The development of cell mediated immunity: very young children have strong LAK activity.

We were interested in evaluating immune function in very young children with cancer who were treated with gamma-interferon on a sequential basis. Though gamma-interferon was reportedly able to enhance NK activity, and while many tumor cells are susceptible to lysis by these cells, this effector mechanism is not fully developed in very young children. Since LAK cells also have anti-tumor activity and are produced in response to stimulation with Interleukin-2, we investigated whether LAK killing might be more readily demonstrable in very young children. We report that LAK activity in this group did not differ significantly from that of adults. This was also true for a small group of neuroblastoma patients tested. Furthermore, as opposed to NK activity, LAK activity was demonstrable following freezing and thawing of PBL.