Effects of interleukin-4 on the in vitro growth of human lymphoid and plasma cell neoplasms

Recombinant human interleukin-4 (rhIL-4) has pleiotropic biologic effects including stimulation of normal B-cell growth. We investigated the effects of rhIL-4 on the in vitro growth of 35 fresh human lymphoid and plasma cell malignancies. Inhibition of growth was seen in 52% and 60% of multiple myeloma and lymphoma specimens, respectively. Growth was stimulated relative to control in 8.6% (3 of 35) of the tumors tested. Immunophenotyping showed that tumors displaying growth stimulation expressed surface markers associated with a poor clinical prognosis. Our findings support the clinical evaluation of rhIL-4 as a therapeutic agent in selected patients with lymphoid and plasma cell neoplasms.