Effect of leukopenia and leukocytosis on tumor growth and survival time.Part II. Leukocytosis

Experiments with the effects of leukocytosis on tumor growth and animal survival time using the V-2 carcinoma transplant in the rabbit failed to show any effect of the leukocytosis per se. However, the present study exploring the Leukocytosis-Inducing Factor (LIF) isolated in leukophoresed plasma found it to be present in the plasma of cancerous rabbits and present to a greater extent in the leukopenic plasma of normal leukophoresed animals. The target cell of the LIF appears to be neutrophil-forming tissue with production of neutrophilic band cells and metamyelocytes. The optimal injection volume and time interval following leukophoresis-leukopenia for achieving maximum leukocytosis suggest a “time-dose” relationship. There was a marked absolute increase in leukocyte response of the cancerous recipients over noncancerous recipients following the injection of cancerous and noncancerous leukopenic plasma as well as both relative and absolute increase with the injection of the former over the latter into both recipients. The interrelationship of chemotherapy, radiation, and leukophoresis is discussed in reference to their common denominator of leukopenia and consequent tumor suppression, immunosuppression, and LIF production which are probably motivated by the Host Resistance Factor (HRF).