients with ATL more frequently than had been previously thought.