Study of factors determining the usefulness and complications of leukocyte transfusions

Fifty-two patients suffering from severe neutropenia were treated with leukocyte transfusions. Except for two of these patients, who received cells from normal donors, the cells transfused were obtained from patients with chronic myeloid leukaemia. In 50 per cent of the patients the transfusions were followed by disappearance of fever and associated signs of infection, and a rise in the leukocyte count, which was dependent on the establishment of a graft by the transfused cells. The rise in leukocyte count occurred when chronic myeloid leukaemia cells were transfused into the recipients. The beneficial symptomatic effects of the transfusions were obtained only when a sufficiently large number of cells was given. In twenty-four patients with acute leukaemia given these transfusions nine remissions were induced by this treatment. No anticancer effect was noted in diseases other than acute leukaemia. The antileukaemic effect is related to a graft versus host reaction. The reaction produced by the transfusions of cells was identical with the secondary syndrome that complicates the grafting of allogeneic bone marrow in man. The frequency of this syndrome did not depend on the underlying disease but, as with the antileukaemic effect in acute leukaemia, on the number of cells transfused. Incubation of the cells to be transfused for two hours at 37 °C. reduced the frequency and severity of the secondary syndrome without affecting their ability to produce a symptomatic effect. Storage of the transfused cells at −70 °C. reduced the severity and frequency of the secondary syndrome but also the value of these transfusions to combat the agranulocytosis syndrome.