Enhanced natural killer cell activity and long survival in acute non-lymphoblastic leukaemia. A case report

Natural killer (NK) cell activity is capable of mediating an antileukaemic effect. Accordingly this phenomenon was studied during the course of the 13-year disease-free survival of a patient after treatment for acute non-lymphoblastic leukaemia in order to test the hypothesis that concurrent tuberculosis may have induced this cell population and thereby modulated clinical and haematological course of the disease. An unusually high spontaneous cytotoxicity was demonstrated, which may have played a role in the prolonged survival. This latter finding is consistent with the theoretical possibility that chronic inflammation may enhance the activity of this particular cell population and supports the concept that therapeutic modulation of NK activity remains an achievable goal in clinical medicine.